263 research outputs found
Rapid chemical test for the identification of chromium-molybdenum steel
This note describes a simple, rapid, qualitative test which can be applied to solutions of drilling or chips for the identification of chromium-molybdenum steel. The test is based on the orange-red compound which is formed when thiocyanate and inequivalent molybdenum react. This test is much more reliable than the potassium ethylxanthate test which has been recommended for a like purpose. A list of the apparatus and reagents which are required, and a description of the procedure follows
Evolving the service model for child and adolescent mental health services
A new model for a community mental health service for children and young people aged 0-18 years is described. This has been formulated after multi-level consultation including extensive user/carer involvement. The proposed model is multidisciplinary and integrated with multiagency provision, with smooth access onto and through care pathways. This model brings voluntary and statutory agencies into an integrated collaboration. It reinforces that social and emotional development and psychological functioning is everybodyâs business and creates conditions where a childâs needs can be addressed on a day-to-day basis rather than through a âclinic-based modelâ.</jats:p
Investigations of Aerobic Methane Oxidation in Two Marine Seep Environments: Part 1âChemical Kinetics
Microbial aerobic oxidation is known to be a significant sink of marine methane (CH4), contributing to the relatively minor atmospheric release of this greenhouse gas over vast stretches of the ocean. However, the chemical kinetics of aerobic CH4 oxidation are not well established, making it difficult to predict and assess the extent that CH4 is oxidized in seawater following seafloor release. Here we investigate the kinetics of aerobic CH4 oxidation using mesocosm incubations of fresh seawater samples collected from seep fields in Hudson Canyon, U.S. Atlantic Margin and MC118, Gulf of Mexico to gain a fundamental chemical understanding of this CH4 sink. The goals of this investigation were to determine the response or lag time following CH4 release until more rapid oxidation begins, the reaction order, and the stoichiometry of reactants utilized (i.e., CH4, oxygen, nitrate, phosphate, trace metals) during CH4 oxidation. The results for both Hudson Canyon and MC118 environments show that CH4 oxidation rates sharply increased within less than one month following the CH4 inoculation of seawater. However, the exact temporal characteristics of this more rapid CH4 oxidation varied based on location, possibly dependent on the local circulation and biogeochemical conditions at the point of seawater collection. The data further suggest that methane oxidation behaves as a firstâorder kinetic process and that the reaction rate constant remains constant once rapid CH4 oxidation begins
Investigations of Aerobic Methane Oxidation in Two Marine Seep Environments: Part 2âIsotopic Kinetics
During aerobic oxidation of methane (CH4) in seawater, a process which mitigates atmospheric emissions, the 12Câisotopologue reacts with a slightly greater rate constant than the 13Câisotopologue, leaving the residual CH4 isotopically fractionated. Prior studies have attempted to exploit this systematic isotopic fractionation from methane oxidation to quantify the extent that a CH4 pool has been oxidized in seawater. However, cultivationâbased studies have suggested that isotopic fractionation fundamentally changes as a microbial population blooms in response to an influx of reactive substrates. Using a systematic mesocosm incubation study with recently collected seawater, here we investigate the fundamental isotopic kinetics of aerobic CH4 oxidation during a microbial bloom. As detailed in a companion paper, seawater samples were collected from seep fields in Hudson Canyon, U.S. Atlantic Margin, and atop Woolsey Mound (also known as Sleeping Dragon) which is part of lease block MC118 in the northern Gulf of Mexico, and used in these investigations. The results from both Hudson Canyon and MC118 show that in these natural environments isotopic fraction for CH4 oxidation follows a firstâorder kinetic process. The results also show that the isotopic fractionation factor remains constant during this methanotrophic bloom once rapid CH4 oxidation begins and that the magnitude of the fractionation factor appears correlated with the firstâorder reaction rate constant. These findings greatly simplify the use of natural stable isotope changes in CH4 to assess the extent that CH4 is oxidized in seawater following seafloor release
Bone marrow lesions and magnetic resonanceImagingâdetected structural abnormalities in patients with midfoot pain and osteoarthritis: A cross-sectional study
To compare magnetic resonance imaging (MRI)âdetected structural abnormalities in patients withsymptomatic midfoot osteoarthritis (OA), patients with persistent midfoot pain, and asymptomatic controls, and toexplore the association between MRI features, pain, and foot-related disability. One hundred seven adults consisting of 50 patients with symptomatic and radiographically confirmedmidfoot OA, 22 adults with persistent midfoot pain but absence of radiographic OA, and 35 asymptomatic adultsunderwent 3T MRI of the midfoot and clinical assessment. MRIs were read for the presence and severity of abnormal-ities (bone marrow lesions [BMLs], subchondral cysts, osteophytes, joint space narrowing [JSN], effusion-synovitis,tenosynovitis, and enthesopathy) using the Foot Osteoarthritis MRI Score. Pain and foot-related disability wereassessed with the Manchester Foot Pain and Disability Index. The severity sum score of BMLs in the midfoot was greater in patients with midfoot pain and no signs ofOA on radiography compared to controls (P= 0.007), with a pattern of involvement in the cuneiformâmetatarsal jointssimilar to that in patients with midfoot OA. In univariable models, BMLs (Ď= 0.307), JSN (Ď= 0.423), and subchondralcysts (Ď= 0.302) were positively associated with pain (P< 0.01). In multivariable models, MRI abnormalities were notassociated with pain and disability when adjusted for covariates. In individuals with persistent midfoot pain but no signs of OA on radiography, MRIfindings suggestedan underrecognized prevalence of OA, particularly in the second and third cuneiformâmetatarsal joints, where BMLpatterns were consistent with previously recognized sites of elevated mechanical loading. Joint abnormalities werenot strongly associated with pain or foot-related disability
Interplay of cis and trans mechanisms driving transcription factor binding and gene expression evolution
Noncoding regulatory variants play a central role in the genetics of human diseases and in evolution. Here we measure allele-specific transcription factor binding occupancy of three liver-specific transcription factors between crosses of two inbred mouse strains to elucidate the regulatory mechanisms underlying transcription factor binding variations in mammals. Our results highlight the pre-eminence of cis-acting variants on transcription factor occupancy divergence. Transcription factor binding differences linked to cis-acting variants generally exhibit additive inheritance, while those linked to trans-acting variants are most often dominantly inherited. Cis-acting variants lead to local coordination of transcription factor occupancies that decay with distance; distal coordination is also observed and may be modulated by long-range chromatin contacts. Our results reveal the regulatory mechanisms that interplay to drive transcription factor occupancy, chromatin state, and gene expression in complex mammalian cell states.We thank the CRUKâCI Genomics, BRU, and Bioinformatics Cores for technical assistance and the EMBL-EBI systems team for management of computational resources. This research was supported by the European Molecular Biology Laboratory (E.S.W., D.T., J.C.M., P.F.), Cancer Research UK (B.M.S., T.F.R., F.C., C.F., A.R., D.T.O.), the BOLD ITN (B.M.S.), Darwin Fellowship (A.K.), the Wellcome Trust (WT202878/B/16/Z, WT108749/Z/15/Z) (P.F.), (WT202878/A/16/Z) (D.T.O), (WT095606) (A.C.F.-S) and (WT098051) (P.F., D.T.O.), EMBO Long-term (ALTF1518-2012) and Advanced Fellowships (aALTF1672-2014) (E.S.W.), and by the European Research Council (award 615584) and EMBO Young Investigator Programme (D.T.O.)
Computed cardiopulmonography and the idealized lung clearance index, iLCI2.5, in early-stage cystic fibrosis
This study explored the use of computed cardiopulmonography (CCP) to assess lung function in early-stage cystic fibrosis (CF). CCP has two components. The first is a particularly accurate technique for measuring gas exchange. The second is a computational cardiopulmonary model where patient-specific parameters can be estimated from the measurements of gas exchange. Twenty-five participants (14 healthy controls, 11 early-stage CF) were studied with CCP. They were also studied with a standard clinical protocol to measure the lung clearance index (LCI2.5). Ventilation inhomogeneity, as quantified through CCP parameter ĎlnCl, was significantly greater (P < 0.005) in CF than in controls, and anatomical deadspace relative to predicted functional residual capacity (DS/FRCpred) was significantly more variable (P < 0.002). Participant-specific parameters were used with the CCP model to calculate idealized values for LCI2.5 (iLCI2.5) where extrapulmonary influences on the LCI2.5, such as breathing pattern, had all been standardized. Both LCI2.5 and iLCI2.5 distinguished clearly between CF and control participants. LCI2.5 values were mostly higher than iLCI2.5 values in a manner dependent on the participantâs respiratory rate (r = 0.46, P < 0.05). The within-participant reproducibility for iLCI2.5 appeared better than for LCI2.5, but this did not reach statistical significance (F ratio = 2.2, P = 0.056). Both a sensitivity analysis on iLCI2.5 and a regression analysis on LCI2.5 revealed that these depended primarily on an interactive term between CCP parameters of the form ĎlnCL*(DS/FRC). In conclusion, the LCI2.5 (or iLCI2.5) probably reflects an amalgam of different underlying lung changes in early-stage CF that would require a multiparameter approach, such as potentially CCP, to resolve
European security in the 1990s and beyond : the implications of the accession of Cyprus and Malta to the European Union
For the last decade, the dramatic events in eastern and central Europe have (rightly)
dominated the security debate in Europe and, indeed, the wider world. One of the
consequences of this has been that the traditional neglect of the Mediterranean region has
been compounded. However, there are now signs-notably the recent Barcelona conference
at which the European Union's Mediterranean policy was relaunched and extended (to incorporate the grand design of a Mediterranean free trade area) - that the Mediterranean is, at last, receiving some of the attention it deserves and justifies.peer-reviewe
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Perchlorate Exposure Reduces Primordial Germ Cell Number in Female Threespine Stickleback
Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs) begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14â18 days post fertilization (dpf). We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development
Deletion of parasite immune modulatory sequences combined with immune activating signals enhances vaccine mediated protection against filarial nematodes
<p>Background: Filarial nematodes are tissue-dwelling parasites that can be killed by Th2-driven immune effectors, but that have evolved to withstand immune attack and establish chronic infections by suppressing host immunity. As a consequence, the efficacy of a vaccine against filariasis may depend on its capacity to counter parasite-driven immunomodulation.</p>
<p>Methodology and Principal Findings: We immunised mice with DNA plasmids expressing functionally-inactivated forms of two immunomodulatory molecules expressed by the filarial parasite Litomosoides sigmodontis: the abundant larval transcript-1 (LsALT) and cysteine protease inhibitor-2 (LsCPI). The mutant proteins enhanced antibody and cytokine responses to live parasite challenge, and led to more leukocyte recruitment to the site of infection than their native forms. The immune response was further enhanced when the antigens were targeted to dendritic cells using a single chain Fv-ÎąDEC205 antibody and co-administered with plasmids that enhance T helper 2 immunity (IL-4) and antigen-presenting cell recruitment (Flt3L, MIP-1Îą). Mice immunised simultaneously against the mutated forms of LsALT and LsCPI eliminated adult parasites faster and consistently reduced peripheral microfilaraemia. A multifactorial analysis of the immune response revealed that protection was strongly correlated with the production of parasite-specific IgG1 and with the numbers of leukocytes present at the site of infection.</p>
<p>Conclusions: We have developed a successful strategy for DNA vaccination against a nematode infection that specifically targets parasite-driven immunosuppression while simultaneously enhancing Th2 immune responses and parasite antigen presentation by dendritic cells.</p>
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