Narrow Line Cooling and Momentum-Space Crystals

Narrow line laser cooling is advancing the frontier for experiments ranging from studies of fundamental atomic physics to high precision optical frequency standards. In this paper, we present an extensive description of the systems and techniques necessary to realize 689 nm 1S0 - 3P1 narrow line cooling of atomic 88Sr. Narrow line cooling and trapping dynamics are also studied in detail. By controlling the relative size of the power broadened transition linewidth and the single-photon recoil frequency shift, we show that it is possible to continuously bridge the gap between semiclassical and quantum mechanical cooling. Novel semiclassical cooling process, some of which are intimately linked to gravity, are also explored. Moreover, for laser frequencies tuned above the atomic resonance, we demonstrate momentum-space crystals containing up to 26 well defined lattice points. Gravitationally assisted cooling is also achieved with blue-detuned light. Theoretically, we find the blue detuned dynamics are universal to Doppler limited systems. This paper offers the most comprehensive study of narrow line laser cooling to date.Comment: 14 pages, 19 figure

Clinical- and cost-effectiveness of a nurse led self-management intervention to reduce emergency visits by people with epilepsy

People with chronic epilepsy (PWE) often make costly, and clinically unnecessary emergency department (ED) visits. Some do it frequently. No studies have examined interventions to reduce them. An intervention delivered by an epilepsy nurse specialist (ENS) might reduce visits. The rationale is it may optimize patients' self-management skills and knowledge of appropriate ED use. We examined such an intervention's clinical- and cost-effectiveness. Eighty-five adults with epilepsy were recruited from three London EDs with similar catchment populations. Forty-one PWE recruited from two EDs received treatment-as-usual (TAU) and formed the comparison group. The remaining 44 PWE were recruited from the ED of a hospital that had implemented a new ENS service for PWE attending ED. These participants formed the intervention group. They were offered 2 one-to-one sessions with an ENS, plus TAU. Participants completed questionnaires on health service use and psychosocial well-being at baseline, 6- and 12-month follow-up. Covariates were identified and adjustments made. Sixty-nine (81%) participants were retained at follow-up. No significant effect of the intervention on ED visits at 12 months or on other outcomes was found. However, due to less time as inpatients, the average service cost for intervention participants over follow-up was less than for TAU participants' (adjusted difference £558, 95% CI, −£2409, £648). Covariates most predictive of subsequent ED visits were patients' baseline feelings of stigmatization due to epilepsy and low confidence in managing epilepsy. The intervention did not lead to a reduction in ED use, but did not cost more, partly because those receiving the intervention had shorter hospital admissions. Our findings on long-term ED predictors clarifies what causes ED use, and suggests that future interventions might focus more on patients' perceptions of stigma and on their confidence in managing epilepsy. If addressed, ED visits might be reduced and efficiency-savings generated

Stimulation of shrimp (Penaeus monodon) hemocytes by lipopolysaccharide-like molecules derived from Novacq™

Immune stimulation through feed additives is a promising strategy that can help to combat disease in shrimp farming and reduce the use of antibiotics and other chemotherapeutics. The present study investigated the in vitro immunostimulatory effects of lipopolysaccharide (LPS)-like molecules isolated from the microbial based feed additive Novacq™ (N-LPS). The presence of LPS-like molecules was confirmed and quantified Novacq™ using a HEK-TLR4 reporter cell line. Primary hemocytes isolated from adult Penaeus monodon were used to measure the immunostimulatory of N-LPS compared with the control group that were treated with E. coli derived LPS (E-LPS). The N-LPS stimulated a rapid and significant induction of the phenoloxidase (PO) response in the hemocytes. The PO response increased with exposure time and LPS concentration and was significantly higher compared with an E. coli LPS (E-LPS) control. In addition, using gene expression data, we quantified the transcriptome response of the hemocytes at 15, 30 and 60 mins post stimulation. Compared with the controls, the N-LPS treated hemocytes had a significant up-regulation of genes involved in the immune system modulation and control at all time-points. Most noteworthy was the significant induction of transcripts that function as serine protease inhibitors (namely SERPINs), that regulate the overexpression of the PO system. Transcription factors from the Notch family which directly regulate the expression of many immune genes were also induced within the hemocytes. Additionally, we also saw a strong up-regulation of crustacean hyperglycemic hormone (CHH) transcripts, an important neuropeptide involved in immune function. Overall, the transcriptome profile of the hemocytes suggests that the LPS component of Novacq™ is highly immunostimulatory and generates a strong PO response in vitro. The subsequent transcriptional response appears to be directed towards preventing further activation of the PO system most likely in an attempt to limit cytoxicity to the host. Our study highlights the immunostimulatory ability of Novacq™ and provides further evidence of the positive health benefits this microbial based feed additive can have in shrimp.</p

The place of strategic environmental assessment in the privatised electricity industry

The private sector has given relatively little attention to the emergence of strategic environmental assessment (SEA); even recently privatised utilities, where SEA might be deemed particularly appropriate, and whose activities are likely to fall within the scope of the European Union SEA Directive, have shown less interest than might be expected. However, the global trend towards the privatisation of state-owned enterprises makes the adaptation of SEA towards these industries all the more pressing. This paper addresses the place that SEA might take within the electricity sector, taking the privatised UK electricity industry as an example. Particular challenges are posed by the radical restructuring of the industry, designed to introduce competitive behaviour, making the development of comprehensive SEA processes problematic, and requiring SEA to be placed in the context of corporate environmental policy and objectives.</p

Ground-truthing daily and lunar patterns of coral reef fish call rates on a US Virgin Island reef

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ferguson, S., Jensen, F., Hyer, M., Noble, A., Apprill, A., & Mooney, T. Ground-truthing daily and lunar patterns of coral reef fish call rates on a US Virgin Island reef. Aquatic Biology, 31, (2022): 77–87, https://doi.org/10.3354/ab00755.Coral reefs comprise some of the most biodiverse habitats on the planet. These ecosystems face a range of stressors, making quantifying community assemblages and potential changes vital to effective management. To understand short- and long-term changes in biodiversity and detect early warning signals of decline, new methods for quantifying biodiversity at scale are necessary. Acoustic monitoring techniques have proven useful in observing species activities and biodiversity on coral reefs through aggregate approaches (i.e. energy as a proxy). However, few studies have ground-truthed these acoustic analyses with human-based observations. In this study, we sought to expand these passive acoustic methods by investigating biological sounds and fish call rates on a healthy reef, providing a unique set of human-confirmed, labeled acoustic observations. We analyzed acoustic data from Tektite Reef, St. John, US Virgin Islands, over a 2 mo period. A subset of acoustic files was manually inspected to identify recurring biotic sounds and quantify reef activity throughout the day. We found a high variety of acoustic signals in this soundscape. General patterns of call rates across time conformed to expectations, with dusk and dawn showing important and significantly elevated peaks in soniferous fish activity. The data reflected high variability in call rates across days and lunar phases. Call rates did not correspond to sound pressure levels, suggesting that certain call types may drive crepuscular trends in sound levels while lower-level critical calls, likely key for estimating biodiversity and behavior, may be missed by gross sound level analyses.This research was funded by the National Science Foundation Biological Oceanography award 1536782. The experiments were conducted under National Park Service Scientific Research and Collecting Permits VIIS-2016-SCI-0017-20, and we thank the Park staff for their support

Critical Phenomena in Neutron Stars I: Linearly Unstable Nonrotating Models

We consider the evolution in full general relativity of a family of linearly unstable isolated spherical neutron stars under the effects of very small, perturbations as induced by the truncation error. Using a simple ideal-fluid equation of state we find that this system exhibits a type-I critical behaviour, thus confirming the conclusions reached by Liebling et al. [1] for rotating magnetized stars. Exploiting the relative simplicity of our system, we are able carry out a more in-depth study providing solid evidences of the criticality of this phenomenon and also to give a simple interpretation of the putative critical solution as a spherical solution with the unstable mode being the fundamental F-mode. Hence for any choice of the polytropic constant, the critical solution will distinguish the set of subcritical models migrating to the stable branch of the models of equilibrium from the set of subcritical models collapsing to a black hole. Finally, we study how the dynamics changes when the numerically perturbation is replaced by a finite-size, resolution independent velocity perturbation and show that in such cases a nearly-critical solution can be changed into either a sub or supercritical. The work reported here also lays the basis for the analysis carried in a companion paper, where the critical behaviour in the the head-on collision of two neutron stars is instead considered [2].Comment: 15 pages, 9 figure