Evolutionary processes in an environmental challenging site: the soda-lake Natron (Tanzania).

Lakes Natron and Magadi are neighbouring small soda localised in the Eastern Rift Valley, between Kenya and Tanzania, and are the remnants of the Paleolake Orolonga after a split that occurred around 9,000 years BP. These basins represent a really harsh environment, characterized by a complex geo-morphological structure, which may increase, by habitat fragmentation and isolation, the effects of evolutionary forces (like genetic drift and selection) on the native species and populations. These lakes harbour a small species flock of quite recent origin, the Alcolapia flock, endemic of this region and not found in any other place around the world. This flock is characterized by four different morphotypes: A. alcalicus, A. latilabris, A. ndalalani, endemic of Lake Natron, and A. grahami, found only in the Lake Magadi. With the aim to understand the evolutionary processes that are shaping genetic diversity of this species, we have analysed by means of molecular genetics tools (mtDNA and nuclear DNA markers), 310 specimens of Alcolapia collected from eight populations placed around the Lake Natron and from one population located in the north-east part of Lake Magadi. Phylogenetic analyses based on D-loop sequences of a subset of 69 Alcolapia have shown a monophyletic structure of the flock, as suggested by the more frequent haplotype (2lat) shared by all the morphotypes and corresponding to the Orolonga haplotype identified in previous studies (Seegers et al, 1999; Wilson et al., 2000 and 2004). Besides, the main starburst radiation occurred in Lake Natron Alcolapia, which evolved in relatively recent times

Evolutionary processes in an environmental challenging site: the soda-lake Natron (Tanzania).

Lakes Natron and Magadi are neighbouring small soda localised in the Eastern Rift Valley, between Kenya and Tanzania, and are the remnants of the Paleolake Orolonga after a split that occurred around 9,000 years BP. These basins represent a really harsh environment, characterized by a complex geo-morphological structure, which may increase, by habitat fragmentation and isolation, the effects of evolutionary forces (like genetic drift and selection) on the native species and populations. These lakes harbour a small species flock of quite recent origin, the Alcolapia flock, endemic of this region and not found in any other place around the world. This flock is characterized by four different morphotypes: A. alcalicus, A. latilabris, A. ndalalani, endemic of Lake Natron, and A. grahami, found only in the Lake Magadi. With the aim to understand the evolutionary processes that are shaping genetic diversity of this species, we have analysed by means of molecular genetics tools (mtDNA and nuclear DNA markers), 310 specimens of Alcolapia collected from eight populations placed around the Lake Natron and from one population located in the north-east part of Lake Magadi. Phylogenetic analyses based on D-loop sequences of a subset of 69 Alcolapia have shown a monophyletic structure of the flock, as suggested by the more frequent haplotype (2lat) shared by all the morphotypes and corresponding to the Orolonga haplotype identified in previous studies (Seegers et al, 1999; Wilson et al., 2000 and 2004). Besides, the main starburst radiation occurred in Lake Natron Alcolapia, which evolved in relatively recent times

The future of cross-boarder payments: a look into ripple's distributed ledger technology

After stirring the interest of the financial industry in 2017, Distributed Ledger Technology (DLT) is poised to become one of the fastest growing technologies in 2018 and beyond. This thesis aims to increase comprehension of the benefits associated with distributed transaction processing and attempts to evaluate whether Ripple’s solution has the required features to modernize the current cross-boarder payment infrastructure. Because Ripple’s DLT is currently going through the implementation and testing phase an assessment based on actual usage was not feasible, yet this research found the technology well equipped to become the standard for interbank funds transfer. It also points out the necessity for a comprehensive regulatory framework, which at present is lagging behind, that responds to DLTs uncommon features

Unsupervised feature learning using self-organizing maps.

In recent years a great amount of research has focused on algorithms that learn features from unlabeled data. These approaches are known as feature learning or deep learning methods and have been successfully applied to classify scene images and recognize with high precision handwritten characters. In this thesis we show that a feature learning approach can be used to segment complex textures, a problem for a long time addressed proposing a large amount of handcrafted descriptors and local optimization strategies. We employ the SOM neural network for its ability to natively provide a set of topologically ordered features. These features allow us to obtain a highly accurate local description, even in areas characterized by a transition from one texture to another. We also show that a single feature learning unit can be combined with others in order to significantly improve the quality of the texture description and, consequently, reduce the segmentation errors. The results obtained prove that the proposed segmentation method is valid and provides a real alternative to other state-of-the-art methods. Since the proposed framework is simple, we easily combined it with a pyramidal histogram encoding and a SVM supervised network in order to classify scene images. We show that the important topological ordering property, inherited from the SOM network, allow us to resize the feature set, obtained during the initial unsupervised learning, avoiding an unpredictable performance loss. Moreover, the results on the standard Caltech-101 dataset prove a significant improvement on some state-of-the-art computer vision methods, designed specifically for image classification

Causal Analysis of a National Study of Sales Personnel Turnover Functionality

A causal model of the antecedents of turnover functionality was developed and tested in a national field study of sales representatives from a Fortune 50 company. Turnover functionality was defined in terms of the difference between the performance levels of leavers and stayers in the host organization. Questionnaire data were collected from 1,732 salespeople, and it was predicted that the hypothesized model would be confirmed by the obtained data. Several forms of supporting evidence for the model were obtained. First, the hypothesized model provided a better, more parsimonious fit to the obtained data than did two plausible alternative models. Second, fit indices indicated acceptable overall fit for the hypothesized model. Third, 10 of 12 hypothesized paths in the model were supported. Fourth, exploratory analyses failed to improve upon the overall model fit. However, the model accounted for little variance in turnover functionality. Several potential explanations for these findings are explored, including the need for future research in this area to reconsider the manner in which turnover functionality is operationalized

The two isoforms of the mouse somatostatin receptor (mSSTR2A and mSSTR2B) differ m coupling efficiency to adenylate cyclase and in agonist-induced receptor desensitization

AbstractThe somatostatin receptor 2 (mSSTR2) is alternatively spliced into two isoforms (mSSTR2A and mSSTR2B) which differ at the C-terminus. Both receptors bind somatostatin peptides with a similar high affinity when stably expressed in CHO-K1 cells. However, the spliced form (mSSTR2B) mediates a more efficient inhibition of adenylate cyclase and is much more resistant to agonist-induced reduction of binding than the longer form (mSSTR2A). These findings indicate that alternative splicing may be a physiological mechanism to modulate receptor desensitization and G-protein coupling of mSSTR2

Les forêts et les montagnes vaudoises

L’incultum vaudois, soit ses régions non cultivées, a toujours été considéré comme marginal, lié à une économie pastorale et présentant des productions artisanales ponctuelles. La découverte de vestiges liés à une exploitation importante du territoire en vue de la production de produits comme fer, bois et surtout chaux, remet en question cette définition. À travers une approche pluridisciplinaire, nous nous proposons de rouvrir le débat sur le rôle de ces territoires marginaux au niveau du Canton et des communautés locales.Vaud incultum—uncultivated land—has traditionally being considered marginal, characterized by a pastoral economy, and by some isolated artisanal productions. This assumption is called into question by the discovery of evidence of an important exploitation of the territory, aimed at the production of products such as iron, wood, and especially lime. By applying an interdisciplinary approach, we propose to open again the debate on the role of these marginal regions at the cantonal and local community levels

Educa??o do Campo no Vale do Jequitinhonha: um olhar sobre o PROCAMPO

Data de aprova??o ausente.O presente trabalho teve por objetivo realizar uma an?lise explorat?ria a respeito do processo de constru??o do Curso de Licenciatura em Educa??o do Campo da Universidade Federal dos Vales do Jequitinhonha, o PROCAMPO/LEC, relacionado ao contexto de constru??o das lutas e pol?ticas p?blicas em torno da Educa??o do Campo no Brasil, em Minas Gerais e mais especificamente no Vale do Jequitinhonha. Para tanto foi utilizado o estudo de caso, com pesquisa qualitativa atrav?s de revis?o bibliogr?fica, centrada nas mobiliza??es sociais em torno de uma perspectiva de educa??o camponesa e a resposta do Estado a essas demandas, bem como an?lise documental dos registros do PROCAMPO, e ainda em entrevistas semiestruturadas com sujeitos envolvidos em diferentes etapas de constru??o do PROCAMPO na UFVJM, a saber: representantes da administra??o da UFVJM e do curso, professor volunt?rio, egressos do curso, e representante da Secretaria de Estado da Educa??o de Minas Gerais. O que se observou neste estudo foi a desconex?o entre as propostas elaboradas pelos movimentos sociais em rela??o ? educa??o do campo quando estas se tornam pol?ticas p?blicas. A rigidez das normas estatais, o pouco entendimento dos gestores sobre as demandas e propostas dos movimentos, al?m de diverg?ncias pol?ticas provocaram descontinuidades entre as experi?ncias educacionais constru?das pelos movimentos e as pol?ticas p?blicas implementadas a partir de uma orienta??o pela Educa??o do Campo. Tais descontinuidades foram observadas n?o s? no ?mbito geral, mas tamb?m no PROCAMPO da UFVJM e indicam pontos nodais que demandam maior abertura para o di?logo entre estado e sociedade. Tamb?m ficou expl?cita a fragilidade das pol?ticas p?blicas de educa??o do campo, muitas vezes secundarizadas at? mesmo pelas institui??es que as acolhem. E por consequ?ncia, trouxe ? tona a grande energia dispendida pelas organiza??es camponesas na manuten??o dessas pol?ticas, mesmo com cr?ticas a seu formato e forma de implanta??o.Disserta??o (Mestrado Profissional) ? Programa de P?s-Gradua??o em Ci?ncias Humanas, Universidade Federal dos Vales do Jequitinhonha e Mucuri, [2016].The present study aimed to carry out an exploratory analysis about the construction process of the Rural Education Licentiate Course at the Federal University of Jequitinhonha (PROCAMPO / LEC), related to the context of social movements claims for Rural Education public policies in Brazil, Minas Gerais, and more specifically in the Jequitinhonha Valley. For this case of study qualitative research was used through literature review focused on social mobilization for rural education and the State's response to these demands. Along with documentary analysis of PROCAMPO records, semi-structured interviews with individuals involved in different stages of construction in UFVJM PROCAMPO - two ex-member of the administration of UFVJM and PROCAMPO, a volunteer teacher, two course graduates, and a member of the State Department of Education of Minas Gerais - were also used. In this study it was possible to observe the disconnection between the social movements proposals and its respective public policies. Some of the reasons were rigid state standards, the limited understanding of the managers on the demands and proposals of the social movements, and political differences between involved parts. Such discontinuities were observed not only in general context but also in the UFVJM PROCAMPO and indicate nodal points that require more openness for dialogue between state and society. The fragility of public policy for rural education was also explicit, often backgrounded even by the same institutions hosting them. As a result, it was brought to light the great energy expended by peasant organizations in maintaining these policies, despite criticism of its format and implementation form