Anatomy, morphology and evolution of the patella in squamate lizards and tuatara (Sphenodon punctatus)

The patella (kneecap) is the largest and best-known of the sesamoid bones, postulated to confer biomechanical advantages including increasing joint leverage and reinforcing the tendon against compression. It has evolved several times independently in amniotes, but despite apparently widespread occurrence in lizards, the patella remains poorly characterised in this group and is, as yet, completely undescribed in their nearest extant relative Sphenodon (Rhynchocephalia). Through radiography, osteological and fossil studies we examined patellar presence in diverse lizard and lepidosauromorph taxa, and using computed tomography, dissection and histology we investigated in greater depth the anatomy and morphology of the patella in 16 lizard species and 19 Sphenodon specimens. We have found the first unambiguous evidence of a mineralised patella in Sphenodon, which appears similar to the patella of lizards and shares several gross and microscopic anatomical features. Although there may be a common mature morphology, the squamate patella exhibits a great deal of variability in development (whether from a cartilage anlage or not, and in the number of mineralised centres) and composition (bone, mineralised cartilage or fibrotendinous tissue). Unlike in mammals and birds, the patella in certain lizards and Sphenodon appears to be a polymorphic trait. We have also explored the evolution of the patella through ancestral state reconstruction, finding that the patella is ancestral for lizards and possibly Lepidosauria as a whole. Clear evidence of the patella in rhynchocephalian or stem lepidosaurian fossil taxa would clarify the evolutionary origin(s) of the patella, but due to the small size of this bone and the opportunity for degradation or loss we could not definitively conclude presence or absence in the fossils examined. The pattern of evolution in lepidosaurs is unclear but our data suggest that the emergence of this sesamoid may be related to the evolution of secondary ossification centres and/or changes in knee joint conformation, where enhancement of extensor muscle leverage would be more beneficial.Sophie Regnault, Marc E. H. Jones, Andrew A. Pitsillides, John R. Hutchinso

Proceedings of the Salford Postgraduate Annual Research Conference (SPARC) 2011

These proceedings bring together a selection of papers from the 2011 Salford Postgraduate Annual Research Conference(SPARC). It includes papers from PhD students in the arts and social sciences, business, computing, science and engineering, education, environment, built environment and health sciences. Contributions from Salford researchers are published here alongside papers from students at the Universities of Anglia Ruskin, Birmingham City, Chester,De Montfort, Exeter, Leeds, Liverpool, Liverpool John Moores and Manchester

Predicting Distribution of Aedes Aegypti and Culex Pipiens Complex, Potential Vectors of Rift Valley Fever Virus in Relation to Disease Epidemics in East Africa.

The East African region has experienced several Rift Valley fever (RVF) outbreaks since the 1930s. The objective of this study was to identify distributions of potential disease vectors in relation to disease epidemics. Understanding disease vector potential distributions is a major concern for disease transmission dynamics. DIVERSE ECOLOGICAL NICHE MODELLING TECHNIQUES HAVE BEEN DEVELOPED FOR THIS PURPOSE: we present a maximum entropy (Maxent) approach for estimating distributions of potential RVF vectors in un-sampled areas in East Africa. We modelled the distribution of two species of mosquitoes (Aedes aegypti and Culex pipiens complex) responsible for potential maintenance and amplification of the virus, respectively. Predicted distributions of environmentally suitable areas in East Africa were based on the presence-only occurrence data derived from our entomological study in Ngorongoro District in northern Tanzania. Our model predicted potential suitable areas with high success rates of 90.9% for A. aegypti and 91.6% for C. pipiens complex. Model performance was statistically significantly better than random for both species. Most suitable sites for the two vectors were predicted in central and northwestern Tanzania with previous disease epidemics. Other important risk areas include western Lake Victoria, northern parts of Lake Malawi, and the Rift Valley region of Kenya. Findings from this study show distributions of vectors had biological and epidemiological significance in relation to disease outbreak hotspots, and hence provide guidance for the selection of sampling areas for RVF vectors during inter-epidemic periods

MTN-001: Randomized Pharmacokinetic Cross-Over Study Comparing Tenofovir Vaginal Gel and Oral Tablets in Vaginal Tissue and Other Compartments

Background: Oral and vaginal preparations of tenofovir as pre-exposure prophylaxis (PrEP) for human immunodeficiency virus (HIV) infection have demonstrated variable efficacy in men and women prompting assessment of variation in drug concentration as an explanation. Knowledge of tenofovir concentration and its active form, tenofovir diphosphate, at the putative vaginal and rectal site of action and its relationship to concentrations at multiple other anatomic locations may provide key information for both interpreting PrEP study outcomes and planning future PrEP drug development. Objective: MTN-001 was designed to directly compare oral to vaginal steady-state tenofovir pharmacokinetics in blood, vaginal tissue, and vaginal and rectal fluid in a paired cross-over design. Methods and Findings: We enrolled 144 HIV-uninfected women at 4 US and 3 African clinical research sites in an open label, 3-period crossover study of three different daily tenofovir regimens, each for 6 weeks (oral 300 mg tenofovir disoproxil fumarate, vaginal 1% tenofovir gel [40 mg], or both). Serum concentrations after vaginal dosing were 56-fold lower than after oral dosing (p<0.001). Vaginal tissue tenofovir diphosphate was quantifiable in ≥90% of women with vaginal dosing and only 19% of women with oral dosing. Vaginal tissue tenofovir diphosphate was ≥130-fold higher with vaginal compared to oral dosing (p<0.001). Rectal fluid tenofovir concentrations in vaginal dosing periods were higher than concentrations measured in the oral only dosing period (p<0.03). Conclusions: Compared to oral dosing, vaginal dosing achieved much lower serum concentrations and much higher vaginal tissue concentrations. Even allowing for 100-fold concentration differences due to poor adherence or less frequent prescribed dosing, vaginal dosing of tenofovir should provide higher active site concentrations and theoretically greater PrEP efficacy than oral dosing; randomized topical dosing PrEP trials to the contrary indicates that factors beyond tenofovir's antiviral effect substantially influence PrEP efficacy. Trial Registration: ClinicalTrials.gov NCT00592124

Large introns in relation to alternative splicing and gene evolution: a case study of Drosophila bruno-3

Background: Alternative splicing (AS) of maturing mRNA can generate structurally and functionally distinct transcripts from the same gene. Recent bioinformatic analyses of available genome databases inferred a positive correlation between intron length and AS. To study the interplay between intron length and AS empirically and in more detail, we analyzed the diversity of alternatively spliced transcripts (ASTs) in the Drosophila RNA-binding Bruno-3 (Bru-3) gene. This gene was known to encode thirteen exons separated by introns of diverse sizes, ranging from 71 to 41,973 nucleotides in D. melanogaster. Although Bru-3's structure is expected to be conducive to AS, only two ASTs of this gene were previously described. Results: Cloning of RT-PCR products of the entire ORF from four species representing three diverged Drosophila lineages provided an evolutionary perspective, high sensitivity, and long-range contiguity of splice choices currently unattainable by high-throughput methods. Consequently, we identified three new exons, a new exon fragment and thirty-three previously unknown ASTs of Bru-3. All exon-skipping events in the gene were mapped to the exons surrounded by introns of at least 800 nucleotides, whereas exons split by introns of less than 250 nucleotides were always spliced contiguously in mRNA. Cases of exon loss and creation during Bru-3 evolution in Drosophila were also localized within large introns. Notably, we identified a true de novo exon gain: exon 8 was created along the lineage of the obscura group from intronic sequence between cryptic splice sites conserved among all Drosophila species surveyed. Exon 8 was included in mature mRNA by the species representing all the major branches of the obscura group. To our knowledge, the origin of exon 8 is the first documented case of exonization of intronic sequence outside vertebrates. Conclusion: We found that large introns can promote AS via exon-skipping and exon turnover during evolution likely due to frequent errors in their removal from maturing mRNA. Large introns could be a reservoir of genetic diversity, because they have a greater number of mutable sites than short introns. Taken together, gene structure can constrain and/or promote gene evolution

Halotolerant streptomycetes isolated from soil at Taif region, Kingdom of Saudi Arabia (KSA) I: Purification, salt tolerance range, biological and molecular identification

This study focuses on isolation and purification of some halotolerant streptomycetes from soil and sea water of western region, KSA as a source of salt tolerance gene(s). A few numbers (32) of streptomycetes-like colonies (SLC) were isolated and purified from two regions. From Jeddah, a number of 22 out of the 32 SLC were obtained, distributed between the sea water 12 (54.55%) and sea sediment soil 6 (27.27%).From Taif-soil, only 10 SLC were isolated. Results show that 31 SLC were grown on 3.5% salt, while, in the presence of 7.0% salt, 2, 3, 18, and 4 showed abundant (+++), moderate (++), weak (+), and in doubt (±) growth, respectively. Only five SLC were not able to grow at 7% salt. At the level of 10.5% salt, the number of SLC was decreased up to 4 (2 (+++), 1 (++) and 1(+)). In either 14% or 21% salt, four isolates were varied in their ability in growth as moderate or weak growth was recorded. These isolates were considered as halotolerant as they were able to grow in either the presence or normal growth medium. The four isolates which tolerate 14% salt (isolates 4 and 6) and 21% salt (isolates 2 and 8) were completely identified. The streptomycete isolate 2 appeared to be related to Streptomyces cirratus. Comparing the cultural, morphological and physiological characteristics of Streptomyces isolate 4 and 6, they were very likely to be strains of S. rishiriensis and S. alboflavus, respectively. Streptomyces isolate 8 was identified as a strain of S. luteogriseus. The nucleotide sequences of 16S rRNA gene was partially determined using the DNA template of the Streptomyces isolate 8. Results show that a final sequence of about 1462 nts was obtained and compared with eight universal Streptomyces and bacterial strains. This isolate could be classified as a new species of gray Streptomyces, and it was suggested to be named a new halotolerant Streptomyces sp. TSA-KSA strain (GenBank AB731746).Keywords: Streptomyces, halotolerant, identification, 16S rRNA, Taif, Kingdom of Saudi Arabia (KSA)African Journal of Biotechnology Vol. 12(19), pp. 2565-257

Molecular studies on some soil-Streptomyces strains of western region, Kingdom of Saudi Arabia (KSA)

Random amplified polymorphic of DNA-polymerase chain reaction (RAPD-PCR) analysis of the DNA extracted from seven Streptomyces strains of western region, KSA was the aim of this study. Partial sequence of 16S rRNA gene of Streptomyces polychromogenes was also attempted. Results show that a total number of 240 amplified fragments were amplified using 10 RAPD-PCR primers (OPA11, OPB10, OPB15, OPC03, OPC07, OPC18, OPD05, OPE05, OPO14 and OPO17). A total number of 97, 73, 88, 79, 100, 108 and 82 fragments were amplified from the DNA extracts of S. polychromogenes, Streptomyces chattanoogensis, Streptomyces lucensis, Streptomyces antibioticus, Streptomyces violans, Streptomyces griseorubiginosus and Streptomyces violaceus, respectively. An obvious variation in the amplified fragments was recorded using the 10 RAPD-PCR primers (31, 27, 17, 19, 23, 29, 24, 26, 23 and 21 fragments for the primers, respectively). The highest similarity (66.7%) was found between S. lucensis and S. chattanoogensis; lowest similarity (35%) was recorded between the gray S. chattanoogensis and the red S. violaceus. The 16S rRNA gene was isolated via PCR from the DNA of S. polychromogenes (1) and sequenced. Fragments of 1003 and 837 nts were amplified using the forward and reverse primers, respectively. On matching, a final sequence of about 1452 nts (GenBank: JQ962978.1) was obtained and compared with five universal Streptomyces strains and four bacterial clones. The percent identities between the isolate of this study and the compared bacterial strains was lowest (79.1%) compared to HQ844464.1 and highest (98.3%) compared to EU520331.1. Based on the phenotypic and genotypic (16S rRNA gene) features, the strain could be classified as a new strain of S. polychromogenes.Keywords: Identification, Streptomyces, RAPD-PCR, 16S rRNA gene, KSAAfrican Journal of Biotechnology Vol. 12(19), pp. 2558-256

Halotolerant streptomycetes isolated from soil at Taif region, Kingdom of Saudi Arabia II: RAPD-PCR analysis and salt tolerance-gene isolation

The genus Streptomyces is represented in nature by the largest number of species and varieties among the family Streptomycetaceae. This study aimed at extracting the DNA of four halotolerant Streptomyces strains followed by determination of DNA fingerprinting of them using a molecular tool. A trail to isolate salt tolerance gene(s) from their DNA was also aimed. RAPD-PCR technique was applied using seven RAPD-PCR primers. Results show that a total 71 fragments (65 polymorphic and six monomorphic) were amplified from the DNA of the four identified Streptomyces strains. The fragments were divided into polymorphic and monomorphic fragments. Three primers named OPA11, OPB15 and OPC07 did not show any monomorphic fragments. A number of 43 (7, 7, 8, 2, 9, 6 and 4) representing 60.56% were considered as unique DNA markers, and were amplified using OPA11, OPB15, OPC07, OPC18, OPD04, OPE05 and OPO14, respectively. Data shows similarity matrix between the four identified Streptomycs strains based on RAPD-PCR analysis ranged from 21.8 to 40.0. Results show that the P5CR gene was detected in the DNA extracts of three species, namely, Streptomyces cirratus-02; Streptomyces rishiriensis-04; Streptomyces luteogriseus-08, while, mtlD gene was only found in the DNA extracts of S. cirratus-02.Keywords: Streptomyces, halotolerant, salt tolerance genes, RAPD-PCR, Taif, KSAAfrican Journal of Biotechnology Vol. 12(13), pp. 1452-145

Umbilical hernia in children in a developing country: Does the season have an effect on the occurrence of strangulation?

No Abstract

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente