1,020 research outputs found

    Antibody responses to a Cryptosporidium parvum rCP15/60 vaccine

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    Cryptosporidium parvum is a zoonotic apicomplexa-protozoan pathogen that causes gastroenteritis and diarrhoea in mammals worldwide. The organism is transmitted by ingestion of oocysts, which are shed in faeces, and completes its lifecycle in a single host.^1^ C. parvum is ubiquitous on dairy operations worldwide and is one of the leading causes of diarrhoea in calves on these farms.^2,3^ Here, for the first time, we describe the antibody response in a large group of cows to a recombinant C. parvum oocyst surface protein (rCP15/60) vaccine and the antibody response in calves fed rCP15/60-immune colostrum produced by these vaccinated cows. Results of recent genotype surveys indicate that calves are the only major reservoir for C. parvum infections in humans.^4^ Human C. parvum infections are particularly prevalent and often fatal in neonates in developing countries and to immunocompromised people, such as AIDs patients.^4^ Drug therapy against cryptosporidiosis is limited and not wholly efficacious in either humans or calves^5^, making development of an effective vaccine of paramount importance. To date, there is no commercially available effective vaccine against C. parvum, although passive immunization utilizing different zoite surface (glyco)proteins has showed promise.^6-9^ All cows we vaccinated produced an antibody response to the rCP15/60 vaccine and the magnitude of response correlated strongly with the subsequent level of antibody in their colostrum. All calves fed rCP15/60-immune colostrum showed a dose-dependent absorption of antibody. Our results demonstrate that vaccination of cows with rCP15/60 successfully induces antibodies against CP15/60 in their serum and colostrum and that these antibodies are then well absorbed when fed to neonatal calves. With further research, this C. parvum vaccine may well be a practical method of conferring passive protection to calves against cryptosporidiosis. Furthermore, a specifically targeted immune-colostrum may be valuable in protection and treatment of immunocompromised human patients with cryptosporidiosis

    Missouri agriculture : a growing industry, some comparison with the past

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    March 1991"Published by Missouri Agricultural Experiment Station University of Missouri-Columbia in cooperation with Office of Social and Economic Data Analysis University of Missouri System" -- verso t.p

    Faraday-cage-assisted etching of suspended gallium nitride nanostructures

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    We have developed an inductively coupled plasma etching technique using a Faraday cage to create suspended gallium-nitride devices in a single step. The angle of the Faraday cage, gas mix, and chamber condition define the angle of the etch and the cross-sectional profile, which can feature undercut angles of up to 45°. We fabricate singly- and doubly-clamped cantilevers of a triangular cross section and show that they can support single optical modes in the telecom C-band

    Variation resources at UC Santa Cruz

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    The variation resources within the University of California Santa Cruz Genome Browser include polymorphism data drawn from public collections and analyses of these data, along with their display in the context of other genomic annotations. Primary data from dbSNP is included for many organisms, with added information including genomic alleles and orthologous alleles for closely related organisms. Display filtering and coloring is available by variant type, functional class or other annotations. Annotation of potential errors is highlighted and a genomic alignment of the variant's flanking sequence is displayed. HapMap allele frequencies and linkage disequilibrium (LD) are available for each HapMap population, along with non-human primate alleles. The browsing and analysis tools, downloadable data files and links to documentation and other information can be found at

    Chewing, dental morphology and wear in tapirs (Tapirus spp.) and a comparison of free-ranging and captive specimens

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    Feeding practice in herbivorous mammals can impact their dental wear, due to excessive or irregular abrasion. Previous studies indicated that browsing species display more wear when kept in zoos compared to natural habitats. Comparable analyses in tapirs do not exist, as their dental anatomy and chewing kinematics are assumed to prevent the use of macroscopic wear proxies such as mesowear. We aimed at describing tapir chewing, dental anatomy and wear, to develop a system allowing comparison of free-ranging and captive specimens even in the absence of known age. Video analyses suggest that in contrast to other perissodactyls, tapirs have an orthal (and no lateral) chewing movement. Analysing cheek teeth from 74 museum specimens, we quantified dental anatomy, determined the sequence of dental wear along the tooth row, and established several morphometric measures of wear. In doing so, we showcase that tapir maxillary teeth distinctively change their morphology during wear, developing a height differential between less worn buccal and more worn lingual cusps, and that quantitative wear corresponds to the eruption sequence. We demonstrate that mesowear scoring shows a stable signal during initial wear stages but results in a rather high mesowear score compared to other browsing herbivores. Zoo specimens had lesser or equal mesowear scores as specimens from the wild; additionally, for the same level of third molar wear, premolars and other molars of zoo specimens showed similar or less wear compared specimens from the wild. While this might be due to the traditional use of non-roughage diet items in zoo tapirs, these results indicate that in contrast to the situation in other browsers, excessive tooth wear appears to be no relevant concern in ex situ tapir management

    Fast-evolving noncoding sequences in the human genome

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    BACKGROUND: Gene regulation is considered one of the driving forces of evolution. Although protein-coding DNA sequences and RNA genes have been subject to recent evolutionary events in the human lineage, it has been hypothesized that the large phenotypic divergence between humans and chimpanzees has been driven mainly by changes in gene regulation rather than altered protein-coding gene sequences. Comparative analysis of vertebrate genomes has revealed an abundance of evolutionarily conserved but noncoding sequences. These conserved noncoding (CNC) sequences may well harbor critical regulatory variants that have driven recent human evolution. RESULTS: Here we identify 1,356 CNC sequences that appear to have undergone dramatic human-specific changes in selective pressures, at least 15% of which have substitution rates significantly above that expected under neutrality. The 1,356 'accelerated CNC' (ANC) sequences are enriched in recent segmental duplications, suggesting a recent change in selective constraint following duplication. In addition, single nucleotide polymorphisms within ANC sequences have a significant excess of high frequency derived alleles and high F(ST)values relative to controls, indicating that acceleration and positive selection are recent in human populations. Finally, a significant number of single nucleotide polymorphisms within ANC sequences are associated with changes in gene expression. The probability of variation in an ANC sequence being associated with a gene expression phenotype is fivefold higher than variation in a control CNC sequence. CONCLUSION: Our analysis suggests that ANC sequences have until very recently played a role in human evolution, potentially through lineage-specific changes in gene regulation

    Child sexual abuse by different classes and types of perpetrator: Prevalence and trends from an Australian national survey

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    Background Little evidence exists about the prevalence of child sexual abuse (CSA) inflicted by different relational classes of perpetrators (e.g., parents; institutional adults; adolescents), and by individual types of perpetrators (e.g., fathers and male relatives; male teachers and male clergy; known and unknown adolescents). Objective To generate evidence of the prevalence of CSA by different perpetrators, and trends by victim gender and age group. Participants and setting The Australian Child Maltreatment Study collected information about CSA victimisation from a nationally-representative sample of 8503 individuals aged 16 and over. Methods We analysed data about 42 perpetrator types, collapsed into eight classes. We generated national prevalence estimates of CSA inflicted by each perpetrator class and individual perpetrator type, and compared results by victim gender and age group. Results Australian CSA prevalence was 28.5%, with the following prevalence by perpetrator classes: other known adolescents (non-romantic): 10.0%; parents/caregivers in the home: 7.8%; other known adults: 7.5%; unknown adults: 4.9%; adolescents (current/former romantic partners): 2.5%; institutional caregivers: 2.0%; siblings: 1.6%; unknown adolescents: 1.4%. Women experienced more CSA by all perpetrator classes except institutional caregivers. Age group comparison showed significant declines in CSA by parents/caregivers, and other known adults; and increases in CSA by adolescents (current/former romantic partners). Individual perpetrator type comparison showed declines in CSA by fathers, male relatives living in the home, non-resident male relatives, and other known male adults; and increases in CSA by known male adolescents, current boyfriends, and former boyfriends. Conclusions CSA by adults has declined, indicating positive impacts of prevention efforts. However, CSA by adolescents has increased. Further declines in CSA by adults are required and possible. Targeted prevention of CSA by adolescents must be prioritised
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