Generating a ‘Clean’ pi0 Spectrum in STAR

The STAR detector at Brookhaven National Laboratory’s Relativistic Heavy Ion Collider uses polarized proton collisions to investigate the origin of the proton spin, using measurements such as neutral pion (π0) asymmetries. STAR’s Endcap Electromagnetic Calorimeter (EEMC) is especially useful for detecting photons from π0 decays at forward-angle scattering from ≈15 to ≈40 degrees above the beam direction. We identify π0’s by constructing invariant mass spectra from these photons. Large background contributions are present in these spectra and distort the true value of the π0 invariant mass. By applying constraints (cuts) on parameters such as the opening angle of the photons in the reconstructed pair, decay vertex position, photon energy, and energy asymmetry, I have been able to produce a ‘clean’ π0 spectrum with little background using the data from 2006. In the future, a ‘clean’ π0 invariant mass spectrum can provide an avenue to calibrate the EEMC against the known pion mass. This method combined with our current calibration methodologies could improve understanding of the EEMC response, critical to our ability to investigate π0 spin asymmetries. The results, along with a comparison to simulated Monte Carlo data, will be presented

An Event-by-Event Comparison of Clustering Algorithms for Photon Detection in the STAR Endcap Calorimeter

The STAR detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory uses polarized proton collisions to determine the origin of the proton spin, using measurements such as neutral pion asymmetries. The Endcap Electromagnetic Calorimeter (EEMC) in the STAR detector is especially useful for detecting photons from π° decays at forward angles. This latter measurement is obtained from the Shower Maximum Detector (SMD) in the EEMC where narrow crossed scintillator strips measure the energy deposited in them and can be used to identify the location of the photon shower. The electromagnetic shower most often deposits energy in a small number of adjacent strips that collectively form a “cluster.” This work has focused on a qualitative and quantitative comparison of two different clustering algorithms that were developed to reliably identify π° events and to effectively discriminate against background cluster selection that produces false π° signals. This comparative analysis will be presented and the strengths and weaknesses of the algorithms will be discussed

Bedside Handoff in the Emergency Department

Background A standardized approach to bedside handoff improves nurse and patient satisfaction as well as quality outcomes. Objectives To compare the preference for bedside handoff in the emergency department post implementation by analyzing nursing surveys and Press Ganey data. Design A mixed method pilot study. Settings A not-for-profit community-based safety net hospital which is Magnet designated. ED is a level 3 trauma center with 60,000 visits annually. Participants ED nurses (n=52) and adult patients (n=86) Methods A pre and post implementation survey that utilized the 5-point Likert scale was given to nursing staff in the emergency department. Questions were asked two weeks prior to implementation and education roll out to determine baseline ratings from nurses. Post implementation survey was given after 10 weeks to compare with pre survey. Press Ganey data was collected and analyzed to determine if bedside handoff improved the patient’s perception of care provided by nursing staff. Results Patient satisfaction scores increased in overall percentile rank and in overall nursing post implementation. Rounding in the ED by management showed an increase in patient satisfaction with handoff process feeling as though they were kept informed of their plan of care. Pre and post implementation surveys had an increase in all aspects except for report time was appropriate with post implementation. Conclusion In this study, it was determined that nurses and patients preferred bedside handoff compared to report at the bedside. Nursing staff reported an increase in thoroughness of handoff as well as increased accountability and respect between shifts. Patient satisfaction scores increased with patients reporting an increase in nursing communication, information about plan of care, family members were kept updated

The Cost Of Privacy: Riley v. California’s Impact on Cell Phone Searches

Riley v. California is the United States Supreme Court’s first attempt to regulate the searches of cell phones by law enforcement. The 2014 unanimous decision requires a warrant for all cell phone searches incident to arrest absent an emergency. This work summarizes the legal precedent and analyzes the limitations and practical implications of the ruling. General guidelines for members of the criminal justice system at all levels consistent with the Supreme Court’s decision are provided

Distributional range, ecology, and mating system of the Cape mole-rat (Georychus capensis) family Bathyergidae

Abstract: Interpopulation variation in life-history patterns are influenced by intrinsic and extrinsic factors. Life-history patterns have been intensely studied in the eusocial African bathyergid species, largely neglecting the solitary species. Of these solitary genera, the Cape mole-rat (Georychus capensis (Pallas, 1778)) is endemic to South Africa with a disjunct distribution across its range. Knowledge regarding this species is rudimentary; therefore, this study aimed to investigate the current distribution of the species with particular attention to common ecological variables, differences in body size between localities and sexes, as well as its reproduction and mating system. Georychus is a habitat specialist restricted to specific ecological areas. A lack of sexual size dimorphism and correlation between male testis size and number of females in the population, suggests a polygynous mating system, facilitated by the spatial distribution of the sexes. A positive relationship between male testes size and percentage of females in populations sampled suggests that larger sperm reserves (i.e., larger testes) are required in populations with a higher percentage of females. In addition, mating variables (testicular size and litter size) are linked to ecological factors (elevation, aridity, soil type, and vegetation type) that could impact mate searching, mating success, and food resources

Sexual Signalling in Propithecus verreauxi: Male “Chest Badge” and Female Mate Choice

Communication, an essential prerequisite for sociality, involves the transmission of signals. A signal can be defined as any action or trait produced by one animal, the sender, that produces a change in the behaviour of another animal, the receiver. Secondary sexual signals are often used for mate choice because they may inform on a potential partner's quality. Verreaux's sifaka (Propithecus verreauxi) is characterized by the presence of two different morphs of males (bimorphism), which can show either a stained or clean chest. The chest becomes stained by secretions of the sternal gland during throat marking (rubbing throat and chest on a vertical substrate while smearing the scent deposition). The role of the chest staining in guiding female mate choice was previously hypothesized but never demonstrated probably due to the difficulty of observing sifaka copulations in the wild. Here we report that stained-chested males had a higher throat marking activity than clean-chested males during the mating season, but not during the birth season. We found that females copulated more frequently with stained-chested males than the clean-chested males. Finally, in agreement with the biological market theory, we found that clean-chested males, with a lower scent-releasing potential, offered more grooming to females. This “grooming for sex” tactic was not completely unsuccessful; in fact, half of the clean-chested males copulated with females, even though at low frequency. In conclusion, the chest stain, possibly correlated with different cues targeted by females, could be one of the parameters which help females in selecting mates

Mating First, Mating More: Biological Market Fluctuation in a Wild Prosimian

In biology, economics, and politics, distributive power is the key for understanding asymmetrical relationships and it can be obtained by force (dominance) or trading (leverage). Whenever males cannot use force, they largely depend on females for breeding opportunities and the balance of power tilts in favour of females. Thus, males are expected not only to compete within their sex-class but also to exchange services with the opposite sex. Does this mating market, described for humans and apes, apply also to prosimians, the most ancestral primate group? To answer the question, we studied a scent-oriented and gregarious lemur, Propithecus verreauxi (sifaka), showing female dominance, promiscuous mating, and seasonal breeding. We collected 57 copulations involving 8 males and 4 females in the wild (Berenty Reserve, South Madagascar), and data (all occurrences) on grooming, aggressions, and marking behaviour. We performed the analyses via exact Spearman and matrix correlations. Male mating priority rank correlated with the frequency of male countermarking over female scents but not with the proportion of fights won by males over females. Thus, males competed in an olfactory tournament more than in an arena of aggressive encounters. The copulation frequency correlated neither with the proportion of fights won by males nor with the frequency of male countermarking on female scents. Male-to-female grooming correlated with female-to-male grooming only during premating. Instead, in the mating period male-to-female grooming correlated with the copulation frequency. In short, the biological market underwent seasonal fluctuations, since males bargained grooming for sex in the mating days and grooming for itself in the premating period. Top scent-releasers gained mating priority (they mated first) and top groomers ensured a higher number of renewed copulations (they mated more). In conclusion, males maximize their reproduction probability by adopting a double tactic and by following market fluctuations

Demography and Life Histories of Sympatric Patas Monkeys, Erythrocebus patas, and Vervets, Cercopithecus aethiops, in Laikipia, Kenya

Mortality patterns are thought to be strong selective forces on life history traits, with high adult mortality and low immature mortality favoring early and rapid reproduction. Patas monkeys (Erythrocebus patas) have the highest potential rates of population increase for their body size of any haplorhine primate because they reproduce both earlier and more often. We report here 10 yr of comparative demographic data on a population of patas monkeys and a sympatric population of vervet monkeys (Cercopithecus aethiops), a closely related species differing in aspects of social system, ecology, and life history. The data reveal that 1) adult female patas monkeys have significantly higher mortality than adult female vervets; 2) infant mortality in patas monkeys is relatively low compared to the norm for mammals because it is not significantly different from that of adult female patas monkeys; and 3) infant mortality is significantly higher than adult female mortality in vervets. For both species, much of the mortality could be attributed to predation. An epidemic illness was also a major contributor to the mortality of adult female patas monkeys whereas chronic exposure to pathogens in a cold and damp microenvironment may have contributed to the mortality of infant vervets. Both populations experienced large fluctuations during the study period. Our results support the prediction from demographic models of life history evolution that high adult mortality relative to immature mortality selects for early maturation

Neutral pion cross section and spin asymmetries at intermediate pseudorapidity in polarized proton collisions at √s = 200 GeV

The differential cross section and spin asymmetries for neutral pions produced within the intermediate pseudorapidity range 0.8 < η < 2.0 in polarized proton-proton collisions at √s = 200  GeV are presented. Neutral pions were detected using the end cap electromagnetic calorimeter in the STAR detector at RHIC. The cross section was measured over a transverse momentum range of 5 < p[subscript T] < 16  GeV/c and is found to agree with a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry A[subscript LL] is measured in the same pseudorapidity range and spans a range of Bjorken-x down to x ≈ 0.01. The measured A[subscript LL] is consistent with model predictions for varying degrees of gluon polarization. The parity-violating asymmetry A[subscript L] is also measured and found to be consistent with zero. The transverse single-spin asymmetry A[subscript N] is measured over a previously unexplored kinematic range in Feynman-x and p[subscript T]. Such measurements may aid our understanding of the onset and kinematic dependence of the large asymmetries observed at more forward pseudorapidity (η ≈ 3) and their underlying mechanisms. The A[subscript N] results presented are consistent with a twist-3 model prediction of a small asymmetry over the present kinematic range.United States. Dept. of Energy. Office of Nuclear PhysicsUnited States. Dept. of Energy. Office of High Energy PhysicsNational Science Foundation (U.S.