Pulsation period variations in the RRc Lyrae star KIC 5520878

Learned et. al. proposed that a sufficiently advanced extra-terrestrial civilization may tickle Cepheid and RR Lyrae variable stars with a neutrino beam at the right time, thus causing them to trigger early and jogging the otherwise very regular phase of their expansion and contraction. This would turn these stars into beacons to transmit information throughout the galaxy and beyond. The idea is to search for signs of phase modulation (in the regime of short pulse duration) and patterns, which could be indicative of intentional, omnidirectional signaling. We have performed such a search among variable stars using photometric data from the Kepler space telescope. In the RRc Lyrae star KIC 5520878, we have found two such regimes of long and short pulse durations. The sequence of period lengths, expressed as time series data, is strongly auto correlated, with correlation coefficients of prime numbers being significantly higher ($p=99.8$\%). Our analysis of this candidate star shows that the prime number oddity originates from two simultaneous pulsation periods and is likely of natural origin. Simple physical models elucidate the frequency content and asymmetries of the KIC 5520878 light curve. Despite this SETI null result, we encourage testing other archival and future time-series photometry for signs of modulated stars. This can be done as a by-product to the standard analysis, and even partly automated.Comment: Accepted for publication in ApJ. 49 pages, 16 figure

Cladoceran birth and death rates estimates

I. Birth and death rates of natural cladoceran populations cannot be measured directly. Estimates of these population parameters must be calculated using methods that make assumptions about the form of population growth. These methods generally assume that the population has a stable age distribution. 2. To assess the effect of variable age distributions, we tested six egg ratio methods for estimating birth and death rates with data from thirty-seven laboratory populations of Daphnia pulicaria. The populations were grown under constant conditions, but the initial age distributions and egg ratios of the populations varied. Actual death rates were virtually zero, so the difference between the estimated and actual death rates measured the error in both birth and death rate estimates. 3. The results demonstrate that unstable population structures may produce large errors in the birth and death rates estimated by any of these methods. Among the methods tested, Taylor and Slatkin's formula and Paloheimo's formula were most reliable for the experimental data. 4. Further analyses of three of the methods were made using computer simulations of growth of age-structured populations with initially unstable age distributions. These analyses show that the time interval between sampling strongly influences the reliability of birth and death rate estimates. At a sampling interval of 2.5 days (equal to the duration of the egg stage), Paloheimo's formula was most accurate. At longer intervals (7.5–10 days), Taylor and Slatkin's formula which includes information on population structure was most accurate

Dimensional structure and correlates of posttraumatic stress symptoms following suspected acute coronary syndrome

Background Posttraumatic stress disorder (PTSD) is a heterogeneous construct, and some have suggested that PTSD triggered by acute coronary syndrome (ACS) may differ from PTSD due to prototypical traumas. Methods We conducted the first examination of the latent structure of PTSD symptoms after suspected ACS in 399 adults in the REactions to Acute Care and Hospitalization (REACH) study, an observational cohort study of patients recruited from the emergency department during evaluation for ACS. Using confirmatory factor analysis, we compared the 4-factor dysphoria, 4-factor numbing, and 5-factor dysphoric arousal models of PTSD. Results Although all models fit well, the dysphoria model was selected as the best-fitting model. Further, there was measurement invariance of the dysphoria model by sex. PTSD dimensions evidenced differential associations with indicators of threat perception during ACS evaluation and adherence to cardioprotective medication. Limitations One limitation of this investigation is the use of self-report measures. In addition, only one-third of the sample was diagnosed with ACS at discharge; the remaining participants received diagnoses such as chest pain without a cardiac diagnosis, another symptom/disease process (e.g., hypertensive chronic kidney disease), or another cardiac disease. Conclusions Findings suggest that suspected ACS-related PTSD symptoms are best-represented by a 4-factor structure distinguishing between specific (e.g., re-experiencing) and non-specific (dysphoria) symptoms of PTSD that has received support in the broader PTSD literature

Pharmaceutical care for elderly patients shared between community pharmacists and general practitioners: A randomised evaluation. RESPECT (Randomised Evaluation of Shared Prescribing for Elderly people in the Community over Time) [ISRCTN16932128]

Background: This trial aims to investigate the effectiveness and cost implications of 'pharmaceutical care' provided by community pharmacists to elderly patients in the community. As the UK government has proposed that by 2004 pharmaceutical care services should extend nationwide, this provides an opportunity to evaluate the effect of pharmaceutical care for the elderly. Design: The trial design is a randomised multiple interrupted time series. We aim to recruit 700 patients from about 20 general practices, each associated with about three community pharmacies, from each of the five Primary Care Trusts in North and East Yorkshire. We shall randomise the five resulting groups of practices, pharmacies and patients to begin pharmaceutical care in five successive phases. All five will act as controls until they receive the intervention in a random sequence. Until they receive training community pharmacists will provide their usual dispensing services and so act as controls. The community pharmacists and general practitioners will receive training in pharmaceutical care for the elderly. Once trained, community pharmacists will meet recruited patients, either in their pharmacies (in a consultation room or dispensary to preserve confidentiality) or at home. They will identify drug-related issues/problems, and design a pharmaceutical care plan in conjunction with both the GP and the patient. They will implement, monitor, and update this plan monthly. The primary outcome measure is the 'Medication Appropriateness Index'. Secondary measures include adverse events, quality of life, and patient knowledge and compliance. We shall also investigate the cost of pharmaceutical care to the NHS, to patients and to society as a whole.published_or_final_versio

Iso-osmotic regulation of nitrate accumulation in lettuce (Lactuca sativa L.)

Concerns about possible health hazards arising from human consumption of lettuce and other edible vegetable crops with high concentrations of nitrate have generated demands for a greater understanding of processes involved in its uptake and accumulation in order to devise more sustainable strategies for its control. This paper evaluates a proposed iso-osmotic mechanism for the regulation of nitrate accumulation in lettuce (Lactuca sativa L.) heads. This mechanism assumes that changes in the concentrations of nitrate and all other endogenous osmotica (including anions, cations and neutral solutes) are continually adjusted in tandem to minimise differences in osmotic potential of the shoot sap during growth, with these changes occurring independently of any variations in external water potential. The hypothesis was tested using data from six new experiments, each with a single unique treatment comprising a separate combination of light intensity, N source (nitrate with or without ammonium) and nitrate concentration carried out hydroponically in a glasshouse using a butterhead lettuce variety. Repeat measurements of plant weights and estimates of all of the main soluble constituents (nitrate, potassium, calcium, magnesium, organic anions, chloride, phosphate, sulphate and soluble carbohydrates) in the shoot sap were made at intervals from about 2 weeks after transplanting until commercial maturity, and the data used to calculate changes in average osmotic potential in the shoot. Results showed that nitrate concentrations in the sap increased when average light levels were reduced by between 30 and 49 % and (to a lesser extent) when nitrate was supplied at a supra-optimal concentration, and declined with partial replacement of nitrate by ammonium in the external nutrient supply. The associated changes in the proportions of other endogenous osmotica, in combination with the adjustment of shoot water content, maintained the total solute concentrations in shoot sap approximately constant and minimised differences in osmotic potential between treatments at each sampling date. There was, however, a gradual increase in osmotic potential (ie a decline in total solute concentration) over time largely caused by increases in shoot water content associated with the physiological and morphological development of the plants. Regression analysis using normalised data (to correct for these time trends) showed that the results were consistent with a 1:1 exchange between the concentrations of nitrate and the sum of all other endogenous osmotica throughout growth, providing evidence that an iso-osmotic mechanism (incorporating both concentration and volume regulation) was involved in controlling nitrate concentrations in the shoot

Psychological climates in action learning sets: A manager’s perspective

Action Learning (AL) is often viewed as a process that facilitates professional learning through the creation of a positive psychological climate (Marquart, 2000; Schein, 1979). An psychological climate that fosters an environment in which learning set members feel psychologically safe enough to reflect upon both the successes, and failures in their professional life without any form of repercussion. However, there has been little attention given to the ways that that psychological climate develops, and the differing facets that create that climate. In response to such deficit, this paper reports the outcomes of interviews with eleven managers, all of whom are former AL set members on their experiences of action learning set membership. Drawing upon an interpretivist philosophy, the paper explores the key themes that emerged from the analysis of those interviews. The analysis serves to illustrate the differing facets that collectively contribute creation of a positive psychological climate that is conducive for learning. Analysis points to the relative importance of such facets as: trust, honesty, vulnerability, reciprocity, confidentiality and personal disclosure, all of which have the capacity to lead to a positive psychological climate in action learning sets. This paper is useful for developing an understanding of the differing facets in AL sets that create a psychological climate conducive for learning. As such, it has utility for action learning facilitators, set members, academics and educational consultants

A systematic review investigating fatigue, psychological and cognitive impairment following TIA and minor stroke:protocol paper

Approximately 20,000 people have a transient ischemic attack (TIA) and 23,375 have a minor stroke in England each year. Fatigue, psychological and cognitive impairments are well documented post-stroke. Evidence suggests that TIA and minor stroke patients also experience these impairments; however, they are not routinely offered relevant treatment. This systematic review aims to: (1) establish the prevalence of fatigue, anxiety, depression, post-traumatic stress disorder (PTSD) and cognitive impairment following TIA and minor stroke and to investigate the temporal course of these impairments; (2) explore impact on quality of life (QoL), change in emotions and return to work; (3) identify where further research is required and to potentially inform an intervention study

A Transcriptomic Signature of Mouse Liver Progenitor Cells

Liver progenitor cells (LPCs) can proliferate extensively, are able to differentiate into hepatocytes and cholangiocytes, and contribute to liver regeneration. The presence of LPCs, however, often accompanies liver disease and hepatocellular carcinoma (HCC), indicating that they may be a cancer stem cell. Understanding LPC biology and establishing a sensitive, rapid, and reliable method to detect their presence in the liver will assist diagnosis and facilitate monitoring of treatment outcomes in patients with liver pathologies. A transcriptomic meta-analysis of over 400 microarrays was undertaken to compare LPC lines against datasets of muscle and embryonic stem cell lines, embryonic and developed liver (DL), and HCC. Three gene clusters distinguishing LPCs from other liver cell types were identified. Pathways overrepresented in these clusters denote the proliferative nature of LPCs and their association with HCC. Our analysis also revealed 26 novel markers, LPC markers, including Mcm2 and Ltbp3, and eight known LPC markers, including M2pk and Ncam. These markers specified the presence of LPCs in pathological liver tissue by qPCR and correlated with LPC abundance determined using immunohistochemistry. These results showcase the value of global transcript profiling to identify pathways and markers that may be used to detect LPCs in injured or diseased liver