Stable isotopes reveal niche segregation between native and non-native Hoplias in a Neotropical floodplain     

Gustavo H. Zaia Alves  Vivian M. Cionek  Gislaine I. Manetta  Laryssa H. R. Pazianoto  Evanilde Benedito 《Ecology of Freshwater Fish》2020,29(4):602-610

We investigated whether isotopic niche partitioning could mediate the coexistence between native (Hoplias sp. B) and non-native (Hoplias mbigua) trahira in a Neotropical floodplain. We hypothesised that during the dry season both species inhabit isolated sites (i.e. lakes) and thus rely on distinct food resources to sustain their coexistence. We found evidence of trophic segregation among native and non-native freshwater fish in the Upper Paraná River, Brazil. Even though both species rely on the same primary littoral carbon sources and present similar trophic diversity, trophic segregation was attained through larger niche amplitude and smaller isotopic niche width for the non-native fish. Three decades after initial invasion, non-native Hoplias have distinct foraging behaviour and do not compete for trophic resources with native trahira; this is likely due to morpho-anatomical differences. Limited morphological similarity between these congeneric species might be the strongest factor contributing to their coexistence in the Paraná River floodplain during the dry season.  相似文献   

Plasma malonaldehyde (MDA) and total antioxidant status (TAS) during lactation in dairy cows     

Castillo C  Hernández J  Valverde I  Pereira V  Sotillo J  Alonso ML  Benedito JL 《Research in veterinary science》2006,80(2):133-139

Metabolic profiles are widely used to monitor health, reproductive status and nutritional status. In the last few years, the evaluation of oxidative stress has contributed increasingly to our knowledge of the fundamental mechanisms involved in metabolic disorders, especially important in dairy cows, in which lactation imposes great physiological demands on the body's homeostatic mechanisms. The aim of the present study was to evaluate oxidative status in healthy cows during lactation (from lactation onset to peak lactation) using two parameters: (i) plasma levels of malondialdehyde (MDA) and (ii) total antioxidant status (TAS). Our results confirm that nutrition can influence the characteristic metabolic changes occurring between lactation onset and peak lactation. In addition, the combination of MDA and TAS can provide complementary information about the metabolic status of the cow. Thus, the proper metabolic adaptation to the onset of lactation, showed by metabolic profiles, contrasts with the high levels of free radicals which cause lipid peroxidation and high MDA values (68.99+/-33.64 microm/L) which is maintained only for a short period of time. In this moment, the antioxidant system can cope efficiently with lipoperoxide production. The most remarkable fact was the great inter-individual variations observed in MDA that might be studied in further investigations. When the animal reaches peak lactation, metabolic status is stabilized, and this is reflected by antioxidant status with mean values of 28.87+/-5.33 microm/L for MDA and 0.154+/-0.002 mmol/L for TAS values.  相似文献   

A comparison of the effects of two different doses of ketamine used for co-induction of anaesthesia with a target-controlled infusion of propofol in dogs   总被引：1，自引：0，他引：1  

Alastair R Mair BVM&S  Cert VA  MRCVS    Patricia Pawson BVMS  Diplomate ECVAA  PhD  MRCVS    Emily Courcier† BVetMed  BSc  MRCVS  & Derek Flaherty BVMS  Diplomate ECVAA  DVA  MRCA  MRCVS 《Veterinary anaesthesia and analgesia》2009,36(6):532-538

ObjectiveTo assess the cardiorespiratory and hypnotic-sparing effects of ketamine co-induction with target-controlled infusion of propofol in dogs.Study designProspective, randomized, blinded clinical study.AnimalsNinety healthy dogs (ASA grades I/II). Mean body mass 30.5 ± SD 8.6 kg and mean age 4.2 ± 2.6 years.MethodsAll dogs received pre-anaesthetic medication with acepromazine (0.03 mg kg^?1) and morphine (0.2 mg kg^?1) administered intramuscularly 30 minutes prior to induction of anaesthesia. Heart rate and respiratory rate were recorded prior to pre-medication. Animals were allocated into three different groups: Group 1 (control) received 0.9% NaCl, group 2, 0.25 mg kg^?1 ketamine and group 3, 0.5 mg kg^?1 ketamine, intravenously 1 minute prior to induction of anaesthesia, which was accomplished using a propofol target-controlled infusion system. The target propofol concentration was gradually increased until endotracheal intubation was possible and the target concentration at intubation was recorded. Heart rate, respiratory rate and noninvasive blood pressure were recorded immediately prior to induction, at successful intubation and at 3 and 5 minutes post-intubation. The quality of induction was graded according to the amount of muscle twitching and paddling observed. Data were analysed using a combination of chi-squared tests, Fisher's exact tests, Kruskal–Wallis, and anova with significance assumed at p< 0.05.ResultsThere were no significant differences between groups in the blood propofol targets required to achieve endotracheal intubation, nor with respect to heart rate, noninvasive blood pressure or quality of induction. Compared with the other groups, the incidence of post-induction apnoea was significantly higher in group 3, but despite this dogs in this group had higher respiratory rates overall.Conclusions and clinical relevanceUnder the conditions of this study, ketamine does not seem to be a useful agent for co-induction of anaesthesia with propofol in dogs.  相似文献   

Acid–base status and serum l-lactate in growing/finishing bull calves fed different high-grain diets     

C. Castillo  J.L. Benedito  V. Pereira  P. Vázquez  C. Gutiérrez  J. Hernández 《Livestock Science》2009,120(1-2):66-74

This study evaluated the influence of diet grain mix on the serum acid–base balance and productive performance of calves maintained on high-grain diets in a commercial feedlot system, monitoring progress over the entire 140-day productive cycle (i.e. both the growing and finishing periods). Thirty 14-week-old Belgian Blue bull calves were randomly allotted in equal numbers to one of three experimental groups defined by whether the cereal grain in their diet was predominantly corn (group C), predominantly barley (group B), or predominantly a mixture of corn and barley in approximately equal proportions (group CB). Blood pH, pCO₂, HCO₃^?, base excess and serum l-lactate were determined, as were several productive performance variables. The three groups differed significantly with respect to their weights at the end of the growing period (CB > C > B), but not in final weight; group B gained significantly more weight and had a lower daily intake than either group C or group CB during the finishing period. At no time during the study period was altered ruminal function suggested by either clinical signs or blood parameters, possibly because of the relatively high crude protein (CP) contents of the feeds and the use of barley straw as forage. Nevertheless, HCO₃^? and base excess were significantly higher in group C than in the other groups during the growing period, suggesting that supplementation of a high-CP corn-based diet with bicarbonate could lead to alkalotic blood base values (group C was the only group to receive bicarbonate supplement in this study). Also, in group CB HCO₃^? and base excess were generally lower than in the other groups during both the growing and finishing periods, much of the time exhibiting a falling trend compatible with the use of blood bases to counteract overproduction of ruminal acids; this behaviour, which may have been due to the lower dietary fibre content of the CB diet, does not support claims that diets with equal proportions of rapidly and slowly digested starch sources are more beneficial than those including only one of these starch source types. Serum l-lactate levels were almost invariably higher in group B than in group C, with group CB in between, in both the growing and the finishing periods; and a significant time × group interaction during the growing period suggests that the time course of serum l-lactate was determined mainly by the influence of diet on microbial growth rates in the rumen. Negative correlation between blood pH and pCO₂ around the switch between growing and finishing regimens suggests that diet may possibly modulate the influence of breed on pCO₂, but further is required to examine this hypothesis.  相似文献   

Characterization of aflatoxigenic and non-aflatoxigenic strains of <Emphasis Type="Italic">Aspergillus</Emphasis> section <Emphasis Type="Italic">Flavi</Emphasis> isolated from corn grains of different geographic origins in Brazil     

Liliana de Oliveira Rocha  Gabriela Martins Reis  Raquel Braghini  Estela Kobashigawa  Jansen de Araújo  Benedito Corrêa 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(3):353-366

Aflatoxins can cause great economic losses and serious risks to humans and animals health. The largest aflatoxin producers belong to Aspergillus section Flavi and can occur naturally in food commodities. Studies showed that molecular tools as well as the type of sclerotia produced by the strains could be helpful for identification of Aspergillus species and could be correlated with levels of toxin production. The purpose of this work was to characterize the genetic diversity using AFLP technique, the type of sclerotia and the ability of aflatoxin production by isolated strains from corn of different origins in Brazil, and to verify whether qPCR based on aflR and aflP genes is appropriate for estimating the level of aflatoxin production. All the 75 strains were classified as A. flavus and the AFLP technique showed a wide intraspecific variability within them. Regarding sclerotia production, 34% were classified as S and 66% as L type. Among the aflatoxin-producers, 52.8% produced aflatoxin B₁, while 47.2% aflatoxins B₁ and B₂. Statistical analysis showed no correlation between sclerotia production and aflatoxigenicty, and no correlation between the phylogenetic clusters and aflatoxin production. Concerning the relative expression of aflR and aflP, Pearson’s correlation test demonstrated low positive correlation between the expression of the aflR and aflP genes and the production of AFB₁ and AFB₂, but showed high positive correlation between aflR and aflP expression. In contrast to the other reference strains, A. oryzae ATCC 7282 showed no amplification of aflR and aflP. The results highlight the need for detection of reliable and reproducible markers with a high positive correlation with aflatoxin production.  相似文献   

Rabies virus and Histoplasma suramericanum coinfection in a bat from southeastern Brazil     

Benedito Donizete Menozzi  Giselle Souza da Paz  Laís Moraes Paiz  Hans Garcia Garces  Brunna Mayla Vasconcelos Adorno  Fernando Almeida‐Silva  Rosely Maria Zancope Oliveira  Virgínia Bodelo Richini‐Pereira  Jssica Luana Chechi  Eduardo Bagagli  Sandra de Moraes Gimenes Bosco  Helio Langoni 《Zoonoses and public health》2020,67(2):138-147

Bats are essential to the global ecosystem, but their ability to harbour a range of pathogens has been widely discussed, as well as their role in the emergence and re‐emergence of infectious diseases. This paper describes the first report of coinfection by two zoonotic agents, rabies virus (RABV) and the fungus Histoplasma suramericanum in a bat. The bat was from the Molossus molossus species, and it was found during the daytime in the hallway of a public psychiatric hospital in a municipality in São Paulo State, southeastern Brazil. RABV infection was diagnosed by the direct fluorescent antibody test and mouse inoculation test. The fungus was isolated by in vitro culture. Both diagnoses were confirmed by molecular techniques. Phylogenetic analysis showed that the fungus isolate had proximity to H. suramericanum in the Lam B clade, while the RABV isolate was characterized in the Lasiurus cinereus lineage. Since the M. molossus bat was found in a peri‐urban transition area (urban/peri‐urban), the possibility of cross‐species transmission of this RABV lineage becomes more plausible, considering that this scenario may provide shelter for both M. molossus and L. cinereus. These are relevant findings since there has been an increase in bat populations in urban and peri‐urban areas, particularly due to environmental modifications and anthropogenic impacts on their habitat. Thus, the detection of two zoonotic agents in a bat found in a public hospital should raise awareness regarding the importance of systematic surveillance actions directed towards bats in urban areas.  相似文献   

Spatial patterns of magnetic susceptibility optimized by anisotropic correction in different Alisols in southern Amazonas,Brazil     

Brito  Wildson Benedito Mendes  Campos  Milton César Costa  de Souza  Fernando Gomes  Silva  Laércio Santos  da Cunha  José Maurício  de Lima  Alan Ferreira Leite  Martins  Thalita Silva  de Oliveira  Flávio Pereira  de Oliveira  Ivanildo Amorim 《Precision Agriculture》2022,23(2):419-449

Precision Agriculture - Changes in primary cover for agricultural crops in Amazonas region influence the phenomenon of spatial variability in soil properties. This phenomenon is still studied...  相似文献   

The importance of the oxidative status of dairy cattle in the periparturient period: revisiting antioxidant supplementation          下载免费PDF全文

A. Abuelo  J. Hernández  J. L. Benedito  C. Castillo 《Journal of animal physiology and animal nutrition》2015,99(6):1003-1016

Dairy cows are especially vulnerable to health disorders during the transition period, when they shift from late pregnancy to the onset of lactation. Diseases at this stage affect not only the animals' well‐being, but also cause a major economic impact in dairy farms, because apart from treatment costs, affected cows will not reach their peak milk‐producing capacity. The overproduction of reactive oxygen species (ROS) leads to oxidative stress, which has been identified as an underlying factor of dysfunctional inflammatory responses. Supplementation with vitamins and trace elements attempts to minimize the harmful consequences of excessive ROS production, thereby trying to improve animals' health status and to reduce disease incidence. However, results regarding the effects of supplementing antioxidants on dairy cows' health and performance have been inconsistent, because in most cases, the antioxidant potential of the animals was not assessed beforehand and the nutritional strategy planned accordingly. Therefore, reviewing the physiological and harmful effects of ROS production, along with the different options available for assessing the redox balance in dairy cattle and some of the key findings of different supplementation trials, could bring one step forward the on‐farm application of determinations of oxidative status for establishing nutritional strategies early enough in the dry period that could improve transition cow health.  相似文献   

Seasonal variability of a conditional stability constant and the characterization of sedimentary humic substances from typical agricultural and urban areas     

Glaucia Pantano  Amanda Maria Tadini  Márcia Cristina Bisinoti  Altair Benedito Moreira 《Journal of Soils and Sediments》2014,14(2):385-393

Purpose

Brazil is the largest producer of sugarcane in the world. This extensive production of sugarcane has changed the use and form of Brazilian soil, causing changes in the structural characteristics of humic substances (HS). In this context, the main objective of this study was to evaluate the effect of seasonality on a conditional stability constant (Kc) of the complexes HS-Cu (II) and HS-Cr (III) from the HS of urban and agricultural regions, with an emphasis on sugarcane culture.

Materials and methods

The study was conducted in the northwestern region of the state of São Paulo, which is the leading producer of sugar and ethanol in the country and is the region with the lowest percentage of riparian vegetation (3 %). Sediments were sampled during the rainy and dry seasons at four locations: (1) a typical agricultural area, (2) an urban area, (3) a sugarcane cultivation area, (4) and an area that receives the entire pollutant load from the hydrographic basin. The HS were extracted and characterized using conventional techniques. The Kc of the HS with copper (Cu) and chromium (Cr) ions was determined by fluorescence suppression employing the Stern–Volmer model.

Results and discussion

Kc values were higher in the rainy seasons for HS-Cu (II) and HS-Cr (III). The highest value of Kc for the HS with Cu (1.23) and Cr (5.2?×?10^?1) ions was found during the rainy season in the area receiving the pollutant load from the basin and in the typical area of sugarcane cultivation, respectively. All of the FTIR spectra showed characteristic bands of HS, and the values of the E₄/E₆ ratio confirmed the presence of more aromatic groups. An elemental analysis and molecular fluorescence spectra in the emission mode confirmed that the HS from the agricultural area and sugarcane culture area mostly exhibited characteristics of humic acids and that the HS from the urban area and the area receiving the pollutant load from the basin had a mixture of humic and fulvic acids.

Conclusions

We can conclude that HS–metal complexes from the area that received the entire load of pollutants from the watershed and the typical area of sugarcane culture showed the highest stability among the study areas. The Kc values found in the basin were lower than those previously obtained by several studies that were performed in other locations. The HS obtained in rainy season had more aromatic groups in the HS structure, and the HS from the sugarcane area presented more characteristics of humic acids.  相似文献   

Comparison between cachaça and rum using pattern recognition methods     

Cardoso DR  Andrade-Sobrinho LG  Leite-Neto AF  Reche RV  Isique WD  Ferreira MM  Lima-Neto BS  Franco DW 《Journal of agricultural and food chemistry》2004,52(11):3429-3433

The differentiation between cacha?a and rum using analytical data referred to alcohols (methanol, propanol, isobutanol, and isopentanol), acetaldehyde, ethyl acetate, organic acids (octanoic acid, decanoic acid, and dodecanoic acid), metals (Al, Ca, Co, Cu, Cr, Fe, Mg, Mn, Ni, Na, and Zn), and polyphenols (protocatechuic acid, sinapaldehyde, syringaldehyde, ellagic acid, syringic acid, gallic acid, (-)-epicatechin, vanillic acid, vanillin, p-coumaric acid, coniferaldehyde, coniferyl alcohol, kaempferol, and quercetin) is described. The organic and metal analyte contents were determined in 18 cacha?a and 21 rum samples using chromatographic methods (GC-MS, GC-FID, and HPLC-UV-vis) and inductively coupled plasma atomic emission spectrometry, respectively. The analytical data of the above compounds, when treated by principal component analysis, hierarchical cluster analysis, discriminant analysis, and K-nearest neighbor analysis, provide a very good discrimination between the two classes of beverages.  相似文献