955 research outputs found
A Study of Sex Differences in Various Statistics Calculated from Data on Growing Angus Bulls and Heifers Fed at Different Levels.
The objective of this study was to assess the relative importance of sire differences, sex differences and sire by sex interaction influence on variation among individuals in various recorded variables and to estimate the heritability of these variables. Data were obtained from 858 Angus calves sired by 85 sires over a period of 6 years (1968-1973) from the purebred Angus herd at the Plateau Experiment Station of The University of Tennessee. The traits recorded on each animal at weaning (at an average age of 231 days) and after post-weaning feeding (at an average age of 385 days) were Body Weight, Type Score, Condition Score, Average Daily Gain, Heart Girth, Body Length and Hip Width. Lifetime (to a year of age) average daily gain also was calculated. Restricted feeding of heifer calves and full feeding of bull calves were followed during the post-weaning period. Heifers were restricted to prevent the excessive fattening which can occur on a high plane of feeding from jeopardizing their future reproductive and milking abilities. Nested within-year analyses were performed on these data. Least-square estimates of the effects of sex, sire (within year) and sire-sex (within year) interaction on the various traits were obtained. Results showed highly significant sire effects on all the traits studied. Sex effects also were highly significant (P \u3c .01) with respect to all traits but two. Type Score measured at both stages and Hip Width at weaning. Sire by sex interaction effects were non-significant in all traits except for Type and Condition Scores measured at weaning and Average Daily Gain at post-weaning. These interactions, however, were probably due to sampling because of a small number of sires or a small number of progeny per sire. Bartlett\u27s test of homogeneity of variance was conducted in order to justify statistically the pooling of the data over the six-year period. Results of the test indicate homogeneity of variances of all traits except one, Condition Score at post-weaning. Level of significance of differences in variances between sexes was tested by a simple F-test, using variance components of pooled data for each sex. This test showed highly significant (P \u3c .01) sex dif-ferences with respect to variances due to differences between offspring of the same sire (s2W). However, some of the sex differences in variances due to sire differences (s2S) were not significantly (P \u3e .05) different. All of the sex differences in total variance (s2) were highly significant (P \u3c .01). Heritability estimates were calculated for each sex separately, at weaning and at a year of age, using the method of half-sib correla-tions. The results indicate higher heritability estimates in heifers than in bulls which suggests that heifer progeny provide more effective genetic discrimination between sires than would bull progeny at early ages of the calves and that selection among females may be more nearly as effective as that among males than is usually believed, the higher heritability in females offsetting, to some extent, the lower intensity of selection among females as compared to that among males. In general, data from heifers yielded higher herit-ability estimates, especially at weaning. These differences, however, were smaller at post-weaning and even reversed in the case of body dimension traits for which post-weaning data from bulls yielded higher estimates of heritability than did post-weaning data from heifers
Dabkeh al Djoufieh: Exploring the Sustainability of Jordanian Folklore
The authors of this paper analyze the Dabkeh al Djoufieh (Dabkɛ ālǧwofyɛ) in its capacity as an inherent part of Jordanian folklore that has been seldom studied. Whereas contemporary Jordan has experienced a rapid burst of cultural globalization, the rural song and dance of Dabkeh al Djoufieh can be observed as a highly dynamic manifestation of belonging and as a symbol of national solidarity. One of the defining features of the Dabkeh al Djoufieh is that it is immanent in every social event in Arab communities. Secondly, as a sample of folk music, Dabkeh al Djoufieh continues to be a vibrant resource for contemporary audiences. The paper focuses on the main musical and poetic characteristics of Dabkeh al Djoufieh. The qualitative analysis applied integrates ideas concerning semantics as a representation of the social context and ethnic identities, whereas music is viewed as an indicator of local heritage. This paper probes the questions: What is Dabkeh Djoufieh? Where does it originate? And how is it implemented in Jordanian folklore culture?
Furthermore, the study discusses the social power found within poetic folk verse, specifically, the role of the metaphor as a tool for expressing communal realities and individual experiences. Likewise, the study analyzes the musical features of the traditional Dabkeh al Djoufieh and how it moved across generations, sacred and social boundaries, becoming a symbol of Jordanian folk tradition.Gli autori di questo articolo analizzano il Dabkeh al Djoufieh (Dabkɛ ālǧwofyɛ) come parte intrinseca del folclore giordano studiato raramente. Mentre la Giordania contemporanea ha vissuto una rapida esplosione di globalizzazione culturale, il canto e la danza rurali di Dabkeh al Djoufieh possono essere osservati come una manifestazione altamente dinamica di appartenenza e come un simbolo di solidarietà nazionale. Una delle caratteristiche distintive del Dabkeh al Djoufieh è che è presente in ogni evento sociale nelle comunità arabe. In secondo luogo, come esempio di musica folk, Dabkeh al Djoufieh continua a essere una vivace risorsa per il pubblico contemporaneo. L'articolo si concentra sulle principali caratteristiche musicali e poetiche di Dabkeh al Djoufieh. L'analisi qualitativa applicata integra idee riguardanti la semantica come rappresentazione del contesto sociale e delle identità etniche, mentre la musica è vista come un indicatore del patrimonio locale. Questo articolo pone le domande: Cos'è Dabkeh Djoufieh? Da dove proviene? E come viene implementato nella cultura folcloristica giordana?
Inoltre, lo studio discute il potere sociale che si trova nei versi popolari poetici, in particolare, il ruolo della metafora come strumento per esprimere realtà comuni ed esperienze individuali. Allo stesso modo, lo studio analizza le caratteristiche musicali del tradizionale Dabkeh al Djoufieh e come si è tramandato attraverso generazioni, confini sacri e sociali, diventando un simbolo della tradizione popolare giordana
Generalization of Retractable and Coretractable Modules
In this work, we extend the notion of retractability to s- retractability. An R-module is called s-retractable if for all nonzero . Also we extend coretractable modules to semi-coretractable modules. An R-module is called semi-coretractable if for all maximal essential submodule of . We investigate theseclasses of modules and extend some of main theorems on retractable and coretractable modules to s-retractable and semi-coretractable modules, respectively
The perimeter of uniform and geometric words: a probabilistic analysis
Let a word be a sequence of i.i.d. integer random variables. The
perimeter of the word is the number of edges of the word, seen as a
polyomino. In this paper, we present a probabilistic approach to the
computation of the moments of . This is applied to uniform and geometric
random variables. We also show that, asymptotically, the distribution of is
Gaussian and, seen as a stochastic process, the perimeter converges in
distribution to a Brownian motionComment: 13 pages, 7 figure
Learning Cyber Defence Tactics from Scratch with Multi-Agent Reinforcement Learning
Recent advancements in deep learning techniques have opened new possibilities
for designing solutions for autonomous cyber defence. Teams of intelligent
agents in computer network defence roles may reveal promising avenues to
safeguard cyber and kinetic assets. In a simulated game environment, agents are
evaluated on their ability to jointly mitigate attacker activity in host-based
defence scenarios. Defender systems are evaluated against heuristic attackers
with the goals of compromising network confidentiality, integrity, and
availability. Value-based Independent Learning and Centralized Training
Decentralized Execution (CTDE) cooperative Multi-Agent Reinforcement Learning
(MARL) methods are compared revealing that both approaches outperform a simple
multi-agent heuristic defender. This work demonstrates the ability of
cooperative MARL to learn effective cyber defence tactics against varied
threats.Comment: Presented at 2nd International Workshop on Adaptive Cyber Defense,
2023 (arXiv:2308.09520
- …