Defensive behavioral patterns in response to human-induced rapid environmental change can affect animals’ fitness and may play a role in species conservation status. To test this hypothesis, we compared the risk assessment and defensive behavioral responses of captive white-lipped peccary (WLP; Tayassu pecari) and collared peccary (CP; Pecari tajacu), which retain different conservation status; WLP are considered vulnerable and CP of least concern. We used an adapted paradigm of the mouse defense test battery (MDTB) comprising four consecutive tests. Two of these tests simulated a novel environment, while the other two stimulated the expression of defensive behavioral patterns. Besides differences in risk assessment and defensive threat/attack behavioral patterns between species, we compared flight initiation distance, flight speed, and plasma glucocorticoid concentrations. When facing a novel environment and risk challenges from humans’ predator-like cues, the white-lipped peccary showed more exploratory and defensive threat/attack behavioral patterns, shorter flight initiation distances, and lower flight speeds, whereas the collared peccaries showed more cautious and retreat patterns, longer flight initiation distances, and higher flight speeds. There were also correlations between physiological and behavioral parameters. We confirmed our hypothesis that the collared peccary’s cautiousness may help to prevent a decrease in its population, while the white-lipped peccary’s exploratory and confrontational behavioral patterns in overhunted areas, together with other simultaneous factors as forest fragmentation, might contribute to placing this species in the vulnerable category. 相似文献
Biodegradation of phenolic compounds in bioreactors is well documented, but the changes in the bacterial populations dynamics during degradation were not that often. A glass bubble column used as reactor was inoculated with activated sludge, spiked with 2-chlorophenol, phenol and m-cresol after 28 days and maintained for an additional 56 days, while the 16S rRNA gene from metagenomic DNA was monitored. Proteobacteria (68.1%) dominated the inoculum, but the bacterial composition changed rapidly. The relative abundance of Bacteroidetes and Firmicutes decreased from 4.8 and 9.4 to <0.1 and 0.2% respectively, while that of Actinobacteria and TM7 increased from 4.8 and 2.0 to 19.2 and 16.1% respectively. Phenol application increased the relative abundance of Proteobacteria to 94.2% (mostly Brevundimonas 17.6%), while that of Bacteroidetes remained low (1.2%) until day 42. It then increased to 47.3% (mostly Leadbetterella 46.9%) at day 84. It was found that addition of phenolic compounds did not affect the relative abundance of the Alphaproteobacteria initially, but it decreased slowly while that of the Bacteroidetes increased towards the end.
The decapeptide killer peptide (KP) derived from the sequence of a single-chain, anti-idiotypic antibody acting as a functional internal image of a microbicidal, broad-spectrum yeast killer toxin (KT) was shown to exert a strong microbicidal activity against human pathogens. With the aim to exploit this peptide to confer resistance to plant pathogens, we assayed its antimicrobial activity against a broad spectrum of phytopathogenic bacteria and fungi. Synthetic KP exhibited antimicrobial activity in vitro towards Pseudomonas syringae, Erwinia carotovora, Botrytis cinerea, and Fusarium oxysporum. KP was also expressed in plants by using a Potato virus X (PVX)-derived vector as a fusion to the viral coat protein, yielding chimeric virus particles (CVPs) displaying the heterologous peptide. Purified CVPs showed enhanced antimicrobial activity against the above-mentioned plant pathogens and human pathogens such as Staphylococcus aureus and Candida albicans. Moreover, in vivo assays designed to challenge KP-expressing plants (as CVPs) with Pseudomonas syringae pv. tabaci showed enhanced resistance to bacterial attack. The results indicate that the PVX-based display system is a high-yield, rapid, and efficient method to produce and evaluate antimicrobial peptides in plants, representing a milestone for the large-scale production of high-added-value peptides through molecular farming. Moreover, KP is a promising molecule to be stably engineered in plants to confer broad-spectrum resistance to phytopathogens. 相似文献
Traditional Knowledge and Useful Plant Richness in the Tehuacán–Cuicatlán Valley, Mexico. This study systematizes ethnobotanical information about the interactions between people and plants, ethnofloristic richness,
the relative importance of useful species richness in relation to general species richness, and plant management in the Tehuacán–Cuicatlán
Valley of central Mexico. The study recorded a total of 1,605 useful vascular plant species (61.2% of the total species richness
of the regional vascular flora), this being the region with the highest absolute richness of useful plant species in Mexico.
The null hypothesis that plant families with a higher number of useful species would be those having a higher general species
richness was analyzed through residuals method. The plant families richest in useful species were Poaceae, Asteraceae, Cactaceae,
Cyperaceae, Mimosaceae, and Solanaceae, most of which also have the highest general floristic richness. However, analyses
of use categories did not generally corroborate our hypothesis. About 1,335 of the useful species are wild, more than 500
species are submitted to some type of management (62 species are tolerated, 34 protected, 50 enhanced, and 358 cultivated),
but only a few have been studied to document their process of domestication. This information can be useful for developing
regional strategies of sustainable management of plant resources. 相似文献
Oligoribonucleotides containing a 5'-phosphorothiolate linkage have provided effective tools to study the mechanisms of RNA catalysis, allowing resolution of kinetic ambiguity associated with mechanistic dissection and providing a strategy to establish linkage between catalysis and specific functional groups. However, challenges associated with their synthesis have limited wider application of these modified nucleic acids. Here, we describe a general semisynthetic strategy to obtain these oligoribonucleotides reliably and relatively efficiently. The approach begins with the chemical synthesis of an RNA dinucleotide containing the 5'-phosphorothiolate linkage, with the adjacent 2'-hydroxyl group protected as the photolabile 2'-O-o-nitrobenzyl or 2'-O-α-methyl-o-nitrobenzyl derivative. Enzymatic ligation of the 2'-protected dinucleotide to transcribed or chemically synthesized 5' and 3' flanking RNAs yields the full-length oligoribonucleotide. The photolabile protecting group increases the chemical stability of these highly activated oligoribonucleotides during synthesis and long-term storage but is easily removed with UV irradiation under neutral conditions, allowing immediate use of the modified RNA in biochemical experiments. 相似文献
To identify predictive factors for 6 and 12-months mortality after discharge from a geriatric acute care unit, and from these, derive a mortality-risk index.
Methods and analysis
Prospective cohort study will be conducted on patients over 70 years-old admitted to a geriatric acute care unit and survived to hospital discharge. The main outcome measure will be mortality at 6 months and 12 months after discharge. Independent variables include sociodemographics, functional status, comorbidities, and clinical and laboratory characteristics. Risk factors associated with mortality will be constructed using multivariate logistic regression models. To build the mortality index, points will be assigned to each risk factor by dividing each beta coefficient in the logistic model by the lowest beta coefficient. A score will be assigned to each subject by adding up the points for each risk factor present in the model. The predictive accuracy of the model will be determined by comparing the predicted versus observed mortality in the study population and calculating the area under the ROC curves in both populations.
Conclusions
The risk-mortality index developed would allow an easy estimate to be made of individual risk of death at 6 months and 12 months after discharge from a geriatric acute care unit, with the purpose of establishing care plans and individualising treatment, according to real objectives. 相似文献
After chloroform fumigating an arable soil, the relative abundance of phylotypes belonging to only two phyla (Actinobacteria and Firmicutes) and two orders [Actinomycetales and Bacillales (mostly Bacillus)] increased in a subsequent aerobic incubation, while it decreased for a wide range of bacterial groups. It remained to be seen if similar bacterial groups were affected when an extreme alkaline saline soil was fumigated. Soil with electrolytic conductivity between 139 and 157 dS m?1, and pH 10.0 and 10.3 was fumigated and the bacterial community structure determined after 0, 1, 5 and 10 days by analysis of the 16S rRNA gene, while an unfumigated soil served as control. The relative abundance of the Firmicutes increased in the fumigated soil (52.8 %) compared to the unfumigated soil (34.2 %), while that of the Bacteroidetes decreased from 16.2 % in the unfumigated soil to 8.8 % in the fumigated soil. Fumigation increased the relative abundance of the genus Bacillus from 14.7 % in the unfumigated soil to 25.7 %. It was found that phylotypes belonging to the Firmicutes, mostly of the genus Bacillus, were dominant in colonizing the fumigated alkaline saline as found in the arable soil, while the relative abundance of a wide range of bacterial groups decreased. 相似文献