Evaporation of buffer gas-thermalized anions out of a multipole rf ion trap

We identify plain evaporation of ions as the fundamental loss mechanism out of a multipole ion trap. Using thermalized negative Cl- ions we find that the evaporative loss rate is proportional to a Boltzmann factor. This thermodynamic description sheds new light on the dynamics of particles in time-varying confining potentials. It specifically allows us to extract the effective depth of the ion trap as the activation energy for evaporation. As a function of the rf amplitude we find two distinct regimes related to the stability of motion of the trapped ions. For low amplitudes the entire trap allows for stable motion and the trap depth increases with the rf field. For larger rf amplitudes, however, rapid energy transfer from the field to the ion motion can occur at large trap radii, which leads to a reduction of the effective trapping volume. In this regime the trap depth decreases again with increasing rf amplitude. We give an analytical parameterization of the trap depth for various multipole traps that allows predictions of the most favorable trapping conditions.Comment: Phys. Rev. Lett., in pres

Higher Anxiety Is Associated with Lower Cardiovascular Autonomic Function in Female Twins

Anxiety symptoms co-occur with cardiovascular health problems, with increasing evidence suggesting the role of autonomic dysfunction. Yet, there is limited behavior genetic research on underlying mechanisms. In this twin study, we investigated the phenotypic, genetic and environmental associations between a latent anxiety factor and three cardiovascular autonomic function factors: interbeat interval (IBI, time between heart beats), heart rate variability (HRV, overall fluctuation of heart-beat intervals) and baroreflex sensitivity (BRS, efficiency in regulating blood pressure [BP]). Multivariate twin models were fit using data of female twins (N = 250) of the Twin Interdisciplinary Neuroticism Study (TWINS). A significant negative association was identified between latent anxiety and BRS factors (r = -.24, 95% CI [-.40, -.07]). Findings suggest that this relationship was mostly explained by correlated shared environmental influences, and there was no evidence for pleiotropic genetic or unique environmental effects. We also identified negative relationships between anxiety symptoms and HRV (r = -.17, 95% CI [-.34, .00]) and IBI factors (r = -.13, 95% CI [-.29, .04]), though these associations did not reach statistical significance. Findings implicate that higher anxiety scores are associated with decreased efficiency in short-term BP regulation, providing support for autonomic dysfunction with anxiety symptomatology. The baroreflex system may be a key mechanism underlying the anxiety-cardiovascular health relationship

Single-shot temporal characterization of XUV pulses with duration from ~10 fs to ~350 fs at FLASH

Ultra-short extreme ultraviolet pulses from the free-electron laser FLASH are characterized using terahertz-field driven streaking. Measurements at different ultra-short extreme ultraviolet wavelengths and pulse durations as well as numerical simulations were performed to explore the application range and accuracy of the method. For the simulation of streaking, a standard classical approach is used which is compared to quantum mechanical theory, based on strong field approximation. Various factors limiting the temporal resolution of the presented terahertz streaking setup are investigated and discussed. Special attention is paid to the cases of very short (similar to 10 fs) and long (up to similar to 350 fs) pulses.We want to acknowledge the work of the scientific and technical team at FLASH. NMK acknowledges the hospitality and financial support from DESY and from the theory group in cooperation with the SQS research group of the European XFEL (Hamburg). KW and MD acknowledge support by the SFB925-A1. UF and AD acknowledge support by the excellence cluster `The Hamburg Center for Ultrafast Imaging-Structure, Dynamics and Control of Matter at the Atomic Scale' (DFG)-EXC 1074 project ID 194651731. SW acknowledges support by the DFG Forschergruppe FOR 1789. Editoria

Phylogenomics reveals the basis of adaptation of Pseudorhizobium species to extreme environments and supports a taxonomic revision of the genus

The family Rhizobiaceae includes many genera of soil bacteria, often isolated for their association with plants. Herein, we investigate the genomic diversity of a group of Rhizobium species and unclassified strains isolated from atypical environments, including seawater, rock matrix or polluted soil. Based on whole-genome similarity and core genome phylogeny, we show that this group corresponds to the genus Pseudorhizobium. We thus reclassify Rhizobium halotolerans, R. marinum, R. flavum and R. endolithicum as P. halotolerans sp. nov., P. marinum comb. nov., P. flavum comb. nov. and P. endolithicum comb. nov., respectively, and show that P. pelagicum is a synonym of P. marinum. We also delineate a new chemolithoautotroph species, P. banfieldiae sp. nov., whose type strain is NT-26 (=DSM 106348 =CFBP 8663 ). This genome-based classification was supported by a chemotaxonomic comparison, with increasing taxonomic resolution provided by fatty acid, protein and metabolic profiles. In addition, we used a phylogenetic approach to infer scenarios of duplication, horizontal transfer and loss for all genes in the Pseudorhizobium pangenome. We thus identify the key functions associated with the diversification of each species and higher clades, shedding light on the mechanisms of adaptation to their respective ecological niches. Respiratory proteins acquired at the origin of Pseudorhizobium were combined with clade-specific genes to enable different strategies for detoxification and nutrition in harsh, nutrient-poor environments. [Abstract copyright: Copyright © 2020 The Author(s). Published by Elsevier GmbH.. All rights reserved.

Cycles of Police Reform in Latin America.

yesOver the last quarter century post-conflict and post-authoritarian transitions in Latin America have been accompanied by a surge in social violence, acquisitive crime, and insecurity. These phenomena have been driven by an expanding international narcotics trade, by the long-term effects of civil war and counter-insurgency (resulting in, inter alia, an increased availability of small arms and a pervasive grammar of violence), and by structural stresses on society (unemployment, hyper-inflation, widening income inequality). Local police forces proved to be generally ineffective in preventing, resolving, or detecting such crime and forms of “new violence”3 due to corruption, frequent complicity in criminal networks, poor training and low pay, and the routine use of excessive force without due sanction. Why, then, have governments been slow to prioritize police reform and why have reform efforts borne largely “limited or nonexistent” long-term results? This chapter highlights a number of lessons suggested by various efforts to reform the police in Latin America over the period 1995-2010 . It focuses on two clusters of countries in Latin America. One is Brazil and the Southern Cone countries (Chile, Argentina, and Uruguay), which made the transition to democracy from prolonged military authoritarian rule in the mid- to late 1980s. The other is Central America and the Andean region (principally El Salvador, Guatemala, Honduras, Peru, and Colombia), which emerged/have been emerging from armed conflict since the mid- 1990s. The chapter examines first the long history of international involvement in police and security sector reform in order to identify long-run tropes and path dependencies. It then focuses on a number of recurring themes: cycles of de- and re-militarization of the policing function; the “security gap” and “democratization dilemmas” involved in structural reforms; the opportunities offered by decentralization for more community-oriented police; and police capacity to resist reform and undermine accountability mechanisms

MPA in Labor: Securing the Pearl Cays of Nicaragua

Implementation of Marine Protected Areas (MPAs) has always a step-zero, i.e., an initial phase when the idea is incepted, communicated and negotiated among stakeholders. What happens during this phase is likely to have an impact later on. If not done right, the management of the MPA may encounter problems at later stage that will be difficult to correct. Inspired by this working theory, this article describes the effort to establish the Pearl Cays off the Caribbean coast of Nicaragua as a protected area. This case-study illustrates the critical actions to be taken during step-zero, i.e., what needs to be considered and done before an MPA is formally declared. The area investigated consists of a number of small islands (cays) and coral reefs, fishing grounds and marine turtle nesting areas. Throughout history, the cays have played an important role in sustaining livelihoods of nearby communities. Although the idea of an MPA was originally conservation, the communities saw it as an opportunity to regain ownership and control of the cays. By Nicaraguan law, in order to establish protected areas, consultation and approval from local people is required. In the case of the Pearl Cays, this has proved difficult. The article demonstrates how MPA initiatives must sometimes relate to already ongoing complex social processes in the area where they are to be instigated

Estimating Effectiveness of the Control of Violence and Socioeconomic Development in Colombia: An Application of Dynamic Data Envelopment Analysis and Data Panel Approach

This paper develops an index to evaluate the level of effectiveness of the control of violence based on the data envelopment analysis approach. The index is used to examine the grade of effectiveness of the control of violence at the level of Colombian departments between 1993 and 2007. Comparing the results across Colombian departments, we find that the majority of departments show improvement in their scores of effectiveness. A second stage of the regression model reveals that departments with a higher gross domestic product and higher education and employment are more effective in the control of violence, whereas departments with higher political violence, unemployment rates, unsatisfied basic needs, a displaced population, and hectares cultivated with coca show lower effectiveness in the control of violence. All these findings are of particular interest in the formulation and development of policies against violence, taking into account that organised forms of violence, such as drug trafficking, impede the adequate effectiveness of its control. Moreover, violence decreases social investments, generating alterations in social services that produce long-run deterioration in faith in the government’s ability to govern, which should become an incentive to further violence