167 research outputs found

    Stability constants for some divalent metal ion/crown ether complexes in methanol determined by polarography and conductometry

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    Stability constants in methanol at 25.0°C were evaluated for the complexes of the divalent cations Ca2+, Ni2+, Zn2+, Pb2+, Mg2+, Co2+ and Cu2+ with the macrocyclic polyethers 15-crown-5 (15C5), 18-crown-6 (18C6), dicyclohexyl-18-crown-6 (DC18C6) and dibenzo-24-crown-8 (DB24C8). The log K values of the 1:1 complexes were generally in the range 2.1–4.2, which is low in comparison to the values of the corresponding crown ether/alkali metal ion complexes. M2L complexes were observed for the systems Pb2+/18C6, Pb2+/DC18C6, Ca2+/DC18C6 and Cu2+/D18C6, whereas ML2 complexes were found for Ca2+/18C6 and Cu2+/18C6. Within the series of complexes studied, there was no clear relationship between cation diameter and hole size

    Polymer tensiometers with ceramic cones: direct observations of matric pressures in drying soils

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    Measuring soil water potentials is crucial to characterize vadose zone processes. Conventional tensiometers only measure until approximately −0.09 MPa, and indirect methods may suffer from the non-uniqueness in the relationship between matric potential and measured properties. Recently developed polymer tensiometers (POTs) are able to directly measure soil matric potentials until the theoretical wilting point (−1.6 MPa). By minimizing the volume of polymer solution inside the POT while maximizing the ceramic area in contact with that polymer solution, response times drop to acceptable ranges for laboratory and field conditions. Contact with the soil is drastically improved with the use of cone-shaped solid ceramics instead of flat ceramics. The comparison between measured potentials by polymer tensiometers and indirectly obtained potentials with time domain reflectometry highlights the risk of using the latter method at low water contents. By combining POT and time domain reflectometry readings in situ moisture retention curves can be measured over the range permitted by the measurement range of both POT and time domain reflectometry

    ENIGMA and global neuroscience: A decade of large-scale studies of the brain in health and disease across more than 40 countries

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    This review summarizes the last decade of work by the ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) Consortium, a global alliance of over 1400 scientists across 43 countries, studying the human brain in health and disease. Building on large-scale genetic studies that discovered the first robustly replicated genetic loci associated with brain metrics, ENIGMA has diversified into over 50 working groups (WGs), pooling worldwide data and expertise to answer fundamental questions in neuroscience, psychiatry, neurology, and genetics. Most ENIGMA WGs focus on specific psychiatric and neurological conditions, other WGs study normal variation due to sex and gender differences, or development and aging; still other WGs develop methodological pipelines and tools to facilitate harmonized analyses of "big data" (i.e., genetic and epigenetic data, multimodal MRI, and electroencephalography data). These international efforts have yielded the largest neuroimaging studies to date in schizophrenia, bipolar disorder, major depressive disorder, post-traumatic stress disorder, substance use disorders, obsessive-compulsive disorder, attention-deficit/hyperactivity disorder, autism spectrum disorders, epilepsy, and 22q11.2 deletion syndrome. More recent ENIGMA WGs have formed to study anxiety disorders, suicidal thoughts and behavior, sleep and insomnia, eating disorders, irritability, brain injury, antisocial personality and conduct disorder, and dissociative identity disorder. Here, we summarize the first decade of ENIGMA's activities and ongoing projects, and describe the successes and challenges encountered along the way. We highlight the advantages of collaborative large-scale coordinated data analyses for testing reproducibility and robustness of findings, offering the opportunity to identify brain systems involved in clinical syndromes across diverse samples and associated genetic, environmental, demographic, cognitive, and psychosocial factors

    ENIGMA-anxiety working group: Rationale for and organization of large-scale neuroimaging studies of anxiety disorders

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    Anxiety disorders are highly prevalent and disabling but seem particularly tractable to investigation with translational neuroscience methodologies. Neuroimaging has informed our understanding of the neurobiology of anxiety disorders, but research has been limited by small sample sizes and low statistical power, as well as heterogenous imaging methodology. The ENIGMA‐Anxiety Working Group has brought together researchers from around the world, in a harmonized and coordinated effort to address these challenges and generate more robust and reproducible findings. This paper elaborates on the concepts and methods informing the work of the working group to date, and describes the initial approach of the four subgroups studying generalized anxiety disorder, panic disorder, social anxiety disorder, and specific phobia. At present, the ENIGMA‐Anxiety database contains information about more than 100 unique samples, from 16 countries and 59 institutes. Future directions include examining additional imaging modalities, integrating imaging and genetic data, and collaborating with other ENIGMA working groups. The ENIGMA consortium creates synergy at the intersection of global mental health and clinical neuroscience, and the ENIGMA‐Anxiety Working Group extends the promise of this approach to neuroimaging research on anxiety disorders

    A Tale of Two Type Ia Supernovae: The Fast-declining Siblings SNe 2015bo and 1997cn

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    We thank the anonymous referee for their comments. W.B.H. acknowledges support from the Research Experience for Undergraduates program at the Institute for Astronomy, University of Hawaii-Manoa, funded through NSF grant #2050710. L.G. acknowledges financial support from the Spanish Ministry of Science, Innovation and Universities (MCIN) under the 2019 Ramon y Cajal program RYC2019-027683 and from the Spanish MCIN project HOSTFLOWS PID2020-115253GA-I00. M.G.M., R.G.D., and S.M.T. were funded by the European Union's Horizon 2020 research and innovation program under the Marie Skodowska-Curie grant agreement No. 839090. Based on observations collected at the European Southern Observatory under ESO program 106.2104. The work of the CSP-II has been generously supported by the National Science Foundation under grant Nos. AST-1008343, AST-1613426, AST-1613455, and AST-1613472. The CSP-II was also supported in part by the Danish Agency for Science and Technology and Innovation through a Sapere Aude Level 2 grant. E.B. was partially supported by NASA grant No. 80NSSC20K0538 J.D.L. acknowledges support from a UK Research and Innovation Fellowship (MR/T020784/1). C.R.B. acknowledges support from NSF grant Nos. AST-1008384, AST-1613426, AST-1613455, and AST-1613472. M.S and S.H. are supported by grants from the VILLUM FONDEN (grant No. 28021) and the Independent Research Fund Denmark (IRFD; 8021-00170B).We present optical and near-infrared photometric and spectroscopic observations of the fast-declining Type Ia supernova (SN) 2015bo. SN 2015bo is underluminous (MB=−17.50 ± 0.15 mag) and has a fast-evolving light curve (Δm15(B)=1.91 ± 0.01 mag and sBV=0.48 ± 0.01). It has a unique morphology in the observed V −r color curve, where it is bluer than all other supernovae (SNe) in the comparison sample. A 56Ni mass of 0.17±0.03Me was derived from the peak bolometric luminosity, which is consistent with its location on the luminosity–width relation. Spectroscopically, SN 2015bo is a cool SN in the Branch classification scheme. The velocity evolution measured from spectral features is consistent with 1991bg-like SNe. SN 2015bo has a SN twin (similar spectra) and sibling (same host galaxy), SN 1997cn. Distance moduli of ÎŒ=34.33±0.01 (stat)± 0.11 (sys) mag and ÎŒ=34.34±0.04 (stat)±0.12 (sys) mag are derived for SN 2015bo and SN 1997cn, respectively. These distances are consistent at the 0.06σ level with each other, and they are also consistent with distances derived using surface-brightness fluctuations and redshift-corrected cosmology. This suggests that fast-declining SNe could be accurate distance indicators, which should not be excluded from future cosmological analyses.Research Experience for Undergraduates program at the Institute for Astronomy, University of Hawaii-ManoaNational Science Foundation (NSF) AST-1008384 AST-1613426 AST-1613455 AST-1613472Spanish Ministry of Science, Innovation and Universities (MCIN) RYC2019-027683Spanish MCIN project HOSTFLOWS PID2020-115253GA-I00European Union's Horizon 2020 research and innovation program under the Marie Skodowska-Curie 839090 106.2104National Science Foundation (NSF) AST-1613426 AST-1613455 AST-1613472 AST-1008343Danish Agency for Science and Technology and Innovation through a Sapere Aude Level 2 grantNational Aeronautics & Space Administration (NASA) 80NSSC20K0538UK Research and Innovation Fellowship MR/T020784/1Villum Fonden 28021Independent Research Fund Denmark 8021-00170

    Functional MRI correlates of emotion regulation in major depressive disorder related to depressive disease load measured over nine years

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    Major Depressive Disorder (MDD) often is a recurrent and chronic disorder. We investigated the neurocognitive underpinnings of the incremental risk for poor disease course by exploring relations between enduring depression and brain functioning during regulation of negative and positive emotions using cognitive reappraisal.We used fMRI-data from the longitudinal Netherlands Study of Depression and Anxiety acquired during an emotion regulation task in 77 individuals with MDD. Task-related brain activity was related to disease load, calculated from presence and severity of depression in the preceding nine years. Additionally, we explored task related brain-connectivity. Brain functioning in individuals with MDD was further compared to 35 controls to explore overlap between load-effects and general effects related to MDD history/presence.Disease load was not associated with changes in affect or with brain activity, but with connectivity between areas essential for processing, integrating and regulating emotional information during downregulation of negative emotions. Results did not overlap with general MDD-effects. Instead, MDD was generally associated with lower parietal activity during downregulation of negative emotions. During upregulation of positive emotions, disease load was related to connectivity between limbic regions (although driven by symptomatic state), and connectivity between frontal, insular and thalamic regions was lower in MDD (vs controls).Results suggest that previous depressive load relates to brain connectivity in relevant networks during downregulation of negative emotions. These abnormalities do not overlap with disease-general abnormalities and could foster an incremental vulnerability to recurrence or chronicity of MDD. Therefore, optimizing emotion regulation is a promising therapeutic target for improving long-term MDD course.Pathways through Adolescenc

    Analysis of queries sent to PubMed at the point of care: Observation of search behaviour in a medical teaching hospital

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    Contains fulltext : 69801.pdf ( ) (Open Access)BACKGROUND: The use of PubMed to answer daily medical care questions is limited because it is challenging to retrieve a small set of relevant articles and time is restricted. Knowing what aspects of queries are likely to retrieve relevant articles can increase the effectiveness of PubMed searches. The objectives of our study were to identify queries that are likely to retrieve relevant articles by relating PubMed search techniques and tools to the number of articles retrieved and the selection of articles for further reading. METHODS: This was a prospective observational study of queries regarding patient-related problems sent to PubMed by residents and internists in internal medicine working in an Academic Medical Centre. We analyzed queries, search results, query tools (Mesh, Limits, wildcards, operators), selection of abstract and full-text for further reading, using a portal that mimics PubMed. RESULTS: PubMed was used to solve 1121 patient-related problems, resulting in 3205 distinct queries. Abstracts were viewed in 999 (31%) of these queries, and in 126 (39%) of 321 queries using query tools. The average term count per query was 2.5. Abstracts were selected in more than 40% of queries using four or five terms, increasing to 63% if the use of four or five terms yielded 2-161 articles. CONCLUSION: Queries sent to PubMed by physicians at our hospital during daily medical care contain fewer than three terms. Queries using four to five terms, retrieving less than 161 article titles, are most likely to result in abstract viewing. PubMed search tools are used infrequently by our population and are less effective than the use of four or five terms. Methods to facilitate the formulation of precise queries, using more relevant terms, should be the focus of education and research

    Forearm rotation improves after corrective osteotomy in patients with symptomatic distal radius malunion

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    Objectives: Distal radius malunion can result in pain and functional complaints. One of the functional problems that can affect daily life is impaired forearm rotation. The primary aim of this study was to investigate the effect of corrective osteotomy for distal radius malunion on forearm rotation at 12 months after surgery. We secondarily studied the effect on grip strength, radiological measurements, and patient-reported outcome measurements (PROMs). Patients and methods: This cohort study analysed prospectively collected data of adult patients with symptomatic distal radius malunion. All patients underwent corrective osteotomy for malunion and were followed for 1 year. We measured forearm rotation (pronation and supination) and grip strength and analysed radiographs. PROMs consisted of the Patient-Rated Hand/Wrist Evaluation (PRWHE) questionnaire, Visual Analogue Scale for pain, and satisfaction with hand function. Results:Preoperative total forearm rotation was 112° (SD: 34°), of which supination of 49° (SD: 25°) was more impaired than pronation of 63° (SD: 17°). Twelve months after surgery, an unpaired Student's t-test showed a significant improvement of total forearm rotation to 142° (SD: 17°) (p &lt; 0.05). Pronation improved to 72° (SD: 10°), and supination to 69° (SD: 13°) (p &lt; 0.05). Grip strength, PROMs, as well as inclination and volar tilt on radiographs improved significantly during the first year after surgery (p &lt; 0.05). Conclusion: In patients with reduced forearm rotation due to distal radius malunion, corrective osteotomy is an effective treatment that significantly improves forearm rotation. In addition, this intervention improves grip strength, the PRWHE-score, pain, and satisfaction with hand function.</p

    The effect of paratuberculosis on milk yield—A systematic review and meta-analysis

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    peer-reviewedBovine paratuberculosis is a disease characterized by chronic granulomatous enteritis causing protein-losing enteropathy. Adverse effects on animal productivity are key drivers in the attempt to control paratuberculosis at the farm level. Economic models require an accurate estimation of the production effects associated with paratuberculosis. The aim of this study was to conduct a systematic review and meta-analysis to investigate the effect of paratuberculosis on milk production. A total of 20 effect estimates from 15 studies were included in the final meta-analysis. Substantial between-study heterogeneity was observed. Subgroup analysis by case definition and study design was carried out to investigate heterogeneity. The majority of between-study variation was attributed to studies that defined cases on serology. Calculation of a pooled effect estimate was only appropriate for studies that defined cases by organism detection. A reduction in milk yield, corrected for lactation number and herd of origin of 1.87 kg/d, equivalent to 5.9% of yield, was associated with fecal culture or PCR positivity in individual cows
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