1,981 research outputs found
Effects of thickness on the spin susceptibility of the 2D electron gas
Using available quantum Monte Carlo predictions for a strictly 2D electron
gas, we have estimated the spin susceptibility of electrons in actual devices
taking into account the effect of the finite transverse thickness and finding a
very good agreement with experiments. A weak disorder, as found in very clean
devices and/or at densities not too low, just brings about a minor enhancement
of the susceptibility.Comment: 4 pages, 3 figure
Unraveling Adaptation in Eukaryotic Pathways: Lessons from Protocells
Eukaryotic adaptation pathways operate within wide-ranging environmental
conditions without stimulus saturation. Despite numerous differences in the
adaptation mechanisms employed by bacteria and eukaryotes, all require energy
consumption. Here, we present two minimal models showing that expenditure of
energy by the cell is not essential for adaptation. Both models share important
features with large eukaryotic cells: they employ small diffusible molecules
and involve receptor subunits resembling highly conserved G-protein cascades.
Analyzing the drawbacks of these models helps us understand the benefits of
energy consumption, in terms of adjustability of response and adaptation times
as well as separation of cell-external sensing and cell-internal signaling. Our
work thus sheds new light on the evolution of adaptation mechanisms in complex
systems.Comment: accepted for publication in PLoS Computational Biology; 19 pages, 8
figure
Parental brain: cerebral areas activated by infant cries and faces. A comparison between different populations of parents and not.
Literature about parenting traditionally focused on caring behaviors and parental representations. Nowadays, an innovative line of research, interested in evaluating the neural areas and hormones implicated in the nurturing and caregiving responses, has developed. The only way to permit a newborn to survive and grow up is to respond to his needs and in order to succeed it is necessary, \ufb01rst of all, that the adults around him understand what his needs are. That is why adults\u2019 capacity of taking care of infants cannot disregard from some biological mechanisms, which allow them to be more responsive to the progeny and to infants in general. Many researches have proved that exist speci\ufb01c neural basis activating in response to infant evolutionary stimuli, such as infant cries and infant emotional facial expression. There is a sort of innate predisposition
in human adults to respond to infants\u2019 signals, in order to satisfy their need and allow them to survive and become young adults capable of taking care of themselves. This article focuses on research that has investigated, in the last decade, the neural circuits underlying parental behavioral responses. Moreover, the paper compares the results of those studies that investigated the neural responses to infant stimuli under different
conditions: familiar versus unknown children, parents versus non-parents and normative versus clinical samples (depression, addiction, adolescence, and PTSD)
Maternal Drug Addiction: Influences on mother-child relationship and on early child development.
Much literature has pointed out parental drug addiction as a risk factor at multiple levels for the dyad, affecting parenting quality, child development and more globally the adult-child relationship. Drug addicted mothers are often reported as less sensitive, more intrusive and less able to regulate negative affects during early adult-child interactions. On the other hand, children of addicted mothers are often described as more irritable or more passive. The aim of this research was to investigate longitudinally the quality of adult-child relationship and of child interactive and emotional development in a group of drug addicted mothers and their children prenatally exposed to substances. The study involved 25 mother-child pairs (with children aged between 2 and 24 months) with drug addicted mothers. The dyads were followed for a 15 months-period and assessed regularly (every 3 months) through the application of the Emotional Availability Scales (EAS \u2013 Biringen, 2008) to videotaped free play interactions. In this way it has been possible to consider both the mothers\u2019 and the children\u2019s contribution to the development of their relationship.
The results were controversial, showing on one hand changes related only to specific EA dimensions and on the other hand patterns of changes that seemed characteristics of specific patterns of emotional availability. Dyads that initially showed interactions of better quality tended to improve their relationship during time, whereas dyads that exhibited more difficulties at the beginning of the study did not show improvements. Moreover, children of dyads which experienced interactions of better quality showed better interactive and emotional features than children of dyads characterized by more dysfunctional patterns of interaction. Dyads characterized by maternal drug addiction are often reported to be at higher risk for experiencing difficulties during everyday interactions and more likely to be associated to less optimal developmental outcomes. Anyway the results of our study highlight that, despite the condition of drug addiction, experiencing a relationship of good quality could be associated to better mother-child interactions and to more functional interactive and emotional development for children
The social assimilation of immigrants
The aim of this paper on the social assimilation of immigrants is to take a close look at migrants'social integration into the host country. The authors rely on the European Community Household panel (ECHP), which devotes a full module to the role and relevance of social relations for both migrants and natives. An innovative feature of this analysis is that it relies on migrants perceptions about their integration rather than - as is typically the case in most opinion surveys - on natives attitudes toward migrants. The main results of the paper can be summarized as follows. First, migrants - particularly from non-EU origins - are at a disadvantage in the fields of social relations. Even after controlling for their individual characteristics, such as age, education, family size, and employment status, they tend to socialize less than natives. Second, migrants tend to converge, albeit quite slowly, to the standard of natives. This finding highlights the risks of short term migration, where migrants tend to be constantly marginalized. Third, education has a significant impact on the type of social activities that individuals undertake. More educated people tend to relate somewhat less with their close neighborhood, but quite intensively with the broader community. The implication for policy makers concerned about the creation of ethnic enclaves is to promote education among immigrants'community.Population Policies,International Migration,Anthropology,Voluntary and Involuntary Resettlement,Human Migrations&Resettlements
Attachment representations and early interactions in drug addicted mothers: a case study of four women with distinct Adult Attachment Interview classifications
open4Drug addiction is considered a major risk factor that can inïŹuence maternal functioning at multiple levels, leading to less optimal parental qualities and less positive interactive exchanges in mother-child dyads. Moreover, drug abusers often report negative or traumatic attachment representations regarding their own childhood. These representations might affect, to some extent, later relational and developmental outcomes of their children. This study explored whether the development of dyadic interactions in addicted women differed based on attachment status. The longitudinal
ongoing of mother-child emotional exchanges was assessed among four mothers with four different attachment statuses (F-autonomous, E-preoccupied, Ds-dismissing, and U-unresolved/with losses). Attachment representations were assessed using the Adult Attachment Interview (
George et al., 1985), while mother-child interactions were evaluated longitudinally during videotaped play sessions, through the Emotional
Availability Scales (Biringen, 2008). As expected, the dyad with the autonomous mother showed better interactive functioning during play despite the condition of drug-abuse; the mother proved to be more affectively positive, sensitive, and responsive, while her baby showed a better organization of affects and behaviors. On the other side,insecure mothers seemed to experience more difïŹculties when interacting with their children showing inconsistency in the ability to perceive and respond to their babiesâ signals. Finally, children of insecure mothers showed less clear affects and signals. While differences between secure and insecure dyads appeared clear, differences between insecure patterns where less linear, suggesting a possible mediating role played by other factors. Clinical implications and suggestions for future research are discussed.openPorreca, A.; De Palo, F.; Simonelli, A.; Capra, N.Porreca, Alessio; DE PALO, Francesca; Simonelli, Alessandra; Capra, N
The Social Assimilation of Immigrants
Policy makers in migrant-receving countries must often strike a delicate balance between economic needs, that would dictate a substantial increase in the number of foreign workers, and political and electoral imperatives, that typically result in highly restrictive immigration policies. Promoting integration of migrants into the host country would go a long way in alleviating the trade off between economic and political considerations. While there is a large literature on the economic assimilation of immigrants, somewhat less attention has been devoted to other â and equally crucial â dimensions of migrantsâ integration, namely the process of social assimilation. The aim of this paper is to take a close look at migrants social integration into the host country. We rely on the European Community Household panel (ECHP), which devotes a full module to the role and relevance of social relations for both migrants and natives. An innovative feature of this analysis is that it relies on migrants perceptions about their integration rather than â as is typically the case in most opinion surveys â on natives attitudes toward migrants. The main results of the paper can be summarized as follows. First, migrants â particularly from non EU origins - are at a disadvantage in the fields of social relations. Even after controlling for their individual characteristics, such as age, education, family size, and employment status, they tend to socialize less than natives. Second, migrants tend to converge, albeit quite slowly, to the standard of natives. This finding highlight the risks of short term migration, where migrants tend to be constantly marginalized. Third, education has a significant impact on the type of social activities that individuals undertake. More educated people tend to relate somewhat less with their close neighbourhood, but quite intensively with the broader community. The implication for policy makers concerned about the creation of ethnic enclaves is to promote education among immigrantsâ community.
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