Trading Off Generations: Infinitely-Lived Agent Versus OLG

The prevailing literature discusses intergenerational trade-offs predominantly in infinitely-lived agent models despite the finite lifetime of individuals. We discuss these trade-offs in a continuous time OLG framework and relate the results to the infinitely-lived agent setting. We identify three shortcomings of the latter: First, underlying normative assumptions about social preferences cannot be deduced unambiguously. Second, the distribution among generations living at the same time cannot be captured. Third, the optimal solution may not be implementable in overlapping generations market economies. Regarding the recent debate on climate change, we conclude that it is indispensable to explicitly consider the generations' life cycles.climate change; discounting; infinitely-lived agents; intergenerational equity; overlapping generations; time preference

Trading Off Generations: Infinitely Lived Agent Versus OLG

The prevailing literature discusses intergenerational trade-offs in climate change predominantly in terms of the Ramsey equation relying on the infinitely lived agent model. We discuss these trade-offs in a continuous time OLG framework and relate our results to the infinitely lived agent setting. We identify three shortcomings of the latter: First, underlying normative assumptions about social preferences cannot be deduced unambiguously. Second, the distribution among generations living at the same time cannot be captured. Third, the optimal solution may not be implementable in overlapping generations market economies.climate change, discounting, infinitely lived agents, intergenerational equity, overlapping generations, time preference

Trading Off Generations: Infinitely-Lived Agent Versus OLG

The prevailing literature discusses intergenerational trade-offs predominantly in infinitely-lived agent models despite the finite lifetime of individuals. We discuss these trade-offs in a continuous time OLG framework and relate the results to the infinitely-lived agent setting. We identify three shortcomings of the latter: First, underlying normative assumptions about social preferences cannot be deduced unambiguously. Second, the distribution among generations living at the same time cannot be captured. Third, the optimal solution may not be implementable in overlapping generations market economies. Regarding the recent debate on climate change, we conclude that it is indispensable to explicitly consider the generations’ life cycles

Controlling photocurrent channels in scanning tunneling microscopy

We investigate photocurrents driven by femtosecond laser excitation of a (sub)-nanometer tunnel junction in an ultrahigh vacuum low-temperature scanning tunneling microscope (STM). The optically driven charge transfer is revealed by tip retraction curves showing a current contribution for exceptionally large tip-sample distances, evidencing a strongly reduced effective barrier height for photoexcited electrons at higher energies. Our measurements demonstrate that the magnitude of the photo-induced electron transport can be controlled by the laser power as well as the applied bias voltage. In contrast, the decay constant of the photocurrent is only weakly affected by these parameters. Stable STM operation with photoelectrons is demonstrated by acquiring constant current topographies. An effective non-equilibrium electron distribution as a consequence of multiphoton absorption is deduced by the analysis of the photocurrent using a one-dimensional potential barrier model

A systematic review highlights the need to improve the quality and applicability of trials of physical therapy interventions for low back pain

Objectives: The objective of this study was to review and assess the methodological quality of randomized controlled trials that test physical therapy interventions for low back pain. Study Design and Setting: This is a systematic review of trials of physical therapy interventions to prevent or treat low back pain (of any duration or type) in participants of any age indexed on the Physiotherapy Evidence Database (PEDro). Existing PEDro scale ratings were used to evaluate methodological quality. Results: This review identified 2,215 trials. The majority of trials were for adults (n = 2136, 96.4%), low back pain without specific etiology (n = 1,863, 84.1%), and chronic duration (n = 947, 42.8%). The quality of trials improved over time; however, most were at risk of bias. Less than half of the trials concealed allocation to intervention (n = 813, 36.7%), used intention-to-treat principles (n = 778, 35.1%), and blinded assessors (n = 810, 36.6%), participants (n = 174, 7.9%), and therapists (n = 39, 1.8%). These findings did not vary by the type of therapy. Conclusion: Most trials that test physical therapy interventions for low back pain have methodological limitations that could bias treatment effect estimates. Greater attention to methodological features, such as allocation concealment and the reporting of intention-to-treat effects, would improve the quality of trials testing physical therapy interventions for low back pain

Sensitivity limitations in optical speed meter topology of gravitational-wave antennae

The possible design of QND gravitational-wave detector based on speed meter principle is considered with respect to optical losses. The detailed analysis of speed meter interferometer is performed and the ultimate sensitivity that can be achieved is calculated. It is shown that unlike the position meter signal-recycling can hardly be implemented in speed meter topology to replace the arm cavities as it is done in signal-recycled detectors, such as GEO 600. It is also shown that speed meter can beat the Standard Quantum Limit (SQL) by the factor of $\sim 3$ in relatively wide frequency band, and by the factor of $\sim 10$ in narrow band. For wide band detection speed meter requires quite reasonable amount of circulating power $\sim 1$ MW. The advantage of the considered scheme is that it can be implemented with minimal changes in the current optical layout of LIGO interferometer.Comment: 20 pages, 12 figure

Postoperative Immune Suppression in Visceral Surgery: Characterisation of an Intestinal Mouse Model

Background: Postoperatively acquired immune dysfunction is associated with a higher mortality rate in case of septic complications. As details of this severe clinical problem are still unknown, animal models are essential to characterise the mechanisms involved. Methods: Mice were laparotomised and the small intestine was pressed smoothly in antegrade direction. For extension of trauma, the intestine was manipulated three times consecutively. Following this, the ex vivo cytokine release of splenocytes was determined. The degree of surgical trauma was analysed by detection of HMGB1 and IL-6 in serum and by neutrophil staining in the muscularis mucosae. Results: We adapted the previously described animal model of intestinal manipulation to provide a model of surgically induced immune dysfunction. Following intestinal manipulation, the mice showed elevated serum levels of HMGB1 and IL-6 and increased infiltration of granulocytes into the muscularis mucosae. Ex vivo cytokine release by splenocytes was suppressed in the postoperative period. The degree of suppression correlated with the extent of surgical trauma. Conclusions: In this study, we describe a surgically induced immune dysfunction animal model, in which a significant surgical trauma is followed by an immune dysfunction. This model may be ideal for the characterisation of the postoperative immune dysfunction syndrome

A novel approach to assessment of US pediatric trauma system development.

Importance Mature trauma systems are critical in building and maintaining national, state, and local resilience against all-hazard disasters. Currently, pediatric state trauma system plans are not standardized and thus are without concrete measures of potential effectiveness. Objective To develop objective measures of pediatric trauma system capability at the state level, hypothesizing significant variation in capabilities between states, and to provide a contemporary report on the status of national pediatric trauma system planning and development. Design, Setting, and Participants A national survey was deployed in 2018 to perform a gap analysis of state pediatric trauma system capabilities. Four officials from each state were asked to complete the survey regarding extensive pediatric-related or specific trauma system parameters. Using these parameters, a panel of 14 individuals representing national stakeholder sectors in pediatric trauma care convened to identify the essential components of the ideal pediatric trauma system using Delphi methodology. Data analysis was conducted from March 16, 2019, to February 23, 2020. Main Outcomes and Measures Based on results from the national survey and consensus panel parameters, each state was given a composite score. The score was validated using US Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research (CDC WONDER) fatal injury database. Results The national survey had less than 10% missing data. The consensus panel reached agreement on 6 major domains of pediatric trauma systems (disaster, legislation/funding, access to care, injury prevention/recognition, quality improvement, pediatric readiness) and was used to develop the Pediatric Trauma System Assessment Score (PTSAS) based on 100 points. There was substantial variation across states, with state scores ranging from 48.5 to 100. Based on US CDC WONDER data, for every 1-point increase in PTSAS, there was a 0.12 per 100 000 decrease in mortality (95% CI, −0.22 to −0.02; P = .03). Conclusions and Relevance Results of this cross-sectional study suggest that a more robust pediatric trauma system has a significant association with pediatric injury mortality. This study assessed the national landscape of capability and preparedness to provide pediatric trauma care at the state level. These parameters can tailor the maturation of children’s interests within a state trauma system and assist with future state, regional, and national planning