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A new species of Pythiumisolated from soybean in Ohio is described. Pythium delawariisp. nov. is characterized by globose internally proliferating sporangia, aplerotic oospores and diclinous antheridia that make broad lengthwise contact. Sporangia produce conspicuous papilla and germinate indirectly by producing zoospores via a vesicle and proliferate internally or the sporangia germinate directly with either one or more germ tubes. Pythium delawariiis pathogenic on soybean causing damping-off of seedlings. This oomycete can grow at 10–34 C with an optimum of 28 C. The sequence of the ITS1, 5.8S and ITS2 region of the rDNA did not match the sequence of any known Pythiumspecies but was similar to P. citrinum, P. litoraleand P. sterilum. P. delawariican be distinguished from these three species based on the presence of aplerotic oospores and diclinous antheridia and the absence of hypogynous antheridia. Therefore biological, morphological and molecular data support the recognition of a new species.

Gray leaf spot (GLS) of maize (Zea maysL.) caused by Cercospora zeae‐maydisTehon & E.Y. Daniels, can greatly reduce grain yield in conducive environments worldwide. This study was undertaken to evaluate a novel source of resistance to C. zeae‐maydisacross macroenvironments and link molecular markers to resistance loci by selective genotyping. A population of 144 F2:3progeny lines derived from a cross between resistant maize inbred VO613Y and susceptible inbred Pa405 were evaluated at Wooster, OH, USA, and Cedara Agricultural Research Institute, Department of Agriculture, KZN, Republic of South Africa (RSA), for resistance to C. zeae‐maydisThe lines were assigned to phenotypic classes (resistant, intermediate, and susceptible) on the basis of percent leaf area affected (PLAA) values across environments. F2:4progeny lines were produced by controlled self‐pollination of an individual plant within each F2:3line. F2:4lines derived from resistant and susceptible classes were evaluated at two Ohio locations. The same lines, plus a random sample of 54 F2:4lines representing the intermediate class, were evaluated at Cedara. Molecular marker data were analyzed on the basis of PLAA means of F2:4progenies by Kruskal–Wallis analysis and several markers on chromosomes 2 and 4 were deemed to be significantly associated with resistance. Additional molecular markers were added and composite interval mapping was conducted on genetic maps of those chromosomes. Quantitative trait loci (QTL) located on chromosome arms 2L and 4L together explained 40 to 47% of the phenotypic variation. A resistance gene analog probe flanked the significant interval on chromosome 4L. These intervals on chromosomes 2L and 4L were detected in all tests and we consider them to be suitable candidate QTL for marker‐assisted selection (MAS). These results indicate that VO613Y is a source of resistance with potential to be deployed effectively in both southern Africa and the U.S. Corn Belt.

The spread of grey leaf spot caused by Cercospora zeae-maydisfrom infested maize residue on the soil surface and progress over time were studied under tropical conditions at two locations in central Uganda, Kabanyolo and Namulonge, using a susceptible local cultivar, LP16. Infested maize residue collected the previous season was used as the inoculum source in varying amounts; 80 coverage, 40 coverage and 0 soil coverage were used to simulate no tillage, minimum tillage and maximum tillage with complete burial of residues. In all the seasons, disease spread was adequately described by a power law model, whereas disease progress over time was equally well represented by both Gompertz and logistic models. The time factor was highly significant (P< 0.05) for disease development, indicating both increases in disease intensity over time and change in gradients with time. The amount of infested residue on the soil surface in the maize planting was highly significant (P< 0.05) for slope (b) and intercept (a) of the linearised disease gradient. The gradient parameter (b) based on the average for the four directions from the residue source ranged from ?0.96 to ?0.08 in the second cropping season of 1999, from ?2.16 to ?0.01 and from ?0.87 to ?0.03 in the first and second seasons of 2000, respectively. The distance from the infested residue significantly affected foliar disease, but the direction from the residue inoculum source did not, nor was the distance by direction interaction significant. However, interactions between amount of residue and distance were significant. Percentage leaf area affected by grey leaf spot, the areas under disease progress curves and disease intercepts decreased with distance at both locations, but rate of disease increase (r) was generally constant with distance from residue source at Kabanyolo, but not at Namulonge. The relationship between disease severity and amount of residue cover appeared to be affected by the level of background inoculum. At Kabanyolo, where little background inoculum was present, differences were detected in disease severity parameters between the no-residue plots and residue plots, whereas at Namulonge, where high background levels existed, there was no effect of residue on disease.

A recent cohort mortality study of male, hourly wage employees of a large Michigan chemical production and research facility had found a greater than expected number of deaths coded to liver and biliary tract cancer. In response, an additional investigation was then undertaken of the 44 liver and biliary tract cancer deaths observed between 1940 and 1982. A random sample (N = 1,888) of subjects was selected from the total cohort (N = 21,437) to serve as referents. Company work history records were used to classify cases and referents by work area assignment and potential for exposure to 11 selected chemical agents which have been shown to produce cancer of the liver or biliary passages in experimental animals. Statistically significant associations in both positive and negative directions were found for several work areas within the facility. A suggestive association was found for vinyl chloride monomer, based on five cases with presumed exposure.

Nonparticipants in general population health surveys have been found to be less healthy than participants, but data on nonparticipants in work-site health surveys have been more scarce. We compared cause-specific mortality among 11 156 male employees of The Dow Chemical Company who participated in at least one work-site health examination between 1967 and 1978 with 6915 employees who did not participate. The nonparticipants experienced higher mortality rates for nearly every cause of death examined but particularly from smoking and alcohol-abuse related diseases. This was especially true during the first 5 years of follow-up, suggesting that some employees do not participate because they are already ill. These findings have important implications for the use of examination data for both primary and secondary disease prevention purposes, and these are discussed.

Recognizing the importance of early detection of breast cancer, the Dow Chemical Company initiated a breast cancer awareness program in 1988. Evaluation of operational aspects of mammography screening component revealed that about half (53) of 1186 eligible women in the evaluation cohort took part, although participation was three times higher for active than for retired employees. Eleven per cent of participants were considered to have “positive” screens, ie, had roentgenogram films with suspicious areas, and at least 82 of these women had follow-up medical services within 1 year of screening, as determined by a review of group insurance claims records. Two women with positive mammograms were subsequently diagnosed and treated for breast cancer within 2 months of screening. None of the women with negative mammograms developed breast cancer in the subsequent year. The suitability of group insurance data resources for responding to health care delivery questions is discussed.

Objective: This objective of this study is to examine the association between suicidal behaviour and substance use, depression, aggressiveness and borderline personality traits among adolescents from Sincelejo, a rural city in the north of Colombia.