37 research outputs found

    Comments on Exclusive Electroproduction of Transversely Polarized Vector Mesons

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    We discuss the electroproduction of light vector mesons from transversely polarized photons. Here QCD factorization cannot be applied as shown explicitly in a leading order calculation of corresponding Feynman diagrams. It is emphasized that present infrared singular contributions cannot be regularized through phenomenological meson distribution amplitudes with suppressed endpoint configurations. We point out that infrared divergencies arise also from integrals over skewed parton distributions of the nucleons. In a phenomenological analysis of transverse vector meson production model dependent regularizations have to be applied. If this procedure preserves the analytic structure suggested by a leading order calculation of Feynman diagrams, one obtains contributions from nucleon parton distributions and their derivatives. In particular polarized gluons enter only through their derivative

    Off-Forward Parton Distributions

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    Recently, there have been some interesting developments involving off-forward parton distributions of the nucleon, deeply virtual Compton scattering, and hard diffractive vector-meson production. These developments are triggered by the realization that the off-forward distributions contain information about the internal spin structure of the nucleon and that diffractive electroproduction of vector mesons depends on these unconventional distributions. This paper gives a brief overview of the recent developments

    Shared decision‐making and maternity care in the deep learning age: Acknowledging and overcoming inherited defeaters

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    In recent years there has been an explosion of interest in Artificial Intelligence (AI) both in health care and academic philosophy. This has been due mainly to the rise of effective machine learning and deep learning algorithms, together with increases in data collection and processing power, which have made rapid progress in many areas. However, use of this technology has brought with it philosophical issues and practical problems, in particular, epistemic and ethical. In this paper the authors, with backgrounds in philosophy, maternity care practice and clinical research, draw upon and extend a recent framework for shared decision‐making (SDM) that identified a duty of care to the client's knowledge as a necessary condition for SDM. This duty entails the responsibility to acknowledge and overcome epistemic defeaters. This framework is applied to the use of AI in maternity care, in particular, the use of machine learning and deep learning technology to attempt to enhance electronic fetal monitoring (EFM). In doing so, various sub‐kinds of epistemic defeater, namely, transparent, opaque, underdetermined, and inherited defeaters are taxonomized and discussed. The authors argue that, although effective current or future AI‐enhanced EFM may impose an epistemic obligation on the part of clinicians to rely on such systems' predictions or diagnoses as input to SDM, such obligations may be overridden by inherited defeaters, caused by a form of algorithmic bias. The existence of inherited defeaters implies that the duty of care to the client's knowledge extends to any situation in which a clinician (or anyone else) is involved in producing training data for a system that will be used in SDM. Any future AI must be capable of assessing women individually, taking into account a wide range of factors including women's preferences, to provide a holistic range of evidence for clinical decision‐making

    The Spin Structure of the Nucleon

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    We present an overview of recent experimental and theoretical advances in our understanding of the spin structure of protons and neutrons.Comment: 84 pages, 29 figure

    Evolutionary patterns of two major reproduction candidate genes (Zp2 and Zp3) reveal no contribution to reproductive isolation between bovine species

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    <p>Abstract</p> <p>Background</p> <p>It has been established that mammalian egg zona pellucida (ZP) glycoproteins are responsible for species-restricted binding of sperm to unfertilized eggs, inducing the sperm acrosome reaction, and preventing polyspermy. In mammals, ZP apparently represents a barrier to heterospecific fertilization and thus probably contributes to reproductive isolation between species. The evolutionary relationships between some members of the tribe Bovini are complex and highly debatable, particularly, those involving <it>Bos </it>and <it>Bison </it>species for which interspecific hybridization is extensively documented. Because reproductive isolation is known to be a major precursor of species divergence, testing evolutionary patterns of ZP glycoproteins may shed some light into the speciation process of these species. To this end, we have examined intraspecific and interspecific genetic variation of two ZP genes (<it>Zp2 </it>and <it>Zp3</it>) for seven representative species (111 individuals) from the Bovini tribe, including five species from <it>Bos </it>and <it>Bison</it>, and two species each from genera <it>Bubalus </it>and <it>Syncerus</it>.</p> <p>Results</p> <p>A pattern of low levels of intraspecific polymorphism and interspecific divergence was detected for the two sequenced fragments each for <it>Zp2 </it>and <it>Zp3</it>. At intraspecific level, none of neutrality tests detected deviations from neutral equilibrium expectations for the two genes. Several haplotypes in both genes were shared by multiple species from <it>Bos </it>and <it>Bison</it>.</p> <p>Conclusions</p> <p>Here we argue that neither ancestral polymorphism nor introgressive hybridization alone can fully account for haplotype sharing among species from <it>Bos </it>and <it>Bison</it>, and that both scenarios have contributed to such a pattern of haplotype sharing observed here. Additionally, codon-based tests revealed strong evidence for purifying selection in the <it>Zp3 </it>coding haplotype sequences and weak evidence for purifying selection in the <it>Zp2 </it>coding haplotype sequences. Contrary to a general genetic pattern that genes or genomic regions contributing to reproductive isolation between species often evolve rapidly and show little or no gene flow between species, these results demonstrate that, particularly, those sequenced exons of the <it>Zp2 </it>and the <it>Zp3 </it>did not show any contribution to reproductive isolation between the bovine species studied here.</p

    Assessing Physical Activity in People With Mental Illness: 23-country Reliability and Validity of the Simple Physical Activity Questionnaire (SIMPAQ)

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    Background: Physical inactivity is a key contributor to the global burden of disease and disproportionately impacts the wellbeing of people experiencing mental illness. Increases in physical activity are associated with improvements in symptoms of mental illness and reduction in cardiometabolic risk. Reliable and valid clinical tools that assess physical activity would improve evaluation of intervention studies that aim to increase physical activity and reduce sedentary behaviour in people living with mental illness. Methods: The five-item Simple Physical Activity Questionnaire (SIMPAQ) was developed by a multidisciplinary, international working group as a clinical tool to assess physical activity and sedentary behaviour in people living with mental illness. Patients with a DSM or ICD mental illness diagnoses were recruited and completed the SIMPAQ on two occasions, one week apart. Participants wore an Actigraph accelerometer and completed brief cognitive and clinical assessments. Results: Evidence of SIMPAQ validity was assessed against accelerometer-derived measures of physical activity. Data were obtained from 1010 participants. The SIMPAQ had good test-retest reliability. Correlations for moderate-vigorous physical activity was comparable to studies conducted in general population samples. Evidence of validity for the sedentary behaviour item was poor. An alternative method to calculate sedentary behaviour had stronger evidence of validity. This alternative method is recommended for use in future studies employing the SIMPAQ. Conclusions: The SIMPAQ is a brief measure of physical activity and sedentary behaviour that can be reliably and validly administered by health professionals.Universidad Pablo de Olavide de Sevilla. Departamento de Deporte e InformĂĄtic

    Target and double spin asymmetries of deeply virtual pi(0) production with a longitudinally polarized proton target and CLAS

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    The target and double spin asymmetries of the exclusive pseudoscalar channel e⃗p⃗→epπ0\vec e\vec p\to ep\pi^0 were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized proton target at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS). The data were collected over a large kinematic phase space and divided into 110 four-dimensional bins of Q2Q^2, xBx_B, −t-t and ϕ\phi. Large values of asymmetry moments clearly indicate a substantial contribution to the polarized structure functions from transverse virtual photon amplitudes. The interpretation of experimental data in terms of generalized parton distributions (GPDs) provides the first insight on the chiral-odd GPDs H~T\tilde{H}_T and ETE_T, and complement previous measurements of unpolarized structure functions sensitive to the GPDs HTH_T and EˉT\bar E_T. These data provide necessary constraints for chiral-odd GPD parametrizations and will strongly influence existing theoretical handbag models

    A core outcome set for pre‐eclampsia research: an international consensus development study

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    Objective To develop a core outcome set for pre‐eclampsia. Design Consensus development study. Setting International. Population Two hundred and eight‐one healthcare professionals, 41 researchers and 110 patients, representing 56 countries, participated. Methods Modified Delphi method and Modified Nominal Group Technique. Results A long‐list of 116 potential core outcomes was developed by combining the outcomes reported in 79 pre‐eclampsia trials with those derived from thematic analysis of 30 in‐depth interviews of women with lived experience of pre‐eclampsia. Forty‐seven consensus outcomes were identified from the Delphi process following which 14 maternal and eight offspring core outcomes were agreed at the consensus development meeting. Maternal core outcomes: death, eclampsia, stroke, cortical blindness, retinal detachment, pulmonary oedema, acute kidney injury, liver haematoma or rupture, abruption, postpartum haemorrhage, raised liver enzymes, low platelets, admission to intensive care required, and intubation and ventilation. Offspring core outcomes: stillbirth, gestational age at delivery, birthweight, small‐for‐gestational‐age, neonatal mortality, seizures, admission to neonatal unit required and respiratory support. Conclusions The core outcome set for pre‐eclampsia should underpin future randomised trials and systematic reviews. Such implementation should ensure that future research holds the necessary reach and relevance to inform clinical practice, enhance women's care and improve the outcomes of pregnant women and their babies

    Pregnant Women&rsquo;s Experiences with Midwifery-Led Antenatal Care Services in Peri-Urban Communities in Karachi, Pakistan

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    Nida Salman Yazdani,1 Kaniz Amna Haider,2 Amna Khan,2 Syed Ali Jaffar Zaidi,2 Akbar Rajani,1 Imran Nisar,2 Fyezah Jehan,2 Zahra Hoodbhoy2 1Research and Programs, VITAL Pakistan Trust, Karachi, Pakistan; 2Department of Paediatrics and Child Health, the Aga Khan University, Karachi, PakistanCorrespondence: Zahra Hoodbhoy, Aga Khan University, Stadium Road PO Box 3500, Karachi, 74800, Pakistan, Tel +92-3343481179, Email [email protected]: To understand pregnant women’s experience with midwifery-led antenatal care services using the Respectful Maternity Care charter in primary health centers in Karachi, Pakistan.Methods: This cross-sectional study was at Rehri Goth and Ibrahim Hyderi, two peri-urban communities in Karachi, Pakistan, where women receive antenatal care services. All pregnant women in their third trimester who consented during the study period were included. The participants were asked about access to care, antenatal care experience, person-centered approach, and general satisfaction with the facility using a pre-designed questionnaire. These themes were mapped onto the universal Respectful Maternity Care charter. Descriptive statistics were used to summarize the findings in each of these themes. Multivariable logistic regression techniques to determine the relationship between the dependent and independent variables.Results: There were 904 women who agreed to participate in this study during January to December 2021. Majority of the women (94%, n=854) were satisfied with the operating hours and cleanliness. More than 90% of the women reported positive experiences regarding privacy, respectful treatment by midwives, and non-discriminatory care. However, 40% (n=362) of the women reported not receiving adequate information and informed consent before a medical procedure, while 65% (n=587) reported poor counseling for birth preparedness. Maternal age, women’s occupation, women’s education, and parity were found to be significantly associated with respect provided, satisfaction with counseling and the consent process.Conclusion: This study reported satisfaction of pregnant women with the facility’s ambiance, respect, and care; however, poor communication skills regarding consent and antenatal counseling were reported. The findings suggest the need for more efficient strategies, such as regular respectful maternity care and technical training to strengthen midwife-patient interactions and enhance overall satisfaction, thus improving maternal and newborn outcomes.Keywords: antenatal care, patient satisfaction, Respectful Maternity Care, Pakista
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