83 research outputs found
La percepción del tipo de liderazgo en la administración superior de la Universidad de Panamá: 1994.
La Universidad de Panamá nombra y separa su personal de
acuerdo a lo que disponen la Constitución y las leyes. En el estatuto Universitario se declara expresamente que la Universidad se regirá por principios democráticos. Consecuentemente, las autoridades universitarias deben responder a los requerimientos que la Constitución y las leyes señalan. ¿Cómo se ven a sí mismos los funcionarios superiores y ¿Cómo lo ven sus subalternos en función de la Teoría X y Y del Liderazgo de Douglas Mc Grego. Es decir ¿Responden las autoridades superiores a inclinarse hacia un tipo de liderazgo democrático o autoritario?.
De los Funcionarios examinados, todos se piensan de sí mismos en términos de líderes democráticos, pero la visión de los subalternos señala que el Vicerréctor de Asuntos Estudiantiles y el Secretario General son líderes autoritarios
Irreversible transformation of ferromagnetic ordered stripe domains in single-shot IR pump - resonant X-ray scattering probe experiments
The evolution of a magnetic domain structure upon excitation by an intense,
femtosecond Infra-Red (IR) laser pulse has been investigated using single-shot
based time-resolved resonant X-ray scattering at the X-ray Free Electron laser
LCLS. A well-ordered stripe domain pattern as present in a thin CoPd alloy film
has been used as prototype magnetic domain structure for this study. The
fluence of the IR laser pump pulse was sufficient to lead to an almost complete
quenching of the magnetization within the ultrafast demagnetization process
taking place within the first few hundreds of femtoseconds following the IR
laser pump pulse excitation. On longer time scales this excitation gave rise to
subsequent irreversible transformations of the magnetic domain structure. Under
our specific experimental conditions, it took about 2 nanoseconds before the
magnetization started to recover. After about 5 nanoseconds the previously
ordered stripe domain structure had evolved into a disordered labyrinth domain
structure. Surprisingly, we observe after about 7 nanoseconds the occurrence of
a partially ordered stripe domain structure reoriented into a novel direction.
It is this domain structure in which the sample's magnetization stabilizes as
revealed by scattering patterns recorded long after the initial pump-probe
cycle. Using micro-magnetic simulations we can explain this observation based
on changes of the magnetic anisotropy going along with heat dissipation in the
film.Comment: 16 pages, 6 figure
Spectral broadening enhancement in silicon waveguides through pulse shaping
Spectral broadening in silicon waveguides is usually inhibit at telecom wavelengths due to some adverse effects related to semiconductor dynamics, namely, two-photon and free-carrier absorption. In this work, our numerical simulations show that it is possible to achieve a significant enhancement in spectral broadening when we properly pre-shape the input pulse to reduce the impact of FCA on spectral broadening. Our analysis suggests that the use of input pulses with the correct skewness and power level is crucial for this achievemen
The Resource Leveling Problem with multiple resources using an adaptive genetic algorithm
Resource management ensures that a project is completed on time and at cost, and that its quality is as previously defined; nevertheless, resources are scarce and their use in the activities of the project leads to conflicts in the schedule. Resource Leveling Problems consider how to make the resource consumption as efficient as possible. This paper presents a new Adaptive Genetic Algorithm for the Resource Leveling Problem with multiple resources, and its novelty lies in using the Weibull distribution to establish an estimation of the global optimum as a termination condition. The extension of the project deadline with a penalty is allowed, avoiding the increase in the project criticality punishing the shift of activities. The algorithmis tested with the standard Project Scheduling Problem Library PSPLIB, and a complete analysis and benchmarking test instances are presented. The proposed algorithm is implemented using VBA for Excel 2010 in order to provide a flexible and powerful decision support system that enables practitioners to choose between different feasible solutions to a problem, and in addition it is easily adjustable to the constraints and particular needs of each project in realistic environments.This study was partially funded by the Spanish Ministry of Science and Innovation (research project BIA2011-23602).Ponz Tienda, JL.; Yepes Piqueras, V.; Pellicer Armiñana, E.; Moreno Flores, J. (2013). The Resource Leveling Problem with multiple resources using an adaptive genetic algorithm. Automation in Construction. 29(1):161-172. doi:10.1016/j.autcon.2012.10.003S16117229
Cytoadhesion to gC1qR through Plasmodium falciparum Erythrocyte Membrane Protein 1 in Severe Malaria
Cytoadhesion of Plasmodium falciparum infected erythrocytes to
gC1qR has been associated with severe malaria, but the parasite
ligand involved is currently unknown. To assess if binding to
gC1qR is mediated through the P. falciparum erythrocyte membrane
protein 1 (PfEMP1) family, we analyzed by static binding assays
and qPCR the cytoadhesion and var gene transcriptional profile
of 86 P. falciparum isolates from Mozambican children with
severe and uncomplicated malaria, as well as of a P. falciparum
3D7 line selected for binding to gC1qR (Pf3D7gC1qR). Transcript
levels of DC8 correlated positively with cytoadhesion to gC1qR
(rho = 0.287, P = 0.007), were higher in isolates from children
with severe anemia than with uncomplicated malaria, as well as
in isolates from Europeans presenting a first episode of malaria
(n = 21) than Mozambican adults (n = 25), and were associated
with an increased IgG recognition of infected erythrocytes by
flow cytometry. Pf3D7gC1qR overexpressed the DC8 type PFD0020c
(5.3-fold transcript levels relative to Seryl-tRNA-synthetase
gene) compared to the unselected line (0.001-fold). DBLbeta12
from PFD0020c bound to gC1qR in ELISA-based binding assays and
polyclonal antibodies against this domain were able to inhibit
binding to gC1qR of Pf3D7gC1qR and four Mozambican P. falciparum
isolates by 50%. Our results show that DC8-type PfEMP1s mediate
binding to gC1qR through conserved surface epitopes in DBLbeta12
domain which can be inhibited by strain-transcending functional
antibodies. This study supports a key role for gC1qR in
malaria-associated endovascular pathogenesis and suggests the
feasibility of designing interventions against severe malaria
targeting this specific interaction
Occupational Heat Exposure and Breast Cancer Risk in the MCC-Spain Study
[EN] Background: Mechanisms linking occupational heat exposure with chronic diseases have been proposed. However, evidence on occupational heat exposure and cancer risk is limited. Methods: We evaluated occupational heat exposure and female breast cancer risk in a large Spanish case-control study. We enrolled 1,738 breast cancer cases and 1,910 frequency-matched population controls. A Spanish job-exposure matrix, MatEmEsp, was used to assign estimates of the proportion of workers exposed (P >= 25% for at least 1 year) and work time with heat stress (wet bulb globe temperature ISO 7243) for each occupation. We used three exposure indices: ever versus never exposed, lifetime cumulative exposure, and duration of exposure (years). We estimated ORs and 95% confidence intervals (CI), applying a lag period of 5 years and adjusting for potential confounders. Results: Ever occupational heat exposure was associated with a moderate but statistically significant higher risk of breast cancer (OR 1.22; 95% CI, 1.01-1.46), with significant trends across categories of lifetime cumulative exposure and duration (P-trend = 0.01 and 0.03, respectively). Stronger associations were found for hormone receptor-positive disease (OR ever exposure = 1.38; 95% Cl, 1.12-1.67). We found no confounding effects from multiple other common occupational exposures; however, results attenuated with adjustment for occupational detergent exposure. Conclusions: This study provides some evidence of an association between occupational heat exposure and female breast cancer risk.SIThis study was partially funded by the “Accion Transversal del Cancer,” approved by the Spanish Ministry Council on October 11, 2007; the Instituto de Salud Carlos III-FEDER (PI08/1770, PI08/1359, PI09/00773, PI09/01286, PI09/01903, PI09/02078, PI09/01662, PI11/01403, PI11/01889, and PI12/00265); the Fundación Marqués de Valdecilla (API 10/09); the Junta de Castilla y León (LE22A10-2); the Consejería de Salud of the Junta de Andalucía (2009-S0143); the Conselleria de Sanitat of the Generalitat Valenciana (AP_061/10); the Recercaixa (2010ACUP 00310); the Regional Government of the Basque Country; the Consejería de Sanidad de la Región de Murcia; the European Commission grants FOOD-CT-2006–036224-HIWATE; the Spanish Association Against Cancer (AECC) Scientific Foundation; the Catalan Government DURSI grant 2014SGR647; the Secretariat for Universities and Research of the Ministry of Business and Knowledge of the Government of Catalonia (2017SGR1085); the Fundación Caja de Ahorros de Asturias; and the University of Oviedo. M.C. Turner is funded by a Ramón y Cajal fellowship (RYC-2017-01892) from the Spanish Ministry of Science, Innovation and Universities and co-funded by the European Social Fund. The authors acknowledge support from the Spanish Ministry of Science and Innovation through the “Centro de Excelencia Severo Ochoa 2019–2023” Program (CEX2018-000806-S) and support from the Generalitat de Catalunya through the CERCA Program. Statistical assistance provided by Ana Espinosa Morano was greatly appreciated
Predicting Outcomes in Pediatric Crohn’s Disease for Management Optimization: Systematic Review and Consensus Statements from PIBD-Ahead Program
A better understanding of prognostic factors within the heterogeneous spectrum of pediatric Crohn's disease (CD) should improve patient management and reduce complications. We aimed to identify evidence-based predictors of outcomes with the goal of optimizing individual patient management. A survey of 202 experts in pediatric CD identified and prioritized adverse outcomes to be avoided. A systematic review of the literature with meta-analysis, when possible, was performed to identify clinical studies that investigated predictors of these outcomes. Multiple national and international face-to-face meetings were held to draft consensus statements based on the published evidence. Consensus was reached on 27 statements regarding prognostic factors for surgery, complications, chronically active pediatric CD, and hospitalization. Prognostic factors for surgery included CD diagnosis during adolescence, growth impairment, NOD2/CARD15 polymorphisms, disease behavior, and positive anti-Saccharomyces cerevisiae antibody status. Isolated colonic disease was associated with fewer surgeries. Older age at presentation, small bowel disease, serology (anti-Saccharomyces cerevisiae antibody, antiflagellin, and OmpC), NOD2/CARD15 polymorphisms, perianal disease, and ethnicity were risk factors for penetrating (B3) and/or stenotic disease (B2). Male sex, young age at onset, small bowel disease, more active disease, and diagnostic delay may be associated with growth impairment. Malnutrition and higher disease activity were associated with reduced bone density. These evidence-based consensus statements offer insight into predictors of poor outcomes in pediatric CD and are valuable when developing treatment algorithms and planning future studies. Targeted longitudinal studies are needed to further characterize prognostic factors in pediatric CD and to evaluate the impact of treatment algorithms tailored to individual patient risk
Sleep duration and napping in relation to colorectal and gastric cancer in the MCC-Spain study
[EN] Sleep duration is a novel and potentially modifiable risk factor for cancer. We evaluated the association of self‑reported sleep duration and daytime napping with odds of colorectal and gastric cancer. We included 2008 incident colorectal cancer cases, 542 gastric cancer cases and 3622 frequency‑matched population controls, recruited in the MCC‑Spain case–control study (2008–2013). Sleep information, socio‑demographic and lifestyle characteristics were obtained through personal interviews. Multivariable adjusted logistic regression models were used to estimate odds ratios (OR) with 95% confidence intervals (CI) for cancer, across categories of sleep duration (≤ 5, 6, 7, 8, ≥ 9 hours/day),
daytime napping frequency (naps/week) and duration (minutes/nap). Compared to 7 hours of sleep,
long sleep was associated with increased odds of colorectal (OR ≥9 hours : 1.59; 95%CI 1.30–1.94) and
gastric cancer (OR ≥9 hours : 1.95; 1.37–2.76); short sleep was associated with increased odds of gastric
cancer (OR ≤5 hours : 1.32; 0.93–1.88). Frequent and long daytime naps increased the odds of colorectal
(OR6–7 naps/week, ≥30 min : 1.32; 1.14–1.54) and gastric cancer (OR 6–7 naps/week, ≥30 min : 1.56; 1.21–2.02). Effects of short sleep and frequent long naps were stronger among participants with night shift‑work history. Sleep and circadian disruption may jointly play a role in the etiology of colorectal and gastric cancerS
Sleep duration and napping in relation to colorectal and gastric cancer in the MCC-Spain study
Sleep duration is a novel and potentially modifiable risk factor for cancer. We evaluated the association of self-reported sleep duration and daytime napping with odds of colorectal and gastric cancer. We included 2008 incident colorectal cancer cases, 542 gastric cancer cases and 3622 frequency-matched population controls, recruited in the MCC-Spain case-control study (2008-2013). Sleep information, socio-demographic and lifestyle characteristics were obtained through personal interviews. Multivariable adjusted logistic regression models were used to estimate odds ratios (OR) with 95% confidence intervals (CI) for cancer, across categories of sleep duration (? 5, 6, 7, 8, ? 9 hours/day), daytime napping frequency (naps/week) and duration (minutes/nap). Compared to 7 hours of sleep, long sleep was associated with increased odds of colorectal (OR?9 hours: 1.59; 95%CI 1.30-1.94) and gastric cancer (OR?9 hours: 1.95; 1.37-2.76); short sleep was associated with increased odds of gastric cancer (OR?5 hours: 1.32; 0.93-1.88). Frequent and long daytime naps increased the odds of colorectal (OR6-7 naps/week, ?30 min: 1.32; 1.14-1.54) and gastric cancer (OR6-7 naps/week, ?30 min: 1.56; 1.21-2.02). Effects of short sleep and frequent long naps were stronger among participants with night shift-work history. Sleep and circadian disruption may jointly play a role in the etiology of colorectal and gastric cancer.Funding: The study was funded by the “Accion Transversal del Cancer”, approved on the Spanish Ministry Council on 11 October 2007, by the Instituto de Salud Carlos III-FEDER (PI08/1770, PI08/0533, PI08/1359, PI09/00773-Cantabria, PI09/01286-León, PI09/01903-Valencia, PI09/02078-Huelva, PI09/01662-Granada, PI11/01403, PI11/01889-FEDER, PI11/00226, PI11/01810, PI11/02213, PI12/00488, PI12/00265, PI12/01270, PI12/00715, PI12/00150), by the Fundación Marqués de Valdecilla (API 10/09), by the ICGC International Cancer Genome Consortium CLL (The ICGC CLL-Genome Project is funded by Spanish Ministerio de Economía y Competitividad (MINECO) through the Instituto de Salud Carlos III (ISCIII) and Red Temática de Investigación del Cáncer (RTICC) del ISCIII (RD12/0036/0036)), by the Junta de Castilla y León (LE22A10-2), by the Consejería de Salud of the Junta de Andalucía (2009-S0143), by the Conselleria de Sanitat of the Generalitat Valenciana (AP_061/10), by the Recercaixa (2010ACUP 00310), by the European Commission grants FOOD-CT-2006-036224-HIWATE, by the Spanish Association Against Cancer (AECC) Scientific Foundation, by the Catalan Government DURSI grant 2009SGR1489. KP received a predoctoral grant PFIS (FI09/00385). MCT is funded by a Ramón y Cajal fellowship (RYC-2017-01892) from the Spanish Ministry of Science, Innovation and Universities and cofunded by the European Social Fund. ISGlobal acknowledges support from the Spanish Ministry of Science and Innovation through the “Centro de Excelencia Severo Ochoa 2019–2023” Program (CEX2018-000806-S), and support from the Generalitat de Catalunya through the CERCA Program. Agency for Management of University and Research Grants (AGAUR) of the Catalan Government grant 2017SGR723. Spanish Association Against Cancer (AECC) Scientific Foundation. DC is supported by Spanish Ministry of Economy and Competitiveness—Carlos III Institute of Health cofunded by FEDER funds/European Regional Develpment Fund (ERDF)—a way to build Europe (PI17/01280), the Centro de Investigacion Biomedica en Red: Epidemiologia y Salud Publica (CIBERESP, Spain) and the Agencia de Gestio d’Ajuts Universitaris i de Recerca (AGAUR), CERCA Programme/Generalitat de Catalunya for institutional suport (2017SGR1085). VM is funded by the Agency for Management of University and Research Grants (AGAUR) of the Catalan Government grant 2017SGR723; Instituto de Salud Carlos III, co-funded by FEDER funds—a way to build Europe—; Spanish Association Against Cancer (AECC) Scientific Foundation. Sample collection of this work was supported by the Xarxa de Bancs de Tumors de Catalunya sponsored by Pla Director d’Oncología de Catalunya (XBTC)", Plataforma Biobancos PT13/0010/0013" and ICOBIOBANC, sponsored by the Catalan Institute of Oncology. We thank CERCA Program, Generalitat de Catalunya for institutional support
A Relationship between Carotenoid Accumulation and the Distribution of Species of the Fungus Neurospora in Spain
The ascomycete fungus Neurospora is present in many parts of the world, in particular in tropical and subtropical areas, where it is found growing on recently burned vegetation. We have sampled the Neurospora population across Spain. The sampling sites were located in the region of Galicia (northwestern corner of the Iberian peninsula), the province of Cáceres, the city of Seville, and the two major islands of the Canary Islands archipelago (Tenerife and Gran Canaria, west coast of Africa). The sites covered a latitude interval between 27.88° and 42.74°. We have identified wild-type strains of N. discreta, N. tetrasperma, N. crassa, and N. sitophila and the frequency of each species varied from site to site. It has been shown that after exposure to light Neurospora accumulates the orange carotenoid neurosporaxanthin, presumably for protection from UV radiation. We have found that each Neurospora species accumulates a different amount of carotenoids after exposure to light, but these differences did not correlate with the expression of the carotenogenic genes al-1 or al-2. The accumulation of carotenoids in Neurospora shows a correlation with latitude, as Neurospora strains isolated from lower latitudes accumulate more carotenoids than strains isolated from higher latitudes. Since regions of low latitude receive high UV irradiation we propose that the increased carotenoid accumulation may protect Neurospora from high UV exposure. In support of this hypothesis, we have found that N. crassa, the species that accumulates more carotenoids, is more resistant to UV radiation than N. discreta or N. tetrasperma. The photoprotection provided by carotenoids and the capability to accumulate different amounts of carotenoids may be responsible, at least in part, for the distribution of Neurospora species that we have observed across a range of latitudes
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