Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.810
Filtrar
Más filtros

Intervalo de año de publicación
1.
Nature ; 576(7786): 232-236, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31802002

RESUMEN

Remote observations of the solar photospheric light scattered by electrons (the K-corona) and dust (the F-corona or zodiacal light) have been made from the ground during eclipses1 and from space at distances as small as 0.3 astronomical units2-5 to the Sun. Previous observations6-8 of dust scattering have not confirmed the existence of the theoretically predicted dust-free zone near the Sun9-11. The transient nature of the corona has been well characterized for large events, but questions still remain (for example, about the initiation of the corona12 and the production of solar energetic particles13) and for small events even its structure is uncertain14. Here we report imaging of the solar corona15 during the first two perihelion passes (0.16-0.25 astronomical units) of the Parker Solar Probe spacecraft13, each lasting ten days. The view from these distances is qualitatively similar to the historical views from ground and space, but there are some notable differences. At short elongations, we observe a decrease in the intensity of the F-coronal intensity, which is suggestive of the long-sought dust free zone9-11. We also resolve the fine-scale plasma structure of very small eruptions, which are frequently ejected from the Sun. These take two forms: the frequently observed magnetic flux ropes12,16 and the predicted, but not yet observed, magnetic islands17,18 arising from the tearing-mode instability in the current sheet. Our observations of the coronal streamer evolution confirm the large-scale topology of the solar corona, but also reveal that, as recently predicted19, streamers are composed of yet smaller substreamers channelling continual density fluctuations at all visible scales.

2.
Cereb Cortex ; 33(6): 2997-3011, 2023 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-35830871

RESUMEN

Research studies based on tractography have revealed a prominent reduction of asymmetry in some key white-matter tracts in schizophrenia (SCZ). However, we know little about the influence of common genetic risk factors for SCZ on the efficiency of routing on structural brain networks (SBNs). Here, we use a novel recall-by-genotype approach, where we sample young adults from a population-based cohort (ALSPAC:N genotyped = 8,365) based on their burden of common SCZ risk alleles as defined by polygenic risk score (PRS). We compared 181 individuals at extremes of low (N = 91) or high (N = 90) SCZ-PRS under a robust diffusion MRI-based graph theoretical SBN framework. We applied a semi-metric analysis revealing higher SMR values for the high SCZ-PRS group compared with the low SCZ-PRS group in the left hemisphere. Furthermore, a hemispheric asymmetry index showed a higher leftward preponderance of indirect connections for the high SCZ-PRS group compared with the low SCZ-PRS group (PFDR < 0.05). These findings might indicate less efficient structural connectivity in the higher genetic risk group. This is the first study in a population-based sample that reveals differences in the efficiency of SBNs associated with common genetic risk variants for SCZ.


Asunto(s)
Esquizofrenia , Adulto Joven , Humanos , Esquizofrenia/diagnóstico por imagen , Esquizofrenia/genética , Predisposición Genética a la Enfermedad/genética , Encéfalo/diagnóstico por imagen , Factores de Riesgo , Genotipo
3.
Artículo en Inglés | MEDLINE | ID: mdl-38777582

RESUMEN

BACKGROUND: Children and young people (CYP) with intellectual and developmental disabilities (IDDs) have significant additional educational needs compared with the general population. In England, the government has established a system of education, health and care plans (EHCPs) to support children with special educational needs and disabilities, but disparities exist between the degree of need and the availability of support. We conducted a prospective UK national cohort study (IMAGINE) of children with rare pathogenic genomic variants, all of which are associated with IDD, to investigate associated neuropsychiatric risk. Subsequently, we obtained information from the UK's National Pupil Database on their educational progress through the state school system. We aimed to identify whether they had received EHCP provision and whether that support was associated with their family's socioeconomic status, region of domicile, ethnicity, sex, primary special educational needs (SEN) type, academic performance and mental health well-being. METHODS: We recruited 2738 CYP from England into the IMAGINE study between 2014 and 2019. The educational histories of the participants (6-28 years old, mean ± standard deviation = 14 ± 4 years, 56% male) were obtained from the Department for Education's National Pupil Database in 2021. Educational data included attainment scores from the Early Year Foundation Stage (<5 years) to key stage 4 (15-16 years). Each family was assigned an index of multiple deprivation (IMD) score based on their home address postcode. Parents or carers rated their child's emotional and behavioural adjustment on the Strengths and Difficulties Questionnaire (SDQ). The association between receiving an EHCP and the child's IMD score, eligibility for free school meals, English region of domicile, ethnicity, sex, primary SEN type, academic attainment and SDQ score was investigated. RESULTS: In this cohort, 78% of participants had received an EHCP. CYP living in the most deprived IMD deciles were substantially less likely to receive EHCP support than those in the least deprived decile, irrespective of their degree of intellectual developmental disability, academic performance or associated mental health problems. There were no sex differences. Children of Asian heritage were more likely to have been granted an EHCP than White children from equivalent IMD deciles. There were striking regional disparities. Participants living in London were significantly more likely to have been awarded an EHCP than participants living anywhere else in England, regardless of their IMD decile; those in the least deprived decile had almost 100% EHCP provision. CONCLUSIONS: This study found evidence for nationwide regional inconsistencies in the awarding of EHCP to CYP with significant intellectual impairments of known genetic aetiology. Disparities in funds available to education authorities could be a contributory factor. EHCP support was potentially influenced by how strongly a parent advocates for their child.

4.
Chaos ; 34(4)2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38587537

RESUMEN

We explore the nonlinear interactions of an optomechanical microresonator driven by two external optical signals. Optical whispering-gallery waves are coupled to acoustic surface waves of a fused silica medium in the equatorial plane of a generic microresonator. The system exhibits coexisting attractors whose behaviors include limit cycles, steady states, tori, quasi-chaos, and fully developed chaos with ghost orbits of a known attractor. Bifurcation diagrams demonstrate the existence of self-similarity, periodic windows, and coexisting attractors and show high-density lines within chaos that suggests a potential ghost orbit. In addition, the Lyapunov spectral components as a function of control parameter illuminate the dynamic nature of attractors and periodic windows with symmetric and asymmetric formations, their domains of existence, their bifurcations, and other nonlinear effects. We show that the power-shift method can access accurately and efficiently attractors in the optomechanical system as it does in other nonlinear systems. To test whether the ghost orbit is the link between two attractors interrupted by chaos, we examine the elements of the bifurcation diagrams as a function of control parameter. We also use detuning as a second control parameter to avoid the chaotic region and clarify that the two attractors are one.

5.
Osteoporos Int ; 34(12): 2027-2045, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37566158

RESUMEN

A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX. INTRODUCTION: The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD). METHODS: We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.5 million person-years. The effect of a prior history of fracture on the risk of any clinical fracture, any osteoporotic fracture, major osteoporotic fracture, and hip fracture alone was examined using an extended Poisson model in each cohort. Covariates examined were age, sex, BMD, and duration of follow-up. The results of the different studies were merged by using the weighted ß-coefficients. RESULTS: A previous fracture history, compared with individuals without a prior fracture, was associated with a significantly increased risk of any clinical fracture (hazard ratio, HR = 1.88; 95% CI = 1.72-2.07). The risk ratio was similar for the outcome of osteoporotic fracture (HR = 1.87; 95% CI = 1.69-2.07), major osteoporotic fracture (HR = 1.83; 95% CI = 1.63-2.06), or for hip fracture (HR = 1.82; 95% CI = 1.62-2.06). There was no significant difference in risk ratio between men and women. Subsequent fracture risk was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any clinical fracture (14%), osteoporotic fracture (17%), and for hip fracture (33%). The risk ratio for all fracture outcomes related to prior fracture decreased significantly with adjustment for age and time since baseline examination. CONCLUSION: A previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by BMD. The effect is similar in men and women. Its quantitation on an international basis permits the more accurate use of this risk factor in case finding strategies.


Asunto(s)
Fracturas de Cadera , Osteoporosis , Fracturas Osteoporóticas , Masculino , Humanos , Femenino , Fracturas Osteoporóticas/etiología , Fracturas Osteoporóticas/complicaciones , Osteoporosis/complicaciones , Fracturas de Cadera/etiología , Fracturas de Cadera/complicaciones , Densidad Ósea , Factores de Riesgo , Medición de Riesgo
6.
Phys Rev Lett ; 131(9): 091801, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37721818

RESUMEN

We measured the nuclear-recoil ionization yield in silicon with a cryogenic phonon-sensitive gram-scale detector. Neutrons from a monoenergetic beam scatter off of the silicon nuclei at angles corresponding to energy depositions from 4 keV down to 100 eV, the lowest energy probed so far. The results show no sign of an ionization production threshold above 100 eV. These results call for further investigation of the ionization yield theory and a comprehensive determination of the detector response function at energies below the keV scale.

7.
Climacteric ; 26(3): 206-215, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37011670

RESUMEN

Endocrine disrupting chemicals are widely distributed in our environment. Humans are exposed to these compounds not only through their occupations, but also through dietary consumption and exposure to contaminated water, personal care products and textiles. Chemicals that are persistent in the body and in our environment include dioxins and polychlorinated biphenyls. Non-persistent chemicals including bisphenol A, phthalates and parabens are equally as important because they are ubiquitous in our environment. Heavy metals, including lead and cadmium, can also have endocrine disrupting properties. Although difficult to study due to their variety of sources of exposures and mechanisms of action, these chemicals have been associated with early menopause, increased frequency of vasomotor symptoms, altered steroid hormone levels and markers of diminished ovarian reserve. Understanding the impacts of these exposures is important given the potential for epigenetic modification, which can alter gene function and result in multi-generational effects. This review summarizes findings in humans and animals or cell-based models from the past decade of research. Continued research is needed to assess the effects of mixtures of chemicals, chronic exposures and new compounds that are continuously being developed as replacements for toxic chemicals that are being phased out.


Asunto(s)
Disruptores Endocrinos , Exposición a Riesgos Ambientales , Humanos , Animales , Femenino , Exposición a Riesgos Ambientales/efectos adversos , Disruptores Endocrinos/toxicidad , Menopausia
8.
Public Health ; 218: 136-138, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37030270

RESUMEN

OBJECTIVES: We determined the age and sociodemographic distribution of COVID-19 cases between January and September 2020 to identify the group with the highest incidence rates at the beginning of the second wave in England. STUDY DESIGN: We undertook a retrospective cohort study design. METHODS: SARS-CoV-2 cases in England were linked with area-level socio-economic status indicators using quintiles of the Index of Multiple Deprivation (IMD). Age-specific incidence rates were stratified by IMD quintile to further assess rates by area-level socio-economic status. RESULTS: Between July and September 2020, SARS-CoV-2 incidence rates were highest amongst those aged 18-21 years, reaching rates of 213.9 (18-19 years) and 143.2 (20-21 years) per 100,000 population by week ending 21 September 2022. Stratification of incidence rates by IMD quintile evidenced that despite high rates observed in the most deprived areas of England amongst the very young and older age groups, the highest rates were observed in the most affluent areas of England amongst the 18- to 21-year-olds. CONCLUSIONS: The reversal of sociodemographic trend in COVID-19 cases in England for those aged 18-21 years at the end of the summer of 2020 and beginning of the second wave showed a novel pattern of COVID-19 risk. For other age groups, the rates remained highest for those from more deprived areas, which highlighted persisting inequalities. Combined, this demonstrates the need to reinforce awareness of COVID-19 risk for young people, particularly given the late inclusion of the 16-17 years age group for vaccination administration, as well as continued efforts to reduce the impact of COVID-19 on vulnerable populations.


Asunto(s)
COVID-19 , Humanos , Anciano , Adolescente , Estudios Retrospectivos , COVID-19/epidemiología , SARS-CoV-2 , Clase Social , Inglaterra/epidemiología
9.
Hum Reprod ; 37(8): 1746-1759, 2022 07 30.
Artículo en Inglés | MEDLINE | ID: mdl-35674312

RESUMEN

STUDY QUESTION: Can an artificial intelligence (AI) model predict human embryo ploidy status using static images captured by optical light microscopy? SUMMARY ANSWER: Results demonstrated predictive accuracy for embryo euploidy and showed a significant correlation between AI score and euploidy rate, based on assessment of images of blastocysts at Day 5 after IVF. WHAT IS KNOWN ALREADY: Euploid embryos displaying the normal human chromosomal complement of 46 chromosomes are preferentially selected for transfer over aneuploid embryos (abnormal complement), as they are associated with improved clinical outcomes. Currently, evaluation of embryo genetic status is most commonly performed by preimplantation genetic testing for aneuploidy (PGT-A), which involves embryo biopsy and genetic testing. The potential for embryo damage during biopsy, and the non-uniform nature of aneuploid cells in mosaic embryos, has prompted investigation of additional, non-invasive, whole embryo methods for evaluation of embryo genetic status. STUDY DESIGN, SIZE, DURATION: A total of 15 192 blastocyst-stage embryo images with associated clinical outcomes were provided by 10 different IVF clinics in the USA, India, Spain and Malaysia. The majority of data were retrospective, with two additional prospectively collected blind datasets provided by IVF clinics using the genetics AI model in clinical practice. Of these images, a total of 5050 images of embryos on Day 5 of in vitro culture were used for the development of the AI model. These Day 5 images were provided for 2438 consecutively treated women who had undergone IVF procedures in the USA between 2011 and 2020. The remaining images were used for evaluation of performance in different settings, or otherwise excluded for not matching the inclusion criteria. PARTICIPANTS/MATERIALS, SETTING, METHODS: The genetics AI model was trained using static 2-dimensional optical light microscope images of Day 5 blastocysts with linked genetic metadata obtained from PGT-A. The endpoint was ploidy status (euploid or aneuploid) based on PGT-A results. Predictive accuracy was determined by evaluating sensitivity (correct prediction of euploid), specificity (correct prediction of aneuploid) and overall accuracy. The Matthew correlation coefficient and receiver-operating characteristic curves and precision-recall curves (including AUC values), were also determined. Performance was also evaluated using correlation analyses and simulated cohort studies to evaluate ranking ability for euploid enrichment. MAIN RESULTS AND THE ROLE OF CHANCE: Overall accuracy for the prediction of euploidy on a blind test dataset was 65.3%, with a sensitivity of 74.6%. When the blind test dataset was cleansed of poor quality and mislabeled images, overall accuracy increased to 77.4%. This performance may be relevant to clinical situations where confounding factors, such as variability in PGT-A testing, have been accounted for. There was a significant positive correlation between AI score and the proportion of euploid embryos, with very high scoring embryos (9.0-10.0) twice as likely to be euploid than the lowest-scoring embryos (0.0-2.4). When using the genetics AI model to rank embryos in a cohort, the probability of the top-ranked embryo being euploid was 82.4%, which was 26.4% more effective than using random ranking, and ∼13-19% more effective than using the Gardner score. The probability increased to 97.0% when considering the likelihood of one of the top two ranked embryos being euploid, and the probability of both top two ranked embryos being euploid was 66.4%. Additional analyses showed that the AI model generalized well to different patient demographics and could also be used for the evaluation of Day 6 embryos and for images taken using multiple time-lapse systems. Results suggested that the AI model could potentially be used to differentiate mosaic embryos based on the level of mosaicism. LIMITATIONS, REASONS FOR CAUTION: While the current investigation was performed using both retrospectively and prospectively collected data, it will be important to continue to evaluate real-world use of the genetics AI model. The endpoint described was euploidy based on the clinical outcome of PGT-A results only, so predictive accuracy for genetic status in utero or at birth was not evaluated. Rebiopsy studies of embryos using a range of PGT-A methods indicated a degree of variability in PGT-A results, which must be considered when interpreting the performance of the AI model. WIDER IMPLICATIONS OF THE FINDINGS: These findings collectively support the use of this genetics AI model for the evaluation of embryo ploidy status in a clinical setting. Results can be used to aid in prioritizing and enriching for embryos that are likely to be euploid for multiple clinical purposes, including selection for transfer in the absence of alternative genetic testing methods, selection for cryopreservation for future use or selection for further confirmatory PGT-A testing, as required. STUDY FUNDING/COMPETING INTEREST(S): Life Whisperer Diagnostics is a wholly owned subsidiary of the parent company, Presagen Holdings Pty Ltd. Funding for the study was provided by Presagen with grant funding received from the South Australian Government: Research, Commercialisation, and Startup Fund (RCSF). 'In kind' support and embryology expertise to guide algorithm development were provided by Ovation Fertility. 'In kind' support in terms of computational resources provided through the Amazon Web Services (AWS) Activate Program. J.M.M.H., D.P. and M.P. are co-owners of Life Whisperer and Presagen. S.M.D., M.A.D. and T.V.N. are employees or former employees of Life Whisperer. S.M.D, J.M.M.H, M.A.D, T.V.N., D.P. and M.P. are listed as inventors of patents relating to this work, and also have stock options in the parent company Presagen. M.V. sits on the advisory board for the global distributor of the technology described in this study and also received support for attending meetings. TRIAL REGISTRATION NUMBER: N/A.


Asunto(s)
Diagnóstico Preimplantación , Aneuploidia , Inteligencia Artificial , Australia , Blastocisto/patología , Femenino , Fertilización In Vitro/métodos , Humanos , Embarazo , Diagnóstico Preimplantación/métodos , Probabilidad , Estudios Retrospectivos
10.
Osteoporos Int ; 33(10): 2103-2136, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35639106

RESUMEN

We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. INTRODUCTION: The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide. The aim of this study is to determine whether the current algorithms can be further optimised with respect to current and novel risk factors. METHODS: A computerised literature search was performed in PubMed from inception until May 17, 2019, to identify eligible cohorts for updating the FRAX coefficients. Additionally, we searched the abstracts of conference proceedings of the American Society for Bone and Mineral Research, European Calcified Tissue Society and World Congress of Osteoporosis. Prospective cohort studies with data on baseline clinical risk factors and incident fractures were eligible. RESULTS: Of the 836 records retrieved, 53 were selected for full-text assessment after screening on title and abstract. Twelve cohorts were deemed eligible and of these, 4 novel cohorts were identified. These cohorts, together with 60 previously identified cohorts, will provide the resource for constructing an updated version of FRAX comprising 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. For each known and candidate risk factor, multivariate hazard functions for hip fracture, major osteoporotic fracture and death will be tested using extended Poisson regression. Sex- and/or ethnicity-specific differences in the weights of the risk factors will be investigated. After meta-analyses of the cohort-specific beta coefficients for each risk factor, models comprising 10-year probability of hip and major osteoporotic fracture, with or without femoral neck bone mineral density, will be computed. CONCLUSIONS: These assembled cohorts and described models will provide the framework for an updated FRAX tool enabling enhanced assessment of fracture risk (PROSPERO (CRD42021227266)).


Asunto(s)
Fracturas de Cadera , Osteoporosis , Fracturas Osteoporóticas , Densidad Ósea , Fracturas de Cadera/complicaciones , Fracturas de Cadera/etiología , Humanos , Osteoporosis/complicaciones , Osteoporosis/epidemiología , Fracturas Osteoporóticas/epidemiología , Fracturas Osteoporóticas/etiología , Estudios Prospectivos , Medición de Riesgo/métodos , Factores de Riesgo
11.
J Immunol ; 205(4): 957-967, 2020 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-32641388

RESUMEN

Metabolic reprogramming plays a central role in T cell activation and differentiation, and the inhibition of key metabolic pathways in activated T cells represents a logical approach for the development of new therapeutic agents for treating autoimmune diseases. The widely prescribed antidiabetic drug metformin and the glycolytic inhibitor 2-deoxyglucose (2-DG) have been used to study the inhibition of oxidative phosphorylation and glycolysis, respectively, in murine immune cells. Published studies have demonstrated that combination treatment with metformin and 2-DG was efficacious in dampening mouse T cell activation-induced effector processes, relative to treatments with either metformin or 2-DG alone. In this study, we report that metformin + 2-DG treatment more potently suppressed IFN-γ production and cell proliferation in activated primary human CD4+ T cells than either metformin or 2-DG treatment alone. The effects of metformin + 2-DG on human T cells were accompanied by significant remodeling of activation-induced metabolic transcriptional programs, in part because of suppression of key transcriptional regulators MYC and HIF-1A. Accordingly, metformin + 2-DG treatment significantly suppressed MYC-dependent metabolic genes and processes, but this effect was found to be independent of mTORC1 signaling. These findings reveal significant insights into the effects of metabolic inhibition by metformin + 2-DG treatment on primary human T cells and provide a basis for future work aimed at developing new combination therapy regimens that target multiple pathways within the metabolic networks of activated human T cells.


Asunto(s)
Linfocitos T CD4-Positivos/efectos de los fármacos , Desoxiglucosa/farmacología , Redes y Vías Metabólicas/efectos de los fármacos , Metformina/farmacología , Animales , Linfocitos T CD4-Positivos/metabolismo , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Glucólisis/efectos de los fármacos , Humanos , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Ratones , Fosforilación Oxidativa/efectos de los fármacos , Transducción de Señal/efectos de los fármacos
12.
Public Health ; 211: 85-87, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36058199

RESUMEN

OBJECTIVE: To determine whether household contacts of confirmed cases of COVID-19 have an increased risk of hospitalisation or death. METHODS: We used the HOSTED data set of index cases of COVID-19 in England between June and November 2020, linked to Secondary Uses Service data on hospital episodes and Office for National Statistics' mortality data. Multivariable logistic regression models of the odds of household contacts being hospitalised or dying within six weeks of an index case, adjusted for case type, age, sex and calendar month were calculated. Excess risk was determined by comparing the first six weeks after the index case with 6-12 weeks after the index case in a survival analysis framework. RESULTS: Index cases were more likely to be hospitalised or die than either secondary cases or non-cases, having adjusted for age and sex. There was an increased risk of hospitalisation for non-cases (adjusted hazard ratio (aHR) 1.10; 95% confidence interval (CI) 1.04, 1.16) and of death (aHR 1.57; 95% CI 1.14, 2.16) in the first six weeks after an index case, compared to 6-12 weeks after. CONCLUSION: Risks of hospitalisation and mortality are predictably higher in cases compared to non-cases. The short-term increase in risks for non-case contacts following diagnosis of the index case may suggest incomplete case ascertainment among contacts, although this was relatively small.


Asunto(s)
COVID-19 , Composición Familiar , Hospitalización , Humanos , Modelos Logísticos , SARS-CoV-2
13.
Phys Rev Lett ; 126(2): 021803, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33512206

RESUMEN

Sterile neutrinos are natural extensions to the standard model of particle physics and provide a possible portal to the dark sector. We report a new search for the existence of sub-MeV sterile neutrinos using the decay-momentum reconstruction technique in the decay of ^{7}Be. The experiment measures the total energy of the ^{7}Li daughter atom from the electron capture decay of ^{7}Be implanted into sensitive superconducting tunnel junction (STJ) quantum sensors. This first experiment presents data from a single STJ operated at a low count rate for a net total of 28 days, and provides exclusion limits on sterile neutrinos in the mass range from 100 to 850 keV that improve upon previous work by up to an order of magnitude.

14.
BJOG ; 128(13): 2116-2125, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34407281

RESUMEN

OBJECTIVE: To explore the experiences of women who had used an Early Pregnancy Assessment Unit (EPAU) service in the UK and make recommendations for their improvement. DESIGN: Qualitative interview study. SETTING: Early Pregnancy Assessment Units in the UK. SAMPLE: A maximum variation sample of women who had consented to be interviewed having attended one of 26 EPAUs involved in the VESPA study in 2018. METHODS: In-depth telephone interviews with 38 women. A thematic framework analysis was conducted, with a focus on how experiences varied according to EPAU service configuration and clinical pathway. MAIN OUTCOME MEASURES: Women's experiences of EPAU services. RESULTS: We found that EPAUs are highly valued, and women's experiences were generally positive. However, women reported a range of issues that negatively affected their experience. These included difficulties accessing the service, insensitive management of the investigation and treatment options of pregnancy loss, poor communication, insufficient information and a lack of support for their psychological health. These issues were not strongly associated with EPAU configuration or clinical pathway. CONCLUSIONS: Recommendations to improve women's experiences include the separation of EPAUs from general maternity services, and we make suggestions on how to remove barriers to access by reviewing opening hours, how to provide sensitive patient management, such as automatically cancelling appointments and scans following pregnancy loss, and how to improve communication, both with women and their partners as well as with other parts of the health service. TWEETABLE ABSTRACT: Early Pregnancy Assessment Units are highly valued by women but aspects of their care experiences, particularly around sensitive management of pregnancy loss, could be improved.


Asunto(s)
Accesibilidad a los Servicios de Salud , Servicios de Salud Materna/organización & administración , Satisfacción del Paciente , Mujeres Embarazadas/psicología , Aborto Inducido , Aborto Espontáneo , Adulto , Femenino , Humanos , Entrevistas como Asunto , Embarazo , Investigación Cualitativa , Reino Unido , Adulto Joven
15.
Ultrasound Obstet Gynecol ; 57(3): 488-492, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32672377

RESUMEN

OBJECTIVES: Intact urethral support and normal sphincter function are deemed important for urinary continence. We aimed to test whether the location of urethral kinking (as the probable anatomical correlate of maximal pressure transmission) is associated with stress urinary incontinence and/or urodynamic stress incontinence. METHODS: This was a retrospective study of women seen at a tertiary urogynecological center in 2017. Patients had undergone an interview, multichannel urodynamic testing and four-dimensional translabial ultrasound examination. Those with a history of anti-incontinence surgery, absence of urethral kinking on ultrasound and/or missing or inadequate ultrasound volume data were excluded. Volume data were used to assess urethral mobility using a semi-automated Excel® urethral motion profile program. Mobility vectors were calculated using the formula √((x valsalva - x rest )2 + (y valsalva - y rest )2 ), where x and y are the coordinates of six equidistant points along the length of the urethra from the bladder neck to the external urethral meatus. The location of urethral kinking was identified as a concave contour of the urethra on the vaginal side in the midsagittal plane on maximum Valsalva maneuver. The distance between the center of the kink and the bladder neck was measured and expressed as a centile in relation to the total length of the urethra, using the formula: (distance from bladder neck/total length of urethra) × 100. Univariate and multivariate analyses were performed to test the associations of stress urinary incontinence and urodynamic stress incontinence with age, maximum urethral pressure, urethral mobility vectors and location of urethral kinking. RESULTS: Of 450 women seen during the study period, 61 were excluded owing to previous incontinence surgery and 82 owing to absence of urethral kinking, inadequate volume data or missing data, leaving 307 women included, of whom 227 (74%) complained of stress urinary incontinence and 211 (69%) complained of urgency urinary incontinence. 190 (62%) of the women were diagnosed with urodynamic stress incontinence. On multivariate analysis, maximum urethral pressure (36 vs 50 cmH2 O; P < 0.001), mid-urethral mobility (2.27 vs 2.03 cm; P = 0.003) and location of urethral kinking (63.1st vs 59.7th centile; P = 0.002) were associated significantly with urodynamic stress incontinence. The location of urethral kinking was associated with stress urinary incontinence on univariate analysis (P = 0.026) but not on multivariate analysis (P = 0.21). CONCLUSIONS: The location of urethral kinking is associated with urodynamic stress incontinence. The further urethral kinking is from the mid urethra, the more likely is urodynamic stress incontinence. This provides circumstantial evidence for the pressure-transmission theory of stress urinary continence. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Ultrasonografía , Incontinencia Urinaria de Esfuerzo/diagnóstico por imagen , Incontinencia Urinaria de Esfuerzo/fisiopatología , Incontinencia Urinaria/diagnóstico por imagen , Incontinencia Urinaria/fisiopatología , Anciano , Diagnóstico Diferencial , Femenino , Humanos , Persona de Mediana Edad , Presión , Estudios Retrospectivos , Ultrasonografía/métodos , Uretra/diagnóstico por imagen , Uretra/fisiopatología , Vejiga Urinaria/diagnóstico por imagen , Urodinámica , Vagina/patología , Maniobra de Valsalva , Vulva/diagnóstico por imagen
16.
J Appl Microbiol ; 131(2): 855-872, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33098196

RESUMEN

AIMS: Existing methods for the identification of the subspecies of Xylella fastidiosa are time-consuming which can lead to delays in diagnosis and the associated plant health response to outbreaks and interceptions. METHODS AND RESULTS: Diagnostic markers were identified using a comparative genomics approach to allow fine differentiation of the very closely related subspecies. Five qPCR assays were designed to allow specific detection of X. fastidiosa subsp. fastidiosa, X. fastidiosa subsp. multiplex, X. fastidiosa subsp. pauca, X. fastidiosa subsp. morus and X. fastidiosa subsp. sandyi. All assays were validated according to the European and Mediterranean Plant Protection Organisation (EPPO) standard PM7/98(2). CONCLUSIONS: All of the assays were shown to be specific to the target subspecies and all the assays could be used to detect femtogram quantities of X. fastidiosa DNA. SIGNIFICANCE AND IMPACT OF THE STUDY: At present, diagnosing the subspecies of X. fastidiosa requires multiple conventional PCR assays (although only available for three of the five subspecies) or multi-locus sequence typing which takes several days. By comparison, the new assays provide a substantial reduction in the turnaround time for direct identification to the subspecies level in as little as 75 min.


Asunto(s)
Genómica , Enfermedades de las Plantas , Reacción en Cadena en Tiempo Real de la Polimerasa , Xylella/clasificación , ADN Bacteriano/genética , Tipificación de Secuencias Multilocus , Enfermedades de las Plantas/microbiología
17.
Chaos ; 31(1): 013120, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33754793

RESUMEN

Coexisting attractors are studied in a single-mode coherent model of a laser with an injected signal. We report that every attractor has a unique Lyapunov exponent (LE) pattern that is choreographed by the subtle variations in the attractor's dynamics and circumscribed by a common Lyapunov spectral pattern that begins and ends with two-zero LEs. Lyapunov spectra form symmetric-like and asymmetric bubbles; the former foreshadows an attractor's proximity to the cusp of an eminent change in dynamics and the latter indicates the presence of a bifurcation. We show that the peak values of the asymmetric bubbles are always associated with two-zero LEs; in fact, they are allied inseparably in forecasting period-doubling episodes. The two-zero LEs' predictor of torus dynamics is refined to include the convergence of three LEs to a triplet of zeros as a precursor to the two-zero spectra. We report that the long-standing two-zero LEs' signature is a necessary but not sufficient condition for predicting attractors and their dynamic conditions. The evolution of the attractor volume as a function of the injected signal is compared to the spectral formation of the attractor; we report slope changes and points of inflections in the volume trajectory where spectral changes indicate dynamic changes. Attractor viability is tested preliminarily by including random low-level noise in the frequency of the injected signal.

18.
Health Soc Work ; 46(1): 33-41, 2021 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-33637978

RESUMEN

Recent investigations have elucidated the influence of the strong Black woman (SBW) ideal on the mental health and treatment-seeking behaviors of Black women in the United States. However, factors related to how the SBW ideal affects Black women's positive and negative attitudes toward seeking professional psychological help have yet to be identified. The current study fills this void in the literature through a qualitative examination of how the SBW ideal affects Black women's mental health utilization. Analyses were based on 62 participants, including college students and community members, ranging in age from 18 to 72 years. The present study advances the idea that endorsement of the SBW ideal affects Black women's mental utilization. These results offer evidence and clarification of the impact of the SBW ideal on Black women's mental health and identity-specific points of intervention for mental health practitioners conducting therapeutic work with Black women. Authors provide practice recommendations for practitioners and suggestions for future research.


Asunto(s)
Negro o Afroamericano , Salud Mental , Adolescente , Adulto , Anciano , Femenino , Humanos , Persona de Mediana Edad , Investigación Cualitativa , Estados Unidos , Salud de la Mujer , Adulto Joven
19.
Artículo en Inglés | MEDLINE | ID: mdl-32015038

RESUMEN

Pseudomonas aeruginosa is an opportunistic pathogen that is inherently resistant to many antibiotics and represents an increasing threat due to the emergence of drug-resistant strains. There is a pressing need to develop innovative antimicrobials against this pathogen. In this study, we identified the O-specific antigen (OSA) of P. aeruginosa serotype O6 as a novel target for therapeutic intervention. Binding of monoclonal antibodies and antigen-binding fragments therefrom to O6 OSA leads to rapid outer membrane destabilization and inhibition of cell growth. The antimicrobial effect correlated directly with antibody affinity. Antibody binding to the O antigen of a second lipopolysaccharide (LPS) type present in P. aeruginosa or to the LPS core did not affect cell viability. Atomic force microscopy showed that antibody binding to OSA resulted in early flagellum loss, formation of membrane blebs, and eventually complete outer membrane loss. We hypothesize that antibody binding to OSA disrupts a key interaction in the P. aeruginosa outer membrane.


Asunto(s)
Anticuerpos Antibacterianos/inmunología , Anticuerpos Monoclonales/inmunología , Membrana Externa Bacteriana/patología , Antígenos O/inmunología , Pseudomonas aeruginosa/inmunología , Afinidad de Anticuerpos/inmunología , Flagelos/fisiología , Lipopolisacáridos/inmunología , Microscopía de Fuerza Atómica , Infecciones por Pseudomonas/inmunología , Pseudomonas aeruginosa/crecimiento & desarrollo
20.
Hum Reprod ; 35(4): 770-784, 2020 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-32240301

RESUMEN

STUDY QUESTION: Can an artificial intelligence (AI)-based model predict human embryo viability using images captured by optical light microscopy? SUMMARY ANSWER: We have combined computer vision image processing methods and deep learning techniques to create the non-invasive Life Whisperer AI model for robust prediction of embryo viability, as measured by clinical pregnancy outcome, using single static images of Day 5 blastocysts obtained from standard optical light microscope systems. WHAT IS KNOWN ALREADY: Embryo selection following IVF is a critical factor in determining the success of ensuing pregnancy. Traditional morphokinetic grading by trained embryologists can be subjective and variable, and other complementary techniques, such as time-lapse imaging, require costly equipment and have not reliably demonstrated predictive ability for the endpoint of clinical pregnancy. AI methods are being investigated as a promising means for improving embryo selection and predicting implantation and pregnancy outcomes. STUDY DESIGN, SIZE, DURATION: These studies involved analysis of retrospectively collected data including standard optical light microscope images and clinical outcomes of 8886 embryos from 11 different IVF clinics, across three different countries, between 2011 and 2018. PARTICIPANTS/MATERIALS, SETTING, METHODS: The AI-based model was trained using static two-dimensional optical light microscope images with known clinical pregnancy outcome as measured by fetal heartbeat to provide a confidence score for prediction of pregnancy. Predictive accuracy was determined by evaluating sensitivity, specificity and overall weighted accuracy, and was visualized using histograms of the distributions of predictions. Comparison to embryologists' predictive accuracy was performed using a binary classification approach and a 5-band ranking comparison. MAIN RESULTS AND THE ROLE OF CHANCE: The Life Whisperer AI model showed a sensitivity of 70.1% for viable embryos while maintaining a specificity of 60.5% for non-viable embryos across three independent blind test sets from different clinics. The weighted overall accuracy in each blind test set was >63%, with a combined accuracy of 64.3% across both viable and non-viable embryos, demonstrating model robustness and generalizability beyond the result expected from chance. Distributions of predictions showed clear separation of correctly and incorrectly classified embryos. Binary comparison of viable/non-viable embryo classification demonstrated an improvement of 24.7% over embryologists' accuracy (P = 0.047, n = 2, Student's t test), and 5-band ranking comparison demonstrated an improvement of 42.0% over embryologists (P = 0.028, n = 2, Student's t test). LIMITATIONS, REASONS FOR CAUTION: The AI model developed here is limited to analysis of Day 5 embryos; therefore, further evaluation or modification of the model is needed to incorporate information from different time points. The endpoint described is clinical pregnancy as measured by fetal heartbeat, and this does not indicate the probability of live birth. The current investigation was performed with retrospectively collected data, and hence it will be of importance to collect data prospectively to assess real-world use of the AI model. WIDER IMPLICATIONS OF THE FINDINGS: These studies demonstrated an improved predictive ability for evaluation of embryo viability when compared with embryologists' traditional morphokinetic grading methods. The superior accuracy of the Life Whisperer AI model could lead to improved pregnancy success rates in IVF when used in a clinical setting. It could also potentially assist in standardization of embryo selection methods across multiple clinical environments, while eliminating the need for complex time-lapse imaging equipment. Finally, the cloud-based software application used to apply the Life Whisperer AI model in clinical practice makes it broadly applicable and globally scalable to IVF clinics worldwide. STUDY FUNDING/COMPETING INTEREST(S): Life Whisperer Diagnostics, Pty Ltd is a wholly owned subsidiary of the parent company, Presagen Pty Ltd. Funding for the study was provided by Presagen with grant funding received from the South Australian Government: Research, Commercialisation and Startup Fund (RCSF). 'In kind' support and embryology expertise to guide algorithm development were provided by Ovation Fertility. J.M.M.H., D.P. and M.P. are co-owners of Life Whisperer and Presagen. Presagen has filed a provisional patent for the technology described in this manuscript (52985P pending). A.P.M. owns stock in Life Whisperer, and S.M.D., A.J., T.N. and A.P.M. are employees of Life Whisperer.


Asunto(s)
Inteligencia Artificial , Microscopía , Australia , Femenino , Fertilización In Vitro , Humanos , Embarazo , Estudios Retrospectivos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA