Nugget Formation and Mechanical Behaviour of Friction Stir Welds of Three Dissimilar Aluminum Alloys

The aim of this research was to investigate the influence of the properties of the base materials and welding speed on the morphology and mechanical behavior of the friction stir welds of three dissimilar aluminum alloys in a T-joint configuration. The base materials were the AA2017-T4, AA5083-H111, and AA6082-T6 alloys in 3 mm-thick sheets. The AA6082-T6 alloy was the stringer, and the other alloys were located either on the advancing or retreating sides of the skin. All the T-joint welds were produced with a constant tool rotation speed but with different welding speeds. The microstructures of the welds were analyzed using optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, and the electron backscatter diffraction technique. The mechanical properties were assessed according to micro-hardness, tensile, and fatigue testing. Good quality welds of the three dissimilar aluminum alloys could be achieved with friction stir welding, but a high ratio between the tool's rotational and traverse speeds was required. The welding speed influenced the weld morphology and fatigue strength. The positioning of the skin materials influenced the nugget morphology and the mechanical behavior of the joints. The joints in which the AA2017 alloy was positioned on the advancing side presented the best tensile properties and fatigue strength.info:eu-repo/semantics/publishedVersio

Individual investors repurchasing behavior : preference for stocks previously owned

In this paper we study the repurchasing behavior of individual investors and identify several characteristics (stock- and investor-specific) that affect the preference for repurchasing stocks previously owned. Using a unique database of 5,128 individual investors trading from August 1st, 2003 to July 31st, 2007, we find that investors prefer to repurchase stocks that are prior winners and those that dropped in price after being sold, in line with Strahilevitz, Odean and Barber (2011). We also find that the larger the prior gain, or the drop in stock price after the sell, the more likely is the investor to repurchase the same stock. Additionally, we find that (1) local stocks with negative market adjusted performance are more likely to be repurchased, and (2) less active, under-diversified, and poor performance investors are more likely to engage in such behavior. Overall, our results indicate that reference prices, prior stock returns, stock visibility, and investor performance and sophistication are determinants of the repurchasing behavior.COMPETE, QREN, FEDER, Fundação para a Ciência e a Tecnologia (FCT

A comparison of consultative psychiatric services in two Brazilian university hospitals using a standardized protocol for recording liaison consultations

O objetivo do presente estudo foi comparar pedidos de interconsulta psiquiátrica realizados para dois hospitais gerais universitários brasileiros e avaliar a aplicabilidade de um protocolo de registro de interconsulta psiquiátrica (PRISMe). Foi realizada análise dos pedidos de interconsulta, do PRISMe anexado a eles e o número total de pedidos de interconsulta incluídos na amostra foi 541 (438 pedidos de interconsulta do HCFMRP-USP e 103 pedidos de interconsulta do HU-UFSC). Observou-se maior freqüência de solicitação para pacientes do sexo feminino, caucasianos, entre 31 a 60 anos e casados. Os diagnósticos psiquiátricos mais freqüentes foram depressão, transtornos de adaptação e de personalidade. Os resultados estão de acordo com a literatura nacional e internacional e as diferenças encontradas podem ser atribuídas às diferenças na infra-estrutura das instituições e nos contextos sócio-econômicos nos quais estão inseridas. Achados do presente estudo demonstram a aplicabilidade do PRISMe e sugerem que podem facilitar a sistematização da obtenção de achados clínico-demográficos e a comparabilidade entre as diferenças.The objective of the present report was to compare consultative psychiatric services in two Brazilian university hospitals and to evaluate the applicability of a standardized protocol (PRISMe) for recording psychiatric liaison consultations. Analyses of psychiatric consultations and the attached protocol were performed. 541 consecutive liaison consultations were included in the final sample (438 consecutive consultations from the Federal university hospital in São Paulo and 103 from the Federal university hospital in Santa Catarina). In both hospitals, the majority of patients were female, married, white, and 31 to 60 years of age. Depression and adjustment and personality disorders were the most common psychiatric diagnoses, which could explain the higher referral of female patients. The results are consistent with the Brazilian and international literature, and the differences between the two hospitals could be related to both logistical differences between the consultative psychiatric services and the socioeconomic contexts. The findings confirm the applicability of the PRISMe and suggest that systematization of clinical and demographic information is important for future comparative studies.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)USP - Fundação de Apoio ao Ensino, Pesquisa e Assistência (FAEPA) do HCFMR

PLEKHG5 deficiency leads to an intermediate form of autosomal-recessive Charcot-Marie-Tooth disease

Charcot-Marie-Tooth disease (CMT) comprises a clinically and genetically heterogeneous group of peripheral neuropathies characterized by progressive distal muscle weakness and atrophy, foot deformities and distal sensory loss. Following the analysis of two consanguineous families affected by a medium to late-onset recessive form of intermediate CMT, we identified overlapping regions of homozygosity on chromosome 1p36 with a combined maximum LOD score of 5.4. Molecular investigation of the genes from this region allowed identification of two homozygous mutations in PLEKHG5 that produce premature stop codons and are predicted to result in functional null alleles. Analysis of Plekhg5 in the mouse revealed that this gene is expressed in neurons and glial cells of the peripheral nervous system, and that knockout mice display reduced nerve conduction velocities that are comparable with those of affected individuals from both families. Interestingly, a homozygous PLEKHG5 missense mutation was previously reported in a recessive form of severe childhood onset lower motor neuron disease (LMND) leading to loss of the ability to walk and need for respiratory assistance. Together, these observations indicate that different mutations in PLEKHG5 lead to clinically diverse outcomes (intermediate CMT or LMND) affecting the function of neurons and glial cell

Molecular diagnosis of Huntington disease in Portugal : implications for genetic counselling and clinical practice

Huntington disease (HD) is a eurodegenerative, autosomal dominant disorder of late-onset, caused by the expansion of a CAG repeat in the coding region of the gene. Ours is the reference laboratory for genetic testing in HD, in Portugal, since 1998; 90.1% of all 158 families known were identified for the first time, including patients with unusual presentation or without family history. A total of 338 genetic tests were performed: 234 for diagnosis, 96 for presymptomatic and four for prenatal testing (four were done for family studies). Most referring physicians were neurologists (90.6%); 82.8% of all clinical diagnosis were confirmed, while 83.1% of those sent for exclusion were in fact excluded. In presymptomatic testing, an excess of female subjects (59.4%) was again verified; 37.5% of the consultands were found to be carriers. None of the foetuses, in four prenatal tests, were mutation carriers. One juvenile case was inherited from her mother. Our patient population is very similar to others described so far, namely in terms of mean age at onset and (CAG)n distribution, except perhaps for a higher frequency of large normal (class 2) alleles (3.7%). We also identify cases posing particular problems for genetic counselling, such as, ‘homozygosity’ that can pose a serious ethical dilemma, carriers of large normal alleles, and ‘homoallelism’ for a normal gene, which will demand further procedures and may delay results in presymptomatic and prenatal testing

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost