BIOE 391 Research Project

BIOE 391 Research Project

Goal: To learn about recently published applications of numerical methods or statistics and to convey that information effectively to other BIOE 391 students

Format : Groups of 2-4 people will prepare a short research paper (5 pages maximum) and a 15 minute presentation on a numerical or statistical topic of their . Appropriate projects ideas could include writing a Matlab program to quantify or image a biological system, conducting a statistical analysis of a data set, conducting a review of an application of numerical methods on a specific topic (i.e analysis of a physiological measurement), or investigating a numerical or statistical tool that was not covered in class (with the goal of teaching it to a BIOE audience). Informal minutes of group meetings (i.e. handwritten notes, not a formal document) stating the time and the attendees should be attached to the written report.

Topics: Peer reviewed journal articles that could be used to help with topic ideas can be found at the end of this document. These are only suggestions. Please brainstorm with your group members and find out the teams relative strengths so that you can develop an interesting and effective presentation & paper.

Timeline: A preliminary proposal will be due on 10/31/06 (see schedule). The proposal should specify the group members and project topic (1 paragraph abstract).

The projects will be presented during the last 2 weeks of class. A sign up sheet will be distributed in class. All reports will be due on the last day of class.

GOAL/Grading

Research project components	Possible points	Obtained points
Appropriate research topic: project must be relevant to the course material and interesting to the audience	10
Level of difficulty: the level of complexity of the research topic and the depth of examination of the topic	15
Analytical analysis: demonstration that the group understands the mathematical basis for their topic. For example, this could include an EXCEL or MATLAB example of their topic, a comprehensive explanation of their topic, or a test or homework question that illustrates an application of the topic.	25
Written communication skills: research report should be well written, without typos and well documented with citations and a bibliography (minimum 3 sources)	20
Oral presentation: classroom presentation should be clear, dynamic, and effectively convey information to the class. All members of the team should participate in the discussion of their research project.	20
Teamwork: demonstration that the group functioned as a fully integrated team. This could be shown through group meeting notes that demonstrate group planning, designation of leaders for each goal, cooperation and collaboration. This can also be shown in the oral presentation.	10
Creativity EXTRA CREDIT: incorporation of some original, interesting, or inventive ideas into their project. This could be a demonstration of novel computer program, an imaginative presentation style, or an artistic element in the research report.	5

Resarch Topic Ideas

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1: N Engl J Med. 2006 Jul 20;355(3):260-9.

Related Articles, Links

Comment in:

· N Engl J Med. 2006 Jul 20;355(3):308-10.

Outcome of heart failure with preserved ejection fraction in a population-based study.

Bhatia RS, Tu JV, Lee DS, Austin PC, Fang J, Haouzi A, Gong Y, Liu PP.

Heart & Stroke/Richard Lewar Centre of Excellence, University of Toronto, and the Division of Cardiology, Toronto General Hospital, University Health Network, Toronto, ON, Canada.

BACKGROUND: The importance of heart failure with preserved ejection fraction is increasingly recognized. We conducted a study to evaluate the epidemiologic features and outcomes of patients with heart failure with preserved ejection fraction and to compare the findings with those from patients who had heart failure with reduced ejection fraction. METHODS: From April 1, 1999, through March 31, 2001, we studied 2802 patients admitted to 103 hospitals in the province of Ontario, Canada, with a discharge diagnosis of heart failure whose ejection fraction had also been assessed. The patients were categorized in three groups: those with an ejection fraction of less than 40 percent (heart failure with reduced ejection fraction), those with an ejection fraction of 40 to 50 percent (heart failure with borderline ejection fraction), and those with an ejection fraction of more than 50 percent (heart failure with preserved ejection fraction). Two groups were studied in detail: those with an ejection fraction of less than 40 percent and those with an ejection fraction of more than 50 percent. The main outcome measures were death within one year and readmission to the hospital for heart failure. RESULTS: Thirty-one percent of the patients had an ejection fraction of more than 50 percent. Patients with heart failure with preserved ejection fraction were more likely to be older and female and to have a history of hypertension and atrial fibrillation. The presenting history and clinical examination findings were similar for the two groups. The unadjusted mortality rates for patients with an ejection fraction of more than 50 percent were not significantly different from those for patients with an ejection fraction of less than 40 percent at 30 days (5 percent vs. 7 percent, P=0.08) and at 1 year (22 percent vs. 26 percent, P=0.07); the adjusted one-year mortality rates were also not significantly different in the two groups (hazard ratio, 1.13; 95 percent confidence interval, 0.94 to 1.36; P=0.18). The rates of readmission for heart failure and of in-hospital complications did not differ between the two groups. CONCLUSIONS: Among patients presenting with new-onset heart failure, a substantial proportion had an ejection fraction of more than 50 percent. The survival of patients with heart failure with preserved ejection fraction was similar to that of patients with reduced ejection fraction. Copyright 2006 Massachusetts Medical Society.

PMID: 16855266 [PubMed - indexed for MEDLINE]

2: Radiology. 2006 Jul;240(1):145-51.

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Statin therapy at carotid angioplasty and stent placement: effect on procedure-related stroke, myocardial infarction, and death.

Groschel K, Ernemann U, Schulz JB, Nagele T, Terborg C, Kastrup A.

Department of Neurology, University of Tubingen, Tubingen, Germany.

PURPOSE: To retrospectively determine if preprocedural statin treatment is associated with a reduction of cardiovascular events after carotid angioplasty and stent placement (CAS) in patients with symptomatic carotid stenosis. MATERIALS AND METHODS: A study resulting in a prospective database was approved by the institutional ethics review board; written informed consent was obtained. The approval and informed consent included future retrospective analysis. Consecutive patients (n = 180) from the prospective database underwent CAS for high-grade symptomatic carotid disease. The frequency of cardiovascular complications (composite of stroke, myocardial infarction, and death within 30 days after CAS) between 127 patients without preprocedural statin treatment and that of 53 patients with preprocedural statin treatment at CAS were compared with chi2 and multivariate logistic regression analysis. RESULTS: The overall 30-day myocardial infarction rate was two of 180 (1%) patients, the minor stroke rate was 16 of 180 (9%) patients, the major stroke rate was one of 180 (0.5%) patients, and the death rate was two of 180 (1%) patients. The incidence of cardiovascular events (composite of stroke, myocardial infarction, and death within 30 days after CAS) was significantly different between patients with preprocedural treatment (4%) and those without preprocedural statin treatment (15%) (P < .05). These higher complication rates among patients without preprocedural statin treatment were not mediated by adjustment for age, sex, other baseline characteristics, degree of carotid stenosis, use of cerebral protection devices, or the year in which CAS was performed. CONCLUSION: Preprocedural statin therapy appears to reduce the incidence of stroke, myocardial infarction, and death within 30 days after CAS. Future prospective randomized trials are warranted to further assess this potential protective effect of statin drugs during carotid interventions. RSNA, 2006

PMID: 16793975 [PubMed - indexed for MEDLINE]

3: J Acquir Immune Defic Syndr. 2006 May;42(1):116-22.

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HIV seroconversion among public sexually transmitted disease clinic patients: analysis of risks to facilitate early identification.

Mehta SD, Ghanem KG, Rompalo AM, Erbelding EJ.

Department of Emergency Medicine, Boston University School of Medicine, Boston, MA 02118, USA. Supriya.Mehta@bmc.org

OBJECTIVES: We identified risks for HIV seroconversion among public sexually transmitted disease (STD) clinic patients. DESIGN: This was a retrospective cohort study conducted January 1993 through October 2002 of STD clinic attendees aged > or =12 years in Baltimore, Maryland. METHODS: A negative HIV enzyme immunoassay (EIA) test was required for staggered cohort entry. Observation time was 30 days to 3 years. The outcome for multivariate Poisson regression was HIV seroconversion (positive EIA and/or Western blot test) compared among patients with or without sexual risk behaviors, drug use, an STD diagnosis, and signs and symptoms at an initial HIV test. RESULTS: One hundred twenty-five HIV seroconversions occurred among 10,535 individuals and 13,693 person-years of observation, for an incidence of 0.91 HIV seroconversions per 100 person-years (95% confidence interval [CI]: 0.76 to 1.09). Median time to HIV seroconversion was 1.54 years (95% CI: 1.11 to 1.73). In multivariate analysis, increased HIV seroconversion risk was associated with older age, drug use, a sexual partner with syphilis or HIV, genital ulcers, and gonorrhea. HIV incidence per 100 person-years was 4.86 for subjects with an HIV-positive sexual partner, 3.06 for those with injection drug use, and 2.40 for those with genital ulcers. CONCLUSIONS: We found a high rate of HIV seroconversion among STD clinic patients with specific risks. Algorithms with HIV RNA testing targeted to patients at the highest risk for seroconversion may optimize prevention and resource utilization.

PMID: 16763500 [PubMed - indexed for MEDLINE]

4: Prog Cardiovasc Nurs. 2006 Spring;21(2):68-75.

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Depression, stress, and blood pressure in urban African-American women.

Artinian NT, Washington OG, Flack JM, Hockman EM, Jen KL.

College of Nursing, Wayne State University, Detroit, MI 48202, USA. n.artinian@wayne.edu

African-American women have disturbingly high rates of hypertension, exceeding those of African-American men and other ethnic groups. Reasons for these disparities are not understood. Depression, more common in women than men, has been linked to endothelial dysfunction, inflammation, metabolic and hematologic abnormalities, and increased sympathetic nervous system activity--all factors associated with cardiovascular disease. A descriptive correlational design was used to test the following hypotheses: 1) African-American women with higher levels of depression will have higher blood pressure (BP) levels, more cardiovascular risk factors, greater stress, and lower social support; and 2) depression will mediate the relationship between stress and BP. A convenience sample of 245 hypertensive African-American women (mean age, 61+/-12.7 years) was recruited through free BP screenings offered in the community. All data were collected during a structured interview and brief physical examination. Pearson r correlation coefficients, analysis of variance, and multiple regression analyses were used to analyze the hypotheses. Women with higher levels of depression had higher diastolic BP and were more likely to smoke, eat fewer fruits and vegetables, and have more stress and less social support. Depression mediated the relationship between stress and diastolic BP. The findings emphasize the importance of assessing both behavioral and psychosocial factors in urban African-American women with hypertension.

PMID: 16760688 [PubMed - indexed for MEDLINE]

5: Am J Trop Med Hyg. 2006 Jun;74(6):999-1007.

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Prevention and treatment strategies used for the community management of childhood fever in Kampala, Uganda.

Kemble SK, Davis JC, Nalugwa T, Njama-Meya D, Hopkins H, Dorsey G, Staedke SG.

Department of Medicine, San Francisco General Hospital, University of California, 94110, USA. Sarah.Kemble@ucsf.edu

To assess malaria-related prevention and treatment strategies in an urban parish of Kampala, Uganda, a questionnaire was administered to 339 randomly selected primary caregivers of children 1-10 years of age. Our study population was relatively stable and well educated, with better access to health services than many in Africa. Ownership of an insecticide-treated net (ITN) was reported by 11% of households and was predicted only by greater household wealth (highest quartile versus lowest quartile: odds ratio [OR] 21.8; 95% confidence interval [CI], 2.74-173). Among women, 5% reported use of an ITN and 11% used intermittent preventive therapy (IPT) during their last pregnancy. Use of appropriate IPT during pregnancy was predicted only by completion of secondary education or higher (OR, 2.87; 95% CI, 1.13-7.21). Children of 123 (36%) caregivers had experienced an episode of fever in the past 2 weeks. Of these, 22% received an anti-malarial that could be considered "adequate" (combination therapy or quinine). Only 1% of febrile children received adequate treatment at the correct dose within 24 hours of onset of fever. The only independent predictor of treatment with an adequate anti-malarial was accessing a clinic or hospital as the first source of care. In this urban area, use of appropriate malaria control measures occurs uncommonly.

PMID: 16760510 [PubMed - indexed for MEDLINE]

6: Clin Orthop Relat Res. 2006 Jun;447:24-7.

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Dislocation of the hip after reimplantation for infection: an analysis of risk factors.

Hartman CW, Garvin KL.

University of Nebraska Medical Center, Department of Orthopaedic Surgery and Rehabilitation, Omaha, NE 68198-1080, USA. cwhartma@unmc.edu

Dislocation is a well documented complication after a two-stage revision arthroplasty for a deep periprosthetic hip infection. We are aware of no reports specifically evaluating the risk factors for dislocation after reimplantation for infection. We hypothesized greater age, increase in the number of operations on the hip, increase in the length of time from resection to reimplantation, greater limb length discrepancy, smaller femoral offset, and using smaller femoral heads would increase the risk of dislocation. We retrospectively reviewed 34 patients who had a two-stage hip revision for periprosthetic infection with a minimum followup of 2 years. Risk factors for dislocation were evaluated. We compared the rate of dislocation in this group to those patients having revision for aseptic failure. Sixteen dislocations occurred in five (14.7%) of 34 patients. Dislocation occurred in three (1.7%) of 171 patients having revision for aseptic failure. In this small series, age at reimplantation, number of previous operations on the hip, length of time from resection to reimplantation, limb length discrepancy, femoral offset, and femoral head size did not seem to be risk factors for dislocation.

PMID: 16741470 [PubMed - indexed for MEDLINE]

7: J Neurosci. 2006 May 31;26(22):6069-76.

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The influence of Alzheimer disease family history and apolipoprotein E epsilon4 on mesial temporal lobe activation.

Johnson SC, Schmitz TW, Trivedi MA, Ries ML, Torgerson BM, Carlsson CM, Asthana S, Hermann BP, Sager MA.

University of Wisconsin-Madison, Wisconsin 53705, USA. scj@medicine.wisc.edu

First-degree family history of sporadic Alzheimer disease (AD) and the apolipoprotein E epsilon4 (APOE4) are risk factors for developing AD. Although the role of APOE4 in AD pathogenesis has been well studied, family history remains a rarely studied and poorly understood risk factor. Both putatively cause early brain changes before symptomatic disease, but the relative contribution of each to brain function is unknown. We examined 68 middle-aged participants with a parent diagnosed with AD [family history (+FH)] and 64 age- and education-matched controls without a first-degree family history of any dementia [no family history (-FH)]. All underwent cognitive testing, APOE genotyping, and a functional magnetic resonance imaging encoding task that required discrimination of novel items from previously learned items. A 2 x 2 factorial ANOVA (presence/absence of parental family history and presence/absence of the APOE4) was used to detect group effects. A greater response to novel items was detected in the mesial temporal lobe and fusiform gyrus bilaterally among persons without a first-degree family history of AD. In hippocampal areas, the -FH +epsilon4 group exhibited the greatest signal change, and the +FH +epsilon4 group exhibited the least. These findings indicate that FH of AD is an important predictor of hippocampal activation during encoding and that FH may modulate the effect of APOE4 in these middle-aged adults, suggesting that an as yet unspecified factor embodied in first-degree family history of AD is influencing the expression of APOE4 on brain function.

PMID: 16738250 [PubMed - indexed for MEDLINE]

8: Circulation. 2006 Jun 6;113(22):2572-8. Epub 2006 May 30.

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Comment in:

· Circulation. 2006 Jun 6;113(22):2566-8.

Aspirin use and outcomes in a community-based cohort of 7352 patients discharged after first hospitalization for heart failure.

McAlister FA, Ghali WA, Gong Y, Fang J, Armstrong PW, Tu JV.

Division of General Internal Medicine, University of Alberta, Edmonton, Canada. Finlay.McAlister@ualberta.ca

BACKGROUND: The safety of aspirin in heart failure (HF) has been called into question, particularly in those patients (1) without coronary disease, (2) with renal dysfunction, or (3) treated with low-dose angiotensin-converting enzyme (ACE) inhibitors and high-dose aspirin. METHODS AND RESULTS: We examined prescription patterns and outcomes (all-cause mortality and/or HF readmission) in patients discharged from 103 Canadian hospitals between April 1999 and March 2001 after a first hospitalization for HF. Of 7352 patients with HF (mean age, 75 years; 44% without coronary disease and 29% with renal dysfunction), 2785 (38%) died or required HF readmission within the first year. Compared with nonusers, aspirin users were no more likely to die or require HF readmission (hazard ratio [HR], 1.02 [0.91 to 1.16]), even in patients without coronary disease (HR, 0.98 [0.78 to 1.22]) or patients with renal dysfunction (HR, 1.13 [0.94 to 1.36]). On the other hand, users of ACE inhibitors were less likely to die or require HF readmission (HR, 0.87 [0.79 to 0.96]), even if they were using aspirin (HR, 0.86 [0.77 to 0.95]). There were no dose-dependent interactions between aspirin and ACE inhibitors. CONCLUSIONS: In this observational study, aspirin use was not associated with an increase in mortality rates or HF readmission rates, and aspirin did not attenuate the benefits of ACE inhibitors, even in patients without coronary disease, patients with renal dysfunction, or patients treated with high-dose aspirin and low-dose ACE inhibitors.

PMID: 16735672 [PubMed - indexed for MEDLINE]

9: Am J Public Health. 2006 Jul;96(7):1300-7. Epub 2006 May 30.

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Access to care, health status, and health disparities in the United States and Canada: results of a cross-national population-based survey.

Lasser KE, Himmelstein DU, Woolhandler S.

Department of Medicine, The Cambridge Health Alliance and Harvard Medical School, Cambridge, Mass, USA. klasser@challiance.org

OBJECTIVES: We compared health status, access to care, and utilization of medical services in the United States and Canada and compared disparities according to race, income, and immigrant status. METHODS: We analyzed population-based data on 3505 Canadian and 5183 US adults from the Joint Canada/US Survey of Health. Controlling for gender, age, income, race, and immigrant status, we used logistic regression to analyze country as a predictor of access to care, quality of care, and satisfaction with care and as a predictor of disparities in these measures. RESULTS: In multivariate analyses, US respondents (compared with Canadians) were less likely to have a regular doctor, more likely to have unmet health needs, and more likely to forgo needed medicines. Disparities on the basis of race, income, and immigrant status were present in both countries but were more extreme in the United States. CONCLUSIONS: United States residents are less able to access care than are Canadians. Universal coverage appears to reduce most disparities in access to care.

PMID: 16735628 [PubMed - indexed for MEDLINE]

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Jul 25 2006 06:31:58

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Jul 25 2006 06:31:58
1: N Engl J Med. 2006 Jul 20;355(3):260-9.	Related Articles, Links

Comment in:

· N Engl J Med. 2006 Jul 20;355(3):308-10.

2: Radiology. 2006 Jul;240(1):145-51.

Related Articles, Links

3: J Acquir Immune Defic Syndr. 2006 May;42(1):116-22.

Related Articles, Links

4: Prog Cardiovasc Nurs. 2006 Spring;21(2):68-75.

Related Articles, Links

5: Am J Trop Med Hyg. 2006 Jun;74(6):999-1007.

Related Articles, Links

6: Lancet Neurol. 2006 Jun;5(6):481-7.

Related Articles, Links

Comment in:

· Lancet Neurol. 2006 Jun;5(6):464-5.

Mortality in adults with newly diagnosed and chronic epilepsy: a retrospective comparative study.

Mohanraj R, Norrie J, Stephen LJ, Kelly K, Hitiris N, Brodie MJ.

Department of Neurology, Royal Preston Hospital, Preston, Lancashire, UK.

BACKGROUND: People with epilepsy are at increased risk of premature death compared with the general population. Many clinicians are unsure whether and when this issue should be broached with their patients. We analysed mortality in patients with newly diagnosed and chronic epilepsy over a 20-year period. METHODS: Patients who attended the epilepsy service at the Western Infirmary in Glasgow, UK between 1981 and 2001, with newly diagnosed epilepsy (n=890) or referred after receiving unsuccessful treatment elsewhere (n=2689) were included in the study. Mortality data were obtained from the General Registrar Office for Scotland. Causes of death were ascertained from death certificates and primary care and health authority records. The two patient cohorts were compared with age-matched and sex-matched Scottish comparison groups. Standardised mortality ratios (SMR) were calculated for each epilepsy type, 10-year age band, and cause of death category. FINDINGS: Newly diagnosed patients had a 42% increase in mortality (SMR 1.42, 95% CI 1.16-1.72) compared with the comparison group. Increased mortality was recorded in those who had not responded to treatment, with no increase in risk observed in patients who were seizure free. In the chronic epilepsy cohort, there was more than double the expected number of deaths (2.05, 1.83-2.26). The incidence of sudden unexpected death in epilepsy was 1.08 and 2.46 per 1000 patient-years in patients with newly diagnosed and chronic epilepsy, respectively. The greatest excess in mortality was reported in patients younger than 30 years. INTERPRETATION: Mortality risks and preventive strategies should be discussed with patients with epilepsy when treatment fails or is refused despite recurrent seizures.

PMID: 16713919 [PubMed - indexed for MEDLINE]

7: SADJ. 2006 Mar;61(2):058-63.

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Dietary intakes and caries experience in children in Limpopo Province, South Africa.

MacIntyre UE, du Plessis JB.

Institute for Human Nutrition, University of Limpopo (Medunsa Campus). umacintyre@medunsa.ac.za

INTRODUCTION: The identification of a rural village with a very low incidence of dental caries among the children provided the opportunity to study the diets of children apparently not exposed to risk factors for dental caries and compare them with children who were at risk. OBJECTIVE: To compare the diet, nutritional status and dental caries experience of 10- and 15-year-olds in an urban town (Malamulele) and a rural village (Mahonisi) in the Limpopo Province, South Africa. METHODS: Dental examinations and anthropometric measurements were done according to standard procedures. Dietary intakes were assessed by four 24-hour recalls. RESULTS: Mean dft/DMFT (decayed and filled deciduous teeth/Decayed, missing and filled permanent teeth) scores were 1.21 and 0.65 for 10- and 15-year-olds in urban Malamulele compared to 0.33 and 0.02 in rural Mahonisi. The percentage caries free in Malamulele was 36% compared to 88% in Mahonisi. The children in Mahonisi were shorter and lighter than those in Malamulele. Estimated fluoride intakes were significantly lower in Malamulele than in Mahonisi (p = 0.01). Mean total added sugar (all sugar not naturally occurring in foods) intake in Malamulele was significantly higher than in Mahonisi (p < 0.05). CONCLUSION: The most significant dietary differences between the two areas were total added sugar and fluoride intakes. The lower added sugar and higher fluoride intake among the rural Mahonisi children contributed to the lower dental caries experience.

PMID: 16711557 [PubMed - indexed for MEDLINE]

8: Emerg Infect Dis. 2006 Apr;12(4):653-60.

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Economic impact of Lyme disease.

Zhang X, Meltzer MI, Pena CA, Hopkins AB, Wroth L, Fix AD.

Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. XZhang4@cdc.gov

To assess the economic impact of Lyme disease (LD), the most common vectorborne inflammatory disease in the United States, cost data were collected in 5 counties of the Maryland Eastern Shore from 1997 to 2000. Patients were divided into 5 diagnosis groups, clinically defined early-stage LD, clinically defined late-stage LD, suspected LD, tick bite, and other related complaints. From 1997 to 2000, the mean per patient direct medical cost of early-stage LD decreased from $1,609 to $464 (p<0.05), and the mean per patient direct medical cost of late-stage LD decreased from $4,240 to $1,380 (p<0.05). The expected median of all costs (direct medical cost, indirect medical cost, nonmedical cost, and productivity loss), aggregated across all diagnosis groups of patients, was approximately $281 per patient. These findings will help assess the economics of current and future prevention and control efforts.

PMID: 16704815 [PubMed - indexed for MEDLINE]

9: J Am Coll Cardiol. 2006 May 16;47(10):2034-41. Epub 2006 Apr 24.

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Racial differences in prevalence of coronary obstructions among men with positive nuclear imaging studies.

Whittle J, Kressin NR, Peterson ED, Orner MB, Glickman M, Mazzella M, Petersen LA.

Primary Care Division, Clement J. Zablocki VA Medical Center, Milwaukee, Wisconsin 53295, USA. jeffrey.whittle@va.gov

OBJECTIVES: The purpose of this research was to compare coronary obstruction between clinically similar African Americans (AA) and white persons undergoing coronary angiography. BACKGROUND: African Americans have higher rates of coronary death than whites, but are less likely to undergo coronary revascularization. Although differences in coronary anatomy do not explain racial difference in revascularization rates, several studies of clinically diverse persons undergoing coronary angiography have found less obstructive coronary disease in AA than clinically similar whites. METHODS: We studied 52 AA and 259 white male veterans who had both a positive nuclear perfusion imaging study and coronary angiography within 90 days of that study in five Department of Veterans Affairs hospitals. We used chart review and patient interview to collect demographics, clinical characteristics, and coronary anatomy results. Before angiography, we asked physicians to estimate the likelihood of coronary obstruction. RESULTS: The treating physicians' estimates of coronary disease likelihood were similar for AA (79.5%) and whites (83.0%); AA were less likely to have any coronary obstruction (63.5% vs. 76.5%, p = 0.05) and had significantly less severe coronary disease (p = 0.01) than whites. African Americans continued to be less likely to have coronary obstruction in analyses controlling for clinical features, including the physician's estimate of the likelihood of coronary obstruction. CONCLUSIONS: These results suggest that AA have less coronary obstruction than apparently clinically similar whites. Further studies are required to confirm our findings and better understand the paradox that AA are less likely to have obstructive coronary disease and more likely to suffer mortality from coronary disease.

PMID: 16697322 [PubMed - indexed for MEDLINE]

10: Med Phys. 2006 Apr;33(4):868-75.

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Reduction of bias and variance for evaluation of computer-aided diagnostic schemes.

Li Q, Doi K.

Department of Radiology, The University of Chicago, Chicago, Illinois 60637, USA. qiangli@uchicago.edu

Computer-aided diagnostic (CAD) schemes have been developed to assist radiologists in detecting various lesions in medical images. In addition to the development, an equally important problem is the reliable evaluation of the performance levels of various CAD schemes. It is good to see that more and more investigators are employing more reliable evaluation methods such as leave-one-out and cross validation, instead of less reliable methods such as resubstitution, for assessing their CAD schemes. However, the common applications of leave-one-out and cross-validation evaluation methods do not necessarily imply that the estimated performance levels are accurate and precise. Pitfalls often occur in the use of leave-one-out and cross-validation evaluation methods, and they lead to unreliable estimation of performance levels. In this study, we first identified a number of typical pitfalls for the evaluation of CAD schemes, and conducted a Monte Carlo simulation experiment for each of the pitfalls to demonstrate quantitatively the extent of bias and/or variance caused by the pitfall. Our experimental results indicate that considerable bias and variance may exist in the estimated performance levels of CAD schemes if one employs various flawed leave-one-out and cross-validation evaluation methods. In addition, for promoting and utilizing a high standard for reliable evaluation of CAD schemes, we attempt to make recommendations, whenever possible, for overcoming these pitfalls. We believe that, with the recommended evaluation methods, we can considerably reduce the bias and variance in the estimated performance levels of CAD schemes.

Publication Types:

· Evaluation Studies

PMID: 16696462 [PubMed - indexed for MEDLINE]

11: J Gastrointestin Liver Dis. 2006 Mar;15(1):21-6.

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Mortality risk factors in chronic pancreatitis.

Seicean A, Tantau M, Grigorescu M, Mocan T, Seicean R, Pop T.

3rd Medical Clinic, University of Medicine and Pharmacy, Str. Croitorilor no. 19-21, 400162 Cluj-Napoca, Romania. andradaseicean@yahoo.com

BACKGROUND: Mortality in chronic pancreatitis is higher than in the general population, the 10-year survival after diagnosis is estimated between 69-80%. AIM: Evaluation of mortality risk factors in chronic pancreatitis. MATERIAL AND METHOD: Eighty-two patients with chronic pancreatitis were followed-up for an average period of 25 months (median 25 months). None of them had an endoscopic treatment before inclusion in this study. The average age of the patients was 48 years (range 29 to 78, median 49), the ratio men:women being 6.5:1. The etiology was alcoholic in 84.2 % cases, pancreas divisum in 8.5% cases and idiopathic in 7.3% of cases. RESULTS: During the follow-up period the mortality rate was 17%, death occurring at on average 59 months (median 53 months) from the onset of the disease. The most frequent causes of death were: pancreatic cancer (3.6%), complications after surgery (3.6%) and upper digestive hemorrhage (2.4%). The mortality risk factors were presence of diabetes, no alleviation of pain under treatment and unceasing of smoking. The type of treatment applied did not influence survival. The cumulative survival rate estimated at 3 years was 80% and at 5 years 59%. CONCLUSIONS: The mortality rate in chronic pancreatitis was higher than those reported in the literature. Death caused by pancreatic cancer occurred in 3.6 % of the patients. There were no cases of death due to extra pancreatic cancers. The mortality risk factors were unceasing of smoking, no alleviation of pain under treatment and presence of diabetes.

PMID: 16680228 [PubMed - indexed for MEDLINE]

12: J Clin Neurosci. 2006 May;13(4):457-65.

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Cognitive status of young and older cigarette smokers: data from the international brain database.

Paul RH, Brickman AM, Cohen RA, Williams LM, Niaura R, Pogun S, Clark CR, Gunstad J, Gordon E.

Centers for Behavioral and Preventive Medicine, Department of Psychiatry, Brown Medical School, Providence, RI 02903, USA. Rpaul@lifespan.org

Previous studies that have examined the impact of cigarette smoking on cognition have revealed mixed results; some studies report no impact and others report detrimental effects, especially in older individuals. Few studies, however, have examined the effects of cigarette smoking on both young and old healthy individuals using highly robust and standardized methods of cognitive assessment. This study draws on an international database to contrast cognitive differences between younger and older individuals who regularly smoke cigarettes and non-smokers. Data were sampled from 1000 highly screened healthy individuals free of medical or psychiatric health complications. A cohort of 62 regular smokers (n = 45 < 45 years of age; n = 1745 years) with a Fagerstrom nicotine dependency score of 1 or more were identified and matched to a cohort of 62 healthy nonsmokers (n = 43 < 45 years; n = 1945 years) on demographic variables and estimated intelligence. Performances on cognitive measures of attention, reaction time, cognitive flexibility, psychomotor speed, and memory were considered for analysis. As a group, smokers performed more poorly than nonsmokers on one measure of executive function. A significant age and smoking status interaction was identified with older smokers performing more poorly than older nonsmokers and younger smokers on a measure of long-delayed recall of new information. Cigarette smoking is associated with isolated and subtle cognitive difficulties among very healthy individuals.

PMID: 16678725 [PubMed - indexed for MEDLINE]

13: Can J Nurs Res. 2006 Mar;38(1):58-80.

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Relationship among employment status, stressful life events, and depression in single mothers.

Samuels-Dennis J.

School of Nursing, University of Western Ontario, London, Canada. jsamuel4@uwo.ca

This purpose of this study was to extend our understanding of employment status as a social determinant of psychological distress among single mothers. A cross-sectional survey assessing stressful life events and depression was completed with 96 single mothers (48 employed and 48 social assistance [SA] recipients) between November 2003 and March 2004. The prevalence of depressive symptoms was significantly higher for the SA recipients. Mild, moderate, and severe depressive symptoms were reported by 2%, 23%, and 67%, respectively, of SA recipients. Total stressful events were markedly greater for SA recipients. In addition, SA recipients reported larger numbers of housing, health, social, and financial stressors. Regression analysis indicated that 40.6% of the variation in depressive symptoms among single mothers was explained by their employment status and stressful events. The findings suggest that women's employment status significantly impacts on their psychological well-being. Implications for nursing practice, policy development, and future research are identified and discussed.

PMID: 16671281 [PubMed - indexed for MEDLINE]

14: J Clin Oncol. 2006 May 1;24(13):2028-37.

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Prognosis after ipsilateral breast tumor recurrence and locoregional recurrences in five National Surgical Adjuvant Breast and Bowel Project node-positive adjuvant breast cancer trials.

Wapnir IL, Anderson SJ, Mamounas EP, Geyer CE Jr, Jeong JH, Tan-Chiu E, Fisher B, Wolmark N.

National Surgical Adjuvant Breast and Bowel Project Operations Office and Biostatistical Center, Pittsburgh, PA, USA. wapnir@stanford.edu

PURPOSE: Locoregional failure after breast-conserving surgery is associated with increased risk of distant disease and death. The magnitude of this risk in patients receiving chemotherapy has not been adequately characterized. PATIENTS AND METHODS: Our study population included 2,669 women randomly assigned onto five National Surgical Adjuvant Breast and Bowel Project node-positive protocols (B-15, B-16, B-18, B-22, and B-25), who were treated with lumpectomy, whole-breast irradiation, and adjuvant systemic therapy. Cumulative incidences of ipsilateral breast tumor recurrence (IBTR) and other locoregional recurrence (oLRR) were calculated. Kaplan-Meier curves were used to estimate distant-disease-free survival (DDFS) and overall survival (OS) after IBTR or oLRR. Cox models were used to model survival using clinical and pathologic factors jointly with IBTR or oLRR as time-varying predictors. RESULTS: Four hundred twenty-four patients (15.9%) experienced locoregional failure; 259 (9.7%) experienced IBTR, and 165 (6.2%) experienced oLRR. The 10-year cumulative incidence of IBTR and oLRR was 8.7% and 6.0%, respectively. Most locoregional failures occurred within 5 years (62.2% for IBTR and 80.6% for oLRR). Age, tumor size, and estrogen receptor status were significantly associated with IBTR. Nodal status and estrogen and progesterone receptor status were significantly associated with oLRR. The 5-year DDFS rates after IBTR and oLRR were 51.4% and 18.8%, respectively. The 5-year OS rates after IBTR and oLRR were 59.9% and 24.1%, respectively. Hazard ratios for mortality associated with IBTR and oLRR were 2.58 (95% CI, 2.11 to 3.15) and 5.85 (95% CI, 4.80 to 7.13), respectively. CONCLUSION: Node-positive breast cancer patients who developed IBTR or oLRR had significantly poorer prognoses than patients who did not experience these events.

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One page.

1: Solid State Nucl Magn Reson. 2005 Sep;28(2-4):111-6. Epub 2005 Jul 26.

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Multiple-quantum NMR spin dynamics of inhomogeneous one-dimensional systems in solids.

Doronin SI, Fel'dman EB.

Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, 142432, Moscow Region, Russia.

Multiple-quantum NMR spin dynamics of inhomogeneous one-dimensional systems in solids is investigated by analytical and numerical methods. A fermion approach for MQ spin dynamics of one-dimensional inhomogeneous systems is developed in the approximation of the dipole-dipole interactions (DDI) of nearest neighbors. It is shown that only MQ coherences of the zeroth and plus/minus second orders appear in the approximation of the DDI of the nearest neighbors even in inhomogeneous one-dimensional systems. We also investigate MQ dynamics of inhomogeneous chains numerically. Intensities of MQ NMR coherences for a linear chain consisting of 3000 spins are calculated.

PMID: 16051472 [PubMed]

2: J Math Biol. 2005 Nov;51(5):557-94. Epub 2005 Jul 13.

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Modelling antibiotic- and anti-quorum sensing treatment of a spatially-structured Pseudomonas aeruginosa population.

Anguige K, King JR, Ward JP.

Division of Theoretical Mechanics, School of Mathematical Sciences, University of Nottingham, Nottingham, NG7 2RD, United Kingdom. keith.anguige@nottingham.ac.uk

The bacterial cell to cell signalling system known as quorum sensing (QS) is essential for the regulation of virulence in many pathogens and offers a specific biochemical target for novel antibacterial therapies. Expanding on earlier work, in which consideration was given to the primary QS system (lasR system) in a homogeneous population of the common human pathogen Pseudomonas aeruginosa, we build a simple spatial model of an early-stage P. aeruginosa biofilm subject to treatment with topically applied anti-QS drugs (of two specific kinds) and conventional antibiotics. In the case of a slowly growing biofilm we show that both kinds of anti-quorum sensing drug are effective in reducing the level of the relevant signal molecule (3-oxo-C12-homoserine lactone; henceforth AHL), in each case obtaining an explicit bound on the steady-state AHL profile in terms of a prescribed surface drug concentration. Using numerical methods, we are also able to reproduce the hysteretic phenomena exhibited by the homogeneous model, in particular showing that for each kind of anti-QS drug there is a parameter regime in which a catastrophic collapse occurs in the steady-state AHL concentration as the surface drug concentration passes some critical value; an alternative way of interpreting this result is to say that, for a prescribed surface drug concentration, there is a critical biofilm depth such that treatment is successful until this depth is reached, but fails thereafter. In the thick-biofilm limit we show that the critical concentration of each drug increases exponentially with the biofilm thickness (or, conversely, that the critical depth increases logarithmically with surface drug concentration); this is dramatically different to the behaviour observed in the corresponding homogeneous model, where the critical concentrations grow linearly with bacterial carrying capacity, and thus highlights the relative difficulty of treating a large, spatially-structured population with diffusing antibacterials.

PMID: 16012802 [PubMed - indexed for MEDLINE]

3: Biomed Eng Online. 2005 Jul 3;4:40.

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A two-dimensional mathematical model of non-linear dual-sorption of percutaneous drug absorption.

George K.

Department of Mathematical Sciences, Brunel University, School of Information Systems, Computing and Mathematics, Uxbridge, Middlesex, UB8 3PH, UK. K.George@swansea.ac.uk

BACKGROUND: Certain drugs, for example scopolamine and timolol, show non-linear kinetic behavior during permeation process. This non-linear kinetic behavior is due to two mechanisms; the first mechanism being a simple dissolution producing mobile and freely diffusible molecules and the second being an adsorption process producing non-mobile molecules that do not participate in the diffusion process. When such a drug is applied on the skin surface, the concentration of the drug accumulated in the skin and the amount of the drug eliminated into the blood vessel depend on the value of a parameter, C, the donor concentration. The present paper studies the effect of the parameter value, C, when the region of the contact of the skin with drug, is a line segment on the skin surface. To confirm that dual-sorption process gives an explanation to non-linear kinetic behavior, the characteristic features that are used in one-dimensional models are (1) prolongation of half-life if the plot of flux versus time are straight lines soon after the vehicle removal, (2) the decrease in half-life with increase in donor concentration. This paper introduces another feature as a characteristic to confirm that dual-sorption model gives an explanation to the non-linear kinetic behavior of the drug. This new feature is "the prolongation of half-life is not a necessary feature if the plots of drug flux versus time is a non-linear curve, soon after the vehicle removal". METHODS: From biological point of view, a drug absorption model is said to be nonlinear if the sorption isotherm is non-linear. When a model is non-linear the relationship between lag-time and donor concentration is non-linear and the lag time decreases with increase in donor concentration. A two-dimensional dual-sorption model is developed for percutaneous absorption of a drug, which shows non-linear kinetic behavior in the permeation process. This model may be used when the diffusion of the drug in the direction parallel to the skin surface must be examined, as well as in the direction into the skin, examined in one-dimensional models. The dual-sorption model is an initial/boundary value problem which consists of (1) one non-linear, two-dimensional, second-order parabolic equation, (2) boundary conditions, (3) one initial condition. Note that, the number of boundary conditions are, six and four, respectively, if the permeation process under consideration is, during the application of the vehicle and during the removal of the vehicle. Adopting the approach of method of lines, the initial/boundary value problem is transformed into an initial-value problem, which consists of (1) a system of non-linear ordinary differential equations, (2) one initial condition. The system of non-linear ordinary differential equations contains time-dependent non-homogeneous terms, if the permeation process under consideration is, during the application of the vehicle. To solve this initial-value problem, an eight-stage sequential algorithm which is second-order accurate, and requires only tri-diagonal solvers, is developed. RESULTS: Simulation of the numerical methods described is carried out with various values of the parameter C. The illustrations are given in the form of figures. The concentration profiles are viewed as parabolas along the mesh lines parallel to x-axis or y-axis. The flow rates in different subregions of the skin-region are studied. The shapes of the concentration profiles are examined before and after the steady-state concentration is reached. The concentration reaches steady-state when the flux reaches the steady state. The plots of flux versus time and cumulative amount of drug eliminated into the receptor cell versus time are given. CONCLUSION: Based on the various values of the parameter, C, conclusions are drawn about (1) flow rate of the drug in different regions of the skin, (2) shape of the concentration profiles, (3) the time required to reach the steady-state value of the concentration, (4) concentration of the drug in different regions of the skin, when steady-state value of the concentration is reached, (5) the time required to reach the steady-state value of the flux, (6) time required to reach the steady-state value of the concentration of the drug, (7) half-life of the concentration of the drug and (8) lag-time. A comparison, between this two-dimensional model and the one-dimensional non-linear dual-sorption model that exists in the literature, is done based on (1) the shape of the concentration profiles at various time levels, (2) the time required to reach the steady-state value of the concentration, (3) lag-time and (4) half-life.

PMID: 15992411 [PubMed - indexed for MEDLINE]

4: Med Eng Phys. 2006 Mar;28(2):156-65. Epub 2005 Jun 6.

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QRS artifact elimination on full night sleep EEG.

Lanquart JP, Dumont M, Linkowski P.

Sleep Laboratory, Department of Psychiatry, Erasme Academic Hospital Free University of Brussels, Belgium. jplanqua@ulb.ac.be

Spectral analysis is now a standard procedure for analyzing the electroencephalograms (EEG) obtained by polysomnographic recordings. These numerical methods assume an artifact-free EEG since artifacts create spurious spectral components. Our aim was the development of a QRS artifact removal technique that might be applied to full night EEG with a minimal human intervention. This technique should handle one EEG channel, with or without use of one ECG channel. Variance minimization, independent component analysis (ICA), morphological filters (MF) have been implemented. Careful attention has been given to define the MF structuring element. The tests on artifact-simulated and real data were checked on the residual ECG spectral components present in the cleaned EEG. The best results are obtained by the MF when the structuring element is an artifact template defined either directly on the EEG or on the ICA ECG component. Further developments are required to identify and subtract the T-wave artifacts.

Publication Types:

· Clinical Trial

PMID: 15939658 [PubMed - indexed for MEDLINE]

5: Phys Med Biol. 2005 Jan 21;50(2):265-80.

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Modelling the transport of ionizing radiation using the finite element method.

Boman E, Tervo J, Vauhkonen M.

Department of Applied Physics, University of Kuopio, Kuopio, Finland.

Radiation therapy treatment planning is based on the calculation of the absorbed dose in the patient domain. For exact dose calculations, the solution of three coupled Boltzmann transport equations (BTEs) is needed to cover the transport of photons, electrons and positrons. In many situations, however, two coupled systems for photons and electrons are enough. The use of numerical methods in finding the exact solution of the unknown particle fluxes is necessary. In the stationary case, the BTE has six variables, three spatial, two directional and one energy variable. In this paper, we describe an approach in which the finite element method (FEM) is used to solve the six-dimensional problem. For the coupled photon-electron system, the variational formulation and the existence and uniqueness of the solution are derived. We simulate the solution of two coupled BTEs describing the travelling of photons and electrons in two spatial dimensions. The results are compared to Monte Carlo calculations with good agreement.

Publication Types:

· Evaluation Studies

· Validation Studies

PMID: 15742943 [PubMed - indexed for MEDLINE]

6: Bioinformatics. 2005 May 15;21(10):2145-60. Epub 2005 Feb 15.

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Prediction methods and databases within chemoinformatics: emphasis on drugs and drug candidates.

Jonsdottir SO, Jorgensen FS, Brunak S.

Center for Biological Sequence Analysis, BioCentrum-DTU, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark. svava@cbs.dtu.dk

MOTIVATION: To gather information about available databases and chemoinformatics methods for prediction of properties relevant to the drug discovery and optimization process. RESULTS: We present an overview of the most important databases with 2-dimensional and 3-dimensional structural information about drugs and drug candidates, and of databases with relevant properties. Access to experimental data and numerical methods for selecting and utilizing these data is crucial for developing accurate predictive in silico models. Many interesting predictive methods for classifying the suitability of chemical compounds as potential drugs, as well as for predicting their physico-chemical and ADMET properties have been proposed in recent years. These methods are discussed, and some possible future directions in this rapidly developing field are described.

Publication Types:

· Review

PMID: 15713739 [PubMed - indexed for MEDLINE]

7: Microcirculation. 2004 Jun;11(4):337-49.

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Impact of the Fahraeus effect on NO and O2 biotransport: a computer model.

Lamkin-Kennard KA, Jaron D, Buerk DG.

School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, Pennsylvania, USA.

Nitric oxide (NO) and oxygen (O2) transport in the microcirculation are coupled in a complex manner, since enzymatic production of NO depends on O2 availability, NO modulates vascular tone and O2 delivery, and tissue O2 consumption is reversibly inhibited by NO. The authors investigated whether NO bioavailability is influenced by the well-known Fahraeus effect, which has been observed for over 70 years. This phenomenon occurs in small-diameter blood vessels, where the tube hematocrit is reduced below systemic hematocrit as a plasma boundary layer forms near the vascular wall when flowing red blood cells (rbcs) migrate toward the center of the bloodstream. Since hemoglobin in the bloodstream is thought to be the primary scavenger of NO in vivo, this might have a significant impact on NO transport. To investigate this possibility, the authors developed a multilayered mathematical model for mass transport in arterioles using finite element numerical methods to simulate coupled NO and O2 transport in the blood vessel lumen, plasma layer, endothelium, vascular wall, and surrounding tissue. The Fahraeus effect was modeled by varying plasma layer thickness while increasing core hematocrit based on conservation of mass. Key findings from this study are that (1) despite an increase in the NO scavenging rate in the core with higher hematocrit, the model predicts enhanced vascular wall and tissue NO bioavailability due to the relatively greater resistance for NO diffusion through the plasma layer; (2) increasing the plasma layer thickness also increases the resistance for O2 diffusion, causing a larger P(O2) gradient near the vascular wall and decreasing tissue O2 availability, although this can be partially offset with inhibition of O2 consumption by higher tissue NO levels; (3) the Fahraeus effect can become very significant in smaller blood vessels (diameters <30 microm); and (4) models that ignore the Fahraeus effect may underestimate NO concentrations in blood and tissue.

PMID: 15280073 [PubMed - indexed for MEDLINE]

8: Annu Rev Biophys Biomol Struct. 2004;33:415-40.

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The thermodynamics of DNA structural motifs.

SantaLucia J Jr, Hicks D.

Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA. jsl@chem.wayne.edu

DNA secondary structure plays an important role in biology, genotyping diagnostics, a variety of molecular biology techniques, in vitro-selected DNA catalysts, nanotechnology, and DNA-based computing. Accurate prediction of DNA secondary structure and hybridization using dynamic programming algorithms requires a database of thermodynamic parameters for several motifs including Watson-Crick base pairs, internal mismatches, terminal mismatches, terminal dangling ends, hairpins, bulges, internal loops, and multibranched loops. To make the database useful for predictions under a variety of salt conditions, empirical equations for monovalent and magnesium dependence of thermodynamics have been developed. Bimolecular hybridization is often inhibited by competing unimolecular folding of a target or probe DNA. Powerful numerical methods have been developed to solve multistate-coupled equilibria in bimolecular and higher-order complexes. This review presents the current parameter set available for making accurate DNA structure predictions and also points to future directions for improvement.

Publication Types:

· Review

PMID: 15139820 [PubMed - indexed for MEDLINE]

9: Bull Math Biol. 2004 May;66(3):539-57.

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Loss of synchronization in partially coupled Hodgkin-Huxley equations.

Labouriau IS, Alves-Pinto C.

Centro de Matematica da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal. islabour@fc.up.pt

We study the loss of synchronization of two partially coupled space-clamped Hodgkin-Huxley equations, with symmetric coupling. This models the coupling of two cells through an electrical synapse. For strong enough coupling it is known that all solutions of the equations approach a state where the two cells are perfectly synchronized, having the same behaviour at each moment. We describe the local bifurcations that arise when the coupling strength is reduced, using a mixture of analytical and numerical methods. We find that perfect synchrony is retained for very small positive values of the coupling strength, for almost all initial conditions. Although perfect synchrony is lost for negative values of the coupling constant, the system always retains some degree of synchronization until it becomes totally unstable. This happens in two ways: in many cases for almost all initial conditions the solutions still approach a perfectly synchronized state. Even when this is not true, the attracting solutions are still synchronized, with a half-period phase shift.

PMID: 15006448 [PubMed - indexed for MEDLINE]

10: Med Biol Eng Comput. 2004 Jan;42(1):61-70.

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Tuned vibration absorber for suppression of rest tremor in Parkinson's disease.

Hashemi SM, Golnaraghi MF, Patla AE.

Department of Mech., Aerospace & Ind. Eng., Ryerson University, Toronto, Canada.

A simple approach for the suppression of the tremor associated with Parkinson's disease is presented. The proposed system is a tuned vibration absorber (TVA), which has been very effective in the suppression of vibrations in an experimental model of the human arm with two degrees of freedom. Theoretical and numerical methods were used to study the behaviour of the arm model and to develop an effective tremor reduction approach. Based on these studies, a vibration absorber was designed, tested numerically and fabricated for experimental testing. Experimental investigations indicated that optimum control performance was related to the position of the controller and the excitation frequency. With a distance of 160 mm from the end of forearm, the TVA was found to have the best performance, and, for different tremor frequencies, the vibration of the experimental model was reduced by more than 80%.

PMID: 14977224 [PubMed - indexed for MEDLINE]

RESEARCH PROPOSALS BIOE 391 November 7, 2006

Keith Prabhal Matthew Rooney

Using real MRI data from MDACC Statistical tests & modeling perfusion. Excellent idea, however, still need to think about specific tests and model types and include solid reference articles- Perhaps a nice review article. Could be published?

Bernard Binder, Tessa Kuykendall Natalia Vasco

Chi Squared analysis, no sources cited - Vague, must find specific BIOE applications. How will you demonstrate the analysis? Especially needs a well written peer reviewed paper as a supporting article.

Albert Yu, Nicolas Ripp, Sarah Wolf, Brian Chek

Heptocellular carcinoma incidence in Sudan related to peanut butter intake and genotype Will perform Chi Squared statistical analysis and compare with publication, cited source. Needs to define risk factor.

Jason Roberts, Daniela Rimer

Linear regression and catheter related infections, refers to a large study. Will relate placement of catheters to infection and develop a model to predict risk of infections. Make sure to probe the limitations of the model.

Wafa Soofi, Allen Chen, Rejgis James Mariko Wei

Oscillatory modelling & Parkinsons Disease, refers to a specific physiological mechanism and potential therapy using mathematical inputs. Has specific reference. May need to spend some time discussing the validity of the approach (physiologically) along with the design considerations.

Stacy Cheng, Frank Ko

Monte Carlo modeling to approximate integrals. Need specific bioengineering example. Find a well written peer reviewed paper as a supporting article. IS the plan to write a MATLAB code and solve a specific problem?

Ketan Shah, Steven Wallace, Naveen Yadav, Shann Yu

Linear, logistic and polynomial regression comparison and using Statin therapy/ Stent publication data set to illustrate statistical methods. Need to make sure that emphasis is on purpose (application) and analysis steps are well described.

Marina Boleda, Neha Kamat, Priyanka Sen

Chi Squared analysis on Epidemiology of depression among fertile and infertile couples in Shiraz. 2 references cited. How large is the study? What is the power of the analysis? Could you compare this study to another population?

Kim Bennett, Amanda Lee, David Jenkinss

Obesity in America, 4 citations of CDC data. Very ambitious study. Can include NHANES if you wish. Need to define specific statistical analysis techniques that will be used. Also need a published review paper. Publishable?

Alex Bryant, Nick Frankel, Andy Miller, Katherine Wu

Modeling of blood flow in the heart using the immersed boundary numerical method. 9 citations, well described physiological application. Will need to provide mathematical background in an educational manner.