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1.
Nature ; 615(7954): 813-816, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36991189

RESUMO

The proton is one of the main building blocks of all visible matter in the Universe1. Among its intrinsic properties are its electric charge, mass and spin2. These properties emerge from the complex dynamics of its fundamental constituents-quarks and gluons-described by the theory of quantum chromodynamics3-5. The electric charge and spin of protons, which are shared among the quarks, have been investigated previously using electron scattering2. An example is the highly precise measurement of the electric charge radius of the proton6. By contrast, little is known about the inner mass density of the proton, which is dominated by the energy carried by gluons. Gluons are hard to access using electron scattering because they do not carry an electromagnetic charge. Here we investigated the gravitational density of gluons using a small colour dipole, through the threshold photoproduction of the J/ψ particle. We determined the gluonic gravitational form factors of the proton7,8 from our measurement. We used a variety of models9-11 and determined, in all cases, a mass radius that is notably smaller than the electric charge radius. In some, but not all cases, depending on the model, the determined radius agrees well with first-principle predictions from lattice quantum chromodynamics12. This work paves the way for a deeper understanding of the salient role of gluons in providing gravitational mass to visible matter.

2.
Nature ; 611(7935): 265-270, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36261531

RESUMO

The visible world is founded on the proton, the only composite building block of matter that is stable in nature. Consequently, understanding the formation of matter relies on explaining the dynamics and the properties of the proton's bound state. A fundamental property of the proton involves the response of the system to an external electromagnetic field. It is characterized by the electromagnetic polarizabilities1 that describe how easily the charge and magnetization distributions inside the system are distorted by the electromagnetic field. Moreover, the generalized polarizabilities2 map out the resulting deformation of the densities in a proton subject to an electromagnetic field. They disclose essential information about the underlying system dynamics and provide a key for decoding the proton structure in terms of the theory of the strong interaction that binds its elementary quark and gluon constituents. Of particular interest is a puzzle in the electric generalized polarizability of the proton that remains unresolved for two decades2. Here we report measurements of the proton's electromagnetic generalized polarizabilities at low four-momentum transfer squared. We show evidence of an anomaly to the behaviour of the proton's electric generalized polarizability that contradicts the predictions of nuclear theory and derive its signature in the spatial distribution of the induced polarization in the proton. The reported measurements suggest the presence of a new, not-yet-understood dynamical mechanism in the proton and present notable challenges to the nuclear theory.

3.
EMBO J ; 42(4): e111895, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36688410

RESUMO

C. elegans develops through four larval stages that are rhythmically terminated by molts, that is, the synthesis and shedding of a cuticular exoskeleton. Each larval cycle involves rhythmic accumulation of thousands of transcripts, which we show here relies on rhythmic transcription. To uncover the responsible gene regulatory networks (GRNs), we screened for transcription factors that promote progression through the larval stages and identified GRH-1, BLMP-1, NHR-23, NHR-25, MYRF-1, and BED-3. We further characterize GRH-1, a Grainyhead/LSF transcription factor, whose orthologues in other animals are key epithelial cell-fate regulators. We find that GRH-1 depletion extends molt durations, impairs cuticle integrity and shedding, and causes larval death. GRH-1 is required for, and accumulates prior to, each molt, and preferentially binds to the promoters of genes expressed during this time window. Binding to the promoters of additional genes identified in our screen furthermore suggests that we have identified components of a core molting-clock GRN. Since the mammalian orthologues of GRH-1, BLMP-1 and NHR-23, have been implicated in rhythmic homeostatic skin regeneration in mouse, the mechanisms underlying rhythmic C. elegans molting may apply beyond nematodes.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Camundongos , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Muda/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Mamíferos/genética
4.
Nature ; 578(7795): 409-412, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32076219

RESUMO

Atmospheric methane (CH4) is a potent greenhouse gas, and its mole fraction has more than doubled since the preindustrial era1. Fossil fuel extraction and use are among the largest anthropogenic sources of CH4 emissions, but the precise magnitude of these contributions is a subject of debate2,3. Carbon-14 in CH4 (14CH4) can be used to distinguish between fossil (14C-free) CH4 emissions and contemporaneous biogenic sources; however, poorly constrained direct 14CH4 emissions from nuclear reactors have complicated this approach since the middle of the 20th century4,5. Moreover, the partitioning of total fossil CH4 emissions (presently 172 to 195 teragrams CH4 per year)2,3 between anthropogenic and natural geological sources (such as seeps and mud volcanoes) is under debate; emission inventories suggest that the latter account for about 40 to 60 teragrams CH4 per year6,7. Geological emissions were less than 15.4 teragrams CH4 per year at the end of the Pleistocene, about 11,600 years ago8, but that period is an imperfect analogue for present-day emissions owing to the large terrestrial ice sheet cover, lower sea level and extensive permafrost. Here we use preindustrial-era ice core 14CH4 measurements to show that natural geological CH4 emissions to the atmosphere were about 1.6 teragrams CH4 per year, with a maximum of 5.4 teragrams CH4 per year (95 per cent confidence limit)-an order of magnitude lower than the currently used estimates. This result indicates that anthropogenic fossil CH4 emissions are underestimated by about 38 to 58 teragrams CH4 per year, or about 25 to 40 per cent of recent estimates. Our record highlights the human impact on the atmosphere and climate, provides a firm target for inventories of the global CH4 budget, and will help to inform strategies for targeted emission reductions9,10.


Assuntos
Atmosfera/química , Combustíveis Fósseis/história , Combustíveis Fósseis/provisão & distribuição , Atividades Humanas/história , Metano/análise , Metano/história , Biomassa , Radioisótopos de Carbono , Carvão Mineral/história , Carvão Mineral/provisão & distribuição , Aquecimento Global/prevenção & controle , Aquecimento Global/estatística & dados numéricos , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , Camada de Gelo/química , Metano/química , Gás Natural/história , Gás Natural/provisão & distribuição , Petróleo/história , Petróleo/provisão & distribuição
6.
Hum Mol Genet ; 31(7): 1151-1158, 2022 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-34788822

RESUMO

BACKGROUND: Higher serum homocysteine is associated with cognitive decline in older people. But homocysteine-lowering trials including folic acid (FA) show inconsistent results on cognitive decline. The reduction of FA to dihydrofolate by dihydrofolate reductase (DHFR) is slow in humans. OBJECTIVE: We examined the effects of the DHFR 19-bp deletion/insertion (del/ins) polymorphism on FA-containing treatment on cognitive decline and brain atrophy in older people with mild cognitive impairment (MCI). METHODS: This study used pooled data from two randomized B-vitamin trials on 545 MCI subjects who received either FA-containing B vitamins or placebo for 24 months. Subjects were typed for the DHFR genotype. Primary outcome was the Clinical Dementia Rating scale-global score (CDR-global). Secondary outcomes were CDR-sum of boxes score (CDR-SOB), memory and executive Z-scores and whole brain atrophy rate by serial MRI. RESULTS: The proportions of subjects with del/del, del/ins and ins/ins genotype were 29.5, 44.3 and 26.1%, respectively. DHFR genotypes modified the effects of B vitamins on CDR-global, CDR-SOB and executive function Z-score (Pinteraction = 0.017, 0.014 and 0.052, respectively), with significant benefits being observed only in those with ins/ins genotype (Beta = -1.367, -0.614 and 0.315, P = 0.004, 0.014 and 0.012, respectively). The interaction was not significant for memory Z-score and whole brain atrophy rate. Notably, the supplements only slowed brain atrophy in members of the 'ins/ins' group who were not using aspirin. CONCLUSIONS: Our data indicate that the beneficial effects of B vitamins including FA on cognitive function are only apparent in those with ins/ins genotype, i.e. relatively better preserved DHFR activity.


Assuntos
Transtornos Cognitivos , Disfunção Cognitiva , Complexo Vitamínico B , Idoso , Cognição , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/genética , Humanos , Tetra-Hidrofolato Desidrogenase/genética , Tetra-Hidrofolato Desidrogenase/farmacologia , Complexo Vitamínico B/uso terapêutico
7.
J Peripher Nerv Syst ; 29(1): 88-96, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37989721

RESUMO

BACKGROUND AND AIMS: Why only half of the idiopathic peripheral neuropathy (IPN) patients develop neuropathic pain remains unknown. By conducting a proteomics analysis on IPN patients, we aimed to discover proteins and new pathways that are associated with neuropathic pain. METHODS: We conducted unbiased mass-spectrometry proteomics analysis on blood plasma from 31 IPN patients with severe neuropathic pain and 29 IPN patients with no pain, to investigate protein biomarkers and protein-protein interactions associated with neuropathic pain. Univariate modeling was done with linear mixed modeling (LMM) and corrected for multiple testing. Multivariate modeling was performed using elastic net analysis and validated with internal cross-validation and bootstrapping. RESULTS: In the univariate analysis, 73 proteins showed a p-value <.05 and 12 proteins showed a p-value <.01. None were significant after Benjamini-Hochberg adjustment for multiple testing. Elastic net analysis created a model containing 12 proteins with reasonable discriminatory power to differentiate between painful and painless IPN (false-negative rate 0.10, false-positive rate 0.18, and an area under the curve 0.75). Eight of these 12 proteins were clustered into one interaction network, significantly enriched for the complement and coagulation pathway (Benjamini-Hochberg adjusted p-value = .0057), with complement component 3 (C3) as the central node. Bootstrap validation identified insulin-like growth factor-binding protein 2 (IGFBP2), complement factor H-related protein 4 (CFHR4), and ferritin light chain (FTL), as the most discriminatory proteins of the original 12 identified. INTERPRETATION: This proteomics analysis suggests a role for the complement system in neuropathic pain in IPN.


Assuntos
Neuralgia , Proteômica , Humanos , Neuralgia/etiologia , Proteínas , Plasma
8.
Health Educ Res ; 39(2): 182-196, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38300230

RESUMO

The objectives of the study were to (i) document refugee, immigrant and migrant (RIM) communities' knowledge, attitudes and beliefs (KABs) related to the Coronavirus disease (COVID-19) vaccine and (ii) identify best practices for developing and disseminating culturally and linguistically responsive health messaging addressing those KABs. Thirteen online focus groups (OFGs) in 10 languages were conducted. Each OFG was conducted in the participants' native language. OFGs were recorded, transcribed, translated and uploaded to qualitative software for coding. A thematic analysis was conducted. Results suggest that while there was some variation between different language groups (e.g. whether religious leaders were seen as trusted sources of information about COVID), there were also important commonalities. Most language groups (i) alluded to hearing about or having gaps in knowledge about COVID-19/the COVID-19 vaccine, (ii) reported hearing negative or conflicting stories about the vaccine and (iii) shared concerns about the negative side effects of the vaccine. There continues to be a need for health messaging in RIM communities that is culturally and linguistically concordant and follows health literacy guidelines. Message content about the COVID-19 vaccine should focus on vaccine importance, effectiveness and safety, should be multimodal and should be primarily delivered by healthcare professionals and community members who have already been vaccinated.


Assuntos
COVID-19 , Emigrantes e Imigrantes , Refugiados , Migrantes , Humanos , Vacinas contra COVID-19 , Cidades , Conhecimentos, Atitudes e Prática em Saúde , COVID-19/prevenção & controle
9.
J Obstet Gynaecol Can ; 46(8): 102578, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38852809

RESUMO

OBJECTIVES: The Healthy Recovery after Childbirth Clinic (HRCC) in Nova Scotia provides postpartum care to patients who experience obstetric anal sphincter injuries (OASIS). The purpose of this study was to describe characteristics associated with HRCC attendance, characteristics associated with a trial of labour in a subsequent delivery, and OASIS recurrence by HRCC attendance status. METHODS: A retrospective cohort study using the Atlee Perinatal Database and clinical record review included primiparous individuals who sustained an OASIS at IWK Health in Halifax between 2013 and 2020. The χ2 and Fisher exact tests were performed to compare groups. RESULTS: Of the 1041 individuals included, 67% attended HRCC. Attendance increased from 58% in 2013-2015 to 77% in 2019-2020. Younger age (<25 years) and smoking were associated with lower HRCC attendance (P = 0.07 and <0.01, respectively). Other characteristics, including area-level income and driving distance to HRCC, were not associated with attendance (P > 0.05). Of the 439 individuals who had a subsequent delivery, 92% had a trial of labour. Individuals with fourth-degree injury were less likely to attempt a trial of labour than those with third-degree injury (73% vs. 94%, P < 0.01). Of those who delivered vaginally, OASIS recurrence was similar in those who did and did not attend the HRCC (7.5% vs. 6.5%, P = 0.84). CONCLUSIONS: HRCC attendance was high, but the disparity by age and smoking status suggests some barriers to access that should be explored. Although we found no difference in OASIS recurrence by HRCC attendance, more research with larger samples with adjustment for confounders is needed.

10.
Phys Rev Lett ; 130(20): 202501, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37267578

RESUMO

We demonstrate a new technique for obtaining fission data for nuclei away from ß stability. These types of data are pertinent to the astrophysical r process, crucial to a complete understanding of the origin of the heavy elements, and for developing a predictive model of fission. These data are also important considerations for terrestrial applications related to power generation and safeguarding. Experimentally, such data are scarce due to the difficulties in producing the actinide targets of interest. The solenoidal-spectrometer technique, commonly used to study nucleon-transfer reactions in inverse kinematics, has been applied to the case of transfer-induced fission as a means to deduce the fission-barrier height, among other variables. The fission-barrier height of ^{239}U has been determined via the ^{238}U(d,pf) reaction in inverse kinematics, the results of which are consistent with existing neutron-induced fission data indicating the validity of the technique.

11.
Brain Behav Immun ; 109: 321-330, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36796705

RESUMO

BACKGROUND: Whether lung function prospectively affects cognitive brain health independent of their overlapping factors remains largely unknown. This study aimed to investigate the longitudinal association between decreased lung function and cognitive brain health and to explore underlying biological and brain structural mechanisms. METHODS: This population-based cohort included 43,1834 non-demented participants with spirometry from the UK Biobank. Cox proportional hazard models were fitted to estimate the risk of incident dementia for individuals with low lung function. Mediation models were regressed to explore the underlying mechanisms driven by inflammatory markers, oxygen-carrying indices, metabolites, and brain structures. FINDINGS: During a follow-up of 3,736,181 person-years (mean follow-up 8.65 years), 5,622 participants (1.30 %) developed all-cause dementia, which consisted of 2,511 Alzheimer's dementia (AD) and 1,308 Vascular Dementia (VD) cases. Per unit decrease in lung function measure was each associated with increased risk for all-cause dementia (forced expiratory volume in 1 s [liter]: hazard ratio [HR, 95 %CI], 1.24 [1.14-1.34], P = 1.10 × 10-07; forced vital capacity [liter]: 1.16 [1.08-1.24], P = 2.04 × 10-05; peak expiratory flow [liter/min]: 1.0013 [1.0010-1.0017], P = 2.73 × 10-13). Low lung function generated similar hazard estimates for AD and VD risks. As underlying biological mechanisms, systematic inflammatory markers, oxygen-carrying indices, and specific metabolites mediated the effects of lung function on dementia risks. Besides, brain grey and white matter patterns mostly affected in dementia were substantially changed with lung function. INTERPRETATION: Life-course risk for incident dementia was modulated by individual lung function. Maintaining optimal lung function is useful for healthy aging and dementia prevention.


Assuntos
Doença de Alzheimer , Humanos , Estudos Prospectivos , Encéfalo , Pulmão , Oxigênio , Fatores de Risco
12.
Mol Psychiatry ; 27(8): 3385-3395, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35538193

RESUMO

Cohort studies report inconsistent associations between body mass index (BMI) and all-cause incident dementia. Furthermore, evidence on fat distribution and body composition measures are scarce and few studies estimated the association between early life adiposity and dementia risk. Here, we included 322,336 participants from UK biobank to investigate the longitudinal association between life course adiposity and risk of all-cause incident dementia and to explore the underlying mechanisms driven by metabolites, inflammatory cells and brain structures. Among the 322,336 individuals (mean (SD) age, 62.24 (5.41) years; 53.9% women) in the study, during a median 8.74 years of follow-up, 5083 all-cause incident dementia events occurred. The risk of dementia was 22% higher with plumper childhood body size (p < 0.001). A strong U-shaped association was observed between adult BMI and dementia. More fat and less fat-free mass distribution on arms were associated with a higher risk of dementia. Interestingly, similar U-shaped associations were found between BMI and four metabolites (i.e., 3-hydroxybutrate, acetone, citrate and polyunsaturated fatty acids), four inflammatory cells (i.e., neutrophil, lymphocyte, monocyte and leukocyte) and abnormalities in brain structure that were also related to dementia. The findings that adiposity is associated with metabolites, inflammatory cells and abnormalities in brain structure that were related to dementia risk might provide clues to underlying biological mechanisms. Interventions to prevent dementia should begin early in life and include not only BMI control but fat distribution and body composition.


Assuntos
Adiposidade , Demência , Adulto , Humanos , Feminino , Criança , Pessoa de Meia-Idade , Masculino , Estudos Prospectivos , Acontecimentos que Mudam a Vida , Fatores de Risco , Obesidade , Índice de Massa Corporal , Estudos de Coortes , Demência/epidemiologia
13.
Eur J Nutr ; 62(3): 1551-1559, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36469110

RESUMO

Vitamin B12 is an essential nutrient that is not made by plants; consequently, unfortified plant-based foods are not a reliable supply. Recent estimates suggest high rates of vitamin B12 deficiency among the vegetarian and vegan populations, particularly in pregnant women or women of child-bearing age who, for ethical and health reasons, are shifting towards higher consumption of plant-based foods in ever-increasing numbers. Vitamin B12 plays crucial metabolic roles across the life-course and in particular during pregnancy and in early development (first 1000 days of life). Evidence now implicates vitamin B12 deficiency with increased risk to a range of neuro, vascular, immune, and inflammatory disorders. However, the current UK recommended nutrient intake for vitamin B12 does not adequately consider the vitamin B12 deficit for those choosing a plant-based diet, including vegetarianism and in particular veganism, representing a hidden hunger. We provide a cautionary note on the importance of preventing vitamin B12 deficits for those individuals choosing a plant-based diet and the health professionals advising them.


Assuntos
Dieta , Vitamina B 12 , Humanos , Feminino , Gravidez , Dieta Vegetariana/efeitos adversos , Dieta Vegana , Vitaminas
14.
Spinal Cord ; 61(8): 436-440, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37120699

RESUMO

STUDY DESIGN: Cohort study. Retrospective analysis of T2-weighted magnetic resonance images (MRIs) and clinical documentation. OBJECTIVES: To evaluate the relationship between the presence/absence and widths of midsagittal tissue bridges and walking ability among veterans with cervical, predominantly chronic SCI. SETTING: University research and hospital setting. METHODS: T2-weighted midsagittal MRIs of 22 United States veterans with cervical spinal cord injuries were examined. The presence/absence of midsagittal tissue bridges were determined, and the widths of present ventral and dorsal tissue bridges were measured. Midsagittal tissue bridge characteristics were related to each participant's ability to walk based off examination of clinical documentation. RESULTS: Fourteen of the analyzed participant images revealed the presence of midsagittal tissue bridges. Ten of those individuals (71%) possessed overground walking ability. The 8 individuals with no apparent tissue bridges were all unable to walk. There was a significant correlation between walking and widths of ventral midsagittal tissue bridges (r = 0.69, 95%CI: 0.52, 0.92, p < 0.001), as well as dorsal midsagittal tissue bridges (r = 0.44, 95%CI: 0.15, 0.73, p = 0.039). CONCLUSION: The evaluation of midsagittal tissue bridges may be useful in various rehabilitation settings to help inform patients' plan of care, allocation of neuromodulatory resources, and appropriate stratification into research cohorts.


Assuntos
Traumatismos da Medula Espinal , Humanos , Traumatismos da Medula Espinal/diagnóstico por imagem , Estudos Retrospectivos , Estudos de Coortes , Caminhada , Imageamento por Ressonância Magnética/métodos , Medula Espinal
15.
J Dairy Sci ; 106(5): 3176-3191, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36894426

RESUMO

A multicenter observational study to evaluate genome-wide association was conducted in early-lactation Holstein cows (n = 293) from 36 herds in Canada, the USA, and Australia. Phenotypic observations included rumen metabolome, acidosis risk, ruminal bacterial taxa, and milk composition and yield measures. Diets ranged from pasture supplemented with concentrates to total mixed rations (nonfiber carbohydrates = 17 to 47, and neutral detergent fiber = 27 to 58% of dry matter). Rumen samples were collected <3 h after feeding and analyzed for pH, ammonia, d- and l-lactate, volatile fatty acid (VFA) concentrations, and abundance of bacterial phyla and families. Eigenvectors were produced using cluster and discriminant analyses from a combination of pH and ammonia, d-lactate, and VFA concentrations, and were used to estimate the probability of the risk of ruminal acidosis based on proximity to the centroid of 3 clusters, termed high (24.0% of cows), medium (24.2%), and low risk (51.8%) for acidosis. DNA of sufficient quality was successfully extracted from whole blood (218 cows) or hair (65 cows) collected simultaneously with the rumen samples and sequenced using the Geneseek Genomic Profiler Bovine 150K Illumina SNPchip. Genome-wide association used an additive model and linear regression with principal component analysis (PCA) population stratification and a Bonferroni correction for multiple comparisons. Population structure was visualized using PCA plots. Single genomic markers were associated with milk protein percent and the center logged ratio abundance of the phyla Chloroflexi, SR1, and Spirochaetes, and tended to be associated with milk fat yield, rumen acetate, butyrate, and isovalerate concentrations and with the probability of being in the low-risk acidosis group. More than one genomic marker was associated or tended to be associated with rumen isobutyrate and caproate concentrations, and the center log ratio of the phyla Bacteroidetes and Firmicutes and center log ratio of the families Prevotellaceae, BS11, S24-7, Acidaminococcaceae, Carnobacteriaceae, Lactobacillaceae, Leuconostocaceae, and Streptococcaceae. The provisional NTN4 gene, involved in several functions, had pleiotropy with 10 bacterial families, the phyla Bacteroidetes and Firmicutes, and butyrate. The ATP2CA1 gene, involved in the ATPase secretory pathway for Ca2+ transport, overlapped for the families Prevotellaceae, S24-7, and Streptococcaceae, the phylum Bacteroidetes, and isobutyrate. No genomic markers were associated with milk yield, fat percentage, protein yield, total solids, energy-corrected milk, somatic cell count, rumen pH, ammonia, propionate, valerate, total VFA, and d-, l-, or total lactate concentrations, or probability of being in the high- or medium-risk acidosis groups. Genome-wide associations with the rumen metabolome, microbial taxa, and milk composition were present across a wide geographical and management range of herds, suggesting the existence of markers for the rumen environment but not for acidosis susceptibility. The variation in pathogenesis of ruminal acidosis in the small population of cattle in the high risk for acidosis group and the dynamic nature of the rumen as cows cycle through a bout of acidosis may have precluded the identification of markers for acidosis susceptibility. Despite a limited sample size, this study provides evidence of interactions between the mammalian genome, the rumen metabolome, ruminal bacteria, and milk protein percentage.


Assuntos
Acidose , Doenças dos Bovinos , Feminino , Animais , Bovinos , Rúmen/metabolismo , Amônia/metabolismo , Estudo de Associação Genômica Ampla/veterinária , Isobutiratos , Lactação , Ácidos Graxos Voláteis/metabolismo , Proteínas do Leite/análise , Butiratos/metabolismo , Dieta/veterinária , Bactérias/metabolismo , Lactatos/análise , Acidose/veterinária , Concentração de Íons de Hidrogênio , Fermentação , Mamíferos/metabolismo , Doenças dos Bovinos/metabolismo
16.
J Dairy Sci ; 106(5): 3155-3175, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36894423

RESUMO

A multicenter observational study was conducted on early lactation Holstein cows (n = 261) from 32 herds from 3 regions (Australia, AU; California, CA; and Canada, CAN) to characterize their risk of acidosis into 3 groups (high, medium, or low) using a discriminant analysis model previously developed. Diets ranged from pasture supplemented with concentrates to total mixed ration (nonfiber carbohydrates = 17 to 47 and neutral detergent fiber = 27 to 58% of dry matter). Rumen fluid samples were collected <3 h after feeding and analyzed for pH, and ammonia, d- and l-lactate, and volatile fatty acid (VFA) concentrations. Eigenvectors were produced using cluster and discriminant analysis from a combination of rumen pH, and ammonia, d-lactate, and individual VFA concentrations and were used to calculate the probability of the risk of ruminal acidosis based on proximity to the centroid of 3 clusters. Bacterial 16S ribosomal DNA sequence data were analyzed to characterize bacteria. Individual cow milk volume, fat, protein, and somatic cell count values were obtained from the closest herd test to the rumen sampling date (median = 1 d before rumen sampling). Mixed model analyses were performed on the markers of rumen fermentation, production characteristics, and the probability of acidosis. A total of 26.1% of the cows were classified as high risk for acidosis, 26.8% as medium risk, and 47.1% as low risk. Acidosis risk differed among regions with AU (37.2%) and CA (39.2%) having similar prevalence of high-risk cows and CAN only 5.2%. The high-risk group had rumen phyla, fermentation, and production characteristics consistent with a model of acidosis that reflected a rapid rate of carbohydrate fermentation. Namely, acetate to propionate ratio (1.98 ± 0.11), concentrations of valerate (2.93 ± 0.14 mM), milk fat to protein ratio (1.11 ± 0.047), and a positive association with abundance of phylum Firmicutes. The medium-risk group contains cows that may be inappetant or that had not eaten recently or were in recovery from acidosis. The low-risk group may represent cattle that are well fed with a stable rumen and a slower rumen fermentation of carbohydrates. The high risk for acidosis group had lower diversity of bacteria than the other groups, whereas CAN had a greater diversity than AU and CA. Rumen fermentation profile, abundance of ruminal bacterial phyla, and production characteristics of early lactation dairy cattle from 3 regions were successfully categorized in 3 different acidosis risk states, with characteristics differing between acidosis risk groups. The prevalence of acidosis risk also differed between regions.


Assuntos
Acidose , Doenças dos Bovinos , Feminino , Animais , Bovinos , Amônia/metabolismo , Rúmen/metabolismo , Leite/química , Lactação , Ácidos Graxos Voláteis/metabolismo , Dieta/veterinária , Ácido Láctico/metabolismo , Carboidratos/análise , Acidose/veterinária , Acidose/metabolismo , Fermentação , Concentração de Íons de Hidrogênio , Ração Animal/análise , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/metabolismo
17.
Int J Biometeorol ; 67(6): 957-973, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37060454

RESUMO

Healthy adult horses can balance accumulation and dissipation of body heat to maintain their body temperature between 37.5 and 38.5 °C, when they are in their thermoneutral zone (5 to 25 °C). However, under some circumstances, such as following strenuous exercise under hot, or hot and humid conditions, the accumulation of body heat exceeds dissipation and horses can suffer from heat stress. Prolonged or severe heat stress can lead to anhidrosis, heat stroke, or brain damage in the horse. To ameliorate the negative effects of high heat load in the body, early detection of heat stress and immediate human intervention is required to reduce the horse's elevated body temperature in a timely manner. Body temperature measurement and deviations from the normal range are used to detect heat stress. Rectal temperature is the most commonly used method to monitor body temperature in horses, but other body temperature monitoring technologies, percutaneous thermal sensing microchips or infrared thermometry, are currently being studied for routine monitoring of the body temperature of horses as a more practical alternative. When heat stress is detected, horses can be cooled down by cool water application, air movement over the horse (e.g., fans), or a combination of these. The early detection of heat stress and the use of the most effective cooling methods is important to improve the welfare of heat stressed horses.


Assuntos
Temperatura Alta , Respiração , Humanos , Cavalos , Animais , Umidade , Temperatura Corporal , Febre , Regulação da Temperatura Corporal
18.
Occup Med (Lond) ; 73(3): 142-147, 2023 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-36864556

RESUMO

BACKGROUND: By the nature of their work, first responders are at risk for post-traumatic stress disorder (PTSD). Efficient screening instruments are useful to identify at-risk first responders and connect them to services. AIMS: The current study aimed to (i) evaluate the diagnostic properties of the Primary Care PTSD for DSM-5 (PC-PTSD-5) scale among firefighters, (ii) explore the use of an adapted PC-PTSD-5 on a five-point Likert-type scale and (iii) examine sensitivity and specificity of the adapted instrument in this population. METHODS: Pooled data were analysed among firefighters (N = 92) from a treatment-seeking sample (n = 36) and a population health screening sample (n = 56). Participants completed an adapted version of the PC-PTSD-5 and the Post-Traumatic Stress Disorder Checklist for DSM-5 (PCL-5). Receiver operating characteristic curve analyses were performed, referencing PCL-5 cut-off/probable diagnostic threshold scores. RESULTS: The PC-PTSD-5 demonstrated excellent operating characteristics overall. A threshold of 3 was optimal for discriminating probable PTSD using a proxy for the original PC-PTSD-5 (range: 0-5), whereas a score of 9 was identified for the PC-PTSD-5 permutation that allowed for more response variability (range: 0-20). CONCLUSIONS: Our preliminary data suggest the PC-PTSD-5 may be a useful tool for brief firefighter screening, with suggested cut-offs that require further replication and expanded investigation.


Assuntos
Bombeiros , Transtornos de Estresse Pós-Traumáticos , Humanos , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Sensibilidade e Especificidade , Curva ROC , Atenção Primária à Saúde
19.
J Struct Biol ; 214(3): 107882, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35850322

RESUMO

This study examines how microscale differences in skeletal ultrastructure affect the crystallographic and nanomechanical properties of two related bryozoan species: (i) Hornera currieae, which is found at relatively quiescent depths of c. 1000 m, and (ii) Hornera robusta, which lives at depths of 50-400 m where it is exposed to currents and storm waves. Microstructural and Electron Backscatter Diffraction (EBSD) observations show that in both species the secondary walls are composed of low-Mg calcite crystallites that grow with their c-axes perpendicular to the wall. Branches in H. currieae develop a strong preferred orientation of the calcite c-axes, while in H. robusta the c-axes are more scattered. Microstructural observations suggest that the degree of scattering is controlled by the underlying morphology of the skeletons: in H. currieae the laminated branch walls are smooth and relatively uninterrupted, whereas the wall architecture of H. robusta is modified by numerous deflections, forming pustules and ridges associated with microscopic tubules. Modelling of the Young's modulus and measurements of nanoindentation hardness indicate that the observed scattering of the crystallite c-axes affects the elastic modulus and nanohardness of the branches, and therefore controls the mechanical properties of the skeletal walls. At relatively high pressure in deep waters, the anisotropic skeletal architecture of H. currieae is aimed at concentrating elasticity normal to the skeleton wall. In comparison, in the relatively shallow and active hydrographic regime of the continental shelf, the elastically isotropic skeleton of H. robusta is designed to increase protection from external predators and stronger omni-directional currents.


Assuntos
Carbonato de Cálcio , Anisotropia , Carbonato de Cálcio/química , Cristalografia , Módulo de Elasticidade , Dureza
20.
Circulation ; 143(24): 2395-2405, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34125564

RESUMO

In the United States, race-based disparities in cardiovascular disease care have proven to be pervasive, deadly, and expensive. African American/Black, Hispanic/Latinx, and Native/Indigenous American individuals are at an increased risk of cardiovascular disease and are less likely to receive high-quality, evidence-based medical care as compared with their White American counterparts. Although the United States population is diverse, the cardiovascular workforce that provides its much-needed care lacks diversity. The available data show that care provided by physicians from racially diverse backgrounds is associated with better quality, both for minoritized patients and for majority patients. Not only is cardiovascular workforce diversity associated with improvements in health care quality, but racial diversity among academic teams and research scientists is linked with research quality. We outline documented barriers to achieving workforce diversity and suggest evidence-based strategies to overcome these barriers. Key strategies to enhance racial diversity in cardiology include improving recruitment and retention of racially diverse members of the cardiology workforce and focusing on cardiovascular health equity for patients. This review draws attention to academic institutions, but the implications should be considered relevant for nonacademic and community settings as well.


Assuntos
Cardiologistas/estatística & dados numéricos , Feminino , Equidade em Saúde , Humanos , Masculino , Grupos Raciais , Estados Unidos , Recursos Humanos
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