Use of the EM algorithm to detect QTL affecting multiple-traits in an across half-sib family analysis

QTL detection experiments in livestock species commonly use the half-sib design. Each male is mated to a number of females, each female producing a limited number of progeny. Analysis consists of attempting to detect associations between phenotype and genotype measured on the progeny. When family sizes are limiting experimenters may wish to incorporate as much information as possible into a single analysis. However, combining information across sires is problematic because of incomplete linkage disequilibrium between the markers and the QTL in the population. This study describes formulae for obtaining MLEs via the expectation maximization (EM) algorithm for use in a multiple-trait, multiple-family analysis. A model specifying a QTL with only two alleles, and a common within sire error variance is assumed. Compared to single-family analyses, power can be improved up to fourfold with multi-family analyses. The accuracy and precision of QTL location estimates are also substantially improved. With small family sizes, the multi-family, multi-trait analyses reduce substantially, but not totally remove, biases in QTL effect estimates. In situations where multiple QTL alleles are segregating the multi-family analysis will average out the effects of the different QTL alleles.

Predicting sprint running times from isokinetic and squat lift tests: A regression analysis

This study examined the relationship between isokinetic hip extensor/hip flexor strength, 1-RM squat strength, and sprint running performance for both a sprint-trained and non-sprint-trained group. Eleven male sprinters and 8 male controls volunteered for the study. On the same day subjects ran 20-m sprints from both a stationary start and with a 50-m acceleration distance, completed isokinetic hip extension/flexion exercises at 1.05, 4.74, and 8.42 rad.s(-1), and had their squat strength estimated. Stepwise multiple regression analysis showed that equations for predicting both 20-m maximum velocity nm time and 20-m acceleration time may be calculated with an error of less than 0.05 sec using only isokinetic and squat strength data. However, a single regression equation for predicting both 20-m acceleration and maximum velocity run times from isokinetic or squat tests was not found. The regression analysis indicated that hip flexor strength at all test velocities was a better predictor of sprint running performance than hip extensor strength.

Repeated occurrence of basal cell carcinoma of the skin and multifailure survival analysis: Follow-up data from the nambour skin cancer prevention trial

The aim of this study was to apply multifailure survival methods to analyze time to multiple occurrences of basal cell carcinoma (BCC). Data from 4.5 years of follow-up in a randomized controlled trial, the Nambour Skin Cancer Prevention Trial (1992-1996), to evaluate skin cancer prevention were used to assess the influence of sunscreen application on the time to first BCC and the time to subsequent BCCs. Three different approaches of time to ordered multiple events were applied and compared: the Andersen-Gill, Wei-Lin-Weissfeld, and Prentice-Williams-Peterson models. Robust variance estimation approaches were used for all multifailure survival models. Sunscreen treatment was not associated with time to first occurrence of a BCC (hazard ratio = 1.04, 95% confidence interval: 0.79, 1.45). Time to subsequent BCC tumors using the Andersen-Gill model resulted in a lower estimated hazard among the daily sunscreen application group, although statistical significance was not reached (hazard ratio = 0.82, 95% confidence interval: 0.59, 1.15). Similarly, both the Wei-Lin-Weissfeld marginal-hazards and the Prentice-Williams-Peterson gap-time models revealed trends toward a lower risk of subsequent BCC tumors among the sunscreen intervention group. These results demonstrate the importance of conducting multiple-event analysis for recurring events, as risk factors for a single event may differ from those where repeated events are considered.

Evaluation of multifrequency bioelectrical impedance data for predicting lean tissue mass in beef cattle

Multifrequency bioimpedance analysis has the potential to provide a non-invasive technique for determining body composition in live cattle. A bioimpedance meter developed for use in clinical medicine was adapted and evaluated in 2 experiments using a total of 31 cattle. Prediction equations were obtained for total body water, extracellular body water, intracellular body water, carcass water and carcass protein. There were strong correlations between the results obtained through chemical markers and bioimpedance analysis when determined in cattle that had a wide range of liveweights and conditions. The r(2) values obtained were 0.87 and 0.91 for total body water and extracellular body water respectively. Bioimpedance also correlated with carcass water, measured by chemical analysis (r(2) = 0.72), but less well with carcass protein (r(2) = 0.46). These correlations were improved by inclusion of liveweight and sex as variables in multiple regression analysis. However, the resultant equations were poor predictors of protein and water content in the carcasses of a group of small underfed beef cattle, that had a narrow range of liveweights. In this case, although there was no statistical difference between the predicted and measured values overall, bioimpedance analysis did not detect the differences in carcass protein between the 2 groups that were apparent following chemical analysis. Further work is required to determine the sensitivity of the technique in small underfed cattle, and its potential use in heavier well fed cattle close to slaughter weight.

Regional and total body bone mineral density in elite collegiate male swimmers

Back,ground To examine the role of long-term swimming exercise on regional and total body bone mineral density (BMD) in men. Methods. Experimental design: Cross-sectional. Setting: Musculoskeletal research laboratory at a medical center, Participants:We compared elite collegiate swimmers (n=11) to age-, weight-, and height-matched non-athletic controls (n=11), Measures: BMD (g/cm(2)) of the lumbar spine L2-4, proximal femur (femoral neck, trochanter, Ward's triangle), total body and various subregions of the total body, as well as regional and total body fat and bone mineral-free lean mass (LM) was assessed by dual-energy X-ray absorptiometry (DXA, Hologic QDR 1000/W). Results. Swimmers, who commenced training at 10.7+/-3.7 yrs (mean+/-SD) and trained for 24.7+/-4.2 hrs per week, had a greater amount of LM (p<0.05), lower fat mass (p<0.001) and percent body fat (9.5 vs 16.2 %, p<0.001) than controls. There was no significant difference between groups for regional or total body BRID, In stepwise multiple regression analysis, body weight was a consistent independent predictor of regional and total body BMD, Conclusions. These results suggest that long-term swimming is not an osteogenic mode of training in college-aged males. This supports our previous findings in young female swimmers who displayed no bone mass benefits despite long-standing athletic training.

Placental growth hormone (GH), GH-binding protein, and insulin-like growth factor axis in normal, growth-retarded, and diabetic pregnancies: Correlations with fetal growth

We previously described significant changes in GH-binding protein (GHBP) in pathological human pregnancy. There was a substantial elevation of GHBP in cases of noninsulin-dependent diabetes mellitus and a reduction in insulin-dependent diabetes mellitus. GHBP has the potential to modulate the proportion of free placental GH (PGH) and hence the impact on the maternal GH/insulin-like growth factor I (IGF-I) axis, fetal growth, and maternal glycemic status. The present study was undertaken to investigate the relationship among glycemia, GHBP, and PGH during pregnancy and to assess the impact of GHBP on the concentration of free PGH. We have extended the analysis of specimens to include measurements of GHBP, PGH, IGF-I, IGF-II, IGF-binding protein-1 (IGFBP-1), IGFSP-2, and IGFBP-3 and have related these to maternal characteristics, fetal growth, and glycemia. The simultaneous measurement of GHBP and PGH has for the first time allowed calculation of the free component of PGH and correlation of the free component to indexes of fetal growth and other endocrine markers. PGH, free PGH, IGF-I, and IGF-II were substantially decreased in IUGR at 28-30 weeks gestation (K28) and 36-38 weeks gestation (K36). The mean concentration (+/-SEM) of total PGH increased significantly from K28 to K36 (30.0 +/- 2.2 to 50.7 +/- 6.2 ng/mL; n = 40), as did the concentration of free PGH (23.4 +/- 2.3 to 43.7 +/- 6.0 ng/mL; n = 38). The mean percentage of free PGH was significantly less in IUGR than in normal subjects (67% vs. 79%; P < 0.01). Macrosomia was associated with an increase in these parameters that did not reach statistical significance. Multiple regression analysis revealed that PGH/IGF-I and IGFBP-5 account for 40% of the variance in birth weight. IGFBP-3 showed a significant correlation with IGF-I, IGF-II, and free and total PGK at K28 and K36. Noninsulin-dependent diabetes mellitus patients had a lower mean percentage of free PGH (65%; P < 0.01), and insulin-dependent diabetics had a higher mean percentage of free PGH (87%; P < 0.01) than normal subjects. Mean postprandial glucose at K28 correlated positively with PGH and free PGH (consistent with the hyperglycemic action of GH). GHBP correlated negatively with both postprandial and fasting glucose. Although GHBP correlated negatively with PGH (r = -0.52; P

Family size, economics and child gender preference: A case study in the Nyeri district of Kenya

Kenyan women have more children, especially in rural areas, than in most developing nations. This is widely believed to be an impediment to Kenya’s economic development. Thus, factors influencing family size in the Kenyan context are important for its future. A brief review of economic theories of fertility leads to the conclusion that both economics and social/cultural factors must be considered simultaneously when examining factors that determine the number of children in a family. The need to do this is borne out in Kenya’s situation by utilising responses from a random sample of rural households in the Nyeri district of Kenya. Economic and social/cultural factors intertwine to influence family sizes in this district. After providing a summary of the main statistical results from the survey, we use multiple regression analysis to explore the influences of a woman’s age, level of education, whether she has outside employment, whether the family keeps livestock, whether she expresses a preference for more boys than girls, whether the family uses only family labour (including child labour) and the size of the farm, which is used as a proxy for family income. It was found that preference for male children has an important positive influence on family size in this district. Women were found to have greater preference for male children than their male counterparts possibly because of their fear of being disinherited if they do not produce an heir for their husbands. Preference for sons was also found in allocation of human capital resources at the household level in that the female respondents were found to have lower levels of education than their male counterparts. Various long-term policies are outlined that may help to reduce the number of offspring of women in Kenya.

Corporate stadium sponsorships, signaling theory, agency conflicts, and shareholder wealth

Contrary to the plethora of critical articles recently appearing in both the popular and business press, this carefully controlled investigation of 49 stadium- and arena-naming-rights agreement announcements provides striking evidence that such sponsorships can significantly enhance the stock prices of sponsoring companies. Indeed, the results of the study show that the average stadium sponsor's stock prices increased by 1.65 percent at the time of announcement of the programs-a result considerably in excess of the returns associated with other major marketing programs such as the signing of Olympic sponsorships and celebrity endorsers. A multiple regression analysis employing firm-specific changes in stock prices as the dependent variable and quantifiable corporate and sponsorship-related attributes as independent variables is also presented. Variables positively and significantly correlated with perceived sponsorship success include team-winning percentages, contract length, and high technology and locally based companies. Overall, the findings of the study are consistent with the novel hypothesis that, for some firms, the real value-added of a stadium sponsorship may lie in its ability to serve as an effective or honest signal of managerial confidence in the future of the company.

"Owned by...". Country of origin's new cue

This study identifies and explores a new country of origin (COO) cue, “owned by….” The importance of three extrinsic cues “owned by …,” “made in …” and price was examined using conjoint analysis. Data were collected from a sample of 268 undergraduate students familiar with color televisions. Segments were formed using cluster analysis and analyzed using multiple discriminant analysis. “Owned by …” was found to be important and distinct from the “made in …” cue. Segments based on the two COO cues were identified using importance weights and individual utilities. When segments were formed using individual utilities the individual difference construct, economic nationalism, provided discriminatory power while consumer ethnocentrism did not, supporting the hypothesis that economic nationalism and consumer ethnocentrism differ. Practitioners can now use “owned by …” knowing that it forms an important and distinct marketing tool. Limitations and future research are discussed.

Vitamin A deficiency in poor, urban, lactating women in Bangladesh: factors influencing vitamin A status

Aims: To investigate the prevalence of vitamin A deficiency among lactating women in a poor urban population of Bangladesh, and to examine the relationship between various factors and vitamin A status. Design: Cross-sectional study. Setting: Maternal and child health clinic in Dhaka City, Bangladesh. Subjects and methods: A total of 120 lactating women aged 17-37 years were randomly selected from women who attended a local maternal and child health clinic in Dhaka City for immunisation of their children. Various socio-economic, personal characteristics, dietary intakes of vitamin A and anthropometric data were collected. Serum retinol (vitamin A) concentration was determined as a measure of vitamin A status. Results: Of the subjects, 37% had low serum vitamin A levels (<30 μg dl(-1)), with 13.3% having sub-clinical vitamin A deficiency (<20 mug dl(-1)). Eighty-seven per cent had vitamin A intakes below the recommended dietary allowance. The lactating women who were either illiterate or received only informal education had significantly (P=0.002) lower serum vitamin A levels compared with those who received formal education. The women whose husbands received formal education had significantly (P=0.05) higher serum vitamin A levels than those whose husbands were either illiterate or received only informal education. The serum vitamin A levels of women in households with poor sanitation/latrine practice were significantly (P=0.03) lower than those of women in households with good sanitation/latrine practice. The women with one child had significantly (P=0.015) lower serum vitamin A levels than those with two or more children. Women with a lactation period of 6 months or more had significantly (P=0.034) lower serum vitamin A levels than women with a lactation period of less than 6 months. The women who consumed less than the median vitamin A intake (274.8 mug day(-1)) had significantly (P=0.01) lower serum vitamin A levels than those who consumed more than the median vitamin A intake. By multiple regression analysis, education level of the women, number of living children, duration of lactation and dietary intake of vitamin A were found to have significant independent relationships with serum vitamin A. The overall F-ratio (6.8) was highly significant (P=0.000), the adjusted R-2 was 0.16 (multiple R=0.44). Conclusion: A significant proportion of poor, urban, lactating women in Bangladesh have vitamin A deficiency. Among the various factors, education level of the women, number of living children, duration of lactation and dietary intake of vitamin A appear to be important in influencing the vitamin A status of these women.

Anaemia and vitamin A deficiency in poor urban pregnant women of Bangladesh

This cross-sectional study investigated the prevalence of anaemia and vitamin A deficiency (VAD) among pregnant women in a poor urban population of Bangladesh. It also examined the association of various socio-economic and dietary factors with anaemia and vitamin A status. A maternal and child health clinic in Dhaka city, Bangladesh was used to obtain the sample. Three hundred and eighty three pregnant women, aged 20-30 years, of 20-30 weeks gestation were randomly selected from women on their first presentation for antenatal care. Socio-economic, pregnancy related information, usual dietary pattern, and anthropometric data were collected. Blood haemoglobin and serum retinol (vitamin A) concentrations were determined. About 40% of the pregnant women were anaemic (haemoglobin <11.0 g/dl) and 45% had low serum vitamin A levels (<30 mug/dl); with 8.6% having sub-clinical VAD (serum retinol <20 μg/dl). The women with low serum vitamin A levels had 1.8 times greater risk of being anaemic than did the women with normal vitamin A status. Food frequency data revealed that a large proportion of these women did not consume egg (49%), milk (25%), meat (31%), liver (83%), large fish (32%), small fish (39%) and sweet pumpkin (52%) at all; while about 25% of the women reported consuming dark green leafy vegetables (DGLV) and 64% reported an intake of fruit at least four servings a week. The pregnant women who were either illiterate or received only informal education (up to grade ten) had significantly lower haemoglobin and serum vitamin A levels compared to those who completed at least a secondary school certificate. The women whose husbands were illiterate or received only informal education had significantly (P=0.01) lower serum vitamin A levels than those whose husbands had received at least a secondary school certificate. The women who came from families with a per-capita income below the poverty line had significantly lower haemoglobin and serum vitamin A levels compared to those who came from families with a per-capita income above the poverty line. The women who consumed three servings or less of DGLV and fruit per week had significantly lower haemoglobin and serum vitamin A levels than those who consumed four or more servings a week. The women who never consumed large fish had significantly lower haemoglobin compared to those who reported at least one serving a week. Furthermore, the women who never consumed sweet pumpkin had significantly lower serum vitamin A than the women who ate at least one serving a week. By multiple regression analysis, intake of meat, DGLV and fruit, and serum vitamin A levels were found to have a significant independent relationship with haemoglobin. The overall F-ratio (9.9) was highly significant (P=0.000), the adjusted R-square was 0.086 (multiple R=0.309). Multiple regression analysis for serum vitamin A also revealed a significant independent relationship with per capita income, haemoglobin levels, intakes of DGLV and sweet pumpkin. The overall F-ratio (10.2) was highly significant (P=0.000), the adjusted R-square was 0.10 (multiple R=0.312). In conclusion, anaemia and vitamin A deficiency were highly prevalent among poor urban pregnant women in Bangladesh. Various socio-economic and dietary factors may influence the anaemia and vitamin A status of these women. The present study emphasizes the need for a comprehensive intervention strategy, which include both nutritional and environmental factors, to improve the nutritional status of this population.

Genetic diversity revealed in the apomictic fruit species Garcinia mangostana L. (mangosteen)

The novel molecular marker technique Randomly Amplified DNA Fingerprinting (RAF) was used to survey genetic relationships between 37 accessions of the tropical fruit G. mangostana (mangosteen) and among 11 accessions from eight other Garcinia species. Although mangosteen is believed to reproduce exclusively through apomixis, our results show that considerable genetic diversity exists within G. mangostana and between other Garcinia species. Among the 37 G. mangostana accessions examined, nine different genotypes were identified which clustered into three distinct groups based on correspondence analysis (reciprocal averaging). For 26 (70%) of the accessions no marker variation was detected over 530 loci screened. A further eight (22%) accessions exhibited very low levels of variation (0.2-1%) suggesting at least one well conservedm angosteen genotype. The remaining three accessions (8%) showed extensive variation (22-31%) compared with the majority of accessions. The three mangosteen groups were 63-70% dissimilar to the other Garcinia species investigated. The genetic diversity identified in this research will assist in the conservation of Garcinia germplasm and provides a valuable framework for the genetic improvement of mangosteen.

The NASCAR phenomenon: Auto racing sponsorships and shareholder wealth

This study presents the first analysis of the impact of NASCAR sponsorship announcements on the stock prices of sponsoring firms. The primary finding of the study-that NASCAR sponsorship announcements were accompanied by the largest increases in shareholder wealth ever recorded in the marketing literature in response to a voluntary marketing program-represents a striking and unambiguous stock market endorsement of the sponsorships. Indeed, the 24 sponsors analyzed in this study experienced mean increases in shareholder wealth of over $300 million dollars, net of all of the costs associated with the sponsorships. A multiple regression analysis of firm-specific stock price changes and select corporate and sponsorship attributes indicates that NASCAR sponsorships with more successful racing teams, corporate (as opposed to product or divisional) sponsorships, and sponsorships with direct ties to the consumer automotive industry are all positively correlated with perceived sponsorship success, while corporate cash flow per share (a well-known proxy for agency conflicts within the firm) is negatively related with shareholder approval.

A way forward for land-use planning to achieve policy goals by using spatial modelling scenarios

This paper investigates how demographic (socioeconomic) and land-use (physical and environmental) data can be integrated within a decision support framework to formulate and evaluate land-use planning scenarios. A case-study approach is undertaken with land-use planning scenarios for a rapidly growing coastal area in Australia, the Shire of Hervey Bay. The town and surrounding area require careful planning of the future urban growth between competing land uses. Three potential urban growth scenarios are put forth to address this issue. Scenario A ('continued growth') is based on existing socioeconomic trends. Scenario B ('maximising rates base') is derived using optimisation modelling of land-valuation data. Scenario C ('sustainable development') is derived using a number of social, economic, and environmental factors and assigning weightings of importance to each factor using a multiple criteria analysis approach. The land-use planning scenarios are presented through the use of maps and tables within a geographical information system, which delineate future possible land-use allocations up until 2021. The planning scenarios are evaluated by using a goal-achievement matrix approach. The matrix is constructed with a number of criteria derived from key policy objectives outlined in the regional growth management framework and town planning schemes. The authors of this paper examine the final efficiency scores calculated for each of the three planning scenarios and discuss the advantages and disadvantages of the three land-use modelling approaches used to formulate the final scenarios.

Cadmium-induced nephropathy in the development of high blood pressure

In recognition of a central role of the kidney in long-term blood pressure control, we undertook an in-depth analysis of the relationship between blood pressure and kidney damage caused by environmental exposure to the common pollutants cadmium and lead. The subjects were 200 healthy Thais, 16 and 60 years of age (100 female non-smokers, 53 male non-smokers, and 47 male smokers). None of these subjects had been exposed to Cd or Pb in the workplace and their urinary Cd concentrations ranged from 0.4 to 37 nM, whereas their urinary Pb concentrations ranged from 0.1 to 30 nM. The prevalence of high blood pressure was 2%, 8% and 19%, respectively in subjects with low, average and high Cd-burden (linear trend chi(2) = 6.4, P = 0.01). Multiple regression analysis revealed a significant positive association between Cd-burden and blood pressure in male nonsmokers (adjusted beta = 0.31, P = 0.02) and an inverse association between blood pressure and urinary Pb excretion rate in male smokers (adjusted beta = -0.38, P = 0.005). Associations between Cd-burden and nephropathies were evidenced by increases in urinary excretion of beta 2-microglobutin (P = 0.02) and N-acetyl-beta-D-glucosaminidase (P = 0.005) in subjects with high Cd-burden, compared with the subjects with average Cd-burden. In addition, an association between Cd-related nephropathy and high blood pressure was evidenced by a 20% increase in the prevalence of high blood pressure in people with NAG-uria (linear trend chi(2) = 4.3, P = 0.04). Our present study provides first evidence for a possible link between renal tubular damage and dysfunction caused by environmental Cd exposure and increased risk of high blood pressure. (c) 2005 Elsevier Ireland Ltd. All rights reserved.