Fourth Cohorts Research Articles

Development and piloting of One Health curriculum in Jordan.

In Jordan, several steps have been done to implement One Health (OH) approach. To increase the awareness for OH concept and approach among health professionals, there was an apparent need to develop an OH curriculum or package to orientate human, animal, and environmental health officials and professionals. The aim of this study was to describe the development and piloting of a OH curriculum for human, animal, and environmental officials and professionals in Jordan. OH curriculum was developed and consisted of four chapters/sections, each of which contained series of power point presentations that covered subject thoroughly and met the learning objectives for each section. Four day workshops on OH curriculum were done for four cohorts of participants from different OH partners. Each section started and ended with a quick knowledge assessment consisting of multiple choice questions (MCQs) (pre- and post-chapter). Comparison of the pre- and post-chapter knowledge assessment scores/results were used to assess gain of knowledge after each section of OH curriculum was completed. The scores of correct answers were compared within the different cohorts using Pearson's chi-square test with p-values ≤0.05 considered significant. Of the total attendance, pre- and post- training quizzes were scored for 102 participants (816 quizzes). Pre-training scores for the different cohorts ranged from 29% to 36%, while post-training scores for the different cohorts ranged from 80% to 87%. Post-training correct answers scores were significantly higher than those were for pre-training scores for the different cohorts (p < 0.05). Percentage of knowledge gain ranged from 41% to 62% for the first section, 34% to 47% for the second section, 41% to 55% for the second section, and 48% to 60% for the fourth section. Average percentage of knowledge gain for the first, second, third, and fourth cohorts were 51%, 53%, 47%, and 47%, respectively, and was 50% for all cohorts. The developed OH curriculum improved different OH partners and officials understanding of the OH concept and approach.

Pragmatism's Evolution: Organism and Environment in American Philosophy

Pragmatism's Evolution: Organism and Environment in American Philosophy

Abstract P104: Trends in Population Attributable Fractions of Major Risk Factors for Cardiovascular Disease in Japan, 1975 to 2014: The Circulatory Risk in Communities Study

Introduction: Over the past several decades, Asian countries including Japan have experienced westernization of their lifestyles, leading to changes in prevalence of major risk factors for cardiovascular disease (CVD). The estimation of changed in trends of population attributable fraction (PAF) of major CVD risk factors would be useful for planning of CVD prevention strategies. Hypothesis: We assessed the hypothesis that PAFs of major CVD risk factors have changed among a Japanese population over the past several decades. Methods: We conducted four 10-year cohorts from 1975 to 2014: the baseline of the first cohort as 1975-1977 (n=4,415), that of the second as 1985-1986 (n=7,155), that of the third as 1995-1997 (n=6,892), and that of the fourth as 2005-2007 (n=5,067), consisting of Japanese men and women aged 40-79 years, initially free of CVD, and with valid information on major CVD risk factors (hypertension, diabetes mellitus, hypercholesterolemia, obesity, smoking, alcohol drinking, and atrial fibrilization). Hazard ratios (HRs) and 95 % confidence intervals (95 % CIs) of CVD (incident stroke and ischemic heart disease) risk factors were calculated by Cox proportional hazard model and their PAFs (95 %CIs) were estimated. Results: During the median follow-up of 8.1 years, we documented 227 incident CVDs in the first, 251 in the second, 223 in the third, and 132 in the fourth cohort. The age-adjusted incidence rates per 1,000 person-years of CVD decreased over time; 6.4 in the first, 4.3 in the second, 3.4 in the third, 2.3 in the fourth cohort. Through the four cohorts, hypertension was the leading attributable risk factor for CVD, but its contributions decreased from the first to the fourth cohorts: PAF (95% CI)= 51 (33-64)% in the first; 42 (29-53)% in the second; 47 (32-58)% in the third; and 27 (4-45)% in the fourth cohorts. In contrast, the contributions of diabetes mellitus increased between the third and the fourth cohorts and then diabetes mellitus was promoted to the second leading risk factor: PAF (95% CI)= 1 (-4-6)% in the first; 3 (-1-8)% in the second; 3 (-1-7)% in the third; and 17 (8-25)% in the fourth cohorts. The contributions of hypercholesterolemia and other risk factors were small and did not change over time materially. Similar trends were observed for stroke and coronary heart disease. Conclusions: The contribution of hypertension for CVD risk decreased, while that of diabetes mellitus increased among Japanese over the past 40 years. Taken together with the steep decrease in stroke incidence, decrease in hypertension has contributed to reducing PAF of hypertension, and also resulted in increase in PAF of diabetes. Although hypertension is still the leading attributable risk factor for CVD, diabetes could be another target of CVD prevention strategy among Japanese.

Use of short-acting and long-acting hypnotics and the risk of fracture: a critical analysis of associations in a nationwide cohort

SummaryNumerous observational studies suggest that hypnotics increase the risk of fractures, and long-acting hypnotics are suggested to be especially harmful. This study showed that the highest risk of fracture was found before start of treatment and remained after end of therapy, suggesting that the increased risk during treatment is influenced by other factors, such as underlying disease.IntroductionThe purpose of this study was to evaluate associations between the use of short-acting and long-acting hypnotics and the risk of fracture.MethodsFour cohorts were formed from all individuals living in Sweden aged ≥ 50 years in 2005 (n = 3,341,706). In the first cohort, individuals prescribed long-acting propiomazine (n = 233,609) were matched 1:1 with controls. In the second cohort, individuals prescribed short-acting z-drugs (zopiclone, zolpidem, and zaleplon, n = 591,136) were matched 1:1 with controls. The third and fourth cohorts consisted of full sibling pairs with discordant propiomazine (n = 83,594) and z-drug (n = 153,314) use, respectively.ResultsThe risk of fracture was greatest among users of hypnotics in the 90 days before the initiation of treatment, both for propiomazine (odds ratio [OR], 2.52; 95% confidence interval [CI], 2.28–2.79) and z-drugs (OR, 4.10; 95% CI, 3.86–4.35) compared with that in matched controls. Furthermore, this risk was significantly reduced after the initiation of treatment with propiomazine (OR, 1.42; 95% CI, 1.27–1.60) and z-drugs (OR, 1.67; 95% CI, 1.56–1.80) and remained the first year following the last prescribed dose both for propiomazine (OR, 1.28, 95% CI, 1.21–1.36) and z-drugs (OR, 1.19, 95% CI, 1.16–1.23). The pattern was similar in the sibling cohorts, with the greatest risk of fracture seen in the 90 days before treatment with hypnotics was initiated.ConclusionThe use of short-acting and long-acting hypnotics is associated with an increased risk of fracture. This risk was highest before initiation of treatment and remained after end of therapy. The results suggest that the increased risk during treatment is influenced by other factors such as underlying disease.

Molecular portraits and trastuzumab responsiveness of estrogen receptor-positive, progesterone receptor-positive, and HER2-positive breast cancer.

Background: Estrogen receptor-positive, progesterone receptor-positive, and HER2-positive breast cancers (triple-positive breast cancers, TPBCs) account for 5% to 10% of all breast cancers. The clinical and molecular features of TPBCs remain elusive. In this study, we aim to analyze the multiomics landscape and responsiveness of TPBCs to trastuzumab.Methods: We employed five cohorts. The first cohort was from the Surveillance, Epidemiology, and End Results database (n=32,056) and was used to determine the clinical characteristics of TPBC. The second, third and fourth cohorts were from The Cancer Genome Atlas (n=162), GSE2603 (n=37) and GSE2109 (n=30) datasets, respectively, and were used to examine the genomic features and molecular classification of TPBC. The fifth cohort comprised TPBC patients treated at Fudan University Shanghai Cancer Center (FUSCC, n=171) and was used to investigate an immunohistochemistry-defined luminal A-like subgroup of TPBC.Results: Patients with TPBC had a significantly better prognosis than those with ER-PR-HER2+ breast cancer. Genomic analysis revealed that TPBCs showed a lower TP53 mutation rate (30% vs. 69%, P < 0.001) and lower levels of HER2 mRNA and protein expression than ER-PR-HER2+ breast cancers. More than 40% of TPBCs were classified as the luminal A intrinsic subtype, with an even lower HER2 expression level. Based on the immunohistochemical detection of CDCA8, BCL2 and STC2, we identified a luminal A-like subgroup of TPBCs in the FUSCC cohort (CDCA8-negative, BCL2- and/or STC2-positive). Patients with luminal A-like TPBC had a better prognosis and benefited less from trastuzumab than those with TPBC of other subtypes.Conclusions: TPBCs consist of clinically and genomically heterogeneous subgroups that may require different therapeutic strategies. The luminal A-like subgroup of TPBCs is associated with a better prognosis and reduced benefit from trastuzumab.

Barriers and Facilitators for a Collaborative International Physical Therapist Residency Program in Nairobi, Kenya.

Introduction: With the globalization of higher education through online training, opportunities exist for collaboration between institutions to promote ongoing advancement of healthcare professionals in resource-limited countries. The success of these programs is dependent on the ability of the program to meet the educational needs of the student and assist with implementation of the new information into practice. A post graduate residency program for physical therapists was introduced to Kenya to promote the development of the profession of physical therapy. This study sought to explore barriers that affected participation in the residency program, and how participants perceived the residency program fostered the use of new skills in the clinical environment, as well as the limitations they faced in applying the skills gained through the residency program in a clinical setting.Methods and Materials: The participants in this study were in the third and fourth cohorts of the residency program (n = 27). One-on-one interviews were performed with the residents following completion of the program. A qualitative phenomenology research design was used to describe the manner in which the residency was experienced within the context of the environment in which the experience took place. Descriptions and narratives were obtained from the residents to provide a window into their lived experience.Results: Four themes were discovered: (1) The ongoing challenge to balance often conflicting responsibilities: family, work and education, (2) A need to educate patients and colleagues on newly acquired skills to gain acceptance, (3) Success in the program requires reliance on support networks, and (4) Increased confidence gained in delivery of patient care.Discussion: Although the residents faced obstacles for completing the residency and integrating newly acquired knowledge and skills into clinical practice, they were able to formulate strategies to meet these challenges. Understanding the barriers and facilitators that affect participants in international collaborative efforts may ultimately assist residency and other educational programs in designing new models of education, which will advance the physical therapy profession globally.

Dental Hygiene, Dental, and Medical Students’ OMFS/Hospital Dentistry‐Related Knowledge/Skills, Attitudes, and Behavior: An Exploration

Engaging other health care providers in oral health-related activities and interprofessional care (IPC) could increase access to oral health care for underserved populations in the U.S. The aims of this study were to assess dental hygiene, dental, and medical students' intra- and interprofessional and oral and maxillofacial surgery (OMFS)/hospital dentistry-related knowledge/skills, attitudes, and behavior; determine whether first and second year vs. third and fourth year cohorts' responses differed; and explore how intra- and interprofessional knowledge was related to interprofessional education (IPE) and interprofessional attitudes and behavior. Data were collected between April 2014 and May 2015 from 69 dental hygiene, 316 dental, and 187 medical students. Response rates across classes for the dental hygiene students ranged from 85% to 100%; 24% to 100% for the dental students; and 13% to 35% for the medical students. The results showed that the medical students had lower oral health-related and interprofessional knowledge and less positive attitudes about oral health-related behavior, IPE, and interprofessional teamwork than the dental hygiene and dental students. While third- and fourth-year medical students' interprofessional knowledge/skills and behavior were higher than those of first- and second-year students, the two groups' IPE-related and interprofessional attitudes did not differ. The students' knowledge correlated with their IPE and interprofessional communication-related skills and behavior, but not with their interprofessional attitudes. These dental hygiene, dental, and medical students' OMFS/hospital dentistry-related knowledge/skills and behavior increased over the course of their academic programs, while their IPE-related and intra- and interprofessional attitudes, especially for medical students, did not improve over time. OMFS and hospital dentistry units in medical centers offer distinctive opportunities for IPE and IPC. Utilizing these units may be one way to ensure that graduating providers are motivated to engage in IPC in their practice, thus contributing to reducing oral health disparities and increasing access to oral care for underserved populations.

Molecular essence and endocrine responsiveness of estrogen receptor-negative, progesterone receptor-positive, and HER2-negative breast cancer.

BackgroundThe clinical significance of progesterone receptor (PgR) expression in estrogen receptor-negative (ER–) breast cancer is controversial. Herein, we systemically investigate the clinicopathologic features, molecular essence, and endocrine responsiveness of ER−/PgR+/HER2− phenotype.MethodsFour study cohorts were included. The first and second cohorts were from the Surveillance, Epidemiology, and End Results database (n = 67,932) and Fudan University Shanghai Cancer Center (n = 2,338), respectively, for clinicopathologic and survival analysis. The third and fourth cohorts were from two independent publicly available microarray datasets including 837 operable cases and 483 cases undergoing neoadjuvant chemotherapy, respectively, for clinicopathologic and gene-expression analysis. Characterized genes defining subgroups within the ER–/PgR+/HER2– phenotype were determined and further validated.ResultsClinicopathologic features and survival outcomes of the ER–/PgR+ phenotype fell in between the ER+/PgR+ and ER−/PgR− phenotypes, but were more similar to ER−/PgR−. Among the ER−/PgR+ phenotype, 30 % (95 % confidence interval [CI] 17–42 %, pooled by a fixed-effects method) were luminal-like and 59 % (95 % CI 45–72 %, pooled by a fixed-effects method) were basal-like. We further refined the characterized genes for subtypes within the ER−/PgR+ phenotype and developed an immunohistochemistry-based method that could determine the molecular essence of ER−/PgR+ using three markers, TFF1, CK5, and EGFR. Either PAM50-defined or immunohistochemistry-defined basal-like ER−/PgR+ cases have a lower endocrine therapy sensitivity score compared with luminal-like ER−/PgR+ cases (P <0.0001 by Mann-Whitney test for each study set and P <0.0001 for pooled standardized mean difference in meta-analysis). Immunohistochemistry-defined basal-like ER−/PgR+ cases might not benefit from adjuvant endocrine therapy (log-rank P = 0.61 for sufficient versus insufficient endocrine therapy).ConclusionsThe majority of ER−/PgR+/HER2– phenotype breast cancers are basal-like and associated with a lower endocrine therapy sensitivity score. Additional studies are needed to validate these findings.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-015-0496-z) contains supplementary material, which is available to authorized users.

Dedicated robotics team reduces pre-surgical preparation time

Context:Robot-Assisted Laparoscopic Radical Prostatectomy (RALRP) requires significant preoperative setup time for the room, staff, and surgical platform. The utilization of a dedicated robotics operating room (OR) staff may facilitate efficiency and decrease costs.Aims:We sought to determine the degree to which preoperative time decreased as experience was gained.Materials and Methods:A total of 476 patients with a mean age of 60.2 years were evaluated (11/2006 to 1/2010). Data was assimilated through an institutional review board approved blinded, prospective database. Utilizing time from patient arrival in the OR to robot docking as preoperative preparation, our experience was evaluated. Age, body mass index (BMI), and American Society of Anesthesiologists risk scores (ASA) were compared.Statistical Analysis Used:Analysis of variance; Two-sample t-test for unequal variances.Results:The first and last 100 cases were found to have similar age (P=0.27), BMI (P=0.11), and ASA (P=0.09). The average preoperative times were 66. 4 and 53.4 min, respectively (P<0.05). The second 100 patients treated were found to have a significantly shorter preoperative time when compared to the first 100 patients (P<0.05). When the first 100 cases were divided into cohorts of 10 cases the mean preoperative time for the first through fourth cohorts were 80.5, 69.3, 78.8, and 64.7 min, respectively. After treatment of our first 30 patients we found a significant drop in preoperative time. This persisted throughout the remainder of our experience.Conclusions:From the time of patient arrival a number of tasks are accomplished by the non-physician operating room staff during RALRP. The use of a consistent staff can decrease preoperative setup times and, therefore, the overall length of surgery.

Glutathione-S-transferase (GST) P1, GSTM1, exercise, ozone and asthma incidence in school children

Background:Because asthma has been associated with exercise and ozone exposure, an association likely mediated by oxidative stress, we hypothesised that glutathione-S-transferase (GST)P1, GSTM1, exercise and ozone exposure have interrelated effects...

A genome wide association study of systemic lupus erythematosus (SLE) by SLEGEN, the International SLE Genetics Consortium.

Systemic Lupus Erythematosus (SLE) is a pleomorphic, systemic autoimmune disorder with a strong genetic component (&amp;#955;S~30). The first 720 cases and 2337 controls, all female and self‐reported as European‐derived were divided into two subsets and genotyped at 317,501 markers. The more consistently significant markers were genotyped in third and fourth cohorts of 1739 and 1932 additional European‐derived female subjects for a total of 6728 participants. The most powerful association spans 7.05 mb across the HLA region, where 93 SNPs have p&lt;10‐6 with the minimum p&lt;10–54 at 31.82 mb in the MSH5 gene. Four additional associations are identified in ITGAM, KIAA1542, PXK, an anonymous marker at 1q25, and the known IRF5, all at odds ratios &gt;1.2 and p&lt;10‐7 in the aggregate collection. The results also support STAT4, FCGR2A, and PTPN22 as additional genetic risk factors.

Effects of water depth on survival and growth of Argopecten purpuratus (Lamarck, 1819) spat in northern Chile

Collection and suspended culture of Argopecten purpuratus spat in Japanese-type collectors was undertaken in the Rinconada Marine Reserve (Antofagasta, Chile) to determine growth variations between surface and bottom waters. Scallop spat was collected at 16-m depth and grown at 1- and 16-m depths. An initial settlement of ca. 13,000 post-larvae per bottom collector (2 cohorts) was observed on 3 February 2001. Two new cohorts settled in bottom collectors on 3 March, while no spat settlement occurred in surface collectors. The four cohorts exhibited substantial and different mortality rates over the study period, depending on the cohort and on-growing depth. The first and second cohorts exhibited mortality rates of 80.3 and 53.1% in bottom collectors, respectively, versus 29 and 43.6% in surface structures. The third and fourth cohorts exhibited mortality rates of 21.4 and 59.7% in bottom collectors, respectively. Mean shell height of scallop spat after 88 days of culture was 6.46 mm for the first cohort and 4.37 mm for the second cohort in bottom collectors, versus 10.33 and 7.31 mm in surface collectors, respectively. Mean post-larval growth rate in bottom collectors (86 μm day−1) was significantly lower than growth rate in surface collectors (146 μm day−1). Factors explaining the depth-related mortality and growth rates are discussed to improve scallop culture in the Reserve. It was concluded from the results that culture improvement in Antofagasta Bay would require collecting spat in bottom waters and raising it near the surface during initial cultivation stages.

Gender differences in the causal relation between adolescents' maths self-concept and scholastic performance

Mathematics is a core subject in every school curriculum and it is strongly correlated with maths self-concept, which is defined as the subjective feelings and beliefs about one's competence in maths. In general, boys tend to report higher maths self-concept than girls, but the difference between boys and girls' maths scholastic performance is low or even inexistent. Some authors maintain that academic self-concept can play an important role as a motivational variable, promoting self-confidence and investment in the learning process. This study examined the causal relations between maths self-concept and maths scholastic performance in four cohorts of boys and girls within a three-wave longitudinal study. The first two cohorts were composed of 187 girls and 139 boys attending grades 7 and 8 at Time 1 and the third and fourth cohorts were composed of 167 girls and 123 boys attending grades 9 and 10 at Time 1. Structural Equation Modelling was used to test the fit of several models of causal relations. The results revealed that for the first two cohorts the best models were reciprocal and skill-development for both boys and girls. However, for the older students, a reciprocal model gave a best fit for the boys, but for the girls there was only one significant effect from maths self-concept to maths scholastic performance. Results are discussed on the basis of gender-related differential learning expectancies.

A role of lipin in human obesity and insulin resistance: relation to adipocyte glucose transport and GLUT4 expression

The mouse lipin gene, Lpin1, is important for adipose tissue development and is a candidate gene for insulin resistance. Here, we investigate the adipose tissue expression levels of the human LPIN1 gene in relation to various clinical variables as well as adipocyte function. LPIN1 gene expression was induced at an early step in human preadipocyte differentiation in parallel with peroxisome proliferator-activated receptor gamma. Lipin mRNA levels were higher in fat cells than in adipose tissue segments but showed no difference between subcutaneous and omental depots. Moreover, LPIN1 expression levels were reduced in obesity, improved following weight reduction in obese subjects, and were downregulated in women with the metabolic syndrome. With respect to adipocyte function, adipose LPIN1 gene expression was strongly associated with both basal and insulin-mediated subcutaneous adipocyte glucose transport as well as mRNA levels of glucose transporter 4 (GLUT4). We show that body fat accumulation is a major regulator of human adipose LPIN1 expression and suggest a role of LPIN1 in human preadipocyte as well as mature adipocyte function.

A Phase I evaluation of IFN α-1b in solid tumors, lymphoma or myeloma

2550 Background: Interferon alpha 1 (IFN α-1) has been suggested from prior clinical data to be potentially better tolerated than IFN α-2. The objectives of this trial were to confirm the safety, tolerability and maximum dose of recombinant human IFN α-1b and to measure the effects of IFN α-1b on known IFN induced gene products. Methods: Recombinant human IFN α-1b purified to homogeneity (specific activity 1.0 * 108 units/mg on MDBK cells) was obtained from the Ministry of Public Health in Shanghai. Eligible patients had histologically confirmed metastatic malignancy refractory to standard treatments. Patients were sequentially enrolled to receive increasing doses of IFN α-1b administered by SQ injection daily. Patients were monitored weekly and side effects were graded by the NCI common toxicity criteria. Biologic effects of IFN α-1b were assessed by measuring products of the IFN stimulated genes β2-microglobulin, GTP-cyclohydrolase, ISG 15 and TRAIL at baseline and on days 2, 8 and 29. Seven patients enrolled to the first cohort received 15 μg/m2 of IFN α-1b daily. Six patients were enrolled to the second, third and fourth cohorts and received 45, 135 and 270 μg/m2 respectively. Results: Two grade III toxicities (fatigue and headache) occurred in the first cohort. No grade III toxicities were observed in the second and third cohorts. Grade III fever defined DLT in the fourth cohort. No patients experienced significant weight loss or decline in performance status. No grade IV toxicity related to IFN α-1b occurred in any of the cohorts. One patient with metastatic renal cell cancer treated in the highest dose cohort has had a confirmed partial response. Combined analysis demonstrated significant increases compared to baseline at days 2, 8 and 29 for β2-microglobulin and GTP-cyclohydrolase for all four cohorts (p<0.01). ISG 15 increased significantly over baseline in patients receiving the lowest dose while TRAIL showed significant sustained increases in the three higher dose cohorts (p<0.01). Conclusions: IFN α-1b appears well tolerated clinically and demonstrates differential biologic effects. No significant financial relationships to disclose.

Influence of corn on common waterhemp (Amaranthus rudis) growth and fecundity

Four experiments were conducted in central Iowa during 2001 and 2002 to determine the effects of weed emergence time and corn row spacing on common waterhemp growth and fecundity. Four common waterhemp emergence cohorts were established in each experiment and corresponded to the VE, V3, V5, and V8 stages of corn grown in rows spaced 38 and 76 cm apart. Common waterhemp mortality averaged 20, 56, 97, and 99% for the first, second, third, and fourth cohorts, respectively. Mean mature common waterhemp height for the first cohort was 140 cm, whereas plants emerging at the V8 corn stage were only 5 cm tall. Biomass of the first cohort was 20% less in 38-cm rows than in 76-cm rows, but later cohorts were not affected by row spacing. Biomass and seed production of waterhemp emerging at the V3, V5, and V8 corn stages decreased 80, 97, and 99%, respectively in comparison with the first cohort. Overall results indicate that common waterhemp biomass, survival, and fecundity decline sharply with delayed emergence relative to corn, but weeds emerging at or before the V5 corn stage may still contribute significantly to the seed bank.

Growth of native Hawaiian school children: I. Research design, stature, and weight measurements.

A semilongitudinal survey of the growth of native Hawaiian school children, focused on the development of fatness, has been carried out on the Island of Hawaii. Four cohorts of children, first studied in grades one, four, seven, and ten, were measured annually for four years. Several factors, including percentage of Polynesian ancestry, identification with Hawaiian culture, socioeconomic status, dietary intake, and physical fitness, have been considered for their potential relationship to the development of fatness Data presented here indicate that native Hawaiian boys tend to be taller for their age than NHANES-II medians until age 14 years, but are not significantly taller than their non-Hawaiian classmates. Native Hawaiian boys and girls are heavier for their age than NHANES-II medians at most ages and are significantly heavier than non-Hawaiian classmates. Percentage of Polynesian ancestry is a significant predictor variable of both stature-for-age and weight-for-age among native Hawaiian children in the first and fourth grade cohorts. Study of fatness in a genetically heterogeneous Polynesian population that is relatively homogeneous in regard to modernization may yield insights into genetic contributions to the problem of obesity among Pacific Islanders.

Factors related to persistence among Asian, Black, Hispanic, and White undergraduates at a predominantly white university: Comparison between first and fourth year cohorts

This follow-up study of undergraduate student attrition at Indiana University makes it clear that there exist two different issues: (1) student attrition and the continuing high dropout rates among Blacks, Hispanics, and Native Americans on campus, and (2) the negative quality of campus life for ethnic minorities, including Asians, who have relatively low attrition rates and strong feelings of social alienation and dissatisfaction.

Seasonal changes in components of male and female reproductive success in Raphanus sativus L. (Brassicaceae).

To document seasonal changes in the reproductive behavior of the perfect-flowered, self-incompatible mustard, Raphanus sativus L., we monitored individual survival, flower and fruit production among 58 individuals in a California population over six census dates (cohorts). Population size declined dramatically and mean individual levels of fruit set changed significantly between cohorts. The frequency distribution of flower and fruit production became increasingly skewed over the first four cohorts. The phenotypic maleness of individuals, a standardized measure of phenotypic gender, oscillated during the reproductive season, peaking in the third and fourth cohorts. We calculated a simple estimate of expected male reproductive success of each plant (the number of fruits sired on conspecifics); this estimate was a function of an individual's flower production and the fruit production of its potential mates in our sampled population. Mean expected male success did not differ significantly among cohorts; expected male success per flower did, however, change significantly among cohorts. Among individuals within each cohort, maternal fruit production and expected male success were both positively correlated with flower production throughout the season. Spearman rank correlation coefficients indicate that the strength of these associations, however, changed during the season. Linear regressions of transformed variables indicated that the shape of several fitness functions also changed over time. In addition, the amount of variation in maternal or expected paternal success explained by flower production declined over the first four cohorts. If typical of wild populations, these temporal changes in these functions suggest that measurements of the intensity of phenotypic selection on flower production will depend on when and how fitness is measured in natural populations.