Stabilisation of BGK modes by relativistic effects

Context. We examine plasma thermalisation processes in the foreshock region of astrophysical shocks within a fully kinetic and self-consistent treatment. We concentrate on proton beam driven electrostatic processes, which are thought to play a key role in the beam relaxation and the particle acceleration. Our results have implications for the effectiveness of electron surfing acceleration and the creation of the required energetic seed population for first order Fermi acceleration at the shock front. Aims. We investigate the acceleration of electrons via their interaction with electrostatic waves, driven by the relativistic Buneman instability, in a system dominated by counter-propagating proton beams. Methods. We adopt a kinetic Vlasov-Poisson description of the plasma on a fixed Eulerian grid and observe the growth and saturation of electrostatic waves for a range of proton beam velocities, from 0.15c to 0.9c. Results. We can report a reduced stability of the electrostatic wave (ESW) with increasing non-relativistic beam velocities and an improved wave stability for increasing relativistic beam velocities, both in accordance with previous findings. At the highest beam speeds, we find the system to be stable again for a period of ≈160 plasma periods. Furthermore, the high phase space resolution of the Eulerian Vlasov approach reveals processes that could not be seen previously with PIC simulations. We observe a, to our knowledge, previously unreported secondary electron acceleration mechanism at low beam speeds. We believe that it is the result of parametric couplings to produce high phase velocity ESW’s which then trap electrons, accelerating them to higher energies. This allows electrons in our simulation study to achieve the injection energy required for Fermi acceleration, for beam speeds as low as 0.15c in unmagnetised plasma

Seizing stateless smuggling vessels on the Mediterranean High Seas

The EUNAVFOR MED anti-smuggling mission, Operation Sophia, ended in March 2020 and is largely viewed to have failed in its objective of ‘disrupting the business model’ of migrant smugglers in the Mediterranean region. The mission relied on purported enforcement powers in the 1982 United Nations Convention on the Law of the Sea and the 2000 Migrant Smuggling Protocol to seize and destroy stateless smuggling vessels on the high seas. Despite repeated claims to such powers by the European Union, neither treaty provides a strong jurisdictional basis for seizing stateless smuggling vessels outside territorial waters. However, ambiguous drafting in the Migrant Smuggling Protocol viably permits some claims to extraterritorial enforcement jurisdiction over stateless smuggling vessels on the high seas, and the European Union has relied on this ambiguity to tackle migrant smuggling. This article argues that the recent European Union anti-smuggling operations, most notably Operation Sophia, have reinterpreted the ambiguous term ‘appropriate measures’ in the Migrant Smuggling Protocol as permitting the states parties to exercise enforcement jurisdiction over stateless smuggling vessels at sea.<br/

Differentiating normal and problem gambling: a grounded theory approach.

A previous study (Ricketts &amp; Macaskill, 2003) delineated a theory of problem gambling based on the experiences of treatment seeking male gamblers and allowed predictions to be made regarding the processes that differentiate between normal and problem gamblers. These predictions are the focus of the present study, which also utilised a grounded theory approach, but with a sample of male high frequency normal gamblers. The findings suggest that there are common aspects of gambling associated with arousal and a sense of achievement. The use of gambling to manage negative emotional states differentiated normal and problem gambling. Perceived self-efficacy , emotion management skills and perceived likelihood of winning money back were intervening variables differentiating problem and normal gamblers.</p

Ethnic Women in Sơn La Province, Northern Vietnam: The Entrepreneurial Landscape

This article examines differences in the propensity to engage in entrepreneurial activities among ethnically diverse women in Sơn La Province, a disadvantaged and mountainous rural area of Vietnam. Propensity for entrepreneurialism is examined by focusing on (a) women’s use of technology, (b) experiences of financial difficulties, and (c) propensity for risk-taking. Analyzing surveys completed by 135 women, we find that plans to start a business are equally apparent among women from diverse ethnic groups. We establish a positive association between levels of entrepreneurialism (practicing entrepreneurs, intending entrepreneurs, and non-entrepreneurs) and the use of technology. However, we find no association between entrepreneurialism and access to finance/financial difficulties or risk-taking. Women from very small ethnic minorities often report never using the Internet, and they seek loans from private lenders who charge relatively high interest rates. Our findings suggest a need for greater government investment in rural areas to increase women’s access to and use of technology

Simple Nudges for Better Password Creation

Recent security breaches have highlighted the consequences of reusing passwords across online accounts. Recent guidance on password policies by the UK government recommend an emphasis on password length over an extended character set for generating secure but memorable passwords without cognitive overload. This paper explores the role of three nudges in creating website-specific passwords: financial incentive (present vs absent), length instruction (long password vs no instruction) and stimulus (picture present vs not present). Mechanical Turk workers were asked to create a password in one of these conditions and the resulting passwords were evaluated based on character length, resistance to automated guessing attacks, and time taken to create the password. We found that users created longer passwords when asked to do so or when given a financial incentive and these longer passwords were harder to guess than passwords created with no instruction. Using a picture nudge to support password creation did not lead to passwords that were either longer or more resistant to attacks but did lead to account-specific passwords

Mixed emotions to near-miss outcomes: a psychophysiological study with facial electromyography

Near-misses occur across many forms of gambling and are rated as unpleasant while simultaneously increasing the motivation to continue playing. On slot machines, the icon position relative to the payline moderates the effects of near-misses, with near-misses before the payline increasing motivation, and near-misses after the payline being rated as aversive. Near-misses are also known to increase physiological arousal compared to full-misses, but physiological measures to date have not been able to dissociate positive and negative emotional responses. The present study measured facial electromyography at the corrugator (brow) and zygomaticus (cheek) sites, as well as electrodermal activity (EDA), following gambling outcomes on a two-reel slot machine simulation in 77 novice gamblers. Behavioral data was collected using trial-by-trial ratings of motivation and valence. Wins were rated as more pleasant and increased motivation to continue playing, compared to non-win outcomes. Wins were also accompanied by increased EDA and zygomaticus activity. Near-misses after the payline were rated as more aversive than other non-wins, and this was accompanied by increased EDA and zygomaticus activity. Near-misses before the payline increased motivation to continue playing, and were accompanied by increased EDA. Thus, both subjective and physiological responses to near-misses differ for events falling either side of the payline. The ‘near-miss effect’ is not a unitary phenomenon. Facial EMG has differential sensitivity to positive and negative valence and may be a useful measure for future studies of gambling behavior

Potential role of fibroblast-like synoviocytes in joint damage induced by Brucella abortus infection through production and induction of matrix metalloproteinases

Arthritis is one of the most common complications of human brucellosis, but its pathogenic mechanisms have not been elucidated. Fibroblast-like synoviocytes (FLS) are known to be central mediators of joint damage in inflammatory arthritides through the production of matrix metalloproteinases (MMPs) that degrade collagen and of cytokines and chemokines that mediate the recruitment and activation of leukocytes. In this study we show that Brucella abortus infects and replicates in human FLS (SW982 cell line) in vitro and that infection results in the production of MMP-2 and proinflammatory mediators (interleukin-6 [IL-6], IL-8, monocyte chemotactic protein 1 [MCP-1], and granulocyte-macrophage colony-stimulating factor [GM-CSF]). Culture supernatants from Brucella-infected FLS induced the migration of monocytes and neutrophils in vitro and also induced these cells to secrete MMP-9 in a GM-CSF- and IL-6-dependent fashion, respectively. Reciprocally, culture supernatants from Brucella-infected monocytes and neutrophils induced FLS to produce MMP-2 in a tumor necrosis factor alpha (TNF-α)-dependent fashion. The secretion of proinflammatory mediators and MMP-2 by FLS did not depend on bacterial viability, since it was also induced by heat-killed B. abortus (HKBA) and by a model Brucella lipoprotein (L-Omp19). These responses were mediated by the recognition of B. abortus antigens through Toll-like receptor 2. The intra-articular injection of HKBA or L-Omp19 into the knee joint of mice resulted in the local induction of the proinflammatory mediators MMP-2 and MMP-9 and in the generation of a mixed inflammatory infiltrate. These results suggest that FLS, and phagocytes recruited by them to the infection focus, may be involved in joint damage during brucellar arthritis through the production of MMPs and proinflammatory mediators.Fil: Scian, Romina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "Profesor R. A. Margni"; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Barrionuevo, Paula. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "Profesor R. A. Margni"; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Giambartolomei, Guillermo Hernan. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "Profesor R. A. Margni"; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: de Simone, Emilio Adrian. Universidad de Buenos Aires. Facultad de Cs.veterinarias. Catedra de Fisiologia Animal; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "Profesor R. A. Margni"; ArgentinaFil: Vanzulli, Silvia I.. Academia Nacional de Medicina de Buenos Aires; ArgentinaFil: Fossati, Carlos Alberto. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "Profesor R. A. Margni"; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Baldi, Pablo Cesar. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "Profesor R. A. Margni"; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Delpino, María Victoria. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral "Profesor R. A. Margni"; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin

The effects on chronic periodontitis of a subgingivally-placed redox agent in a slow release device

Adjunctive chemical agents can reduce the need for meticulous plaque control. The aim of this investigation was to evaluate the periodontal treatment potential of subgingival application of the redox agent methylene blue in a slow release device. This randomized, single-blind, split-mouth study included 18 patients aged 35- 57 years, with chronic adult periodontitis, pocketing of at least 5mm and radiographic evidence of regular bone loss. All experimental sites received subgingival debridement at day 0. Test sites received 32% w/w methylene blue in the slow release device at days 0 and 28. Clinical examination and microbiological sampling were performed at days 0, 7, 28, 56 and 84. Clinical improvements were seen in both groups, but test sites showed consistently greater improvements, some of which were statistically significant (as determined by between-group comparisons utilising SNDs). Significant between-group differences in relation to baseline levels were seen in bleeding index at days 7 and 56, in probable pocket depth at day 56 and for the Perioscan BANA test at day 7. This pilot study thus showed that adjunctive methylene blue in a slow-release device can produce greater clinical and microbiological improvements than subgingival debridement alone.peer-reviewe

Cognitive and psychological science insights to improve climate change data visualization

Visualization of climate data plays an integral role in the communication of climate change findings to both expert and non-expert audiences. The cognitive and psychological sciences can provide valuable insights into how to improve visualization of climate data based on knowledge of how the human brain processes visual and linguistic information. We review four key research areas to demonstrate their potential to make data more accessible to diverse audiences: directing visual attention, visual complexity, making inferences from visuals, and the mapping between visuals and language. We present evidence-informed guidelines to help climate scientists increase the accessibility of graphics to non-experts, and illustrate how the guidelines can work in practice in the context of Intergovernmental Panel on Climate Change graphics

Osteochondral transplantation using autografts from the upper tibio-fibular joint for the treatment of knee cartilage lesions

Purpose Treatment of large cartilage lesions of the knee in weight-bearing areas is still a controversy and challenging topic. Autologous osteochondral mosaicplasty has proven to be a valid option for treatment but donor site morbidity with most frequently used autografts remains a source of concern. This study aims to assess clinical results and safety profile of autologous osteochondral graft from the upper tibio-fibular joint applied to reconstruct symptomatic osteochondral lesions of the knee. Methods Thirty-one patients (22 men and 9 women) with grade 4 cartilage lesions in the knee were operated by mosaicplasty technique using autologous osteochondral graft from the upper tibio-fibular joint, between 1998 and 2006. Clinical assessment included visual analog scale (VAS) for pain and Lysholm score. All patients were evaluated by MRI pre- and post-operatively regarding joint congruency as good, fair (inferior to 1 mm incongruence), and poor (incongruence higher than 1 mm registered in any frame). Donor zone status was evaluated according to specific protocol considering upper tibio-fibular joint instability, pain, neurological complications, lateral collateral ligament insufficiency, or ankle complaints. Results Mean age at surgery was 30.1 years (SD 12.2). In respect to lesion sites, 22 were located in weight-bearing area of medial femoral condyle, 7 in lateral femoral condyle, 1 in trochlea, and 1 in patella. Mean follow-up was 110.1 months (SD 23.2). Mean area of lesion was 3.3 cm 2 (SD 1.7), and a variable number of cylinders were used, mean 2.5 (SD 1.3). Mean VAS score improved from 47.1 (SD 10.1) to 20.0 (SD 11.5); p = 0.00. Similarly, mean Lysholm score increased from 45.7 (SD 4.5) to 85.3 (SD 7.0); p = 0.00. The level of patient satisfaction was evaluated, and 28 patients declared to be satisfied/very satisfied and would do surgery again, while 3 declared as unsatisfied with the procedure and would not submit to surgery again. These three patients had lower clinical scores and kept complaints related to the original problem but unrelated to donor zone. MRI score significantly improved at 18–24 months comparing with pre-operative (p = 0.004). No radiographic or clinical complications related to donor zone with implication in activity were registered. Conclusions This work corroborates that mosaicplasty technique using autologous osteochondral graft from the upper tibio-fibular joint is effective to treat osteochondral defects in the knee joint. No relevant complications related to donor zone were registered