木质鸡胸肉生肉品质表征及检测方法研究

目的探索木质肉(woody/wooden breast,WB)生肉品质特性差异及客观检测方法。方法对不同木质鸡胸肉等级样本的重量、挤压力(CF Probe、CF TA-25)进行检测,同时在剪切实验中以剪切力(MORSF)、剪切做功(MORSE)及剪切峰值个数(PC-MORS)作为生肉质构分析指标。结果重量、CF Probe、CF TA-25、MORSF、MORSE、PC-MORS随着WB等级的递增而显著增大,2种硬度检测探头均可用于鸡胸肉的硬度检测。PC-MORS在MORSF和MORSE的基础上可有效区分WB等级,同时可显示鸡胸肉肌肉内部的层状结构信息。各测量指标之间存在不同程度的相关性,其中重量、CF Probe、MORSE、PC-MORS与WB等级之间存在极显著相关。建立的BP神经网络模型区分正常肉和木质肉的总体识别率达90.6%。结论本研究确定了木质鸡胸肉生肉硬度检测方法、质构分析的特征参数,并研究其木质化等级判定模型,研究结果可为后续木质鸡胸肉在线检测分级装置的研发提供一定的理论支撑。     

Effects of hostility on ambulatory blood pressure and mood during daily living in healthy adults.

This study (a) tested the effects of hostile attributes on ambulatory blood pressure (BP), heart rate, and mood monitored repeatedly over 3 days in 100 healthy men and women and (b) determined whether the cardiovascular effects of trait hostility were moderated by mood. Multilevel random-coefficients regression analyses showed that hostile individuals exhibited higher systolic and diastolic BP and rated their current moods as more negative and less positive throughout the monitoring. Individuals low in hostility exhibited high BP only during the few occasions when they experienced negative mood. However, these patterns were true only when participants were classified by Potential for Hostility ratings from the Structured Interview (R. H. Rosenman, 1978), not by the Cynical Hostile Attitudes score derived from the Cook-Medley scale. Results provide convergent and ecological validity of interview rating of hostility and illuminate one possible dynamic mechanism by which overt hostile behaviors might contribute to the rates of increased cardiovascular morbidity and mortality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

超前思维与社会教育

本文论述了教育心理学中超前思维与社会教育相互关系的几个重要问题。首先 ,超前思维是一种特殊的心理活动 ,这种心理活动的特征突出地表现为人类思维对于时间、空间和具体事物的超越性。其次 ,超前思维的形成会受到社会教育的制约 ,主要是家庭教育、学校教育和职业教育的制约。第三 ,超前思维对社会教育的发展具有重要的促进作用 ,这种作用对社会教育目标的选择具有三个方面的效应     

Correction of empty-field myopia on the basis of the dark-focus of accommodation.

The influence of negative spherical corrections on the detection of a small increment flash presented in a uniform field or Ganzfeld were determined. The range investigated included each observer's normal correction as well as values based on the focus assumed by each observer in total darkness (dark-focus of accomodation). A correction equivalent to the dark-focus resulted in maximum sensitivity. The results suggest a convenient technique for the determination of optimal correction for empty-field viewing conditions.     

Light aversion in mice depends on nonimage-forming irradiance detection.

Detection of light in the eye underlies image-forming vision, but also regulates adaptive responses in physiology and behavior. Typically these adaptive responses do not involve image-forming vision, but depend on a relatively absolute measure of brightness (nonimage-forming irradiance detection). The goal of this study was to further understand how image-forming vision and nonimage-forming irradiance detection contribute to the effects of light on behavior. Three light dependent behaviors were assessed in wild-type, Rpe65-/- and rd1 mice. In Rpe65-/- mice, nonimage-forming irradiance detection is severely attenuated, but rod based visual acuity is relatively preserved. In rd1 mice visual acuity is nonrecordable, but nonimage-forming responses are less severely attenuated than Rpe65-/-. Positive masking, an image-forming vision dependent increase in wheel running, was absent in rd1 and restricted to higher irradiances in Rpe65-/-. Negative masking, a suppression of wheel running sensitivity with nonimage-forming irradiance detection input, was increased in rd1, but reduced in Rpe65-/- mice. By contrast, light aversion, an avoidance of brightly lit areas, was abolished in both Rpe65-/- and rd1. This shows that image-forming vision is not sufficient for light aversion, suggesting nonimage-forming irradiance detection motivates this behavior. Further, the differing effects of disease suggest that negative masking and light aversion are distinct responses with specialized nonimage-forming irradiance detection pathways. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the Repeatability and Quality of Keypoints for Local Feature-based 3D Object Retrieval from Cluttered Scenes

3D object recognition from local features is robust to occlusions and clutter. However, local features must be extracted from a small set of feature rich keypoints to avoid computational complexity and ambiguous features. We present an algorithm for the detection of such keypoints on 3D models and partial views of objects. The keypoints are highly repeatable between partial views of an object and its complete 3D model. We also propose a quality measure to rank the keypoints and select the best ones for extracting local features. Keypoints are identified at locations where a unique local 3D coordinate basis can be derived from the underlying surface in order to extract invariant features. We also propose an automatic scale selection technique for extracting multi-scale and scale invariant features to match objects at different unknown scales. Features are projected to a PCA subspace and matched to find correspondences between a database and query object. Each pair of matching features gives a transformation that aligns the query and database object. These transformations are clustered and the biggest cluster is used to identify the query object. Experiments on a public database revealed that the proposed quality measure relates correctly to the repeatability of keypoints and the multi-scale features have a recognition rate of over 95% for up to 80% occluded objects.     

Deoxyribonucleic acid fingerprinting of Staphylococcus aureus from heifer mammary secretions and from horn flies.

Staphylococcus aureus isolated from heifer mammary secretions, streak canals, and horn flies (Haematobia irritans) were evaluated by randomly amplified polymorphic DNA fingerprinting. The relationship between DNA fingerprint patterns of S. aureus isolated from horn flies and S. aureus isolated from heifer mammary glands was examined. Amplified DNA fragments were visualized by agarose gel electrophoresis and were analyzed by densitometry. Analysis of DNA fingerprint patterns of 56 S. aureus isolates that were obtained from heifer mammary secretions or streak canals resulted in three distinct subtypes of S. aureus. Of these, 31 isolates (55%) belonged to subtype 1, 22 isolates (39%) belonged to subtype 2, and 3 (5%) belonged to subtype 3. Eight of 10 S. aureus isolates from horn flies belonged to subtype 1, and 2 isolates belonged to subtype 2. Thus, all of the S. aureus isolates from horn flies had DNA fingerprint patterns identical to the majority (95%) of S. aureus isolates from heifer mammary secretions or streak canals. In addition, 10 S. aureus isolates from multiparous cows from the same herd were examined by randomly amplified polymorphic DNA. All S. aureus isolates from multiparous cows belonged to subtype 3. Results of this study suggest that horn flies may play an important role in the transmission of S. aureus to nulligravid and primigravid heifers. Furthermore, this study demonstrates the usefulness of randomly amplified polymorphic DNA fingerprinting to distinguish between different subtypes of S. aureus and to draw epidemiological inferences from the information it provides.     

Propagation results at 11 GHz for microcellular radio

Given the limited spectrum allocated to cellular mobile radio, the authors consider the use of microwave frequency bands where larger bandwidth allocations may be feasible. A radio network of 'microcells' has been proposed for such bands. They have conducted a propagation experiment at 11 GHz to characterise such communication channels in various environments. Results are given for rural and semi-urban environments, where propagation is found to be dominated by interference between the direct ray and a roadway-reflected ray.<>     

Treatment of Staphylococcus aureus mastitis with penicillin and novobiocin: antibiotic concentrations and bacteriologic status in milk and mammary tissue

Cows with Staphylococcus aureus mastitis received either one or two intramammary infusions containing 100,000 U penicillin G and 150 mg novobiocin. Milk and tissue samples were obtained from each quarter. Peak mean penicillin and novobiocin concentrations from antibiotic-positive tissue samples were .013 U/mg and .06 microgram/mg, respectively, for quarters treated once. Quarters treated twice had peak mean penicillin and novobiocin concentrations of .057 U/mg and .06 microgram/mg, respectively. Viable Staphylococcus aureus were isolated intermittently from milk and tissue samples of quarters positive for penicillin and novobiocin for both treatment groups. Histological analysis of mammary parenchyma demonstrated marked decreases in luminal area and increases in connective tissue area and leukocyte infiltration in S. aureus-infected quarters compared with uninfected controls, suggesting that reduction in milk collecting space and presence of inflammatory changes may be responsible for poor drug distribution.