6,677 research outputs found
Promoting positive experiences: Students perceptions and future intentions from attending a Student Organization and Competition Fair
This study explores the role of extra-curricular activities among students. In particular, this study focuses on investigating the effects of student organization and external competition fair on creating students\u27 motivation. Flow and Student Engagement theory supports students\u27 active involvement on campus. The finding highlights the importance of extra-curricular activities on students overall
The significant role of post-pairing male behavior on the evolution of male preferences and female traits
Existing sexual selection theory postulates that a sufficiently large variation in female fecundity or other direct benefits are fundamental for generating male mate choice. In this study, we suggest that, in addition to pre-pairing preferences, choosy males can also have different post-pairing behaviors, a factor which has been comparatively overlooked by previous studies. We found that both male preferences and female traits could evolve much more easily than previously expected when the choosy males that paired with unpreferred females would allocate more efforts to seeking additional post-pairing mating opportunities. Furthermore, a costly female trait could evolve when there was a trade-off between seeking additional mating and paternal care investment within social pair for choosy males. Finally, a costly male preference and a costly female trait might still evolve and reach a stable polymorphic state in the population, which might give rise to a high variability in male choice and female traits in nature. We suggest that male mate choice may be even more common than expected, which needs to be verified empiricall
The Paradox of Institutional Trust and Entrepreneurship in Transitional Countries
The relationship between institutional trust and entrepreneurship is not straightforward but is intertwined with social context. This study explores this relationship by estimating the relationship between entrepreneurship and institutional trust together with a set of individual social demographics and the country of residence in 27 transitional countries in Eastern Europe and countries of the former Soviet Union using the data of the 2016 Life in Transition Survey (LiTS). The analytical framework in this study is that individuals make their decisions in choosing the type of employment by weighing the level of institutional trust in their communities, a set of democratic factors and social indicators.The results of our 2SLS estimations indicate a consistent negative association between institutional trust and entrepreneurship for all the sub-datasets. However, this cannot be interpreted as evidence for the negative effect of institutional trust on entrepreneurship. Given our analytical framework, this counter common-sense phenomenon would be interpreted as when the institutional trust was high, individuals would rather choose to have a paid job instead of running their own business in these transitional countries. This study provides evidence of how far these countries have gone on the path of transition three decades after the transition
Fine-grained Complexity Meets IP = PSPACE
In this paper we study the fine-grained complexity of finding exact and
approximate solutions to problems in P. Our main contribution is showing
reductions from exact to approximate solution for a host of such problems.
As one (notable) example, we show that the Closest-LCS-Pair problem (Given
two sets of strings and , compute exactly the maximum with ) is equivalent to its approximation version
(under near-linear time reductions, and with a constant approximation factor).
More generally, we identify a class of problems, which we call BP-Pair-Class,
comprising both exact and approximate solutions, and show that they are all
equivalent under near-linear time reductions.
Exploring this class and its properties, we also show:
Under the NC-SETH assumption (a significantly more relaxed
assumption than SETH), solving any of the problems in this class requires
essentially quadratic time.
Modest improvements on the running time of known algorithms
(shaving log factors) would imply that NEXP is not in non-uniform
.
Finally, we leverage our techniques to show new barriers for
deterministic approximation algorithms for LCS.
At the heart of these new results is a deep connection between interactive
proof systems for bounded-space computations and the fine-grained complexity of
exact and approximate solutions to problems in P. In particular, our results
build on the proof techniques from the classical IP = PSPACE result
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Chemodiversity in spp.: A literature review on comparative germplasm studies with focus on iridoids and other terpenes
Negative longitudinal magnetoresistance in GaAs quantum wells
Negative longitudinal magnetoresistances (NLMRs) have been recently observed
in a variety of topological materials and often considered to be associated
with Weyl fermions that have a defined chirality. Here we report NLMRs in
non-Weyl GaAs quantum wells. In the absence of a magnetic field the quantum
wells show a transition from semiconducting-like to metallic behaviour with
decreasing temperature. We observed pronounced NLMRs up to 9 Tesla at
temperatures above the transition and weak NLMRs in low magnetic fields at
temperatures close to the transition and below 5 K. The observed NLMRs show
various types of magnetic field behaviour resembling those reported in
topological materials. We attribute them to microscopic disorder and use a
phenomenological three-resistor model to account for their various features.
Our results showcase a new contribution of microscopic disorder in the
occurrence of novel phenomena. They may stimulate further work on tuning
electronic properties via disorder/defect nano-engineering
Grain boundary effects on magnetotransport in bi-epitaxial films of LaSrMnO
The low field magnetotransport of LaSrMnO (LSMO) films
grown on SrTiO substrates has been investigated. A high qualtity LSMO film
exhibits anisotropic magnetoresistance (AMR) and a peak in the
magnetoresistance close to the Curie temperature of LSMO. Bi-epitaxial films
prepared using a seed layer of MgO and a buffer layer of CeO display a
resistance dominated by grain boundaries. One film was prepared with seed and
buffer layers intact, while a second sample was prepared as a 2D square array
of grain boundaries. These films exhibit i) a low temperature tail in the low
field magnetoresistance; ii) a magnetoconductance with a constant high field
slope; and iii) a comparably large AMR effect. A model based on a two-step
tunneling process, including spin-flip tunneling, is discussed and shown to be
consistent with the experimental findings of the bi-epitaxial films.Comment: REVTeX style; 14 pages, 9 figures. Figure 1 included in jpeg format
(zdf1.jpg); the eps was huge. Accepted to Phys. Rev.
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