X-ray Emission from SN 2012ca: A Type Ia-CSM Supernova Explosion in a Dense Surrounding Medium

X-ray emission is one of the signposts of circumstellar interaction in supernovae (SNe), but until now, it has been observed only in core-collapse SNe. The level of thermal X-ray emission is a direct measure of the density of the circumstellar medium (CSM), and the absence of X-ray emission from Type Ia SNe has been interpreted as a sign of a very low density CSM. In this paper, we report late-time (500--800 days after discovery) X-ray detections of SN 2012ca in {\it Chandra} data. The presence of hydrogen in the initial spectrum led to a classification of Type Ia-CSM, ostensibly making it the first SN~Ia detected with X-rays. Our analysis of the X-ray data favors an asymmetric medium, with a high-density component which supplies the X-ray emission. The data suggest a number density $> 10^8$ cm$^{-3}$ in the higher-density medium, which is consistent with the large observed Balmer decrement if it arises from collisional excitation. This is high compared to most core-collapse SNe, but it may be consistent with densities suggested for some Type IIn or superluminous SNe. If SN 2012ca is a thermonuclear SN, the large CSM density could imply clumps in the wind, or a dense torus or disk, consistent with the single-degenerate channel. A remote possibility for a core-degenerate channel involves a white dwarf merging with the degenerate core of an asymptotic giant branch star shortly before the explosion, leading to a common envelope around the SN.Comment: 11 pages, 4 figures. Accepted to MNRA

Neuronal networks in the developing brain are adversely modulated by early psychosocial neglect

The brain's neural circuitry plays a ubiquitous role across domains in cognitive processing and undergoes extensive re-organization during the course of development in part as a result of experience. In this paper we investigated the effects of profound early psychosocial neglect associated with institutional rearing on the development of task-independent brain networks, estimated from longitudinally acquired electroencephalographic (EEG) data from <30 to 96 months, in three cohorts of children from the Bucharest Early Intervention Project (BEIP), including abandoned children reared in institutions who were randomly assigned either to a foster care intervention or to remain in care as usual and never institutionalized children. Two aberrantly connected brain networks were identified in children that had been reared in institutions: 1) a hyper-connected parieto-occipital network, which included cortical hubs and connections that may partially overlap with default-mode network and 2) a hypo-connected network between left temporal and distributed bilateral regions, both of which were aberrantly connected across neural oscillations. This study provides the first evidence of the adverse effects of early psychosocial neglect on the wiring of the developing brain. Given these networks' potentially significant role in various cognitive processes, including memory, learning, social communication and language, these findings suggest that institutionalization in early life may profoundly impact the neural correlates underlying multiple cognitive domains, in ways that may not be fully reversible in the short term

Effects of Early Psychosocial Deprivation on the Development of Memory and Executive Function

This study investigated the effects of early institutional care on memory and executive functioning. Subjects were participants in the Bucharest Early Intervention Project (BEIP) and included institutionalized children, children with a history of institutionalization who were assigned to a foster care intervention, and community children in Bucharest, Romania. Memory and executive functioning were assessed at the age of 8 years using the Cambridge Neuropsychological Test and Automated Battery (CANTAB). As expected, children with a history of early institutional care performed worse on measures of both visual memory and executive functioning compared to their peers without a history of institutional care. In comparing children randomly assigned to the foster care intervention with their peers who had continued care in the institution, initial comparisons did not show significant differences on any of the memory or executive functioning outcomes. However, for one of the measures of executive functioning, after controlling for birth weight, head circumference, and duration of time spent in early institutional care, the foster care intervention was a significant predictor of scores. These results support and extend previous findings of deficits in memory and executive functioning among school-age children with a history of early deprivation due to institutional care. This study has implications for the millions of children who continue to experience the psychosocial deprivation associated with early institutional care

Timing of Intervention Affects Brain Electrical Activity in Children Exposed to Severe Psychosocial Neglect

Background: Early psychosocial deprivation has profound effects on brain activity in the young child. Previous reports have shown increased power in slow frequencies of the electroencephalogram (EEG), primarily in the theta band, and decreased power in higher alpha and beta band frequencies in infants and children who have experienced institutional care. Methodology/Principal Findings: We assessed the consequences of removing infants from institutions and placing them into a foster care intervention on brain electrical activity when children were 8 years of age. We found the intervention was successful for increasing high frequency EEG alpha power, with effects being most pronounced for children placed into foster care before 24 months of age. Conclusions/Significance: The dependence on age of placement for the effects observed on high frequency EEG alpha power suggests a sensitive period after which brain activity in the face of severe psychosocial deprivation is less amenable to recover

The Interaction of Photoactivators with Proteins during Microfabrication

Micron-scale protein cross-linking or microfabrication has been carried out using an Nd3+–YAG laser as the excitation source. Fabrication is carried out by the excitation of photoactivators (Rose Bengal, methylene blue and 9-fluorenone-2-carboxylic acid) with the ultimate goal of creating stable structures that will serve as models for various applications (drug delivery and tissue engineering). Experimental parameters have been adjusted to minimize photodamage and maximize cross-linking efficiency. The higher than ideal photon flux and peak power necessitates the use of high protein concentrations to minimize photodamage. Rose Bengal and methylene blue are binding to proteins with high association constants (Ka ≈ 106 M−1) and both Rose Bengal and both 9-fluorenone-2-carboxylic acid are showing changes to their excited states in presence of proteins at cross-linking concentrations. Molecular docking studies show that Rose Bengal binds close to the tryptophan with ΔG = −6.15 kcal/mol

Psychosocial Deprivation, Executive Functions, and the Emergence of Socio-Emotional Behavior Problems

Early psychosocial deprivation can negatively impact the development of executive functions (EFs). Here we explore the impact of early psychosocial deprivation on behavioral and physiological measures (i.e., event-related potentials; ERPs) of two facets of EF, inhibitory control and response monitoring, and their associations with internalizing and externalizing outcomes in the Bucharest Early Intervention Project (BEIP; Zeanah et al., 2003). This project focuses on two groups of children placed in institutions shortly after birth and then randomly assigned in infancy to either a foster care intervention or to remain in their current institutional setting. A group of community controls was recruited for comparison. The current study assesses these children at 8-years of age examining the effects of early adversity, the potential effects of the intervention on EF and the role of EF skills in socio-emotional outcomes. Results reveal exposure to early psychosocial deprivation was associated with impaired inhibitory control on a flanker task. Children in the foster care intervention exhibited better response monitoring compared to children who remained in the institution on the error-related positivity (Pe). Moreover, among children in the foster care intervention those who exhibited larger error-related negativity (ERN) responses had lower levels of socio-emotional behavior problems. Overall, these data identify specific aspects of EF that contribute to adaptive and maladaptive socio-emotional outcomes among children experiencing early psychosocial deprivation

The beneficial effects of a positive attention bias amongst children with a history of psychosocial deprivation

Children raised in institutions experience psychosocial deprivation that has detrimental influences on attention and mental health. The current study examined patterns of attention biases in children from institutions who were randomized at approximately 21.6 months to receive either a high-quality foster care intervention or care-as-usual. At age 12, children performed a dot-probe task and indices of attention bias were calculated. Additionally, children completed a social stress paradigm and cortisol reactivity was computed. Children randomized into foster care (N=40) exhibited an attention bias toward positive stimuli but not threat, whereas children who received care-as-usual (N=40) and a never-institutionalized comparison group (N=47) showed no bias. Stability of foster care placement was related to positive bias, while instability of foster care placement was related to threat bias. The magnitude of the positive bias was associated with fewer internalizing problems and better coping mechanisms. Within the foster care group, positive attention bias was related to less blunted cortisol reactivity

Transaction Costs in Payment of Environmental Service Contracts

Citation: Jeffrey M. Peterson, Craig M. Smith, John C. Leatherman, Nathan P. Hendricks, John A. Fox; Transaction Costs in Payment for Environmental Service Contracts, American Journal of Agricultural Economics, Volume 97, Issue 1, 1 January 2015, Pages 219–238, https://doi.org/10.1093/ajae/aau071Payment for environmental service contracts commonly require actions beyond adoption of a practice, such as undergoing specified enrollment procedures, granting consent to being monitored, and paying penalties for violations. These provisions are a bundle of attributes a landholder must accept with contract enrollment, leading to transaction costs in the contracting process. This article develops a principal–agent framework to study the links between these transaction costs and the well-known information asymmetries between the landholders and the government agency offering contracts. Using stated choice data collected from a sample of farmers, we estimate a mixed logit model to quantify the contribution of different contract attributes on contract willingness-to-accept (WTA). More stringent provisions in contracts were found to raise individual WTA by widely differing amounts across farmers, but the average effects imply that overall contract supply is sensitive to stringency. From a series of microsimulations based on the estimated model, we find that transaction costs create a significant drain on the cost-effectiveness of contracting from the agency’s point of view, similar in magnitude to the inefficiency created by hidden information. Although stringent contractual terms raise program expenditures, they may be justified if they raise compliance rates enough to offset the added cost. We also simulate an implicit frontier to trace out the change in compliance needed to justify a given increase in stringency. For environmental benefits in the range of previous estimates, this analysis suggests that stringent terms would need to substantially raise compliance rates to be cost effective