2,936 research outputs found
Sea turtle conservation: genetics and genomics for a better management
[eng] Conservation actions aim to preserve and recover animal and plant species using in-situ or ex- situ strategies. The first, aims to protect and sustain populations in their natural habitat, the second are implemented when local populations are extinct or are about to be. Conservation genetics can provide important insights into the dynamics of endangered populations facilitating their management. This thesis uses traditional markers and new generation sequencing to improve conservation management of the loggerhead (Caretta caretta) and the green turtle (Chelonia mydas). In the first 2 chapters we used microsatellites and mtDNA to assess the outcome of a reintroduction program of green turtles in the Cayman Islands and the status of the reintroduced wild population. We found that 90% of adult wild females and 80% of wild F1 hatchlings were related to the captive population, proving the program successful. This relatedness did affect negatively the fitness of the wild population. Moreover, we found that after only one generation, genetic differentiation between the populations was significant. Our results suggest that assisted colonisation is a viable solution to the global decline of biodiversity. The third chapter explores the potential of 2b-RAD methodology in the field of non-model species population genomics and provides guidelines to optimise protocol and decision making using 2b-RAD. We discovered that, given the big genome size of the loggerhead turtle, a selective-base ligation should be used to obtain an overall depth of coverage of 20x and make the study cost-effective. The fourth chapter studies the population structure and local adaptation of 9 Eastern Mediterranean loggerhead turtle rookeries using 2b- RAD genomic sequencing. We found a high level of population structure and no overlapping among rookeries. Bayesian clustering indicated our individuals to be grouped in nine genetic clusters, which correspond to the distribution found in the PCoA. We found that atmospheric temperature and geographic location of the rookery have a significant impact on population structure, as outlier loci were found associated with these predictors. These results aim to use fine scale genetic information of the Eastern Mediterranean Sea to inform and improve conservation management of loggerhead turtle rookeries
Balloon Aortic Valvuloplasty in the Transcatheter Aortic Valve Replacement Era: A "Die-Hard" Procedure
Percutaneous balloon aortic valvotomy (also known as balloon aortic valvuloplasty [BAV]) was first described in 1984 by Lababidi and Neuhaus1 and was reported for the treatment of congenital aortic..
"The child and the toy: an important relationship"
Investigating the importance of toy in child development from a functional, psycho-social and social viewpoint is the purpose of this paper. It has been noticed that through toy, more than through any other activity, the child learns to manipulate and control his objects. He deals with psychological problems when he lives over through toys the problems he has been « faced with in reality, and learns about social relations when he realizes that he must adjust himself to others if he wants to share his toys. There is a consensus that toy is a means of preparing a child for future occupations. This approach is shown through Cross-Cultural Analysis of games and the Conflict of Enculturement within social aspects of games and pla
Fungal diseases on tomato plant under greenhouse condition
The cultivation of crops in the greenhouse is the most intensive form of horticultural production. Greenhouse climatic conditions provide an ideal condition for the development of many foliar, stem and soil-borne plant diseases. Diseases are a major limiting factor for vegetable that cause serious yield reduction leading to severe economic losses. Fungi enter plants through natural openings such as stomata and through wounds caused by pruning, harvesting, hail, insects, other diseases, and mechanical damage. This chapter provides an overview of the most important diseases of tomato plants. Some of the diseases that will cover in this chapter are the follow: Early blight late, Septoria leaf spot, Late blight, Fusarium wilt, Verticillium wilt, Anthracnose, Buckeye rot, and Southern blight. For each disease, main symptoms and disease development are described. This review is based on combined information derived from available literature and expertise knowledge.
DOI: http://dx.doi.org/10.5281/zenodo.101116
A transformation perspective on marginal and conditional models
Clustered observations are ubiquitous in controlled and observational studies and arise naturally in multicenter trials or longitudinal surveys. We present a novel model for the analysis of clustered observations where the marginal distributions are described by a linear transformation model and the correlations by a joint multivariate normal distribution. The joint model provides an analytic formula for the marginal distribution. Owing to the richness of transformation models, the techniques are applicable to any type of response variable, including bounded, skewed, binary, ordinal, or survival responses. We demonstrate how the common normal assumption for reaction times can be relaxed in the sleep deprivation benchmark data set and report marginal odds ratios for the notoriously difficult toe nail data. We furthermore discuss the analysis of two clinical trials aiming at the estimation of marginal treatment effects. In the first trial, pain was repeatedly assessed on a bounded visual analog scale and marginal proportional-odds models are presented. The second trial reported disease-free survival in rectal cancer patients, where the marginal hazard ratio from Weibull and Cox models is of special interest. An empirical evaluation compares the performance of the novel approach to general estimation equations for binary responses and to conditional mixed-effects models for continuous responses. An implementation is available in the tram add-on package to the system and was benchmarked against established models in the literature
Treatment conditions and biochemical processes influencing seed priming effectiveness
A review of the scientific literature indicates osmotic priming (osmopriming) as the principal method of seed priming and polyethylene glycol (PEG) as the principal osmotic agent. An analysis of the available data across experiments carried out with different species under varying conditions showed an average 11% increase in percent germination and 36% shorter mean germination time (MGT) in primed vs. unprimed seeds. Moreover, in primed seeds MGT was less dependent on temperature, which is consistent with the effects expected from the treatment. Priming effects are mainly influenced by osmotic potential, temperature and time; major biochemical processes (repair of damaged DNA and RNA, preparation for cell division and increased antioxidant activity) are involved in treatment effects to an extent which is not fully ascertained in literature. A reduction of seed storage life is the major disadvantage of priming and the principal constraint to its diffusion, since dehydration to the initial moisture (drying-back) is needed to allow seed storage. Seed behaviour during drying-back, the role of the raffinose family oligosaccharides in cell membrane integrity and the expression of antioxidant enzymes in germinating seeds need to be further elucidated in a sufficient number of species, to promote a more reliable use of this technique
Hypervirulent antibiotic-resistantClostridium difficilein Europe
Recently, several Clostridium difficile outbreaks due to PCR ribotype 027, associated with increased disease severity and death, have been reported in North America and in several European countries. This strain is toxinA/toxinB-positive, contains the genes for binary toxin and has an 18 bp deletion and a frameshift mutation in the gene tcdC hypothesized to result in a deregulated expression of toxins A and B. These strains are high producers of toxins in vitro compared with other toxinotypes. Moreover, these strains show a high level of resistance to fluoroquinolones, possibly due to the presence of a transition mutation (C to T) in the gyr A, resulting in the amino acid substitution Th82->IIe. A 2 month prospective study was conducted in 38 hospitals in 14 different European countries to get an overview of the phenotypic and genotypic features of C. difficile isolates in 2005. In all, 411 isolates of C. difficile were obtained from diarrhoeic patients with suspected C. difficile -associated diarrhoea (CDAD); the prevalence of the 027 epidemic strain was 6.2%. All 027 strains were positive for binary toxin genes, had an 18 bp deletion in tcdC gene and were resistant to erythromycin and moxifloxacin. Patients infected with an 027 strain were likely to have a more severe disease (OR=2.52, 95% CI 0.92-6.85, p=0.04) and to have been more specifically treated by metronidazole or vancomycin (OR=7.23, CI 0.99-149, p=0.02). Ongoing epidemiological surveillance of CDAD cases with periodic characterization of the strains is needed to detect clustering of cases in time and space and to monitor the emergence of a specific hypervirulent clone. Key words: Clostridium difficile, toxins A and B, hypervirulence, C. difficile-associated diarrhoe
Support for the 2014 FIFA World Cup and the 2016 Olympic Games
The purposes of this research were (a) to explore and describe the relationships relative to the evaluation of the work of the organizers, expected legacy, and support for hosting the 2014 World Cup (WC) and the 2016 Olympic Games (OG); and (b) to compare Brazilians’ support for these two events. Social exchange theory (Blau & Scott, 1962) supported three structural models. Results indicated that Brazilians college students (n = 914) do not strongly support the country’s hosting of either the 2014 WC or the 2016 OG. They also do not believe the organizers adequately prepared the country to host the events, and, subsequently, do not have high positive legacy expectations. Mediated models indicated that higher perceptions of the work of the organizers in preparation for the sport mega-events predicted more positive legacy expectations of these events, and subsequently, larger intentions to support the events. Significant indirect effects indicated that a fully mediated model might be useful to describe relationships among intentions of support, expected legacy, and evaluations of the work of the organizers in preparing to host sport mega-events. Implications for theory and practice are discussed
Profondit? di mescolamento e valutazione del tempo di residenza delle acque lacustri
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