Spectroscopy of the enigmatic short-period cataclysmic variable IR Com in an extended low state

We report the occurrence of a deep low state in the eclipsing short-period cataclysmic variable IR Com, lasting more than two years. Spectroscopy obtained in this state shows the system as a detached white dwarf plus low-mass companion, indicating that accretion has practically ceased. The spectral type of the companion derived from the SDSS spectrum is M6-7, somewhat later than expected for the orbital period of IR Com. Its radial velocity amplitude, K_2=419.6+-3.4 km/s, together with the inclination of 75-90deg implies 0.8Msun<Mwd<1.0Msun. We estimate the white dwarf temperature to be ~15000K, and the absence of Zeeman splitting in the Balmer lines rules out magnetic fields in excess of ~5 MG. IR Com still defies an unambiguous classification, in particular the occurrence of a deep, long low state is so far unique among short-period CVs that are not strongly magnetic.Comment: Revised version, MNRAS Letters in pres

Cortisol levels are positively associated with pup-feeding rates in male meerkats

In societies of cooperative vertebrates, individual differences in contributions to offspring care are commonly substantial. Recent attempts to explain the causes of this variation have focused on correlations between contributions to care and the protein hormone prolactin, or the steroid hormone testosterone. However, such studies have seldom considered the importance of other hormones or controlled for non-hormonal factors that are correlative with both individual hormone levels and contributions to care. Using multivariate statistics, we show that hormone levels explain significant variation in contributions to pup-feeding by male meerkats, even after controlling for non-hormonal effects. However, long-term contributions to pup provisioning were significantly and positively correlated with plasma levels of cortisol rather than prolactin, while plasma levels of testosterone were not related to individual patterns of pup-feeding. Furthermore, a playback experiment that used pup begging calls to increase the feeding rates of male helpers gave rise to parallel increases in plasma cortisol levels, whilst prolactin and testosterone levels remained unchanged. Our findings confirm that hormones can explain significant amounts of variation in contributions to offspring feeding, and that cortisol, not prolactin, is the hormone most strongly associated with pup-feeding in cooperative male meerkats

Extraction of Coupling Information From Z′→jjZ' \to jj

An analysis by the ATLAS Collaboration has recently shown, contrary to popular belief, that a combination of strategic cuts, excellent mass resolution, and detailed knowledge of the QCD backgrounds from direct measurements can be used to extract a signal in the $Z' \to jj$ channel in excess of $6\sigma$ for certain classes of extended electroweak models. We explore the possibility that the data extracted from $Z$ dijet peak will have sufficient statistical power as to supply information on the couplings of the $Z'$ provided it is used in conjunction with complimentary results from the $Z' \to \ell^+ \ell^-$ `discovery' channel. We show, for a 1 TeV $Z'$ produced at the SSC, that this technique can provide a powerful new tool with which to identify the origin of $Z'$'s.Comment: 24 pages, 9 figures(available on request), LaTex, ANL-HEP-PR-93-1

Estimating flexibility preferences to resolve temporal scheduling conflicts in activity-based modelling

This paper presents a novel activity-based demand model that combines an optimisation framework for continuous temporal scheduling decisions (i.e. activity timings and durations) with traditional discrete choice models for non-temporal choice dimensions (i.e. activity participation, number and type of tours, and destinations). The central idea of our approach is that individuals resolve temporal scheduling conflicts that arise from overlapping activities, e.g. needing to work and desiring to shop at the same time, in order to maximise their daily utility. Flexibility parameters capture behavioural preferences that penalise deviations from desired timings. This framework has three advantages over existing activity-based modelling approaches: (i) the time conflicts between different temporal scheduling decisions including the activity sequence are treated jointly; (ii) flexibility parameters follow a utility maximisation approach; and (iii) the framework can be used to estimate and simulate a city-scale case study in reasonable time. We introduce an estimation routine that allows flexibility parameters to be estimated using real-world observations as well as a simulation routine to efficiently resolve temporal conflicts using an optimisation model. The framework is applied to the full-time workers of a synthetic population for the city of Lausanne, Switzerland. We validate the model results against reported schedules. The results demonstrate the capabilities of our approach to reproduce empirical observations in a real-world case study

Do team processes really have an effect on clinical performance? A systematic literature review

Summary There is a growing literature on the relationship between team processes and clinical performance. The purpose of this review is to summarize these articles and examine the impact of team process behaviours on clinical performance. We conducted a literature search in five major databases. Inclusion criteria were: English peer-reviewed papers published between January 2001 and May 2012, which showed or tried to show (i) a statistical relationship of a team process variable and clinical performance or (ii) an improvement of a performance variable through a team process intervention. Study quality was assessed using predefined quality indicators. For every study, we calculated the relevant effect sizes. We included 28 studies in the review, seven of which were intervention studies. Every study reported at least one significant relationship between team processes or an intervention and performance. Also, some non-significant effects were reported. Most of the reported effect sizes were large or medium. The study quality ranged from medium to high. The studies are highly diverse regarding the specific team process behaviours investigated and also regarding the methods used. However, they suggest that team process behaviours do influence clinical performance and that training results in increased performance. Future research should rely on existing theoretical frameworks, valid, and reliable methods to assess processes such as teamwork or coordination and focus on the development of adequate tools to assess process performance, linking them with outcomes in the clinical settin

The effects of recruitment to direct predator cues on predator responses in meerkats

Behavioral responses of animals to direct predator cues (DPCs; e.g., urine) are common and may improve their survival. We investigated wild meerkat (Suricata suricatta) responses to DPCs by taking an experimental approach. When meerkats encounter a DPC they often recruit group members by emitting a call type, which causes the group members to interrupt foraging and approach the caller. The aim of this study was to identify the qualities of olfactory predator cues, which affect the strength of response by meerkats, and determine the benefits of responses to such cues. Experimental exposure to dog (Canis lupus) urine as a DPC revealed that the recruited individuals increased vigilance to fresh urine in comparison to older urine, whereas a higher quantity of urine did not induce such an effect. Both freshness and higher quantities increased the proportion of group members recruited. These results indicate that recruitment might play a crucial role in correctly assessing the current level of danger and that recruiting might facilitate group decision making. To test the prediction that the reaction to a DPC enhances early predator response, we presented a DPC of a predator and a control cue of a herbivore, and each time simultaneously moved a full-mounted caracal (Caracal caracal) in the vicinity of the group. Meerkats responded earlier to the caracal when the DPC was presented, indicating that the response to a DPC facilitates predator response and that they use information from the cue that reliably reflects the risk in the current momen

Suggested reference ranges in clinical chemistry for apparently healthy males and females of Pakistan.

Abstract Seven hundred and eighty six apparently healthy males (418) and females (368) aged 0-69 years were randomly selected for estimation of reference ranges of 24 serum analytes at the clinical chemistry laboratory of The Ago Khon University Hospital (AKUH). Of the total study samples, 56% (439/786) were in the poediatric age group (0-14 years) and 44% (347/786) in the adult (1 5_60 years) group. Beckman Astra Ideal Autoanalyzer was used for all the estimations. Moon and standard deviations (SD) were calculated for each of the age groups. Reference ranges were calculated following standard methods of the International Federation of Clinical Chemistry (IFCC) and International Committee far Standardization in Haematology (ICSH) (JPMA 43:113, 1993)

Adaptation in anaesthesia team coordination in response to a simulated critical event and its relationship to clinical performance

Background Recent studies in anaesthesia and intensive care indicate that a team's ability to adapt its coordination activities to changing situational demands is crucial for effective teamwork and thus, safe patient care. This study addresses the relationship between adaptation of team coordination and markers of clinical performance in response to a critical event, particularly regarding which types of coordination activities are used and which team member engages in those coordination activities. Methods Video recordings of 15 two-person anaesthesia teams (anaesthesia trainee plus anaesthesia nurse) performing a simulated induction of general anaesthesia were coded, using a structured observation system for coordination activities. The simulation involved a critical event—asystole during laryngoscopy. Clinical performance was assessed using two separate reaction times related to the critical event. Results Analyses of variance revealed a significant effect of the critical event on team coordination: after the occurrence of the asystole, team members adapted their coordination activities by spending more time on information management—a specific type of coordination activity (F1,28=15.17, P=0.001). No significant effect was found for task management. The increase in information management was related to faster decisions regarding how to respond to the critical event, but only for trainees and not for nurses. Conclusions Our findings support the claim that adaptation of coordination activities is related to improved team performance in healthcare. Moreover, adaptation and its relationship to team performance were found to vary with regard to type of coordination activities and team membe