Compound equation developed for postnatal growth of birds and mammals

Compound growth equation was developed in which the rate of this linear growth process is regarded as proportional to the mass already attained at any instant by an underlying Gompertz process. This compound growth model was fitted to the growth data of a variety of birds and mammals of both sexes

SU(N) Fermions in a One-Dimensional Harmonic Trap

We conduct a theoretical study of SU(N) fermions confined by a one-dimensional harmonic potential. Firstly, we introduce a new numerical approach for solving the trapped interacting few-body problem, by which one may obtain accurate energy spectra across the full range of interaction strengths. In the strong-coupling limit, we map the SU(N) Hamiltonian to a spin-chain model. We then show that an existing, extremely accurate ansatz - derived for a Heisenberg SU(2) spin chain - is extendable to these N-component systems. Lastly, we consider balanced SU(N) Fermi gases that have an equal number of particles in each spin state for N=2, 3, 4. In the weak- and strong-coupling regimes, we find that the ground-state energies rapidly converge to their expected values in the thermodynamic limit with increasing atom number. This suggests that the many-body energetics of N-component fermions may be accurately inferred from the corresponding few-body systems of N distinguishable particles.Comment: 15 pages, 6 figure

X-ray properties of UV-selected star forming galaxies at z~1 in the Hubble Deep Field North

We present an analysis of the X-ray emission from a large sample of ultraviolet (UV) selected, star forming galaxies with 0.74<z<1.32 in the Hubble Deep Field North (HDF-N) region. By excluding all sources with significant detected X-ray emission in the 2 Ms Chandra observation we are able to examine the properties of galaxies for which the emission in both UV and X-ray is expected to be predominantly due to star formation. Stacking the X-ray flux from 216 galaxies in the soft and hard bands produces significant detections. The derived mean 2-10 keV rest-frame luminosity is 2.97+/-0.26x10^(40) erg/s, corresponding to an X-ray derived star formation rate (SFR) of 6.0+/-0.6 Msolar/yr. Comparing the X-ray value with the mean UV derived SFR, uncorrected for attenuation, we find that the average UV attenuation correction factor is \~3. By binning the galaxy sample according to UV magnitude and colour, correlations between UV and X-ray emission are also examined. We find a strong positive correlation between X-ray emission and rest-frame UV emission. A correlation between the ratio of X-ray-to-UV emission and UV colour is also seen, such that L(X)/L(UV) increases for redder galaxies. Given that X-ray emission offers a view of star formation regions that is relatively unaffected by extinction, results such as these can be used to evaluate the effects of dust on the UV emission from high-z galaxies. For instance we derive a relationship for estimating UV attenuation corrections as a function of colour excess. The observed relation is inconsistent with the Calzetti et al. (2000) reddening law which over predicts the range in UV attenuation corrections by a factor of ~100 for the UV selected z~1 galaxies in this sample (abridged).Comment: 10 pages, 7 figures, accepted for publication in MNRA

Preparing Nurses for Roles in End-of-Life Decision-Making

Abstract PREPARING NURSES FOR ROLES IN END-OF-LIFE DECISION-MAKING by Susan K. Laird, MSN, RN Purpose: This DNP quality improvement project provided an educational intervention for senior nursing students to facilitate learning better ways to support patients and families dealing with end-of-life decision-making. Background/Significance: Aging patients often present with multiple co-morbidities, yet fewer than 37% of patients have advance directives in place and have made their wishes known to family members who will be faced with end-of-life decisions. On the front lines with dying patients and family members, nurses are poised to provide information and support to this population, yet they are not adequately prepared to do so. PICO: Will education and training in end-of-life issues improve nursing students’ knowledge and confidence so that they will be better prepared to provide care for patients and families facing end-of-life decision-making when they enter the workforce? Methods: For this quasi-experimental study, participants were given a pre-test, a classroom presentation of six original educational modules developed by the DNP student, followed by a post-test, a questionnaire and a participant evaluation. The pre/post-tests were identical, containing questions addressing attitudes and knowledge. The modules addressed cultural issues, family dynamics, and communications skills. Results: Fifty-four students participated in the class. Participants demonstrated statistically significant increases in knowledge and changes in attitudes after the educational intervention. Implications: It is the goal of this study to provide and evaluate educational materials and trainings which potentially contribute to the increase of knowledge for nursing students and for nurses already in their practice settings. By providing a broader exposure to challenges facing patients and their families facing end-of-life issues earlier in and throughout the nursing curriculum, nursing students may enter the clinical setting with increased confidence and improved comfort levels in their own abilities which may in turn lead to better overall patient care

To Trust or Not: The Effects of Monitoring Intensity on Discretionary Effort, Honesty, and Problem Solving Ability

Managerial accounting researchers and practitioners are increasingly concerned with the effects of formal organizational controls on agent behavior. This three-paper dissertation extends this line of research by experimentally examining the effects of monitoring intensity on three important work behaviors which, generally, are not directly observable by the organizational control system: discretionary effort, problem solving ability, and honesty. Together, these studies help fill a gap in the managerial accounting literature by examining the relationship between the monitoring environment and agent behavior. The principal-agent theory of the firm suggests that tighter monitoring by the principal will increase the agent’s work effort at best, and have no effect at worst. However, the psychology literature suggests that monitoring may actually reduce effort by “crowding out” an individual’s intrinsic motivation to perform unmeasured or unrewarded work related tasks. In Paper 1, I test for the crowding out effect of monitoring and find mixed results. In Paper 2, I investigate the effects of monitoring intensity on various aspects of problem solving ability and creativity. Past research suggests that strict environmental controls can have detrimental effects on creative thinking. I extend this line of literature by investigating how monitoring affects an individual’s problem solving ability. In general, I find that monitoring intensity is negatively associated with problem solving ability. In Paper 3, I investigate how monitoring intensity affects an individual’s propensity toward dishonesty using a 3x2 experimental design where the participants are given a simple task, with a monetary reward based on performance, in one of the three monitoring treatments—trust, human monitoring, or electronic monitoring—and in one of two outcome reporting regimes—self-report or verified. I find an inverted-U shape relationship between monitoring intensity and dishonesty, where dishonesty is highest under human monitoring. Organizations are increasing their use of all types of surveillance and controls, and, in general, trust is increasingly discouraged within organizations. These papers add to the managerial accounting literature by shedding light on how different monitoring environments can change human behavior. This line of research can only increase in importance as regulation increases and monitoring technology becomes more advanced, reliable, and accessible

Negations in syllogistic reasoning: Evidence for a heuristic–analytic conflict

An experiment utilizing response time measures was conducted to test dominant processing strategies in syllogistic reasoning with the expanded quantifier set proposed by Roberts (2005). Through adding negations to existing quantifiers it is possible to change problem surface features without altering logical validity. Biases based on surface features such as atmosphere, matching, and the probability heuristics model (PHM; Chater & Oaksford, 1999; Wetherick & Gilhooly, 1995) would not be expected to show variance in response latencies, but participant responses should be highly sensitive to changes in the surface features of the quantifiers. In contrast, according to analytic accounts such as mental models theory and mental logic (e.g., Johnson-Laird & Byrne, 1991; Rips, 1994) participants should exhibit increased response times for negated premises, but not be overly impacted upon by the surface features of the conclusion. Data indicated that the dominant response strategy was based on a matching heuristic, but also provided evidence of a resource-demanding analytic procedure for dealing with double negatives. The authors propose that dual-process theories offer a stronger account of these data whereby participants employ competing heuristic and analytic strategies and fall back on a heuristic response when analytic processing fails

Quantum transport in carbon nanotubes

Carbon nanotubes are a versatile material in which many aspects of condensed matter physics come together. Recent discoveries, enabled by sophisticated fabrication, have uncovered new phenomena that completely change our understanding of transport in these devices, especially the role of the spin and valley degrees of freedom. This review describes the modern understanding of transport through nanotube devices. Unlike conventional semiconductors, electrons in nanotubes have two angular momentum quantum numbers, arising from spin and from valley freedom. We focus on the interplay between the two. In single quantum dots defined in short lengths of nanotube, the energy levels associated with each degree of freedom, and the spin-orbit coupling between them, are revealed by Coulomb blockade spectroscopy. In double quantum dots, the combination of quantum numbers modifies the selection rules of Pauli blockade. This can be exploited to read out spin and valley qubits, and to measure the decay of these states through coupling to nuclear spins and phonons. A second unique property of carbon nanotubes is that the combination of valley freedom and electron-electron interactions in one dimension strongly modifies their transport behaviour. Interaction between electrons inside and outside a quantum dot is manifested in SU(4) Kondo behavior and level renormalization. Interaction within a dot leads to Wigner molecules and more complex correlated states. This review takes an experimental perspective informed by recent advances in theory. As well as the well-understood overall picture, we also state clearly open questions for the field. These advances position nanotubes as a leading system for the study of spin and valley physics in one dimension where electronic disorder and hyperfine interaction can both be reduced to a very low level.Comment: In press at Reviews of Modern Physics. 68 pages, 55 figure

Carbon nanotube quantum dots on hexagonal boron nitride

We report the fabrication details and low-temperature characteristics of the first carbon nanotube (CNT) quantum dots on flakes of hexagonal boron nitride (hBN) as substrate. We demonstrate that CNTs can be grown on hBN by standard chemical vapor deposition and that standard scanning electron microscopy imaging and lithography can be employed to fabricate nanoelectronic structures when using optimized parameters. This proof of concept paves the way to more complex devices on hBN, with more predictable and reproducible characteristics and electronic stability.Comment: 4 pages, 4 figure