9,751 research outputs found

    Dates of birth and seasonal changes in well-being among 4904 subjects completing the seasonal pattern assessment questionnaire

    Get PDF
    Background: Abnormal distributions of birthdates, suggesting intrauterine aetiological factors, have been found in several psychiatric disorders, including one study of out-patients with Seasonal Affective Disorder (S.A.D.). We investigated birthdate distribution in relation to seasonal changes in well-being among a cohort who had completed the Seasonal Pattern Assessment Questionnaire (SPAQ). Method: A sample of 4904 subjects, aged 16 to 64, completed the SPAQ. 476 were cases of S.A.D. on the SPAQ and 580 were cases of sub-syndromal S.A.D. (S-S.A.D.). 92 were interview confirmed cases of S.A.D. Months and dates of birth were compared between S.A.D. cases and all others, between S.A.D. and S-S.A.D. cases combined and all others, and between interview confirmed cases and all others. Seasonality, as measured through seasonal fluctuations in well-being on the Global Seasonality Scores (GSS) of the SPAQ, was compared for all subjects by month and season of birth. Results: There was no evidence of an atypical pattern of birthdates for subjects fulfilling criteria for S.A.D., for the combined S.A.D. / S-S.A.D. group or for interview confirmed cases. There was also no relationship between seasonality on the GSS and month or season of birth. Limitations: Diagnoses of S.A.D. made by SPAQ criteria are likely to be overinclusive. Conclusion: Our findings differ from studies of patients with more severe mood disorders, including psychiatric out-patients with S.A.D. The lack of association between seasonality and birthdates in our study adds credence to the view that the aetiology of S.A.D. relates to separable factors predisposing to affective disorders and to seasonality

    Carboplatin binding to a model protein in non-NaCl conditions to eliminate partial conversion to cisplatin, and the use of different criteria to choose the resolution limit

    Full text link
    Hen egg white lysozyme (HEWL) co-crystallisation conditions of carboplatin without sodium chloride (NaCl) have been utilised to eliminate partial conversion of carboplatin to cisplatin observed previously. Tetragonal HEWL crystals were successfully obtained in 65% MPD with 0.1M citric acid buffer at pH 4.0 including DMSO. The X-ray diffraction data resolution to be used for the model refinement was reviewed using several topical criteria together. The CC1/2 criterion implemented in XDS led to data being significant to 2.0{\AA}, compared to the data only being able to be processed to 3.0{\AA} using the Bruker software package (SAINT). Then using paired protein model refinements and DPI values based on the FreeR value, the resolution limit was fine tuned to be 2.3{\AA}. Interestingly this was compared with results from the EVAL software package which gave a resolution limit of 2.2{\AA} solely using crossing 2, but 2.8{\AA} based on the Rmerge values (60%). The structural results showed that carboplatin bound to only the N{\delta} binding site of His-15 one week after crystal growth, whereas five weeks after crystal growth, two molecules of carboplatin are bound to the His-15 residue. In summary several new results have emerged: - firstly non-NaCl conditions showed a carboplatin molecule bound to His-15 of HEWL; secondly binding of one molecule of carboplatin was seen after one week of crystal growth and two molecules were bound after five weeks of crystal growth; and thirdly the use of several criteria to determine the diffraction resolution limit led to the successful use of data to higher resolution.Comment: 14 pages; submitted to Acta Cryst D Biological Crystallography reference number tz504

    Optical Quantum Computation with Perpetually Coupled Spins

    Full text link
    The possibility of using strongly and continuously interacting spins for quantum computation has recently been discussed. Here we present a simple optical scheme that achieves this goal while avoiding the drawbacks of earlier proposals. We employ a third state, accessed by a classical laser field, to create an effective barrier to information transfer. The mechanism proves to be highly efficient both for continuous and pulsed laser modes; moreover it is very robust, tolerating high decay rates for the excited states. The approach is applicable to a broad range of systems, in particular dense structures such as solid state self-assembled (e.g., molecular) devices. Importantly, there are existing structures upon which `first step' experiments could be immediately performed.Comment: 5 pages including 3 figures. Updated to published versio

    Ensemble based quantum metrology

    Full text link
    The field of quantum metrology promises measurement devices that are fundamentally superior to conventional technologies. Specifically, when quantum entanglement is harnessed the precision achieved is supposed to scale more favourably with the resources employed, such as system size and the time required. Here we consider measurement of magnetic field strength using an ensemble of spins, and we identify a third essential resource: the initial system polarisation, i.e. the low entropy of the original state. We find that performance depends crucially on the form of decoherence present; for a plausible dephasing model, we describe a quantum strategy which can indeed beat the standard quantum limit

    Quantum metrology with molecular ensembles

    Get PDF
    This work was supported by the EPSRC through QIP IRC (Grants No. GR/S82176/01 and No. GR/S15808/01), the National Research Foundation and Ministry of Education, Singapore, the DAAD, and the Royal Society.The field of quantum metrology promisesmeasurement devices that are fundamentally superior to conventional technologies. Specifically, when quantum entanglement is harnessed, the precision achieved is supposed to scale more favorably with the resources employed, such as system size and time required. Here, we consider measurement of magnetic-field strength using an ensemble of spin-active molecules. We identify a third essential resource: the change in ensemble polarization (entropy increase) during the metrology experiment. We find that performance depends crucially on the form of decoherence present; for a plausible dephasing model, we describe a quantum strategy, which can indeed beat the standard strategy.Publisher PDFPeer reviewe

    Metagenetic analysis of patterns of distribution and diversity of marine meiobenthic eukaryotes

    Get PDF
    AimMeiofaunal communities that inhabit the marine benthos offer unique opportunities to simultaneously study the macroecology of numerous phyla that exhibit different life-history strategies. Here, we ask: (1) if the macroecology of meiobenthic communities is explained mainly by dispersal constraints or by environmental conditions; and (2) if levels of meiofaunal diversity surpass existing estimates based on morphological taxonomy. LocationUK and mainland European coast. MethodsNext-generation sequencing techniques (NGS; Roche 454 FLX platform) using 18S nuclear small subunit ribosomal DNA (rDNA) gene. Pyrosequences were analysed using AmpliconNoise followed by chimera removal using Perseus. ResultsRarefaction curves revealed that sampling saturation was only reached at 15% of sites, highlighting that the bulk of meiofaunal diversity is yet to be discovered. Overall, 1353 OTUs were recovered and assigned to 23 different phyla. The majority of sampled sites had c. 60-70 unique operational taxonomic units (OTUs) per site, indicating high levels of beta diversity. The environmental parameters that best explained community structure were seawater temperature, geographical distance and sediment size, but most of the variability (R-2=70%-80%) remains unexplained. Main conclusionsHigh percentages of endemic OTUs suggest that meiobenthic community composition is partly niche-driven, as observed in larger organisms, but also shares macroecological features of microorganisms by showing high levels of cosmopolitanism (albeit on a much smaller scale). Meiobenthic communities exhibited patterns of isolation by distance as well as associations between niche, latitude and temperature, indicating that meiobenthic communities result from a combination of niche assembly and dispersal processes. Conversely, isolation-by-distance patterns were not identified in the featured protists, suggesting that animals and protists adhere to radically different macroecological processes, linked to life-history strategies.Natural Environment Research Council (NERC) [NE/E001505/1, NE/F001266/1, MGF-167]; Portuguese Foundation for Science and Technology (FCT) [SFRH/BD/27413/2006, SFRH/BPD/80447/2014]; EPSRC [EP/H003851/1]; BBSRC CASE studentship; Unilever; Biotechnology and Biological Sciences Research Council [987347]; Engineering and Physical Sciences Research Council [EP/H003851/1]; Natural Environment Research Council [NE/F001290/1, NE/F001266/1, NE/E001505/1, NBAF010002]info:eu-repo/semantics/publishedVersio

    Intraocular pressure in inbred mouse strains

    Get PDF
    PURPOSE: To develop a protocol to measure the intraocular pressure (IOP) of living mice and to determine the IOP of genetically different mouse strains. METHODS: Eyes of anesthetized animals were cannulated with a very fine fluid-filled glass microneedle. The microneedle was connected to a pressure transducer, and the pressure signal was analyzed with a computer system. Intraocular pressures of male C3H/He iota, C57BL/ 6 iota, A/iota, and BALB/c iota mice were determined. RESULTS: Differences in IOP were detected between genetically distinct mouse strains maintained in virtually identical environments. C3H/He iota was the strain with the highest average IOP (13.7 +/- 0.8 mm Hg). This strain average was 1.4 mm Hg higher than that for C57BL/6 iota (12.3 +/- 0.5 mm Hg; P = 0.14), 4.3 mm Hg higher than that for A/iota (9.4 +/- 0.5 mm Hg; P < 0.001), and 6 mm Hg higher than that for BALB/c iota (7.7 +/- 0.5 mm Hg; P < 0.001). CONCLUSIONS: The authors have developed an accurate and reliable procedure for measuring intraocular pressure in living mice. This procedure can detect IOP differences between groups of mice that differ by genotype

    Ocular hypertension suppresses homeostatic gene expression in optic nerve head microglia of DBA/2 J mice.

    Get PDF
    Glaucoma is the leading cause of irreversible vision loss. Ocular hypertension is a major risk factor for glaucoma and recent work has demonstrated critical early neuroinflammatory insults occur in the optic nerve head following ocular hypertension. Microglia and infiltrating monocytes are likely candidates to drive these neuroinflammatory insults. However, the exact molecular identity / transcriptomic profile of microglia following ocular hypertensive insults is unknown. To elucidate the molecular identity of microglia after long-term exposure to ocular hypertension, we used a mouse model of glaucoma (DBA/2 J). We performed RNA-sequencing of microglia mRNA from the optic nerve head at a time point following ocular hypertensive insults, but preceding detectable neurodegeneration (with microglia identified as being CD4

    Погляд на архіви

    Get PDF
    The International Union of Crystallography has for many years been advocating archiving of raw data to accompany structural papers. Recently, it initiated the formation of the Diffraction Data Deposition Working Group with the aim of developing standards for the representation of these data. A means of studying this issue is to submit exemplar publications with associated raw data and metadata. A recent study on the effects of dimethyl sulfoxide on the binding of cisplatin and carboplatin to histidine in 11 different lysozyme crystals from two diffractometers led to an investigation of the possible effects of the equipment and X-ray diffraction data processing software on the calculated occupancies and B factors of the bound Pt compounds. 35.3 Gb of data were transferred from Manchester to Utrecht to be processed with EVAL. A systematic comparison shows that the largest differences in the occupancies and B factors of the bound Pt compounds are due to the software, but the equipment also has a noticeable effect. A detailed description of and discussion on the availability of metadata is given. By making these raw diffraction data sets available via a local depository, it is possible for the diffraction community to make their own evaluation as they may wish
    corecore