Migration has an important impact on the transmission of pathogens. Migratory birds disperse parasites through their routes and may consequently introduce them to new areas and hosts. Hence, haemosporidian parasites, which are among the most prevalent, diverse and important bird pathogens, are potentially dispersed when infecting migrant hosts. Further, migrant hosts could enhance local parasite prevalence and richness by transporting new parasite strains to new areas. Here, we hypothesize and aim to evaluate if 1) migratory birds spread parasite lineages along their routes, and 2) localities crossed by more migratory birds have greater prevalence and richness of haemosporidians. For the first hypothesis, we tested whether parasite lineages found 1) in both migrants and residents, and 2) only in residents, differ in their frequencies of occurrence among localities. For the second hypothesis, we tested for a relationship among localities between the overall local haemosporidian parasite richness and prevalence, and the proportion of migratory bird individuals present in a locality. We combined a dataset on 13 200 bird samples with additional data from the MalAvi database (total: ~2800 sequenced parasites comprising 675 distinct lineages, from 506 host species and 156 localities) from South America, and used Bayesian multi-level models to test our hypotheses. We demonstrate that parasites shared between resident and migratory species are the most spatially widespread, highlighting the potential of migrants to carry and transmit haemosporidians. Further, the presence of migrants in a locality was negatively related to local parasite richness, but not associated with local prevalence. Here, we confirm that migrants can contribute to parasite dispersal and visiting migrants are present in regions with lower Plasmodium prevalence. Also, we observed their presence might raise Haemoproteus community prevalence. Therefore, we demonstrate migrants enhance pathogens spread and their presence may influence parasite community transmission. 相似文献
This study evaluated such as exposure to ethinylestradiol during the prenatal (18th–22nd day) and pubertal (42nd–49th day) periods acts on the male ventral prostate and female prostate of 12-month old gerbils. We performed the analysis to serum hormone levels for estradiol and testosterone. The prostates were submitted to morphometric and immunohistochemical analyses. Exposure to ethinylestradiol during these developmental periods decreased the testosterone serum levels in males and increased the estradiol serum levels in females. Morphologically, prostate intraepithelial neoplasia and disorders in the arrangement of the fibrous components were observed in the prostate glands of both sexes of gerbil exposed to ethinylestradiol during development periods. In the male prostate, the ethinylestradiol promoted decreased in the frequency of positive epithelial cell for androgen receptor (AR) and increased the frequency of positive stromal cell for estrogen receptor α. However, in the female prostate, this synthetic estrogen caused AR upregulation and increased cell proliferation. This study shows that the exposure to ethinylestradiol during development phases alters the morphology and the hormonal signaling in the male and female prostates of old gerbils, confirming the action of ethinylestradiol as endocrine disruptor. 相似文献
Limnology - Allochthonous organic matter in low-order streams is, in general, mainly composed of senescent leaves. However, in tropical streams green leaves can represent an important source of... 相似文献
Agoutis, Dasyprocta spp., are medium-sized rodents distributed in Neotropical region. Their diet is usually described as granivorous/frugivorous, and agoutis are recognised as important seed dispersers. Here, we present two spatially and temporally independent records of egg predation by Azara’s agouti, Dasyprocta azarae, in fragments of Cerrado savanna forest. In both cases, the agoutis ingested quail eggs that had been placed in artificial nests at ground level, 100 m from the edge of the forest. As Dasyprocta is a herbivorous rodent, this predatory behaviour is unexpected and may represent an opportunistic foraging strategy. These observations provide important new insights into the feeding biology of agoutis and highlight the value of camera traps as a tool for the collection of data on the behavioural ecology and natural history of vertebrates in general. 相似文献
On a global scale, invasive grasses threaten biodiversity and ecosystem function. Nevertheless, the importation of forage grasses is a significant economic force driven by globalization. Pastureland and rangeland are of critical economic and ecological importance, but novel grass species may lead to invasion. Recognizing that economically important species can also be ecologically damaging creates a contentious debate for land managers, policymakers, and ecologists alike. Many Afrotropical perennial grass species have been intentionally introduced pantropically given their high forage production and resistance to stress. However, these traits may also confer competitive ability, increasing the possibility of unintended escape and invasion. Further, these traits have posed challenges for traditional control methods using chemicals, prescribed fire, and mowing. The use of classic biological control may alleviate the ecological impact in invaded areas. In this literature synthesis we examine Guinea grass (Megathyrsus maximus); whose economic value in many countries is undeniable, yet its impact on native ecosystems is a mounting concern. First, we introduce Guinea grass taxonomy, general biology and ecology, and the geographic and genetic origins. Second, we review the economic value and the ecological impacts. Third, we review the control of Guinea grass in undesired areas using chemical and mechanical means. Finally, we review current efforts to use biological control.
Probiotics and Antimicrobial Proteins - Skin wounds are an important clinical problem which affects millions of people worldwide. The search for new therapeutic approaches to improve wound healing... 相似文献
Probiotics and Antimicrobial Proteins - This study aimed to produce a probiotic-containing functional wheat beer (PWB) by an axenic culture system with potential probiotic Saccharomyces cerevisiae... 相似文献
BackgroundApproximately 70% of cervical carcinoma cases show the presence of high-risk Human Papilloma Virus (HPV), especially HPV-16 and HPV-18, and can be used to stratify high risk patients from low risk and healthy. Currently, molecular biology techniques such as polymerase chain reaction (PCR) are used to identify the presence of virus in patient samples. While the methodology is highly sensitive, it is labor intensive and time-consuming. Alternative techniques, such as vibrational spectroscopy, has been suggested as a possible rapid alternative. Therefore, in this study, we evaluate the efficiency of cervical fluid Fourier Transform Infrared spectroscopy (FTIR) in patient risk stratification informed by PCR.MethodsCervical fluid samples (n = 91) were obtained from patients who have undergone routine Papanicolaou (Pap) test. Viral genome was identified and classified as high/low-risk by PCR-Restriction Fragment Length Polymorphism (PCR-RFLP). FTIR spectra were acquired from samples identified by PCR-RFLP as No-HPV (n = 10), high-risk HPV (n = 7), and low-risk HPV (n = 7).ResultsOf the 91 samples, was detected the viral genome by PCR in 36 samples. Of these 36 samples, nine samples were identified to contain high-risk HPV (HR-HPV) and nine samples were found to have low-risk HPV (LR-HPV). The FTIR spectra acquired from No-HPV, LR-HPV, and HR-HPV showed differences in 1069, 1437, 1555, 1647, 2840, 2919, and 3287 cm-1 bands. Principal Component Analysis (PCA) showed distinct clusters for No-HPV and HR-HPV and No-HPV and LR-HPV, but there was significant overlap in the clusters of HR-HPV and LR-HPV. PCA-Linear Discriminant Analysis (PC-LDA) after Leave One Out Cross Validation (LOOCV) classified No-HPV from HR-HPV and No-HPV from LR-HPV with 100% efficiency in the 1400-1800 cm-1 spectral range. LOOCV classifications for LR-HPV and HR-HPV from each other were 71 and 75%, respectively, in the 2800-3400 cm-1 spectral range.ConclusionsThe results highlight the high sensitivity of PCR-RFLP in HPV identification and show that FTIR can classify samples identified as healthy, low, and high-risk samples by PCR-RFLP.General significanceWe show the possibility of using FTIR for initial cervical cancer risk stratification followed by detailed PCR-RFLP investigations for suspect cases. 相似文献
Currently, there are no reports in the literature demonstrating any animal model that ingests one of the fattiest animal food
source, the bovine brain. We hypothesized that a high-fat diet (HFD), based on dried bovine brain, could be used to develop
an animal model possessing a spectrum of insulin resistance-related features. The HFD was formulated with 40% dried bovine
brain plus 16.4% butter fat, prepared in-house. Furthermore, the diet contained 52% calories as fat and 73% of total fatty acids were saturated. Swiss mice weighing about
40 g were assigned to two dietary groups (n = 6/group), one group received a standard chow diet and the other was given HFD for 3 months. The body weight and biochemical
parameters of the animals were measured initially and at monthly intervals until the end of the experiment. Animals fed on
a HFD showed a significant increase in the body and adipose tissue weight, serum total cholesterol and triglyceride levels,
when compared with mice fed on the control diet. Additionally, the HFD group showed higher circulating levels of liver transaminases,
such as alanine aminotransferase and aspartate aminotransferase, compared with the control group. Finally, to illustrate the
usefulness of this model, we report that the HFD induced mild hyperglycemia, fasting hyperinsulinemia, and increased the homeostasis
model of assessment (HOMA-IR), in comparison with the control group. In conclusion, our results show that HFD, based on dried
bovine brain, causes insulin resistance-related metabolic disturbances. Thus, this may be a suitable model to study disturbances
in energy metabolism and their consequences. 相似文献
Most oil from oceanic spills converges on coastal ecosystems, such as mangrove forests, which are threatened with worldwide
disappearance. Particular bacteria that inhabit the rhizosphere of local plant species can stimulate plant development through
various mechanisms; it would be advantageous if these would also be capable of degrading oil. Such bacteria may be important
in the preservation or recuperation of mangrove forests impacted by oil spills. This study aimed to compare the bacterial
structure, isolate and evaluate bacteria able to degrade oil and stimulate plant growth, from the rhizospheres of three mangrove
plant species. These features are particularly important taking into account recent policies for mangrove bioreme-diation,
implying that oil degradation as well as plant maintenance and health are key targets. Fifty-seven morphotypes were isolated
from the mangrove rhizospheres on Bushneil-Haas (BH) medium supplemented with oil as the sole carbon source and tested for
plant growth promotion. Of this strains, 60% potentially fixed nitrogen, 16% showed antimicrobial activity, 84% produced siderophores,
51% had the capacity to solubilize phosphate, and 33% produced the indole acetic acid hormone. Using gas chromatography, we
evaluated the oil-degrading potential of ten selected strains that had different morphologies and showed Plant Growth Promoting
Rhizobacteria (PGPR) features. The ten tested strains showed a promising degradation profile for at least one compound present
in the oil. Among degrader strains, 46% had promising PGPR potential, having at least three of the above capacities. These
strains might be used as a consortium, allowing the concomitant degradation of oil and stimulation of mangrove plant survival
and maintenance. 相似文献