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101.
A rigorous global recursive formulation is developed for the dynamics of a classical articulated tree. The system in question
is composed of rigid parts interconnected by spring loaded single hinges to form a tree. The global formulation addresses
the dynamics of complete branches (subtrees). The external moments applied to the branch are brought to bear on the instantaneous
moment of inertia of the branch. Corrections for deviations from rigidity are accumulated recursively from sub-branches. The
translational motion is likewise treated by addressing the structure as a whole and accumulating effects of internal motion
recursively. Global recursive dynamics is a rigorous reexpression of the equations of motion of the system in terms that are,
at the same time, intuitive and directly computable. Applied sequentially, global recursive dynamics gives rise to a family
of approximations, progressing from the rigid to the fully articulated, which converge to the solution as the time step tends
to zero. 相似文献
102.
Guglietti Crissa L.; Rosen Barry; Murphy K. Joan; Laframboise Stephane; Dodge Jason; Ferguson Sarah; Katz Joel; Ritvo Paul 《Canadian Metallurgical Quarterly》2010,7(4):266
This study assessed posttraumatic stress disorder (PTSD) in women being investigated for an ovarian cancer diagnosis to determine prevalence and factors predicting PTSD in these patients. Participants (N = 75) were recruited from the Princess Margaret Hospital in Toronto, Ontario, after their initial clinic appointment and given a prediagnostic assessment that included measures of PTSD, depression, stress and pain. One month later, patients received an identical postdiagnostic assessment. No cases of clinical PTSD were detected, although 13.6% of participants were identified with subsyndromal PTSD. Multiple regression analyses showed that those participants reporting significant baseline depressive symptoms, definitively diagnosed with ovarian cancer, and with shorter treatment wait times were more likely to have a significant increase in PTSD symptoms. Supportive interventions aimed at reducing PTSD symptoms, launched prior to an ovarian cancer diagnosis, might optimally be directed at patients with baseline depressive symptoms and those with shorter treatment wait times. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
103.
Detailed knowledge of the petroleum systems of mature petroleum provinces is often lacking. This has often resulted from the early discovery of most of these provinces' reserves. The South Caspian basin represents one such province. The “modern” era of petroleum exploration in the South Caspian began more than 100 years ago. Even with this long history several aspects of the petroleum system have remained largely speculation. Among the key questions are:
- • What is the primary hydrocarbon source for the region?
- • Where and when has hydrocarbon generation taken place?
- • Can exploration be extended beyond known stratigraphic and areal limits?
104.
Cost-effectiveness of providing insurance benefits for posthospital psychiatric halfway house stays.
Coursey Robert D.; Ward-Alexander Lucia; Katz Bonnie 《Canadian Metallurgical Quarterly》1990,45(10):1118
A model insurance benefit package for posthospitalization psychiatric halfway house care was developed and administered to 32 hospitalized mentally ill persons. The therapeutic and cost effectiveness of providing a 120-day benefit package was examined over a 14-mo posthospitalization period. This was compared with the effectiveness of hospitalization benefits alone for the same patients over the 42 mo prior to halfway house admission. In terms of therapeutic efficacy, there was no significant deterioration after hospitalization release in either the symptom or behavioral coping scales, except for an increase in somatization. Yearly hospital recidivism rates fell from 79% to 29%, and the average yearly length of hospital stay per patient fell from 83 days to 18 days. In terms of cost-effectiveness, halfway house benefits saved the insurers 59% of their hospitalization costs. The implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
105.
Faculty teaching computer science courses-to majors and nonmajors alike-may have little chance to evaluate the historical material found in the texts assigned to their students. There are problems, however, in the presentations of the history of the field in many current texts, problems of which faculty are not always aware. Clarification of some of the problematic historical material found in current texts is presented, and some suggestions are offered for additional topics that should be included in the history component of the computer science curriculum. The examples are gleaned from several texts that have been otherwise valuable and effective in the presentation of computer science material; indeed, their continued presence and wide usage attest to the quality of their presentation. But the history of the field deserves the same careful treatment in these texts as do other aspects of computer science 相似文献
106.
Katz Lori S.; Snetter Miatta R.; Robinson Athena Hagler; Hewitt Paul; Cojucar Geta 《Canadian Metallurgical Quarterly》2008,45(2):186
Holographic reprocessing (HR) facilitates holistic reappraisal of attributions regarding interpersonal violence and maltreatment. The authors tested the feasibility to train therapists to run a protocol using HR to reduce negative thoughts associated with posttraumatic stress disorder (PTSD) in women veterans who have had sexual trauma or abuse. The study assessed pre- and postscores on the Posttraumatic Cognitions Inventory (PTCI) in a naturalistic clinical setting with 5 therapists. The protocol consisted of screening for PTSD, followed by an average of 9 HR treatment sessions. Twenty-two women were referred to the study; 17 enrolled and completed treatment (0% dropout rate). Significant decreases were found on all scales of the PTCI, with large effect sizes: total negative thoughts, t(16) = 4.42, p 相似文献
107.
PB Kruger S Mathews M Katz KR Aggarwala S Nowbotsing 《Canadian Metallurgical Quarterly》1997,37(18):2511-2526
Accommodation was monitored continuously under open-loop conditions while subjects viewed a sinusoidally oscillating sine-wave grating (0.2 Hz; +/- 1 D; 2.7 c/d; 0.56 contrast) in a Badal optometer. The target was illuminated by monochromatic light (590 nm) or white light (3000 K) with longitudinal chromatic aberration (LCA) normal, doubled, neutralized and reversed. Subjects (12) accommodated well in white light with LCA normal and doubled (mean gains = 0.85 and 0.94), gain was reduced in the neutralized condition (0.54), in monochromatic light (0.43), and especially when LCA was reversed (0.30). The results suggest that accommodation responds to changes in the relative contrast of spectral components of the retinal image and perhaps to the vergence of light. 相似文献
108.
109.
W Pruzanski E Bogoch A Katz M Wloch E Stefanski B Grouix G Sakotic P Vadas 《Canadian Metallurgical Quarterly》1995,22(11):2114-2119
OBJECTIVE: Secretory nonpancreatic phospholipase A2 (sPLA2) is a known inducer/promoter of the inflammatory process in the joints. It correlates with disease activity in adult and juvenile rheumatoid arthritis. Synovial fluids contain high concentrations of sPLA2. We discovered that human articular cartilage contains large quantities of sPLA2 and that culture chondrocytes constitutively synthesize and release sPLA2. To test the mechanism controlling the release of sPLA2, we exposed cultured human articular chondrocytes to cytokines and other agents, known to induce sPLA2 in other cells. METHODS: Chondrocytes obtained from cartilage of normal appearance from rheumatoid and osteoarthritic joints, and from normal, neonatal joints were compared to rabbit articular chondrocytes. Radiolabeled Escherichia coli derived phospholipid assay and ELISA technique using monoclonal antibodies against recombinant human synovial type sPLA2 were employed. The cells were grown as monolayers as well as in alginate beads. RESULTS: Human articular chondrocytes from both arthritic and neonatal joints released sPLA2 constitutively but could not be further stimulated with interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha), IL-6, oncostatin M, lipopolysaccharide (LPS), or forskolin. Marked stimulation was observed when the cells were exposed to 8-bromo cyclic adenosine monophosphate (cAMP). Growing the cells as monolayers or in alginate beads did not change the results. In contrast to human cells, rabbit chondrocytes responded to IL-1 beta and IL-1/TNF, but not to TNF-alpha alone, with a very marked increase in extracellular sPLA2 activity. CONCLUSION: Human articular chondrocytes synthesize and constitutively release sPLA2. Such continuous release is most probably responsible for the high concentration of sPLA2 in articular cartilage and may be the source of synovial fluid sPLA2. To our knowledge, human articular chondrocytes are the only sPLA2 producing cells tested to date that do not respond to cytokine stimulation with increased sPLA2 activity; yet enhancement was seen with 8-bromo cAMP. It seems therefore that, human articular chondrocytes possess signalling mechanisms for the release of sPLA2 unlike those from other mammalian cells. The significance of this observation remains to be elucidated. 相似文献
110.