TDRSS S-shuttle unique receiver equipment

Beginning with STS-9, the Tracking and Date Relay Satellite system (TDRSS) will start providing S- and Ku-band communications and tracking support to the Space Shuttle and its payloads. The most significant element of this support takes place at the TDRSS White Sands Ground Terminal, which processes the Shuttle return link S- and Ku-band signals. While Ku-band hardware available to other TDRSS users is also applied to Ku-Shuttle, stringent S-Shuttle link margins have precluded the application of the standard TDRSS S-band processing equipment to S-Shuttle. It was therfore found necessary to develop a unique S-Shuttle Receiver that embodies state-of-the-art digital technology and processing techniques. This receiver, developed by Motorola, Inc., enhances link margins by 1.5 dB relative to the standard S-band equipment and its bit error rate performance is within a few tenths of a dB of theory. An overview description of the Space Shuttle Receiver Equipment (SSRE) is presented which includes the presentation of block diagrams and salient design features. Selected, measured performance results are also presented

The confidence-accuracy relationship for eyewitness reports

Legal decision makers tend to believe that highly confident witnesses are more accurate than less confident witnesses. Furthermore, research suggests that confidence judgements can provide a useful indicator of the accuracy of witnesses’ identification decisions. Yet little research has examined the relationship between eyewitness confidence and accuracy when witnesses recall details about a crime. The experiments in this thesis therefore aimed to examine the factors that influence the relationship between the accuracy of witnesses’ memory reports and their confidence in those reports, and to further our understanding of how witnesses make confidence judgements. Part One of this thesis examines several factors that may affect the relationship between confidence and accuracy when witnesses report their memories of a crime. The results of Experiments 1-3 indicate that witnesses’ confidence judgements can provide a useful indicator of their memory accuracy regardless of whether they are collected immediately after each response or at the end of the memory test. Experiment 1 also indicates that the confidence-accuracy relationship can remain strong when memory performance is impaired by poor visibility, but Experiment 2 suggests that the relationship between confidence and accuracy breaks down when witnesses are exposed to misinformation. Experiment 4 explores the effect of retention interval and self-rated memory ability on the confidence-accuracy relationship. The results suggest that relatively long retention intervals can impair the confidence-accuracy relationship, but people’s perception of their everyday memory ability has little impact on the confidence-accuracy relationship. Part Two examines the confidence-accuracy relationship in the context of cross-examination. The findings suggest that the effect of cross-examination style questions on eyewitness accuracy depends on the question type and eyewitness confidence. Together, the findings presented in this thesis help to refine theories of eyewitness confidence and highlight potential issues for using confidence judgements to assess eyewitness accuracy in real cases

New mission requirements methodologies for services provided by the Office of Space Communications

The Office of Space Communications, NASA Headquarters, has recently revised its methodology for receiving, accepting and responding to customer requests for use of that office's tracking and communications capabilities. This revision is the result of a process which has become over-burdened by the size of the currently active and proposed missions set, requirements reviews that focus on single missions rather than on mission sets, and negotiations most often not completed early enough to effect needed additions to capacity or capability prior to launch. The requirements-coverage methodology described is more responsive to project/program needs and provides integrated input into the NASA budget process early enough to effect change, and describes the mechanisms and tools in place to insure a value-added process which will benefit both NASA and its customers. Key features of the requirements methodology include the establishment of a mechanism for early identification of and systems trades with new customers, and delegates the review and approval of requirements documents to NASA centers in lieu of Headquarters, thus empowering the system design teams to establish and negotiate the detailed requirements with the user. A Mission Requirements Request (MRR) is introduced to facilitate early customer interaction. The expected result is that the time to achieve an approved set of implementation requirements which meet the customer's needs can be greatly reduced. Finally, by increasing the discipline in requirements management, through the use of base lining procedures, a tighter coupling between customer requirements and the budget is provided. A twice-yearly projection of customer requirements accommodation, designated as the Capacity Projection Plan (CPP), provides customer feedback allowing the entire mission set to be serviced

Rupture de fibre : comparaison entre un modèle écrit a l'échelle microstructural et une détection du phénomène par tomographie très haute résolution

International audienceOn présente dans cette étude la discrimination des phénomènes de ruptures de fibre, de microfissuration intralaminaire, de macrofissuration intralaminaire ainsi que du microdélaminage au sein des composites stratifiés d'unidirectionnels orientés, dans le cadre d'une méthode de détection des endommagements basée sur la technique de l'Emission Acoustique. Ces résultats expérimentaux sont confrontés aux prévisions issues d'un modèle de comportement de matériaux composites unidirectionnels, basés sur la physique des phénomènes à l'échelle des constituants

Long retention intervals impair the confidence-accuracy relationship for eyewitness recall

A growing body of research suggests that confidence judgments can provide a useful indicator of memory accuracy under some conditions. One factor known to affect eyewitness accuracy, yet rarely examined in the confidence–accuracy literature, is retention interval. Using calibration analyses, we investigated how retention interval affects the confidence–accuracy relationship for eyewitness recall. In total, 611 adults watched a mock crime video and completed a cued-recall test either immediately, after 1 week, or after 1 month. Long (1 month) delays led to lower memory accuracy, lower confidence judgments, and impaired the confidence–accuracy relationship compared to shorter (immediate and 1 week) delays. Long-delay participants who reported very high levels of confidence tended to be overconfident in the accuracy of their memories compared to other participants. Self-rated memory ability, however, did not predict eyewitness confidence or the confidence–accuracy relationship. We discuss the findings in relation to cue-utilization theory and a retrieval–fluency account

Associations between the misinformation effect, trauma exposure and symptoms of posttraumatic stress disorder and depression

This research aimed to conduct an initial investigation into the relationships between the “misinformation effect” and trauma exposure, posttraumatic stress disorder (PTSD) and depression. Study 1 was a pilot study developing an online misinformation paradigm that could assess the influence of emotion and arousal on memory distortions. Participants (n = 162, Mage = 39.90; SD = 10.90) were recruited through TurkPrime. In Study 2 community members (n = 116, Mage = 28.96; SD = 10.33) completed this misinformation paradigm and measures of trauma exposure, PTSD, and depression. Study 1 found memory for central details was better for high-arousal than low-arousal and neutral-arousal images. Peripheral memory appeared worse for negative and neutral images than positive images. Study 2 found trauma exposure and PTSD symptoms predicted the misinformation effect; greater trauma exposure was associated with a greater proportion of errors, while PTSD was associated with a lower proportion of errors. Valence and arousal did not influence these associations. These findings have important implications in clinical and legal contexts where individuals with a history of trauma, or who are experiencing symptoms of PTSD or depression, are often required to recall emotionally-laden events. There is a surprising dearth of research into the misinformation effect in clinical populations and further research is required

Photoelasticity of crystalline and amorphous silica from first principles

Based on density-functional perturbation theory we have computed from first principles the photoelastic tensor of few crystalline phases of silica at normal conditions and high pressure (quartz, $\alpha$-cristobalite, $\beta$-cristobalite) and of models of amorphous silica (containig up to 162 atoms), obtained by quenching from the melt in combined classical and Car-Parrinello molecular dynamics simulations. The computational framework has also been checked on the photoelastic tensor of crystalline silicon and MgO as prototypes of covalent and ionic systems. The agreement with available experimental data is good. A phenomenological model suitable to describe the photoelastic properties of different silica polymorphs is devised by fitting on the ab-initio data.Comment: ten figure

Bursts in a fiber bundle model with continuous damage

We study the constitutive behaviour, the damage process, and the properties of bursts in the continuous damage fiber bundle model introduced recently. Depending on its two parameters, the model provides various types of constitutive behaviours including also macroscopic plasticity. Analytic results are obtained to characterize the damage process along the plastic plateau under strain controlled loading, furthermore, for stress controlled experiments we develop a simulation technique and explore numerically the distribution of bursts of fiber breaks assuming infinite range of interaction. Simulations revealed that under certain conditions power law distribution of bursts arises with an exponent significantly different from the mean field exponent 5/2. A phase diagram of the model characterizing the possible burst distributions is constructed.Comment: 9 pages, 11 figures, APS style, submitted for publicatio

Food safety in hospital: knowledge, attitudes and practices of nursing staff of two hospitals in Sicily, Italy

BACKGROUND: Food hygiene in hospital poses peculiar problems, particularly given the presence of patients who could be more vulnerable than healthy subjects to microbiological and nutritional risks. Moreover, in nosocomial outbreaks of infectious intestinal disease, the mortality risk has been proved to be significantly higher than the community outbreaks and highest for foodborne outbreaks. On the other hand, the common involvement in the role of food handlers of nurses or domestic staff, not specifically trained about food hygiene and HACCP, may represent a further cause of concern. The purpose of this study was to evaluate knowledge, attitudes, and practices concerning food safety of the nursing staff of two hospitals in Palermo, Italy. Association with some demographic and work-related determinants was also investigated. METHODS: The survey was conducted, by using a semi-structured questionnaire, in March-November 2005 in an acute general hospital and a paediatric hospital, where nursing staff is routinely involved in food service functions. RESULTS: Overall, 401 nurses (279, 37.1%, of the General Hospital and 122, 53.5%, of the Paediatric Hospital, respectively) answered. Among the respondents there was a generalized lack of knowledge about etiologic agents and food vehicles associated to foodborne diseases and proper temperatures of storage of hot and cold ready to eat foods. A general positive attitude towards temperature control and using clothing and gloves, when handling food, was shared by the respondents nurses, but questions about cross-contamination, refreezing and handling unwrapped food with cuts or abrasions on hands were frequently answered incorrectly. The practice section performed better, though sharing of utensils for raw and uncooked foods and thawing of frozen foods at room temperatures proved to be widely frequent among the respondents. Age, gender, educational level and length of service were inconsistently associated with the answer pattern. More than 80% of the respondent nurses did not attend any educational course on food hygiene. Those who attended at least one training course fared significantly better about some knowledge issues, but no difference was detected in both the attitude and practice sections. CONCLUSION: Results strongly emphasize the need for a safer management of catering in the hospitals, where non professional food handlers, like nursing or domestic staff, are involved in food service functions

Effects of asenapine on depressive symptoms in patients with bipolar I disorder experiencing acute manic or mixed episodes: a post hoc analysis of two 3-week clinical trials

<p>Abstract</p> <p>Background</p> <p>Asenapine demonstrated superiority over placebo for mania in bipolar I disorder patients experiencing acute current manic or mixed episodes in 2 randomized, placebo-and olanzapine-controlled trials. We report the results of exploratory pooled post hoc analyses from these trials evaluating asenapine's effects on depressive symptoms in patients from these trials with significant baseline depressive symptoms.</p> <p>Methods</p> <p>In the original trials (A7501004 [NCT00159744], A7501005 [NCT00159796]), 977 patients were randomized to flexible-dose sublingual asenapine (10 mg twice daily on day 1; 5 or 10 mg twice daily thereafter), placebo, or oral olanzapine 5-20 mg once daily for 3 weeks. Three populations were defined using baseline depressive symptoms: (1) Montgomery-Asberg Depression Rating Scale (MADRS) total score ≥20 (n = 132); (2) Clinical Global Impression for Bipolar Disorder-Depression (CGI-BP-D) scale severity score ≥4 (n = 170); (3) diagnosis of mixed episodes (n = 302) by investigative site screening. For each population, asenapine and olanzapine were independently compared with placebo using least squares mean change from baseline on depressive symptom measures.</p> <p>Results</p> <p>Decreases in MADRS total score were statistically greater with asenapine versus placebo at days 7 and 21 in all populations; differences between olanzapine and placebo were not significant. Decreases in CGI-BP-D score were significantly greater with asenapine versus placebo at day 7 in all categories and day 21 in population 1; CGI-BP-D score reductions were significantly greater with olanzapine versus placebo at day 21 in population 1 and day 7 in populations 2 and 3.</p> <p>Conclusions</p> <p>These post hoc analyses show that asenapine reduced depressive symptoms in bipolar I disorder patients experiencing acute manic or mixed episodes with clinically relevant depressive symptoms at baseline; olanzapine results appeared to be less consistent. Controlled studies of asenapine in patients with acute bipolar depression are necessary to confirm the generalizability of these findings.</p