bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constrained model predictive control for mobile robotic manipulators
Authors: Buizza Avanzini Giovanni , Zanchettin Andrea Maria , Rocco Paolo 
Published: April 2017

SUMMARYThis paper discusses the application of a constraint-based model predictive control (MPC) to mobile manipulation tracking problems. The problem has been formulated so as to guarantee offset-free tracking of piecewise constant references, with convergence and recursive feasibility guarantees. Since MPC inputs are recomputed at every control iteration, it is possible to deal with dynamic and unknown scenarios. A number of motion constraints can also be easily included: Acceleration, velocity and position constraints have been enforced, together with collision avoidance constraints for the mobile base and the arm and field-of-view constraints. Such constraints have been extended over the prediction horizon maintaining a linear-quadratic formulation of the problem. Navigation performance has been improved by devising an online algorithm that includes an additional goal to the problem, derived from the classical vortex field approach. Experimental validation shows the applicability of the proposed approach.
Collision avoidance method for multi-operator multi-robot teleoperation system
Authors: García S. E. , Slawiñski E. , Mut V. , Penizzotto F. 
Published: April 2017

SUMMARYThis paper proposes a collision avoidance method for the teleoperation of multiple non-holonomic mobile robots from multiple users. Each human operator drives a mobile robot, where each one performs an independent task in a common workspace. To avoid collisions, the proposed method only acts on the speed of the mobile robots; therefore, the human operator can freely drive the robot over the path he chooses to. The developed analysis allows us to assure that a solution is always achieved. Finally, the results of the experiments are shown, in order to test the performance of the proposed control scheme.
Assessing visitors’ preferences for ecosystem features in a desert biodiversity hotspot
Authors: CERDA CLAUDIA , FUENTES JUAN PABLO , DE LA MAZA CARMEN LUZ , LOUIT CARLA , ARAOS ANA 
Published: April 2017

SUMMARYWe estimated visitors’ willingness to pay (WTP) for a variety of environmental attributes in a protected area of the Atacama Desert, a biodiversity hotspot in northern Chile. By using a choice experiment, WTP was estimated for the protection of the following attributes: animals (mammals, amphibians, reptiles and birds), pollinating insects, plants (cacti and woody shrubs), soil quality and pristine landscapes. Visitors placed economic value on all of the attributes. The marginal mean WTP/visitor for the single levels of variation in the attributes ranged from US$4 (for supporting research on foxes) to US$26 (for maintaining soil quality) per visitor per month. These results can contribute to deciding which attributes are likely to be successful at raising funds for conservation. Our approach may be relevant to protected areas of the world with high conservation values, little funding and a lack of large, charismatic species.
Transitional Justice + Cyberjustice = Justice2?
Authors: KASTNER PHILIPP 
Published: April 2017

AbstractThe increased use of information and communication technologies arguably represents important opportunities for the field of transitional justice, notably with respect to the optimization of existing mechanisms and the development of new ones. This article focuses on state-based and typically very formal mechanisms, namely international, internationalized and national criminal tribunals as well as truth and reconciliation commissions. These institutions often apply and engage with international law and operate with the involvement or under the close scrutiny of the international community. Moreover, they can be expected to be the first ones to embrace insights from the field of cyberjustice to a significant extent.Enhancing access to and participation in such mechanisms, rendering them more cost-efficient and facilitating information-sharing would correspond to generally accepted norms relating to both international human rights and justice. However, cyberjustice initiatives may also entrench an already common ‘toolkit approach’ in the field of transitional justice. This article builds on recent critiques of the dominant legalistic and normatively driven transitional justice paradigm and argues that transitional justice + cyberjustice hence risks furthering a technocratic top-down approach that unduly limits creative solutions. By adopting a critical legal-pluralistic approach that conceives individuals as law-creative actors and that is cognizant of the close relationship between means and ends, the article imagines ways of benefiting from the promises of transitional justice + cyberjustice.
Externalizing and internalizing pathways to Mexican American adolescents’ risk taking
Authors: Gonzales Nancy A. , Liu Yu , Jensen Michaeline , Tein Jenn Yun , White Rebecca M. B. , Deardorff Julianna 
Published: April 2017

AbstractThis study used four waves of data from a longitudinal study of 749 Mexican origin youths to test a developmental cascades model linking contextual adversity in the family and peer domains in late childhood to a sequence of unfolding processes hypothesized to predict problem substance use and risky sexual activity (greater number of sex partners) in late adolescence. Externalizing and internalizing problems were tested as divergent pathways, with youth-reported and mother-reported symptoms examined in separate models. Youth gender, nativity, and cultural orientation were tested as moderators. Family risk, peer social rejection, and their interaction were prospectively related to externalizing symptoms and deviant peer involvement, although family risk showed stronger effects on parent-reported externalizing and peer social rejection showed stronger effects on youth-reported externalizing. Externalizing symptoms and deviant peers were related, in turn, to risk taking in late adolescence, including problem alcohol–substance use and number of sexual partners. Peer social rejection predicted youth-reported internalizing symptoms, and internalizing was related, in turn, to problem alcohol and substance use in late adolescence. Tests of moderation showed some of these developmental cascades were stronger for adolescents who were female, less oriented to mainstream cultural values, and more oriented to Mexican American cultural values.
Methodological Challenges in Studies Comparing Prehospital Advanced Life Support with Basic Life Support
Authors: Li Timmy , Jones Courtney M. C. , Shah Manish N. , Cushman Jeremy T. , Jusko Todd A. 
Published: April 2017

AbstractDetermining the most appropriate level of care for patients in the prehospital setting during medical emergencies is essential. A large body of literature suggests that, compared with Basic Life Support (BLS) care, Advanced Life Support (ALS) care is not associated with increased patient survival or decreased mortality. The purpose of this special report is to synthesize the literature to identify common study design and analytic challenges in research studies that examine the effect of ALS, compared to BLS, on patient outcomes. The challenges discussed in this report include: (1) choice of outcome measure; (2) logistic regression modeling of common outcomes; (3) baseline differences between study groups (confounding); (4) inappropriate statistical adjustment; and (5) inclusion of patients who are no longer at risk for the outcome. These challenges may affect the results of studies, and thus, conclusions of studies regarding the effect of level of prehospital care on patient outcomes should require cautious interpretation. Specific alternatives for avoiding these challenges are presented.LiT,JonesCMC,ShahMN,CushmanJT,JuskoTA.Methodological challenges in studies comparing prehospital Advanced Life Support with Basic Life Support.Prehosp Disaster Med.2017;32(4):444–450.
Mild Cognitive Impairment Subtypes in a Cohort of Elderly Essential Tremor Cases
Authors: Collins Kathleen , Rohl Brittany , Morgan Sarah , Huey Edward D. , Louis Elan D. , Cosentino Stephanie 
Published: April 2017

AbstractObjectivesIndividuals with essential tremor (ET) exhibit a range of cognitive deficits generally conceptualized as “dysexecutive” or “fronto-subcortical,” and thought to reflect disrupted cortico-cerebellar networks. In light of emerging evidence that ET increases risk for Alzheimer’s disease (AD), it is critical to more closely examine the nature of specific cognitive deficits in ET, with particular attention to amnestic deficits that may signal early AD.MethodsWe performed a cross-sectional analysis of baseline data from 128 ET cases (age 80.4±9.5 years) enrolled in a longitudinal, clinical-pathological study. Cases underwent a comprehensive battery of motor-free neuropsychological tests and a functional assessment to inform clinical diagnoses of normal cognition (ET-NC), mild cognitive impairment (MCI) (ET-MCI), or dementia (ET-D). ET-MCI was subdivided into subtypes including: amnestic single-domain (a-MCI), amnestic multi-domain (a-MCI+), non-amnestic single-domain (na-MCI), or non-amnestic multi-domain (na-MCI+).ResultsNinety-one (71.1%) cases were ET-NC, 24 (18.8%) were ET-MCI, and 13 (10.2%) were ET-D. Within MCI, the a-MCI+ subtype was the most common (13/24; 54.2%) followed by a-MCI (4/24; 16.7%), na-MCI+ (4/24; 16.7%), and na-MCI (3/24; 12.5%). Cases with amnestic MCI demonstrated lower recognition memoryZ-scores (−2.4±1.7) than non-amnestic groups (−0.9±1.2) (p=.042).ConclusionsAmnestic MCI, defined by impaired memory recall but associated with lower memory storage scores, was the most frequent MCI subtype in our study. Such impairment has not been explicitly discussed in the context of ET and may be an early hallmark of AD. Results have implications for the prognosis of specific cognitive deficits in ET. (JINS, 2017,23, 390–399)
The livelihood impacts of the Equitable Payments for Watershed Services (EPWS) Program in Morogoro, Tanzania
Authors: Kwayu Emmanuel J. , Paavola Jouni , Sallu Susannah M. 
Published: April 2017

AbstractResearch on PES programs in agro-ecosystems is recent and limited in developing countries. The authors use a multi-method, quasi-experimental impact evaluation approach to examine direct and indirect livelihood impacts of the Equitable Payments for Watershed Services (EPWS) program piloted in the Morogoro region in Tanzania. The evaluation is based on a survey of 116 program participants and 117 non-participants, 32 semi-structured interviews and 16 focus group discussions to complement the survey data. They find that, while the EPWS program incentives resulted in direct benefits, indirect benefits such as increased crop yields, higher land values, new employment opportunities, more knowledgeable farmers, improved leadership skills as well as increased trust, expanded internal and external networks and strengthened institutions were more important. The results clearly indicate the potential of PES schemes to generate win-win outcomes in agro-ecosystems, but they also call for attention to equity in the design of PES programs implemented on agro-ecosystems.
Segmentation and Quantitative Analysis of Apoptosis of Chinese Hamster Ovary Cells from Fluorescence Microscopy Images
Authors: Du Yuncheng , Budman Hector M. , Duever Thomas A. 
Published: April 2017

AbstractAccurate and fast quantitative analysis of living cells from fluorescence microscopy images is useful for evaluating experimental outcomes and cell culture protocols. An algorithm is developed in this work to automatically segment and distinguish apoptotic cells from normal cells. The algorithm involves three steps consisting of two segmentation steps and a classification step. The segmentation steps are: (i) a coarsesegmentation, combining a range filter with a marching square method, is used as a prefiltering step to provide the approximate positions of cells within a two-dimensional matrix used to store cells’ images and the count of the number of cells for a given image; and (ii) a fine segmentation step using the Active Contours Without Edges method is applied to the boundaries of cells identified in the coarse segmentation step. Although this basic two-step approach provides accurate edges when the cells in a given image are sparsely distributed, the occurrence of clusters of cells in high cell density samples requires further processing. Hence, a novel algorithm for clusters is developed to identify the edges of cells within clusters and to approximate their morphological features. Based on the segmentation results, a support vector machine classifier that uses three morphological features: the mean value of pixel intensities in the cellular regions, the variance of pixel intensities in the vicinity of cell boundaries, and the lengths of the boundaries, is developed for distinguishing apoptotic cells from normal cells. The algorithm is shown to be efficient in terms of computational time, quantitative analysis, and differentiation accuracy, as compared with the use of the active contours method without the proposed preliminary coarse segmentation step.
Contracting and gender equity in Tanzania: using a value chain approach to understand the role of gender in organic spice certification
Authors: Bullock Renee , Gyau Amos , Mithoefer Dagmar , Swisher Marilyn 
Published: April 2017

AbstractValue chain development (VCD) initiatives within the horticultural and organic sectors in Africa are promising strategies to improve smallholder welfare. Contracting institutional arrangements are a common feature of VCD initiatives and are increasing in number in sub-Saharan Africa as a way to source organic products from smallholder producers. The objective of this study is to better understand men and women's participation in spice producing households that sell under contract and in conventional market chains in the East Usambaras, Tanzania. We draw on New Institutional Economics, political economy and the value chain analysis framework to assess the potential role of contracting to promote gender equity among smallholder organic horticultural producers. We describe intra-household decision making over resources and marketing, access to benefits of contracting, and labor distribution between men and women in contracting and non-contracting households. We then extend the gender analysis to evaluate the role of gender in contracting and conventional value chains operating within the community and district. Using a cross-sectional research design and data collected through 13 focus group discussions, 54 personal interviews and 156 household questionnaires, we show that contracting reduces transaction costs in the chain compared with the conventional trade. However, norms in the wider political economic context give rise to gendered patterns of participation in both household and chain activities in contracting and non-contracting households. Our findings suggest that contracting does not provide significant opportunities for women in married households to participate and benefit based on limited participation in decision-making and access to trainings. Divorced women and widows gain access to contract employment opportunities to earn income. This study highlights the importance of understanding gender relations in the household and community to guide the development of gender equitable VCD initiatives and contracting approaches.
The Singaporean public beliefs about the causes of mental illness: results from a multi-ethnic population-based study
Authors: Pang S. , Subramaniam M. , Lee S. P. , Lau Y. W. , Abdin E. , Chua B. Y. , Picco L. , Vaingankar J. A. , Chong S. A. 
Published: April 2017

Aims.To identify the common causal beliefs of mental illness in a multi-ethnic Southeast Asian community and describe the sociodemographic associations to said beliefs. The factor structure to the causal beliefs scale is explored. The causal beliefs relating to five different mental illnesses (alcohol abuse, depression, obsessive-compulsive disorder (OCD), dementia and schizophrenia) and desire for social distance are also investigated.Methods.Data from 3006 participants from a nationwide vignette-based study on mental health literacy were analysed using factor analysis and multiple logistic regression to address the aims. Participants answered questions related to sociodemographic information, causal beliefs of mental illness and their desire for social distance towards those with mental illness.Results.Physical causes, psychosocial causes and personality causes were endorsed by the sample. Sociodemographic differences including ethnic, gender and age differences in causal beliefs were found in the sample. Differences in causal beliefs were shown across different mental illness vignettes though psychosocial causes was the most highly attributed cause across vignettes (endorsed by 97.9% of respondents), followed by personality causes (83.5%) and last, physical causes (37%). Physical causes were more likely to be endorsed for OCD, depression and schizophrenia. Psychosocial causes were less often endorsed for OCD. Personality causes were less endorsed for dementia but more associated with depression.Conclusions.The factor structure of the causal beliefs scale is not entirely the same as that found in previous research. Further research on the causal beliefs endorsed by Southeast Asian communities should be conducted to investigate other potential causes such as biogenetic factors and spiritual/supernatural causes. Mental health awareness campaigns should address causes of mental illness as a topic. Lay beliefs in the different causes must be acknowledged and it would be beneficial for the public to be informed of the causes of some of the most common mental illnesses in order to encourage help-seeking and treatment compliance.
Relationship between Leadership among Peers and Burnout in Sports Teams
Authors: Torrado Julio , Arce Constantino , Vales-Vázquez Ángel , Areces Alberto , Iglesias Gabriel , Valle Iván , Patiño Gabriel 
Published: April 2017

AbstractThis study has been conducted with the aim of ascertaining the relationship between peer leaders in sport teams and the levels of burnout experienced by their team-mates. A total of 219 Spanish athletes involved in football and basketball participated in the study. To measure leadership among peers, we employed the Sports Peer Leadership Scale, which comprises 24 items, grouped into 6 primary factors: empathy, influence on decision making, sports values, social support, training orientation and competition orientation. And to measure burnout, we employed the Athlete Burnout Questionnaire, which comprises 15 items which are indicators of physical and emotional exhaustion, devaluation and reduced sense of accomplishment among athletes. The results led to the conclusion that there is a statistically significant negative relationship between perceived leadership capacity and the levels of burnout experience by a team. The greater the level of leadership capacity perceived, the lower the levels of burnout will be. A multiple regression analysis with total burnout as dependent variable and social and task orientations of the leader as predictors showed standardized regression coefficients of –.241 (p = .010) and –.076 (p = .413), respectively for social and task orientation, being the effect size equal to .089.
Learning through ferroelectric domain dynamics in solid-state synapses
Authors: Boyn Sören , Grollier Julie , Lecerf Gwendal , Xu Bin , Locatelli Nicolas , Fusil Stéphane , Girod Stéphanie , Carrétéro Cécile , Garcia Karin , Xavier Stéphane , Tomas Jean , Bellaiche Laurent , Bibes Manuel , Barthélémy Agnès , Saïghi Sylvain , Garcia Vincent 
Published: April 2017

AbstractIn the brain, learning is achieved through the ability of synapses to reconfigure the strength by which they connect neurons (synaptic plasticity). In promising solid-state synapses called memristors, conductance can be finely tuned by voltage pulses and set to evolve according to a biological learning rule called spike-timing-dependent plasticity (STDP). Future neuromorphic architectures will comprise billions of such nanosynapses, which require a clear understanding of the physical mechanisms responsible for plasticity. Here we report on synapses based on ferroelectric tunnel junctions and show that STDP can be harnessed from inhomogeneous polarization switching. Through combined scanning probe imaging, electrical transport and atomic-scale molecular dynamics, we demonstrate that conductance variations can be modelled by the nucleation-dominated reversal of domains. Based on this physical model, our simulations show that arrays of ferroelectric nanosynapses can autonomously learn to recognize patterns in a predictable way, opening the path towards unsupervised learning in spiking neural networks.
Src family kinases Fyn and Lyn are constitutively activated and mediate plasmacytoid dendritic cell responses
Authors: Dallari S. , Macal M. , Loureiro M. E. , Jo Y. , Swanson L. , Hesser C. , Ghosh P. , Zuniga E. I. 
Published: April 2017

AbstractPlasmacytoid dendritic cells (pDC) are type I interferon-producing cells with critical functions in a number of human illnesses; however, their molecular regulation is incompletely understood. Here we show the role of Src family kinases (SFK) in mouse and human pDCs. pDCs express Fyn and Lyn and their activating residues are phosphorylated both before and after Toll-like receptor (TLR) stimulation. Fyn or Lyn genetic ablation as well as treatment with SFK inhibitors ablate pDC (but not conventional DC) responses bothin vitroandin vivo. Inhibition of SFK activity not only alters TLR-ligand localization and inhibits downstream signalling events, but, independent ofex-vivoTLR stimulation, also affects constitutive phosphorylation of BCAP, an adaptor protein bridging PI3K and TLR pathways. Our data identify Fyn and Lyn as important factors that promote pDC responses, describe the mechanisms involved and highlight a tonic SFK-mediated signalling that precedes pathogen encounter, raising the possibility that small molecules targeting SFKs could modulate pDC responses in human diseases.
Enzyme catalysed Pictet-Spengler formation of chiral 1,1’-disubstituted- and spiro-tetrahydroisoquinolines
Authors: Lichman Benjamin R. , Zhao Jianxiong , Hailes Helen C. , Ward John M. 
Published: April 2017

AbstractThe Pictet–Spengler reaction (PSR) involves the condensation and ring closure between a β-arylethylamine and a carbonyl compound. The combination of dopamine and ketones in a PSR leads to the formation of 1,1′-disubstituted tetrahydroisoquinolines (THIQs), structures that are challenging to synthesize and yet are present in a number of bioactive natural products and synthetic pharmaceuticals. Here we have discovered that norcoclaurine synthase fromThalictrum flavum(TfNCS) can catalyse the PSR between dopamine and unactivated ketones, thus facilitating the facile biocatalytic generation of 1,1′-disubstituted THIQs. Variants ofTfNCS showing improved conversions have been identified and used to synthesize novel chiral 1,1′-disubstituted and spiro-THIQs. Enzyme catalysed PSRs with unactivated ketones are unprecedented, and, furthermore, there are no equivalent stereoselective chemical methods for these transformations. This discovery advances the utility of enzymes for the generation of diverse THIQsin vitroandin vivo.