44 research outputs found
A revision of the ant genus Probolomyrmex (Hymenoptera: Formicidae: Proceratiinae) in Australia and Melanesia
Five species of the rarely encountered ant genus Probolomyrmex are known from Australia and Papua New Guinea, four of which are described here for the first time. Two species belong to the greavesi species-group (P. greavesi, P. latalongus sp. n.)while three belong to the longinodus species-group (P. aliundus sp. n., P. newguinensis sp. n., P. simplex sp. n.). The genus is now known to occur broadly across northern Australia and P. newguinensis and P. simplex are the first species of the genus described from Papua New Guinea. A key to Australian and Melanesian species is provided
Deflourination of drinking water using layered double Hydroxides
Safe drinking water is one of the prerequisites for a healthy life. In Sri Lanka 70% of the population
satisfy their water needs from ground water and as a result majority of them suffer from water related problems.
One of the pertaining problems prevailing in the dry zone of Sri Lanka is the presence of elevated levels of
fluoride ions in drinking water leading to many health related problems. Many studies have been carried out to
address the issue however little success has been reported up to date. This study focuses on suggesting a
nanotechnology based solution to deflourinate drinking water in the dry zone, Sri Lanka, for domestic water
tanks or as a region water purification solution. Layered double hydroxides (LDHs) which readily undergo anion
exchange reactions have been used as a suitable candidate for deflourination. The study further concentrates on
the regeneration of the material after removal of fluoride ions without releasing flouride ions back in to the water
cycle
Moult cycle specific differential gene expression profiling of the crab Portunus pelagicus
Background: Crustacean moulting is a complex process involving many regulatory pathways. A holistic approach to examine differential gene expression profiles of transcripts relevant to the moulting process, across all moult cycle stages, was used in this study. Custom cDNA microarrays were constructed for Portunus pelagicus. The printed arrays contained 5000 transcripts derived from both the whole organism, and from individual organs such as the brain, eyestalk, mandibular organ and Y-organ from all moult cycle stages.Results: A total of 556 clones were sequenced from the cDNA libraries used to construct the arrays. These cDNAs represented 175 singletons and 62 contigs, resulting in 237 unique putative genes. The gene sequences were classified into the following biological functions: cuticular proteins associated with arthropod exoskeletons, farnesoic acid O-methyltransferase (FaMeT), proteins belonging to the hemocyanin gene family, lectins, proteins relevant to lipid metabolism, mitochondrial proteins, muscle related proteins, phenoloxidase activators and ribosomal proteins. Moult cycle-related differential expression patterns were observed for many transcripts. Of particular interest were those relating to the formation and hardening of the exoskeleton, and genes associated with cell respiration and energy metabolism.Conclusions: The expression data presented here provide a chronological depiction of the molecular events associated with the biological changes that occur during the crustacean moult cycle. Tracing the temporal expression patterns of a large variety of transcripts involved in the moult cycle of P. pelagicus can provide a greater understanding of gene function, interaction, and regulation of both known and new genes with respect to the moulting process
Single-dose administration and the influence of the timing of the booster dose on immunogenicity and efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine: a pooled analysis of four randomised trials.
BACKGROUND: The ChAdOx1 nCoV-19 (AZD1222) vaccine has been approved for emergency use by the UK regulatory authority, Medicines and Healthcare products Regulatory Agency, with a regimen of two standard doses given with an interval of 4-12 weeks. The planned roll-out in the UK will involve vaccinating people in high-risk categories with their first dose immediately, and delivering the second dose 12 weeks later. Here, we provide both a further prespecified pooled analysis of trials of ChAdOx1 nCoV-19 and exploratory analyses of the impact on immunogenicity and efficacy of extending the interval between priming and booster doses. In addition, we show the immunogenicity and protection afforded by the first dose, before a booster dose has been offered. METHODS: We present data from three single-blind randomised controlled trials-one phase 1/2 study in the UK (COV001), one phase 2/3 study in the UK (COV002), and a phase 3 study in Brazil (COV003)-and one double-blind phase 1/2 study in South Africa (COV005). As previously described, individuals 18 years and older were randomly assigned 1:1 to receive two standard doses of ChAdOx1 nCoV-19 (5 × 1010 viral particles) or a control vaccine or saline placebo. In the UK trial, a subset of participants received a lower dose (2·2 × 1010 viral particles) of the ChAdOx1 nCoV-19 for the first dose. The primary outcome was virologically confirmed symptomatic COVID-19 disease, defined as a nucleic acid amplification test (NAAT)-positive swab combined with at least one qualifying symptom (fever ≥37·8°C, cough, shortness of breath, or anosmia or ageusia) more than 14 days after the second dose. Secondary efficacy analyses included cases occuring at least 22 days after the first dose. Antibody responses measured by immunoassay and by pseudovirus neutralisation were exploratory outcomes. All cases of COVID-19 with a NAAT-positive swab were adjudicated for inclusion in the analysis by a masked independent endpoint review committee. The primary analysis included all participants who were SARS-CoV-2 N protein seronegative at baseline, had had at least 14 days of follow-up after the second dose, and had no evidence of previous SARS-CoV-2 infection from NAAT swabs. Safety was assessed in all participants who received at least one dose. The four trials are registered at ISRCTN89951424 (COV003) and ClinicalTrials.gov, NCT04324606 (COV001), NCT04400838 (COV002), and NCT04444674 (COV005). FINDINGS: Between April 23 and Dec 6, 2020, 24 422 participants were recruited and vaccinated across the four studies, of whom 17 178 were included in the primary analysis (8597 receiving ChAdOx1 nCoV-19 and 8581 receiving control vaccine). The data cutoff for these analyses was Dec 7, 2020. 332 NAAT-positive infections met the primary endpoint of symptomatic infection more than 14 days after the second dose. Overall vaccine efficacy more than 14 days after the second dose was 66·7% (95% CI 57·4-74·0), with 84 (1·0%) cases in the 8597 participants in the ChAdOx1 nCoV-19 group and 248 (2·9%) in the 8581 participants in the control group. There were no hospital admissions for COVID-19 in the ChAdOx1 nCoV-19 group after the initial 21-day exclusion period, and 15 in the control group. 108 (0·9%) of 12 282 participants in the ChAdOx1 nCoV-19 group and 127 (1·1%) of 11 962 participants in the control group had serious adverse events. There were seven deaths considered unrelated to vaccination (two in the ChAdOx1 nCov-19 group and five in the control group), including one COVID-19-related death in one participant in the control group. Exploratory analyses showed that vaccine efficacy after a single standard dose of vaccine from day 22 to day 90 after vaccination was 76·0% (59·3-85·9). Our modelling analysis indicated that protection did not wane during this initial 3-month period. Similarly, antibody levels were maintained during this period with minimal waning by day 90 (geometric mean ratio [GMR] 0·66 [95% CI 0·59-0·74]). In the participants who received two standard doses, after the second dose, efficacy was higher in those with a longer prime-boost interval (vaccine efficacy 81·3% [95% CI 60·3-91·2] at ≥12 weeks) than in those with a short interval (vaccine efficacy 55·1% [33·0-69·9] at <6 weeks). These observations are supported by immunogenicity data that showed binding antibody responses more than two-fold higher after an interval of 12 or more weeks compared with an interval of less than 6 weeks in those who were aged 18-55 years (GMR 2·32 [2·01-2·68]). INTERPRETATION: The results of this primary analysis of two doses of ChAdOx1 nCoV-19 were consistent with those seen in the interim analysis of the trials and confirm that the vaccine is efficacious, with results varying by dose interval in exploratory analyses. A 3-month dose interval might have advantages over a programme with a short dose interval for roll-out of a pandemic vaccine to protect the largest number of individuals in the population as early as possible when supplies are scarce, while also improving protection after receiving a second dose. FUNDING: UK Research and Innovation, National Institutes of Health Research (NIHR), The Coalition for Epidemic Preparedness Innovations, the Bill & Melinda Gates Foundation, the Lemann Foundation, Rede D'Or, the Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca
The ant fauna of the Pilbara Bioregion, Western Australia
The ant fauna of the Pilbara Bioregion, which covers an area of ca. 179,000 km2, is reviewed. During surveys undertaken between May 2003 and September 2006, ants were one of the taxonomic groups to receive special attention. The total number of ant species recorded from 24 survey areas was 245, and these were placed in 37 genera and 9 subfamilies. Ants recorded from single quadrats (‘singletons’) accounted for 18.8% of the species. The most speciose genera were Camponotus (36 spp.), Iridomyrmex (31 spp.) and Melophorus (30 spp.). Based on current knowledge, 43% are purely Eremaean, 8% are primarily Bassian, 6% are primarily Torresian, nearly 17% occur over two of Australia’s three biogeographic divisions, and 25% are widespread over all three. At a quadrat level, there was no significant correlation between richness and any environmental variable, while clustering analysis revealed weak environmental correlations with ant assemblage composition. The classification at survey area level identified six groupings of ants; three climatic variables associated with these groupings were identified, namely annual temperature, precipitation in the coldest quarter of the year and annual precipitation
Clinical profile and sociodemographic aspects of trichomoniasis among females in the Western province of Sri Lanka
The objective of this study was to describe the sociodemographic aspects, presenting symptoms and findings of clinical examination of laboratory confirmed cases of trichomoniasis. Cases of trichomoniasis were studied, focusing on the sociodemographic aspects and presenting symptoms and signs at clinical examination. There were 29 laboratory confirmed cases of trichomoniasis. The infection was prevalent in equal proportions in all age groups (36-45, 15-25, 26-35 years- 38%, 31%, and 31%). The majority (76%) were married. There were 35% house wives and 28% sex workers. Contraceptives were not used by 48%. Only 41% were symptomatic at the time of detection. Out of those with a vaginal discharge, 50% complained of greenish yellow discharge and 34% a whitish thick discharge. In addition to the discharge, 7% had itching. None of the patients who were positive complained of dysuria. Findings at the clinical examination were mostly different to the symptoms described by the patients. On examination, the majority (81%) of T vaginalis infected women had a serous vaginal discharge and 14% a greenish yellow discharge. Twenty eight percent of infected females did not have any discharge. Presence of typical symptoms or type of vaginal discharge on examination cannot be used as the sole criterion for the diagnosis of trichomoniasis. These results indicate that treatment of patients based on symptoms per se can lead to over usage of metronidazole. This also shows the importance of laboratory support to diagnose T vaginalis infection. DOI: http://dx.doi.org/10.4038/sljid.v3i1.4690 </p
Towards the design of self-sorting nanomaterials through kinetically directed chemoselective control over interfacial surface chemistry
A gold nanoparticle platform is described in which post-synthesis surface modifications can be conducted using kinetically-tunable strain-promoted cycloaddition chemistry, which is dependent on the electronic properties of the complementary dipolar species. This permits chemoselective reactivity with one reactive dipole over another less reactive dipole, providing exciting opportinities for kinetically-directed self-sorting strategies