RESUMO
Recent measurements of microwave and x-ray emission during edge localized mode (ELM) activity in tokamak plasmas provide a fresh perspective on ELM physics. It is evident that electron kinetics, which are not incorporated in standard (fluid) models for the instability that drives ELMs, play a key role in the new observations. These effects should be included in future models for ELMs and the ELM cycle. The observed radiative effects paradoxically imply acceleration of electrons parallel to the magnetic field combined with rapid acquisition of perpendicular momentum. It is shown that this paradox can be resolved by the action of the anomalous Doppler instability which enables fast collective radiative relaxation, in the perpendicular direction, of electrons accelerated in the parallel direction by inductive electric fields generated by the initial ELM instability.
RESUMO
The influence of temperament on the alteration of metabolic parameters in response to a lipopolysaccharide(LPS) challenge was investigated. Brahman bulls were selected based on temperament score. Bulls (10 months; 211±5kg BW; n = 6, 8 and 7 for Calm, Intermediate and Temperamental groups, respectively) were fitted with indwelling jugular catheters to evaluate peripheral blood concentrations of glucose, blood urea nitrogen (BUN),non-esterified fatty acids (NEFA), insulin, epinephrine and cortisol before and after LPS administration (0.5 µg/kg BW LPS). Feed intake was also recorded. Intermediate bulls consumed more feed than the Temperamental bulls during the challenge (p = 0.046). Pre-LPS glucose (p = 0.401) and BUN (p = 0.222) did not differ among the temperament groups. However, pre-LPS insulin (p = 0.023) was lower, whereas pre-LPS NEFA (p < 0.001),cortisol (p < 0.001) and epinephrine (p < 0.001) were greater in Temperamental than in Calm and Intermediate bulls. Post-LPS glucose was increased in Calm and Intermediate bulls but not in Temperamental bulls(p < 0.001). Insulin concentrations post-LPS were greater in Calm than in Intermediate and Temperamental bulls (p < 0.001). Concentrations of NEFA post-LPS were greater in Temperamental than in Calm and Intermediate bulls (p < 0.001). Serum BUN concentration increased post-LPS, with values being greater in Calm and Intermediate than in Temperamental bulls (p = 0.012). Collectively, these data demonstrate that animal temperament is related to the metabolic responses of Brahman bulls following a provocative endotoxin challenge.Specifically, Temperamental bulls may preferentially utilize an alternate energy source (i.e. NEFA) to a greater degree than do bulls of Calm and Intermediate temperaments. The use of circulating NEFA from lipolysis may reduce the negative metabolic consequences of an immune response by allowing for a prompt answer to increasing energy demands required during immunological challenge, compared with the time required for glycogenolysis and gluconeogenesis.
Assuntos
Comportamento Animal/fisiologia , Bovinos/metabolismo , Bovinos/psicologia , Lipopolissacarídeos/toxicidade , Temperamento/fisiologia , Animais , Comportamento Animal/efeitos dos fármacos , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Nitrogênio da Ureia Sanguínea , Bovinos/sangue , Ingestão de Alimentos/efeitos dos fármacos , Ácidos Graxos não Esterificados/sangue , Insulina/sangue , Masculino , Temperamento/efeitos dos fármacosRESUMO
The Diving Committee of the Undersea and Hyperbaric Medical Society has reviewed available evidence in relation to the medical aspects of rescuing a submerged unresponsive compressed-gas diver. The rescue process has been subdivided into three phases, and relevant questions have been addressed as follows. Phase 1, preparation for ascent: If the regulator is out of the mouth, should it be replaced? If the diver is in the tonic or clonic phase of a seizure, should the ascent be delayed until the clonic phase has subsided? Are there any special considerations for rescuing rebreather divers? Phase 2, retrieval to the surface: What is a "safe" ascent rate? If the rescuer has a decompression obligation, should they take the victim to the surface? If the regulator is in the mouth and the victim is breathing, does this change the ascent procedures? If the regulator is in the mouth, the victim is breathing, and the victim has a decompression obligation, does this change the ascent procedures? Is it necessary to hold the victim's head in a particular position? Is it necessary to press on the victim's chest to ensure exhalation? Are there any special considerations for rescuing rebreather divers? Phase 3, procedure at the surface: Is it possible to make an assessment of breathing in the water? Can effective rescue breaths be delivered in the water? What is the likelihood of persistent circulation after respiratory arrest? Does the recent advocacy for "compression-only resuscitation" suggest that rescue breaths should not be administered to a non-breathing diver? What rules should guide the relative priority of in-water rescue breaths over accessing surface support where definitive CPR can be started? A "best practice" decision tree for submerged diver rescue has been proposed.
Assuntos
Reanimação Cardiopulmonar/normas , Mergulho/efeitos adversos , Mergulho/normas , Afogamento Iminente/prevenção & controle , Trabalho de Resgate/normas , Inconsciência , Algoritmos , Reanimação Cardiopulmonar/métodos , Árvores de Decisões , Epilepsia Tônico-Clônica/fisiopatologia , Cabeça , Humanos , Parada Cardíaca Extra-Hospitalar/prevenção & controle , Posicionamento do Paciente/métodos , Posicionamento do Paciente/normas , Trabalho de Resgate/métodos , Insuficiência Respiratória/prevenção & controleRESUMO
Between 1997 and 2008, the number of general surgeons in North Carolina increased and shifted demographically, geographically, and by specialty. However, surgeon numbers--overall and by specialty--do not appear to have increased as quickly or to have shifted in the same ways as North Carolina's general population.
Assuntos
Cirurgia Geral , Mão de Obra em Saúde/tendências , Cirurgia Geral/educação , Humanos , North Carolina , Crescimento Demográfico , Faculdades de MedicinaRESUMO
Incorporation of the alpha5 nicotinic acetylcholine receptor (nAChR) subunit can greatly influence nAChR function without altering receptor number. Although few animal studies have assessed the role of the alpha5 nAChR in nicotine-mediated behaviors, recent evidence suggests an association between polymorphisms in the alpha5 nAChR gene and nicotine dependence phenotypes in humans. Thus, additional studies are imperative to elucidate the role and function of the alpha5 nAChR subunit in nicotine dependence. Using alpha5(-/-) mice, the current study aimed to examine the role of alpha5 nAChRs in the initial pharmacological effects of nicotine, nicotine reward using the conditioned place preference model, and the discriminative effects of nicotine using a two-lever drug discrimination model. (86)Rb(+) efflux and (125)I-epibatidine binding assays were conducted to examine the effect of alpha5 nAChR subunit deletion on expression and activity of functional nAChRs. Results show that alpha5(-/-) mice are less sensitive to the initial effects of nicotine in antinociception, locomotor activity, and hypothermia measures and that the alpha5 nAChR is involved in nicotine reward. Alternatively, alpha5(-/-) mice did not differ from wild-type littermates in sensitivity to the discriminative stimulus effects of nicotine. Furthermore, deletion of the alpha5 nAChR subunit resulted in a statistically significant decrease in function in the thalamus and hindbrain, but the decreases noted in spinal cord were not statistically significant. Receptor number was unaltered in all areas tested. Taken together, results of the study suggest that alpha5 nAChRs are involved in nicotine-mediated behaviors relevant to development of nicotine dependence.
Assuntos
Comportamento Animal/efeitos dos fármacos , Nicotina/farmacologia , Receptores Nicotínicos/fisiologia , Analgésicos Opioides/farmacologia , Animais , Temperatura Corporal , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Relação Dose-Resposta a Droga , Hipotermia/induzido quimicamente , Hipotermia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Morfina/farmacologia , Atividade Motora/efeitos dos fármacos , Agonistas Nicotínicos/farmacologia , Dor/metabolismo , Limiar da Dor/efeitos dos fármacos , Ligação Proteica , Receptores Nicotínicos/genética , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismoRESUMO
To test the influence of transportation stress and temperament on shedding of Escherichia coli O157:H7, cattle (n=150) were classified at various stages of production as Excitable, Intermediate or Calm based on a variety of disposition scores. Presence of E. coli O157:H7 was determined by rectal swabs from live animals and from colons collected postmortem. Percentage of cattle shedding E. coli O157:H7 at arrival at the feedlot was approximately equal among temperament groups. Before shipment to the processing facility, a higher (P=0.03) proportion of cattle from the Calm group shed E. coli O157:H7 compared to the other temperament groups. When pooled across all sampling periods, cattle from the Calm group had a greater percentage test positive for E. coli O157:H7. Neither the acute stressor of transportation nor a more excitable temperament led to increased shedding of E. coli O157:H7 in cattle.
RESUMO
Diving fatalities causes were investigated in 947 recreational open-circuit scuba diving deaths from 1992-2003. Where possible, cases were classified at each step of a four step sequence: trigger, disabling agent, disabling injury, cause of death (COD). The most frequent adverse events within each step were: (a) triggers 41% insufficient gas, 20% entrapment, 15% equipment problems; (b) disabling agents--55% emergency ascent, 27% insufficient gas, 13% buoyancy trouble; (c) disabling injuries--33% asphyxia, 29% arterial gas embolism (AGE), 26% cardiac incidents; and (d) COD--70% drowning, 14% AGE, 13% cardiac incidents. We concluded that disabling injuries were more relevant than COD as drowning was often secondary to a disabling injury. Frequencies and/ or associations with risk factors were investigated for each disabling injury by logistic regression. (The reference group for each injury was all other injuries.) Frequencies and/or associations included: (a) asphyxia--40% entrapment (Odds Ratio, OR > or = 30), 32% insufficient gas (OR = 15.9), 17% buoyancy trouble, 15% equipment trouble (OR = 4.5), 11% rough water, drysuit (OR = 4.1), female gender (OR = 2.1); (b) AGE--96% emergency ascent (OR > or = 30), 63% insufficient gas, 17% equipment trouble, 9% entrapment; (c) cardiac incidents--cardiovascular disease (OR = 10.5), age > 40 (OR = 5.9). Minimizing the frequent adverse events would have the greatest impact on reducing diving deaths.
Assuntos
Causas de Morte , Mergulho/efeitos adversos , Adolescente , Adulto , Idoso , Ar , Asfixia/etiologia , Asfixia/mortalidade , Causalidade , Doença da Descompressão/complicações , Doença da Descompressão/mortalidade , Mergulho/lesões , Afogamento/etiologia , Afogamento/mortalidade , Falha de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Análise de Regressão , Fatores de Risco , Inconsciência/complicações , Inconsciência/mortalidade , Ferimentos e Lesões/mortalidade , Adulto JovemRESUMO
Low-temperature plasmas (LTPs) have a proven bactericidal activity governed by the generated reactive oxygen and nitrogen species (RONS) that target microbial cell components. However, RONS also interact with biomolecules in the environment. Here we assess the impact of these interactions upon exposure of liquid suspensions with variable organic content to an atmospheric-pressure dielectric barrier discharge plasma jet. Salmonella enterica serovar Typhimurium viability in the suspension was reduced in the absence [e.g., phosphate buffered saline (PBS)], but not in the presence of (high) organic content [Dulbecco's Modified Eagle's Medium (DMEM), DMEM supplemented with foetal calf serum, and Lysogeny Broth]. The reduced viability of LTP-treated bacteria in PBS correlated to a loss of membrane integrity, whereas double-strand DNA breaks could not be detected in treated single cells. The lack of bactericidal activity in solutions with high organic content correlated with a relative decrease of â¢OH and O3/O2(a1[Formula: see text])/O, and an increase of H2O2 and [Formula: see text] in the plasma-treated solutions. These results indicate that the redox reactions of LTP-generated RONS with nontarget biomolecules resulted in a RONS composition with reduced bactericidal activity. Therefore, the chemical composition of the bacterial environment should be considered in the development of LTP for antimicrobial treatment, and may affect other biomedical applications as well.
RESUMO
Previous trials of flying at 8,000 ft after a single 60 fsw, 55 min no-stop air dive found low decompression sickness (DCS) risk for a 11:00 preflight surface interval (PFSI). Repetitive 60 fsw no-stop dives with 75 and 95 min total bottom times found 16:00. Trials reported here investigated PFSIs for a 60 fsw, 40 min no-stop dive and a 60 fsw, 120 min decompression dive. The 40 min trials began with a 12:05 PFSI (USN guideline) which was incrementally reduced to 0:05 (three DCS incidents in 281 trials). The 120 min trials began with a 22:46 PFSI (USN guideline) which was reduced to 2:00 (nine incidents in 281 trials); 2:00 was rejected with six incidents. Low-risk PFSIs for the 40 min dive were nearly 12 hours shorter than for the 55 min dive, and low-risk PFSIs for the single 120 min decompression dive were 12 hours shorter than for the 75-95 min repetitive dives. With the dry, resting conditions of these dives, low-risk PFSIs appeared to be sensitive to dive profile characteristics such as bottom time, repetitive diving, and decompression stops. Whether this is so for wet, working dives is unknown.
Assuntos
Medicina Aeroespacial , Doença da Descompressão/etiologia , Mergulho/fisiologia , Adolescente , Adulto , Descompressão , Doença da Descompressão/diagnóstico por imagem , Doença da Descompressão/terapia , Exantema/etiologia , Feminino , Cardiopatias/diagnóstico por imagem , Cardiopatias/etiologia , Cardiopatias/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Fatores de Tempo , UltrassonografiaRESUMO
INTRODUCTION: First aid oxygen (FAO2) has been widely used as an emergency treatment for diving injuries, but there are few studies supporting its efficacy. METHODS: 2,231 sequential diving injury reports collected by the Divers Alert Network (DAN) Injury database from 1998 to 2003 were examined. RESULTS: 47% (1,045) of cases received FAO2. The median time to FAO2 treatment after surfacing was four hours and after symptom onset was 2.2 hours. Persistent complete relief (14%) or improvement (51%) was seen with FAO2 alone (65% overall response; n = 330). After one recompression treatment 67% of FAO2 patients reported complete relief compared to 58% of the no FAO2 group (OR = 1.5, 95% CI = 1.2 -1.8). FAO2 given at any time after surfacing significantly reduced the odds of multiple recompression treatments (OR = 0.83, 0.70-0.98). When FAO2 was given within 4 hours of surfacing, the OR decreased to 0.50 (0.36-0.69) yielding a number needed to treat of 6. Case severity affected urgency of FAO2 treatment. Individuals with more prominent symptoms received prompt treatment. Cardiopulmonary, skin, and serious neurological symptoms had shorter delays to FAO2 (p < 0.001). CONCLUSIONS: FAO2 increased recompression efficacy and decreased the number of recompression treatments required if given within four hours after surfacing.
Assuntos
Doença da Descompressão/terapia , Mergulho/efeitos adversos , Primeiros Socorros/métodos , Oxigenoterapia/métodos , Bases de Dados Factuais , Humanos , Modelos Logísticos , Razão de Chances , Estudos Retrospectivos , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do TratamentoRESUMO
This study examined the relationship of prenatal transportation stress (PNS) with exogenous GnRH-induced LH and testosterone secretion in sexually mature Brahman bulls. Brahman cows (n = 96; 48 were stressed by transportation at 5 stages of gestation and 48 were controls) produced a calf crop of 85 calves. All bulls (n = 46) from this calf crop were electroejaculated every 2 wk beginning at a scrotal circumference of 24 cm until sexual maturity (SM; i.e., 500 million sperm/ejaculate). The initial 11 control and 12 PNS bulls to reach SM were selected for the experiment. Within 7-21 d after reaching SM, bulls were fitted with jugular cannulas, from which blood samples were collected at 15-min intervals for 6 h prior to exogenous GnRH administration (10 ng/kg BW; i.v.) and for 6 h after GnRH. Serum concentrations of LH, testosterone, and cortisol were determined by RIA. Age and body weight did not differ ( > 0.1) between PNS and control bulls at the time of the experiment. All bulls responded similarly to exogenous GnRH, indicating no influence of PNS on LH or testosterone response to GnRH. More ( < 0.01) PNS (9 of 11) than control (3 of 12) bulls exhibited an endogenous pre-GnRH LH pulse, and more ( = 0.02) PNS (9 of 11) than control bulls (4 of 12) exhibited a pre-GnRH testosterone response to LH. The average concentration of testosterone during the 60 min (time -60, -45, -30, -15, and 0 min relative to GnRH) immediately preceding GnRH, tended to be greater ( = 0.07) in PNS (1.46 ± 0.30 ng/mL) than control (0.68 ± 0.28 ng/mL) bulls. During that time span serum cortisol was lower ( < 0.01) in PNS (4.00 ± 0.91 ng/mL) than control (7.8 ± 0.87 ng/mL) bulls. A treatment by time interaction ( = 0.03) affected testosterone concentrations from time -240 to 360 min relative to GnRH. Results from this study indicate that PNS did not affect pituitary responsiveness to GnRH or testicular responsiveness to GnRH-induced LH secretion.
Assuntos
Bovinos/fisiologia , Hormônio Liberador de Gonadotropina/farmacologia , Hormônio Luteinizante/metabolismo , Testosterona/sangue , Meios de Transporte , Animais , Peso Corporal , Feminino , Hidrocortisona , Masculino , Hipófise/efeitos dos fármacos , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Estresse Fisiológico , Testículo/efeitos dos fármacos , Testosterona/metabolismoRESUMO
Three groups of steers (A, B, C) were used to study the effect of temperament (Calm, Intermediate, and Excitable) on meat quality. Temperament was based on exit velocity, pen scores, and chute scores. Temperament traits were consistent across evaluations, and values decreased (P<0.05) in magnitude over time. Increasing excitability was associated with higher (P<0.05) serum cortisol concentrations. Carcasses from cattle with calm temperaments had higher (P<0.05) 0.5h postmortem pH values than those from Intermediate and Excitable cattle (0.1 and 0.2 units, respectively). Group C Excitable steers had higher (P<0.05) WBS values than the calmer Group C steers. This trend was observed in Group A steers, although the values were not statistically different. Correlations were highest between temperament values and tenderness after 21d. Temperament influences tenderness, although the mechanism is not clear.
RESUMO
The Synthetic Aperture Microwave Imaging (SAMI) system is a novel diagnostic consisting of an array of 8 independently phased antennas. At any one time, SAMI operates at one of the 16 frequencies in the range 10-34.5 GHz. The imaging beam is steered in software post-shot to create a picture of the entire emission surface. In SAMI's active probing mode of operation, the plasma edge is illuminated with a monochromatic source and SAMI reconstructs an image of the Doppler back-scattered (DBS) signal. By assuming that density fluctuations are extended along magnetic field lines, and knowing that the strongest back-scattered signals are directed perpendicular to the density fluctuations, SAMI's 2-D DBS imaging capability can be used to measure the pitch of the edge magnetic field. In this paper, we present preliminary pitch angle measurements obtained by SAMI on the Mega Amp Spherical Tokamak (MAST) at Culham Centre for Fusion Energy and on the National Spherical Torus Experiment Upgrade at Princeton Plasma Physics Laboratory. The results demonstrate encouraging agreement between SAMI and other independent measurements.
RESUMO
This experiment examined the relationship between prenatal stress and subsequent calf temperament through weaning. The prenatal stressor used was repeated transportation of pregnant Brahman cows for 2 h at 60 ± 5, 80 ± 5, 100 ± 5, 120 ± 5, and 140 ± 5 d of gestation. Prenatally stressed calves ( = 41) were compared with controls ( = 44; dams did not undergo transportation during pregnancy) from 2 wk of age until weaning (average age at weaning = 174.8 ± 1.3 d). Temperament was defined by pen score (PS; 1 = calm and 5 = excitable), exit velocity (EV; m/sec), and temperament score (TS; (PS + EV)/2) and was recorded for each calf on d -168, -140, -112, -84, -56, -28, and 0 relative to weaning (d 0 = weaning). Cortisol concentrations were determined in serum samples obtained on d -168, -140, -28, and 0 relative to weaning. Birth weight and weaning weight were not different between treatment groups ( > 0.1). Pen score was greater ( = 0.03) in prenatally stressed calves (2.84 ± 0.21) relative to controls (2.31 ± 0.21). Exit velocity was greater ( < 0.01) in prenatally stressed calves (2.1 ± 0.14 m/sec) than in controls (1.61 ± 0.14 m/sec). Exit velocity was affected by a treatment × calf sex interaction ( = 0.04) and was greater in prenatally stressed females. Exit velocity was also affected by day ( < 0.0001). Temperament score was greater ( = 0.01) in prenatally stressed calves (2.45 ± 0.16) than in controls (1.95 ± 0.16). Temperament score was affected by day ( < 0.01). Basal cortisol concentrations were greater ( = 0.04) in prenatally stressed calves (15.87 ± 1.04 ng/mL) than in controls (13.42 ± 1.03 ng/mL). Basal cortisol concentrations were greater ( < 0.01) in females (16.61 ± 1.06 ng/mL) than in males (12.68 ± 1.02 ng/mL). Cortisol concentrations were positively correlated ( < 0.01) with PS ( = 0.55, < 0.01), EV ( = 0.4, < 0.01), and TS ( = 0.55, < 0.01). Overall, suckling Brahman calves that were prenatally stressed were more temperamental and had greater circulating serum concentrations of cortisol than control calves.
Assuntos
Animais Lactentes/fisiologia , Bovinos/fisiologia , Hidrocortisona/sangue , Animais , Animais Recém-Nascidos/fisiologia , Animais Recém-Nascidos/psicologia , Animais Lactentes/sangue , Animais Lactentes/psicologia , Peso ao Nascer , Bovinos/sangue , Bovinos/psicologia , Feminino , Masculino , Gravidez , Fatores Sexuais , Estresse Fisiológico , Estresse Psicológico , Temperamento , Meios de Transporte , DesmameRESUMO
Cattle temperament, defined as the reactivity of cattle to humans or novel environments, can greatly influence several physiological systems in the body, including immunity, stress, and most recently discovered, metabolism. Greater circulating concentrations of nonesterified fatty acids (NEFAs) found in temperamental cattle suggest that temperamental cattle are metabolically different than calm cattle. Further, elevated NEFA concentrations have been reported to influence insulin sensitivity. Therefore, the objective of this study was to determine whether cattle temperament would influence the metabolic response to a glucose tolerance test (GTT) and insulin sensitivity test (IST). Angus-cross steers (16 calm and 15 temperamental; 216 ± 6 kg BW) were selected based on temperament score measured at weaning. On day 1, steers were moved into indoor stanchions to allow measurement of individual ad libitum feed intake. On day 6, steers were fitted with indwelling rectal temperature probes and jugular catheters. At 9 AM on day 7, steers received the GTT (0.5-mL/kg BW of a 50% dextrose solution), and at 2 PM on day 7, steers received the IST (2.5 IU bovine insulin/kg BW). Blood samples were collected and serum isolated at -60, -45, -30, -15, 0, 10, 20, 30, 45, 60, 90, 120, and 150 min relative to each challenge. Serum was stored at -80°C until analyzed for cortisol, glucose, NEFA, and blood urea nitrogen concentrations. All variables changed over time (P < 0.01). For the duration of the study, temperamental steers maintained greater (P < 0.01) serum NEFA and less (P ≤ 0.01) serum blood urea nitrogen and insulin sensitivity (calculated using Revised Quantitative Insulin Sensitivity Check Index) compared with calm steers. During the GTT, temperamental steers had greater (P < 0.01) serum glucose, yet decreased (P = 0.03) serum insulin and (P < 0.01) serum insulin: serum glucose compared to calm cattle. During the IST, temperamental steers had greater (P < 0.01) serum insulin and a greater (P < 0.01) serum insulin: serum glucose as compared with calm steers. These data demonstrate that differences exist in the manner in which temperamental steers respond to glucose and insulin, potentially a result of elevated serum NEFA concentrations, which may result in changes in utilization and redistribution of energy in temperamental vs calm cattle.
Assuntos
Bovinos/metabolismo , Bovinos/psicologia , Teste de Tolerância a Glucose/veterinária , Resistência à Insulina/fisiologia , Temperamento/fisiologia , Animais , Glicemia/análise , Nitrogênio da Ureia Sanguínea , Metabolismo Energético/fisiologia , Ácidos Graxos não Esterificados/sangue , Hidrocortisona/sangue , MasculinoRESUMO
The synthetic aperture microwave imaging diagnostic has been operating on the MAST experiment since 2011. It has provided the first 2D images of B-X-O mode conversion windows and showed the feasibility of conducting 2D Doppler back-scattering experiments. The diagnostic heavily relies on field programmable gate arrays to conduct its work. Recent successes and newly gained experience with the diagnostic have led us to modify it. The enhancements will enable pitch angle profile measurements, O and X mode separation, and the continuous acquisition of 2D DBS data. The diagnostic has also been installed on the NSTX-U and is acquiring data since May 2016.
RESUMO
The objective of this study was to investigate the impact of oral meloxicam (MEL) and long-distance transportation on cell-mediated immunity (CMI) in preconditioned steers receiving a booster vaccination on arrival. We hypothesized that steers treated with MEL at 1mg/kg body weight, 6h before night-time transport, would be less immunocompromised on arrival (day 0) and after 7days, and that CMI following vaccination with a modified live bovine viral diarrhea virus (BVDV) recall antigen would be increased. Brahman crossbreed steers, 13-17 months of age (n=87), were randomly assigned to one of four treatment groups: MEL, transported (MTR) (n=22), MEL, non-transported (MNT) (n=22), lactose placebo, transported (CTR) (n=21), and lactose placebo, non-transported (CNT) (n=22). MTR and CTR steers were transported for approximately 16h non-stop on a truck from Mississippi to Iowa (approximately 1300km), whereas steers in the MNT and CNT groups remained in Mississippi as non-transported controls. Body weight was measured and jugular blood was collected at -1, 0, and 7days from all steers at the same time, regardless of location. Multi-parameter flow cytometry (MP-FCM) was used to identify T-cell subsets and detect the expression of three activation markers (CD25 [interleukin (IL)-2 receptor], intracellular interferon-gamma [IFNγ], and IL-4) after in vitro stimulation with BVDV recall antigen. Plasma cortisol concentration was measured on day -1, 0, and 7 as a marker of transport-associated stress. Serum antibody titer to BVDV was assessed on day -1 and day 7 post-booster vaccination. Whole-blood samples were analyzed using MP-FCM on days 0 and 7. Results were log transformed and analyzed using repeated measures of analysis of variance. Compared with non-transported controls, transport led to an increase in BVDV-induced expression of CD25, IFNγ, and IL-4 in CD4(+), CD8(+), and γδ(+) T-cell subsets (P<0.05). MEL treatment mitigated the transportation-associated increase in CD25 expression by peripheral blood mononuclear cells (PBMCs), CD4(+), and γδ(+) T cells. CMI outputs for the MTR group were less than those of the CTR group (P<0.05); however, the MTR and NT groups did not differ (P>0.10). A treatment*transport interaction was noted for the increase in IL-4 expression by CD8(+) T cells after transport, with a significant difference between the CTR and MTR groups at day 7. In conclusion, the use of oral MEL prior to transport appears to have inhibitory or homeostatic effects, but further research is needed to validate the effect of MEL treatment on specific T-cell subsets in transported cattle.
Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Bovinos/imunologia , Vírus da Diarreia Viral Bovina/imunologia , Tiazinas/administração & dosagem , Tiazóis/administração & dosagem , Vacinas Virais/administração & dosagem , Animais , Anti-Inflamatórios não Esteroides/sangue , Anticorpos Antivirais/sangue , Doença das Mucosas por Vírus da Diarreia Viral Bovina/imunologia , Doença das Mucosas por Vírus da Diarreia Viral Bovina/prevenção & controle , Bovinos/sangue , Bovinos/virologia , Hidrocortisona/sangue , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Imunização Secundária , Hospedeiro Imunocomprometido/efeitos dos fármacos , Hospedeiro Imunocomprometido/imunologia , Masculino , Meloxicam , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/imunologia , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Tiazinas/sangue , Tiazóis/sangue , Meios de Transporte , Vacinas Atenuadas/administração & dosagemRESUMO
Diving narcosis results from the complex interaction of gases, activities, and environmental conditions. We hypothesized that these interactions could be separated into their component parts. Where previous studies have tested single cognitive tasks sequentially, we varied inspired partial pressures of CO2, N2, and O2 in immersed, exercising subjects while assessing multitasking performance with the Multi-Attribute Task Battery II (MATB-II) flight simulator. Cognitive performance was tested under 20 conditions of gas partial pressure and exercise in 42 male subjects meeting U.S. Navy age and fitness profiles. Inspired nitrogen (N2) and oxygen (O2) partial pressures were 0, 4.5, and 5.6 ATA and 0.21, 1.0, and 1.22 ATA, respectively, at rest and during 100-W immersed exercise with and without 0.075-ATA CO2 Linear regression modeled the association of gas partial pressure with task performance while controlling for exercise, hypercapnic ventilatory response, dive training, video game frequency, and age. Subjects served as their own controls. Impairment of memory, attention, and planning, but not motor tasks, was associated with N2 partial pressures >4.5 ATA. Sea level O2 at 0.925 ATA partially rescued motor and memory reaction time impaired by 0.075-ATA CO2; however, at hyperbaric pressures an unexpectedly strong interaction between CO2, N2, and exercise caused incapacitating narcosis with amnesia, which was augmented by O2 Perception of narcosis was not correlated with actual scores. The relative contributions of factors associated with diving narcosis will be useful to predict the effects of gas mixtures and exercise conditions on the cognitive performance of divers. The O2 effects are consistent with O2 narcosis or enhanced O2 toxicity.
Assuntos
Dióxido de Carbono/sangue , Mergulho/efeitos adversos , Oxigenoterapia Hiperbárica/efeitos adversos , Narcose por Gás Inerte/fisiopatologia , Óxido Nítrico/sangue , Oxigênio/metabolismo , Desempenho Psicomotor , Adulto , Pressão Atmosférica , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/fisiopatologia , Humanos , Narcose por Gás Inerte/etiologia , Masculino , Pessoa de Meia-Idade , Movimento , Adulto JovemRESUMO
This study characterized physiological responses to repeated transportation (TRANS) of gestating cows of differing temperaments. Cows were classified as Calm (C; = 10), Intermediate (I; = 28), or Temperamental (T; = 10). Based on artificial insemination date and pregnancy confirmation, cows were TRANS for 2 h on d 60 (TRANS1), 80 (TRANS2), 100 (TRANS3), 120 (TRANS4), and 140 (TRANS5) ± 5 d of gestation. Indwelling vaginal temperature (VT) monitoring devices were inserted 24 h before each TRANS with VT recorded from 2 h before TRANS and averaged into 5-min intervals through 30 min after TRANS. Serum samples were collected before loading and on unloading from the trailer to determine concentrations of cortisol, glucose, and nonesterified fatty acids (NEFA). Data were analyzed by repeated measures analysis in SAS. Serum cortisol concentrations were affected by temperament ( < 0.001), with T cows having the greater concentrations of cortisol before each TRANS event. All cows (100%) regardless of temperament exhibited elevations in cortisol following each TRANS event. Peak VT was greater ( < 0.001) at TRANS1 relative to all other TRANS events regardless of cow temperament. During TRANS, the T cows tended ( < 0.09) to have greater peak VT (39.86 ± 0.15°C) compared to C (39.41 ± 0.16°C) and I cows (39.55 ± 0.08°C). Area under the VT curve decreased ( = 0.002) from TRANS1 through TRANS5. Pre-TRANS serum glucose concentration at TRANS1 was greater ( < 0.03) for T (68.13 ± 4.31mg/dL) compared to I (53.42 ± 2.78 mg/dL) and C cows (52.76 ± 4.60 mg/dL). The C and I cows had greater changes in NEFA concentration between pre- and post-transport, and T cows showed the least change ( < 0.001). Cow VT and serum glucose concentration decreased in all temperaments ( < 0.01) with repeated TRANS; however, serum NEFA concentration post-TRANS did not vary ( > 0.10) with repeated TRANS events. Serum glucose concentrations were affected ( < 0.02) by a TRANS event by temperament interaction with T cows taking more TRANS events to decrease their change in glucose concentration compared to C and I cows. These results demonstrate that temperament influences physiological responses to stress in gestating Brahman cows. Although repeated transport in our study is confounded with day of gestation, seasonal changes, and learning from repeated handling and transport, repeated transport is a useful model of repeated stress in studying the effects of temperament.
Assuntos
Bovinos/fisiologia , Bovinos/psicologia , Metabolismo Energético/fisiologia , Prenhez/fisiologia , Prenhez/psicologia , Meios de Transporte , Animais , Comportamento Animal/fisiologia , Glicemia/metabolismo , Temperatura Corporal/fisiologia , Ácidos Graxos não Esterificados/sangue , Feminino , Desenvolvimento Fetal/fisiologia , Hidrocortisona/sangue , Gravidez , Estresse Psicológico/psicologia , Temperamento/fisiologia , Fatores de TempoRESUMO
Cancer of the eye in cattle with white faces occurs less frequently in cattle with pigmented eyelids. Corneoscleral pigmentation is related to eyelid pigmentation and occurrence of lesions that may precede cancer. Objectives of this study were to assess 1) variation in the proportion of eyelid and corneoscleral pigmentation in Hereford, Bos taurus, and Bos indicus crossbreds and 2) the occurrence of lesions with the presence of pigmentation in those areas. Hereford and Bos indicus crosses (Brahman or Nellore with Angus and Hereford and straightbred Brafords) and Bos taurus crosses (Angus-Hereford) were included in the study (n = 1,083). Eyelid pigmentation proportions were estimated by pixel quantification and were evaluated as total proportions and for upper and lower eyelids distinctly for each eye. Fixed effects included breed type, age categories, and sex of the animal. Lesion presence (1) or absence (0) was obtained by visual appraisal of image and was assumed to be binomially distributed. Eyelid pigmentation proportions (overall, upper, and lower eyelids) for Hereford ranged from 0.65 ± 0.03 to 0.68 ± 0.03 and were significantly lower than Bos indicus (range from 0.93 ± 0.02 to 0.95 ± 0.02) or Bos taurus (ranged from 0.88 ± 0.02 to 0.92 ± 0.02) crosses. Corneoscleral pigmentation in Hereford cows (0.17 ± 0.06) did not differ (P = 0.91) from Hereford calves and yearlings (0.16 ± 0.07). Bos indicus and Bos taurus crossbred cows had larger corneoscleral pigmentation (0.38 ± 0.05 and 0.48 ± 0.04 for left eyes and 0.37 ± 0.05 and 0.53 ± 0.04 for right eyes, respectively) than all calves (P < 0.001), and their corneoscleral pigmentations were greater than that of Hereford cows (P < 0.003). Bos indicus and Bos taurus cows had greater proportions of left eye corneoscleral pigmentation (0.38 ± 0.05 and 0.48 ± 0.04, respectively) than Hereford cows (0.17 ± 0.06) and all young animal breed types (P < 0.05). Right eye proportions differed for all cow groups (P < 0.05; 0.53 ± 0.04, 0.37 ± 0.05, and 0.17 ± 0.06). Among calves and yearlings, Hereford had a lower right eye corneoscleral pigmentation proportion (0.16 ± 0.07) than Bos taurus (P = 0.02). The lesion proportion for Hereford (0.08 ± 0.03) was significantly greater than that of either Bos indicus (0.01 ± 0.005) or Bos taurus (0.01 ± 0.003). Crossbreeding with Bos taurus or Bos indicus animals appears to increase eye pigmentation, which may help reduce the occurrence of cancer in eyes of cattle with white faces.