281 research outputs found
Dzyaloshinskii-Moriya interaction in transport through single molecule transistors
The Dzyaloshinskii-Moriya interaction is shown to result in a canting of
spins in a single molecule transistor. We predict non-linear transport
signatures of this effect induced by spin-orbit coupling for the generic case
of a molecular dimer. The conductance is calculated using a master equation and
is found to exhibit a non-trivial dependence on the magnitude and direction of
an external magnetic field. We show how three-terminal transport measurements
allow for a determination of the coupling-vector characterizing the
Dzyaloshinskii-Moriya interaction. In particular, we show how its orientation,
defining the intramolecular spin chirality, can be probed with ferromagnetic
electrodes
Longitudinal association of physical activity during pregnancy with maternal and infant outcomes: Findings from the Australian longitudinal study of women’s health
Background:
Physical activity has known benefits during pregnancy; however, the optimum volume of physical activity through the different stages of pregnancy is not well known.
Objectives:
The aims of this study were to investigate the associations of physical activity volume in pregnant women in each trimester of pregnancy with maternal and infant outcomes.
Design:
The study involved 1657 pregnant women from the Australian Longitudinal Study on Women’s Health, who completed surveys from 2006 to 2012 (aged 28–39 years).
Methods:
Women reported being in either the first, second or third trimester of pregnancy. Women were grouped into four groups according to their self-reported physical activity during pregnancy: (1) Nil (0–<33.3 MET.min/week), (2) Low (33.3–<500 MET.min/week), (3) Moderate (500–<1000 MET.min/week) and (4) High (⩾1000 MET.min/week). Women who reported their physical activity during pregnancy completed a survey within three years after the birth, relating to outcomes associated with pregnancy and childbirth (gestational diabetes, hypertension, and antenatal depression and anxiety) and infant outcomes (birthweight and prematurity).
Results:
There was no association of physical activity in any trimester with infant birthweight, prematurity, gestational diabetes, hypertension or antenatal depression. Antenatal anxiety was less prevalent in women who reported low (1.7%) or moderate (1.1%) physical activity than in those who reported no activity (4.7%; p = 0.01).
Conclusion:
Different amounts of physical activity during pregnancy were not associated with the measured adverse health outcomes. However, low and moderate amounts of physical activity were associated with reduced incidence of antenatal anxiety
Management Accountant's Role and Functions in the Enterprise Resource Planning Environment - Author's Own Research into Enterprises in Poland
This article seeks to answer whether the implementation of an ERP system has an effect on the management accountant's tasks and functions, especially in the field of performance measurement and internal reporting. The ERP impacts on the controller's role in the organization will be evaluated using field studies on six enterprises owned by multinational corporations. The question that should be asked here is whether controller's functions and tasks will also be unaffected.Celem badania jest próba odpowiedzi na pytanie czy zastosowanie zintegrowanego systemu informatycznego w przedsiębiorstwie zmienia zadania i funkcje specjalisty do spraw rachunkowości zarządczej. Na podstawie studium przypadku sześciu przedsiębiorstw będących częścią koncernów międzynarodowych zostaje dokonana ocena wpływu zastosowania ERP na rolę kontrolera w organizacji. Autor odpowiada również na pytanie czy w funkcjach i zadaniach kontrolera nie zaobserwowane zostaną zmiany w związku z implementacją ERP
Re: ‘Response to Letter to the Editor on “Galectin-3, Carotid Plaque Vulnerability, and Potential Effects of Statin Therapy”’
The Nernst effect and the boundaries of the Fermi liquid picture
Following the observation of an anomalous Nernst signal in cuprates, the
Nernst effect was explored in a variety of metals and superconductors during
the past few years. This paper reviews the results obtained during this
exploration, focusing on the Nernst response of normal quasi-particles as
opposed to the one generated by superconducting vortices or by short-lived
Cooper pairs. Contrary to what has been often assumed, the so-called Sondheimer
cancelation does not imply a negligible Nernst response in a Fermi liquid. In
fact, the amplitude of the Nernst response measured in various metals in the
low-temperature limit is scattered over six orders of magnitude. According to
the data, this amplitude is roughly set by the ratio of electron mobility to
Fermi energy in agreement with the implications of the semi-classical transport
theory.Comment: Final version, Topical review for JPC
What are the odds? Identifying factors related to competitive success in powerlifting
Background: The ability for athletes to gain a competitive advantage over their opponents is well recognised. At times, this advantage may be considered a marginal gain. However, in the context of competition, marginal advantages may be the difference between winning and losing. This investigation explores how competition factors influence the odds of competitive success (i.e. winning) in powerlifting (PL) to assist athletes and coaches in achieving a competitive advantage. Methods: A cross-sectional, retrospective analysis of competition data from raw/classic, Australian powerlifting competitions 2010–2019 was conducted. Data included 10,599 competition entries (males: n = 6567 [62%], females: n = 4032 [38%]). Independent t-tests were used to compare continuous data between sexes or winners and non-winners at an event. Cohen’s d and the 95% confidence interval (d [95% CI]) were calculated. Univariate odds of winning an event based on independent variables (age [irrespective of category], sex, body weight and weight of first lift attempt [regardless of success]), were assessed by separate simple logistic regression. Results: When compared to males, the odds of winning for females were 50% greater (OR [95% CI] 1.500 [1.384, 1.625]; P \u3c 0.001). Athletes who had larger first lift attempts (Squat: + 7.0 kg P \u3c 0.001, Bench Press: + 3.2 kg P \u3c 0.001, and Deadlift: + 6.1 kg P \u3c 0.001and competed for a longer period (winners: 401 vs non-winners: 304 days, P \u3c 0.001) had an increased likelihood winning. Age was associated with increased odds of success for males (OR [95% CI] 1.014 [1.009, 1.019], P \u3c 0.001) per additional year of age for males, but not females (P = 0.509). Conclusions: Multiple factors appear to contribute to the likelihood of winning a PL competition. These results may help coaches to develop competition and training strategies that optimise athletes’ likelihood of competitive success in PL
Observation of spin-selective tunneling in SiGe nanocrystals
Spin-selective tunneling of holes in SiGe nanocrystals contacted by
normal-metal leads is reported. The spin selectivity arises from an interplay
of the orbital effect of the magnetic field with the strong spin-orbit
interaction present in the valence band of the semiconductor. We demonstrate
both experimentally and theoretically that spin-selective tunneling in
semiconductor nanostructures can be achieved without the use of ferromagnetic
contacts. The reported effect, which relies on mixing the light and heavy
holes, should be observable in a broad class of quantum-dot systems formed in
semiconductors with a degenerate valence band.Comment: 8 pages, 5 figure
Identification of financial statement fraud in Greece by using computational intelligence techniques
The consequences of financial fraud are an issue with far-reaching for investors, lenders, regulators, corporate sectors and consumers. The range of development of new technologies such as cloud and mobile computing in recent years has compounded the problem. Manual detection which is a traditional method is not only inaccurate, expensive and time-consuming but also they are impractical for the management of big data. Auditors, financial institutions and regulators have tried to automated processes using statistical and computational methods. This paper presents comprehensive research in financial statement fraud detection by using machine learning techniques with a particular focus on computational intelligence (CI) techniques. We have collected a sample of 2469 observations since 2002 to 2015. Research gap was identified as none of the existing researchers address the association between financial statement fraud and CI-based detection algorithms and their performance, as reported in the literature. Also, the innovation of this research is that the selection of data sample is aimed to create models which will be capable of detecting the falsification in financial statements
Material-specific gap function in the high-temperature superconductors
We present theoretical arguments and experimental support for the idea that
high-Tc superconductivity can occur with s-wave, d-wave, or mixed-wave pairing
in the context of a magnetic mechanism. The size and shape of the gap is
different for different materials. The theoretical arguments are based on the
t-J model as derived from the Hubbard model so that it necessarily includes
three-site terms. We argue that this should be the basic minimal model for
high-Tc systems. We analyze this model starting with the dilute limit which can
be solved exactly, passing then to the Cooper problem which is numerically
tractable, then ending with a mean field approach. It is found that the
relative stability of s-wave and d-wave depends on the size and the shape of
the Fermi surface. We identify three striking trends. First, materials with
large next-nearest-neighbor hopping (such as YBa(2)Cu(3)O(7-x)) are nearly pure
d-wave, whereas nearest-neighbor materials (such as La(2-x)Sr(x)CuO(4)) tend to
be more s-wave-like. Second, low hole doping materials tend to be pure d-wave,
but high hole doping leads to s-wave. Finally, the optimum hole doping level
increases as the next-nearest-neighbor hopping increases. We examine the
experimental evidence and find support for this idea that gap function in the
high-temperature superconductors is material-specific.Comment: 20 pages; requires revtex.sty v3.0, epsf.sty; includes 6 EPS figures;
Postscript version also available at
http://lifshitz.physics.wisc.edu/www/koltenbah/papers/gapfunc2.ps . This
version contains an extensive amount of new work including theoretical
background, an additional mean field treatment with new figures, and a more
thorough experimental surve
Joule-assisted silicidation for short-channel silicon nanowire devices
We report on a technique enabling electrical control of the contact
silicidation process in silicon nanowire devices. Undoped silicon nanowires
were contacted by pairs of nickel electrodes and each contact was selectively
silicided by means of the Joule effect. By a realtime monitoring of the
nanowire electrical resistance during the contact silicidation process we were
able to fabricate nickel-silicide/silicon/nickel- silicide devices with
controlled silicon channel length down to 8 nm.Comment: 6 pages, 4 figure
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