1,696 research outputs found
B-52 stability augmentation system reliability
The B-52 SAS (Stability Augmentation System) was developed and retrofitted to nearly 300 aircraft. It actively controls B-52 structural bending, provides improved yaw and pitch damping through sensors and electronic control channels, and puts complete reliance on hydraulic control power for rudder and elevators. The system has experienced over 300,000 flight hours and has exhibited service reliability comparable to the results of the reliability test program. Development experience points out numerous lessons with potential application in the mechanization and development of advanced technology control systems of high reliability
River Discharge, in State of the Climate in 2008
The global mean temperature in 2008 was slightly cooler than that in 2007; however, it still ranks within the 10 warmest years on record. Annual mean temperatures were generally well above average in South America, northern and southern Africa, Iceland, Europe, Russia, South Asia, and Australia. In contrast, an exceptional cold outbreak occurred during January across Eurasia and over southern European Russia and southern western Siberia. There has been a general increase in land-surface temperatures and in permafrost temperatures during the last several decades throughout the Arctic region, including increases of 1° to 2°C in the last 30 to 35 years in Russia. Record setting warm summer (JJA) air temperatures were observed throughout Greenland
U.S. River Discharge for 2008 in State of the Climate in 2008
The global mean temperature in 2008 was slightly cooler than that in 2007; however, it still ranks within the 10 warmest years on record. Annual mean temperatures were generally well above average in South America, northern and southern Africa, Iceland, Europe, Russia, South Asia, and Australia. In contrast, an exceptional cold outbreak occurred during January across Eurasia and over southern European Russia and southern western Siberia. There has been a general increase in land-surface temperatures and in permafrost temperatures during the last several decades throughout the Arctic region, including increases of 1° to 2°C in the last 30 to 35 years in Russia. Record setting warm summer (JJA) air temperatures were observed throughout Greenland
Methane emissions from western Siberian wetlands: heterogeneity and sensitivity to climate change
The prediction of methane emissions from high-latitude wetlands is important given concerns about their sensitivity to a warming climate. As a basis for the prediction of wetland methane emissions at regional scales, we coupled the variable infiltration capacity macroscale hydrological model (VIC) with the biosphereâenergy-transferâhydrology terrestrial ecosystem model (BETHY) and a wetland methane emissions model to make large-scale estimates of methane emissions as a function of soil temperature, water table depth, and net primary productivity (NPP), with a parameterization of the sub-grid heterogeneity of the water table depth based on TOPMODEL. We simulated the methane emissions from a 100 km Ă 100 km region of western Siberia surrounding the Bakchar Bog, for a retrospective baseline period of 1980â1999 and have evaluated their sensitivity to increases in temperature of 0â5 °C and increases in precipitation of 0â15%. The interactions of temperature and precipitation, through their effects on the water table depth, played an important role in determining methane emissions from these wetlands. The balance between these effects varied spatially, and their net effect depended in part on sub-grid topographic heterogeneity. Higher temperatures alone increased methane production in saturated areas, but caused those saturated areas to shrink in extent, resulting in a net reduction in methane emissions. Higher precipitation alone raised water tables and expanded the saturated area, resulting in a net increase in methane emissions. Combining a temperature increase of 3 °C and an increase of 10% in precipitation to represent climate conditions that may pertain in western Siberia at the end of this century resulted in roughly a doubling in annual emissions
Treatment of breast cancer: Imo State Nigeria versus Indiana, USA women -- comparative analytic study
BACKGROUND:
Women with breast cancer undergo multimodal treatment for best outcome. This study seeks to identify the treatment challenges for such women in Imo State, Nigeria vis-Ă -vis similar women in Indiana USA. We compared the treatment modalities of both groups; noting predictors of compliance for subsequent action.
SETTING:
Federal Medical Centre, Owerri; Imo State, Imo State University, Orlu, Nigeria and Indiana University Hospital, Indiana, USA.
DESIGN:
A retrospective study.
METHODOLOGY:
From 2000-2013, 100 randomly pulled charts of patients treated for pathologically confirmed breast cancer in Imo, Nigeria Federal Medical Centre Owerri, Imo State University Hospital; and Indiana University Hospital U.S. respectively were reviewed. The demographics, clinical and pathological data of the patients with confirmed breast cancer were obtained. The data were formatted and analyzed with SPSS version 16.0. The clinical features, management options, outcomes and specific features were compared for both groups using Wilcoxon Rank Sum tests (age, parity) and chi-square tests for all other variables. A 5% significance level was used for all tests.
RESULTS:
One hundred patients were included for each group. The mean/minimum ages; Imo, Nigeria 41.7/21 (SD/SE 15.3/1.5) vs. Indiana, U.S.56.4/29 (SD 12.4/SE 1.2) p<0.0001. Histology for Indiana USA women was predominantly ductal carcinoma in situ (DCIS) P<0.0001 while that of Imo, Nigeria was invasive ductal carcinoma inflammatory cancer P<0.0326. Women in both locations received chemotherapy and surgery. Imo women received less radiotherapy. Toxicity from chemotherapy remained constant features for both groups, P<0.0001. In Indiana USA, the 5year survival exceeded 85%; In Imo Nigeria it was 10%. This study showed that Women on both locations who were likely to be compliant were those receiving mastectomy; Imo, Nigeria 44(56%) <0.013 vs. Indiana, U.S. 74(80%) p<0.0186; women with cosmesis given; Imo, Nigeria 41(42%) vs. Indiana, U.S. 91 (94%) p<0.0001. Sample sizes were inadequate to perform multivariable models.
CONCLUSION:
The multimodal treatment regimen implied that there was need for an algorithm protocol for breast cancer women. Thus the need to improve the quality of treatment particularly in Nigeria by improved treatment documentation to overcome key barriers involving information exchange
Acoustic allometry revisited: morphological determinants of fundamental frequency in primate vocal production
A fundamental issue in the evolution of communication is the degree to which signals convey accurate (âhonestâ) information about the signaler. In bioacoustics, the assumption that fundamental frequency (fo) should correlate with the body size of the caller is widespread, but this belief has been challenged by various studies, possibly because larynx size and body size can vary independently. In the present comparative study, we conducted excised larynx experiments to investigate this hypothesis rigorously and explore the determinants of fo. Using specimens from eleven primate species, we carried out an inter-specific investigation, examining correlations between the minimum fo produced by the sound source, body size and vocal fold length (VFL). We found that, across species, VFL predicted minimum fo much better than body size, clearly demonstrating the potential for decoupling between larynx size and body size in primates. These findings shed new light on the diversity of primate vocalizations and vocal morphology, highlighting the importance of vocal physiology in understanding the evolution of mammal vocal communication
A qualitative exploration of the effect of visual field loss on daily life in home-dwelling stroke survivors
Objective: To explore the effect of visual field loss on the daily life of community-dwelling stroke survivors. Design: A qualitative interview study. Participants: Adult stroke survivors with visual field loss of at least sixâmonthsâ duration. Methods: Semi-structured interviews were conducted with a non-purposive sample of 12 stroke survivors in their own homes. These were recorded, transcribed verbatim and analyzed with the framework method, using an inductive approach. Results: Two key analytical themes emerged. âPerception, experience and knowledgeâ describes participantâs conflicted experience of having knowledge of their impaired vision but lacking perception of that visual field loss and operating under the assumption that they were viewing an intact visual scene when engaged in activities. Inability to recognize and deal with visual difficulties, and experiencing the consequences, contributed to their fear and loss of self-confidence. âAvoidance and adaptationâ were two typologies of participant response to visual field loss. Initially, all participants consciously avoided activities. Some later adapted to vision loss using self-directed head and eye scanning techniques. Conclusions: Visual field loss has a marked impact on stroke survivors. Stroke survivors lack perception of their visual loss in everyday life, resulting in fear and loss of confidence. Activity avoidance is a common response, but in some, it is replaced by self-initiated adaptive techniques
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Conceptualising quality of life for older people with aphasia
Background: There is an increasing need in speech and language therapy for clinicians to provide intervention in the context of the broader life quality issues for people with aphasia. However, there is no descriptive research that is explicitly focused on quality of life (QoL) from the perspectives of older people with aphasia.
Aims: The current study explores how older people with chronic aphasia who are living in the community describe their QoL in terms of what contributes to and detracts from the quality in their current and future lives. The study is descriptive in nature, and the purpose is to conceptualize the factors that influence QoL.
Methods & Procedures: Thirty older participants (16 women, 14 men) with mild to moderate aphasic impairment took part. All participants had adequate communication skills to participate: demonstrating reliable yes/no response and moderate auditory comprehension ability. Participants were interviewed in their own homes using six brief unprompted open questions about QoL, in a structured interview. The first five questions were drawn from previous gerontological research (Farquhar, 1995), and a sixth question specifically targeting communication was added. Content analysis was used, identifying discrete units of data and then coding these into concepts and factors. Additional demographic information was collected, and participantsâ mood on day of interviewing was assessed using the Geriatric Depression Scale (Sheikh & Yesavage, 1986).
Outcomes & Results: Activities, verbal communication, people, and body functioning were the core factors in QoL for these participants, and they described how these factors both contributed quality in life as well as detracted from life quality. Other factors that influenced QoL included stroke, mobility, positive personal outlook, in/dependence, home and health. Whilst the findings are limited by the lack of probing of participantsâ responses, the study does present preliminary evidence for what is important in QoL to older people with aphasia.
Conclusions: Quality of life for older people with predominantly mild to moderate chronic aphasia who are living in the community is multifactorial in nature. Some factors lie within the remit of speech and language therapy, some lie beyond the professional role, but all are relevant for consideration in rehabilitation and community practice. Further qualitative research is implicated to better understand QoL with aphasia, using in-depth interviewing with a broader range of people with aphasia
Endovascular treatment of a Superior Mesenteric Artery Syndrome variant secondary to traumatic pseudoaneurysm
Pseudoaneurysms related to the superior mesenteric artery (SMA) are a recognised complication of trauma to the vessel, and successful treatment with stenting has been previously described. We report the case of a patient who presented with obstruction of the fourth part of the duodenum secondary to a traumatic pseudoaneurysm, a hitherto unreported variant of superior mesenteric artery syndrome. Exclusion of the pseudoaneurysm and relief of the duodenal obstruction were simultaneously achieved by placement of a covered stent
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