1,779 research outputs found
Space construction system analysis. Part 2: Platform definition
The top level system requirements are summarized and the accompanying conceptual design for an engineering and technology verification platform (ETVP) system is presented. An encompassing statement of the system objectives which drive the system requirements is presented and the major mission and subsystem requirements are described with emphasis on the advanced communications technology mission payload. The platform design is defined and used as a reference configuration for an end to space construction analyses. The preferred construction methods and processes, the important interactions between the platform design and the construction system design and operation, and the technology development efforts required to support the design and space construction of the ETVP are outlined
Energy-resolved electron-spin dynamics at surfaces of p-doped GaAs
Electron-spin relaxation at different surfaces of p-doped GaAs is
investigated by means of spin, time and energy resolved 2-photon photoemission.
These results are contrasted with bulk results obtained by time-resolved
Faraday rotation measurements as well as calculations of the Bir-Aronov-Pikus
spin-flip mechanism. Due to the reduced hole density in the band bending region
at the (100) surface the spin-relaxation time increases over two orders of
magnitude towards lower energies. At the flat-band (011) surface a constant
spin relaxation time in agreement with our measurements and calculations for
bulk GaAs is obtained.Comment: 6 pages, 4 figure
Selective decline of 5-HT1A receptor binding sites in rat cortex, hippocampus and cholinergic basal forebrain nuclei during aging
The effect of aging on 5-HT1A receptor binding in several forebrain areas associated with the basal forebrain cholinergic system was investigated in rats of 3-, 24- and 30-months-old by receptor autoradiography and biochemical binding assay using [H-3]8-OH-DPAT as a ligand. Autoradiographic measurements demonstrated a marked region-specific decline of ligand binding in: (i) regions of the basal forebrain cholinergic cell groups, i.e. the medial septum, diagonal band nuclei and magnocellular nucleus basalis, (ii) the frontal and parietal neocortex and (iii) the dentate gyrus of the hippocampus. No change or- only a slight decrease of the 5-HT1A receptor density was found in other areas investigated: the CA1 and CA3 sectors of hippocampus, the cingular and perirhinal cerebral cortex and the lateral septum. The autoradiographic findings were substantiated by the biochemical binding assay, which revealed a comparable loss of 5-HT1A receptor in the hippocampus and neocortex at the age of 30 months. The results clearly show that with increasing age the decrement of 5-HT1A receptor binding in the rat forebrain is remarkably region-selective and particularly affects the cholinergic cell groups that innervate cortex and hippocampus. This phenomenon appears to be especially significant in relation to the neuronal substrates underlying the age-related alterations of mood and cognition. (C) 1997 Elsevier Science B.V
Vocational perspectives after spinal cord injury
Objective: To give insight into the vocational situation several years after a traumatic spinal cord injury (SCI) and describe the personal experiences and unmet needs; to give an overview of health and functional status per type of SCI and their relationship with employment status. Design: Descriptive analysis of data from a questionnaire. Setting: Dutch rehabilitation centre with special department for patients with spinal cord injuries. Subjects: Fifty-seven patients with a traumatic SCI, aged 18-60 years, admitted to the rehabilitation centre from 1990 to 1998. Main measures: Questionnaire with items related to vocational outcome, job experiences, health and functional status. Results: Of 49 patients who were working at the moment of SCI 60% currently had a paid job. Vocational outcome was related to a higher educational level. A significant relation between the SCI-specific health and functional status and employment was not found. The respondents who changed to a new employer needed more time to resume work, but seemed more satisfied with the job and lost fewer working hours than those who resumed work with the same employer. In spite of reasonable to good satisfaction with the current work situation, several negative experiences and unmet needs were reported. Conclusions: Despite a high participation in paid work following SCI, the effort of the disabled worker to have and keep a job should not be underestimated
A statistical study of BRIs (SMCs), isolated substorms, and individual sawtooth injections
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95420/1/jgra19762.pd
Nodular Regenerative Hyperplasia Secondary to Neoadjuvant Chemotherapy for Colorectal Liver Metastases
Liver resection is the only curative treatment for patients with colorectal liver metastases (CLMs). Neoadjuvant chemotherapy can improve resectability but has a potential harmful effect on the nontumorous liver. Patients with chemotherapy-induced hepatic injury undergoing liver surgery have higher risks of post-resectional morbidity. We present two cases of patients without pre-existent liver disease treated with oxaliplatin-based chemotherapy followed by surgical resection of their CLMs. Their intra-operative liver specimen showed morphologic abnormalities characteristic of nodular regenerative hyperplasia (NRH). NRH led to portal hypertension in both patients that resulted in deleterious post-resectional complications and death of one patient. Interestingly, the other patient underwent two repeat nonanatomic liver resections because of recurrent CLMs. The intra-operative liver specimen still showed signs of NRH and sinusoidal congestion, but the post-resectional courses were uneventful. Nevertheless, caution is recommended in patients with suspected NRH. Careful volumetric analysis should guide the operative strategy. When future remnant liver volume is regarded insufficient, portal vein embolization or restrictive surgery should be considered
Exploring the relation between preoperative physical functioning and the impact of major complications in patients following pancreatic resection
BACKGROUND: This study aimed to evaluate the association between preoperative level of physical functioning and time to recovery of physical functioning, postoperative complications, and the impact of postoperative major complications in patients undergoing elective pancreatic resection. Additionally, prediction models to identify high-risk patients for developing a major complication were externally validated. METHODS: Perioperative data of patients who underwent pancreatic resection were analysed. Primary outcomes were time to recovery of physical functioning and postoperative major complications. Impact of a major complication was explored by evaluating its effect on time to recovery of physical functioning. Risk-prediction models were retrieved following a systematic review. RESULTS: Multivariable analysis (n = 63) showed that ASA grade III (OR 3.498) and preoperative platelet count (OR 1.005) were associated with major complications, whereas aerobic capacity (OR 0.347) was associated with time to recovery of physical functioning. Age, preoperative aerobic capacity, functional mobility, and perceived level of functional capacity were associated with the impact of a major complication. The AUC of two risk prediction models were 0.556 and 0.701. CONCLUSION: Preoperative parameters of physical function were associated with postoperative outcomes and may be useful in outcome prediction, although future approaches should not only register the incidence of major complications but also take the impact of a complication on a patient's physical functioning into account
An exploratory cluster randomised trial of a university halls of residence based social norms marketing campaign to reduce alcohol consumption among 1st year students
<p>Aims: This exploratory trial examines the feasibility of implementing a social norms marketing campaign to reduce student drinking in universities in Wales, and evaluating it using cluster randomised trial methodology.</p>
<p>Methods: Fifty residence halls in 4 universities in Wales were randomly assigned to intervention or control arms. Web and paper surveys were distributed to students within these halls (n = 3800), assessing exposure/contamination, recall of and evaluative responses to intervention messages, perceived drinking norms and personal drinking behaviour. Measures included the Drinking Norms Rating Form, the Daily Drinking Questionnaire and AUDIT-C.</p>
<p>Results: A response rate of 15% (n = 554) was achieved, varying substantially between sites. Intervention posters were seen by 80% and 43% of students in intervention and control halls respectively, with most remaining materials seen by a minority in both groups. Intervention messages were rated as credible and relevant by little more than half of students, though fewer felt they would influence their behaviour, with lighter drinkers more likely to perceive messages as credible. No differences in perceived norms were observed between intervention and control groups. Students reporting having seen intervention materials reported lower descriptive and injunctive norms than those who did not.</p>
<p>Conclusions: Attention is needed to enhancing exposure, credibility and perceived relevance of intervention messages, particularly among heavier drinkers, before definitive evaluation can be recommended. A definitive evaluation would need to consider how it would achieve sufficient response rates, whilst hall-level cluster randomisation appears subject to a significant degree of contamination.</p>
Stigma and Social Power: Expecting to Interact with an Obese Person Activates Power in the Self-concept
People's sense of power is often a more crucial determinant of their behavior than their actual level of power. In this paper, we suggest that individuals may perceive themselves as more powerful when anticipating interaction with a member of a stigmatized out-group than with a member of a nonstigmatized group. Normal weight participants (N = 77) expected to have an interaction with a target randomly identified as obese or thin. Participants were quicker to endorse words describing themselves in terms of traits associated with power when the target was obese than thin. They were also likely to expect greater interpersonal power, to endorse more negative attitudes towards obese people and to form more negative impressions, if the target was obese rather than thin. These findings suggest that a perception of empowerment is spontaneously activated prior to interaction with an obese person.http://www.informaworld.com/smpp/content~db=all~content=a907123882~frm=titlelinkSCOPUS: ar.jinfo:eu-repo/semantics/publishe
- …