2,996 research outputs found
Sexual dimorphisms in the dermal denticles of thelesser-spotted catshark, Scyliorhinus canicula (Linnaeus, 1758)
The dermal layers of several elasmobranch species have been shown to be sexually dimorphic. Generally, when this occurs the females have thicker dermal layers compared to those of males. This sexual dimorphism has been suggested to occur as a response to male biting during mating. Although male biting as a copulatory behaviour in Scyliorhinus canicula has been widely speculated to occur, only relatively recently has this behaviour been observed. Male S. canicula use their mouths to bite the female's pectoral and caudal fins as part of their pre-copulatory behaviour and to grasp females during copulation. Previous work has shown that female S. canicula have a thicker epidermis compared to that of males. The structure of the dermal denticles in females may also differ from that of males in order to protect against male biting or to provide a greater degree of friction in order to allow the male more purchase. This study reveals that the length, width and density of the dermal denticles of mature male and female S. canicula are sexually dimorphic across the integument in areas where males have been observed to bite and wrap themselves around females (pectoral fin, area posterior to the pectoral fin, caudal fin, and pelvic girdle). No significant differences in the dermal denticle dimensions were found in other body areas examined (head, dorsal skin and caudal peduncle). Sexually dimorphic dermal denticles in mature S. canicula could be a response to male biting/wrapping as part of the copulatory process
Posterior probability and fluctuation theorem in stochastic processes
A generalization of fluctuation theorems in stochastic processes is proposed.
The new theorem is written in terms of posterior probabilities, which are
introduced via the Bayes theorem. In usual fluctuation theorems, a forward path
and its time reversal play an important role, so that a microscopically
reversible condition is essential. In contrast, the microscopically reversible
condition is not necessary in the new theorem. It is shown that the new theorem
adequately recovers various theorems and relations previously known, such as
the Gallavotti-Cohen-type fluctuation theorem, the Jarzynski equality, and the
Hatano-Sasa relation, when adequate assumptions are employed.Comment: 4 page
Fluctuation Theorem in Rachet System
Fluctuation Theorem(FT) has been studied as far from equilibrium theorem,
which relates the symmetry of entropy production. To investigate the
application of this theorem, especially to biological physics, we consider the
FT for tilted rachet system. Under, natural assumption, FT for steady state is
derived.Comment: 6 pages, 2 figure
Transient fluctuation theorem in closed quantum systems
Our point of departure are the unitary dynamics of closed quantum systems as
generated from the Schr\"odinger equation. We focus on a class of quantum
models that typically exhibit roughly exponential relaxation of some observable
within this framework. Furthermore, we focus on pure state evolutions. An
entropy in accord with Jaynes principle is defined on the basis of the quantum
expectation value of the above observable. It is demonstrated that the
resulting deterministic entropy dynamics are in a sense in accord with a
transient fluctuation theorem. Moreover, we demonstrate that the dynamics of
the expectation value are describable in terms of an Ornstein-Uhlenbeck
process. These findings are demonstrated numerically and supported by
analytical considerations based on quantum typicality.Comment: 5 pages, 6 figure
Towards Defining, Assessing and Reporting Against National Standards for Literacy and Numeracy in New Zealand
The Education (National Standards) Amendment Act 2008 sets in place the
governmentâs ten-step Crusade for Literacy and Numeracy (Hon. John Key, 13
October, 2008). As part of that Crusade: (i) national standards will be set in literacy
and numeracy; (ii) every primary and intermediate student will be assessed regularly
against the national standards; and (iii) every primary and intermediate school will
report to parents in plain English about how their child is doing compared to national
standards and compared to other children their age. Where it is indicated, targeted
funding will be provided to enable schools to give assistance to the students who do
not meet national standards.
This paper discusses these elements of the Amendment Act, (referred to as ânational
standardsâ in this paper for simplicity), proposes a number of principles that should
underlie the design of an assessment, analysis and reporting system based on them;
and makes several suggestions for supporting their development and successful
implementation
Evaluation of be-38 percent al alloy final report, 27 jun. 1964 - 28 feb. 1965
Mechanical properties, microstructural features, and general metallurgical quality of beryllium- aluminum allo
A feasibility, randomised controlled trial of a complex breathlessness intervention in idiopathic pulmonary fibrosis (BREEZE-IPF): study protocol
Introduction Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive lung disease that causes breathlessness and cough that worsen over time, limiting daily activities and negatively impacting quality of life. Although treatments are now available that slow the rate of lung function decline, trials of these treatments have failed to show improvement in symptoms or quality of life. There is an immediate unmet need for evidenced-based interventions that improve patients' symptom burden and make a difference to everyday living. This study aims to assess the feasibility of conducting a definitive randomised controlled trial of a holistic, complex breathlessness intervention in people with IPF.
Methods and analysis The trial is a two-centre, randomised controlled feasibility trial of a complex breathlessness intervention compared with usual care in patients with IPF. 50 participants will be recruited from secondary care IPF clinics and randomised 1:1 to either start the intervention within 1â
week of randomisation (fast-track group) or to receive usual care for 8â
weeks before receiving the intervention (wait-list group). Participants will remain in the study for a total of 16â
weeks. Outcome measures will be feasibility outcomes, including recruitment, retention, acceptability and fidelity of the intervention. Clinical outcomes will be measured to inform outcome selection and sample size calculation for a definitive trial.
Ethics and dissemination Yorkshire and The Humber â Bradford Leeds Research Ethics Committee approved the study protocol (REC 18/YH/0147). Results of the main trial and all secondary end-points will be submitted for publication in a peer-reviewed journal
A quantum version of free energy - irreversible work relations
We give a quantum version of the Jarzynski relation between the distribution
of work done over a certain time-interval on a system and the difference of
equilibrium free energies. The main new ingredient is the identification of
work depending on the quantum history of the system and the proper definition
of various quantum ensembles over which the averages should be made. We also
discuss a number of different regimes that have been considered by other
authors and which are unified in the present set-up. In all cases, and quantum
or classical, it is a general relation between heat and time-reversal that
makes the Jarzynski relation so universally valid
Thermodynamic metrics and optimal paths
A fundamental problem in modern thermodynamics is how a molecular-scale
machine performs useful work, while operating away from thermal equilibrium
without excessive dissipation. To this end, we derive a friction tensor that
induces a Riemannian manifold on the space of thermodynamic states. Within the
linear-response regime, this metric structure controls the dissipation of
finite-time transformations, and bestows optimal protocols with many useful
properties. We discuss the connection to the existing thermodynamic length
formalism, and demonstrate the utility of this metric by solving for optimal
control parameter protocols in a simple nonequilibrium model.Comment: 5 page
Steady State Thermodynamics of Langevin Systems
We study Langevin dynamics describing nonequilibirum steady states. Employing
the phenomenological framework of steady state thermodynamics constructed by
Oono and Paniconi [Prog. Theor. Phys. Suppl. {\bf130}, 29 (1998)], we find that
the extended form of the second law which they proposed holds for transitions
between steady states and that the Shannon entropy difference is related to the
excess heat produced in an infinitely slow operation. A generalized version of
the Jarzynski work relation plays an important role in our theory.Comment: 4 page
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