The ecological impacts of alien species invasion are a major threat to global biodiversity. The increasing number of invasion events by alien species and the high cost and difficulty of eradicating ...invasive species once established require the development of new methods and tools for predicting the most susceptible areas to invasion. Invasive pollinators pose serious threats to biodiversity and human activity due to their close relationship with many plants (including crop species) and high potential competitiveness for resources with native pollinators. Although at an early stage of expansion, the bumblebee species Bombus terrestris is becoming a representative case of pollinator invasion at a global scale, particularly given its high velocity of invasive spread and the increasing number of reports of its impacts on native bees and crops in many countries. We present here a methodological framework of habitat suitability modeling that integrates new approaches for detecting habitats that are susceptible to Bombus terrestris invasion at a global scale. Our approach did not include reported invaded locations in the modeling procedure; instead, those locations were used exclusively to evaluate the accuracy of the models in predicting suitability over regions already invaded. Moreover, a new and more intuitive approach was developed to select the models and evaluate different algorithms based on their performance and predictive convergence. Finally, we present a comprehensive global map of susceptibility to Bombus terrestris invasion that highlights priority areas for monitoring.
Prenatal heat stress during late gestation exerts long-term effects on growth and productivity of the dairy calf. Further, direct exposure to heat stress during the preweaning period impairs calf ...thermoregulation and performance. We examined the effects of heat stress abatement during the prenatal period, postnatal period, or both on calf performance. We hypothesized that calves exposed to pre- and postnatal heat stress abatement would perform most optimally in terms of thermoregulation, growth, and health responses when compared with calves that are heat-stressed at any time in the pre- or postnatal periods. Holstein calves born to heat-stressed (HT) or cooled (CL) dams during late gestation (44 ± 5 d; prenatal HT or CL) were exposed to heat stress or cooling postnatally for 56 d (postnatal HT or CL), resulting in 4 treatments: HT-HT, HT-CL, CL-HT, and CL-CL; n = 12/treatment. Calves were administered 4 L of pooled colostrum and after 2 d of age allotted 10 L/d milk replacer and up to 3 kg/d concentrate in automatic feeder group pens (n = 6/pen). Postnatal cooling was achieved by 2 fans (average wind speed 2 m/s). Thermoregulatory responses (respiration rate and heart rate; rectal, body, and skin temperature), feed intake, growth parameters including average daily gain and medication events were recorded, and blood samples were collected weekly. Thermoregulatory responses were lower in postnatal CL calves compared with postnatal HT. In the afternoon, HT-HT calves had the highest respiration rate and rectal temperature, HT-CL calves had the lowest respiration rate, and CL-HT calves had the lowest heart rate compared with the other treatment groups. Prenatal CL calves weighed more at birth and weaning with a tendency for greater average daily gain compared with prenatal HT calves, whereas postnatal CL calves had increased milk replacer and concentrate intake and a tendency for reduced fever, infection, and total medication events relative to postnatal HT. Prenatal HT calves were esophageal tube fed more often than prenatal CL. Blood hematocrit and 24-h serum IgG concentration were greater in prenatal CL calves relative to prenatal HT. Prenatal heat stress abatement improves weight gain, hematocrit, and immunoglobulin transfer, whereas postnatal heat stress abatement modulates thermoregulatory responses, feed intake, and calf health. This study is the first to characterize the combined effects of pre- and postnatal heat stress or active cooling on the dairy calf.
We prove Lp norm convergence for (appropriate truncations of) the Fourier series arising from the Dirichlet Laplacian eigenfunctions on three types of triangular domains in $\mathbb{R}^2$: (i) the ...45-90-45 triangle, (ii) the equilateral triangle and (iii) the hemiequilateral triangle (i.e. half an equilateral triangle cut along its height). The limitations of our argument to these three types are discussed in light of Lamé’s Theorem and the image method.
Cocoa shell (CS) is a by-product of the chocolate industry with limited economic benefit and a high environmental impact. In this study, a new material for the food industry that consists of ...nanocellulose fibers with CS fat was successfully isolated (yield of approximately 7.12%). The material was characterized with attenuated total reflection–Fourier transform infrared spectroscopy (ATR–FTIR), solid-state
13
C nuclear magnetic resonance (
13
C NMR), X-ray diffraction (XRD), fluorescence and atomic force microscopy (AFM). The XRD,
13
C NMR, and ATR–FTIR results suggest that the structure of the cellulosic CS fibers can be interpreted as cellulose I
β
. The crystallinity index (CrI) of an isolated sample was investigated by different methods with ATR–FTIR,
13
C NMR, and XRD. According to the results,
13
C NMR and XRD are the most adequate methods for quantifying the CrI of cellulosic samples in the presence of fat. In addition, the XRD results indicate that approximately 65 to 70% of the sample was crystalline. According to the fluorescence microscopy results, the cellulosic sample formed a suspension with fat, and the AFM results show that the cellulosic part of the sample had nanometric diameters between 30–80 nm with high aspect ratios. Consequently, a suspension of nanocellulose, hemicellulose, and fat was isolated from CS by chemical and mechanical treatments. The new material can be called a “suspension of holocellulose nanofibers and fat” owing to its composition and fiber diameters. The high aspect ratio of the nanocellulose fibers in the suspension resulted in an entangled network that stabilized the CS fat.
Mesh based methods such as the finite element method (FEM) are the most usually used techniques for analysing soil-structure interaction problems in geotechnical engineering. Nevertheless, standard ...FEM is unable to simulate large deformations and contact, hindering the realistic simulation of rotational, sliding, pull-out and overturning behaviours. Contemporary ‘particle’ methods, such as the material point method (MPM), do not use a mesh to discretise the material, allowing large deformations to be simulated. In this paper, a recently developed technique to simulate contact using implicit MPM is tested by simulating soil-structure interaction problems and a landslide. First, the behaviour of a retaining structure is studied during the impact of a mass of soil for different foundation conditions. Then, a landslide triggered by construction procedures is analysed. This new formulation allows the development of deep and shallow complex failure mechanisms (a combination of passive and active soil failures) and therefore the means to assess the consequences of a slope failure.
•Consequences of landslides are only captured through large deformation analysis.•Soil-structure interaction problems are better studied by adding a contact formulation.•The material point method can capture multiple slope failure mechanisms as observed in nature.
Ecosystem services provided by mobile agents are increasingly threatened by the loss and modification of natural habitats and by climate change, risking the maintenance of biodiversity, ecosystem ...functions, and human welfare. Research oriented towards a better understanding of the joint effects of land use and climate change over the provision of specific ecosystem services is therefore essential to safeguard such services. Here we propose a methodological framework, which integrates species distribution forecasts and graph theory to identify key conservation areas, which if protected or restored could improve habitat connectivity and safeguard ecosystem services. We applied the proposed framework to the provision of pollination services by a tropical stingless bee (Melipona quadrifasciata), a key pollinator of native flora from the Brazilian Atlantic Forest and important agricultural crops. Based on the current distribution of this bee and that of the plant species used to feed and nest, we projected the joint distribution of bees and plants in the future, considering a moderate climate change scenario (following IPPC). We then used this information, the bee's flight range, and the current mapping of Atlantic Forest remnants to infer habitat suitability and quantify local and regional habitat connectivity for 2030, 2050 and 2080. Our results revealed north to south and coastal to inland shifts in the pollinator distribution during the next 70 years. Current and future connectivity maps unraveled the most important corridors, which if protected or restored, could facilitate the dispersal and establishment of bees during distribution shifts. Our results also suggest that coffee plantations from eastern São Paulo and southern Minas Gerais States could suffer a pollinator deficit in the future, whereas pollination services seem to be secured in southern Brazil. Landowners and governmental agencies could use this information to implement new land use schemes. Overall, our proposed methodological framework could help design novel conservational and agricultural practices that can be crucial to conserve ecosystem services by buffering the joint effect of habitat configuration and climate change.
In North Africa, and especially in the Sahara Desert, biodiversity is poorly known. Of the five widespread canid species present, one is Data Deficient, three are considered widespread although ...habitat selection could limit their area of occupancy, and distribution maps available are coarse for conservation planning. This study identifies biogeographic patterns in North-African canids through the combination of high resolution presence data with 16 environmental factors. Predictive models trained in north-west Africa are projected to all North Africa. canids exhibited distinct biogeographical affinities. GIS tools and Maximum Entropy models identify a mixture of climatic and habitat factors as main predictors of species occurrence. Suitable habitats for North-African canids are mostly fragmented: probable occurrence was identified for
Canis aureus in Saharan peripheral regions and mountains, for
Vulpes pallida in a narrow band along the Sahel and in southern Saharan mountains, for
Vulpes rueppellii throughout the Sahara, for
Vulpes vulpes in northern Africa until the Sahara northern limit, and for
Vulpes zerda in almost all Sahara. Areas of potential sympatry between species with similar niches and parapatric ranges are identified along relatively narrow bands. The small pixel size of projections allows the identification of suitable refuges for species otherwise absent in the driest Saharan habitats, providing framework data for the definition of the global conservation status of
V. pallida, and conservation strategies for the guild. The biological value of Saharan mountains is emphasised as they constitute isolated suitable areas. Ecological-niche based models should be developed for other endangered Saharan vertebrates.
Connexin43 hemichannels have been implicated in many inflammatory diseases including diabetic retinopathy (DR). Particularly, hemichannel-mediated ATP release has been associated with inflammasome ...pathway activation. Using an in vitro cell culture model, we evaluated hemichannel roles in response to inflammatory cytokines under high glucose (HG) conditions and propose a mechanism by which a connexin43 hemichannel-mediated autocrine ATP feedback loop augments chronic inflammatory disease.
Retinal pigment epithelial cells were exposed to HG, 10ng/mL pro-inflammatory cytokines IL-1β and TNF-α, or a combination of both. Quantitative Cytometric Bead Array analysis was used to measure the release of inflammatory cytokines IL-6, IL-8, MCP-1, and sICAM-1, as well as VEGF and ATP. To determine the role of connexin43 hemichannels in the disease process, changes in cytokine and ATP release were evaluated following treatment with Peptide5, a connexin43 hemichannel blocker. Immunohistochemistry was used to compare NLRP3 inflammasome assembly under control and treatment conditions.
Co-application of HG and cytokines increased the secretion of IL-6, IL-8, MCP-1, sICAM-1, VEGF and ATP, to significantly higher levels compared to cytokines alone. Peptide5 prevented cytokine release and prevented the increase in ATP release following co-application of HG and cytokines. Adding exogenous ATP negated Peptide5-mediated protection against inflammatory cytokine release in injury conditions.
Our findings show that connexin43 hemichannels play an important role in the amplification and perpetuation of inflammation by mediating an ATP autocrine feedback loop in the inflammasome/inflammation cycle.
Targeting connexin43 hemichannels offers a potential therapeutic strategy to break the inflammatory cycle in diseases such as DR, but also other chronic inflammatory indications.
•Hyperglycaemia and inflammation synergistically increase inflammatory cytokine release.•Peptide5, a connexin43 hemichannel blocker, decreases inflammatory cytokine and ATP release.•Exogenous ATP reverses Peptide5 protection.•Connexin43 hemichannel mediated ATP release amplifies the inflammasome response in an autocrine fashion.
Objective: The performance of an EEG-based brain-computer interface (BCI) system is highly dependent on signal preprocessing. This manuscript presents a filtering method to improve the feature ...classification algorithms typically used in BCI. Methods: A graph Laplacian quadratic form using the Phase Locking Value (PLV) is applied to generate a new filtered signal in the preprocessing stage. Results: The accuracy of the classification algorithms improved significantly (up to 27.18% in the BCI Competition IV dataset, and up to 42.56% with records made with an Emotiv EPOC+). In addition, the proposed filtering algorithm has similar or better results when compared with the Filter Bank Common Spatial Pattern (FBCSP), which has disadvantages in a multiclass classification. Conclusion: This paper shows how our PLV-based filtering between EEG channels could improve the performance of a BCI.
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