State-dependent learned valuation drives choice in an invertebrate

Humans and other vertebrates occasionally show a preference for items remembered to be costly or experienced when the subject was in a poor condition (this is known as a sunk-costs fallacy or state-dependent valuation). Whether these mechanisms shared across vertebrates are the result of convergence toward an adaptive solution or evolutionary relicts reflecting common ancestral traits is unknown. Here we show that state-dependent valuation also occurs in an invertebrate, the desert locust Schistocerca gregaria (Orthoptera: Acrididae). Given the latter's phylogenetic and neurobiological distance from those groups in which the phenomenon was already known, we suggest that state-dependent valuation mechanisms are probably ecologically rational solutions to widespread problems of choice.     

Anaplasma marginale: lack of cross-protection between strains that share MSP1a variable region and MSP4

In Mexico, there are no commercial alternatives for the immunoprophylaxis of bovine Anaplasmosis, a disease responsible for great economic losses. Blood derived Anaplasma marginale used for immunizing susceptible cattle has shown promising results for homologous protection and controversial results against unrelated strains. The present study examined, under controlled conditions, the cross-protective potential of an immunogen composed of blood derived A. marginale of three strains against challenge with strains not included in the immunogens. Groups 1 and 2 were immunized with blood derived Anaplasma from strains Mexico, Morelos and Yucatan, group 4 with strains Morelos, Veracruz and Yucatan, two more groups (2 and 5) of equal conditions were inoculated with an adjuvant alone. Groups 1, 4 and 5 were challenged with Mexico strain; groups 2 and 3 were challenge-inoculated with strain Veracruz; groups 3 and 5 with strains Veracruz and Mexico as controls. Only animals in group 1, immunized and challenged with strain Mexico showed adequate protection. Both groups challenged with strains not included in the immunogens developed poor protection, while all the controls had to be treated to prevent death.     

Mouse epidermal development: effects of retinoic acid exposure in utero

Epidermal morphogenesis was studied in vivo following prenatal exposure to retinoic acid (RA). In pregnant mice, a single oral dose of RA on day 11.5 of gestation failed to induce histological changes in fetal epidermal development except in epidermal thickness. Epidermal thickness increased from 16.5 days post-coitum (dpc) onwards, and temporal and spatial epidermal modifications in keratins K5 and K14 related to proliferative activity of keratinocytes were observed. An RA effect on cell proliferation was supported by a statistically significant increase in the number of epidermal S-phase cells, containing BrdU-incorporated DNA in RA-exposed mice compared with nonexposed animals. The prolonged in utero action of RA on epidermal proliferative activity in fetuses and newborns suggests a long-term RA effect that may play a role on the development and evolution of diseases in adult skin.     

Surgical management of a malacic corneal ulcer in a greater one-horned Asian rhinoceros (Rhinoceros unicornis) using a free island tarsoconjunctival graft

A greater one-horned Asian rhinoceros (Rhinoceros unicornis) presented for presumed ocular trauma to the left eye, with secondary bacterial infection, resulting in severe and progressive corneal ulceration. Following a poor response to medical therapy, the animal was anesthetized for further examination, and a bulbar conjunctival pedicle graft performed. This graft failed by 48-h postsurgery as a result of self-trauma. The animal was re-anesthetized, and a free island tarsoconjunctival graft performed. This second procedure was successful, resulting in globe preservation, cosmesis, and functional vision in the affected eye.     

Prevalence of mange among West African Dwarf sheep and goats and associated haematological and biochemical parameters

This study was carried out to assess the prevalence of mange in sheep and goats in five local government areas (LGAs) of Ogun State in South Western Nigeria. A total of 4,973 sheep and 7,902 goats of West African Dwarf breeds were sampled of which only 4 (0.08%) of sheep and 42 (0.53%) of goats were confirmed positive for mange infestation. In all the LGAs sampled, Odeda LGA had the highest concentration of sheep (39%) and goats (51%) while Abeokuta South had the least percentage of sheep (1%) and goats (1%). All the mange-infested cases in sheep were recorded in just one LGA (Ewekoro) which constituted 0.24% of the population within the location. For goats, three out of five LGAs namely: Obafemi Owode, Ewekoro and Abeokuta North had prevalence of 1.46%, 0.53% and 0.72% respectively. There was no significant (P > 0.05) difference between non-infested and infested animals in terms of packed cell volume (31.79 ± 0.87% vs. 31.41 ± 1.13%), haemoglobin (10.51 ± 0.21 g/100 ml vs. 10.28 ± 0.37 g/100 ml) and red blood cells (8.71 ± 0.29 × 10(12)/l vs. 9.40 ± 0.37 × 10(12)/l). The infested group however showed significantly (P < 0.01) higher white blood cells count (7.60 ± 0.22 × 10(9)/l) than the non-infested animals (6.81 ± 0.17 × 10(9)/l). Neutrophil, eosinophil, basophil and monocyte as well as chloride were not significantly affected by the health status of the animals. There existed significant (P < 0.01) difference between non-infested and infested animals in terms of total protein (5.42 ± 0.16 vs. 4.75 ± 0.20 g/dl), sodium (137.98 ± 1.53 vs. 128.92 ± 1.92 mEq/l) and potassium (4.04 ± 0.14 vs. 3.46 ± 0.18 mEq/l). It can be concluded from this study that the prevalence of mange mite infestation varied with location and was generally low or absent in some of the LGAs considered. Goats were particularly more susceptible to mange infestation than sheep. More concerted effort is needed to control mange in order to avoid spread since it is a contagious disease.     

Predictors of differences in the perception of antimicrobial resistance risk in the treatment of sick, at-risk, and high-risk feedlot cattle

Concerns exist that some uses of antimicrobials in cattle may lead to the emergence, proliferation, dissemination and persistence of resistant pathogenic bacteria in animal agriculture, which in turn can infect humans via the food supply. The degree of perceived risk varies with the clinical indication for which the antimicrobial in question is used. In this study, four uses of antimicrobials are considered, including in acutely sick, chronically sick, at-risk, and high-risk cattle, contrasting the degree of risk among these uses. Using a random sample of 103 feedlot cattle veterinarians and variables drawn from the theory of planned behavior, we predict differences in risk perception by clinical indication with differences in perceived efficacy of antimicrobials, social pressures to use antimicrobials, and moral obligations to use antimicrobials. In most models, veterinarians who perceived that others in the feedlot industry (i.e., other feedlot veterinarians, nutritionists, feedlot clients, and retained owners of cattle) were more likely to expect them to use antimicrobials in one situation versus another, the less likely those veterinarians perceived the risk of antimicrobial risk to be greater in the former versus the latter situation. Only two of these contrasts contained influences outside the immediate feedlot relationships. This exception involves the 'downstream' public: meat packers, retailers, and consumers. Veterinarians who believe that using antimicrobials for acutely sick cattle is more beneficial than using antimicrobials for chronically sick cattle were more likely to believe that antimicrobial resistance was a less probable outcome in acutely sick cattle than in chronically sick cattle.     

Evaluation of a multi-line broiler chicken population using a single-step genomic evaluation procedure

Effects on prediction of analysing a multi-line chicken population as one line were evaluated. Body weight records were provided by Cobb-Vantress for two lines of broiler chickens. Phenotypic records for 183 695 and 164 149 broilers and genotypic records for 3195 and 3001 broilers were available for each line. Lines were combined to create a multi-line population and analysed using a single-step procedure combining the additive relationship matrix and the genomic relationship matrix (G). G was scaled using allele frequencies from each line, the multi-line population, or 0.5. When allele frequencies were calculated from each line, distributions of diagonal elements were bimodal. When allele frequencies were calculated from the multi-line population, the distribution of diagonal elements had one peak. When allele frequency 0.5 was used, the distribution was bimodal. Genomic estimated breeding values (GEBVs) were predicted using each allele frequency. GEBVs differed with allele frequency but had ≥ 0.99 correlations with GEBVs predicted with correct allele frequencies. Means of each line and differences in mean between the lines differed based on allele frequencies. Assumed allele frequencies have little impact on ranking within line but larger impact on ranking across lines. G may be used to evaluate multiple populations simultaneously but must be adjusted to obtain properly scaled estimates when population structure is unknown.