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1.
This study aimed to describe and compare the role of veterinarians and feed-store vendors in the use of antibiotics on small dairy farms in Cajamarca, Peru, a major dairy-producing center characterized by small, rural farms with poor, mostly uneducated farmers. We used a purposive sampling strategy to recruit 12 veterinarians into 2 focus group discussions and supplemented these data with 8 semi-structured interviews with feed-store vendors. Participants reported that inappropriate antibiotic usage was widespread among their clients, which may prevent the efficient use of drugs on farms where animal disease can be devastating to the livelihood of the farmer. Participants also identified many barriers to appropriate prescribing and use, including availability of drugs, competition from other prescribers, economic constraints and habits of farmers, and limited farmer knowledge of drugs and disease. Veterinarians expressed mistrust toward nonprofessional prescribers, whereas feed-store vendors felt that veterinarians were important partners in promoting the health of their clients’ animals.  相似文献   
2.
An analogy is examined between serially concatenated codes and parallel concatenations whose interleavers are described by bipartite graphs with good expanding properties. In particular, a modified expander code construction is shown to behave very much like Forney's classical concatenated codes, though with improved decoding complexity. It is proved that these new codes achieve the Zyablov bound /spl delta//sub Z/ on the minimum distance. For these codes, a soft-decision, reliability-based, linear-time decoding algorithm is introduced, that corrects any fraction of errors up to almost /spl delta//sub Z//2. For the binary-symmetric channel, this algorithm's error exponent attains the Forney bound previously known only for classical (serial) concatenations.  相似文献   
3.
We address the maximum attainable rate of fingerprinting codes under the marking assumption, studying lower and upper bounds on the value of the rate for various sizes of the attacker coalition. Lower bounds are obtained by considering typical coalitions, which represents a new idea in the area of fingerprinting and enables us to improve the previously known lower bounds for coalitions of size two and three. For upper bounds, the fingerprinting problem is modeled as a communications problem. It is shown that the maximum code rate is bounded above by the capacity of a certain class of channels, which are similar to the multiple-access channel (MAC). Converse coding theorems proved in the paper provide new upper bounds on fingerprinting capacity. It is proved that capacity for fingerprinting against coalitions of size two and three over the binary alphabet satisfies and , respectively. For coalitions of an arbitrary fixed size , we derive an upper bound on fingerprinting capacity in the binary case. Finally, for general alphabets, we establish upper bounds on the fingerprinting capacity involving only single-letter mutual information quantities.  相似文献   
4.
Open porous mechanically stable ceramic foams are developed by a simple direct foaming process. The new processing route is based on the transition of a surfactant stabilized highly concentrated alkane phase homogeneously distributed in a stabilized aqueous ceramic powder suspension into high performance ceramic foams with porosities up to 90% and cell sizes ranging from 3 to 200 μm. The droplet size distribution of the high alkane phase emulsified suspensions (HAPES) is efficiently controlled by the stirring velocity during emulsification experimentally investigated for varying powder particle contents. Stable foams with tailored structural features can be prepared by adjusting the rheological characteristics of HAPES being dependent on the system and process parameters. The influence of the emulsification stirring velocity on the resulting HAPES droplet size is analysed on the basis of the Taylor model of mechanical shearing describing the stresses responsible for the fragmentation of the droplets.  相似文献   
5.
Studies have suggested that individuals with physical disabilities are often stigmatized and are perceived to possess less favorable physical and psychological characteristics than individuals without disability. Purpose: To investigate whether able-bodied adults' perceptions of people with different causes of spinal cord injury (SCI) are influenced by physical activity status information. Method and Participants: Each participant (N = 198) read all five vignettes describing individuals with SCI who had varying levels of physical activity participation and cause of injury information (e.g., onset-uncontrollable [hit by impaired driver] and onset-controllable [caused by impaired driving]). After reading each vignette, participants completed a 12-item Warmth and Competence Questionnaire to evaluate each target. One-way repeated measures multivariate analyses of variance were conducted to examine the within-subjects differences. Results: Physically active individuals with onset-uncontrollable SCI were rated most favorably on warmth and competence. Physically active individuals with onset-controllable SCI also were rated more favorably on warmth and competence than physically inactive targets with onset-controllable SCI. Conclusion: A physically active lifestyle may be beneficial in managing the stigma experienced by individuals with both onset-controllable and onset-uncontrollable SCI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
6.
Two deterministic algorithms of computing the weight spectra of binary cyclic codes are presented. These algorithms have the lowest known complexity for cyclic codes. For BCH codes of lengths 63 and 127, several first coefficients of the weight spectrum in number sufficient to evaluate the bounded distance decoding error probability are computed  相似文献   
7.
 A relation between the Hamming weight enumerator of a linear code and the Tutte polynomial of the corresponding matroid has been known since long ago. It provides a simple proof of the MacWilliams equation (see D. Welsh, Matroid Theory (1976)). In this paper we prove analogous results for the support weight distributions of a code. Received March 5, 1996; revised version October 28, 1996  相似文献   
8.
We consider a general fingerprinting problem of digital data under which coalitions of users can alter or erase some bits in their copies in order to create an illegal copy. Each user is assigned a fingerprint which is a word in a fingerprinting code of size M (the total number of users) and length n. We present binary fingerprinting codes secure against size-t coalitions which enable the distributor (decoder) to recover at least one of the users from the coalition with probability of error exp(-/spl Omega/(n)) for M=exp(/spl Omega/(n)). This is an improvement over the best known schemes that provide the error probability no better than exp(-/spl Omega/(n/sup 1/2/)) and for this probability support at most exp(O(n/sup 1/2/)) users. The construction complexity of codes is polynomial in n. We also present versions of these constructions that afford identification algorithms of complexity poly(n)=polylog(M), improving over the best previously known complexity of /spl Omega/(M). For the case t=2, we construct codes of exponential size with even stronger performance, namely, for which the distributor can either recover both users from the coalition with probability 1-exp(/spl Omega/(n)), or identify one traitor with probability 1.  相似文献   
9.
To investigate the effect of hyperinsulinemia on arteriolar hypertrophy, myocardial hypertrophy, and blood pressure, we administered insulin intraperitoneally to SHR and WKY rats for 3 consecutive weeks. To prevent hypoglycemia, the drinking water contained 10% sugar, and to accentuate the blood pressure, their chow contained 8% table salt. Blood pressure was measured by the tail-cuff method. Heart weights were factored with body weights. Arterioles of approximately 100 microns in diameter were examined at the end of the experiment and the vascular wall thickness was factored with the lumen diameter. At the end of 3 weeks, blood pressure rose in the SHR but not in the WKY rats. The heart weights in the WKY normotensive rats did not increase, whereas in the SHR they did. Furthermore, there was a significant rise in vessel wall thickness in the rats that received insulin, whether there was a rise in blood pressure or not and whether they had an increase in heart weight or not. There was a similar rise in blood glucose in all the groups, with slightly more accentuated rise in the SHR that received insulin. Nevertheless the increase in vascular wall thickness occurred only in the groups which received insulin. This seems to preclude the importance of hyperglycemia per se as the causative agent for the increase in vascular wall thickness in this study. The increase was in the form of medial hypertrophy without any sign of atherosclerosis. It seems, therefore, that hyperinsulinemia is associated with hypertrophy of the media of arterioles regardless of the increase in heart weight or the rise in blood pressure.  相似文献   
10.
In the present work, the process of biodiesel production in a pilot plant has been studied using beef tallow as raw materials with methanol and potassium hydroxide as catalyst. The biodiesel quality is regulated by Brazilian specifications (Resolution 42) by the National Agency of Petroleum (ANP). The alkaline transesterification of animal fat with methanol produces a biodiesel with high quality and also with a good conversion rate. The process is possible but the economical viability must be improved by recovering methanol and glycerin. The obtained results have been used for industrial scale up of the process.  相似文献   
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