Effects of X-rays on Tuta absoluta for use in inherited sterility programmes

Tuta absoluta is a key pest of tomato crops originating from South America. The consequences of X-radiation on this species were studied under laboratory controlled conditions. The effect of radiation on adult emergence was evaluated exposing male and female pupae to increasing X-rays. Adult emergence decreased as doses of X-radiation increased, with the appearance of deformities such as malformed wings and bent legs at doses ≥350?Gy. Besides, males and females obtained from irradiated pupae were out crossed with untreated counterparts to explore the effects of X-radiation on inherited sterility. (a) Irradiated male?×?untreated female crosses. Both fecundity and fertility of the untreated females were reduced by radiation, and the effect was stronger as the doses increased. Neither the longevity of parental males and F1 adults nor the sex ratios of the F1 and F2 generations were affected by X-radiation (F1 and F2: first and second generation of descendants of irradiated adults). Inherited sterility effects were manifested by a significant reduction in the F1 fecundity, F1 fertility, and the amount of larvae and pupae produced. Doses of 200–250?Gy could be used to induce inherited sterility in T. absoluta males. (b) Untreated male?×?irradiated female crosses. The minimum dose at which irradiated females were completely sterile was 200?Gy. The present study is the first study in T. absoluta that provides the starting point for implementing the inherited sterility in this species.     

Evaluation of Nociception,Sedation, and Cardiorespiratory Effects of a Constant Rate Infusion of Xylazine Alone or in Combination with Lidocaine in Horses

This study aimed to evaluate the effects of a constant rate infusion (CRI) of xylazine or xylazine in combination with lidocaine on nociception, sedation, and physiologic values in horses. Six horses were given intravenous (IV) administration of a loading dose (LD) of 0.55 mg/kg of xylazine followed by a CRI of 1.1 mg/kg/hr. The horses were randomly assigned to receive three treatments, on different occasions, administered 10 minutes after initiation of the xylazine CRI, as follows: control, physiologic saline; lidocaine low CRI (LLCRI), lidocaine (LD: 1.3 mg/kg, CRI: 0.025 mg/kg/min); and lidocaine high CRI (LHCRI), lidocaine (LD: 1.3 mg/kg, CRI: 0.05 mg/kg/min). A blinded observer assessed objective and subjective data for 50 minutes during the CRIs. In all treatments, heart and respiratory rates decreased, end-tidal carbon dioxide concentration increased, and moderate to intense sedation was observed, but no significant treatment effect was detected in these variables. Ataxia was significantly higher in LHCRI than in the control treatment at 20 minutes of infusion. Compared with baseline values, nociceptive threshold increased to as much as 79% in the control, 190% in LLCRI, and 158% in LHCRI. Nociceptive threshold was significantly higher in LLCRI (at 10 and 50 minutes) and in LHCRI (at 30 minutes) than in the control treatment. The combination of CRIs of lidocaine with xylazine produced greater increases in nociceptive threshold compared with xylazine alone. The effects of xylazine on sedation and cardiorespiratory variables were not enhanced by the coadministration of lidocaine. The potential to increase ataxia may contraindicate the clinical use of LHCRI, in combination with xylazine, in standing horses.     

Minimum infusion rate and hemodynamic effects of propofol, propofol-lidocaine and propofol-lidocaine-ketamine in dogs

ObjectiveTo evaluate the effects of a constant rate infusion (CRI) of lidocaine alone or in combination with ketamine on the minimum infusion rate (MIR) of propofol in dogs and to compare the hemodynamic effects produced by propofol, propofol-lidocaine or propofol-lidocaine-ketamine anesthesia.Study designProspective, randomized cross-over experimental design.AnimalsFourteen adult mixed-breed dogs weighing 15.8 ± 3.5 kg.MethodsEight dogs were anesthetized on different occasions to determine the MIR of propofol alone and propofol in combination with lidocaine (loading dose [LD] 1.5 mg kg^?1, CRI 0.25 mg kg^?1 minute^?1) or lidocaine (LD 1.5 mg kg^?1, CRI 0.25 mg kg^?1 minute^?1) and ketamine (LD 1 mg kg^?1, CRI 0.1 mg kg^?1 minute^?1). In six other dogs, the hemodynamic effects and bispectral index (BIS) were investigated. Each animal received each treatment (propofol, propofol-lidocaine or propofol-lidocaine-ketamine) on the basis of the MIR of propofol determined in the first set of experiments.ResultsMean ± SD MIR of propofol was 0.51 ± 0.08 mg kg^?1 minute^?1. Lidocaine-ketamine significantly decreased the MIR of propofol to 0.31 ± 0.07 mg kg^?1 minute^?1 (37 ± 18% reduction), although lidocaine alone did not (0.42 ± 0.08 mg kg^?1 minute^?1, 18 ± 7% reduction). Hemodynamic effects were similar in all treatments. Compared with the conscious state, in all treatments, heart rate, cardiac index, mean arterial blood pressure, stroke index and oxygen delivery index decreased significantly, whereas systemic vascular resistance index increased. Stroke index was lower in dogs treated with propofol-lidocaine-ketamine at 30 minutes compared with propofol alone. The BIS was lower during anesthesia with propofol-lidocaine-ketamine compared to propofol alone.Conclusions and clinical relevanceLidocaine-ketamine, but not lidocaine alone, reduced the MIR of propofol in dogs. Neither lidocaine nor lidocaine in combination with ketamine attenuated cardiovascular depression produced by a continuous rate infusion of propofol.     

Comparing Dung Beetle Species Assemblages Between Protected Areas and Adjacent Pasturelands in a Mediterranean Savanna Landscape

Dung beetles are considered keystone species because of their role in decomposition, seed dispersal, and control of vertebrate parasites in grazed habitats. Despite the ecological importance of this group to pasture ecosystem functioning, still little is known about its relationship with grazing management activities. We evaluated the conservation value of protected areas for dung beetle diversity by comparing two different management conditions of Mediterranean savanna in central Spain. Four different sites with wild herbivory (red deer, roe deer) were sampled inside the Cabañeros National Park, and four sites with traditional agrosilvopastoral management were sampled in a sheep farm near the park. The dung beetle species richness was similar between savanna conditions, but the total dung beetle abundance and biomass were considerably greater in the park grasslands than in the grasslands of the sheep farm. Dung beetle species composition, species dominance, and abundance by functional groups from both park and farm sites were different, despite the high similarity among the sampled sites in both hydric content and dung availability. Onthophagus maki (Illiger 1803) and O. furcatus (Fabricius 1781) were the dominant species in the park, while O. furcatus, Aphodius foetidus (Herbst 1783), and Caccobius schreberi L. were the dominant species on the farm. Species richness and abundance of telecoprids were higher in the park than on the farm. Abundance of paracoprids was also higher in the park than on the farm, while no differences in species richness and abundance of endocoprids were observed between both conditions. These results suggest that management activities such as plowing and the use of veterinary substances affect soil structure and dung quality and could be important factors that alter dung beetle assemblages in terms of composition, abundance, and biomass on traditional farms.     

Bayesian inference for multi-environment spatial individual-tree models with additive and full-sib family genetic effects for large forest genetic trials

Context

The gain in accuracy of breeding values with the use of single trial spatial analysis is well known in forestry. However, spatial analyses methodology for single forest genetic trials must be adapted for use with combined analyses of forest genetic trials across sites.

Aims

This paper extends a methodology for spatial analysis of single forest genetic trial to a multi-environment trial (MET) setting.

Methods

A two-stage spatial MET approach using an individual-tree model with additive and full-sib family genetic effects was developed. Dispersion parameters were estimated using Bayesian techniques via Gibbs sampling. The procedure is illustrated using height growth data at age 10 from eight large Tsuga heterophylla (Raf.) Sarg. second-generation full-sib progeny trials from two series established across seven sites in British Columbia (Canada) and on one in Washington (USA).

Results

The proposed multi-environment spatial mixed model displayed a consistent reduction of the posterior mean and an increase in the precision of error variances $ \left( {\sigma _{e}^{2}} \right) $ than the model with ??sets in replicates?? or incomplete block alpha designs. Also, the multi-environment spatial model provided an average increase in the posterior means of the narrow- and broad-sense individual-tree heritabilities (h _N ² and h _B ² , respectively). No consistent changes were observed in the posterior means of additive genetic correlations (r _Ajj??).

Conclusion

Although computationally demanding, all dispersion parameters were successfully estimated from the proposed multi-environment spatial individual-tree model using Bayesian techniques via Gibbs sampling. The proposed two-stage spatial MET approach produced better results than the commonly used nonspatial MET analysis.     

Acclimatation of three co-occurring tree species to water stress and their role as site indicators in mixed pine-oak forests in the Sierra Madre Oriental,Mexico

Water availability and salt excess are limiting factors in Mexican mixed pine-oak forest. In order to characterise the acclimatation of native species to these stresses, leaf water (Ψ_w) and osmotic potentials (Ψ_s) of Juniperus flaccida, Pinus pseudostrobus and Quercus canbyi were measured under natural drought and non-drought conditions under two different aspects in the Sierra Madre Oriental. Factorial ANOVA revealed significant differences in Ψ_w and Ψ_s between two aspects, species and sampling dates. In general, all species showed high predawn and low midday values that declined progressively with increasing drought and soil–water loss. Seasonal and diurnal fluctuation of Ψ_w and Ψ_s were higher for J. flaccida and Q. canbyi than for P. pseudostrobus. Leaf Ψ_w and Ψ_s were mainly correlated with soil water content, while Ψ_s of P. pseudostrobus were hardly correlated with environmental variables. Thus, species have different strategies to withstand drought. P. pseudostrobus was identified as a species with isohydric water status regulation, while J. flaccida and Q. canbyi presented water potential patterns typical for anisohydric species. The type of water status regulation may be a critical factor for plant survival and mortality in the context of climate change. Nevertheless, for precise conclusions about the advantages and disadvantages of each type, further long-term investigations are required.     

The impact of feed withdrawal on quality, safety, yield of pocessed chickens

一旦肉鸡达到上市体重并准备送入屠宰厂之时,肉品的加工处理就已经开始了.在这个时候,为了出空肉鸡肠道中的排泄物以防止在切除内脏时所发生的污染而必须采取禁食措施.否则,会影响肉鸡胴体预冷前的质量安全.     

Some Factors Affecting the Rate of Pregnancy after Embryo Transfer Derived from the Brazilian Jumper Horse Breed

This study aimed to evaluate the effects of certain embryo transfer parameters on the pregnancy rate after equine embryo transfer of the Brazilian Jumper Horse breed. The size, embryonic development stage, embryo quality, and synchronization of ovulation between the donor (n = 120) and recipient (n = 420) were evaluated in 396 embryos. Embryo recovery was performed on Day 6-9 after ovulation (Day 0 = day of ovulation). The recipient mares were chosen on the day of embryo recovery, and the transfers were performed that same day. The embryo size (diameter including envelopes; n = 396) ranged from 150 to 3000 μm; 67.1% measured between 400 and 1199 μm. The embryo size (400-1199 μm vs. ≤399 μm); stage of development (n = 396; blastocyst and expanded blastocyst versus compact morula and early blastocyst); quality (n = 396; grade 1 [excellent]), 2 [good], or 3 [poor]); and synchronization of ovulation between the donor and recipient (0, 1, 2, 3, and 4 days versus −1, 5, and 6 days, respectively) all affected pregnancy rate (P < .05). The pregnancy rate did not differ significantly among transfers performed on Days 0, 1, 2, 3, and 4. In conclusion, embryos measuring 400-1199 μm produced higher pregnancy rates in recipients than embryos measuring 150-399 μm, and blastocysts and expanded blastocysts produced pregnancy more efficiently than morulae and early blastocysts. The embryo quality also affected the pregnancy rate. Synchronization of donor and recipient ovulation to Days 0-4 improved the efficiency of embryo transplant.     

Optimal Management Practices for Nitrogen Application in Corn Cultivated During Summer and Fall in the Tropics

Optimal management practices for nitrogen (N) fertilization is well defined for corn (Zea mays) cultivated during summer (“summer” corn), but not for corn cultivated during the fall (“fall” corn) in the tropics. Two experiments were carried out to evaluate N rates (50, 100, 200, and 300 kg N ha^?1), N application timing (pre-planting – PP, V2–V3, and V5–V6) and N split application, once (at PP, V3, and V6), two (at V3+ V6) and three times (at PP+ V3+ V6) in corn cultivated during summer (2014/2015) and fall (2015/2016). Data on corn grain yield (CGY), weight of 1000-grains, leaf N content and values of soil-plant analyses development (SPAD) were collected and analyzed using univariate, multivariate (principal component analysis, PCA) and regression analysis. Results showed that corn growth was affected by N rates and splitting. Corn cultivated during summer presented higher CGY and weight-1000 g than corn cultivated during the fall. The highest yields were obtained with higher N rates on “summer” corn (125 kg N ha^?1) than “fall” corn (50 kg N ha^?1). Split N-application at vegetative growth stages, V3+ V6, or PP+ V2+ V6, provided higher yields for “summer” corn, while only PP application was a reliable period of N fertilization for “fall” corn. The finding is that corn cultivated during the fall presented a lower response to N and no obvious advantages to split N fertilization when compared to corn cultivated during summer. These optimal management practices for N fertilization in corn production in the tropics depend on soil water availability.