84 research outputs found
- DUOPOLY PRICE COMMUNICATION
We investigate the role of price communication in imperfect information environments by setting up a dynamic differentiated duopoly where actions are not observable and where firms decide, before pricing, whether to communicate their choices to the rivals. When firms play simultaneously in the pricing stages, communication across them is a dominant strategy allowing firms to coordinate prices, thus reducing competition. However, when communication takes place within pricing stages, this meaning that firms are given the opportunity to choose roles, the above firms coordination in prices is mitigated. This is because of the existence of a second mover advantage effect. Communication by the leader acts as a pre-commitment device to a price umbrella that the follower will undercut. As a result, we end up with a more competitive situation although price levels will not go down to those without communication.commitment, price communication
Extended Far-Infrared CO Emission in the Orion OMC-1 Core
We report on sensitive far-infrared observations of CO pure rotational
transitions in the OMC-1 core of Orion. The lines were observed with the Long
Wavelength Spectrometer (LWS) in the grating mode on board the Infrared Space
Observatory (ISO), covering the 43-197 m wavelength range. The transitions
from up to have been identified across the whole OMC-1
core and lines up to have been detected towards the central
region, KL/IRc2. In addition, we have taken high-quality spectra in the
Fabry-Perot mode of some of the CO lines. In KL/IRc2 the lines are
satisfactorily accounted for by a three-temperature model describing the
plateau and ridge emission. The fluxes detected in the high- transitions
() reveal the presence of a very hot and dense gas component
( K; =2\times 10^{17}\cmmd\rm H_2\geq 80$ K and as high as 150 K at some positions around IRc2,
from a simple Large-Velocity Gradient model.Comment: 10 pages, 3 figure
Caprellid assemblages (Crustacea: Amphipoda) in shallow waters invaded by Caulerpa racemosa var. cylindracea from southeastern Spain
Growth of the invasive algae Caulerpa racemosa var. cylindracea in shallow habitats may inXuence the
faunal assemblage composition. We studied its eVects on
caprellid assemblages associated with shallow-water habitats of hard and soft bottoms from the SE Iberian Peninsula
(native rocky-bottom algae, C. racemosa from hard and
soft bottoms, and Caulerpa prolifera, Cymodocea nodosa
and Posidonia oceanica from soft bottoms). Samples were
taken in two diVerent sampling periods (September 2004
and March 2005). A total of seven caprellid species were
identiWed, with important diVerences in their distribution in
diVerent habitats. Total abundance of caprellids was very
high in March on native algae on hard bottoms, and on
C. racemosa on both soft and hard bottoms. On both hard
and soft bottoms, abundances of Caprella hirsuta recorded
from C. racemosa were low. On the other hand, a higher
abundance of other species, namely C. acanthifera, C. santosrosai, Phtisica marina and Pseudoprotella phasma, was
recorded from C. racemosa. The results indicate that
C. racemosa may have a positive inXuence on some caprellid species, while seasonal changes are also evident. It is
concluded that introduced C. racemosa may serve as a new
habitat, promoting and maintaining caprellid populations in
shallow Mediterranean habitats.Ministerio de Educación y Ciencia de España y fondos FEDER de la Unión Europea. CGL2007-60044/BOSConsejería de Innovación, Ciencia y Empresa de la Junta de Andalucía. P07-RNM-0252
Left-handed musicians show a higher probability of atypical cerebral dominance for language
Music processing and right hemispheric language lateralization share a common network in the right auditory cortex and its frontal connections. Given that the development of hemispheric language dominance takes place over several years, this study tested whether musicianship could increase the probability of observing right language dominance in left-handers. Using a classic fMRI language paradigm, results showed that atypical lateralization was more predominant in musicians (40%) than in nonmusicians (5%). Comparison of left-handers with typical left and atypical right lateralization revealed that: (a) atypical cases presented a thicker right pars triangularis and more gyrified left Heschl's gyrus; and (b) the right pars triangularis of atypical cases showed a stronger intra-hemispheric functional connectivity with the right angular gyrus, but a weaker interhemispheric functional connectivity with part of the left Broca's area. Thus, musicianship is the first known factor related to a higher prevalence of atypical language dominance in healthy left-handed individuals. We suggest that differences in the frontal and temporal cortex might act as shared predisposing factors to both musicianship and atypical language lateralization
Sequential Exposure to Obesogenic Factors in Females Rats: From Physiological Changes to Lipid Metabolism in Liver and Mesenteric Adipose Tissue
During their lifetime, females are subjected to different nutritional and hormonal factors that could increase the risk of obesity and associated comorbidities. From early postnatal periods until the postmenopausal phase, exposure to over nutrition, high-energy diet and oestrogen deficiency, are considered as significant obesity risk factors in women. In this study, we assessed how key transitional life events and exposure to different nutrition influence energy homeostasis in a rat model. Specifically, we assessed the sequential exposure to postnatal over nutrition, high-fat diet (HFD) after weaning, followed later by ovariectomy (OVX; as a model of menopause). Each obesity risk factor increased significantly body weight (BW) and adiposity, with additive effects after sequential exposure. Increased energy intake in both HFD and/or OVX groups, and decreased locomotor activity and energy expenditure after OVX can explain these metabolic changes. Our study also documents decreased lipogenic pathway in mesenteric adipose tissue after HFD and/or OVX, independent of previous postnatal programming, yet only HFD evoked this effect in liver. In addition, we report an increase in the expression of the hepatic PEPCK depending on previous metabolic status. Overall, our results identify the impact of different risk factors, which will help in understanding the development of obesity in females
Neonatal overnutrition increases testicular size and expression of luteinizing hormone ß-subunit in peripubertal male rats
Proper nutrition is important for growth and development. Maturation of the reproductive axis and the timing of pubertal onset can be delayed when insufficient nutrition is available, or possibly advanced with nutritional abundance. The childhood obesity epidemic has been linked to a secular trend in advanced puberty in some populations. The increase in circulating leptin that occurs in association with obesity has been suggested to act as a signal that an adequate nutritional status exists for puberty to occur, allowing activation of central mechanisms. However, obesity-associated hyperleptinemia is linked to decreased leptin sensitivity, at least in adults. Here, we analyzed whether neonatal overnutrition modifies the response to an increase in leptin in peripubertal male rats, as previously demonstrated in females. Wistar rats were raised in litters of 4 (neonatal overnutrition) or 12 pups (controls) per dam. Leptin was administered sc (3 μg/g body weight) at postnatal day 35 and the rats killed 45 min or 2 h later. Postnatal overfeeding resulted in increased body weight and circulating leptin levels; however, we found no overweight-related changes in the mRNA levels of neuropeptides involved in metabolism or reproduction. In contrast, pituitary expression of luteinizing hormone (LH) beta-subunit was increased in overweight rats, as was testicular weight. There were no basal differences between L4 and L12 males or in their response to leptin administration in pSTAT3 levels in the hypothalamus at either 45 min or 2 h. In contrast, pJAK2 was found to be higher at 45 min in L4 compared to L12 males regardless of leptin treatment, while at 2 h it was higher in L4 leptin-treated males compared to L12 leptin-treated males, as well as L4 vehicle-treated rats. There were no changes in response to leptin administration in the expression of the neuropeptides analyzed. However, serum LH levels rose only in L4 males in response to leptin, but with no change in testosterone levels. In conclusion, the advancement in pubertal onset in males with neonatal overnutrition does not appear to be related to overt modifications in the central response to exogenous leptin during the peripubertal periodThe authors are funded by Fondos de Investigación Sanitaria (PI1600485 to JA), Ministerio de Ciencia e Innovación (BFU2014-51836-C2-2-R and BFU2017-82565-C2-1-R to JC) and fondos FEDER, Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (JA), and Fundación Endocrinología y Nutrició
Simulating the impact of non-pharmaceutical interventions limiting transmission in COVID-19 epidemics using a membrane computing model
[EN] Epidemics caused by microbial organisms are part of the natural phenomena of increasing biological complexity. The heterogeneity and constant variability of hosts, in terms of age, immunological status, family structure, lifestyle, work activities, social and leisure habits, daily division of time and other demographic characteristics make it extremely difficult to predict the evolution of epidemics. Such prediction is, however, critical for implementing intervention measures in due time and with appropriate intensity. General conclusions should be precluded, given that local parameters dominate the flow of local epidemics. Membrane computing models allows us to reproduce the objects (viruses and hosts) and their interactions (stochastic but also with defined probabilities) with an unprecedented level of detail. Our LOIMOS model helps reproduce the demographics and social aspects of a hypothetical town of 10 320 inhabitants in an average European country where COVID-19 is imported from the outside. The above-mentioned characteristics of hosts and their lifestyle are minutely considered. For the data in the Hospital and the ICU we took advantage of the observations at the Nursery Intensive Care Unit of the Consortium University General Hospital, Valencia, Spain (included as author). The dynamics of the epidemics are reproduced and include the effects on viral transmission of innate and acquired immunity at various ages. The model predicts the consequences of delaying the adoption of non-pharmaceutical interventions (between 15 and 45 days after the first reported cases) and the effect of those interventions on infection and mortality rates (reducing transmission by 20, 50 and 80%) in immunological response groups. The lockdown for the elderly population as a single intervention appears to be effective. This modeling exercise exemplifies the application of membrane computing for designing appropriate multilateral interventions in epidemic situations.MC and FB were sponsored by the Projects COV20 00067 of the
Program SARS-COV-2 and COVID-19 infection of the Instituto de
Salud Carlos III, Ministerio de Ciencia e Innovacion of Spain, CB06/02/0053 of the Centro de Investigacion Biom edica en Red de Epidemiolog¿a y Salud Publica (CIBERESP), and the Regional Government of Madrid (InGeMICS-B2017/BMD-3691). For JCG,
this study was partially founded by the Autonomous Community of Madrid, Spain (COVID-19 Grant, 2020) and the Ramon y Cajal Institute for Health Research (IRYCIS), Madrid, Spain.
For AM, this study was supported by grants from the Spanish
Ministry of Science and Innovation (PID2019-105969GB-I00), the
government of Valencia (project Prometeo/2018/A/133) and cofinanced by the European Regional Development Fund (ERDF).Campos Frances, M.; Sempere Luna, JM.; Galán, JC.; Moya, A.; Llorens, C.; De-Los-Angeles, C.; Baquero-Artigao, F.... (2021). Simulating the impact of non-pharmaceutical interventions limiting transmission in COVID-19 epidemics using a membrane computing model. microLife. 2:1-14. https://doi.org/10.1093/femsml/uqab011S114
Lower Aptian ammonite and carbon isotope stratigraphy in the eastern Prebetic Domain (Betic Cordillera, southeastern Spain)
Major global palaeobiologic and palaeoenvironmental changes occurred during the Early Aptian. Precise dating and timing of the different events is crucial to determine possible cause-effect relationships between them. In this regard, the combination of biostratigraphic and chemostratigraphic data can provide a very useful tool for time control. So far attempts to correlate the Lower Aptian carbon isotope record and the ammonite zonation yielded contradictory conclusions. In this paper, we present the results of an integrated analysis of the ammonite stratigraphic distribution and highresolution carbon isotope profiles from Lower Aptian sections of the eastern Prebetic Domain (Betic Cordillera, southeastern Spain). We recognized, in ascending order, the Deshayesites oglanlensis, Deshayesites forbesi, Deshayesites deshayesi, and Dufrenoyia furcata Zones. This succession is the same as that recently identified in the eastern Iberian Chain, and it closely correlates with both standard Mediterranean and Boreal zonations. The carbon isotope record displays the trends globally recognized for the Early Aptian, with two long positive shifts separated by a pronounced negative excursion. Calibration of this isotopic record with the ammonite zonation shows that the age of OAE 1a, which corresponds to the negative excursion and subsequent positive shift, is constrained to the middle/upper part of the Deshayesites forbesi Zone
Un trabajo colaborativo y de acompañamiento tutorial: el Plan de Acción Tutorial en la Facultad de Educación
El trabajo que se presenta refleja el trabajo colaborativo de la RED PAT-Educación en la que ha participado el profesorado integrante del Programa de Acción Tutorial (PAT) de la Facultad de Educación, dentro del Programa de REDES de investigación en docencia universitaria del ICE de la Universidad de Alicante. El objetivo del mismo es describir el Programa de acción tutorial (PAT) llevado a cabo durante el curso 2013/2014 en la Facultad de Educación así como analizar el desarrollo del mismo, desde la perspectiva de trabajo colaborativo entre el profesorado tutor participante y la puesta en práctica de un proceso de acompañamiento tutorial hacia el alumnado tutorado. Al mismo tiempo, se ha generado un trabajo conjunto con la inclusión de las TIC tanto para el profesorado tutor como para el alumnado tutorado a través de la creación del blog: http://edupatua.blogspot.com.es/ como recurso didáctico en el desarrollo de las tareas tutoriales, permitiéndonos conocer y analizar las necesidades y demandas del alumnado en este proceso de implementación del PAT. Los resultados obtenidos constatan fortalezas y debilidades que nos hacen reflexionar sobre las posibles propuestas de mejora que favorecerían el proceso de acompañamiento tutorial implementado
Role of neurokinin B in the control of female puberty and Its modulation by metabolic status
[Abstract] Human genetic studies have revealed that neurokinin B (NKB) and its receptor, neurokinin-3 receptor (NK3R), are essential elements for normal reproduction; however, the precise role of NKB–NK3R signaling in the initiation of puberty remains unknown. We investigated here the regulation of Tac2 and Tacr3 mRNAs (encoding NKB and NK3R, respectively) in female rats and demonstrated that their hypothalamic expression is increased along postnatal maturation. At puberty, both genes were widely expressed throughout the brain, including the lateral hypothalamic area and the arcuate nucleus (ARC)/medial basal hypothalamus, where the expression of Tacr3 increased across pubertal transition. We showed that central administration of senktide (NK3R agonist) induced luteinizing hormone (LH) secretion in prepubertal and peripubertal females. Conversely, chronic infusion of an NK3R antagonist during puberty moderately delayed the timing of vaginal opening (VO) and tended to decrease LH levels. The expression of NKB and its receptor was sensitive to changes in metabolic status during puberty, as reflected by a reduction in Tacr3 (and, to a lesser extent, Tac2) expression in the ARC after a 48 h fast. Yet, acute LH responses to senktide in pubertal females were preserved, if not augmented, under fasting conditions, suggesting sensitization of the NKB–NK3R–gonadotropin-releasing hormone signaling pathway under metabolic distress. Moreover, repeated administration of senktide to female rats with pubertal arrest due to chronic undernutrition rescued VO (in ∼50% of animals) and potently elicited LH release. Altogether, our observations suggest that NKB–NK3R signaling plays a role in pubertal maturation and that its alterations may contribute to pubertal disorders linked to metabolic stress and negative energy balance.Ministerio de Ciencia e Innovación; BFU 2008-00984Ministerio de Ciencia e Innovación; BFU 2011-25021Andalucía. Junta, P08-CVI-0060
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