Creation of Electron--Positron Wind in Gamma-Ray Bursts and Its Effect on the Early Afterglow Emission

We calculate the creation of electron--positron pairs in Gamma-Ray Bursts (GRBs) resulting from the collision between scattered and outward moving gamma-ray photons. The number of pairs exceeds the number of ambient medium electrons encountered by the GRB ejecta up to ~ 10^{16} cm from the center of explosion. The shock resulting from the interaction of the ejecta with the pair-wind may brighten the afterglow synchrotron emission during the first few minutes. Even without this effect, the peak intensity of the optical afterglow increases with the density of the surrounding medium. Therefore, observations of the optical flux at early times constrain the density of the circumburst medium. If the electron and magnetic field energies behind the forward shock sweeping-up the pair-wind and the circumburst medium are as inferred from fits to the broadband afterglow emission at 0.5-100 days, then the current upper limits on the optical counterpart emission, set by the ROTSE and LOTIS experiments, indicate that the circumburst medium within 0.01 pc is less dense than 100 cm^{-3} or, if a wind, corresponds to a progenitor mass-loss to wind speed ratio below 10^{-6} M_sun/yr/(1000 km/s).Comment: 9 pages, submitted to MNRAS in 200

ESCAP CovCAP survey of heads of academic departments to assess the perceived initial (April/May 2020) impact of the COVID-19 pandemic on child and adolescent psychiatry services.

In April 2020, the European Society for Child and Adolescent Psychiatry (ESCAP) Research Academy and the ESCAP Board launched the first of three scheduled surveys to evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on child and adolescent psychiatry (CAP) services in Europe and to assess the abilities of CAP centers to meet the new challenges brought on by the crisis. The survey was a self-report questionnaire, using a multistage process, which was sent to 168 heads of academic CAP services in 24 European countries. Eighty-two responses (56 complete) from 20 countries, representing the subjective judgement of heads of CAP centers, were received between mid-April and mid-May 2020. Most respondents judged the impact of the crisis on the mental health of their patients as medium (52%) or strong (33%). A large majority of CAP services reported no COVID-19 positive cases among their inpatients and most respondents declared no or limited sick leaves in their team due to COVID-19. Outpatient, daycare, and inpatient units experienced closures or reductions in the number of treated patients throughout Europe. In addition, a lower referral rate was observed in most countries. Respondents considered that they were well equipped to handle COVID-19 patients despite a lack of protective equipment. Telemedicine was adopted by almost every team despite its sparse use prior to the crisis. Overall, these first results were surprisingly homogeneous, showing a substantially reduced patient load and a moderate effect of the COVID-19 crisis on psychopathology. The effect on the organization of CAP services appears profound. COVID-19 crisis has accelerated the adoption of new technologies, including telepsychiatry

Home-Range Size of White-Headed Woodpeckers in W est- Central Idaho

The white-headed woodpecker (Picoides albolarvatus) is a species of management concern in dry-conifer forests of the Inland Northwest, where forest restoration and fuels reduction treatments are increasingly common.  This species may be vulnerable to forest management treatments because it occupies a limited distribution and has narrow habitat requirements.  Forest treatments could negatively affect this species if foraging and nesting resources are removed or could benefit the species through creation of more heterogeneity across the landscape.  Studies of other woodpecker species have identified resource availability and habitat composition as a key influence on the variation of home range size within a population.  We examined home range size of white-headed woodpeckers in a landscape historically managed for timber harvest and is currently receiving extensive forest restoration treatments.  In our first field season, we obtained relocations on 7 radio-tagged woodpeckers (5 males and 2 females, all from different breeding pairs), from late nesting through fledgling periods (late June to early September).  We obtained direct foraging observations at the radio locations.  Estimated home range sizes were quite variable(24 - 180 ha), based on the minimum convex polygon (MCP) method.  We will also estimate home range sizes using the fixed-kernel method.  Identifying habitat spatial attributes that account for variation in home range size will contribute towards effective management decisions for the persistence of white-headed woodpecker populations

Landscape Heterogeneity at White-Headed Woodpecker Nest Sites in West-Central Idaho

The white-headed woodpecker (Picoides albolarvatus) is a regional endemic species of dry conifer forests in the Inland Pacific Northwest, where forest restoration activities are increasingly common. Recent efforts to mitigate severe fire effects and restore ecological function in these forests have prompted land managers to consider the implications of forest management actions on a range of resources, including wildlife. Identifying the associations of sensitive wildlife species with the structure and distribution of resources across landscapes is necessary for scientifically-sound management decisions. We examined the heterogeneity and proportion of open- and closed- canopy forest patches surrounding white-headed woodpecker nest sites during 2012 and 2013. We used logistic regression to compare differences between nest (n = 34) and non-nest (n = 184) sites. We found a stronger positive relationship with low canopy closure within 1-ha of nest sites compared with non-nest sites (nests: x? = 0.49, SD = 0.43; non-nests: x? = 0.06, SD = 0.16; P < 0.001). We also measured a stronger positive relationship with the edge density between low and moderate canopy patches within a 1-km radius of nest sites compared with non-nest sites (nests: x? = 30.0 meters/ha, SD = 14.6; non-nests: x? = 18.4 m/ha, SD = 14.9; P < 0.001). Our results are consistent with studies of nesting white-headed woodpeckers in Oregon. These data will help further validate and refine habitat suitability models across their northern range and contribute towards effective management decisions that will benefit the white-headed woodpecker

Deflation and depression: Is there an empirical link?

Are deflation and depression empirically linked? No, concludes a broad historical study of inflation and real output growth rates. Deflation and depression do seem to have been linked during the 1930s. But in the rest of the data for 17 countries and more than 100 years, there is virtually no evidence of such a link

Modeling the transition to a new economy: Lessons from two technological revolutions

Many view the period after the Second Industrial Revolution as a paradigm of a transition to a new economy following a technological revolution, including the Information Technology Revolution. We build a quantitative model of diffusion and growth during transitions to evaluate that view. With a learning process quantified by data on the life cycle of US manufacturing plants, the model accounts for the key features of the transition after the Second Industrial Revolution. But we find that features like those will occur in other transitions only if a large amount of knowledge about old technologies exists before the transition begins

Modeling and measuring organization capital

Manufacturing plants have a clear life cycle: they are born small, grow substantially with age, and eventually die. Economists have long thought that this life cycle is driven by organization capital, the accumulation of plant‐specific knowledge. The location of plants in the life cycle determines the size of the payments, or organization rents, plant owners receive from organization capital. These payments are compensation for the interest cost to plant owners of waiting for their plants to grow. We use a quantitative growth model of the life cycle of plants, along with U.S. data, to infer the overall size of these payments