Children\u27s learning of anxiety sensitivity : a preliminary study using a sample of youths referred for anxiety disorders

The purpose of the present study was to examine the origins of anxiety sensitivity (AS) by assessing youths\u27 learning experiences in relation to their AS symptoms and anxiety symptoms. Participants were 33 youths between 7 to 13 years old (M = 9.39 years, SD = 2.01). Youths were assessed using a structured interview and self-report measures. Chi-square analyses revealed no statistically significant differences in the proportions of boys vs. girls, Hispanic vs. non-Hispanic, and married vs. non-married. Pearson correlation analyses revealed that youths\u27 AS learning experiences were significantly related to youths\u27 AS and to youths\u27 anxiety symptoms scores. Partial correlations between youths\u27 learning experiences associated with AS symptoms in relation to AS scores controlling for anxiety symptoms effects were statistically significant. Findings were consistent with theory and suggest that learning mechanisms may be involved in AS acquisition and maintenance. The findings\u27 implications are discussed regarding possible learning experiences\u27 role in the development of AS

Learning to hunt Crocodiles: social organization in the process of knowledge generation and the emergence of management practices among Mayan of Mexico

Background New kinds of knowledge, usage patterns and management strategies of natural resources emerge in local communities as a way of coping with uncertainty in a changing world.Studying how human groups adapt and create new livelihoods strategies are important research topics for creating policies in natural resources management. Here, we study the adoption and development of lagartos (Crocodylus moreletii) commercial hunting by Mayan people from a communal land in Quintana Roo state. Two questions guided our work: how did the Mayan learn to hunt lagartos? And how, and in what context, did knowledge and management practices emerge? We believe that social structures, knowledge and preexisting skills facilitate the hunting learning process, but lagarto ecological knowledge and organizational practice were developed in a learning by doing process. Methods We conducted free, semi-structured and in-depth interviews over 17 prestigious lagartos hunters who reconstructed the activity through oral history. Then, we analyzed the sources of information and routes of learning and investigated the role of previous knowledge and social organization in the development of this novel activity. Finally, we discussed the emergence of hunting in relation to the characteristic of natural resource and the tenure system. Results Lagarto hunting for skin selling was a short-term activity, which represented an alternative source of money for some Mayans known as lagarteros. They acquired different types of knowledge and skills through various sources of experience (individual practice, or from foreign hunters and other Mayan hunters). The developed management system involved a set of local knowledge about lagartos ecology and a social organization structure that was then articulated in the formation of ?working groups? with particular hunting locations (rumbos and trabajaderos), rotation strategies and collaboration among them. Access rules and regulations identified were in an incipient state of development and were little documented. Conclusions In agreement to the hypothesis proposed, the Mayan used multiple learning paths to develop a new activity: the lagarto hunting. On the one hand, they used their traditional social organization structure as well as their culturally inherited knowledge. On the other hand, they acquired new ecological knowledge of the species in a learning-by-doing process, together with the use of other sources of external information. The formation of working groups, the exchange of information and the administration of hunting locations are similar to other productive activities and livelihood practiced by these Mayan. Skills such as preparing skins and lagartos ecological knowledge were acquired by foreign hunters and during hunting practice, respectively. We detected a feedback between local ecological knowledge and social organization, which in turn promoted the emergence of Mayan hunting management practices.Fil: Zamudio, Fernando. Universidad Nacional de Misiones. Facultad de Ciencias Forestales. Instituto de Biologia Subtropical - Sede Puerto Iguazu; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bello, Baltazar Eduardo. El Colegio de la Frontera del Sur; MéxicoFil: Estrada Lugo, Erin I. J.. El Colegio de la Frontera del Sur; Méxic

Exact monopole instantons and cosmological solutions in string theory from abelian dimensional reduction

We compute the exact string vacuum backgrounds corresponding to the non-compact coset theory $SU(2,1)/SU(2)$. The conformal field theory defined by the level $k= 4$ results in a five dimensional singular solution that factorizes in an asymptotic region as the linear dilaton solution and a $S^3$ model. It presents two abelian compact isometries that allow to reinterpreting it from a four dimensional point of view as a stationary and magnetically charged space-time resembling in some aspects the Kerr-Newman solution of general relativity. The $k=\frac{13}{7}$ theory on the other hand describes a cosmological solution that interpolates between a singular phase at short times and a $S^1 \times S^2$ universe after some planckian times.Comment: 18 pages, section 5 replaced by 5 and 6, references added; to appear in Phys. Rev.

Miniaturizable ion-selective arrays based on highly stable polymer membranes for biomedical applications

Poly(vinylchloride) (PVC) is the most common polymer matrix used in the fabrication of ion-selective electrodes (ISEs). However, the surfaces of PVC-based sensors have been reported to show membrane instability. In an attempt to overcome this limitation, here we developed two alternative methods for the preparation of highly stable and robust ion-selective sensors. These platforms are based on the selective electropolymerization of poly(3,4-ethylenedioxythiophene) (PEDOT), where the sulfur atoms contained in the polymer covalently interact with the gold electrode, also permitting controlled selective attachment on a miniaturized electrode in an array format. This platform sensor was improved with the crosslinking of the membrane compounds with poly(ethyleneglycol) diglycidyl ether (PEG), thus also increasing the biocompatibility of the sensor. The resulting ISE membranes showed faster signal stabilization of the sensor response compared with that of the PVC matrix and also better reproducibility and stability, thus making these platforms highly suitable candidates for the manufacture of robust implantable sensors. Keywords: ion-selective electrode (ISE) sensor, pH detection, ischemia, electrochemistry, implantable device, biomedicine, endoscop

Gravitational instantons and black plane solutions in 4-d string theory

We consider gauged Wess-Zumino models based on the non compact group $SU(2,1)$. It is shown that by vector gauging the maximal compact subgroup $U(2)$ the resulting backgrounds obey the gravity-dilaton one loop string vacuum equations of motion in four dimensional euclidean space. The torsionless solution is then interpreted as a pseudo-instanton of the $d=4$ Liouville theory coupled to gravity. The presence of a traslational isometry in the model allows to get another string vacuum backgrounds by using target duality that we identify with those corresponding to the axial gauging. We also compute the exact backgrounds. Depending on the value of $k$, they may be interpreted as instantons connecting a highly singular big bang like universe with a static singular or regular black plane geometry.Comment: 29 page

Bosonic Field Propagators on Algebraic Curves

In this paper we investigate massless scalar field theory on non-degenerate algebraic curves. The propagator is written in terms of the parameters appearing in the polynomial defining the curve. This provides an alternative to the language of theta functions. The main result is a derivation of the third kind differential normalized in such a way that its periods around the homology cycles are purely imaginary. All the physical correlation functions of the scalar fields can be expressed in terms of this object. This paper contains a detailed analysis of the techniques necessary to study field theories on algebraic curves. A simple expression of the scalar field propagator is found in a particular case in which the algebraic curves have $Z_n$ internal symmetry and one of the fields is located at a branch point.Comment: 26 pages, TeX + harvma

Configuring the neighbourhood effect in irregular cellular automata based models

Cellular automata (CA) models have been widely employed to simulate urban growth and land use change. In order to represent urban space more realistically, new approaches to CA models have explored the use of vector data instead of traditional regular grids. However, the use of irregular CA-based models brings new challenges as well as opportunities. The most strongly affected factor when using an irregular space is neighbourhood. Although neighbourhood definition in an irregular environment has been reported in the literature, the question of how to model the neighbourhood effect remains largely unexplored. In order to shed light on this question, this paper proposed the use of spatial metrics to characterise and measure the neighbourhood effect in irregular CA-based models. These metrics, originally developed for raster environments, namely the enrichment factor and the neighbourhood index, were adapted and applied in the irregular space employed by the model. Using the results of these metrics, distance-decay functions were calculated to reproduce the push-and-pull effect between the simulated land uses. The outcomes of a total of 55 simulations (five sets of different distance functions and eleven different neighbourhood definition distances) were compared with observed changes in the study area during the calibration period. Our results demonstrate that the proposed methodology improves the outcomes of the urban growth simulation model tested and could be applied to other irregular CA-based models

Formaldehyde Densitometry of Galactic Star-Forming Regions Using the H2CO 3(12)-3(13) and 4(13)-4(14) Transitions

We present Green Bank Telescope (GBT) observations of the 3(12)-3(13) (29 GHz) and 4(13)-4(14) (48 GHz) transitions of the H2CO molecule toward a sample of 23 well-studied star-forming regions. Analysis of the relative intensities of these transitions can be used to reliably measure the densities of molecular cores. Adopting kinetic temperatures from the literature, we have employed a Large Velocity Gradient (LVG) model to derive the average hydrogen number density [n(H2)] within a 16 arcsecond beam toward each source. Densities in the range of 10^{5.5}--10^{6.5} cm^{-3} and ortho-formaldehyde column densities per unit line width between 10^{13.5} and 10^{14.5} cm^{-2} (km s^{-1})^{-1} are found for most objects, in general agreement with existing measurements. A detailed analysis of the advantages and limitations to this densitometry technique is also presented. We find that H2CO 3(12)-3(13)/4(13)-4(14) densitometry proves to be best suited to objects with T_K >~ 100 K, above which the H2CO LVG models become relatively independent of kinetic temperature. This study represents the first detection of these H2CO K-doublet transitions in all but one object in our sample. The ease with which these transitions were detected, coupled with their unique sensitivity to spatial density, make them excellent monitors of density in molecular clouds for future experiments. We also report the detection of the 9_2--8_1 A^- (29 GHz) transition of CH3OH toward 6 sources.Comment: 17 pages; 6 figures; Accepted by Ap

Culture and the Emotion Socialization of Preschoolers

Objective:The present study examined mothers’ emotion socialization of 3-year–old children with behavior problems, to determine whether emotion socialization practices, as well as the relation between these practices and child functioning, varied across ethnicities. Method: Participants were 156 preschoolers with behavior problems. Mothers were European American (n = 98), Latina American (n = 40; predominately Puerto Rican), and African American (n = 18). Audio taped mother-child interactions were coded for emotion socialization behaviors. Results: Overall, this study provided evidence for both differences and similarities across ethnicities on parental emotion socialization practices. Ethnic differences in use of emotion socialization practices were only found for mothers’ emotion focused reactions, minimizing reactions, and non-responses to negative affect. However, ethnic differences emerged in the relations between emotion socialization practices and child functioning. Several emotion socialization parental behaviors were differentially related to current child internalizing and externalizing problems across ethnic groups. Conclusions: Results provide some support for the existence of cultural differences in emotion socialization practices and their associated child outcomes