14,659 research outputs found
The Relationship between Brachycephalic Head Features in Modern Persian Cats and Dysmorphologies of the Skull and Internal Hydrocephalus
Background: Cat breeders observed a frequent occurrence of internal hydrocephalus in Persian cats with extreme brachycephalic head morphology. Objective: To investigate a possible relationship among the grade of brachycephaly, ventricular dilatation, and skull dysmorphologies in Persian cats. Animals: 92 Persian-, 10 Domestic shorthair cats. Methods: The grade of brachycephaly was determined on skull models based on CT datasets. Cranial measurements were examined with regard to a possible correlation with relative ventricular volume, and cranial capacity. Persians with high (peke-face Persians) and lower grades of brachycephaly (doll-face Persians) were investigated for the presence of skull dysmorphologies.
Results: The mean cranial index of the peke-face Persians (0.97 ± 0.14) was significantly higher than the mean cranial index of doll-face Persians (0.66 ± 0.04; P < 0.001). Peke-face Persians had a lower relative nasal bone length (0.15 ± 0.04) compared to doll-face (0.29 ± 0.08; P < 0.001). The endocranial volume was significantly lower in doll-face than peke-face Persians (89.6 ± 1.27% versus 91.76 ± 2.07%; P < 0.001). The cranial index was significantly correlated with this variable (SpearmanŽs r: 0.7; P < 0.0001).
Mean ventricle: Brain ratio of the peke-face group (0.159 ± 0.14) was significantly higher compared to doll-face Persians (0.015 ± 0.01; P < 0.001). Conclusion and Clinical Relevance: High grades of brachycephaly are also associated with malformations of the calvarial and facial bones as well as dental malformations. As these dysmorphologies can affect animal welfare, the selection for extreme forms of brachycephaly in Persian cats should be reconsidered
Closure times of neurocranial sutures and synchondroses in Persian compared to Domestic Shorthair cats
Human-directed selective breeding has modified the phenotype of the modern Persian cat towards an extreme brachycephalic phenotype (âpeke-faceâ Persian), which originates from a spontaneous mutation that first appeared in the 1950s in traditional Persian types. It was suggested that the peke-face phenotype results from pathologic skull development and might represent a craniosynostosis of the coronal sutures. We followed this hypothesis and investigated the time dependent status of the neurocranial sutures and synchondroses in an ontogenetic series of doll-faced and peke-faced Persian cats compared to Domestic Shorthair cats (DSHs). Cranial suture closure was assessed by examining an ontogenetic series of formalin-fixed head specimens (nâ=â55) and dry skulls (nâ=â32) using micro-computed tomography. Sagittal, metopic, coronal and lambdoid sutures as well as intersphenoidal, spheno-occipital and spheno-ethmoid synchondroses were examined. Logistic regression analysis was performed to test the global effect of age on suture closure within a group of peke-face Persians, doll-face Persians and DSHs and the 50% probability of having a closed suture was calculated and compared between groups. Age was a perfect predictor for the condition of the coronal sutures in peke-face Persians. Coronal sutures were found to be closed at 0â0.3 months. In doll-face and DSHs, coronal sutures were open throughout the lifetime with the exception of a few very old cats. Results of this study confirmed a coronal craniosynostosis that likely causes the extreme brachycephalic skull morphology in the peke-face Persian
Fluctuation Analysis of the Atmospheric Energy Cycle
The atmosphere gains available potential energy by solar radiation and
dissipates kinetic energy mainly in the atmospheric boundary layer. We analyze
the fluctuations of the global mean energy cycle defined by Lorenz (1955) in a
simulation with a simplified hydrostatic model. The energy current densities
are well approximated by the generalized Gumbel distribution (Bramwell,
Holdsworth and Pinton, 1998) and the Generalized Extreme Value (GEV)
distribution. In an attempt to assess the fluctuation relation of Evans, Cohen,
and Morriss (1993) we define entropy production by the injected power and use
the GEV location parameter as a reference state. The fluctuation ratio reveals
a linear behavior in a finite range.Comment: 17 pages, 5 figure
Women fish vendors in Mumbai: a study report
Government development programmes and policies in fisheries are focused on the problems and needs of men though women are known to dominate the post-harvest sector in artisanal fisheries and are involved, to varying degrees, in pre-harvest and harvest activities. A lack of womenâs participation in decision-making bodies within communities, fisheries organizations and government has resulted in a general neglect of their interests. This has led to a constant demand by womenâs-rights activists and organizations to address market-related issues of women vendors.
This study, âWomen Fish Vendors in Mumbaiâ, aims to provide insights into the challenges faced by women fish vendors in the city of Mumbai (formerly Bombay)
Terminal Words
A terminal word is derived from, in order, the first and last letters of the first word and the first and last letters of the second word of a two word phrase
PEKE, Probabilistic Encryption Key Exchange, 10 Years Later, Including the PEKEv1.25 Specifications
This document revisits the PEKE (Probabilistic Encryption Key Exchange) cryptosystem and proposes the enhanced PEKEv1.25 that performs a hash computation on the original PEKE output in order to improve the security assurance and to broaden the field of use. For a key establishment application where only the server side publishes a long-term public key and can adequately protect the private key counterpart from implementation attacks, we claim that PEKE is unsurpassed in security and efficiency, among the finite field arithmetic cryptosystems (e.g. RSA and finite field Diffie-Hellman). We use an original definition for the type of key encapsulation service provided by PEKE, hoping that this abstract definition captures the characteristics of the protocol and usage context. However, we only suggest that related security proofs are encouraging for the security of PEKE
Strategic Asset Allocation, Asset Price Dynamics, and the Business Cycle
The main contribution of this work is to provide a dynamic general equilibrium model of asset allocation, allowing to reconcile economic theory with several puzzling contradictions recently pointed out in the literature: (i) the asset allocation puzzle, (ii) the observed time-variation in aggregate portfolio holdings, and (iii) the occurrence of twin peaks in equity and house prices. In this approach, compared to the existing literature, the main difference stems from the fact that, in addition to consumption and dividends, both prices and portfolio decisions are allowed to be endogenously determined within a general equilibrium framework. Secondly, real estate is introduced into the analysis, labor supply is allowed to be endogenously determined and macroeconomic shocks are the main source of riskiness.strategic asset allocation, real estate, house prices, business cycle, general equilibrium
Damping and scattering of electromagnetic waves by small ferrite spheres suspended in an insulator
The intentional degradation of electromagnetic waves by their penetration into a media comprised of somewhat sparsely distributed energy absorbing ferrite spheres suspended in an electrical insulator is investigated. Results are presented in terms of generalized parameters involving wave length and sphere size, sphere resistivity, permeability, and spacing; their influence on dissipation of wave power by eddy currents, magnetic hysteresis, and scattering is shown
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