1,023 research outputs found
Effects of Gamma Ray Bursts in Earth Biosphere
We continue former work on the modeling of potential effects of Gamma Ray
Bursts on Phanerozoic Earth. We focus on global biospheric effects of ozone
depletion and show a first modeling of the spectral reduction of light by NO2
formed in the stratosphere. We also illustrate the current complexities
involved in the prediction of how terrestrial ecosystems would respond to this
kind of burst. We conclude that more biological field and laboratory data are
needed to reach even moderate accuracy in this modelingComment: Accepted for publication in Astrophysics & Space Scienc
Pharmaceutical vehicles for vaginal and rectal administration of anti-hiv microbicide nanosystems
Prevention strategies play a key role in the fight against HIV/AIDS. Vaginal and rectal microbicides hold great promise in tackling sexual transmission of HIV-1, but effective and safe products are yet to be approved and made available to those in need. While most efforts have been placed in finding and testing suitable active drug candidates to be used in microbicide development, the last decade also saw considerable advances in the design of adequate carrier systems and formulations that could lead to products presenting enhanced performance in protecting from infection. One strategy demonstrating great potential encompasses the use of nanosystems, either with intrinsic antiviral activity or acting as carriers for promising microbicide drug candidates. Polymeric nanoparticles, in particular, have been shown to be able to enhance mucosal distribution and retention of promising antiretroviral compounds. One important aspect in the development of nanotechnology-based microbicides relates to the design of pharmaceutical vehicles that allow not only convenient vaginal and/or rectal administration, but also preserve or even enhance the performance of nanosystems. In this manuscript, we revise relevant work concerning the selection of vaginal/rectal dosage forms and vehicle formulation development for the administration of microbicide nanosystems. We also pinpoint major gaps in the field and provide pertinent hints for future work.This work was supported by Programa Gilead GÉNESE, Gilead Portugal (refs. PGG/046/2015 and PGG/002/2016). This article is a result of the project NORTE-01-0145-FEDER-000012, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work was financed by FEDER-Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020-Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT-Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274), and also Partnership Agreement PT2020 UID/QUI/50006/2013-POCI/01/0145/FEDER/007265. J.G. gratefully acknowledges FCT for financial support (SFRH/BD/140271/2018 scholarship)
Theta dependence of CP^9 model
We apply to the model two recently proposed numerical techniques for
simulation of systems with a theta term. The algorithms, successfully tested in
the strong coupling limit, are applied to the weak coupling region. The results
agree and errors have been evaluated and are at % level. The results scale well
with the renormalization group equation and show that, for in presence
of a theta term, CP symmetry is spontaneously broken at in the
continuum limit.Comment: 4 pages, 4 figure
Recommended from our members
Mass casualty events: what to do as the dust settles?
Care during mass casualty events (MCE) has improved during the last 15 years. Military and civilian collaboration has led to partnerships which augment the response to MCE. Much has been written about strategies to deliver care during an MCE, but there is little about how to transition back to normal operations after an event. A panel discussion entitled The Day(s) After: Lessons Learned from Trauma Team Management in the Aftermath of an Unexpected Mass Casualty Event at the 76th Annual American Association for the Surgery of Trauma meeting on September 13, 2017 brought together a cadre of military and civilian surgeons with experience in MCEs. The events described were the First Battle of Mogadishu (1993), the Second Battle of Fallujah (2004), the Bagram Detention Center Rocket Attack (2014), the Boston Marathon Bombing (2013), the Asiana Flight 214 Plane Crash (2013), the Baltimore Riots (2015), and the Orlando Pulse Night Club Shooting (2016). This article focuses on the lessons learned from military and civilian surgeons in the days after MCEs
Survival of the Immature Stages of the Malaria Vectors Anopheles pseudopunctipennis and Anopheles argyritarsis (Diptera: Culicidae) in Northwestern Argentina
In order to optimally time the application of control measures to reduce populations of malaria vectors, program managers need to know precisely when the vulnerable larval stage will be most abundant at each specific breeding site. Therefore at 4 different breeding sites of the malaria vectors, Anopheles pseudopunctipennis Theobald and Anopheles argyritarsis Robineau-Desvoidy in northwestern Argentina, we recorded the calendar dates during spring and summer when different life stages appeared, and in each of these 2 seasons, we measured the duration of each life stage and the probability that it would transition to the subsequent stage or die. Larval samples were collected during the spring and summer of 2008-2009 at 4 localities in northwestern Argentina. These larvae were reared individually in plastic containers in which the volume of water was kept constant, temperature and photoperiod were controlled, and a standard amount of food was provided each day. The data were analyzed by multistate models, a nonparametric model of survival without covariates, a survival model with covariates, a Cox-type survival model with specific co-variates, and models of reduced rank. We collected 1,643 larvae of which 1,404 reached adulthood. Of these 1,119 were An. pseudopunctipennis, and 285 were An. argyritarsis. Both An. pseudopunctipennis and An. argyritarsis were abundant in autumn (55.3% and 66.7%, respectively). Considerably more individuals transitioned from larvae to pupae than from pupae to adults. The probability of an individual remaining in the larval stage for the first 2 days was close to 100% and then decreased. The transition from the larval stage to death was significant in the summer. The breeding site at Rosario de la Frontera exhibited a particularly significant effect on the transition from the larval stage to death, i.e., greatly increased larval mortality. The results obtained in the present study are substantial contributions to the bionomics of An. pseudopunctipennis and An. argyritarsis. According to our results, mosquito source management programs should be focused on the larval stage during the summer season and principally at Rosario de la Frontera River. These actions could substantially reduce the production of the adult vectors and potentially reduce transmission of malaria in northwestern Argentina.Para optimizar el tiempo de aplicación de medidas tendientes a reducir las poblaciones de vectores de la malaria, los directores de programas necesitan saber con precisión cuando el estado larval vulnerable será más abundante en cada sitio específico de cría. Por lo tanto, en 4 diferentes sitios de cría de los vectores de la malaria, Anopheles pseudopunctipennis Theobald y Anopheles argyritarsis Robineau - Desvoidy, en el noroeste de Argentina, registramos las fechas durante la primavera y el verano cuando los diferentes estados de vida aparecieron, y en cada una de estas 2 estaciones climáticas, medimos la duración de cada estado de vida y la probabilidad que había para la transición al siguiente estado o para morir. Se recogieron muestras de larvas durante la primavera y el verano de 2008-2009 en 4 localidades en el noroeste de Argentina. Estas larvas fueron criadas individualmente en envases de plástico en la que el volumen de agua se mantuvo constante, la temperatura y el fotoperíodo se controlaron, y una cantidad estándar de la comida se proporcionó cada día. Los datos se analizaron mediante modelos multiestados, un modelo no paramétrico de supervivencia sin co-variables, un modelo de supervivencia con co-variables, un modelo de supervivencia de tipo Cox con co-variables específicas y un modelo de rango reducido. Se recolectaron 1.643 larvas, de las cuales 1.404 llegaron a las formas adultas, identificándose 1.119 como An. pseudopunctipennis y 285 como An. argyritarsis. Tanto Anopheles pseudopunctipennis como An. argyritarsis fueron abundantes en el otoño (55,32% y 66,67%, respectivamente). Considerablemente más individuos pasaron de ser larvas a pupas que de pupas a adultos. La probabilidad de un individuo de permanecer en el estado larval en los primeros 2 días fue cercana al 100%, disminuyendo luego. La transición de larva a muerte fue significativa en el verano. El sitio de cría de Rosario de la Frontera exhibió un efecto significativo en la transición del estado larval a la muerte, es decir, aumentó en gran medida la mortalidad de las larvas. Los resultados obtenidos en el presente estudio son importantes contribuciones a la bionomía de An. pseudopunctipennis y An. argyritarsis. Según nuestros resultados, los programas de manejo de criaderos de mosquitos deben centrarse en el estado larval durante el verano y principalmente en el río Rosario de la Frontera. Estas acciones podrían reducir sustancialmente la producción de los vectores adultos y potencialmente reducir la transmisión de la malaria en el noroeste de Argentina.Fil: Galante, Guillermina B.. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; ArgentinaFil: Santana, Mirta. Universidad Nacional de Tucuman. Facultad de Medicina; ArgentinaFil: Veggiani Aybar, Cecilia Adriana. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dantur Juri, Maria Julia. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto Superior de Entomología; Argentina. Universidad Nacional de Chilecito; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Co2 capture and electrochemical conversion using superbasic [p-66614]-[124triz]
The ionic liquid trihexyltetradecylphosphonium 1,2,4- triazolide, [P66614][124Triz], has been shown to chemisorb CO2 through equimolar binding of the carbon dioxide with the 1,2,4-triazolide anion. This leads to a possible new, low energy pathway for the electrochemical reduction of carbon dioxide to formate and syngas at low overpotentials, utilizing this reactive ionic liquid media. Herein, an electrochemical investigation of water and carbon dioxide addition to the [P66614][124Triz] on gold and platinum working electrodes is reported. Electrolysis measurements have been performed using CO2 saturated [P66614][124Triz] based solutions at -0.9 V and -1.9 V on gold and platinum electrodes. The effects of the electrode material on the formation of formate and syngas using these solutions are presented and discussed18338940
Altered states of consciousness caused by a mindfulness-based programme up to a year later: Results from a randomised controlled trial
Background: Mindfulness-based programmes (MBPs) have shown beneficial effects on mental health. There is emerging evidence that MBPs may also be associated with marked deviations in the subjective experience of waking consciousness. We aimed to explore whether MBPs can have a causal role in different types of such states. Methods: We conducted a pragmatic randomised controlled trial (ACTRN12615001160527). University of Cambridge students without severe mental illness were randomised to an 8-week MBP plus mental health support as usual (SAU), or to SAU alone. We adapted the Altered States of Consciousness Rating Scale (OAV, 0–100-point range) to assess spontaneous experiences in daily life, and included it as a post-hoc secondary outcome at the end of the one-year follow-up questionnaire. Two-part model analyses compared trial arms, and estimated dose-response effects of formal (meditation) and informal (daily activities) mindfulness practice during the year. Sensitivity analyses correcting for multiple comparisons were conducted. Results: We randomised 670 participants; 205 (33%) completed the OAV. In comparison with SAU, MBP participants experienced unity more frequently and intensively (two-part marginal effect (ME) = 6.26 OAV scale points, 95% confidence interval (CI) = 2.24, 10.27, p = 0.006, Cohen’s d = 0.33) and disembodiment more frequently (ME = 4.84, 95% CI = 0.86, 8.83, p = 0.019, Cohen’s d = 0.26). Formal practice predicted spiritual, blissful and unity experiences, insightfulness, disembodiment, and changed meanings. Informal practice predicted unity and blissful experiences. Trial arm comparisons and informal practice effects lost significance after corrections for multiple comparisons, but formal practice dose-response effects remained significant. Conclusions: Results provide a novel suggestion of causal links between mindfulness practice and specific altered states of consciousness. To optimise their impact, practitioners and teachers need to anticipate and handle them appropriately. Future studies need to confirm findings and assess mechanisms and clinical implications
Application of Nanostructures and Metamaterials in Accelerator Physics
Carbon-based nanostructures and metamaterials offer extraordinary mechanical and opto-electrical properties, which make them suitable for applications in diverse fields, including, for example, bioscience, energy technology and quantum computing. In the latest years, important R&D efforts have been made to investigate the potential use of graphene and carbon-nanotube (CNT) based structures to manipulate and accelerate particle beams. In the same way, the special interaction of graphene and CNTs with charged particles and electromagnetic radiation might open interesting possibilities for the design of compact coherent radiation sources, and novel beam diagnostics techniques as well. This paper gives an overview of novel concepts based on nanostructures and metamaterials with potential application in the field of accelerator physics. Several examples are shown and future prospects discussed
Vortex liquid entanglement in twinned YBa_2Cu_3O_7 /Y_2BaCuO_5 composite superconductors
The angular dependence of the in-plane resistivity ρ(T,H, θ) of melt textured YBa_2Cu_3O_7/Y_2BaCuO_5 composites has been measured in a large range of magnetic fields and temperatures and from them, the intrinsic anisotropy of the superconducting state has been verified following the anisotropic Ginzburg-Landau approach. The influence of correlated defects like twin boundaries and quenched disorder generated by Y_2BaCuO_5 precipitates on the pinning behavior of these composites in the liquid vortex state is analyzed, and the corresponding phase diagram is determined and compared to that of twinned single crystals. We show that the irreversibility line displays an upwards shift due to twin boundary pinning enabling to define a ''quenched'' Bose glass transition. A new region in the vortex liquid state is identified where twin boundary pinning defines a partially entangled liquid vortex state characterized by a short-range c-axis vortex coherence. The transition to the entangled liquid phase is experimentally determined. The relevance of this depinning line and its unique position with respect to twinned single crystals is discussed. [S0163- 1829(99)01741-5]
- …