Transfer of functions based on equivalence class formation using musical stimuli.

Empirical evidence has supported that musical excerpts written in major and minor modes are responsible for evoking happiness and sadness, respectively. In this study, we evaluated whether the emotional content evoked by musical stimuli would transfer to abstract figures when they became members of the same equivalence class. Participants assigned to the experimental group were submitted to a training procedure to form equivalence classes comprising musical excerpts (A) and meaningless abstract figures (B, C, and D). Afterward, transfer of function was evaluated using a semantic differential. Participants in the control group showed positive semantic differential scores for major mode musical excerpts, negative scores for minor mode musical excerpts, and neutral scores for the B, C, and D stimuli. Participants in the experimental groups showed positive semantic differential scores for visual stimuli equivalent to the major modes and negative semantic differential scores for visual stimuli equivalent to the minor modes. These results indicate transfer of function of emotional content present in musical stimuli through equivalence class formation. These findings could provide a more comprehensive understanding of the effects of using emotional stimuli in equivalence class formation experiments and in transfer of function itself.

SARS-CoV-2 variants, its recombinants and epigenomic exploitation of host defenses.

Since 2003, we have seen the emergence of novel viruses, such as SARS-CoV-1, MERS, ZIKA, swine flu virus H1N1, Marburg, Monkeypox, Ebola, and SARS-CoV-2, but none of them gained pandemic proportions similar to SARS-CoV-2. This could be attributed to unique viral traits, allowing its rapid global dissemination following its emergence in October 2019 in Wuhan, China, which appears to be primarily driven by the emergence of highly transmissible and virulent variants that also associate, in some cases, with severe disease and considerable mortality caused by fatal pneumonia, acute respiratory distress syndrome (ARDS) in infected individuals. Mechanistically, several factors are involved in viral pathogenesis, and epigenetic alterations take the front seat in host-virus interactions. The molecular basis of all viral infections, including SARS-CoV-2, tightly hinges on the transitory silencing of the host gene machinery via epigenetic modulation. SARS-CoV-2 also hijacks and subdues the host gene machinery, leading to epigenetic modulation of the critical host elements responsible for antiviral immunity. Epigenomics is a powerful, unexplored avenue that can provide a profound understanding of virus-host interactions and lead to the development of epigenome-based therapies and vaccines to counter viruses. This review discusses current developments in SARS-CoV-2 variation and its role in epigenetic modulation in infected hosts. This review provides an overview, especially in the context of emerging viral strains, their recombinants, and their possible roles in the epigenetic exploitation of host defense and viral pathogenesis. It provides insights into host-virus interactions at the molecular, genomic, and immunological levels and sheds light on the future of epigenomics-based therapies for SARS-CoV-2 infection.

Understanding the genetic complexity of puberty timing across the allele frequency spectrum.

Pubertal timing varies considerably and has been associated with a range of health outcomes in later life. To elucidate the underlying biological mechanisms, we performed multi-ancestry genetic analyses in ~800,000 women, identifying 1,080 independent signals associated with age at menarche. Collectively these loci explained 11% of the trait variance in an independent sample, with women at the top and bottom 1% of polygenic risk exhibiting a ~11 and ~14-fold higher risk of delayed and precocious pubertal development, respectively. These common variant analyses were supported by exome sequence analysis of ~220,000 women, identifying several genes, including rare loss of function variants in ZNF483 which abolished the impact of polygenic risk. Next, we implicated 660 genes in pubertal development using a combination of in silico variant-to-gene mapping approaches and integration with dynamic gene expression data from mouse embryonic GnRH neurons. This included an uncharacterized G-protein coupled receptor GPR83, which we demonstrate amplifies signaling of MC3R, a key sensor of nutritional status. Finally, we identified several genes, including ovary-expressed genes involved in DNA damage response that co-localize with signals associated with menopause timing, leading us to hypothesize that the ovarian reserve might signal centrally to trigger puberty. Collectively these findings extend our understanding of the biological complexity of puberty timing and highlight body size dependent and independent mechanisms that potentially link reproductive timing to later life disease.

Brazilian porcupinepox virus infection in a free-ranging neotropical porcupine in Mato Grosso, Brazil.

Although the novel Brazilian porcupinepox virus (BPoPV) can infect wild porcupines, its lethality and zoonotic potential are not well-established. In May 2021, a free-ranging neotropical porcupine (Coendou longicaudatus boliviensis) rescued from the natural savanna in the Brazilian Cerrado, Mato Grosso State, was presented with a lethal poxviral infection. Clinical signs and PCR detection of BPoPV supported the diagnosis. Poxviral lesions included erythema, exfoliative dermatitis, and erosions involving mainly the face, hindlimb, and vulva. Histologically, the lesions consisted of proliferative and necrotic dermatitis, intraepidermal and follicular pustules, and intracytoplasmic inclusion bodies in keratinocytes. Phylogenetic analysis revealed BPoPV strains closely related to other rodent-infecting poxviruses. This poxviral infection resulted in the death of a specimen of C. l. boliviensis; the effect on species conservation, and the potential of spillover into humans and other vertebrates remain unknown.

Effects of cottonseed hull on intake, digestibility, nitrogen balance, blood metabolites and ingestive behaviour of rams.

The aim of this study was to determine the effect of cottonseed hull (CH) in the diets of rams on intake, digestibility, nitrogen balance, ingestive behaviour, and blood metabolites. Twenty males, uncastrated with an average body weight of 29.08 ± 4.18 kg, were distributed in a completely randomized design with four treatment diets and five replicates. The diet contained a forage to concentrate ratio of 50 : 50 (ground corn, soybean meal, corn silage, and CH), and the experimental treatments were inclusion of 0, 10, 20, and 30% CH (dry matter basis). Inclusion of CH linearly increased water intake, effective intake of ethereal extract and non-fibrous carbohydrates, and crude protein digestibility. Dry matter (DM) and neutral detergent fiber (NDF) digestibility, nitrogen faecal losses, and nitrogen balance reduced linearly with CH inclusion in the diet. Inclusion of CH in rams' diet reduces intake, nutrient digestibility, and intake and rumination efficiencies. Thus, it is not recommended to add this by-product to the diet of high-performance rams, but for nurture that does not aim at high performance, inclusion of up to 5% of this by-product is recommended.

Application of highly ozonated sunflower oil does not improve palatal wound healing: A randomized controlled clinical trial.

BACKGROUND: Ozone is a molecule that plays an important role in dentistry, specially for wound healing. The aim of the present study was to clinically and immunologically evaluate the effect of ozonated oil on the healing of palatal wounds. METHODS: This is a prospective, longitudinal, triple-blind, randomized, placebo-controlled clinical trial. The groups were divided as follows: Test group (n = 14): after removal of the free gingival graft (FGG), the palatal wound was treated with ozonized seed sunflower oil with a peroxide index between 510 and 625 meq O2 /kg; Control group (n = 14): after removal of the FGG, the palatal wound was treated with non-ozonated sunflower oil (placebo). The treatments were applied three times a day, for 7 days. RESULTS: There were no significant differences in the measurements of wound area (mm2 ) between the test and control groups in the different periods evaluated (0, 3, 7, and 14 days; p > 0.05). The intra-group analysis showed a significant decrease in wound size over the course of days (0, 3, 7, and 14 days; p < 0.05). Vascular endothelial growth factor (VEGF; pg/mL) presented a significant reduction at 7 days (p < 0.05) compared to day 3 in the test group (p < 0.05). There was a statistical difference for malondialdehyde (MDA; pg/mL) in the test group between 3 and 7 days post-treatment (p < 0.05) and between test and control groups on the 7th day (p < 0.05). CONCLUSIONS: The application of highly ozonated sunflower oil did not improve the remaining scar area of the palate, decreasing the VEGF and increasing the oxidative stress marker MDA.

Therapeutic potential of metal ions for COVID-19: insights from the papain-like protease of SARS-CoV-2.

Coronaviruses have been responsible for multiple challenging global pandemics, including coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Papain-like protease (PLpro), one of two cysteine proteases responsible for the maturation and infectivity of SARS-CoV-2, processes and liberates functional proteins from the viral polyproteins and cleaves ubiquitin and ISG15 modifications to inhibit innate immune sensing. Consequently, PLpro is an attractive target for developing COVID-19 therapies. PLpro contains a zinc-finger domain important for substrate binding and structural stability. However, the impact of metal ions on the activity and biophysical properties of SARS-CoV-2 PLpro has not been comprehensively studied. Here, we assessed the impacts of metal ions on the catalytic activity of PLpro. Zinc had the largest inhibitory effect on PLpro, followed by manganese. Calcium, magnesium, and iron had smaller or no effects on PLpro activity. EDTA at a concentration of 0.5 mM was essential for PLpro activity, likely by chelating trace metals that inhibit PLpro. IC50 values for ZnCl2, ZnSO4, and MnCl2 of 0.42 ± 0.02 mM, 0.35 ± 0.01 mM, and 2.6 ± 0.3 mM were obtained in the presence of 0.5 mM EDTA; in the absence of EDTA, the estimated IC50 of ZnCl2 was 14 µM. Tryptophan intrinsic fluorescence analysis confirmed the binding of zinc and manganese to PLpro, and differential scanning calorimetry revealed that zinc but not manganese reduced ΔHcal of PLpro. The results of this study provide a reference for further work targeting PLpro to prevent and treat COVID-19.

Natural SARS-CoV-2 Infection in a Free-Ranging Black-Tailed Marmoset (Mico melanurus) from an Urban Area in Mid-West Brazil.

The emergence of spillover pathogens such as SARS-CoV-2 is a risk to vulnerable human populations. We report natural SARS-CoV-2 infection in a free-ranging adult female black-tailed marmoset (Mico melanurus) from an urban area of Cuiabá, Mato Grosso State, Brazil. The animal was found after a motor vehicle collision without previous clinical history. Necropsy confirmed polytrauma. Severe multifocal to coalescent haemorrhage and mild multifocal peribronchial lymphocytic hyperplasia were seen in lung sections. The alveolar septa were multifocally expanded by a few lymphocytes. Mild lymphocytic periportal hepatitis and interstitial nephritis were found. The lymphoid nodules of the large intestine showed marked lymphocytic hyperplasia. Infection by SARS-CoV-2 was established by viral RNA detection in a pool of nasopharyngeal and oropharyngeal swabs and liver samples. Immunohistochemistry detected the viral nucleocapsid protein in sections of lung, liver, spleen, lymph nodes and large intestine, and spike protein antigen in lung tissue. This is the first report of naturally occurring SARS-CoV-2 infection in a New World monkey. Platyrrhine species should be included as potential hosts of natural infection of SARS-CoV-2.

Use of the FLOTAC technique as a new coproparasitological diagnostic method in aquatic mammals and comparison with traditional methods.

The inadequate choice of a diagnostic method or the option for techniques that have low sensitivity and specificity may limit the diagnosis of parasitic agents that affect aquatic mammals. The aim of this study was to evaluate the performance of the FLOTAC technique and compare it with three traditional methods (Willis, sedimentation and centrifugation- flotation) used in the diagnosis of gastrointestinal parasites in aquatic mammals. For this, 129 fecal samples from 12 species were collected. Each sample was submitted to laboratory processing using the Willis, Hoffman techniques, Faust method and FLOTAC. Sensitivity, specificity, real prevalence, estimated prevalence, positive predictive value, negative predictive value, correct classification (accuracy) and incorrect classification were evaluated to compare the different diagnostic methods. The highest frequency of positive samples occurred using FLOTAC (46.51%), compared to Hoffman (23.25%), Faust (10.07%) and Willis techniques (6.97%). In the samples analyzed, the occurrence of Strongylidae eggs and Eimeriidae oocysts was frequently observed. The FLOTAC technique proved to be the most appropriate technique and due to its efficacy, is strongly recommended for coproparasitological evaluations in aquatic mammals.

Microbiological Composition of Diets of Cactus Pear-Based with Increasing Levels of Buffel Grass Hay and Relationship to Nutritional Disorders in Sheep.

This study aimed to evaluate the microbiological composition of cactus pear-based diets with increasing levels of buffel grass hay, and its effect on the blood and physiological parameters and occurrence of diarrhea in feedlot sheep. Four diets containing different percentages of buffel grass hay were tested. Diets were composed of forage cactus, buffel grass hay and concentrate, and the treatments were represented by different levels of hay in the dry matter of the feed: 7.5% buffel grass hay; 15% buffel grass hay; 30% buffel grass hay; and 45% buffel grass hay on a dry matter basis. There was a significant effect (p = 0.0034) of inclusion levels of buffel grass hay on fecal score. Only at the 45% inclusion level diarrhea was not observed, showing that the level of buffel grass affected more the animals than the collection period, although the collection period has affected the microbial counts. Probably there was a physiological adaptation of animals over time. There were significant changes (p < 0.0001) in the blood parameters of sheep. The reduction of the proportion of cactus and the inclusion of greater than 15% buffel grass hay, on a dry matter basis, provides less contamination of the diet and animal feces by enterobacteria, such as E. coli.

Profile of T and B lymphocytes in individuals resistant to Schistosoma mansoni infection.

The mechanisms involved in the development of resistance to infection/reinfection by Schistosoma mansoni still arouse great interest and controversy. Some authors demonstrate that resistance to infection is attributed to a mixed Th1 and Th2 response and resistance to reinfection after repeated treatments through mechanisms associated with the Th2 response. Through flow cytometry, the phenotypic characterization of B and T lymphocytes in individuals residing in endemic areas with low parasite loads over 10 years was evaluated for the first time in humans. In this study, individuals with low parasite loads for Schistosoma mansoni had a higher proportion of Th1 and Th2 cells. In addition, lymphocytes from these individuals showed a higher degree of expression of costimulatory molecules CD28 and CTLA-4 and regulatory molecules FoxP3 and IL-10, when compared to individuals with high parasite loads. Our data indicate that the control of the parasite load of S. mansoni must be associated with a Th1, Th2, and regulatory response, and that further studies are needed to elucidate the possibility of mechanisms associated with the hyporesponsiveness of lymphocytes from individuals with high parasite loads.

Successful potassium iodide treatment for rhinofacial pythiosis in sheep.

BACKGROUND: Pythiosis in sheep is an important disease in Brazil, which could cause rhinitis, dermatitis and alimentary tract inflammation. It is caused by the aquatic oomycete, Pythium insidiosum. The rhinofacial pythiosis causes facial deformity and upper respiratory tract clinical signs associated with necroproliferative masses occupying the rostral nasal cavity and hard palate. Little is known regarding the therapy, prophylaxis and pathogenesis of this disease. METHODOLOGY: During the 6-year study, we examined 13 sheep presenting rhinofacial pythiosis. The diagnosis was performed through biopsy of the rhinofacial lesions followed by histopathology and immunohistochemistry using specific antibodies against P insidiosum, polymerase chain reaction and an indirect enzyme-linked immunosorbent assay. RESULTS: This study presents the clinical findings of a potassium iodide treatment of rhinofacial pythiosis in sheep. All sheep were treated with 10 ml of 10% potassium iodide solution, administered orally every day during 63-120 (mean 85) days. Among treated sheep, 84.6% demonstrated complete recovery. CONCLUSION: Potassium iodide therapy may treat rhinofacial pythiosis in sheep.

Ceratocystis cacaofunesta differentially modulates the proteome in xylem-enriched tissue of cocoa genotypes with contrasting resistance to Ceratocystis wilt.

MAIN CONCLUSION: Decreased accumulation of polyphenol oxidase, H2O2 accumulation, effective regulation of programmed cell death, and a protein predicted as allergenic can play key roles in cacao defense against Ceratocystis cacaofunesta. Ceratocystis wilt, caused by the fungus Ceratocystis cacaofunesta, has destroyed millions of Theobroma cacao trees in several countries of the Americas. Through proteomics, systems biology, and enzymatic analyses of infected stems, it was possible to infer mechanisms used by resistant (TSH1188) and susceptible (CCN51) cacao genotypes during infection. Protein extraction from xylem-enriched tissue of stems inoculated with the fungus and their controls 1 day after inoculation was carried out, followed by separation through two-dimensional gel electrophoresis and identification by mass spectrometry. Enzyme activity was determined at 1, 3, 7 and 15 days after inoculation. A total of 50 differentially accumulated distinct proteins were identified in the treatments of both genotypes and were classified into 10 different categories. An interaction network between homologous proteins from Arabidospsis thaliana was generated for each genotype, using the STRING database and Cytoscape software. Primary metabolism processes were apparently repressed in both genotypes. The resistance factors suggested for genotype TSH1188 were: H2O2 accumulation, effective regulation of programmed cell death, production of phytoalexins derived from tryptophan and furanocoumarins, and participation of a predicted allergenic protein with probable ribonuclease function inhibiting the germination and propagation of the fungus. In the susceptible genotype, it is possible that its recognition and signaling mechanism through proteins from the SEC14 family is easily overcome by the pathogen. Our results will help to better understand the interaction between cacao and one of its most aggressive pathogens, to create disease control strategies.

miR-210 and miR-152 as Biomarkers by Liquid Biopsy in Invasive Ductal Carcinoma.

Detecting circulating microRNAs (miRNAs; miRs) by means of liquid biopsy is an important tool for the early diagnosis and prognosis of breast cancer (BC). We aimed to identify and validate miR-210 and miR-152 as non-invasive circulating biomarkers, for the diagnosis and staging of BC patients, confirming their involvement in tumor angiogenesis. METHODS: RT-qPCR was performed and MiRNA expression analysis was obtained from plasma and fragments of BC and benign breast condition (BBC) women patients, plus healthy subjects. Additionally, the immunohistochemistry technique was carried out to analyze the expression of target proteins. RESULTS: Tumor fragments showed increased expression of oncomiR-210 and decreased expression of miR-152 tumoral suppressor. Both miRNAs were increased in plasma samples from BC patients. The receiver operating characteristic (ROC) curve analysis revealed that only the expression of oncomiR-210 in tissue samples and only the expression of the miR-152 suppressor in plasma have the appropriate sensitivity and specificity for use as differential biomarkers between early/intermediate and advanced stages of BC patients. In addition, there was an increase in the expression of hypoxia-inducible factor 1-alpha (HIF-1α), insulin-like growth factor 1 receptor (IGF-1R), and vascular endothelial growth factor (VEGF) in BC patients. On the contrary, a decrease in Von Hippel-Lindau (VHL) protein expression was observed. CONCLUSIONS: This study showed that increased levels of miR-210 and decreased levels of miR152, in addition to the expressions of their target proteins, could indicate, respectively, the oncogenic and tumor suppressive role of these miRNAs in fragments. Both miRNAs are potential diagnostic biomarkers for BC by liquid biopsy. In addition, miR-152 proved to be a promising biomarker for disease staging.

Electrophysiological analysis of stimulus variables in equivalence relations.

Recently, electrophysiological measures have been used to evaluate the functional overlap between semantic relations and laboratory-defined equivalence relations with abstract stimuli. Several studies using semantic judgment procedures have shown that accompanying EEG-measured neural activity for stimulus pairs from equivalence classes is very similar to that of word pairs from participants' native language. However, those studies often included pronounceable elements (e.g., written nonsense syllables) as at least one member of the experimentally defined classes. The present study conducted EEG studies that contrasted classes with and without such elements. Two groups of undergraduate students completed a matching-to-sample procedure to establish 3 4-member equivalence classes. For Group 1, samples and comparisons were pronounceable pseudowords and abstract figures. For Group 2, the matching-to-sample stimuli were abstract figures only. EEG data recorded during the semantic judgment tasks showed waveform patterns compatible with prior studies of semantic relations in Group 1 but not in Group 2.

Chronic copper poisoning in beef cattle in the state of Mato Grosso, Brazil / Intoxicação crônica por cobre em bovinos de corte no Estado de Mato Grosso, Brasil

Copper is an essential micromineral in animal feed; however, when consumed in excess, it can cause liver necrosis, hemolytic crisis, hemoglobinuric nephrosis and death in cattle. Although uncommon in this species, copper poisoning occurs as a result of exacerbated supplementation, deficiency of antagonist microminerals, or previous liver lesions. An outbreak of chronic copper poisoning is reported in semi-confined cattle after supplementation with 50 mg/Kg of dry matter copper. The cattle showed clinical signs characterized by anorexia, motor incoordination, loss of balance, jaundice, brownish or black urine, diarrhea and death, or were found dead, 10 to 302 days after consumption. Of the 35 cattle that died, 20 underwent necropsy, whose frequent findings were jaundice, enlarged liver with evident lobular pattern, black kidneys, and urinary bladder with brownish to blackish content. Microscopically, the liver showed vacuolar degeneration and/or zonal hepatocellular centrilobular or paracentral coagulative necrosis, in addition to cholestasis, mild periacinal fibrosis, apoptotic bodies, and mild to moderate mononuclear inflammation. Degeneration and necrosis of the tubular epithelium and intratubular hemoglobin cylinders were observed in the kidneys. Copper levels in the liver and kidneys ranged from 5,901.24 to 28,373.14 µmol/kg and from 303.72 to 14,021 µmol/kg, respectively. In conclusion, copper poisoning due to excessive nutritional supplementation is an important cause of jaundice, hemoglobinuria, and death in semi-confined cattle.(AU)

Cobre é um micromineral essencial, que quando em excesso induz necrose hepática, crise hemolítica, nefrose hemoglobínurica e morte em bovinos. As intoxicações, apesar de incomuns nessa espécie, ocorrem devido a suplementação exacerbada de cobre, pela deficiência de microminerais antagonistas ou secundária a lesão hepática prévia. Relata-se um surto de intoxicação crônica por cobre em bovinos semiconfinados após suplementação com 50mg/kg de cobre em matéria seca. Os bovinos manifestaram sinais clínicos caracterizados por anorexia, incoordenação motora, perda de equilíbrio, icterícia, urina acastanhada ou negra, diarreia e morte ou foram encontrados mortos, após 10 a 302 dias do início de consumo. De 35 bovinos que morreram 20 foram submetidos à necropsia sendo achada frequente icterícia, fígado aumentado e com padrão lobular evidente, rins pretos e bexiga urinária repleta de conteúdo acastanhado a enegrecida. Microscopicamente, no fígado havia degeneração vacuolar e ou necrose coagulativa hepatocelular zonal, centrolobular ou paracentral, além de degeneração vacuolar com corpúsculos de Councilman, colestase, fibrose periascinar leve, e inflamação de discreta a moderada. Nos rins havia degeneração e necrose do epitélio tubular assim como cilindros de hemoglobina intratubulares. Os níveis de cobre no fígado e rim foram de 5.901,24 a 28.373,14µmol/kg e 303,72 a 14.021µmol/kg respectivamente. A suplementação nutricional excessiva com cobre pode causar doença hemolítica com icterícia, hemoglobinúria e morte de bovinos mantidos em sistema de semiconfinamento.(AU)

Granulomatous pneumonia due to pythiosis in captive South American coatis (Nasua nasua) / Pneumonia granulomatosa decorrente de pitiose em quatis sul-americanos (Nasua nasua) de cativeiro

Pythiosis is an emerging infectious disease affecting captive and free-ranging wild animals. We report granulomatous pneumonia due to Pythium insidiosum in two South American coatis (Nasua nasua), who were found dead without any clinical records. Severe granulomatous pneumonia associated with pleural effusion was revealed in the necropsy. Microscopically, variably sized granulomas and pyogranulomas presented negative hyphae profiles at the periphery of their necrotic cores. Grocott methenamine silver stain highlighted these structures, and immunostain (anti- P. insidiosum) was strongly positive. Molecular analysis by polymerase chain reaction amplified P. insidiosum specific DNA. These findings characterized P. insidiosum as a cause of granulomatous pneumonia in coatis and proved that pythiosis needs to be considered in the differential diagnosis of respiratory diseases affecting this species in endemic areas.(AU)

A pitiose é uma doença infecciosa emergente que afeta animais silvestres de cativeiro e em vida livre. Reportamos dois casos de pneumonia granulomatosa decorrentes da infecção por Pythium Insidiosum em quatis sul-americanos (Nasua nasua), que foram encontrados mortos sem apresentar nenhum quadro clínico prévio. Pneumonia granulomatosa severa associada a efusão pleural foi observada durante a necropsia. Na microscopia, foram observados múltiplos granulomas e piogranulomas de tamanhos variados que continham imagens negativas de hifas na periferia de seus centros necróticos. A coloração de metenamina de prata (Grocott) evidenciou estas estruturas, e a imunomarcação (anti-P. insidiosum) foi fortemente positiva. A análise molecular pela reação de polimerase em cadeia amplificou o DNA específico do P. insidiousum. Estes achados caracterizaram o P. insidiosum como a causa da pneumonia granulomatosa nos quatis e provou que a pitiose deve ser considerada um diagnostico diferencial para outras doenças respiratórias que afetam esta espécie.(AU)

The application of omics in ruminant production: a review in the tropical and sub-tropical animal production context.

The demand for animal products (e.g. dairy and beef) in tropical regions is expected to increase in parallel with the public demand for sustainable practices, due to factors such as population growth and climate change. The necessity to increase animal production output must be achieved with better management and production technologies. For this to happen, novel research methodologies, animal selection and postgenomic tools play a pivotal role. Indeed, improving breeder selection programs, the quality of meat and dairy products as well as animal health will contribute to higher sustainability and productivity. This would surely benefit regions where resource quality and quantity are increasingly unstable, and research is still very incipient, which is the case of many regions in the tropics. The purpose of this review is to demonstrate how omics-based approaches play a major role in animal science, particularly concerning ruminant production systems and research associated to the tropics and developing countries. SIGNIFICANCE: Environmental conditions in the tropics make livestock production harder, compared to temperate regions. Due to global warming, the sustainability of livestock production will become increasingly problematic. The use of novel omics technologies could generate useful information to understand adaptation mechanisms of resilient breeds and/or species. The application of omics to tropical animal production is still residual in the currently available literature. With this review, we aim to summarize the most notable results in the field whilst encouraging further research to deal with the future challenges that animal production in the tropics will need to face.

Effect of observing response requirements to sample and comparison stimuli on the establishment of reject control (sample/S- relations).

The establishment of sample/S- relations (or reject control) during conditional discrimination training (AB, BC) affects transitivity (AC), equivalence (CA) and reflexivity (AA, BB, CC) test outcomes. The present study parametrically evaluated the effects of different observing patterns to comparison stimuli on the establishment of reject control during baseline conditional relation training. A matching-to-sample with observing requirements (MTS-OR) procedure was implemented during AB and BC conditional discrimination training. During training, the participants were required to observe the sample and incorrect comparison on every trial before responding. In addition, the participants were divided into three groups that differed regarding the percentage of training trials on which they were prevented from observing the correct comparison stimuli: 25%, 50%, and 75%. Once the mastery criteria were achieved during training, transitivity (AC), symmetry (BA, CB), equivalence (CA), and reflexivity (AA, BB, CC) tests were conducted with all comparison stimuli visible from the beginning. The results suggest that the number of errors during transitivity, equivalence, and reflexivity tests progressively increased as participants were prevented from observing the correct comparison on a greater number of trials during training. Symmetry test results, however, were not affected by the experimental manipulation. Moreover, the number of participants showing reject-control patterns during tests slightly increased and the number of participants showing select-control patterns decreased as a function of the number of trials on which the participants were prevented from observing the correct comparison. Thus, we suggest that observing patterns during training is a relevant variable that affects equivalence test outcomes.