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1.
Mol Ecol ; 33(1): e17199, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38018020

RESUMO

Identifying genetic conservation units (CUs) in threatened species is critical for the preservation of adaptive capacity and evolutionary potential in the face of climate change. However, delineating CUs in highly mobile species remains a challenge due to high rates of gene flow and genetic signatures of isolation by distance. Even when CUs are delineated in highly mobile species, the CUs often lack key biological information about what populations have the most conservation need to guide management decisions. Here we implement a framework for CU identification in the Canada Warbler (Cardellina canadensis), a migratory bird species of conservation concern, and then integrate demographic modelling and genomic offset to guide conservation decisions. We find that patterns of whole genome genetic variation in this highly mobile species are primarily driven by putative adaptive variation. Identification of CUs across the breeding range revealed that Canada Warblers fall into two evolutionarily significant units (ESU), and three putative adaptive units (AUs) in the South, East, and Northwest. Quantification of genomic offset, a metric of genetic changes necessary to maintain current gene-environment relationships, revealed significant spatial variation in climate vulnerability, with the Northwestern AU being identified as the most vulnerable to future climate change. Alternatively, quantification of past population trends within each AU revealed the steepest population declines have occurred within the Eastern AU. Overall, we illustrate that genomics-informed CUs provide a strong foundation for identifying current and future regional threats that can be used to inform management strategies for a highly mobile species in a rapidly changing world.


Assuntos
Conservação dos Recursos Naturais , Passeriformes , Animais , Espécies em Perigo de Extinção , Genômica , Evolução Biológica , Mudança Climática
2.
J Anim Ecol ; 92(4): 936-944, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36785976

RESUMO

Recent technological advances have led to a rapid increase in the collection of capture-recapture data in continuous time. Unlike traditional capture-recapture data, the detection times from these technologies are themselves random variables and analysis of these data, therefore, requires models that properly account for stochasticity in both state transitions and detection times. Despite the ubiquity of continuously collected capture-recapture data, the mathematical concepts needed to fit continuous-time models remain unfamiliar to many ecologists. In this paper, I provide an introduction to continuous-time models, with a focus on multi-state capture-recapture data. After reviewing the basic structure of these models, I describe several variations, including constant parameters, temporal variation in state transition rates and autocorrelation in detections. To aid comprehension, each model is accompanied by code to simulate data and fit the model in Stan. Although the models presented in this guide are only a small subset of the variations that are possible to suit the needs of specific datasets or questions, the concepts and code will hopefully serve as a foundation for future analyses, allowing ecologists to develop new and creative approaches to continuous-time modelling.


Assuntos
Ecologia , Modelos Teóricos , Animais
3.
Proc Natl Acad Sci U S A ; 117(23): 12897-12903, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32457137

RESUMO

Over the past half century, migratory birds in North America have shown divergent population trends relative to resident species, with the former declining rapidly and the latter increasing. The role that climate change has played in these observed trends is not well understood, despite significant warming over this period. We used 43 y of monitoring data to fit dynamic species distribution models and quantify the rate of latitudinal range shifts in 32 species of birds native to eastern North America. Since the early 1970s, species that remain in North America throughout the year, including both resident and migratory species, appear to have responded to climate change through both colonization of suitable area at the northern leading edge of their breeding distributions and adaption in place at the southern trailing edges. Neotropical migrants, in contrast, have shown the opposite pattern: contraction at their southern trailing edges and no measurable shifts in their northern leading edges. As a result, the latitudinal distributions of temperate-wintering species have increased while the latitudinal distributions of neotropical migrants have decreased. These results raise important questions about the mechanisms that determine range boundaries of neotropical migrants and suggest that these species may be particularly vulnerable to future climate change. Our results highlight the potential importance of climate change during the nonbreeding season in constraining the response of migratory species to temperature changes at both the trailing and leading edges of their breeding distributions. Future research on the interactions between breeding and nonbreeding climate change is urgently needed.


Assuntos
Distribuição Animal/fisiologia , Migração Animal/fisiologia , Aves/fisiologia , Mudança Climática , Animais , Monitorização de Parâmetros Ecológicos/estatística & dados numéricos , Geografia , América do Norte , Dinâmica Populacional/estatística & dados numéricos , Estações do Ano
4.
Public Health ; 225: 263-266, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37952342

RESUMO

OBJECTIVES: To outline the management of a community cluster of serogroup B invasive meningococcal disease (IMD) cases, including key factors for decision making and the choice and implementation of control measures. STUDY DESIGN: Descriptive report of cluster management. METHODS: Subtyping of IMD cases identified a number of potentially linked cases in a defined geographical area. An Incident Management Team (IMT) was convened to coordinate the public health response. A case definition was developed in order to identify further cases within the cluster. RESULTS: Four cases of IMD met the case definition and were initially considered as part of this cluster. Three resided in the same small town, which was the focus for public health management. The IMT agreed that it would be proportionate to instigate additional control measures. The population at higher risk of infection were identified, and a supplementary vaccination programme was rolled out in the community. Over five clinics, 45.6% (639/1401) of the target cohort received at least one dose of the vaccine, with 34.7% (486/1401) receiving both doses. Inequalities in uptake were observed by sex, age and deprivation. CONCLUSIONS: Decision making for public health responses to IMD clusters is complex. Informed by epidemiological evidence, numerous partners engaged in collaborative decision making, which was critical for the effective implementation of the community response. Links between the local authority public health team and the community enabled the use of existing structures and relationships to maximise the number of vaccinations delivered. No further cases of IMD linked to this cluster were identified.


Assuntos
Infecções Meningocócicas , Vacinas Meningocócicas , Neisseria meningitidis , Humanos , Incidência , Vacinas Meningocócicas/uso terapêutico , Infecções Meningocócicas/epidemiologia , Infecções Meningocócicas/prevenção & controle , Programas de Imunização
5.
Australas Psychiatry ; 31(5): 619-624, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37473424

RESUMO

OBJECTIVE: Deliberate foreign body ingestion (DFBI) is characterised by recurrent presentations among patients with mental health conditions, intellectual disabilities and in prisoners. We aimed to profile the characteristics and evaluate the care of such patients in this study. METHODS: Adult patients with an endoscopic record of attempted foreign body retrieval between January 2013 and September 2020 were identified at three Australian hospitals. Those with a documented mental health diagnosis were included and their standard medical records reviewed. Presentation history, demographics, comorbidities and endoscopic findings were recorded and described. RESULTS: A total of 166 admissions were accounted for by 35 patients, 2/3 of which had borderline personality disorder (BPD). Repetitive presentations occurred in more than half of the cohort. There was an increased trend of hospital admissions throughout the years. At least half of the cohort had a documented mental health review during their admission. An average of 3.3 (2.9) foreign bodies were ingested per single episode. Endoscopic intervention was performed in 76.5% of incidents. The combined Length of stay for all patients was 680 days. CONCLUSION: Deliberate foreign body ingestion in mental health patients is a common, recurring and challenging problem that is increasing in frequency and requires collaborative research to further guide holistic management.


Assuntos
Corpos Estranhos , Transtornos Mentais , Adulto , Humanos , Austrália/epidemiologia , Transtornos Mentais/epidemiologia , Transtornos Mentais/terapia , Estudos Retrospectivos , Ingestão de Alimentos , Corpos Estranhos/epidemiologia , Corpos Estranhos/terapia
6.
Osteoporos Int ; 33(10): 2165-2175, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35711006

RESUMO

This post hoc analysis and modeling study examined the mechanism of action of odanacatib using a statistical model to explain sCTx response in ODN-treated patients as a function of other bone-turnover biomarkers that, with other observed biomarker changes, showed that odanacatib persistently inhibited osteoclastic bone removal activity without preventing osteoclastogenesis. INTRODUCTION: Odanacatib (ODN) is an oral selective cathepsin K (CatK) inhibitor, previously in development for osteoporosis treatment. A post hoc analysis examined ODN's mechanism of action on bone-turnover biomarkers. METHODS: A subset of patients who completed 60 months' treatment in the Long-Term Odanacatib Fracture Trial (LOFT; NCT00529373) (N = 112 [57 ODN, 55 placebo]) were evaluated. Serum (s) and urine (u) samples were assayed at baseline and months 6-60 for 10 known bone-remodeling biomarkers: sCTx, uαα- and ußßCTx/Cr, uNTx/Cr, sNTx, uDPD/Cr, sICTP, sTRAP5b, sPINP, and sBSAP. Because the CrossLaps® CTx assay identifies the CTx peptide as well as larger molecular weight CTx-containing peptides, including ICTP, a best-fit model was developed to explain the transient sCTx reduction in ODN-treated patients. RESULTS: ODN persistently reduced the bone-resorption markers sNTx, uNTx/Cr, uαα- and ußßCTx/Cr, and uDPD/Cr, and gradually increased the target-engagement marker sICTP and osteoclast number (sTRAP5b), versus placebo from baseline to month 60. sCTx was transiently reduced with ODN within 12 months, returning to baseline by month 48. Modeling suggested that sCTx changes in the ODN group were primarily due to increased accumulation of larger CTx species, including sICTP. The bone-formation markers sPINP and sBSAP showed partial reductions, versus placebo, in the first 6 months but approached baseline by months 48-60. CONCLUSION: Observed changes in bone-turnover biomarkers support the persistent efficacy of ODN in direct inhibition of osteoclastic bone-resorption activity, without inhibition of osteoclastogenesis. Long-term evaluation also underscores the unique mechanism of ODN on osteoclastic collagen processing and subsequently osteoblastic bone formation. TRIAL REGISTRATION: NCT00529373.


Assuntos
Conservadores da Densidade Óssea , Reabsorção Óssea , Osteoporose Pós-Menopausa , Biomarcadores , Compostos de Bifenilo/uso terapêutico , Conservadores da Densidade Óssea/farmacologia , Conservadores da Densidade Óssea/uso terapêutico , Reabsorção Óssea/induzido quimicamente , Reabsorção Óssea/tratamento farmacológico , Reabsorção Óssea/prevenção & controle , Catepsina K , Feminino , Humanos , Osteoporose Pós-Menopausa/induzido quimicamente , Osteoporose Pós-Menopausa/tratamento farmacológico , Pós-Menopausa
7.
Ultrasound Obstet Gynecol ; 60(3): 338-345, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35238424

RESUMO

OBJECTIVE: To determine whether intrapartum transperineal ultrasound measurement of the angle of progression (AoP) during the second stage of labor can predict uncomplicated operative vaginal delivery (OVD) using vacuum or forceps extraction. METHODS: A systematic search in PubMed, EMBASE, Scopus, Web of Science and Google Scholar was performed from inception to February 2021. Studies assessing the predictive accuracy of AoP, measured using intrapartum transperineal ultrasound, for uncomplicated OVD, defined as successful vaginal delivery within three pulls using forceps or no more than two detachments of the vacuum extractor cup, were included. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Summary receiver-operating-characteristics (ROC) curves, pooled sensitivity and specificity, area under the ROC curve (AUC) and summary likelihood ratios (LRs) were calculated. RESULTS: Seven studies reporting on a total of 782 patients undergoing OVD were included in this systematic review and meta-analysis. Second-stage AoP measured during maternal rest had a pooled sensitivity of 80% (95% CI, 59-92%) and specificity of 89% (95% CI, 76-95%), with a LR+ of 7.3 (95% CI, 3.1-15.8) for uncomplicated OVD. AoP measured during active pushing had a sensitivity of 91% (95% CI, 85-94%) and specificity of 83% (95% CI, 69-92%), with a LR+ of 5.4 (95% CI, 2.7-10.6) for uncomplicated OVD. The performance of AoP measured at rest was particularly high in nulliparous women, with a sensitivity of 87% (95% CI, 75-94%) and specificity of 90% (95% CI, 82-94%) for uncomplicated OVD. CONCLUSION: AoP may be a reliable predictor for uncomplicated OVD when measured during the second stage of labor, especially in nulliparous women. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Parto Obstétrico , Trabalho de Parto , Feminino , Humanos , Apresentação no Trabalho de Parto , Gravidez , Estudos Prospectivos , Curva ROC , Ultrassonografia , Ultrassonografia Pré-Natal
8.
Nature ; 530(7591): 461-4, 2016 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-26855424

RESUMO

The non-equilibrium control of emergent phenomena in solids is an important research frontier, encompassing effects such as the optical enhancement of superconductivity. Nonlinear excitation of certain phonons in bilayer copper oxides was recently shown to induce superconducting-like optical properties at temperatures far greater than the superconducting transition temperature, Tc (refs 4-6). This effect was accompanied by the disruption of competing charge-density-wave correlations, which explained some but not all of the experimental results. Here we report a similar phenomenon in a very different compound, K3C60. By exciting metallic K3C60 with mid-infrared optical pulses, we induce a large increase in carrier mobility, accompanied by the opening of a gap in the optical conductivity. These same signatures are observed at equilibrium when cooling metallic K3C60 below Tc (20 kelvin). Although optical techniques alone cannot unequivocally identify non-equilibrium high-temperature superconductivity, we propose this as a possible explanation of our results.

9.
Anaesthesia ; 77(2): 153-163, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34231200

RESUMO

Intra-operative hypotension frequently complicates anaesthesia in older patients and is implicated in peri-operative organ hypoperfusion and injury. The prevalence and corresponding treatment thresholds of hypotension are incompletely described in the UK. This study aimed to identify prevalence of intra-operative hypotension and its treatment thresholds in UK practice. Patients aged ≥ 65 years were studied prospectively from 196 UK hospitals within a 48-hour timeframe. The primary outcome was the incidence of hypotension (mean arterial pressure <65 mmHg; systolic blood pressure reduction >20%; systolic blood pressure <100 mmHg). Secondary outcomes included the treatment blood pressure threshold for vasopressors; incidence of acute kidney injury; myocardial injury; stroke; and in-hospital mortality. Additionally, anaesthetists providing care for included patients were asked to complete a survey assessing their intended treatment thresholds for hypotension. Data were collected from 4750 patients. Hypotension affected 61.0% of patients when defined as mean arterial pressure <65 mmHg, 91.3% of patients had >20% reduction in systolic blood pressure from baseline and 77.5% systolic blood pressure <100 mmHg. The mean (SD) blood pressure triggering vasopressor therapy was mean arterial pressure 64.2 (11.6) mmHg and the mean (SD) stated intended treatment threshold from the survey was mean arterial pressure 60.6 (9.7) mmHg. A composite adverse outcome of myocardial injury, kidney injury, stroke or death affected 345 patients (7.3%). In this representative sample of UK peri-operative practice, the majority of older patients experienced intra-operative hypotension and treatment was delivered below suggested thresholds. This highlights both potential for intra-operative organ injury and substantial opportunity for improving treatment of intra-operative hypotension.


Assuntos
Anestesia/normas , Hipotensão/diagnóstico , Hipotensão/terapia , Complicações Intraoperatórias/diagnóstico , Complicações Intraoperatórias/terapia , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea/fisiologia , Estudos de Coortes , Feminino , Humanos , Hipotensão/epidemiologia , Complicações Intraoperatórias/epidemiologia , Masculino , Estudos Prospectivos , Fatores de Risco , Inquéritos e Questionários , Reino Unido/epidemiologia
10.
BMC Genomics ; 22(1): 749, 2021 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-34657595

RESUMO

BACKGROUND: Bovine milk contains extracellular vesicles (EVs) that play a role in cellular communication, acting in either an autocrine, paracrine, or an exocrine manner. The unique properties of the EVs protect the cargo against degradation. We profiled the ncRNAs (non-coding RNA) present in the EVs from seven dairy products - raw whole milk, heat-treated skim milk, homogenized heat-treated skim milk, pasteurized homogenized skim milk, pasteurized heavy whipping cream, sweet cream buttermilk and cultured buttermilk with four replicates each, obtained at different processing steps from a commercial dairy plant. EVs and their cargo were extracted by using a validated commercial kit that has been shown to be efficient and specific for EVs. Further, to find the annotation of ncRNAs, we probed bovine and other organism repositories(such as miRBase, miRTarBase, Ensemble) to find homolog ncRNA annotation in case the annotations of ncRNA are not available in Bos Taurus database. RESULTS: Specifically, 30 microRNAs (miRNAs), were isolated throughout all the seven milk samples, which later when annotated with their corresponding 1546 putative gene targets have functions associated with immune response and growth and development. This indicates the potential for these ncRNAs to beneficially support mammary health and growth for the cow as well as neonatal gut maturation. The most abundant miRNAs were bta-miR-125a and human homolog miR-718 based on the abundance values of read count obtained from the milk samples.bta-miR-125a is involved in host bacterial and viral immune response, and human homolog miR-718 is involved in the regulation of p53, VEGF, and IGF signaling pathways, respectively. Sixty-two miRNAs were up-regulated and 121 miRNAs were down-regulated throughout all the milk samples when compared to raw whole milk. In addition, our study explored the putative roles of other ncRNAs which included 88 piRNAs (piwi-interacting RNA), 64 antisense RNAs, and 105 lincRNAs (long-intergenic ncRNAs) contained in the bovine exosomes. CONCLUSION: Together, the results indicate that bovine milk contains significant numbers of ncRNAs with putative regulatory targets associated with immune- and developmental-functions important for neonatal bovine health, and that processing significantly affects the ncRNA expression values; but statistical testing of overall abundance(read counts) of all miRNA samples suggests abundance values aren't much affected. This can be attributed to the breakage of exosomal vesicles during the processing stages. It is worth noting, however, that these gene regulatory targets are putative, and further evidence could be generated through experimental validation.


Assuntos
Exossomos , Vesículas Extracelulares , MicroRNAs , Leite/química , Animais , Bovinos , Feminino , Imunidade , MicroRNAs/genética , RNA não Traduzido/genética
11.
Ecol Lett ; 24(6): 1167-1177, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33742759

RESUMO

Individuals that disperse long distances from their natal site must select breeding patches with no prior knowledge of patch suitability. Despite decades of theoretical studies examining which cues dispersing individuals should use to select breeding patches, few empirical studies have tested the predictions of these theories at spatial scales relevant to long-distance dispersal in wild animal populations. Here, we use a novel assignment model based on multiple intrinsic markers to quantify natal dispersal distances of Wood Thrush (Hylocichla mustelina) breeding in forest fragments. We show that long-distance natal dispersal in this species is more frequent than commonly assumed for songbirds and that habitat selection by these individuals is driven by density-dependence and patch quality but not the amount of habitat surrounding breeding patches. These results represent an important contribution to understanding habitat selection by dispersing individuals, especially with regards to long-distance dispersal.


Assuntos
Animais Selvagens , Aves Canoras , Animais , Sinais (Psicologia) , Ecossistema , Emigração e Imigração , Dinâmica Populacional
12.
Phys Rev Lett ; 127(23): 237002, 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34936766

RESUMO

We present a systematic investigation of muon-stopping states in superconductors that reportedly exhibit spontaneous magnetic fields below their transition temperatures due to time-reversal symmetry breaking. These materials include elemental rhenium, several intermetallic systems, and Sr_{2}RuO_{4}. We demonstrate that the presence of the muon leads to only a limited and relatively localized perturbation to the local crystal structure, while any small changes to the electronic structure occur several electron volts below the Fermi energy, leading to only minimal changes in the charge density on ions close to the muon. Our results imply that the muon-induced perturbation alone is unlikely to lead to the observed spontaneous fields in these materials, whose origin is more likely intrinsic to the time-reversal symmetry-broken superconducting state.

13.
Int J Colorectal Dis ; 36(10): 2199-2204, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34244858

RESUMO

PURPOSE: The carrier frequency of MUTYH pathogenic variants in the population may be as high as one in 45. Some studies have found an increased risk of colorectal cancer (CRC) in monoallelic carriers of MUTYH pathogenic variants, but the role of early surveillance colonoscopy is not conclusive. This study aimed to assess the outcomes of colonoscopy surveillance in MUTYH carriers. METHODS: Patients, with a monoallelic pathogenic variant in MUTYH, found at cascade testing, were identified from the St Mark's Hospital Polyposis Registry database. Findings at surveillance colonoscopy were reviewed. RESULTS: Two hundred and forty-nine carriers were identified, of whom 125 had undergone at least one surveillance colonoscopy. Twenty-eight patients (22%) developed at least one adenoma; all adenomas had low-grade dysplasia (LGD). The median age at first colonoscopy was 36 years (range 16-75 years). The median age at first adenoma detection was 43 years (range 22-75 years). The cumulative incidence of adenoma development by age 30, 40, 50, 60 and 70 years was 3.2%, 8.8%, 15.2%, 18.4% and 20.8%, respectively. No CRCs were observed. CONCLUSIONS: Our cohort of monoallelic carriers of MUTYH pathogenic variants is a relatively younger group than adults entering population screening colonoscopy, but a high adenoma rate was not observed. No CRCs were detected, suggesting that current guidance that these individuals should be managed in the same way as the general population is reasonable.


Assuntos
Adenoma , Polipose Adenomatosa do Colo , Neoplasias Colorretais , DNA Glicosilases , Adenoma/epidemiologia , Adenoma/genética , Adolescente , Adulto , Idoso , Neoplasias Colorretais/genética , DNA Glicosilases/genética , Heterozigoto , Humanos , Pessoa de Meia-Idade , Mutação , Adulto Jovem
14.
Mol Cell Neurosci ; 103: 103467, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32004684

RESUMO

During neural development, complex organisms rely on progressive and regressive events whereby axons, synapses, and neurons are overproduced followed by selective elimination of a portion of these components. Tumor necrosis factor α (TNFα) together with its cognate receptor (Tumor necrosis factor receptor 1; TNFR1) have been shown to play both regressive (i.e. forward signaling from the receptor) and progressive (i.e. reverse signaling from the ligand) roles in sympathetic neuron development. In contrast, a paralog of TNFR1, p75 neurotrophic factor receptor (p75NTR) promotes mainly regressive developmental events in sympathetic neurons. Here we examine the interplay between these paralogous receptors in the regulation of axon branch elimination and arborization. We confirm previous reports that these TNFR1 family members are individually capable of promoting ligand-dependent suppression of axon growth and branching. Remarkably, p75NTR and TNFR1 physically interact and p75NTR requires TNFR1 for ligand-dependent axon suppression of axon branching but not vice versa. We also find that p75NTR forward signaling and TNFα reverse signaling are functionally antagonistic. Finally, we find that TNFα reverse signaling is necessary for nerve growth factor (NGF) dependent axon growth. Taken together these findings demonstrate several levels of synergistic and antagonistic interactions using very few signaling pathways and that the balance of these synergizing and opposing signals act to ensure proper axon growth and patterning.


Assuntos
Axônios/metabolismo , Receptores de Fator de Crescimento Neural/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Animais , Células Cultivadas , Camundongos Knockout , Neurogênese/fisiologia , Transdução de Sinais/fisiologia
15.
Phys Rev Lett ; 125(2): 027203, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32701346

RESUMO

The ground state of the simple Heisenberg nearest-neighbor quantum kagome antiferromagnetic model is a magnetically disordered spin liquid, yet various perturbations may lead to fundamentally different states. Here we disclose the origin of magnetic ordering in the structurally perfect kagome material YCu_{3}(OH)_{6}Cl_{3}, which is free of the widespread impurity problem. Ab initio calculations and modeling of its magnetic susceptibility reveal that, similar to the archetypal case of herbertsmithite, the nearest-neighbor exchange is by far the dominant isotropic interaction. Dzyaloshinskii-Moriya (DM) anisotropy deduced from electron spin resonance, susceptibility, and specific-heat data is, however, significantly larger than in herbertsmithite. By enhancing spin correlations within kagome planes, this anisotropy is essential for magnetic ordering. Our study isolates the effect of DM anisotropy from other perturbations and unambiguously confirms the predicted phase diagram.

16.
Br J Nutr ; 123(12): 1406-1414, 2020 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-32131903

RESUMO

Starting university is an important time with respect to dietary changes. This study reports a novel approach to assessing student diet by utilising student-level food transaction data to explore dietary patterns. First-year students living in catered accommodation at the University of Leeds (UK) received pre-credited food cards for use in university catering facilities. Food card transaction data were obtained for semester 1, 2016 and linked with student age and sex. k-Means cluster analysis was applied to the transaction data to identify clusters of food purchasing behaviours. Differences in demographic and behavioural characteristics across clusters were examined using χ2 tests. The semester was divided into three time periods to explore longitudinal changes in purchasing patterns. Seven dietary clusters were identified: 'Vegetarian', 'Omnivores', 'Dieters', 'Dish of the Day', 'Grab-and-Go', 'Carb Lovers' and 'Snackers'. There were statistically significant differences in sex (P < 0·001), with women dominating the Vegetarian and Dieters, age (P = 0·003), with over 20s representing a high proportion of the Omnivores and time of day of transactions (P < 0·001), with Dieters and Snackers purchasing least at breakfast. Many students (n 474, 60·4 %) changed dietary cluster across the semester. This study demonstrates that transactional data present a feasible method for dietary assessment, collecting detailed dietary information over time and at scale, while eliminating participant burden and possible bias from self-selection, observation and attrition. It revealed that student diets are complex and that simplistic measures of diet, focusing on narrow food groups in isolation, are unlikely to adequately capture dietary behaviours.


Assuntos
Inquéritos sobre Dietas/métodos , Dieta/estatística & dados numéricos , Utilização de Instalações e Serviços/estatística & dados numéricos , Serviços de Alimentação/estatística & dados numéricos , Estudantes/estatística & dados numéricos , Adolescente , Comportamento do Consumidor , Comportamento Alimentar , Feminino , Humanos , Estudos Longitudinais , Masculino , Estudos Retrospectivos , Universidades , Adulto Jovem
17.
Colorectal Dis ; 22(10): 1271-1278, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32307808

RESUMO

AIM: The aim was to determine the presentation, management and outcomes of MUTYH-associated polyposis (MAP). METHOD: A prospectively maintained database was used to identify patients with MAP. Demographic data and data on germline mutation, surgical management, histopathology of tumours and endoscopic surveillance were collected. RESULTS: In all, 134 patients with MAP were identified. The majority presented symptomatically (n = 83). Sixty-eight patients developed cancer (seven synchronous, 12 metachronous). The median age at diagnosis of first colorectal cancer was 47 years (range 33-74 years). Cancers occurred in the context of a few adenomas (< 10). The majority of patients (n = 108) had surgery as the first line management. One patient received palliative care. Twenty-five patients had endoscopic surveillance as first line management; no cancers occurred in this group. Patients who had segmental resection and postoperative surveillance still appeared to be at risk of metachronous cancer (5/30, 17%). CONCLUSIONS: MUTYH testing should be considered even in the context of cancers occurring with fewer than 10 adenomas. In cases of primary colorectal cancers, extended surgery should be considered if patients do not have access to high quality endoscopic surveillance postoperatively. For some patients, endoscopic therapy is an appropriate and safe option in expert hands.


Assuntos
Adenoma , Polipose Adenomatosa do Colo , Neoplasias Colorretais , DNA Glicosilases , Adenoma/genética , Adenoma/terapia , Polipose Adenomatosa do Colo/genética , Polipose Adenomatosa do Colo/cirurgia , Adulto , Idoso , Neoplasias Colorretais/genética , Neoplasias Colorretais/terapia , DNA Glicosilases/genética , Predisposição Genética para Doença , Humanos , Pessoa de Meia-Idade , Mutação , Fenótipo
18.
Colorectal Dis ; 22(10): 1436-1439, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32304181

RESUMO

AIM: Restorative proctocolectomy has been widely adopted as the procedure of choice for restoring gastrointestinal continuity following proctocolectomy. It is often associated with improved quality of life and high patient satisfaction; however, the development of a pouch anal fistula can cause significant morbidity. Pouch fistulas are notoriously difficult to treat and there is great heterogeneity in the management reported of these fistulas. A lack of classification, and the assumption that fistulas originating from completely different aetiologies will behave and respond similarly to a particular treatment strategy, precludes meaningful comparison of management outcomes. We aim to introduce consistency in the reporting of pouch fistulas using a novel classification system. METHODS: A consensus process involving clinicians experienced in the management of pouch fistulas from two high volume tertiary centres was performed. RESULTS: We propose that pouch anal fistulas should be classified into four distinct groups according to their aetiology: group 1, anastomotic related; group 2, inflammatory bowel disease related, with sub-classifications Crohn's (type A) and non-Crohn's (type B) in origin; group 3, cryptoglandular related; and group 4, malignancy related. CONCLUSION: Classification of pouch fistulas according to their aetiology will provide consistency in the literature and improve the quality of prospective evidence for the management of pouch fistulas.


Assuntos
Bolsas Cólicas , Proctocolectomia Restauradora , Fístula Retal , Bolsas Cólicas/efeitos adversos , Humanos , Proctocolectomia Restauradora/efeitos adversos , Estudos Prospectivos , Qualidade de Vida , Fístula Retal/etiologia , Fístula Retal/cirurgia
19.
Colorectal Dis ; 22(7): 799-805, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31943692

RESUMO

AIM: Colectomy in patients with adenomatous polyposis (AP) syndromes demands good oncological and surgical outcome. Total colectomy with ileorectal anastomosis (TC-IRA) is one surgical option for these patients. Anastomotic leakage rates of 11% have been reported following TC-IRA. Ileo-distal sigmoid anastomosis (IDSA) is a recent modification of our practice. Our aim was to compare postoperative outcome in patients with AP following near-total colectomy with IDSA (NT-IDSA) and TC-IRA at a single institution. METHOD: A prospectively maintained database was reviewed to identify patients with AP who underwent laparoscopic NT-IDSA and TC-IRA. Patient demographics, early morbidity and mortality and outcome of endoscopic surveillance were evaluated. RESULTS: A total of 191 patients with AP underwent laparoscopic colectomy between 2006 and 2017, of whom 139 (72.8%) underwent TC-IRA and 52 (27.2%) NT-IDSA. The median age at surgery in the TC-IRA and NT-IDSA groups was 20 years (IQR 17-45) and 27 years (IQR 19-50), respectively. Grade II complications were comparable between the two groups. There were no anastomotic leakages in the NT-IDSA group compared with 15 (10.8%) in the TC-IRA group (P = 0.0125) and no reoperation in the NT-IDSA group compared with 17 (12.2%) in the TC-IRA group (P = 0.008). The frequency of polypectomies per flexible sigmoidoscopy was comparable between the two groups. CONCLUSION: This study demonstrates that laparoscopic NT-IDSA for polyposis is associated with a significant improvement in anastomotic leakage rates and surgical outcome. It is too soon to tell whether NT-IDSA alters the need for further intervention, either endoscopic polypectomy or further surgery.


Assuntos
Íleo , Laparoscopia , Anastomose Cirúrgica/efeitos adversos , Colectomia , Humanos , Íleo/cirurgia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Reto/cirurgia , Síndrome
20.
Clin Exp Dermatol ; 45(2): 180-186, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31389055

RESUMO

BACKGROUND: Pain may be associated with actinic keratosis (AK), intraepidermal carcinoma (IEC) and invasive squamous cell carcinoma (SCC), which may all display high-risk features. AIM: To examine variation in pain frequency associated with these three conditions, and assess their invasive SCC surface diameter, invasion depth, grade of differentiation, presence of acantholysis and perineural invasion (PNI). METHODS: Pain was prospectively recorded for consecutive cases of AK, IEC and SCC from three institutions in Australia during the period 2016-2018. RESULTS: Pain with palpation was recorded with 15.8% of AK (n = 30/190), 15.1% of IEC (n = 345/299) and 29.0% invasive SCC (n = 247/853). Pain without palpation was respectively 1.1% (2/190), 4.0% (12/299) and 6.7% (57/853). Invasive SCC with increased surface diameters and deeper invasion recorded increased pain frequency. Pain did not vary significantly by the grade of differentiation in males. In females, well-differentiated SCC recorded more pain (45.4%; n = 473) than poorly differentiated SCC (9.1%; n = 11). Acantholytic SCC recorded more pain 48.7% (n = 29) than nonacantholytic SCC 35.2% (n = 824). Three out of five cases of PNI recorded pain. Pain intensity was not recorded, which was a limitation. CONCLUSION: Pain presence increases from AK to invasive SCC. Pain was more frequent in invasive SCC with increased surface diameter, deeper invasion, acantholysis and PNI. Pain frequency did not vary between the grades of differentiation in males. In females, pain was less frequent in poorly differentiated than in well-differentiated SCC.


Assuntos
Acantólise/complicações , Dor do Câncer , Carcinoma de Células Escamosas/patologia , Ceratose Actínica/complicações , Dor/etiologia , Neoplasias Cutâneas/patologia , Idoso , Dor do Câncer/classificação , Dor do Câncer/patologia , Carcinoma de Células Escamosas/complicações , Feminino , Humanos , Masculino , Gradação de Tumores , Invasividade Neoplásica , Medição da Dor , Estudos Prospectivos , Neoplasias Cutâneas/complicações
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