154 research outputs found

    De novo draft assembly of the Botrylloides leachii genome provides further insight into tunicate evolution

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    Tunicates are marine invertebrates that compose the closest phylogenetic group to the vertebrates. These chordates present a particularly diverse range of regenerative abilities and life-history strategies. Consequently, tunicates provide an extraordinary perspective into the emergence and diversity of these traits. Here we describe the genome sequencing, annotation and analysis of the Stolidobranchian Botrylloides leachii. We have produced a high-quality 159 Mb assembly, 82% of the predicted 194  Mb genome. Analysing genome size, gene number, repetitive elements, orthologs clustering and gene ontology terms show that B. leachii has a genomic architecture similar to that of most solitary tunicates, while other recently sequenced colonial ascidians have undergone genome expansion. In addition, ortholog clustering has identified groups of candidate genes for the study of colonialism and whole-body regeneration. By analysing the structure and composition of conserved gene linkages, we observed examples of cluster breaks and gene dispersions, suggesting that several lineage-specific genome rearrangements occurred during tunicate evolution. We also found lineage-specific gene gain and loss within conserved cell-signalling pathways. Such examples of genetic changes within conserved cell-signalling pathways commonly associated with regeneration and development that may underlie some of the diverse regenerative abilities observed in tunicates. Overall, these results provide a novel resource for the study of tunicates and of colonial ascidians

    Status of the Endangered Indian Knob Mountainbalm Eriodictyon altissimum (Namaceae) in Central Coastal California

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    Indian Knob Mountainbalm Eriodictyon altissimum (Namaceae) is a shrub endemic to western San Luis Obispo County in central coastal California, and little has been published regarding it. The species was listed as endangered under the California Endangered Species Act in 1979 and the U.S. Endangered Species Act in 1995. At Federal listing in 1995, Indian Knob mountainbalm was known from six occurrences, two of which were in protected areas, with a total population estimate of 2018, Indian Knob mountainbalm is known from seven occurrences, six of which are in protected areas and one (the largest) mostly in a protected area, with a total population count of 6,489+ individuals in 2016. Two occurrences are likely extirpated. Indian Knob mountainbalm is considered a fire-adapted chaparral plant. Reproduction is reported to be primarily vegetative by underground rhizomes, and it is specialized for substrates with physical disturbances, including: steep rocky slopes, cliff faces, fallen rock debris, sand dunes (shifting sand), roadsides, old graded substrates such as dirt/rock roads, the talus of graded substrates, and trails. We report the species grows up to 5.5 m tall and at 98 to 263 m elevation. In consideration of the life history traits used by Anacker et al. (2013) for rare plants in California, Indian Knob mountainbalm would be considered highly vulnerable to climate change. Using the international standards of IUCN, Indian Knob mountainbalm meets the criteria for classification as critically endangered including the following: geographic range, severely fragmented; extent of occurrence, 34 km2 (km2); area of occupancy, 2 (km2); and quality of habitat, continuing to decline (dense vegetation, lack of recent fire). Coordinated conservation and research are needed to further understand the species, and to restore and maintain the five extant occurrences

    Advancing Our Understanding of the Inheritance and Transmission of Pectus Excavatum

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    Pectus excavatum is the most common congenital chest wall abnormality expressed in children, yet its inheritance is poorly understood. Here we present the first comprehensive assessment of the inheritance of this disorder. After evaluating 48 pedigrees and 56 clinical traits of probands and family members, we find strong evidence of autosomal recessive, genetic control for this disorder. Additionally there is likely more than one pectus disease-associated allele, as well as a relatively large number of disease allele carriers in the human population. Some clinical traits appear important and may serve as reliable indicators for predicting the likelihood of pectus excavatum in children before severe symptoms present. Quantifying sex-ratio bias in probands demonstrates a highly significant male bias associated with pectus excavatum. When combined with pedigree data, sex-bias is indicative of sex-linked, sex-limited, and/or epigenetic control such as X-inactivation, reiterating a point made with pedigrees alone, which is that more than one mutation is likely responsible for this disorder

    University students and the risk of HIV and other sexually transmitted infections in Uganda: the Crane survey.

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    Adolescents and young adults are at high risk of human immunodeficiency virus (HIV) infection in sub-Saharan Africa. Previous reports have found that university students in Africa comprise a sexually active population, although the prevalence of HIV or sexually transmitted infections (STI) has not been measured. We conducted a cross-sectional survey of students from five large universities in Kampala, Uganda, using respondent-driven sampling. We asked students to complete behavioral questionnaires and provide biological samples to test for HIV, Chlamydia trachomatis, Neisseria gonorrhoeae, Treponema pallidum, Trichomonas vaginalis, and bacterial vaginosis. We enrolled 649 students and obtained interpretable data from 640. Around 50% of the respondents were male, and the mean age was 22 years. An estimated 0.8% (95% CI 0.0-2.0) of male students had Chlamydia infection, approximately 4.3% (95% CI 2.0-7.0) had syphilis, 0.4% (95% CI 0.0-0.9) had HIV, and none had gonorrhea. An estimated 32.6% (95% CI 22.4-40.8) of women had bacterial vaginosis, 2.5% (95% CI 0.7-6.3) had Chlamydia infection, 1.7% (95% CI 0.5-3.6) had syphilis, 1.0% (95% CI 0.0-2.4) had gonorrhea, 0.9% (95% CI 0.0-4.2) had trichomoniasis, and 0.9% (95% CI 0.0-1.8) had HIV. We found no significant risk factors for HIV or other STI among males. We also found that not using a condom during the latest sexual intercourse was significantly associated with HIV infection, other STI, or bacterial vaginosis (OR 2.16; 95% 1.26-3.78) among females. We conclude that while university students are sexually active and there is substantial risk for syphilis, there is little evidence of substantially increased HIV risk among them

    Fenitrothion: toxicokinetics and toxicologic evaluation in human volunteers.

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    An unblinded crossover study of fenitrothion 0.18 mg/kg/day [36 times the acceptable daily intake (ADI)] and 0.36 mg/kg/day (72 X ADI) administered as two daily divided doses for 4 days in 12 human volunteers was designed and undertaken after results from a pilot study. On days 1 and 4, blood and urine samples were collected for analysis of fenitrothion and its major metabolites, as well as plasma and red blood cell cholinesterase activities, and biochemistry and hematology examination. Pharmacokinetic parameters could only be determined at the higher dosage, as there were insufficient measurable fenitrothion blood levels at the lower dosage and the fenitrooxone metabolite could not be measured. There was a wide range of interindividual variability in blood levels, with peak levels achieved between 1 and 4 hr and a half-life for fenitrothion of 0.8-4.5 hr. Although based on the half-life, steady-state levels should have been achieved; the area under the curve (AUC)(0-12 hr) to AUC(0-(infinity) )ratio of 1:3 suggested accumulation of fenitrothion. There was no significant change in plasma or red blood cell cholinesterase activity with repeated dosing at either dosage level of fenitrothion, and there were no significant abnormalities detected on biochemical or hematologic monitoring
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