Wetlands Ecology and Management - Oil sands exploration activities across the Alberta boreal peatlands requires tree clearing and results in sites being left compressed and with altered understory... 相似文献
Protecting habitats for charismatic vertebrates can provide an ‘umbrella’ for less conspicuous organisms, especially when these are threatened by the same processes. However, such a conservation scheme is vulnerable to the extirpation of the focal species. We studied wider biodiversity values in long protected black stork (Ciconia nigra) nest sites, which were abandoned by the bird and thus legally subject to de-listing. In 20 abandoned nest sites in Estonia, we (i) mapped breeding birds within 600 m from the stork nest, and (ii) carried out time-limited surveys of lichens, polypore fungi, vascular plants and bryophytes in 2-ha plots. The breeding bird assemblages (64 species recorded) included 19 red-listed species, and showed no clear aggregation to the immediate surroundings of the stork nest. We recorded 740 plant and fungal species, of which 134 (18%) were of conservation concern (nationally protected, red-listed or extremely rare). Across the 2-ha plots, the numbers of the species of conservation concern varied more than three-fold (maximum 42 species), being affected notably by dead wood accumulation over time and presence of nemoral broad-leaved trees. The results demonstrate that many abandoned nest sites of the black stork have broader biodiversity significance, both due to the bird’s habitat requirements and the natural development during the protection. Expanding the umbrella function to sites abandoned by a focal species, but intact from anthropogenic degradation, can thus be a cost-effective conservation approach due to its low additional administrative burden. In most jurisdictions, the assessment procedure for such situations should be formalized, however.
Until now, four species of eye trematodes have been found in South America. Of them, Philophthalmus lucipetus (synonymized with Philophthalmus gralli) displays a broad host spectrum, with at least 30 bird species (prevalently large water birds), five mammal species and humans serving as definitive hosts, and with snails Fagotia (Microcolpia) acicularis, Amphimelania holandri, Melanopsis praemorsa and Melanoides tuberculata serving as intermediate hosts. When examining a total of 50 birds of ten species in the wetland of Pantanos de Villa, Lima, Peru in July 2011, eye trematodes were identified visually in the edematous conjunctival sac of 11 (48%) out of 23 resident many-colored rush tyrants Tachuris rubrigastra. Based on morphometric characteristics, the trematodes were identified as P. lucipetus. ITS2 and CO1 gene of the examined specimens combined showed a 99% similarity to an Iranian isolate of Philophthalmus sp. from the intermediate host Melanoides tuberculata, an invasive freshwater snail, suggesting that these two isolates represent the same species with a wide geographical range. Moreover, the prevalence of infection with the philophthalmid cercariae was 31% in 744 Melanoides tuberculata examined in Pantanos de Villa in 2010. It is evident that P. lucipetus occurs throughout the world as well as locally, including Eurasia and South America. Here we report this trematode for the first time in Peru, and we were the first to sequence any of the South American eye trematodes. Low host specificity of P. lucipetus and the invasive character of Melanoides tuberculata as a competent intermediate host suggest that eye trematodosis caused by P. lucipetus may emerge frequently in various parts of the world, especially in the tropics. Increase of the zoonotic potential of the P. lucipetus associated with this invasive snail spreading across the world is predictable and should be of interest for further research. 相似文献
Warao Amerindians, who inhabit the Orinoco Delta, are the second largest indigenous group in Venezuela. High Warao general mortality rates were mentioned in a limited study 21 years ago. However, there have been no comprehensive studies addressing child survival across the entire population.
Objectives
To determine the Child Survival-Index (CSI) (ratio: still-living children/total-live births) in the Warao population, the principal causes of childhood death and the socio-demographic factors associated with childhood deaths.
Methods
We conducted a cross-sectional epidemiological survey of 688 women from 97 communities in 7 different subregions of the Orinoco Delta. Data collected included socio-demographic characteristics and the reproductive history of each woman surveyed. The multidimensional poverty index (MPI) was used to classify the households as deprived across the three dimensions of the Human Development Index. Multivariable linear regression and Generalized Linear Model Procedures were used to identify socioeconomic and environmental characteristics statistically associated with the CSI.
Findings
The average CSI was 73.8% ±26. The two most common causes of death were gastroenteritis/diarrhea (63%) and acute respiratory tract Infection/pneumonia (18%). Deaths in children under five years accounted for 97.3% of childhood deaths, with 54% occurring in the neonatal period or first year of life. Most of the women (95.5%) were classified as multidimensionally poor. The general MPI in the sample was 0.56. CSI was negatively correlated with MPI, maternal age, residence in a traditional dwelling and profession of the head of household other than nurse or teacher.
Conclusions
The Warao have a low CSI which is correlated with MPI and maternal age. Infectious diseases are responsible for 85% of childhood deaths. The low socioeconomic development, lack of infrastructure and geographic and cultural isolation suggest that an integrated approach is urgently needed to improve the child survival and overall health of the Warao Amerindians. 相似文献
Biological Trace Element Research - Chromium (Cr) is a micromineral that is involved in the metabolism of carbohydrates, lipids, ammonia, and nucleic acids; thus, its supplementation can influence... 相似文献
Attention-deficit hyperactivity disorder (ADHD) is a developmental disorder characterized by symptoms of inattention, impulsivity and hyperactivity that adversely affect many aspects of life. Whereas the etiology of ADHD remains unknown, growing evidence indicates a genetic involvement in the development of this disorder. The brain circuits associated with ADHD are rich in monoamines, which are involved in the mechanism of action of psychostimulants and other medications used to treat this disorder. Dopamine (DA) is believed to play a major role in ADHD but other neurotransmitters are certainly also involved. Genetically modified mice have become an indispensable tool used to analyze the contribution of genetic factors in the pathogenesis of human disorders. Although rodent models cannot fully recapitulate complex human psychiatric disorders such as ADHD, transgenic mice offer an opportunity to directly investigate in vivo the specific roles of novel candidate genes identified in ADHD patients. Several knock-out and transgenic mouse models have been proposed as ADHD models, mostly based on targeting genes involved in DA transmission, including the gene encoding the dopamine transporter (DAT1). These mutant models provided an opportunity to evaluate the contribution of dopamine-related processes to brain pathology, to dissect the neuronal circuitry and molecular mechanisms involved in the antihyperkinetic action of psychostimulants and to evaluate novel treatments for ADHD. New transgenic models mouse models targeting other genes have recently been proposed for ADHD. Here, we discuss the recent advances and pitfalls in modeling ADHD endophenotypes in genetically altered animals. 相似文献