Effects of feed withdrawal before delivery on pork quality and carcass yield

A total of 270 pigs from a Yorkshire/Duroc/Landrace 3-way cross, reared under an ad libitum feed regimen, were delivered for slaughter after fasting (with access to water) for 24 and 0 h (Exp. 1), 16 and 0 h (Exp. 2) and 24, 16 and 0 h (Exp. 3). The interval between delivery and slaughter was 4-5 h. Feeding until delivery resulted in a lower pH at 45 min post mortem in the longissimus muscle. Ultimate pH values of longissimus and semimembranosus muscles were higher after feed restriction for 24 h. However, the incidence of dark, firm and dry (DFD) (pH > 6·2) was also increased after fasting in Exp. 1. Assessment of meat quality in samples taken from the longissimus at 20 h post mortem showed that, in comparison with feeding until delivery. Hunter L(?) (Lightness)-values and drip loss decreased and firmness improved by prolonged fasting (24 h). Fasting for 16 h did not reduce drip loss, but colour was improved (lower Hunter L(?)-values) in Exp. 3, although not in Exp. 2. Feeding until delivery resulted in better meat quality in Exp. 2 than in Exp. 1 and 3. A significant reduction in dressing percentage as a result of fasting was only found in Exp. 1. There appears no economic disadvantage in restricting feed for 16 h prior to delivery. Although the incidence of DFD may also increase, a fasting period of 16-24 h is recommended to reduce pale, soft and exudative (PSE) muscle, while losses in carcass yield are minimized. Other advantages of fasting are discussed.     

Invariant object recognition and pose estimation with slow feature analysis

Primates are very good at recognizing objects independent of viewing angle or retinal position, and they outperform existing computer vision systems by far. But invariant object recognition is only one prerequisite for successful interaction with the environment. An animal also needs to assess an object's position and relative rotational angle. We propose here a model that is able to extract object identity, position, and rotation angles. We demonstrate the model behavior on complex three-dimensional objects under translation and rotation in depth on a homogeneous background. A similar model has previously been shown to extract hippocampal spatial codes from quasi-natural videos. The framework for mathematical analysis of this earlier application carries over to the scenario of invariant object recognition. Thus, the simulation results can be explained analytically even for the complex high-dimensional data we employed.     

Methods of predicting pale, soft, exudative pork and their application in breeding programmes-A review

The condition of pale, soft, exudative (PSE) pork has long been considered to be mainly a post mortem phenomenon. There is now substantial evidence that such pigs are suffering from a kind of myopathy, which predisposes them to an abnormal post mortem metabolism. Genetic studies on PSE muscle indicate a moderate heritability for various post mortem muscle quality traits. Reliable methods for determining the abnormal condition in the live animal would make it possible to select more effectively and economically against stress and PSE-susceptibility. Three possible methods are: (1) Analysis of blood serum for CPK, aldolase, GOT or other enzyme activities with and without preceding exercise; and for blood groups. (2) Muscle biopsy analysis for glucose-6-phosphate, lactate or energy-rich phosphates. (3) Non-destructive testing of young pigs for sensitivity to the Malignant Hyperthermia Syndrome by allowing them to inhale the anaesthetic halothane (fluothane) for a 5 min period. The development of muscular rigidity and stiffness indicates a susceptibility to stress and a potential for PSE meat. The relationships of the various methods to ultimate muscle and carcass quality, as well as the problems inherent to each method, are discussed. It is concluded that the third test seems to be the most promising for application in the breeding of pigs for optimal stress resistance and muscle quality.     

Scheduling and lot sizing with sequence-dependent setup: A literature review

This paper reviews the literature related to the class of scheduling problems that involve sequence-dependent setup times (costs), an important consideration in many practical applications. It focuses on papers published within the last decade, addressing a variety of machine configurations including single machine, parallel machine, flow shop, and job shop systems and reviews the optimization and heuristic solution methods used for each category. Since lot sizing is so intimately related to scheduling, this paper reviews work that integrates these issues in relationship to each configuration. This paper provides a perspective of this line of research, gives conclusions, and discusses fertile research opportunities posed by this class of scheduling problems.     

Record-keeping practices of clinical and counseling psychologists: A survey of practitioners.

Record keeping by psychologists was examined with survey data. Results indicate substantial variability in policies and practices. Implications of the results are discussed, and it is recommended that more specific guidelines for practitioners be developed in order to reduce the variability in record keeping. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Proceedings of the American Psychological Association, Incorporated, for the year 1971: Minutes of the Annual Meeting of the Council of Representatives.

Presents the minutes of the Annual Meeting of the Council of Representatives of the American Psychological Association for the year 1971. These minutes constitute the official record of actions of the Association taken during the year. Reference is made to various reports, some of which will be published elsewhere. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Computational comparison of two formulations for dynamic supply chain reconfiguration with capacity expansion and contraction

The strategic dynamic supply chain reconfiguration (DSCR) problem is to prescribe the location and capacity of each facility, select links used for transportation, and plan material flows through the supply chain, including production, inventory, backorder, and outsourcing levels. The objective is to minimize total cost. The network must be dynamically reconfigured (i.e., by opening facilities, expanding and/or contracting their capacities, and closing facilities) over time to accommodate changing trends in demand and/or costs. The problem involves a multi-period, multi-product, multi-echelon supply chain. Research objectives of this paper are a traditional formulation and a network-based model of the DSCR problem; tests to promote intuitive interpretation of our models; tests to identify computational characteristics of each model to determine if one offers superior solvability; and tests to identify sensitivity of run time relative to primary parameters.     

Research on college teaching: The historical background.

Experimental research on college teaching began with single variable studies of class size and lecture vs discussion. During the 1930s, research on student ratings of teachers began, and following World War II, studies of college teaching and learning became more common. In the decades from then to the 1980s, research moved to concern with a broader range of variables, to analyses of interactions between student and classroom variables, and to attention to processes as well as products resulting from teaching. Research on college teaching clearly meets J. B. Conant's (1947) criteria for a scientific field: progress in theory, methods, and established knowledge. Moreover, we now have demonstrated that educational research can contribute to educational practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)