The perching response and the laws of animal timing.

Homing pigeons were trained under differential-reinforcement-of-low-rate (DRL) or differential-reinforcement-of-response-duration (DRRD) schedules using a perching response. Schedule values ranged from 10 s to 70 s for DRL and from 12 s to 40 s for DRRD. In general, mean interresponse times or response durations were very close to the schedule requirement at all schedule values. A linear relation between mean response measure and schedule value described the data well, but power functions fared even better. The data also conformed well to the generalized Weber law; standard deviations of response measures varied as a linear function of the mean. Overall, the perching response produced data that conformed much more accurately to the schedule requirement—particularly at the longer schedule values—than did data from previous studies with both rats and pigeons. The results conformed well to the linear-type timing consistent with scalar timing theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How the new NIH guidelines on inclusion of women and minorities apply: Efficacy trials, effectiveness trials, and validity.

The NIH (National Institutes of Health) Guidelines on the Inclusion of Women and Minorities as Subjects in Clinical Research requires investigators applying for NIH research funds to develop and, if funded, implement plans for the inclusion of women and minority populations in their research, when that research involves human participants. It is the purpose of this article to help investigators understand (a) the scientific context and rationale behind the NIH Guidelines; (b) the NIH-defined concepts and the specific content of the NIH Guidelines; and (c) how the intent of the NIH Guidelines is related to mental health services research, the most applied area of mental health research. The article also discusses where investigators can find additional information as they work to implement the NIH Guidelines. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Therapeutic trials for promotion of faecal excretion of PCDFs by the administration of rice bran fiber and cholestyramine in Yusho patients

Two girls with Swyer syndrome (SS) were described. Diagnosis was established according to clinical data and ultrasound, laparoscope, histopathological, hormonal and cytogenetical examinations. One presents diagnostic possibilities followed advanced methods in genetics. The GTG and RBG high resolution bounding technique and replication analysis of short arms (Xp and Yp) were employed. Normal structure of end segments of X and Y chromosomes was mentioned. Molecular DNA analysis by polymerase chain reaction (PCR) did not find any mutation in SRY gene. Normal structure of this gene does not exclude possibility of SS existence. Our data implicates on the other mechanism of these disturbances.     

Relative biological effectiveness of negative pi mesons for the immune response in mice

Immunologically competent mouse spleen cells were exposed to negative pi mesons in the entrance plateau or at the peak of the dose distribution at a maximum dosage of 5 rads/min. or to 60Co gamma rays at 4.96 rads/min. Survival curves from cells irradiated in vitro but incubated in vivo yielded RBE values of 2.15 for the peak and 1.84 for the entrance plateau at a surviving fraction of 0.1. The dose-rate dependence of antibody-forming spleen cells for both 60Co gamma rays and the lot-LET components of the pion beam is discussed. The authors suggest that these RBE values constitute an upper limit for normal mammalian cells exposed to pions and tha the RBE with clinically useful dose rates may be significantly lower than those reported here.     

Value of results of animal experiments for the evaluation of drugs. 3. Animal trials and subjective probability

Inasmuch as the findings in pharmacology and toxicology are based on animal trials these disciplines have to be considered as subjective sciences, since the experimentally obtained objective data become medically relevant only on the basis of subjective probabilities. The value of pharmacological and toxicological tests is dependent on the quality of the investigator. Data obtained in animals trials are of no relevance for human medicine unless the investigator substantiates his subjective probabilities and at the same time demonstrates how the hypotheses won in animal trials can be verified in man. Toxicological testing methods allowing the "preselection" of drugs or any other kind of deductions without verification in man do not exist. Animal studies which are not based on the principles of decision theory serve merely as an alibi and may lead to wrong conclusions. Besides, they interfere with the German Animal Protection Law. Methodological problems can neither be solved by normative regulations of an administrative authority nor by increasing experimental activity.     

Countermeasures for radiocesium in animal products in Norway after the Chernobyl accident--techniques, effectiveness, and costs

Nine years after the reactor accident in Chernobyl contamination by radiocesium is still a significant problem in sheep and reindeer production in Norway. To reduce the impact of the accident, effective countermeasures had to be developed and implemented. The levels of radiocesium in meat were reduced by a combination of countermeasures such as special feeding, use of cesium binders (bentonite and Prussian blue), and changing of slaughtering time. The countermeasures were labor intensive and expensive. Costs per averted dose per person-Sv were calculated to range from NOK 1,000 to 100,000 (7 NOK = $1 U.S.), with the use of cesium binders being the least expensive and condemnation of meat the most costly. Dietary advice, which did not include any compensation costs, had a cost of NOK 40 per person-Sv. Apart from the rejection of meat in 1986, countermeasures were deemed to be justified on a cost-benefit basis (less than NOK 600,000 per person-Sv).     

Mechanisms of the cochlear nucleus octopus cell's onset response: synaptic effectiveness and threshold

Octopus cells are one of the principal cell types in the mammalian posteroventral cochlear nucleus. These cells respond to the onset of a toneburst with a precisely timed spike followed by little, if any, sustained activity. While experimental studies have partially characterized the cell, the mechanisms of this onset response are not well understood. The present study involved a model-based investigation that analyzed the responses of a compartmental model of the octopus cell in terms of synaptic effectiveness and dynamic spike threshold. The simulations demonstrate that properties of the onset response (first-spike latency, temporal precision of the first spike, and sustained firing rate) can be predicted from the values of these cell properties for a wide range of model configurations. These relationships were further analyzed through the development of mathematical expressions for synaptic effectiveness and dynamic spike threshold. This computational analysis resulted in a relatively simple explanation of the onset response, as well as predictions of the responses of octopus cells to nontonal, complex stimuli.     

Does knowledge of the response rule determine human performance on an animal test of amnesia?

Successful performance on delayed matching to sample (DMTS) is thought to require knowledge of the response rule and memory for the target stimuli. There is some uncertainty, however, over the relative importance of these 2 components in performance on DMTS. Therefore, alcohol-dependent individuals and normal controls were tested on a "lists" version of DMTS, where acquisition training and rule provision were manipulated in a factorial design. No acquisition effect was observed, but there was a modest effect of rule provision and a highly significant effect of list length. The results suggest that knowledge of the response rule does contribute to performance, but that memory for the stimuli over time is the major determinant of success on DMTS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measuring response empathy: The development of a multicomponent rating scale.

Describes psychometric data on a new approach to the measurement of the empathic quality of counselor behavior. The Response Empathy Rating Scale (1) divides the empathy construct into a set of components tapping different aspects of empathic behavior; (2) provides greater specification of the construct; and (3) focuses on the empathic qualities of individual counselor responses. Results from 28 counselor/client (undergraduates) pairs indicate good interrater reliability. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Wounds of the hand contaminated by human or animal saliva

A prospective and retrospective evaluation of 75 patients with hand wounds contaminated by human saliva (35) or animal saliva (40) demonstrates that a program of outpatient management can be sufficient for optimal care in many patients. This series challenges the proposition that hospitalization, radiographs, and surgical debridement are necessary for most such wounds. Sixty-seven per cent did not have surgical intervention and no complications resulted. Ninety-two per cent received antibiotics. Radiographs were obtained only when bony injury or entry into a joint was suspected. Delay in seeking treatment until obvious signs of infection or pain are present is common. Literature review details the anatomic factors important in the natural history and control of these infections, and the changes with respect to modes of treatment for these potentially dangerous wounds. The injury is caused by bites with the hand extended or, in fight-bite wounds, with the metacarpal-phalangeal and interphalangeal joints flexed, allowing deeper penetration and then sealing of the wound when the first is opened. Staphylococcus and Streptococcus are the organisms most frequently found in human bites, and in animal bites; Pasteurella multocida should be considered in dog and cat bites.     

Growth cone choices of Drosophila motoneurons in response to muscle fiber mismatch

In Drosophila embryos, each motoneuron is accurately matched to one or more singly identifiable muscle fibers. In this article we altered the number and pattern of the embryonic muscle fibers using genetic, heat shock, and laser ablation methods to test whether motoneuron growth cones are able to recognize specific targets. The choices made by two motoneurons were assayed using both intracellular dye fills and immunocytochemistry. The motoneurons RP1 and RP3 have nearly identical central and peripheral axonal trajectories. However, RP3 innervates the two most ventral longitudinal muscle fibers, 7 and 6, while RP1 grows past these fibers to innervate only muscle fiber 13. In rhomboid mutants muscle fiber 7 does not develop. Despite the loss of one of its targets, RP3 faithfully innervated the remaining muscle fiber 6 in over 80% of the observed cases. Furthermore, neuron RP1 accurately innervated muscle fiber 13, although it traversed one fiber fewer to reach it. Laser ablation of muscle fiber 7 confirmed the target choices shown by the motoneurons. In numb mutants, multiple muscle fibers, including 7, 13, and 12, fail to develop. This allowed us to test whether fibers distal to the target are involved in muscle fiber recognition, possibly by halting the growth cone advance. In mutant embryos, RP3 innervated muscle fiber 6 at the same frequency regardless of the absence of the distal muscle fiber 13. By contrast, RP1, which had lost its target entirely, frequently failed to innervate any muscle fiber during the period examined. Finally, muscle fiber 13 can be duplicated in wild-type embryos by means of a brief heat pulse during myogenesis. Presented with two targets, RP1 innervated both fibers in each case examined, while RP3 synapsed with muscle fibers 7 and 6 normally. Neuron-specific antibodies revealed that the embryonic growth cone choices were not transient, but persisted into the larval neuromuscular projections. These results indicate that each motoneuron growth cone has a primary target preference, which is retained even when the numbers of the muscle fibers, and therefore their relative positions, are altered. We therefore suggest that synaptic recognition by Drosophila motoneuron growth cones relies on unique features of the individual muscle fibers.     

电导法测量保护渣结晶温度

为了解决现行保护渣结晶温度测量手段存在着各种不足的问题,提出了电导法的研究思路.在理论分析了液渣电导激活能与析出相成分、结晶率之间的关系后,设计出了一种简易的测量方法,并采用差热分析(DTA)、偏光显微镜和X射线衍射法对其相关的测量结果进行了验证.结果表明:该测量方法准确度高,成本较低,对主要析出相的判断基本正确,可作为保护渣结晶温度的新型研究手段.     

Infiltration of fiber preforms by an

Preforms of 20 vol pct SAFFIL alumina fibers are infiltrated with Al-4.4 wt pct Cu-0.3 wt pct Mg using a horizontal die casting machine. Fiber preform temperature is varied from 973 to 673 K. Solute distribution, fiber volume fraction, and matrix microstructure are characterized using optical metallography and electron microprobe analysis. Increases in fiber volume fraction are observed in the composites downstream of the infiltration path. We propose that these result from locking of the compressed fibers by solid metal present during infiltration. With this as- sumption, we find good agreement between theory presented in Parts I [1] and II [2] for solute concentration, fiber volume fraction distributions, as well as matrix microstructure and exper- iments. With an initial preform temperature of 673 K, freckles are found in the composite, which are interpreted to result from the combined effects of pressure and significant enrichment in solute at the infiltration front.