3,964 research outputs found
Sea anemones may thrive in a high CO2 world
Increased seawater pCO 2, and in turn 'ocean acidification' (OA), is predicted to profoundly impact marine ecosystem diversity and function this century. Much research has already focussed on calcifying reef-forming corals (Class: Anthozoa) that appear particularly susceptible to OA via reduced net calcification. However, here we show that OA-like conditions can simultaneously enhance the ecological success of non-calcifying anthozoans, which not only play key ecological and biogeochemical roles in present day benthic ecosystems but also represent a model organism should calcifying anthozoans exist as less calcified (soft-bodied) forms in future oceans. Increased growth (abundance and size) of the sea anemone (Anemonia viridis) population was observed along a natural CO 2 gradient at Vulcano, Italy. Both gross photosynthesis (P G) and respiration (R) increased with pCO 2 indicating that the increased growth was, at least in part, fuelled by bottom up (CO 2 stimulation) of metabolism. The increase of P G outweighed that of R and the genetic identity of the symbiotic microalgae (Symbiodinium spp.) remained unchanged (type A19) suggesting proximity to the vent site relieved CO 2 limitation of the anemones' symbiotic microalgal population. Our observations of enhanced productivity with pCO 2, which are consistent with previous reports for some calcifying corals, convey an increase in fitness that may enable non-calcifying anthozoans to thrive in future environments, i.e. higher seawater pCO 2. Understanding how CO 2-enhanced productivity of non- (and less-) calcifying anthozoans applies more widely to tropical ecosystems is a priority where such organisms can dominate benthic ecosystems, in particular following localized anthropogenic stress. © 2012 Blackwell Publishing Ltd
Assessing connectivity between an overlying aquifer and a coal seam gas resource using methane isotopes, dissolved organic carbon and tritium
Coal seam gas (CSG) production can have an impact on groundwater quality and quantity in adjacent or overlying aquifers. To assess this impact we need to determine the background groundwater chemistry and to map geological pathways of hydraulic connectivity between aquifers. In south-east Queensland (Qld), Australia, a globally important CSG exploration and production province, we mapped hydraulic connectivity between the Walloon Coal Measures (WCM, the target formation for gas production) and the overlying Condamine River Alluvial Aquifer (CRAA), using groundwater methane (CH4) concentration and isotopic composition (δ13C-CH4), groundwater tritium (3H) and dissolved organic carbon (DOC) concentration. A continuous mobile CH4 survey adjacent to CSG developments was used to determine the source signature of CH4 derived from the WCM. Trends in groundwater δ13C-CH4 versus CH4 concentration, in association with DOC concentration and 3H analysis, identify locations where CH4 in the groundwater of the CRAA most likely originates from the WCM. The methodology is widely applicable in unconventional gas development regions worldwide for providing an early indicator of geological pathways of hydraulic connectivity
Healthcare use for acute gastrointestinal illness in two Inuit communities: Rigolet and Iqaluit, Canada
Background. The incidence of self-reported acute gastrointestinal illness (AGI) in Rigolet, Nunatsiavut, and Iqaluit, Nunavut, is higher than reported elsewhere in Canada; as such, understanding AGI-related healthcare use is important for healthcare provision, public health practice and surveillance of AGI. Objectives: This study described symptoms, severity and duration of self-reported AGI in the general population and examined the incidence and factors associated with healthcare utilization for AGI in these 2 Inuit communities. Design: Cross-sectional survey data were analysed using multivariable exact logistic regression to examine factors associated with individuals’ self-reported healthcare and over-the-counter (OTC) medication utilization related to AGI symptoms. Results: In Rigolet, few AGI cases used healthcare services [4.8% (95% CI=1.5-14.4%)]; in Iqaluit, some cases used healthcare services [16.9% (95% CI=11.2-24.7%)]. Missing traditional activities due to AGI (OR=3.8; 95% CI=1.18-12.4) and taking OTC medication for AGI symptoms (OR=3.8; 95% CI=1.2-15.1) were associated with increased odds of using healthcare services in Iqaluit. In both communities, AGI severity and secondary symptoms (extreme tiredness, headache, muscle pains, chills) were significantly associated with increased odds of taking OTC medication. Conclusions: While rates of self-reported AGI were higher in Inuit communities compared to non-Inuit communities in Canada, there were lower rates of AGI-related healthcare use in Inuit communities compared to other regions in Canada. As such, the rates of healthcare use for a given disease can differ between Inuit and non-Inuit communities, and caution should be exercised in making comparisons between Inuit and non-Inuit health outcomes based solely on clinic records and healthcare use
Estimating the incidence of acute infectious intestinal disease in the community in the UK:A retrospective telephone survey
Objectives: To estimate the burden of intestinal infectious disease (IID) in the UK and determine whether disease burden estimations using a retrospective study design differ from those using a prospective study design. Design/Setting: A retrospective telephone survey undertaken in each of the four countries comprising the United Kingdom. Participants were randomly asked about illness either in the past 7 or 28 days. Participants: 14,813 individuals for all of whom we had a legible recording of their agreement to participate Outcomes: Self-reported IID, defined as loose stools or clinically significant vomiting lasting less than two weeks, in the absence of a known non-infectious cause. Results: The rate of self-reported IID varied substantially depending on whether asked for illness in the previous 7 or 28 days. After standardising for age and sex, and adjusting for the number of interviews completed each month and the relative size of each UK country, the estimated rate of IID in the 7-day recall group was 1,530 cases per 1,000 person-years (95% CI: 1135 – 2113), while in the 28-day recall group it was 533 cases per 1,000 person-years (95% CI: 377 – 778). There was no significant variation in rates between the four countries. Rates in this study were also higher than in a related prospective study undertaken at the same time. Conclusions: The estimated burden of disease from IID varied dramatically depending on study design. Retrospective studies of IID give higher estimates of disease burden than prospective studies. Of retrospective studies longer recall periods give lower estimated rates than studies with short recall periods. Caution needs to be exercised when comparing studies of self-reported IID as small changes in study design or case definition can markedly affect estimated rates
How to minimise the effect of tumour cell content in detection of aberrant genetic markers in neuroblastoma
Background:Clinical heterogeneity reflects the complexity of genetic events associated with neuroblastoma (NB). To identify the status of all described genetic loci with possible prognostic interest, high-throughput approaches have been used, but only with tumour cell content >60%. In some tumours, necrotic, haemorrhagic and/or calcification areas influence the low amount of neuroblasts. We evaluated the effect of tumour cell content in the detection of relevant aberrant genetic markers (AGM) diagnosed by fluorescence in situ hybridisation (FISH) on tissue microarrays (TMA) in NB.Methods:Two hundred and thirty-three MYCN non-amplified primary NB included in 12 TMAs were analysed.Results:Presence of AGM reduced event-free survival (EFS) (P=0.004) as well as overall survival (OS) (P=0.004) of patients in the whole cohort. There were no differences in prognostic impact of presence of AGM according to tumour cell content.Conclusion:We propose the use of FISH to diagnose AGM of all NB samples having the above-mentioned areas to determine patient risk
Solução glicosada hipertônica no mesentério e no peritônio de ratos: estudo macroscópico e microscópico
PURPOSE: The objective of the experimental study is to detect the macroscopic and microscopic alterations of the mesenterium and parietal peritoneum when hypertonic glucose aqueous solution 10%-25% is administrated into the peritoneal cavity of the rat. METHODS: 90 Wistar females young rats adults were used weighin between 180-250 g, numbered 1 to 90, establishing unique group and divided in three groups (A, B, C) of 30 animals chosen aleatory manner. 0,9% saline solution was used called control group, or group A, 10% glucose solution named group B, and in the others 30 was used 25% glucose solution named group C, differing in the observation period, (06h, 24h and 48h), but with the same procedure. A midline abdominal wall laparotomy was made and in the animals of the control group was injected 2 ml of a 0,9% saline solution into the peritoneal cavity. After, we made a suture in mass without to include the peritoneum. For the others groups (B, C) the rats received 10% glucose solution and 25% glucose solution injected into the peritoneal cavity respectively. All groups were kept under observation and the results were submitted to statistical analysis by a longitudinal and transversal comparative study. RESULTS: A new surgery was done in 6h, 24h and 48h, and we observed in macroscopic evaluation, the presence of fluid, serous uniforme and rosy all over the cavity. Vascular congestion was present. We dried out 90 fragments of mesenterium and 90 fragments of parietal peritonium bilateral. In the microscopic study, necrosis was not present. For the mesenterium histological study we observed 16 cases (17,8%) unspecific chronic inflammation, 30 cases (33,4%) hiperplasic linfonod, 10 cases (11,1%) high vascular congestion, 6 cases (6,6%) reaction fibrosis and 28 cases (31,1%) no alteration. For the parietal peritonium histological study we observed 6 cases (3,3%) reaction fibrosis and 174 cases (96,7%) no alteration. Giant cell was not present. In the statistical analisys statistic there is no significance between the groups (p>0,05). CONCLUSION: Hypertonic glucose solution and NaCl 0,9% on the mesenterium and parietal peritonium do not produce tissue necrosis in a rat and the inflammation process has the same intensity.OBJETIVO: Investigar as alterações macroscópicas e microscópicas do mesentério e do peritônio parietal quando se administra a solução aquosa de glicose hipertônica a 10% e a 25% na cavidade peritoneal de rato. MÉTODOS: 90 ratos fêmeas (n=90), adultos, Wistar, jovens, com peso variando de 180 a 250 gramas foram divididos em 3 sub-grupos (A, B e C) contendo cada um 30 animais com procedimentos idênticos, diferindo apenas no período de observação. Os números de 1 a 30 constituem o grupo A ou grupo-controle (NaCl 0,9%), os números de 31 a 60 constituem o grupo B ou grupo-glicose a 10% e os números de 61 a 90 constituem o grupo C ou grupo- glicose a 25%. Realizando-se posteriormente laparotomia com incisão mediana longitudinal de pele a 2 cm abaixo do processo Xiphoideus sterni, estendendo-se por 3 cm caudalmente na linha média ventral. A escolha do procedimento a ser realizado para introdução na cavidade peritoneal de 2 ml de uma solução de cloreto de sódio 0,9% (controle), de glicose hipertônica a 10% e de glicose hipertônica a 25%. Em períodos correspondentes às 6h, 24h e 48h de pós-operatório, os animais de cada grupo foram reoperados, sendo realizada avaliação macroscópica e microscópica além dos registros das alterações histológicas do mesentério e peritônio parietal. RESULTADOS: Na microscopia do mesentério observou-se que 30 animais (33,4%) apresentaram linfonodos hiperplásicos; 6 animais (6,6%) com fibrose reacional; 10 animais (11,1%) com intensa congestão vascular; 16 animais (17,8%) com inflamação crônica inespecífica; 28 casos (31,1%) sem alteração. A microscopia do peritônio revelou 6 casos com fibrose reacional (3,3%) 174 casos (96,7%) sem alteração histológica. CONCLUSÃO: As soluções de glicose a 10% e a 25% não causam necrose tecidual quando introduzidas na cavidade peritoneal. O processo reacional inflamatório é de igual intensidade tecidual comparando-se ao uso da solução de NaCl a 0,9%.UNCISAL DepartmentUFAL Morphology Department and Human AnatomyUNIFESP-EPM Surgery DepartmentUNIFESP, EPM, Surgery DepartmentSciEL
Kank Is an EB1 Interacting Protein that Localises to Muscle-Tendon Attachment Sites in Drosophila
Little is known about how microtubules are regulated in different cell types during development. EB1 plays a central role in the regulation of microtubule plus ends. It directly binds to microtubule plus ends and recruits proteins which regulate microtubule dynamics and behaviour. We report the identification of Kank, the sole Drosophila orthologue of human Kank proteins, as an EB1 interactor that predominantly localises to embryonic attachment sites between muscle and tendon cells. Human Kank1 was identified as a tumour suppressor and has documented roles in actin regulation and cell polarity in cultured mammalian cells. We found that Drosophila Kank binds EB1 directly and this interaction is essential for Kank localisation to microtubule plus ends in cultured cells. Kank protein is expressed throughout fly development and increases during embryogenesis. In late embryos, it accumulates to sites of attachment between muscle and epidermal cells. A kank deletion mutant was generated. We found that the mutant is viable and fertile without noticeable defects. Further analysis showed that Kank is dispensable for muscle function in larvae. This is in sharp contrast to C. elegans in which the Kank orthologue VAB-19 is required for development by stabilising attachment structures between muscle and epidermal cells
Radiative contribution to neutrino masses and mixing in SSM
In an extension of the minimal supersymmetric standard model (popularly known
as the SSM), three right handed neutrino superfields are introduced to
solve the -problem and to accommodate the non-vanishing neutrino masses
and mixing. Neutrino masses at the tree level are generated through parity
violation and seesaw mechanism. We have analyzed the full effect of one-loop
contributions to the neutrino mass matrix. We show that the current three
flavour global neutrino data can be accommodated in the SSM, for both
the tree level and one-loop corrected analyses. We find that it is relatively
easier to accommodate the normal hierarchical mass pattern compared to the
inverted hierarchical or quasi-degenerate case, when one-loop corrections are
included.Comment: 51 pages, 14 figures (58 .eps files), expanded introduction, other
minor changes, references adde
Smc5/6 coordinates formation and resolution of joint molecules with chromosome morphology to ensure meiotic divisions
During meiosis, Structural Maintenance of Chromosome (SMC) complexes underpin two fundamental features of meiosis: homologous recombination and chromosome segregation. While meiotic functions of the cohesin and condensin complexes have been delineated, the role of the third SMC complex, Smc5/6, remains enigmatic. Here we identify specific, essential meiotic functions for the Smc5/6 complex in homologous recombination and the regulation of cohesin. We show that Smc5/6 is enriched at centromeres and cohesin-association sites where it regulates sister-chromatid cohesion and the timely removal of cohesin from chromosomal arms, respectively. Smc5/6 also localizes to recombination hotspots, where it promotes normal formation and resolution of a subset of joint-molecule intermediates. In this regard, Smc5/6 functions independently of the major crossover pathway defined by the MutLγ complex. Furthermore, we show that Smc5/6 is required for stable chromosomal localization of the XPF-family endonuclease, Mus81-Mms4Eme1. Our data suggest that the Smc5/6 complex is required for specific recombination and chromosomal processes throughout meiosis and that in its absence, attempts at cell division with unresolved joint molecules and residual cohesin lead to severe recombination-induced meiotic catastroph
Spontaneous R-Parity Violation, Flavor Symmetry and Tribimaximal Mixing
We explore the possibility of spontaneous R parity violation in the context
of flavor symmetry. Our model contains singlet matter chiral superfields which are arranged as triplet of
and as well as few additional Higgs chiral superfields which are singlet
under MSSM gauge group and belong to triplet and singlet representation under
the flavor symmetry. R parity is broken spontaneously by the vacuum
expectation values of the different sneutrino fields and hence we have
neutrino-neutralino as well as neutrino-MSSM gauge singlet higgsino mixings in
our model, in addition to the standard model neutrino- gauge singlet neutrino,
gaugino-higgsino and higgsino-higgsino mixings. Because all of these mixings we
have an extended neutral fermion mass matrix. We explore the low energy
neutrino mass matrix for our model and point out that with some specific
constraints between the sneutrino vacuum expectation values as well as the MSSM
gauge singlet Higgs vacuum expectation values, the low energy neutrino mass
matrix will lead to a tribimaximal mixing matrix. We also analyze the potential
minimization for our model and show that one can realize a higher vacuum
expectation value of the singlet
sneutrino fields even when the other sneutrino vacuum expectation values are
extremely small or even zero.Comment: 18 page
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