1,413 research outputs found
Some Salient Features of Guatemala's Public and Private School Sectors
The purpose of this article is to analyze the formulation and implementation of educational policy processes in relation to private schools in Guatemala. Specifically, how bilingual education is defined and implemented in the private education sector in Guatemala City where the largest number of privately run establishments exist. Given the great deficits in the provision of educational coverage in the public sector, there has been an explosive expansion of private institutions which have very different levels of quality. Through an analysis of the administrative processes within the Guatemalan Government in general and its Education Ministry in particular as well as of the governance arrangements existing in the private school sector, an overall view of the curricular and policy decisions taken by private schools in the formulation and implementation of bilingual education is presented. This study was based on a sample of six private schools which cater to higher income segments of Guatemala City’s student population. Some of the relevant findings of this study include, the existence of a situation of quasi autonomous institutional functioning of the private sector, extreme differentials in the quality of services provided, inadequate levels of teacher and school administrator’s training as well as lack of cooperation between public and private sector schools
A Practical Approach to Protect IoT Devices against Attacks and Compile Security Incident Datasets
open access articleThe Internet of Things (IoT) introduced the opportunity of remotely manipulating home appliances (such as heating systems, ovens, blinds, etc.) using computers and mobile devices. This idea fascinated people and originated a boom of IoT devices together with an increasing demand that was difficult to support. Many manufacturers quickly created hundreds of devices implementing functionalities but neglected some critical issues pertaining to device security. This oversight gave rise to the current situation where thousands of devices remain unpatched having many security issues that manufacturers cannot address after the devices have been produced and deployed. This article presents our novel research protecting IOT devices using Berkeley Packet Filters (BPFs) and evaluates our findings with the aid of our Filter.tlk tool, which is able to facilitate the development of BPF expressions that can be executed by GNU/Linux systems with a low impact on network packet throughput
Control of the Radiative Heat Transfer in a Pair of Rotating Nanostructures
The fluctuations of the electromagnetic field are at the origin of the
near-field radiative heat transfer between nanostructures, as well as the
Casimir forces and torques that they exert on each other. Here, working within
the formalism of fluctuational electrodynamics, we investigate the simultaneous
transfer of energy and angular momentum in a pair of rotating nanostructures.
We demonstrate that, due to the rotation of the nanostructures, the radiative
heat transfer between them can be increased, decreased, or even reversed with
respect to the transfer that occurs in absence of rotation, which is solely
determined by the difference in the temperature of the nanostructures. This
work unravels the unintuitive phenomena arising from the simultaneous transfer
of energy and angular momentum in pairs of rotating nanostructures.Comment: 9 pages, 4 figure
A Multiple Classifier System Identifies Novel Cannabinoid CB2 Receptor Ligands
open access articleDrugs have become an essential part of our lives due to their ability to improve people’s
health and quality of life. However, for many diseases, approved drugs are not yet available
or existing drugs have undesirable side effects, making the pharmaceutical industry strive to
discover new drugs and active compounds. The development of drugs is an expensive
process, which typically starts with the detection of candidate molecules (screening) for an
identified protein target. To this end, the use of high-performance screening techniques has
become a critical issue in order to palliate the high costs. Therefore, the popularity of
computer-based screening (often called virtual screening or in-silico screening) has rapidly
increased during the last decade. A wide variety of Machine Learning (ML) techniques has
been used in conjunction with chemical structure and physicochemical properties for
screening purposes including (i) simple classifiers, (ii) ensemble methods, and more recently
(iii) Multiple Classifier Systems (MCS). In this work, we apply an MCS for virtual screening
(D2-MCS) using circular fingerprints. We applied our technique to a dataset of cannabinoid
CB2 ligands obtained from the ChEMBL database. The HTS collection of Enamine
(1.834.362 compounds), was virtually screened to identify 48.432 potential active molecules
using D2-MCS. This list was subsequently clustered based on circular fingerprints and from
each cluster, the most active compound was maintained. From these, the top 60 were kept,
and 21 novel compounds were purchased. Experimental validation confirmed six highly
active hits (>50% displacement at 10 ÎĽM and subsequent Ki determination) and an
additional five medium active hits (>25% displacement at 10 ÎĽM). D2-MCS hence provided a
hit rate of 29% for highly active compounds and an overall hit rate of 52%
Evolutionary Multi-objective Scheduling for Anti-Spam Filtering Throughput Optimization
This paper presents an evolutionary multi-objective optimization problem formulation for the anti-spam filtering problem, addressing both the classification quality criteria (False Positive and False Negative error rates) and email messages classification time (minimization). This approach is compared to single objective problem formulations found in the literature, and its advantages for decision support and flexible/adaptive anti-spam filtering configuration is demonstrated. A study is performed using the Wirebrush4SPAM framework anti-spam filtering and the SpamAssassin email dataset. The NSGA-II evolutionary multi-objective optimization algorithm was applied for the purpose of validating and demonstrating the adoption of this novel approach to the anti-spam filtering optimization problem, formulated from the multi-objective optimization perspective. The results obtained from the experiments demonstrated that this optimization strategy allows the decision maker (anti-spam filtering system administrator) to select among a set of optimal and flexible filter configuration alternatives with respect to classification quality and classification efficiency
Damage tolerance assessment by bend and shear tests of two multilayer composites: Glass fibre reinforced metal laminate and aluminium roll-bonded laminate
The damage tolerance of an aluminium roll-bonded laminate (ALH19) and a
glass fibre reinforced laminate (GLARE) (both based in Al 2024-T3) has been studied.
The composite laminates have been tested under 3-point bend and shear tests on the
interfaces to analyze their fracture behaviour. During the bend tests different fracture
mechanisms were activated for both laminates, which depend on the constituent
materials and their interfaces. The high intrinsic toughness of the pure Al 1050 layers
present in the aluminium roll-bonded laminate (ALH19), together with extrinsic
toughening mechanisms such as crack bridging and interface delamination were
responsible for the enhanced toughness of this composite laminate. On the other hand,
crack deflection by debonding between the glass fibres and the plastic resin in GLARE,
was the main extrinsic toughening mechanism present in this composite laminateFinancial support from CICYT (Project MAT2003-01172) is gratefully
acknowledged. C.M. Cepeda-Jiménez thanks the Spanish Ministry of Education and
Science for a Juan de la Cierva contract. Authors also thank Delft University of
Technology for providing the GLARE.Peer reviewe
LiDAR applications to the archaeological topography: The Irueña Hillfort (Fuenteguinaldo, Salamanca)
Este trabajo pretende demostrar la utilidad de las nuevas tecnologĂas de InformaciĂłn Geográfica (TIC) aplicadas a
las prospecciones extensivas en ArqueologĂa. Sobre un caso concreto, el llamado castro de Irueña, los autores han
realizado un estudio de campo combinando las prospecciones sobre el terreno con la aplicaciĂłn de tecnologĂas
LiDAR y SIG, para ofrecer una planta topográfica totalmente novedosa que permite, junto a algunos posibles hallazgos
externos, interpretar mejor los restos arqueolĂłgicos conocidos previamenteIn this paper, the authors try to defend the utilities that they have obteined from new geographical information technologies
to the Archaeological surveys. They have applied LiDAR system and GIS software, besides a ground survey,
over a study case, the so-called “castro de Irueña” (Salamanca, Spain) and they managed a new mapping of the site,
with new inside and outside findings that allow to explain much better archaeological remains from older excavationsTrabajo realizado dentro del proyecto HAR2016-77739-P
“La Arquitectura Protohistórica en el Occidente de la
Meseta. Arqueotectura y ArqueometrĂa aplicada al patrimonio
construido de los castros vettones.” del MINECO y de
la Unidad Asociada IAM – UAM “ANTA” del CSI
Finding positive health in “fortalezas” and “comunidad”: A case study of Latinos/X in Sonoma Valley
Background: Psychological literature and needs-assessment reports emphasize that Latinos/X in Sonoma Valley continue to be impacted by the detrimental effects of the 2017 Northern California wildfires (DomĂnguez & Yeh, 2018), current immigration enforcement practices, higher rates of poverty, lower educational attainment, persistent barriers to health care access, and obstacles to proportionate leadership representation compared to White American families. To cope with these disparities and navigate life adversities, Sonoma Valley Latinos/X often rely on “fortalezas” [strengths] and community, political, spiritual, cultural, and physical assets. These assets, which often include meaningful interactions with family, friends, neighbors, folk healers, faith-based organizations, and community members, must be incorporated when health care, community, and social service initiatives are designed and implemented.
Method: Our community-engaged research team (CERT) used asset-based community development (ABCD) as a conceptual framework (Kretzmann & McKnight, 1993) and community-based participatory research (CBPR) (Wallerstein & Duran, 2003) as a methodological approach to explore the assets and “fortalezas” [strengths] that have enabled Latinos/X to overcome adverse experiences i n Sonoma Valley. Five focus groups and 29 in-depth interviews were conducted because these methods are well-suited for Latino/X relational styles of “platicando” [small talk] (Delgado-Romero, Singh, & De Los Santos, 2018) . Participants were 18 years or older, lived or worked i n Sonoma Valley, and self-identified as Latino/X. Our sample included Latino/X parents, grandparents, artists, folk healers, health and social service providers, community leaders, students, and school personnel. Specific locations where interviews took place include the Hanna Institute, Nuestra Voz, La Luz Center, Center for Well-Being, Boys and Girls Clubs of Sonoma Valley, the Family Resource Center in El Verano, the Sonoma Valley Community Health Center, participants’ houses, and the broader Sonoma Valley community. Our research prioritized depth of relational engagement rather than sample size (Bowden, Caine, Yohani, 2017). We discontinued data collection once our research objectives were achieved and data saturation was accomplished. For data analysis, we used quasi-statistics to quantify the frequency of asset endorsement; open, axial, and selective coding to identify and categorize the assets; and GIS software for the creation of our two asset maps.
Findings: Findings indicate that Latinos/X are marginally positioned within Sonoma Valley society. Latinos/X have coped with and adapted to adverse conditions and disparities using and relying on a variety of informal networks and formal sources of support. Their decision to rely on one source of support over another is often based on (a) the extent to which they can afford the services or support required; (b) their particular needs, goals, or objectives at the time the help i s needed; (c) their preference for support resources that honor “respeto” [respect], “personalismo” [a preference for close personal attention i n relationships], and stable and welcoming intimate relationships with others; (d) the accessibility associated with pursuing these support services (e.g., geographic and transportation limitations); and (e) the extent to which culturally relevant and Spanish-speaking support can be found.
Dissemination: All data i n this study i s co-owned with the Sonoma Valley community. With the help of our community partners, this report was disseminated in Sonoma Valley during community meetings and forums, offering residents the opportunity to provide feedback, debate preliminary results, and assess whether their voices were captured accurately. Once the community expressed that the findings were representative of the Latino/X experience in Sonoma Valley, we finalized recommendations to assist community members, government officials, and health care and social service providers in designing culturally informed social, health, and/or community programs
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