Pollen and nectar foraging by Melipona quadrifasciata anthidioides Lepeletier (Hymenoptera: Apidae: Meliponini) in natural habitat

This study shows the influence of climatic factors and the nectar and pollen collection by Melipona quadrifasciata in a natural habitat. Five colonies were studied in Parque das Neblinas, Mogi das Cruzes district (23º44’52”S/46º09’46”W), from October 2009 to September 2010. The flight activity of the bees was observed monthly, the temperature and relative humidity were registered using dataloggers and pollen loads were analyzed. The peaks of pollen collection occurred between 8:30-9:50am, while nectar is gathering along the day. The relation of resources sampling and environmental temperature is best described with a polynomial function, while in relation to relative humidity the curves of foraging activity is slightly asymmetric to left. A total of 24 pollen types were identified and the most frequents were Eucalyptus, Melastomataceae, Solanaceae and Myrcia. The tolerance to the environmental conditions is discussed, as well as the plants explored for pollen sources

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Toxicity of bovicin HC5 against mammalian cell lines and the role of cholesterol in bacteriocin activity

Bacteriocins are ribosomally synthesized antimicrobial peptides produced by Bacteria and some Archaea. The assessment of the toxic potential of antimicrobial peptides is important in order to apply these peptides on an industrial scale. The aim of the present study was to investigate the in vitro cytotoxic and haemolytic potential of bovicin HC5, as well as to determine whether cholesterol influences bacteriocin activity on model membranes. Nisin, for which the mechanism of action is well described, was used as a reference peptide in our assays. The viability of three distinct eukaryotic cell lines treated with bovicin HC5 or nisin was analysed by using the MTT assay and cellular morphological changes were determined by light microscopy. The haemolytic potential was evaluated by using the haemoglobin liberation assay and the role of cholesterol on bacteriocin activity was examined by using model membranes composed of DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine) and DPoPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine). The IC50 of bovicin HC5 and nisin against Vero cells was 65.42 and 13.48 µM, respectively. When the MTT assay was performed with MCF-7 and HepG2 cells, the IC50 obtained for bovicin HC5 was 279.39 and 289.30 µM, respectively, while for nisin these values were 105.46 and 112.25 µM. The haemolytic activity of bovicin HC5 against eukaryotic cells was always lower than that determined for nisin. The presence of cholesterol did not influence the activity of either bacteriocin on DOPC model membranes, but nisin showed reduced carboxyfluorescein leakage in DPoPC membranes containing cholesterol. In conclusion, bovicin HC5 only exerted cytotoxic effects at concentrations that were greater than the concentration needed for its biological activity, and the presence of cholesterol did not affect its interaction with model membranes

Safety evaluation of the antimicrobial peptide bovicin HC5 orally administered to a murine model

Bovicin HC5 is an antimicrobial peptide that shows a broad spectrum of activity and potential for biotechnological and therapeutic applications. To gain insight about the safety of bovicin HC5 application, the histological and immunostimulatory effects of orally administrated bovicin HC5 to BALB/c mice were evaluated. BALB/c mice were divided into three groups: negative control (NC group); mice given purified bovicin HC5 (Bov group); mice given ovalbumin (positive control, PC group; a murine model of enteropathy). The mice were initially pre-sensitized, and PBS, bovicin HC5 or ovalbumin were administered for 30 days by daily gavages. Histological and morphometric analysis were performed and the relative expression of cytokines was analyzed by real-time RT-PCR. The oral administration of bovicin HC5 to BALB/c mice reduced weight gain and caused alterations in the small intestine, although absorptive changes have not been detected. The number of total goblet cells and the mucopolysaccharides production were not affected by bovicin HC5 administration. A hypertrophy of Paneth cells and an increase in the number of mitotic cells were observed in Bov group, while the number of mast cells remained unaltered. Increased expression of TNF-α, INF-γ and IL-12 was observed in the small intestine upon bovicin HC5 administration. Bovicin HC5 has only minor effects on intestinal permeability and did not elicit an allergenic response upon oral administration to animal models. Considering the low in vivo toxicity of bovicin HC5, it might be a good candidate for enteral applications

Effects of the oral administration of viable and heat-killed Streptococcus bovis HC5 cells to pre-sensitized BALB/c mice.

Antimicrobial peptides have been suggested as an alternative to classical antibiotics in livestock production and bacteriocin-producing bacteria could be added to animal feeds to deliver bacteriocins in the gastrointestinal (GI) tract of ruminant and monogastric animals. In this study, viable (V) and heat-killed (HK) Streptococcus bovis HC5 cells were orally administered to pre-sensitized mice in order to assess the effects of a bacteriocin-producing bacteria on histological parameters and the immune response of the GI tract of monogastric animals. The administration of V and HK S. bovis HC5 cells during 58 days to BALB/c mice did not affect weight gain, but an increase in gut permeability was detected in animals receiving the HK cells. Viable and heat killed cells caused similar morphological alterations in the GI tract of the animals, but the most prominent effects were detected in the small intestine. The oral administration of S. bovis HC5 also influenced cytokine production in the small intestine, and the immune-mediated activity differed between V and HK cells. The relative expression of IL-12 and INF-γ was significantly higher in the small intestine of mice treated with V cells, while an increase in IL-5, IL-13 and TNF-α expression was only detected in mice treated with HK cells. Considering that even under a condition of severe challenge (pre-sensitization followed by daily exposure to the same bacterial immunogen) the general health of the animals was maintained, it appears that oral administration of S. bovis HC5 cells could be a useful route to deliver bacteriocin in the GI tract of livestock animals

Conscientização dos produtores de leite da Zona da Mata Mineira sobre métodos de prevenção da mastite bovina e isolamento dos seus agentes etiológicos

Erro no DOI, por isso foi disponibilizado o link de acesso.A mastite causa perda da qualidade do leite e riscos à saúde dos consumidores em virtude da presença de resíduos de antibióticos e microrganismos patogênicos, além de sérios prejuízos econômicos tanto para o produtor quanto para a indústria de laticínios. O conhecimento referente aos agentes causadores da doença, à sua evolução clínica e a fatores relacionados com o estabelecimento da infecção deve ser colocado em prática em programas de controle e prevenção da doença, visando o treinamento dos produtores, principalmente em respeito ao manejo adequado de ordenha. Neste trabalho, buscamos conscientizar produtores de leite da Zona da Mata mineira sobre a importância do controle e prevenção de mastite bovina e determinar seus principais agentes etiológicos. Identificamos 3,3% de casos de mastite clínica, 15% de subclínica e 81,7% de tetos sadios em vacas leiteiras da região. Como principais agentes etiológicos, foram isolados o Staphylococcus aureus em 28,52% dos casos e o Staphylococcus sp., coagulase negativa, em 14,83%. Observamos também que poucos produtores da região possuem conhecimentos básicos sobre os métodos de prevenção e controle da mastite. Sendo assim, muitos carecem de programas de assistência técnica especializada, o que seria útil para o desenvolvimento de suas comunidades.Mastitis causes loss of milk quality, health risks to consumers due to antibiotic residues and pathogenic microbes, and serious economic losses to both the grower and the dairy industry. The knowledge related to the causative species of the disease, clinical evolution and factors that favour the establishment of the infection should be prioritized. Improved control programs and disease prevention should be put into practice, aiming the suitable training of the producers, mainly referring to the proper handling of milking. In this work, we seek to carry out an awareness of the importance of bovine mastitis control and prevention in the Zona da Mata mineira and to determine the main etiological agents. We identified 3.3% of cases of clinical mastitis, 15% subclinical and 81.7% of ceiling healthy. The main etiologic agents were Staphylococcus aureus isolated in 28.52% of cases and Saphylococcus sp., coagulase negative, 14.83%. We also observed that few producers in the region have basic knowledge about methods of mastitis prevention and control. Thus, many programs lack the specialized technical assistance, which would be useful for the development of their communities

Number of total spleen cells among the experimental groups.

<p>Data represent the average±SEM. Differences among treatments were indicated by different lowercase letters and were considered statistically significant by the Dunn's multiple comparison test (p<0.05). (NC) negative control group; (V) mice treated with viable <i>S. bovis</i> HC5 cells; (HK) mice treated with heat-killed <i>S. bovis</i> HC5 cells.</p