A comparison of different pre-lysis methods and extraction kits for recovery of Stretococcus agalacticae (Lancefield group B Streptococcus) DNA from whole blood

Sub-optimal recovery of bacterial DNA from whole blood samples can limit the sensitivity of molecular assays to detect pathogenic bacteria. We compared 3 different pre-lysis protocols (none, mechanical pre-lysis and achromopeptidasepre-lysis) and 5 commercially available DNA extraction platforms for direct detection of Group B Streptococcus (GBS) in spiked whole blood samples, without enrichment culture. DNA was extracted using the QIAamp Blood Mini kit (Qiagen), UCP Pathogen Mini kit (Qiagen), QuickGene DNA Whole Blood kit S (Fuji), Speed Xtract Nucleic Acid Kit 200 (Qiagen) and MagNA Pure Compact Nucleic Acid Isolation Kit I (Roche Diagnostics Corp). Mechanical pre-lysis increased yields of bacterial genomic DNA by 51.3 fold (95% confidence interval; 31.6–85.1, p < 0.001) and pre-lysis with achromopeptidase by 6.1 fold (95% CI; 4.2–8.9, p < 0.001), compared with no pre-lysis. Differences in yield dueto pre-lysis were 2–3 fold larger than differences in yield between extraction methods. Including a pre-lysis step can improve the limits of detection of GBS using PCR or other molecular methods without need for culture.

Real-Time Visual SLAM Using Pre - Existing Floor Lines as Landmarks and a Single Camera

SANTANA, André M.; SANTIAGO, Gutemberg S.; MEDEIROS, Adelardo A. D. Real-Time Visual SLAM Using Pre-Existing Floor Lines as Landmarks and a Single Camera. In: CONGRESSO BRASILEIRO DE AUTOMÁTICA, 2008, Juiz de Fora, MG. Anais... Juiz de Fora: CBA, 2008.

Security and Trust in Distributed Computation

We propose three research problems to explore the relations between trust and security in the setting of distributed computation. In the first problem, we study trust-based adversary detection in distributed consensus computation. The adversaries we consider behave arbitrarily disobeying the consensus protocol. We propose a trust-based consensus algorithm with local and global trust evaluations. The algorithm can be abstracted using a two-layer structure with the top layer running a trust-based consensus algorithm and the bottom layer as a subroutine executing a global trust update scheme. We utilize a set of pre-trusted nodes, headers, to propagate local trust opinions throughout the network. This two-layer framework is flexible in that it can be easily extensible to contain more complicated decision rules, and global trust schemes. The first problem assumes that normal nodes are homogeneous, i.e. it is guaranteed that a normal node always behaves as it is programmed. In the second and third problems however, we assume that nodes are heterogeneous, i.e, given a task, the probability that a node generates a correct answer varies from node to node. The adversaries considered in these two problems are workers from the open crowd who are either investing little efforts in the tasks assigned to them or intentionally give wrong answers to questions. In the second part of the thesis, we consider a typical crowdsourcing task that aggregates input from multiple workers as a problem in information fusion. To cope with the issue of noisy and sometimes malicious input from workers, trust is used to model workers' expertise. In a multi-domain knowledge learning task, however, using scalar-valued trust to model a worker's performance is not sufficient to reflect the worker's trustworthiness in each of the domains. To address this issue, we propose a probabilistic model to jointly infer multi-dimensional trust of workers, multi-domain properties of questions, and true labels of questions. Our model is very flexible and extensible to incorporate metadata associated with questions. To show that, we further propose two extended models, one of which handles input tasks with real-valued features and the other handles tasks with text features by incorporating topic models. Our models can effectively recover trust vectors of workers, which can be very useful in task assignment adaptive to workers' trust in the future. These results can be applied for fusion of information from multiple data sources like sensors, human input, machine learning results, or a hybrid of them. In the second subproblem, we address crowdsourcing with adversaries under logical constraints. We observe that questions are often not independent in real life applications. Instead, there are logical relations between them. Similarly, workers that provide answers are not independent of each other either. Answers given by workers with similar attributes tend to be correlated. Therefore, we propose a novel unified graphical model consisting of two layers. The top layer encodes domain knowledge which allows users to express logical relations using first-order logic rules and the bottom layer encodes a traditional crowdsourcing graphical model. Our model can be seen as a generalized probabilistic soft logic framework that encodes both logical relations and probabilistic dependencies. To solve the collective inference problem efficiently, we have devised a scalable joint inference algorithm based on the alternating direction method of multipliers. The third part of the thesis considers the problem of optimal assignment under budget constraints when workers are unreliable and sometimes malicious. In a real crowdsourcing market, each answer obtained from a worker incurs cost. The cost is associated with both the level of trustworthiness of workers and the difficulty of tasks. Typically, access to expert-level (more trustworthy) workers is more expensive than to average crowd and completion of a challenging task is more costly than a click-away question. In this problem, we address the problem of optimal assignment of heterogeneous tasks to workers of varying trust levels with budget constraints. Specifically, we design a trust-aware task allocation algorithm that takes as inputs the estimated trust of workers and pre-set budget, and outputs the optimal assignment of tasks to workers. We derive the bound of total error probability that relates to budget, trustworthiness of crowds, and costs of obtaining labels from crowds naturally. Higher budget, more trustworthy crowds, and less costly jobs result in a lower theoretical bound. Our allocation scheme does not depend on the specific design of the trust evaluation component. Therefore, it can be combined with generic trust evaluation algorithms.

Real-Time Visual SLAM Using Pre - Existing Floor Lines as Landmarks and a Single Camera

SANTANA, André M.; SANTIAGO, Gutemberg S.; MEDEIROS, Adelardo A. D. Real-Time Visual SLAM Using Pre-Existing Floor Lines as Landmarks and a Single Camera. In: CONGRESSO BRASILEIRO DE AUTOMÁTICA, 2008, Juiz de Fora, MG. Anais... Juiz de Fora: CBA, 2008.

Pre-colonial institutions and long-run development in Latin America

The present doctoral thesis studies the association between pre-colonial institutions and long-run development in Latin America. The thesis is organised as follows: Chapter 1 places the motivation of the thesis by underlying relevant contributions in the literature on long-run development. I then set out the main objective of the thesis, followed by a brief outline of it. In Chapter 2, I study the effects of pre-colonial institutions on present-day socioeconomic outcomes for Latin America. The main thesis of this chapter is that more advanced pre-colonial institutions relate to better socioeconomic outcomes today - principally, but not only, through their effects on the Amerindian population. I test such hypothesis with a dataset of 324 sub-national administrative units covering all mainland Latin American countries. The extensive range of controls covers factors such as climate, location, natural resources, colonial activities and pre-colonial characteristics - plus country fixed effects. Results strongly support the main thesis. In Chapter 3, I further analyse the association between pre-colonial institutions and present-day economic development in Latin America by using the historical ethnic homelands as my main unit of analysis. The main hypothesis is that ethnic homelands inhabited by more advanced ethnic groups -as measured by their levels of institutional complexity- relate to better economic development today. To track these long-run effects, I construct a new dataset by digitising historiographical maps allowing me to pinpoint the geospatial location of ethnic homelands as of the XVI century. As a result, 375 ethnic homelands are created. I then capture the levels of economic development at the ethnic homeland level by making use of alternative economic measures --satellite light density data. After controlling for country-specific characteristics and applying a large battery of geographical, locational, and historical factors, I found that the effects of pre-colonial institutions relate to a higher light density --as a proxy for economic activity- in ethnic homelands where more advanced ethnic groups lived. In Chapter 4, I explore a mechanism linking the persistence of pre-colonial institutions in Latin America over the long-run: Colonial and post-colonial strategies along with the ethnic political capacity worked in tandem allowing larger Amerindian groups to "support" the new political systems in ways that would benefit their respective ethnic groups as well as the population at large. This mechanism may have allowed the effects of pre-colonial institutions to influence socioeconomic development outcomes up to today. To shed lights on this mechanism, I combine the index of pre-colonial institutions prepared for the second chapter of the present thesis with individual-level survey data on people's attitudes. By controlling for key observable and unobservable country-specific characteristics, the main empirical results show that areas with a history of more advanced pre-colonial institutions increase the probability of individuals supporting present-day political institutions. Finally, in Chapter 5, I summarise the main findings of the thesis, and emphasise the key weaknesses of the study as well as potential avenues for future research.

Balancing the demands of two tasks: an investigation of cognitive-motor dual-tasking in relapsing remitting multiple sclerosis

Background: People with relapsing remitting MS (PwRRMS) suffer disproportionate decrements in gait under dual-task conditions, when walking and a cognitive task are combined. There has been much less investigation of the impact of cognitive demands on balance. This study investigated whether: (1) PwRRMS show disproportionate decrements in postural stability under dual-task conditions compared to healthy controls; (2) dual-task decrements are associated with everyday dual-tasking difficulties. In addition, the impact of mood, fatigue and disease severity on dual-tasking were also examined. Methods: 34 PwRRMS and 34 matched controls completed cognitive (digit span) and balance (movement of centre of pressure on a Biosway, on stable and unstable surfaces) tasks under single and dual-task conditions. Everyday dual-tasking was measured using the DTQ. Mood was measured by the HADS. Fatigue was measured via the MFIS. Results: No differences in age, gender, years of education, estimated pre-morbid IQ or baseline digit span between the groups. Compared to healthy controls, PwRRMS showed a significantly greater decrement in postural stability under dual-task conditions on an unstable surface (p=0.007), but not a stable surface (p=0.679). PwRRMS reported higher levels of everyday dual-tasking difficulties (p<0.001). Balance decrement scores were not correlated with everyday dual-tasking difficulties, or with fatigue. Stable surface balance decrement scores were significantly associated with levels of anxiety (rho=0.527, p=0.001) and depression (rho=0.451, p=0.007). Conclusion: RRMS causes difficulties with dual-tasking, impacting balance, particularly under challenging conditions, which may contribute to an increased risk of gait difficulties and falls. The striking relationship between anxiety/depression and dual-task decrement suggests that worry may be contributing to dual-task difficulties.

The Influence of Pre-Migration Factors and Post-Migration Climate of the Receiving Community on the Psychological Distress of Latino Immigrants

Over forty million foreign-born residents currently live in the United States. Latinos make up the largest population of immigrants living in the U.S. Previous research suggests that Latino immigrants often experience pre-migration stressors, such as traumatic experiences, political upheaval, and unplanned migration. These stressors may have a negative impact on immigrants’ post-migration mental health. Research also suggests that the post-migration climate of the receiving community may inform the connection between pre-migration experiences and post-migration mental health. The current study examined the relationship between Latino immigrants’ reasons for migration, migration planning, and pre-migration experience of political and/or interpersonal violence, and post-migration symptoms of psychological distress. In addition to examining the effect of these pre-migration factors, the current study also examined the community “climate” experienced by Latino immigrants post-migration by assessing the influence of three post-migration factors: 1) community support and engagement, 2) discrimination, and 3) employment. The study was a secondary analysis of data collected for the National Latino and Asian American Study, which focused on the mental health and service utilization of Latinos and Asian Americans. Participants included 1,629 Latino immigrants from across the United States. Results indicated that pre-migration experience of political and/or interpersonal trauma, post-migration experience of discrimination, and female sex were positively associated with psychological distress. Post-migration employment was negatively associated with psychological distress. In addition, discrimination modified the association between unplanned migration and psychological distress; the relationship between unplanned migration and psychological distress decreased for participants who reported more discrimination. Furthermore, employment modified the association between political and/or interpersonal trauma and psychological distress; the connection between trauma and psychological distress increased among those who reported having less employment. Recommendations for further research were presented. Policy and clinical practice implications were discussed, particularly given the current climate of high anti-immigrant sentiment and hostility in the U.S.

Curso online para a parte pral do Celpe-Bras : contribuições da avaliação de proficiência para o ensino-aprendizagem de PLE

Dissertação (mestrado)—Universidade de Brasília, Departamento de Línguas Estrangeiras e Tradução, Programa de Pós-Graduação em Linguística Aplicada, 2016.

Assessing Decision Making Skill in Complex and Dynamic Environments Using Representative and Simulated Tasks

Traditional decision making research has often focused on one's ability to choose from a set of prefixed options, ignoring the process by which decision makers generate courses of action (i.e., options) in-situ (Klein, 1993). In complex and dynamic domains, this option generation process is particularly critical to understanding how successful decisions are made (Zsambok & Klein, 1997). When generating response options for oneself to pursue (i.e., during the intervention-phase of decision making) previous research has supported quick and intuitive heuristics, such as the Take-The-First heuristic (TTF; Johnson & Raab, 2003). When generating predictive options for others in the environment (i.e., during the assessment-phase of decision making), previous research has supported the situational-model-building process described by Long Term Working Memory theory (LTWM; see Ward, Ericsson, & Williams, 2013). In the first three experiments, the claims of TTF and LTWM are tested during assessment- and intervention-phase tasks in soccer. To test what other environmental constraints may dictate the use of these cognitive mechanisms, the claims of these models are also tested in the presence and absence of time pressure. In addition to understanding the option generation process, it is important that researchers in complex and dynamic domains also develop tools that can be used by `real-world' professionals. For this reason, three more experiments were conducted to evaluate the effectiveness of a new online assessment of perceptual-cognitive skill in soccer. This test differentiated between skill groups and predicted performance on a previously established test and predicted option generation behavior. The test also outperformed domain-general cognitive tests, but not a domain-specific knowledge test when predicting skill group membership. Implications for theory and training, and future directions for the development of applied tools are discussed.

Genetic Breeding And Diversity Of The Genus Passiflora: Progress And Perspectives In Molecular And Genetic Studies.

Despite the ecological and economic importance of passion fruit (Passiflora spp.), molecular markers have only recently been utilized in genetic studies of this genus. In addition, both basic genetic researches related to population studies and pre-breeding programs of passion fruit remain scarce for most Passiflora species. Considering the number of Passiflora species and the increasing use of these species as a resource for ornamental, medicinal, and food purposes, the aims of this review are the following: (i) to present the current condition of the passion fruit crop; (ii) to quantify the applications and effects of using molecular markers in studies of Passiflora; (iii) to present the contributions of genetic engineering for passion fruit culture; and (iv) to discuss the progress and perspectives of this research. Thus, the present review aims to summarize and discuss the relationship between historical and current progress on the culture, breeding, and molecular genetics of passion fruit.

Whey And Soy Protein Supplements Changes Body Composition In Patients With Crohn's Disease Undergoing Azathioprine And Anti-tnf-alpha Therapy.

Crohn´s disease (CD) is a chronic transmural inflammation of the gastrointestinal tract of unknown cause. Malnutrition associated with active CD has been reduced although obesity has increased. Dietary strategies such as those with high-protein have been proposed to reduce body fat. This study compares the effects of two supplements on the nutritional status of CD patients. 68 CD patients were randomized in two groups: whey protein group (WP) and soy protein group (SP). Using bioimpedance analysis, anthropometry and albumin and pre-albumin dosages the nutritional status was measured before starting the intervention and after 8 and 16 weeks. The disease activity was determined by Crohn's Disease Activity Index and serum C-reactive protein dosage and dietary intake by 24h dietary recalls. Forty-one patients concluded the study and both supplements changed body composition similarly. Triceps skin fold thickness (p< 0.001) and body fat percentage (p=0.001) decreased, whereas mid-arm muscle circumference (p=0.004), corrected arm muscle area (p=0.005) and body lean percentage (p=0.001) increased. For Crohn's disease patients undergoing anti TNF-alpha and azatioprine therapies, supplementation with whey and soy proteins changes body composition through reduction of body fat and thus contributes to control inflammation.

KeaA, a Dictyostelium kelch-domain protein that regulates the response to stress and development

Background: The protein kinase YakA is responsible for the growth arrest and induction of developmental processes that occur upon starvation of Dictyostelium cells. yakA-cells are aggregation deficient, have a faster cell cycle and are hypersensitive to oxidative and nitrosoative stress. With the aim of isolating members of the YakA pathway, suppressors of the death induced by nitrosoative stress in the yakA-cells were identified. One of the suppressor mutations occurred in keaA, a gene identical to DG1106 and similar to Keap1 from mice and the Kelch protein from Drosophila, among others that contain Kelch domains. Results: A mutation in keaA suppresses the hypersensitivity to oxidative and nitrosoative stresses but not the faster growth phenotype of yakA-cells. The growth profile of keaA deficient cells indicates that this gene is necessary for growth. keaA deficient cells are more resistant to nitrosoative and oxidative stress and keaA is necessary for the production and detection of cAMP. A morphological analysis of keaA deficient cells during multicellular development indicated that, although the mutant is not absolutely deficient in aggregation, cells do not efficiently participate in the process. Gene expression analysis using cDNA microarrays of wild-type and keaA deficient cells indicated a role for KeaA in the regulation of the cell cycle and pre-starvation responses. Conclusions: KeaA is required for cAMP signaling following stress. Our studies indicate a role for kelch proteins in the signaling that regulates the cell cycle and development in response to changes in the environmental conditions.

Males still have limb asymmetries in multijoint movement tasks more than 2 years following anterior cruciate ligament reconstruction

More than 2 years after undergoing anterior cruciate ligament (ACL) reconstruction, women still present bilateral asymmetries during multijoint movement tasks. Given the well-known ACL-injury gender bias, the goal of this study was to investigate whether males also present such asymmetries more than 2 years after undergoing ACL reconstruction. This study involved 12 participants submitted to ACL reconstruction in the ACL group and 17 healthy participants in the control group. The mean postoperative period was 37 months. The participants executed bilateral countermovement jumps and load squat tasks. The kinematics and ground reaction forces on each lower limb and pelvis were recorded, and used to compute bilateral peak vertical ground reaction forces, peak knee and hip joint powers in the sagittal plane, and the ratio between these powers. For the jump task, the groups had the same performance in the jump height, but for the ACL group the peak knee joint power on the operated side was 13% lower than on the non-operated side (p = 0.02). For the squat task, the hip-knee joint power ratio on the operated side of the ACL group was 31% greater than on the non-operated side (p = 0.02). The ACL group presented a deficit in the operated knee that had its energy generation over time (joint power) partially substituted by the hip joint power of the same side. The fact that, even after more than 2 years following the ACL reconstruction and returning to regular activity, the ACL group still had neuromuscular asymmetries suggests a need for improvement in the ACL reconstruction surgery procedures and/or rehabilitation protocols.

Postural control during prolonged standing in persons with chronic low back pain

Prolonged standing has been associated with the onset of low back pain symptoms in working populations. So far, it is unknown how individuals with chronic low back pain (CLBP) behave during prolonged unconstrained standing (PS). The aim of the present study was to analyze the control of posture by subjects with CLBP during PS in comparison to matched healthy adults. The center of pressure (COP) position of 12 CLBP subjects and 12 matched healthy controls was recorded in prolonged standing (30 min) and quiet stance tasks (60 s) on a force plate. The number and amplitude of COP patterns, the root mean square (RMS), speed, and frequency of COP sway were analyzed. Statistical analyses showed that CLBP subjects produced less Postural changes in the antero-posterior direction with decreased postural sway during the prolonged standing task in comparison to the healthy group. Only CLBP subjects were influenced by the prolonged standing task, as demonstrated by their increased COP RMS, COP speed and COP frequency in the quiet standing trial after the prolonged standing task in comparison to the pre-PS trial. The present study provides additional evidence that individuals with CLBP might have altered sensory-motor function. Their inability to generate responses similar to those of healthy subjects during prolonged standing may contribute to CLBP persistence or an increase risk of recurrent back pain episodes. Moreover, quantification of postural changes during prolonged standing could be useful to identify CLBP subjects prone to postural control deficits. (C) 2008 Elsevier B.V. All rights reserved.