548 research outputs found
Specialized mechanoreceptor systems in rodent glabrous skin
Rodents use their forepaws to actively interact with their tactile environment. Studies on the physiology and anatomy of glabrous skin that makes up the majority of the forepaw are almost non-existent in the mouse. Here we developed a preparation to record from single sensory fibers of the forepaw and compared anatomical and physiological receptor properties to those of the hind paw glabrous and hairy skin. We found that the mouse forepaw skin is equipped with a very high density of mechanoreceptors; > 3 fold more than hind paw glabrous skin. In addition, rapidly adapting mechanoreceptors that innervate Meissner's corpuscles of the forepaw were several-fold more sensitive to slowly moving mechanical stimuli compared to their counterparts in the hind paw glabrous skin. All other mechanoreceptors types as well as myelinated nociceptors had physiological properties that were invariant regardless of which skin area they occupied. We discovered a novel D-hair receptor innervating a small group of hairs in the middle of the hind paw glabrous skin in mice. These glabrous skin D-hair receptors were direction sensitive albeit with an orientation sensitivity opposite to that described for hairy skin D-hair receptors. Glabrous skin hairs do not occur in all rodents, but are present in North American and African rodent species that diverged more than 65 million years ago. The function of these specialized hairs is unknown, but they are nevertheless evolutionarily very ancient. Our study reveals novel physiological specializations of mechanoreceptors in the glabrous skin that likely evolved to facilitate tactile exploration. This article is protected by copyright. All rights reserved
A theoretical scheme for generation of Gazeau-Klauder coherent states via intensity-dependent degenerate Raman interaction
A theoretical scheme is presented for generating Gazeau-Klauder coherent
states(GKCSs) via the generalization of degenerate Raman interaction with
coupling constant to intensity-dependent coupling. Firstly, we prove that in
the intensity-dependent degenerate Raman interaction, under particular
conditions, the modified efective Hamiltonian can be used instead of
Hamiltonian in the interaction picture, for describing the atom-field
interaction. We suppose that the cavity field is initially prepared in a
nonlinear CS, which is not temporally stable. As we will observe, after the
occurrence of the interaction between atom and field, the generated state
involves a superposition of GKCSs which are temporally stable and initial
nonlinear CS. Under specific conditions which may be prepared, the generated
state just includes GKCS. So, in this way we produced the GKCS, successfully.Comment: 12 pages, 1 figures, Optics Communications, Article in Pres
The pattern of reproduction in the African giant pouched rat, Cricetomys gambianus, from Tanzania : unravelling the environmental triggers for breeding
DATA AVAILABILITY : The datasets presented in this article are not readily available because rights to this raw data are held by the institute and further permission is needed to release such data. Requests to access the datasets should be directed to DWH, [email protected] research represents the first extensive study of the breeding behaviour and related environmental triggers of reproduction in the African giant pouch rat (Cricetomys gambianus Waterhouse, 1840) in and around the equator throughout a whole year. We measured the gross morphology and detailed histology of both female and male rats, along with plasma steroid hormone levels. Contrary to other tropical-dwelling small mammals, the African giant pouch rat is a seasonal breeder; however, rainfall is not to be the primary cue of reproduction. Our study suggests that ambient temperature and photoperiod are the primary environmental cues of reproduction, with breeding occurring during the cooler months of the year, namely in the dry season. During the wet and hot season, which succeeds the dry season, there is an increase in the availability of quality food, which results in nursing mothers and weaned pups achieving a positive energy balance and increased body condition. This, in turn, increases pregnancy success and offspring survival. Climate change, particularly global warming, could harm the reproduction of African giant pouched rats as rising temperatures in and around the equator, including Tanzania, may impact their circannual reproductive cycle.The World Bank through African Centre of Excellence for Innovative Rodent Pest Management and Biosensor Technology Development at the Sokoine University of Agriculture (SUA), in Tanzania.https://cdnsciencepub.com/journal/cjzhj2024Mammal Research InstituteZoology and EntomologySDG-03:Good heatlh and well-beingSDG-15:Life on lan
States on pseudo effect algebras and integrals
We show that every state on an interval pseudo effect algebra satisfying
some kind of the Riesz Decomposition Properties (RDP) is an integral through a
regular Borel probability measure defined on the Borel -algebra of a
Choquet simplex . In particular, if satisfies the strongest type of
(RDP), the representing Borel probability measure can be uniquely chosen to
have its support in the set of the extreme points of $K.
The Lattice and Simplex Structure of States on Pseudo Effect Algebras
We study states, measures, and signed measures on pseudo effect algebras with
some kind of the Riesz Decomposition Property, (RDP). We show that the set of
all Jordan signed measures is always an Abelian Dedekind complete -group.
Therefore, the state space of the pseudo effect algebra with (RDP) is either
empty or a nonempty Choquet simplex or even a Bauer simplex. This will allow
represent states on pseudo effect algebras by standard integrals
Classical BI: Its Semantics and Proof Theory
We present Classical BI (CBI), a new addition to the family of bunched logics
which originates in O'Hearn and Pym's logic of bunched implications BI. CBI
differs from existing bunched logics in that its multiplicative connectives
behave classically rather than intuitionistically (including in particular a
multiplicative version of classical negation). At the semantic level,
CBI-formulas have the normal bunched logic reading as declarative statements
about resources, but its resource models necessarily feature more structure
than those for other bunched logics; principally, they satisfy the requirement
that every resource has a unique dual. At the proof-theoretic level, a very
natural formalism for CBI is provided by a display calculus \`a la Belnap,
which can be seen as a generalisation of the bunched sequent calculus for BI.
In this paper we formulate the aforementioned model theory and proof theory for
CBI, and prove some fundamental results about the logic, most notably
completeness of the proof theory with respect to the semantics.Comment: 42 pages, 8 figure
Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight
From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions
Interacting Kasner-type cosmologies
It is well known that Kasner-type cosmologies provide a useful framework for
analyzing the three-dimensional anisotropic expansion because of the
simplification of the anisotropic dynamics. In this paper relativistic
multi-fluid Kasner-type scenarios are studied. We first consider the general
case of a superposition of two ideal cosmic fluids, as well as the particular
cases of non-interacting and interacting ones, by introducing a
phenomenological coupling function . For two-fluid cosmological scenarios
there exist only cosmological scaling solutions, while for three-fluid
configurations there exist not only cosmological scaling ones, but also more
general solutions. In the case of triply interacting cosmic fluids we can have
energy transfer from two fluids to a third one, or energy transfer from one
cosmic fluid to the other two. It is shown that by requiring the positivity of
energy densities there always is a matter component which violates the dominant
energy condition in this kind of anisotropic cosmological scenarios.Comment: Accepted for publication in Astrophysics &Space Science, 8 page
De Sitter and Schwarzschild-De Sitter According to Schwarzschild and De Sitter
When de Sitter first introduced his celebrated spacetime, he claimed,
following Schwarzschild, that its spatial sections have the topology of the
real projective space RP^3 (that is, the topology of the group manifold SO(3))
rather than, as is almost universally assumed today, that of the sphere S^3.
(In modern language, Schwarzschild was disturbed by the non-local correlations
enforced by S^3 geometry.) Thus, what we today call "de Sitter space" would not
have been accepted as such by de Sitter. There is no real basis within
classical cosmology for preferring S^3 to RP^3, but the general feeling appears
to be that the distinction is in any case of little importance. We wish to
argue that, in the light of current concerns about the nature of de Sitter
space, this is a mistake. In particular, we argue that the difference between
"dS(S^3)" and "dS(RP^3)" may be very important in attacking the problem of
understanding horizon entropies. In the approach to de Sitter entropy via
Schwarzschild-de Sitter spacetime, we find that the apparently trivial
difference between RP^3 and S^3 actually leads to very different perspectives
on this major question of quantum cosmology.Comment: 26 pages, 8 figures, typos fixed, references added, equation numbers
finally fixed, JHEP versio
Holographic Dark Energy Model and Scalar-Tensor Theories
We study the holographic dark energy model in a generalized scalar tensor
theory. In a universe filled with cold dark matter and dark energy, the effect
of potential of the scalar field is investigated in the equation of state
parameter. We show that for a various types of potentials, the equation of
state parameter is negative and transition from deceleration to acceleration
expansion of the universe is possible.Comment: 11 pages, no figure. To appear in General Relativity and Gravitatio
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