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31.
P Brown L Cervenáková L McShane LG Goldfarb K Bishop F Bastian J Kirkpatrick P Piccardo B Ghetti DC Gajdusek 《Canadian Metallurgical Quarterly》1998,50(3):684-688
A 53-year-old man died of sporadic Creutzfeldt-Jakob disease (CJD) after a 1.5-year clinical course. Four and a half years later, his then 55-year-old widow died from CJD after a 1-month illness. Both patients had typical clinical and neuropathologic features of the disease, and pathognomonic proteinase-resistant amyloid protein ("prion" protein, or PrP) was present in both brains. Neither patient had a family history of neurologic disease, and molecular genetic analysis of their PrP genes was normal. No medical, surgical, or dietary antecedent of CJD was identified; therefore, we are left with the unanswerable alternatives of human-to-human transmission or the chance occurrence of sporadic CJD in a husband and wife. 相似文献
32.
A number of studies have examined bradykinin-induced sensitization of primary afferent neurons to mechanical or thermal stimuli. However, bradykinin-induced sensitization to other chemical stimuli has not been systematically addressed. We used primary cultures of dorsal root ganglion neurons from neonatal rats to determine whether bradykinin alters the responsiveness of individual neurons to capsaicin and protons. An increase in the concentration of free intracellular Ca2+ was used as a measure of a response to capsaicin or low pH. Pretreatment with bradykinin (30 nM) increased the proportion of "intermediate-size" (240-320 microm2) dorsal root ganglion neurons that responded to capsaicin (100 nM) or low pH (6.1). However, among "small-size" (160-239 microm2) neurons, bradykinin increased the proportion of neurons that responded to low pH (6.1) but not to capsaicin (10 or 100 nM). Because treatment with arachidonic acid (10 microM) did not mimic the effect of bradykinin and inhibition of cyclo-oxygenase and lipoxygenase with 5,8,11,14-eicosatetraynoic acid (10 microM) did not inhibit the effect of bradykinin on the response to capsaicin, it is not likely that the bradykinin-induced enhancement of neuronal responsiveness is mediated by arachidonic acid or its metabolites in this model. These results support the hypothesis that bradykinin sensitizes primary afferent neurons to other chemicals such as protons that are present in inflamed tissue, particularly by recruiting additional sensory neurons to respond to a given chemical stimulus. An increase in the number of responsive nociceptors that innervate inflamed tissue would contribute to hyperalgesia via spatial summation on spinal neurons in the pathway for pain. Furthermore, since bradykinin enhanced the responsiveness of small-size neurons that responded to protons but not to capsaicin, these data suggest that bradykinin-induced sensitization to protons and capsaicin occur by different mechanisms. 相似文献
33.
Three projective personality tests were used to assess attitude to aggression (The Identification Test), anxiety and defenses (The Meta-Contrast Technique) and creative functioning (The Creative Functioning Test) in 70 patients with breast cancer. Discriminant analyses were applied pro primo to characterize psychologically patients with a better prognosis and patients with a poorer prognosis. A second aim was to characterize psychologically older (postmenopausal) and younger (premenopausal) women. Generally, high scores on the Identification Test indicated maladaptive attitudes towards aggression among all the patients. Patients with a poorer prognosis showed responses that in healthy subjects indicate acknowledgement of aggressive impulses, perhaps suggesting lack of "defenses" against such impulses among those patients. Another way to describe it would be that patients with a better prognosis seem to have (normally nonadaptive) "defenses" against aggressive impulses while those with poorer prognosis have not. Surprisingly, the patients with a better prognosis (but not those with a poorer prognosis) gave responses classified as depression in the Meta-Contrast Technique. Typical of premenopausal patients were responses classified as anxiety as well as reaction formation on the Identification Test. Responses classified as adaptive defenses (isolation) were seen in the Meta-Contrast Technique. A surprising finding was that many of these patients were characterized by high scores on the creativity test. These original statistically significant findings of attitudes towards aggression and creative functioning in breast cancer patients are discussed in relation to the underlying nature of aggression and creativity. 相似文献
34.
Robin Murphy Dylan Shell Amy Guerin Brittany Duncan Benjamin Fine Kevin Pratt Takis Zourntos 《Autonomous Robots》2011,30(2):143-156
Seven flying robot “fairies” joined human actors in the Texas A&;M production of William Shakespeare’s A Midsummer Night’s Dream. The production was a collaboration between the departments of Computer Science and Engineering, Electrical and Computer Engineering, and Theater Arts. The collaboration was motivated by two assertions. First, that the performing arts have principles for creating believable agents that will transfer to robots. Second, the theater is a natural testbed for evaluating the response of untrained human groups (both actors and the audience) to robots interacting with humans in shared spaces, i.e., were believable agents created? The production used two types of unmanned aerial vehicles, an AirRobot 100-b quadrotor platform about the size of a large pizza pan, and six E-flite Blade MCX palm-sized toy helicopters. The robots were used as alter egos for fairies in the play; the robots did not replace any actors, instead they were paired with them. The insertion of robots into the production was not widely advertised so the audience was the typical theatergoing demographic, not one consisting of people solely interested technology. The use of radio-controlled unmanned aerial vehicles provides insights into what types of autonomy are needed to create appropriate affective interactions with untrained human groups. The observations from the four weeks of practice and eight performances contribute (1) a taxonomy and methods for creating affect exchanges between robots and untrained human groups, (2) the importance of improvisation within robot theater, (3) insights into how untrained human groups form expectations about robots, and (4) awareness of the importance of safety and reliability as a design constraint for public engagement with robot platforms. The taxonomy captures that apparent affect can be created without explicit affective behaviors by the robot, but requires talented actors to convey the situation or express reactions. The audience’s response to robot crashes was a function of whether they had the opportunity to observe how the actors reacted to robot crashes on stage, suggesting that pre-existing expectations must be taken into account in the design of autonomy. Furthermore, it appears that the public expect robots to be more reliable (an expectation of consumer product hardening) and safe (an expectation from product liability) than the current capabilities and this may be a major challenge or even legal barrier for introducing robots into shared public spaces. These contributions are expected to inform design strategies for increasing public engagement with robot platforms through affect, and shows the value of arts-based approaches to public encounters with robots both for generating design strategies and for evaluation. 相似文献
35.
J Zhuang T Droma S Sun C Janes RE McCullough RG McCullough A Cymerman SY Huang JT Reeves LG Moore 《Canadian Metallurgical Quarterly》1993,74(1):303-311
Lifelong high-altitude residents of North and South America acquire blunted hypoxic ventilatory responses and exhibit decreased ventilation compared with acclimatized newcomers. The ventilatory characteristics of Himalayan high-altitude residents are of interest in the light of their reportedly lower hemoglobin levels and legendary exercise performance. Until recently, Sherpas have been the only Himalayan population available for study. To determine whether Tibetans exhibited levels of ventilation and hypoxic ventilatory drives that were as great as acclimatized newcomers, we compared 27 lifelong Tibetan residents of Lhasa, Tibet, China (3,658 m) with 30 acclimatized Han ("Chinese") newcomers matched for age, body size, and extent of exercise training. During room air breathing, minute ventilation was greater in the Tibetan than in the Han young men because of an increased respiratory frequency, but arterial O2 saturation and end-tidal PCO2 did not differ, indicating similar levels of effective alveolar ventilation. The Tibetan subjects had higher hypoxic ventilatory response shape parameter A values and hypercapnic ventilatory responsiveness than the Han subjects. Among the Han subjects, duration of high-altitude residence correlated with the degree of blunting of the hypoxic ventilatory drive. Paradoxically, hyperoxia (inspired O2 fraction 0.70) increased minute ventilation and decreased end-tidal PCO2 in the Tibetan but not in the Han men. We concluded that lifelong Tibetan residents of high altitude neither hypoventilated nor exhibited blunted hypoxic ventilatory responses compared with acclimatized Han newcomers, suggesting that the effects of lifelong high-altitude residence on ventilation and ventilatory response to hypoxia differ in Tibetan compared with other high-altitude populations. 相似文献
36.
IA Andriashvili RSh Adamiia LI Kvachadze TG Melitauri LG Pataridze 《Canadian Metallurgical Quarterly》1977,42(2):300-305
The composition of nitrous bases of phage FI-1 DNA was studied. As is evidenced from the values of buoyant density in CsCl (p=1,7093 g/cm(3)), melting temperature (T degrees m=86,05 degrees), spectral parameters and direct chromatographic determination, the DNA analysed contains 41,5 mole% pairs of guanine-cystosine. 5-hydroxymethylcytosine and other anomalous bases were not found. Chemical identification and jaxtposition of data of buoyant density in CsCl and Cs2SO4 (p=1,4466 g/cm(3)) and T degrees m. showed the presence of the extra-sugar component in DNA, most likely in the form of hentibiose. Spectral character of thermal denaturation of DNA in different solvents is indicative of the double helixity of its structure. DNA is characterized by enthalpies of conformational transitions "helix coil" (deltaH=12,3 kcal/g) and (deltaH=10 kcal/g) for the solvents, 1 x SSC, and 0,1 x SSC, correspondingly. The presence of extra-sugar in DNA with standard set of nitrous bases is discussed. 相似文献
37.
The trial record in an antitrust case against the Oregon State Medical Society, finally decided in 1952, was examined to reconstruct the behavior of a competitive market for health insurance coverage. Health insurers, called "hospital associations," were found to have engaged individually in cost-control efforts similar to, but possibly more aggressive than, today's utilization review under professional sponsorship. The subsequent disappearance of these insurer-initiated cost controls in Oregon is traced to the medical society's organization of a competing Blue Shield plan as a model of insurer conduct and to a simultaneous boycott by physicians of the hospital associations as long as they persisted in questioning doctors' practices. Some modern parallels are noted, and the advantages of fostering privately sponsored cost-control efforts are suggested. 相似文献
38.
LG Kupchinski? IuA Barshte?n BG Pogodaev AI Treshinski? 《Canadian Metallurgical Quarterly》1976,(3):80-84
A study was made of a possibility of using Soviet made membranes "Vladipor" with a pore diameter of 16--17 nm for the purpose of concentration and purification of antigenic extracts from stab cultures of S. typhi obtained by the action of typsin, hydrogen peroxide and detergents. Preparations, complete by antigenic structure, were obtained by ultrafiltration, with a good yield. The maximal rate of ultrafiltration was noted in case of "peroxide" antigenic preparations. The use of diafiltration provided a significant reduction of the ash content in the end products. 相似文献
39.
In this paper, we present the concept of work compatibility as an integrated work design criterion that simultaneously improves human health and safety, productivity, and work quality in manufacturing systems. In this respect, we have modeled work compatibility as a work design parameter that mathematically integrates the energizing (i.e., system resources) and the demand (i.e., system requirements) forces in the work system. A mathematical equation has been derived for the work compatibility matrix. Furthermore, an operating zone has been developed in which there is a region of optimality for the employee to function on practical grounds with a good degree of efficiency and sustainability. An application example is provided to demonstrate the potential of work compatibility to improve productivity and quality along with improvement in worker safety and health. © 2004 Wiley Periodicals, Inc. Hum Factors Man 14: 379–402, 2004. 相似文献
40.
This paper introduces an approach that scales assignment algorithms to large numbers of robots and tasks. It is especially suitable for dynamic task allocations since both task locality and sparsity can be effectively exploited. We observe that an assignment can be computed through coarsening and partitioning operations on the standard utility matrix via a set of mature partitioning techniques and programs. The algorithm mixes centralized and decentralized approaches dynamically at different scales to produce a fast, robust method that is accurate and scalable, and reduces both the global communication and unnecessary repeated computation. An allocation results by operating on each partition: either the steps are repeated recursively to refine the generalized assignment, or each sub-problem may be solved by an existing algorithm. The results suggest that only a minor sacrifice in solution quality is needed for significant gains in efficiency. The algorithm is validated using extensive simulation experiments and the results show advantages over the traditional optimal assignment algorithms. 相似文献