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181.
Arnaud Grüss James T. Thorson Gemma Carroll Elizabeth L. Ng Kirstin K. Holsman Kerim Aydin Stan Kotwicki Hem N. Morzaria‐Luna Cameron H. Ainsworth Kevin A. Thompson 《Fish and Fisheries》2020,21(4):718-739
Accounting for variation in prey mortality and predator metabolic potential arising from spatial variation in consumption is an important task in ecology and resource management. However, there is no statistical method for processing stomach content data that accounts for fine‐scale spatio‐temporal structure while expanding individual stomach samples to population‐level estimates of predation. Therefore, we developed an approach that fits a spatio‐temporal model to both prey‐biomass‐per‐predator‐biomass data (i.e. the ratio of prey biomass in stomachs to predator weight) and predator biomass survey data, to predict “predator‐expanded‐stomach‐contents” (PESCs). PESC estimates can be used to visualize either the annual landscape of PESCs (spatio‐temporal variation), or can be aggregated across space to calculate annual variation in diet proportions (variation among prey items and among years). We demonstrated our approach in two contrasting scenarios: a data‐rich situation involving eastern Bering Sea (EBS) large‐size walleye pollock (Gadus chalcogrammus, Gadidae) for 1992–2015; and a data‐limited situation involving West Florida Shelf red grouper (Epinephelus morio, Epinephelidae) for 2011–2015. Large walleye pollock PESC was predicted to be higher in very warm years on the Middle Shelf of the EBS, where food is abundant. Red grouper PESC was variable in north‐western Florida waters, presumably due to spatio‐temporal variation in harmful algal bloom severity. Our approach can be employed to parameterize or validate diverse ecosystem models, and can serve to address many fundamental ecological questions, such as providing an improved understanding of how climate‐driven changes in spatial overlap between predator and prey distributions might influence predation pressure. 相似文献
182.
以东北农业大学西甜瓜育种研究室自育的西瓜品系"W1-17"为材料,以EMS为诱变剂,采用5个EMS诱变浓度(0.2%、0.6%、1.0%、1.4%和1.8%),4个处理时间(3、6、9和12 h),分析诱变后种子发芽率、相对出苗率和相对成苗率情况,最终确定EMS处理浓度1.0%、诱导时间9 h为西瓜品系"W1-17"种子最佳诱变条件。 相似文献
183.
Summary
Bradyrhizobium japonicum strain G49 has been the only inoculum used in French soils. Soybean (Glycine max L. Merr.) cultivars were selected and tested according to their performances with this rhizobial strain. The aim of the present study was to determine the consequences of strain substitution on N2 fixation abilities of various genotypes. Three genotypes and cultivar Weber, in combination with B. japonicum strain G49 or SMGS1, were cultivated in pots and tested for nitrogenase activity under differing nitrogen nutrition conditions. The reliability of ARA (acetylene reduction activity) measurement for assessing symbiotic nitrogen fixation under the experimental conditions used was checked. Genotypic variability for symbiotic fixation activity was observed with each strain under soil culture conditions; important genotype x strain interactions were also involved. These results were corroborated for the protein yield and other yield component performances of the various genotype-strain associations. Thus, in France, the replacement of strain G49 with another one might result in the alteration of the relative agronomic performances of the soybean cultivars, since N2 fixation is considered as a major factor of soybean productivity. 相似文献
184.
F J Neto F Massone S P Luna A A Camacho J R Júnior H M Ishiy 《Canadian journal of veterinary research》2001,65(2):116-124
The effects of atropine and methotrimeprazine on epinephrine-induced ventricular arrhythmias were evaluated in halothane-anesthetized dogs. Ten mixed-breed dogs were assigned to 3 treatments (saline, atropine, and methotrimeprazine) in a randomized complete block design. Anesthesia was induced and maintained with halothane (1.5 minimum alveolar concentration) in oxygen. Controlled ventilation was used throughout to maintain eucapnia. Saline, atropine (0.05 mg/kg, i.v.) or methotrimeprazine (0.5 mg/kg, i.v.) were administered and, 5 minutes later the arrhythmogenic dose of epinephrine (ADE) was measured by i.v. infusion of progressively increasing infusion rates of epinephrine, until the ventricular arrhythmia criterion was met (at least 4 ectopic ventricular contractions (EVCs) during a 15-second period). Data were analyzed using a student's t-test for ADE values and multivariate profile analysis for heart rate (HR), arterial blood pressure (ABP), and rate pressure product (RPP). The ADE increased in atropine- and methotrimeprazine-treated groups, whereas 1 and 4 animals from these groups did not develop any ventricular arrhythmia, respectively. Epinephrine induced multiform premature ventricular contractions (PVCs) in the atropine group, whereas ventricular escape beats were observed in the control and methotrimeprazine groups. Heart rate and RPP decreased, and ABP increased at the time of ADE observation in the control group. Epinephrine infusion in the atropine group caused marked increases in HR, ABP, and RPP, which were associated with pulsus alternans in 2 animals. It was concluded that 1) the presence of cholinergic blockade influences the type of ventricular arrhythmia induced by epinephrine; 2) increased ADE values recorded following atropine administration must be cautiously interpreted, since in this situation the PVCs were associated with signs of increased myocardial work and ventricular failure; and 3) the use of a broader arrhythmia criterion (EVCs instead of PVCs) may not allow a direct comparison between ADE values, since it includes ventricular arrhythmias mediated by different mechanisms. 相似文献
185.
Electroacupuncture analgesia in dogs: is there a difference between uni- and bi-lateral stimulation?
OBJECTIVE: To compare the analgesic effect of uni- and bi-lateral electroacupuncture (EA) in response to thermal and mechanical nociceptive stimuli and to investigate the cardiorespiratory, endocrine, and behavioral changes in dogs submitted to EA. STUDY DESIGN: Prospective, randomized cross-over experimental study. ANIMALS: Eight adult, clinically healthy, cross-breed dogs, weighing 13 +/- 4 kg. METHODS: Dogs underwent electrostimulation at false acupoints (T-false); bilateral EA at acupoints, stomach 36, gall bladder 34 and spleen 6 (T-EA/bil); unilateral EA at the same points (T-EA/uni) or were untreated (T-control). All animals received acepromazine (0.05 mg kg(-1)) IV; and heart rate, pulse oximetry, indirect arterial blood pressure, respiratory rate, Pe'CO(2), rectal temperature, and plasma cortisol concentration were measured before, during, and after EA. Analgesia was tested using thoracic and abdominal cutaneous thermal and mechanical stimuli, and an interdigital thermal stimulus. Behavior was classified as calm or restless. Analysis of variance for repeated measures followed by Tukey's test was used for analysis of the data. RESULTS: There were no cardiorespiratory differences among the treatments. The cutaneous pain threshold was higher after EA, compared with false points. The latency period was shorter and analgesia was more intense in T-EA/bil than T-EA/uni, when both were compared with T-false and T-control. Six out of eight animals treated with EA were calm during treatment, and 5/8 and 4/8 of the T-false and T-control animals, respectively, were restless. Latency to interdigital thermal stimulation increased in T-EA/bil compared with the others. There was no difference in plasma cortisol concentrations among the treatments. CONCLUSIONS: Bilateral EA produced a shorter latency period, a greater intensity, and longer duration of analgesia than unilateral stimulation, without stimulating a stress response. CLINICAL RELEVANCE: Bilateral EA produces a better analgesic effect than unilateral EA. 相似文献
186.
Miguel Gozalo‐Marcilla Rodrigo Moreira da Silva Stelio Pacca Loureiro Luna Alice Rodrigues de Oliveira Mariana Werneck Fonseca Norberto Peporine Lopes Polly M. Taylor Ludovic Pelligand 《Journal of veterinary pharmacology and therapeutics》2019,42(6):738-744
The alpha(α)2‐agonist detomidine is used for equine sedation with opioids such as methadone. We retrieved the data from two randomized, crossover studies where detomidine and methadone were given intravenously alone or combined as boli (STUDY 1) (Gozalo‐Marcilla et al., 2017, Veterinary Anaesthesia and Analgesia, 2017, 44 , 1116) or as 2‐hr constant rate infusions (STUDY 2) (Gozalo‐Marcilla et al., 2019, Equine Veterinary Journal, 51 , 530). Plasma drug concentrations were measured with a validated tandem Mass Spectrometry assay. We used nonlinear mixed effect modelling and took pharmacokinetic (PK) data from both studies to fit simultaneously both drugs and explore their nonlinear kinetics. Two significant improvements over the classical mammillary two‐compartment model were identified. First, the inclusion of an effect of detomidine plasma concentration on the elimination clearances (Cls) of both drugs improved the fit of detomidine (Objective Function Value [OFV]: ?160) and methadone (OFV: ?132) submodels. Second, a detomidine concentration‐dependent reduction of distributional Cls of each drug further improved detomidine (OFV: ?60) and methadone (OFV: ?52) submodel fits. Using the PK data from both studies (a) helped exploring hypotheses on the nonlinearity of the elimination and distributional Cls and (b) allowed inclusion of dynamic effects of detomidine plasma concentration in the model which are compatible with the pharmacology of detomidine (vasoconstriction and reduction in cardiac output). 相似文献
187.
Emily G. Pieracci Juan Diego Perez De La Rosa Daniel Luna Rubio Mario Eduardo Solis Perales Manuel Velasco Contreras Naomi A. Drexler William L. Nicholson Jos Javier Prez De La Rosa Ida H. Chung Cecilia Kato Casey Barton Behravesh María Alejandra Gay Enríquez Jesús Felipe Gonzlez Roldan Margarita E. Villarino 《Zoonoses and public health》2019,66(8):918-926
Portions of northern Mexico are experiencing a re‐emergence of Rocky Mountain spotted fever (RMSF), a tickborne disease caused by Rickettsia rickettsii, a member of the spotted fever group of rickettsiae (SFGR). Infection with R. rickettsii can result in serious and life‐threatening illness in people and dogs. Canine seroprevalence has been used as a sentinel for human RMSF in previous studies. This study aims to quantify SFGR seroprevalence in canines in three northern Mexican states and identify risk factors associated with seropositivity. A total of 1,136 serum samples and 942 ticks were obtained from dogs participating in government sterilization campaigns and from animal control facilities in 14 Mexican cities in three states. SFGR antibodies were detected using indirect immunofluorescence antibody assays at titre values ≥1/64. Six per cent (69 dogs) showed antibodies to SFGR, with the highest seroprevalence reported in Baja California (12%), Coahuila (4%) and Sonora (4%). Dogs from Baja California had three times higher odds of having SFGR antibodies compared to dogs from Sonora (OR = 3.38, 95% CI, 1.81–6.37). Roughly one quarter (25%) of surveyed dogs were parasitized by ticks (Rhipicephalus sanguineus sensu lato) at the time of sample collection. A portion of collected ticks were tested for rickettsial DNA using polymerase chain reaction. Positive samples were then sequenced, showing evidence of SFGR including R. massiliae, R. parkeri and R. rickettsii. Dogs that spent the majority of time on the street, such as free‐roaming or community‐owned dogs, showed a greater risk of tick infestation, seropositivity, bearing seropositive ticks, and may play a pivotal role in the spread of SFGR among communities. Estimating the seroprevalence of SFGR in the canine population can help public health campaigns target high‐risk communities for interventions to reduce human RMSF cases. 相似文献
188.
Reproductive performance of seasonally anovular mixed‐bred dairy goats induced to ovulate with a combination of progesterone and eCG or estradiol
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Viridiana Contreras‐Villarreal César A. Meza‐Herrera Raymundo Rivas‐Muñoz Oscar Angel‐Garcia Juan R. Luna‐Orozco Evaristo Carrillo Miguel Mellado Francisco G. Véliz‐Deras 《Animal Science Journal》2016,87(6):750-755
Adult goats (n = 32) were randomly assigned to one of four treatments (n = 8, each): (i) progesterone (P4) + equine chorionic gonadotropin (eCG), treated with 25 mg progesterone intramuscularly (i.m.) + 250 IU eCG 24 h later; (ii) cronolone + eCG, treated with vaginal sponges ‐ 20 mg cronolone × 7 days + 250 IU eCG at pessary removal; (ii) P4 + estradiol (E2), treated with 25 mg progesterone i.m. + 1 mg estradiol 24 h later; (iv) cronolone + E2, treated with vaginal sponges ‐ 20 mg cronolone × 7 days + 1 mg of estradiol i.m. at pessary removal. Goats were tested for estrus throughout the presence of a buck. Seven days prior and after treatment, an ovarian ultrasonographic scanning was performed to determine ovarian function and structures. An ultrasonographic pregnancy diagnosis was performed on day 30 post‐service. In all groups, 100% estrus response was observed within 96 h post‐treatment. While ovulation occurred in 100% of P4 + eCG and cronolone + eCG treated goats, the other groups only depicted 50% ovulatory activity (P < 0.05). Pregnancy rate was higher (P <0.05) in the P4 + eCG and cronolone + eCG groups (88 and 100%, respectively), compared with 38% in P4 + E2 and cronolone + E2 groups. The best treatments were those in which eCG was applied. The P4 + eCG treatment was a pessary‐free, cheaper and effective protocol to induce ovulation in goats during the seasonal anovulatory period. 相似文献
189.
Carregaro AB Luna SP Mataqueiro MI de Queiroz-Neto A 《American journal of veterinary research》2007,68(3):246-250
OBJECTIVE: To investigate spontaneous locomotor activity (SLA) and antinociceptive effects of buprenorphine in horses. ANIMALS: 6 healthy adult horses. PROCEDURES: Horses received each of 3 treatments (10 mL of saline [0.9% NaCl] solution, 5 microg of buprenorphine/kg, or 10 microg of buprenorphine/kg).Treatments were administered IV. Order of treatments was randomized, and there was a 10-day interval between subsequent treatments. Spontaneous locomotor activity was investigated in a behavioral box by use of infrared photoelectric sensors connected to a computer, which detected movement of each horse. Antinociceptive effect was investigated by hoof-withdrawal reflex latency (HWRL) and skin-twitching reflex latency (STRL) after painful stimulation with a heat lamp. RESULTS: Moderate excitement was observed in all horses from 5 to 10 minutes after the administration of both dosages of buprenorphine. The SLA increased significantly for 6 and 14 hours after IV administration of 5 and 10 microg of buprenorphine/kg, respectively. Values for HWRL increased significantly only at 30 minutes after injection of 5 microg of buprenorphine/kg, whereas STRL and HWRL each increased significantly from 1 to 6 hours (except at 2 and 4 hours) and 11 hours, respectively, after injection of 10 microg of buprenorphine/kg. CONCLUSIONS AND CLINICAL RELEVANCE: IV injection of buprenorphine caused a dose-dependent increase in SLA, but only the dose of 10 microg/kg induced analgesia on the basis of results for the experimental method used. 相似文献