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1.
Psychol Psychother ; 97(2): 354-371, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38353112

RESUMO

OBJECTIVES: We investigated the effect of the therapeutic alliance on both change in social recovery outcomes and usage of a moderated online social therapy platform for first-episode psychosis (FEP), Horyzons. DESIGN: Secondary analysis of a single group pilot trial. METHODS: Clients completed an alliance measure adapted for guided digital interventions at mid-treatment. A series of multi-level models evaluated change in outcomes by mid- and post-treatment assessments (relative to baseline) as a function of the overall alliance. Quasi-Poisson models evaluated the effect of the overall alliance on aggregated counts of platform usage. Exploratory analyses repeated these models in terms of the bond (human-human) or the task/goal (human-program) alliance. RESULTS: Stronger overall alliance at mid-treatment predicted lower loneliness at mid-treatment and lower social anxiety at mid- and post-treatment. It was also associated with higher completion of therapy activities and authoring of comments and reactions. A strong bond with an online therapist was associated with lower loneliness and higher perceived social support at mid-treatment, lower social anxiety at post-treatment as well as a higher number of reactions made on the social network. Stronger alliance with the platform's tasks and goals facilitated lower social anxiety at both follow-up assessments and was further associated with higher completion of therapy activities and reactions in the social network. CONCLUSIONS: The alliance may impact aspects of social recovery and usage in digital interventions for FEP. Specific aspects of the alliance (human-human and human-program relationships) should be considered in future research.


Assuntos
Transtornos Psicóticos , Aliança Terapêutica , Humanos , Feminino , Transtornos Psicóticos/terapia , Transtornos Psicóticos/psicologia , Masculino , Adulto , Adulto Jovem , Projetos Piloto , Solidão/psicologia , Apoio Social , Intervenção Baseada em Internet , Resultado do Tratamento
2.
Occup Med (Lond) ; 73(9): 554-556, 2023 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-38079479

RESUMO

BACKGROUND: Staff injuries adversely affect the health of staff members as well the ability of health care teams to effectively care for patients. Identifying patients who pose an increased risk of injury may allow for the planning of risk mitigation strategies, but few studies have examined patient factors associated with staff injury risk. AIMS: Examine the relationship between staff injury and patient mobility, which has been linked to other key hospital outcomes. METHODS: Linking occupational health and electronic medical record data, we examined documented patient mobility levels, based on the Activity Measure for Post-Acute Care (AM-PAC) and the Johns Hopkins Highest Level of Mobility (JH-HLM) Scale, on the day prior to injury. In addition, we created a matched cohort of control patients not associated with staff injury to examine the influence of patient mobility on the odds of staff injury. RESULTS: We identified 199 staff injuries associated with 181 patients with 1063 matched controls. Patients had median scores of 11 and 3 on the AM-PAC and JH-HLM, respectively, indicating moderate-severe mobility impairments. In addition, scores in the lowest AM-PAC tertile (6-15) and lowest JH-HLM tertile (1-4) were associated with a 4.46-fold and 2.90-fold increase in the odds of nurse injury, respectively. CONCLUSIONS: These results indicate that moderate-severe mobility impairments are associated with increased risk of nurse injury. Hospitals and clinical care teams should consider documenting mobility routinely and utilizing these values to identify patients who pose an increased risk of nurse injury.


Assuntos
Hospitais , Limitação da Mobilidade , Humanos
3.
Front Physiol ; 14: 1287392, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38028783

RESUMO

Autonomic adjustments of the cardiovascular system are critical for initiating and sustaining exercise by facilitating the redistribution of blood flow and oxygen delivery to meet the metabolic demands of the active skeletal muscle. Afferent feedback from active skeletal muscles evokes reflex increases in sympathetic nerve activity and blood pressure (BP) (i.e., exercise pressor reflex) and contributes importantly to these primary neurovascular adjustments to exercise. When altered, this reflex contributes significantly to the exaggerated sympathetic and BP response to exercise observed in many cardiovascular-related diseases, highlighting the importance of examining the reflex and its underlying mechanism(s). A leading risk factor for the pathogenesis of cardiovascular disease in both males and females is aging. Although regular exercise is an effective strategy for mitigating the health burden of aging, older adults face a greater risk of experiencing an exaggerated cardiovascular response to exercise. However, the role of aging in mediating the exercise pressor reflex remains highly controversial, as conflicting findings have been reported. This review aims to provide a brief overview of the current understanding of the influence of aging on cardiovascular responses to exercise, focusing on the role of the exercise pressor reflex and proposing future directions for research. We reason that this review will serve as a resource for health professionals and researchers to stimulate a renewed interest in this critical area.

4.
Nat Commun ; 14(1): 7343, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37957145

RESUMO

The key challenge for high-power delivery through optical fibers is overcoming nonlinear optical effects. To keep a smooth output beam, most techniques for mitigating optical nonlinearities are restricted to single-mode fibers. Moving out of the single-mode paradigm, we show experimentally that wavefront-shaping of coherent input light to a highly multimode fiber can increase the power threshold for stimulated Brillouin scattering (SBS) by an order of magnitude, whilst simultaneously controlling the output beam profile. The SBS suppression results from an effective broadening of the Brillouin spectrum under multimode excitation, without broadening of transmitted light. Strongest suppression is achieved with selective mode excitation that gives the broadest Brillouin spectrum. Our method is efficient, robust, and applicable to continuous waves and pulses. This work points toward a promising route for mitigating detrimental nonlinear effects in optical fibers, enabling further power scaling of high-power fiber systems for applications to directed energy, remote sensing, and gravitational-wave detection.

5.
Phys Rev Lett ; 130(25): 250404, 2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37418706

RESUMO

Above-barrier quantum scattering with truncated real potentials V(x)=-|x|^{p} provides an experimentally accessible platform that exhibits spontaneous parity-time symmetry breaking as p is varied. The unbroken phase has reflectionless states that correspond to bound states in the continuum of the nontruncated potentials at arbitrarily high discrete real energies. In the fully broken phase there are no bound states. There is a mixed phase in which exceptional points occur at specific energies and values of p. These effects should be observable in cold-atom scattering experiments.

6.
Proc Natl Acad Sci U S A ; 120(22): e2217735120, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37216557

RESUMO

High-power fiber laser amplifiers have enabled an increasing range of applications in industry, science, and defense. The power scaling for fiber amplifiers is currently limited by transverse mode instability. Most techniques for suppressing the instability are based on single- or few-mode fibers in order to output a clean collimated beam. Here, we study theoretically using a highly multimode fiber amplifier with many-mode excitation for efficient suppression of thermo-optical nonlinearity and instability. We find that the mismatch of characteristic length scales between temperature and optical intensity variations across the fiber generically leads to weaker thermo-optical coupling between fiber modes. Consequently, the transverse mode instability (TMI) threshold power increases linearly with the number of equally excited modes. When the frequency bandwidth of a coherent seed laser is narrower than the spectral correlation width of the multimode fiber, the amplified light maintains high spatial coherence and can be transformed to any target pattern or focused to a diffraction-limited spot by a spatial mask at either the input or output end of the amplifier. Our method simultaneously achieves high average power, narrow spectral width, and good beam quality, which are required for fiber amplifiers in various applications.

7.
BMC Infect Dis ; 23(1): 63, 2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36732697

RESUMO

BACKGROUND: There are limited data on the treatment of blood stream infections (BSIs) in patients receiving extracorporeal membrane oxygenation (ECMO). Current guidance recommends documenting clearance only in fungal and Gram-positive BSIs. This study investigates the incidence and clinical significance of blood stream infections with positive repeat cultures (BSIPRC) in ECMO as well as clinical factors that may predict positive repeat cultures. METHODS: All BSIs in patients receiving ECMO at Brooke Army Medical Center between September 2012 and October 2021 were included in this study. BSIPRC was defined as re-isolation of the same organism on repeat blood cultures following an initial positive blood culture. RESULTS: A total of 60 patients developed 87 BSI (38.5 BSI per 1000 ECMO days). Of the 80 (92%) BSIs who had repeat blood cultures drawn, patients had BSIPRC in 35 (44%) of cases. Fever, leukocytosis, and vasopressor requirement on day of repeat culture were not associated with persistent positivity. There was no difference in survival to discharge for patients with BSIPRC as compared to single day BSI (58% vs. 63%, p = 0.78). 19% of patients with Gram-negative bacteremia had BSIPRC, and gram-negative bacteremia in general was associated with an 83% morality. CONCLUSIONS: There were no clinical findings that differentiated patients with BSIPRC from those who had a single day of positivity. BSI was associated with high mortality in patients with Gram-negative bacteremia. Given high incidence of positive repeat cultures being seen in Gram-negative BSIs, repeat blood cultures have utility for all BSIs in patients receiving ECMO.


Assuntos
Bacteriemia , Oxigenação por Membrana Extracorpórea , Sepse , Humanos , Oxigenação por Membrana Extracorpórea/efeitos adversos , Estudos de Coortes , Estudos Retrospectivos , Sepse/complicações , Bacteriemia/microbiologia
8.
bioRxiv ; 2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36711473

RESUMO

The Turkana people inhabit arid regions of east Africa-where temperatures are high and water is scarce-and they practice subsistence pastoralism, such that their diet is primarily composed of animal products. Working with Turkana communities, we sequenced 367 genomes and identified 8 regions putatively involved in adaptation to water stress and pastoralism. One of these regions includes a putative enhancer for STC1-a kidney-expressed gene involved in the response to dehydration and the metabolism of purine-rich foods such as red meat. We show that STC1 is induced by antidiuretic hormone in humans, is associated with urea levels in the Turkana themselves, and is under strong selection in this population (s∼0.041). This work highlights that partnerships with subsistence-level groups can lead to new models of human physiology with biomedical relevance.

9.
Biomech Model Mechanobiol ; 22(5): 1515-1530, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36652053

RESUMO

Non-invasive microstructural characterisation has the potential to determine the stability, or lack thereof, of atherosclerotic plaques and ultimately aid in better assessing plaques' risk to rupture. If linked with mechanical characterisation using a clinically relevant imaging technique, mechanically sensitive rupture risk indicators could be possible. This study aims to provide this link-between a clinically relevant imaging technique and mechanical characterisation within human atherosclerotic plaques. Ex vivo diffusion tensor imaging, mechanical testing, and histological analysis were carried out on human carotid atherosclerotic plaques. DTI-derived tractography was found to yield significant mechanical insight into the mechanical properties of more stable and more vulnerable microstructures. Coupled with insights from digital image correlation and histology, specific failure characteristics of different microstructural arrangements furthered this finding. More circumferentially uniform microstructures failed at higher stresses and strains when compared to samples which had multiple microstructures, like those seen in a plaque cap. The novel findings in this study motivate diagnostic measures which use non-invasive characterisation of the underlying microstructure of plaques to determine their vulnerability to rupture.


Assuntos
Placa Aterosclerótica , Humanos , Placa Aterosclerótica/diagnóstico por imagem , Placa Aterosclerótica/patologia , Imagem de Tensor de Difusão , Artérias Carótidas/patologia , Fatores de Risco
10.
Sci Adv ; 9(4): eadf0323, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36696503

RESUMO

We demonstrate experimentally that reflectionless scattering modes (RSMs), a generalized version of coherent perfect absorption, can be functionalized to perform reflectionless programmable signal routing. We achieve versatile programmability both in terms of operating frequencies and routing functionality with negligible reflection upon in-coupling, which avoids unwanted signal power echoes in radio frequency or photonic networks. We report in situ observations of routing functionalities like wavelength demultiplexing, including cases where multichannel excitation requires adapted coherent input wavefronts. All experiments are performed in the microwave domain based on the same irregularly shaped cavity with strong modal overlap that is massively parametrized by a 304-element-programmable metasurface. RSMs in our highly overdamped multiresonance transport problem are fundamentally intriguing because the simple critical coupling picture for reflectionless excitation of isolated resonances fails spectacularly. We show in simulation that the distribution of damping rates of scattering singularities broadens under strong absorption so that weakly damped zeros can be tuned toward functionalized RSMs.

11.
J Orthop ; 35: 126-133, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36471696

RESUMO

Introduction: Despite advancements in modern locking plate technology, distal humerus fractures in the elderly remain difficult to treat. A subset of fractures in this osteoporotic bone includes multiple, shallow articular fragments that renders fixation unreliable, precluding early motion and acceptable functional outcomes. Arthroplasty, in the form of either Total Elbow Arthroplasty (TEA) or Distal Humeral Hemiarthroplasty (DHH) are alternative treatment options in this cohort and are being increasingly used. Methods: This article reviews the use of TEA or DHH for acute distal humerus fracture, including patient selection, pre-operative planning, surgical approach, implant positioning, rehabilitation, outcomes and complications. Results: Arthroplasties are being increasingly used for acute distal humerus fractures, however they introduce potential complications not seen with fixation. Due care must be employed to correct implant positioning which is a function of implant rotation, implant length and implant sizing. We describe a robust technique for epicondyle repair in DHH and unlinked TEA to avoid instability. Outcomes of DHH and TEA for acute distal humerus fracture are encouraging, however further long-term outcome and comparative data regarding arthroplasty is required. Conclusions: Short to medium term outcomes demonstrate that both DHH and TEA are valuable options for selected patients, although attention to technique is required to minimise potential complications.

12.
Comput Struct Biotechnol J ; 21: 3459-3465, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38213888

RESUMO

The primary aim of this research was to investigate potential differences of breast tumor morphologies across African American and Caucasian racial groups by utilizing machine learning (ML) and artificial intelligence (AI) methods. While breast cancer disparities can partially be attributed to social determinants of health, tumor biology also contributes to survival outcomes. The rate of breast tumor growth is largely dependent on the extracellular matrix (ECM). Current research suggests the cellular components of the ECM may vary among racial and ethnic populations, and this may contribute to the incidence of cancer in African Americans. We utilized a supervised AI method to evaluate morphological differences between African American and Caucasian breast cancer tumors. Images used for analysis were downloaded from the Cancer Genome Atlas (TCGA) biorepository stored in the NIH Genomic Data Commons (GDC) data portal. We designed an ML classifier using the AlexNet model provided in PyTorch's torchvision package. The model was pre-trained and adapted via transfer learning resulting in a classification accuracy of 92.1% when using our breast cancer tumor image database split into 80% of training set and 20% of testing set. We interpreted the results of the AlexNet and ResNet50 models using LIME and saliency mapping as the explainers. Based on the images from our bi-racial testing set, this study confirmed significant variations of tumor and ECM regions in the different racial groups evaluated. Based on these findings, further analysis and characterization may provide new insight into disparities associated with the incidence of breast cancer.

13.
Forensic Sci Int Genet ; 56: 102610, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34735939

RESUMO

The recovery and analysis of genetic material obtained from thermally altered human bones and teeth are increasingly important to forensic investigations, especially in cases where soft-tissue identification is no longer possible. Although little is known about how these fire-related processes affect DNA degradation over time, next-generation sequencing technology in combination with traditional osteobiographical applications may provide us clues to these questions. In this study, we compare whole mitochondrial genome data generated using two different DNA extraction methods from 27 thermally altered samples obtained from fire victims (Maricopa County, Arizona) . DNA extracts were converted to double-stranded DNA libraries and enriched for whole mitochondrial DNA (mtDNA) using synthetic biotinylated RNA baits, then sequenced on an Illumina MiSeq. We processed the mitochondrial data using an in-house computational pipeline (MitoPipe1.0) composed of ancient DNA and modern genomics applications, then compared the resulting information across the two extraction types and five burn categories. Our analysis shows that DNA fragmentation increases with temperature, but that the acute insult from fire combined with the lack of water is insufficient to produce 5' and 3' terminal deamination characteristic of ancient DNA. Our data also suggest an acute and significant point of DNA degradation between 350 °C and 550 °C, and that the likelihood of generating high quality mtDNA haplogroup calls decreases significantly at temperatures > 550 °C. This research is part of a concerted effort to understand how fire affects our ability to generate genetic profiles suitable for forensic identification purposes.


Assuntos
Genoma Mitocondrial , Dente , DNA Mitocondrial/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Análise de Sequência de DNA
14.
J Pain Res ; 14: 3359-3376, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34737631

RESUMO

PURPOSE: Several articles have claimed that complex regional pain syndrome (CRPS) does not exist. Although a minority view, it is important to understand the arguments presented in these articles. We conducted a systematic literature search to evaluate the methodological quality of articles that claim CRPS does not exist. We then examined and refuted the arguments supporting this claim using up-to-date scientific literature on CRPS. METHODS: A systematic search was conducted in MEDLINE, EMBASE and Cochrane CENTRAL databases. Inclusion criteria for articles were (a) a claim made that CRPS does not exist or that CRPS is not a distinct diagnostic entity and (b) support of these claims with subsequent argument(s). The methodological quality of articles was assessed if possible. RESULTS: Nine articles were included for analysis: 4 narrative reviews, 2 personal views, 1 letter, 1 editorial and 1 case report. Seven points of controversy were used in these articles to argue that CRPS does not exist: 1) disagreement with the label "CRPS"; 2) the "unclear" pathophysiology; 3) the validity of the diagnostic criteria; 4) CRPS as a normal consequence of immobilization; 5) the role of psychological factors; 6) other identifiable causes for CRPS symptoms; and 7) the methodological quality of CRPS research. CONCLUSION: The level of evidence for the claim that CRPS does not exist is very weak. Published accounts concluding that CRPS does not exist, in the absence of primary evidence to underpin them, can harm patients by encouraging dismissal of patients' signs and symptoms.

15.
Science ; 373(6560): 1261-1265, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34516794

RESUMO

Recently, exceptional points, a degeneracy of open wave systems, have been observed in photonics, acoustics, and electronics. They have mainly been realized as a degeneracy of resonances; however, a degeneracy associated with the absorption of waves can exhibit distinct and interesting physical features. Here, we demonstrate such an absorbing exceptional point by engineering degeneracies in the absorption spectrum of dissipative optical microcavities. We experimentally distinguished the conditions to realize an absorbing exceptional point versus a resonant exceptional point. Furthermore, when the optical loss was tuned to achieve perfect absorption at an absorbing exceptional point, we observed its signature, an anomalously broadened line shape in the absorption spectrum. The distinct scattering properties of the absorbing exceptional point create opportunities for both fundamental study and applications of non-Hermitian degeneracies.

16.
Proc Natl Acad Sci U S A ; 118(3)2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33397810

RESUMO

Polarization of optical fields is a crucial degree of freedom in the all-optical analogue of electromagnetically induced transparency (EIT). However, the physical origins of EIT and polarization-induced phenomena have not been well distinguished, which can lead to confusion in associated applications such as slow light and optical/quantum storage. Here we study the polarization effects in various optical EIT systems. We find that a polarization mismatch between whispering gallery modes in two indirectly coupled resonators can induce a narrow transparency window in the transmission spectrum resembling the EIT lineshape. However, such polarization-induced transparency (PIT) is distinct from EIT: It originates from strong polarization rotation effects and shows a unidirectional feature. The coexistence of PIT and EIT provides additional routes for the manipulation of light flow in optical resonator systems.

17.
Food Sci Technol Int ; 27(6): 528-538, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33222551

RESUMO

The effect of cooking on the levels of bioactive compounds (oligosaccharides, polyphenols and saponins, and vicine/convicine for faba bean only) were examined in a wide range of Canadian pulses. The total oligosaccharide concentrations were reduced ∼40% for chickpea, 11-81% for lentils, 41-43% for faba beans, 10-51% for beans, and 20-44% for peas. Individual oligosaccharides, raffinose, ciceritol, stachyose and verbascose, increased or decreased in the cooked samples depending on each pulse sample. Cooking reduced the total polyphenol content by 13-25% for chickpeas, 0-83% for lentils, 47-54% for faba beans, 47-54% for beans, and 48-70% for peas. And, the total saponin concentrations were reduced by 11-30% for chickpeas, 0-40% for lentils, 32-46% for beans, 14-30% for peas and increased by 8-26% in faba bean. The vicine and convicine levels in faba bean were reduced by 26-38% with cooking. The reduction in bioactive compounds after cooking depended on the specific compound and specific type of pulse. This large analyses of 20 different pulse samples allows for comparison between and within different types of pulses.


Assuntos
Fabaceae , Vicia faba , Canadá , Culinária , Sementes
18.
J Dairy Sci ; 104(1): 501-524, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33131806

RESUMO

The objectives of the study were to use a heat stress scoring system to evaluate the severity of heat stress on dairy cows using different heat abatement techniques. The scoring system ranged from 1 to 4, where 1 = no heat stress; 2 = mild heat stress; 3 = severe heat stress; and 4 = moribund. The accuracy of the scoring system was then predicted using 3 machine learning techniques: logistic regression, Gaussian naïve Bayes, and random forest. To predict the accuracy of the scoring system, these techniques used factors including temperature-humidity index, respiration rate, lying time, lying bouts, total steps, drooling, open-mouth breathing, panting, location in shade or sprinklers, somatic cell score, reticulorumen temperature, hygiene body condition score, milk yield, and milk fat and protein percent. Three different treatments, namely, portable shade structure, portable polyvinyl chloride pipe sprinkler system, or control with no heat abatement, were considered, where each treatment was replicated 3 times with 3 second-trimester lactating cows. Results indicate that random forest outperformed the other 2 methods, with respect to both accuracy and precision, in predicting the sprinkler group's score. Both logistic regression and random forest were consistent in predicting scores for control, shade, and combined groups. The mean probability of predicting non-heat-stressed cows was highest for cows in the sprinkler group. Finally, the logistic regression method worked best for predicting heat-stressed cows in control, shade, and combined. The insights gained from these results could aid dairy producers to detect heat stress before it becomes severe, which could decrease the negative effects of heat stress, such as milk loss.


Assuntos
Doenças dos Bovinos/diagnóstico , Indústria de Laticínios , Transtornos de Estresse por Calor/veterinária , Aprendizado de Máquina , Animais , Teorema de Bayes , Temperatura Corporal , Bovinos , Feminino , Transtornos de Estresse por Calor/diagnóstico , Temperatura Alta , Lactação , Leite , Taxa Respiratória , Temperatura
19.
Sci Rep ; 10(1): 20718, 2020 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-33244026

RESUMO

This study investigates diffusion tensor imaging (DTI) for providing microstructural insight into changes in arterial tissue by exploring how cell, collagen and elastin content effect fractional anisotropy (FA), mean diffusivity (MD) and tractography. Five ex vivo porcine carotid artery models (n = 6 each) were compared-native, fixed native, collagen degraded, elastin degraded and decellularised. Vessels were imaged at 7 T using a DTI protocol with b = 0 and 800 s/mm2 and 10 isotopically distributed directions. FA and MD were evaluated in the vessel media and compared across models. FA values measured in native (p < 0.0001), fixed native (p < 0.0001) and collagen degraded (p = 0.0018, p = 0.0016, respectively) were significantly higher than those in elastin degraded and decellularised arteries. Native and fixed native had significantly lower MD values than elastin degraded (p < 0.0001) and decellularised tissue (p = 0.0032, p = 0.0003, respectively). Significantly lower MD was measured in collagen degraded compared with the elastin degraded model (p = 0.0001). Tractography yielded helically arranged tracts for native and collagen degraded vessels only. FA, MD and tractography were found to be highly sensitive to changes in the microstructural composition of arterial tissue, specifically pointing to cell, not collagen, content as the dominant source of the measured anisotropy in the vessel wall.


Assuntos
Artérias Carótidas/fisiologia , Imagem de Tensor de Difusão/métodos , Animais , Anisotropia , Artérias Carótidas/metabolismo , Colágeno/metabolismo , Elastina/metabolismo , Suínos
20.
J Dairy Sci ; 103(10): 9667-9675, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32713700

RESUMO

The southeastern United States experiences an extended hot season with a high environmental temperature and relative humidity. With increasing global temperatures, managing dairy cattle in regions with tropical, subtropical, and Mediterranean climates is becoming an increasing challenge. Heat-stressed cows will decrease feed intake, decrease productivity, and increase respiration rate in an attempt to maintain internal body temperature. Temperature-humidity index (THI) is a unitless value that has been used to measure the magnitude of heat stress on dairy cows. Many researchers have studied the THI threshold at which dairy cattle begin to experience heat stress. When housing cows in a confinement setting, a pasture-based setting, or a combination of the two, the appropriate heat abatement should be implemented to allow cows to perform to their potential and to improve overall animal welfare. This review summarizes heat abatement strategies that have been studied to reduce the negative effects of heat stress.


Assuntos
Doenças dos Bovinos/prevenção & controle , Indústria de Laticínios/métodos , Transtornos de Estresse por Calor/veterinária , Animais , Bovinos , Doenças dos Bovinos/fisiopatologia , Feminino , Transtornos de Estresse por Calor/fisiopatologia , Transtornos de Estresse por Calor/prevenção & controle , Abrigo para Animais , Sudeste dos Estados Unidos
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