1,774 research outputs found
Arsonists or firefighters? Affectiveness in agile software development
In this paper, we present an analysis of more than 500K comments from open-source repositories of software systems developed using agile methodologies. Our aim is to empirically determine how developers interact with each other under certain psychological conditions generated by politeness, sentiment and emotion expressed within developers' comments. Developers involved in an open-source projects do not usually know each other; they mainly communicate through mailing lists, chat, and tools such as issue tracking systems. The way in which they communicate a ects the development process and the productivity of the people involved in the project. We evaluated politeness, sentiment and emotions of comments posted by agile developers and studied the communication ow to understand how they interacted in the presence
of impolite and negative comments (and vice versa). Our analysis shows that \ re ghters" prevail. When in presence of impolite or negative comments, the probability of the next comment being impolite or negative is 13% and 25%, respectively; ANGER however, has a probability of 40% of being followed by a further ANGER comment. The result could help managers take control the development phases of a system, since social
aspects can seriously a ect a developer's productivity. In a distributed agile environment this may have a particular resonance
Trial-by-Trial Changes in a Priori Informational Value of External Cues and Subjective Expectancies in Human Auditory Attention
Background: Preparatory activity based on a priori probabilities generated in previous trials and subjective expectancies would produce an attentional bias. However, preparation can be correct (valid) or incorrect (invalid) depending on the actual target stimulus. The alternation effect refers to the subjective expectancy that a target will not be repeated in the same position, causing RTs to increase if the target location is repeated. The present experiment, using the Posner’s central cue paradigm, tries to demonstrate that not only the credibility of the cue, but also the expectancy about the next position of the target are changedin a trial by trial basis. Sequences of trials were analyzed. Results: The results indicated an increase in RT benefits when sequences of two and three valid trials occurred. The analysis of errors indicated an increase in anticipatory behavior which grows as the number of valid trials is increased. On the other hand, there was also an RT benefit when a trial was preceded by trials in which the position of the target changed with respect to the current trial (alternation effect). Sequences of two alternations or two repetitions were faster than sequences of trials in which a pattern of repetition or alternation is broken. Conclusions: Taken together, these results suggest that in Posner’s central cue paradigm, and with regard to the anticipatory activity, the credibility of the external cue and of the endogenously anticipated patterns of target location are constantly updated. The results suggest that Bayesian rules are operating in the generation of anticipatory activity as
Museo Comunitario, propuesta de desarrollo ecoturístico para municipios del Estado de Oaxaca
El Estado de Oaxaca se encuentra dividido en ocho regiones geográficas las cuales comprenden 30 distritos, mismos que están formados por 570 municipios, las regiones son: la Costa, el Istmo, los Valles Centrales, la Cañada, la Mixteca, la Sierra Norte, Sierra Sur y el Papaloapan; cada uno de ellos tienen diversas costumbres y tradiciones, así como su tipo de gobierno.
Para Montero (2004:147) “el patrimonio tangible, que lleva a los sitios que son sagrados en alguna cultura, obra y producto hecha por el hombre, como lo son los museos, monumentos, lugares y localidades de arte o de carácter, sitios arqueológicos, etc. y el patrimonio que es intangible, remite a expresiones y fiestas tradicionales y de saberes-hacer del pasado y del presente”. Dentro de los municipios del estado de Oaxaca, se encuentra una variedad de patrimonios culturales tangibles e intangibles, por lo que este trabajo de investigación tiene como objetivo general: Proponer el diseño de museos comunitarios en municipios con características de subdesarrollo o marcadas desigualdades económicas, que permitan el desarrollo del mismo; generándose un progreso del ecoturismo.
El trabajo se divide en tres partes: la primera describe el área de estudio, la segunda, el estado del arte que permite comprender lo que es un museo comunitario, su importancia, así como sus características, y finalmente se desarrolla la propuesta. La metodología que se llevó a cabo es de gabinete, de consultas de trabajos realizados sobre el tema propuesto, por lo que la hipótesis que se esboza es la siguiente: Una estrategia de política pública del diseño de un museo comunitario permite el desarrollo local de municipios con marcadas desigualdades económicas.
No obstante, dentro de la definición e importancia del museo comunitario; es conveniente señalar la definición de “museo”. Para Rivière (1993:70), es una institución al servicio de la sociedad que selecciona, adquiere, conserva, comunica y sobre todo expone con fines de acrecentamiento del saber, la salvaguarda y desarrollo del patrimonio, la realidad y la imagen de los bienes de la naturaleza del hombre. Así mismo, existen diversas iniciativas para la creación de museos con enfoques distintos; tal como, el museo que fomenta la conservación y preservación del patrimonio intangible de algunos territorios, fortaleciendo su identidad; en concreto, el museo comunitario o bien el ecomuseo forman parte de estas instituciones con dichas iniciativas.
Dentro de los resultados obtenidos se encuentra el concepto de ecomuseo y su relación con el museo comunitario; de acuerdo a los trabajos científicos que se consultaron se aceptó la hipótesis de estudio.
En conclusión, los autores consultados en el tema de ecomuseo y museos comunitarios, señalan que son una herramienta para el rescate y preservación del patrimonio de un territorio, que reactiva la memoria colectiva, y siendo una alternativa de política pública para el desarrollo local. Por último, Borghi (2017:45) menciona que, cada ecomuseo, adopta un modelo que hace de la participación un elemento constitutivo de su identidad, y debe dotarse de instrumentos que la estimulen y la faciliten, instrumentos capaces de convertir a los ciudadanos en protagonistas activos en la experiencia de salvaguardia de su propio patrimonio
A New Integer Linear Programming Formulation to the Inverse QSAR/QSPR for Acyclic Chemical Compounds Using Skeleton Trees
33rd International Conference on Industrial, Engineering and Other Applications of Applied Intelligent Systems, IEA/AIE 2020, Kitakyushu, Japan, September 22-25, 2020.Computer-aided drug design is one of important application areas of intelligent systems. Recently a novel method has been proposed for inverse QSAR/QSPR using both artificial neural networks (ANN) and mixed integer linear programming (MILP), where inverse QSAR/QSPR is a major approach for drug design. This method consists of two phases: In the first phase, a feature function f is defined so that each chemical compound G is converted into a vector f(G) of several descriptors of G, and a prediction function ψ is constructed with an ANN so that ψ(f(G)) takes a value nearly equal to a given chemical property π for many chemical compounds G in a data set. In the second phase, given a target value y∗ of the chemical property π , a chemical structure G∗ is inferred in the following way. An MILP M is formulated so that M admits a feasible solution (x∗, y∗) if and only if there exist vectors x∗, y∗ and a chemical compound G∗ such that ψ(x∗)=y∗ and f(G∗)=x∗. The method has been implemented for inferring acyclic chemical compounds. In this paper, we propose a new MILP for inferring acyclic chemical compounds by introducing a novel concept, skeleton tree, and conducted computational experiments. The results suggest that the proposed method outperforms the existing method when the diameter of graphs is up to around 6 to 8. For an instance for inferring acyclic chemical compounds with 38 non-hydrogen atoms from C, O and S and diameter 6, our method was 5×104 times faster
Small dielectric spheres with high Refractive index as new multifunctional elements for optical devices
The future of ultra-fast optical communication systems is inevitably connected with progress in optical circuits and nanoantennas. One of the key points of this progress is the creation of elementary components of optical devices with scattering diagrams tailored for redirecting the incident light in a desired manner. Here we demonstrate theoretically and experimentally that a small, simple, spatially homogeneous dielectric subwavelength sphere with a high refractive index and low losses (as some semiconductors in the visible or near infrared region) exhibits properties allowing to utilize it as a new multifunctional element for the mentioned devices. This can be achieved by taking advantage of the coherent effects between dipolar and multipolar modes, which produce anomalous scattering effects. The effects open a new way to control the directionality of the scattered light. The directional tuning can be obtained in a practical way just by a change in the frequency of the incident wave, and/or by a well-chosen diameter of the sphere. Dielectric nanoparticles with the required optical properties in the VIS-NIR may be now readily fabricated. These particles could be an efficient alternative to the widely discussed scattering units with a more complicated design.This research was partly supported by MICINN (Spanish Ministry of Science and Innovation) through
project FIS2013-45854-P and by the Ministry of Education and Science of Russian Federation through
grant 14.Z50.31.0034
Effects of pulsed electric field on the viscoelastic properties of potato tissue
We have investigated whether transient permeabilization caused by the application of pulsed electric field would give rise to transient changes in the potato tissue viscoelastic properties. Potato tissue was subjected to nominal field strengths (E) ranging from 30 to 500 V/cm, with a single rectangular pulse of 10−5, 10−4, or 10−3 s. The changes on the viscoelastic properties of potato tissue during pulsed electric fields (PEF) were monitored through small amplitude oscillatory dynamic rheological measurements. The elastic (G′) and viscous moduli (G″) were measured every 30 s after the delivery of the pulse and the loss tangent change (tan-δ) was calculated. The results were correlated with measurements of changes on electrical resistance during the delivery of the pulse. Results show a drastic increase of tan-δ in the first 30 s after the application of the pulse, followed by a decrease 1 min after pulsation. This response is strongly influenced by pulsing conditions and is independent of the total permeabilization achieved by the pulse. Our results, supported by similar measurements on osmotically dehydrated control samples, clearly show that PEF causes a rapid change of the viscoelastic properties of the tissue that could be attributed to a partial loss in turgor pressure. This would be an expected consequence of electroporation. The recovery of tan-δ to values similar to those before pulsation strongly suggests recovery of cell membrane properties and turgor, pointing at reversible permeabilization of the cells. A slight increase of stiffness traduced by a negative change of tan-δ after application of certain PEF conditions may also give an indication of events occurring on cell wall structure due to stress responses. This study set the basis for further investigations on the complex cell stress physiology involving both cell membrane functional properties and cell wall structure that would influence tissue physical properties upon PEF application.Fundação para a Ciência e a Tecnologia (FCT
Evaluation of the Tsima community mobilization intervention to improve engagement in HIV testing and care in South Africa: study protocol for a cluster randomized trial
Abstract Background HIV transmission can be decreased substantially by reducing the burden of undiagnosed HIV infection and expanding early and consistent use of antiretroviral therapy (ART). Treatment as prevention (TasP) has been proposed as key to ending the HIV epidemic. To activate TasP in high prevalence countries, like South Africa, communities must be motivated to know their status, engage in care, and remain in care. Community mobilization (CM) has the potential to significantly increase uptake testing, linkage to and retention in care by addressing the primary social barriers to engagement with HIV care—including poor understanding of HIV care; fear and stigma associated with infection, clinic attendance and disclosure; lack of social support; and gender norms that deter men from accessing care. Methods/design Using a cluster randomized trial design, we are implementing a 3-year-theory-based CM intervention and comparing gains in HIV testing, linkage, and retention in care among individuals residing in 8 intervention communities to that of individuals residing in 7 control communities. Eligible communities include 15 villages within a health and demographic surveillance site (HDSS) in rural Mpumalanga, South Africa, that were not exposed to previous CM efforts. CM activities conducted in the 8 intervention villages map onto six mobilization domains that comprise the key components for community mobilization around HIV prevention. To evaluate the intervention, we will link a clinic-based electronic clinical tracking system in all area clinics to the HDSS longitudinal census data, thus creating an open, population-based cohort with over 30,000 18–49-year-old residents. We will estimate the marginal effect of the intervention on individual outcomes using generalized estimating equations. In addition, we will evaluate CM processes by conducting baseline and endline surveys among a random sample of 1200 community residents at each time point to monitor intervention exposure and community level change using validated measures of CM. Discussion Given the known importance of community social factors with regard to uptake of testing and HIV care, and the lack of rigorously evaluated community-level interventions effective in improving testing uptake, linkage and retention, the proposed study will yield much needed data to understand the potential of CM to improve the prevention and care cascade. Further, our work in developing a CM framework and domain measures will permit validation of a CM conceptual framework and process, which should prove valuable for community programming in Africa. Trial Registration NCT02197793 Registered July 21, 2014
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Sustainable development goal 2: improved targets and indicators for agriculture and food security
The pursuit of global food security and agricultural sustainability, the dual aim of the
second Sustainable Development Goal (SDG-2), requires urgent and concerted action
from developing and developed countries. This, in turn, depends on clear and
universally applicable targets and indicators which are partially lacking. The novel and
complex nature of the SDGs poses further challenges to their implementation on the
ground, especially in the face of interlinkages across SDG objectives and scales. Here
we review the existing SDG-2 indicators, propose improvements to facilitate their
operationalization and illustrate their practical implementation in Nigeria, Brazil and the
Netherlands. This exercise provides insights into the concrete actions needed to
achieve SDG-2 across contrasting development contexts and highlights the challenges
of addressing the links between targets and indicators within and beyond SDG-2.
Ultimately, it underscores the need for integrated policies and reveals opportunities to
leverage the fulfillment of SDG-2 worldwide
Synchronous bursts on scale-free neuronal networks with attractive and repulsive coupling
This paper investigates the dependence of synchronization transitions of
bursting oscillations on the information transmission delay over scale-free
neuronal networks with attractive and repulsive coupling. It is shown that for
both types of coupling, the delay always plays a subtle role in either
promoting or impairing synchronization. In particular, depending on the
inherent oscillation period of individual neurons, regions of irregular and
regular propagating excitatory fronts appear intermittently as the delay
increases. These delay-induced synchronization transitions are manifested as
well-expressed minima in the measure for spatiotemporal synchrony. For
attractive coupling, the minima appear at every integer multiple of the average
oscillation period, while for the repulsive coupling, they appear at every odd
multiple of the half of the average oscillation period. The obtained results
are robust to the variations of the dynamics of individual neurons, the system
size, and the neuronal firing type. Hence, they can be used to characterize
attractively or repulsively coupled scale-free neuronal networks with delays.Comment: 15 pages, 9 figures; accepted for publication in PLoS ONE [related
work available at http://arxiv.org/abs/0907.4961 and
http://www.matjazperc.com/
Gating of a pH-Sensitive K2P Potassium Channel by an Electrostatic Effect of Basic Sensor Residues on the Selectivity Filter
K+ channels share common selectivity characteristics but exhibit a wide diversity in how they are gated open. Leak K2P K+ channels TASK-2, TALK-1 and TALK-2 are gated open by extracellular alkalinization. The mechanism for this alkalinization-dependent gating has been proposed to be the neutralization of the side chain of a single arginine (lysine in TALK-2) residue near the pore of TASK-2, which occurs with the unusual pKa of 8.0. We now corroborate this hypothesis by transplanting the TASK-2 extracellular pH (pHo) sensor in the background of a pHo-insensitive TASK-3 channel, which leads to the restitution of pHo-gating. Using a concatenated channel approach, we also demonstrate that for TASK-2 to open, pHo sensors must be neutralized in each of the two subunits forming these dimeric channels with no apparent cross-talk between the sensors. These results are consistent with adaptive biasing force analysis of K+ permeation using a model selectivity filter in wild-type and mutated channels. The underlying free-energy profiles confirm that either a doubly or a singly charged pHo sensor is sufficient to abolish ion flow. Atomic detail of the associated mechanism reveals that, rather than a collapse of the pore, as proposed for other K2P channels gated at the selectivity filter, an increased height of the energetic barriers for ion translocation accounts for channel blockade at acid pHo. Our data, therefore, strongly suggest that a cycle of protonation/deprotonation of pHo-sensing arginine 224 side chain gates the TASK-2 channel by electrostatically tuning the conformational stability of its selectivity filter
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