269 research outputs found
Applying KAM Theory to Highly Eccentric Orbits
This research applies KAM theory to highly eccentric orbits for earth orbiting satellites by using spectral methods to find the three basis frequencies resulting from earth\u27s geopotential. Once a torus is created from these frequencies, its dynamics data can be compared to the position data of an integrated data set over multiple orbit types, specifically, orbits with varying eccentricity. The analysis shows that many eccentric orbits are actually KAM tori when the only perturbation is the earth\u27s geopotential. The residuals agree to 10s of meters in most cases. This research also outlines many of the limitations of the current method and gives recommendations for further study and real-world applications. Applications focus on space debris and non-operational satellites
Анализ разработки и выбора способа эксплуатации Сугмутского нефтяного месторождения (ЯНАО)
Целью данной выпускной квалификационной работы является изучение состояния разработки месторождения, степени реализации проектных решений и предложения по совершенствованию процесса разработки месторожденияThe purpose of this final qualifying work is to study the state of development, the degree of implementation of design solutions and proposals for improving the development of field
Interaction of pregnancy-specific glycoprotein 1 with integrin Α5β1 is a modulator of extravillous trophoblast functions
Human pregnancy-specific glycoproteins (PSGs) serve immunomodulatory and pro-angiogenic functions during pregnancy and are mainly expressed by syncytiotrophoblast cells. While PSG mRNA expression in extravillous trophoblasts (EVTs) was reported, the proteins were not previously detected. By immunohistochemistry and immunoblotting, we show that PSGs are expressed by invasive EVTs and co-localize with integrin α5. In addition, we determined that native and recombinant PSG1, the most highly expressed member of the family, binds to α5β1 and induces the formation of focal adhesion structures resulting in adhesion of primary EVTs and EVT-like cell lines under 21% oxygen and 1% oxygen conditions. Furthermore, we found that PSG1 can simultaneously bind to heparan sulfate in the extracellular matrix and to α5β1 on the cell membrane. Wound healing assays and single-cell movement tracking showed that immobilized PSG1 enhances EVT migration. Although PSG1 did not affect EVT invasion in the in vitro assays employed, we found that the serum PSG1 concentration is lower in African-American women diagnosed with early-onset and late-onset preeclampsia, a pregnancy pathology characterized by shallow trophoblast invasion, than in their respective healthy controls only when the fetus was a male; therefore, the reduced expression of this molecule should be considered in the context of preeclampsia as a potential therapy
The effectiveness and cost-effectiveness of assistive technology and telecare for independent living in dementia: a randomised controlled trial
OBJECTIVES: The use of assistive technology and telecare (ATT) has been promoted to manage risks associated with independent living in people with dementia but with little evidence for effectiveness. METHODS: Participants were randomly assigned to receive an ATT assessment followed by installation of all appropriate ATT devices or limited control of appropriate ATT. The primary outcomes were time to institutionalisation and cost-effectiveness. Key secondary outcomes were number of incidents involving risks to safety, burden and stress in family caregivers and quality of life. RESULTS: Participants were assigned to receive full ATT (248 participants) or the limited control (247 participants). After adjusting for baseline imbalance of activities of daily living score, HR for median pre-institutionalisation survival was 0.84; 95% CI, 0.63 to 1.12; P = 0.20. There were no significant differences between arms in health and social care (mean -£909; 95% CI, -£5,336 to £3,345, P = 0.678) and societal costs (mean -£3,545; 95% CI, -£13,914 to £6,581, P = 0.499). ATT group members had reduced participant-rated quality-adjusted life years (QALYs) at 104 weeks (mean - 0.105; 95% CI, -0.204 to -0.007, P = 0.037) but did not differ in QALYs derived from proxy-reported EQ-5D. DISCUSSION: Fidelity of the intervention was low in terms of matching ATT assessment, recommendations and installation. This, however, reflects current practice within adult social care in England. CONCLUSIONS: Time living independently outside a care home was not significantly longer in participants who received full ATT and ATT was not cost-effective. Participants with full ATT attained fewer QALYs based on participant-reported EQ-5D than controls at 104 weeks
The impact of assistive technology on burden and psychological well-being in informal caregivers of people with dementia (ATTILA Study)
INTRODUCTION: Assistive technology and telecare (ATT) may alleviate psychological burden in informal caregivers of people with dementia. This study assessed the impact of ATT on informal caregivers’ burden and psychological well‐being. METHODS: Individuals with dementia and their informal caregivers were recruited to a randomized‐controlled trial assessing effectiveness of ATT. Caregivers were allocated to two groups according to their cared‐for person's randomization to a full or basic package of ATT and were assessed on caregiver burden, state anxiety, and depression. Caregivers’ data from three assessments over 6 months of the trial were analyzed. RESULTS: No significant between‐ or within‐group differences at any time point on caregivers’ burden, anxiety, and depression levels were found. DISCUSSION: Full ATT for people with dementia did not impact caregivers’ psychological outcomes compared to basic ATT. The length of follow up was restricted to 6 months
Rapid carbon accumulation at a saltmarsh restored by managed realignment exceeded carbon emitted in direct site construction
Increasing attention is being paid to the carbon sequestration and storage services provided by coastal blue carbon ecosystems such as saltmarshes. Sites restored by managed realignment, where existing sea walls are breached to reinstate tidal inundation to the land behind, have considerable potential to accumulate carbon through deposition of sediment brought in by the tide and burial of vegetation in the site. While this potential has been recognised, it is not yet a common motivating factor for saltmarsh restoration, partly due to uncertainties about the rate of carbon accumulation and how this balances against the greenhouse gases emitted during site construction. We use a combination of field measurements over four years and remote sensing to quantify carbon accumulation at a large managed realignment site, Steart Marshes, UK. Sediment accumulated rapidly at Steart Marshes (mean of 75 mm yr-1) and had a high carbon content (4.4% total carbon, 2.2% total organic carbon), resulting in carbon accumulation of 36.6 t ha-1 yr-1 total carbon (19.4 t ha-1 yr-1 total organic carbon). This rate of carbon accumulation is an order of magnitude higher than reported in many other restored saltmarshes, and is somewhat higher than values previously reported from another hypertidal system (Bay of Fundy, Canada). The estimated carbon emissions associated with the construction of the site were ~2–4% of the observed carbon accumulation during the study period, supporting the view that managed realignment projects in such settings may have significant carbon accumulation benefits. However, uncertainties such as the origin of carbon (allochthonous or autochthonous) and changes in gas fluxes need to be resolved to move towards a full carbon budget for saltmarsh restoration
Social work and gender::An argument for practical accounts
This article contributes to the debate on gender and social work by examining dominant approaches within the field. Anti-discriminatory, woman-centered and intersectional accounts are critiqued for reliance upon both reification and isolation of gender. Via examination of poststructural, queer and trans theories within social work, the author then presents accounts based upon structural/materialist, ethnomethodological and discursive theories, in order to open up debates about conceptualization of gender. These are used to suggest that social work should adopt a focus on gender as a practical accomplishment that occurs within various settings or contexts
Report and preliminary results of SONNE Cruise SO 145/2 [SO145/2], Talcahuano (Chile) - Arica (Chile), February 4 - February 29, 2000
Effects of an adapted physical activity program in a group of elderly subjects with flexed posture: clinical and instrumental assessment
<p>Abstract</p> <p>Background</p> <p>Flexed posture commonly increases with age and is related to musculoskeletal impairment and reduced physical performance. The purpose of this clinical study was to systematically compare the effects of a physical activity program that specifically address the flexed posture that marks a certain percentage of elderly individuals with a non specific exercise program for 3 months.</p> <p>Methods</p> <p>Participants were randomly divided into two groups: one followed an Adapted Physical Activity program for flexed posture and the other one completed a non-specific physical activity protocol for the elderly. A multidimensional clinical assessment was performed at baseline and at 3 months including anthropometric data, clinical profile, measures of musculoskeletal impairment and disability. The instrumental assessment of posture was realized using a stereophotogrammetric system and a specific biomechanical model designed to describe the reciprocal position of the body segments on the sagittal plane in a upright posture.</p> <p>Results</p> <p>The Adapted Physical Activity program determined a significant improvement in several key parameters of the multidimensional assessment in comparison to the non-specific protocol: decreased occiput-to-wall distance, greater lower limb range of motion, better flexibility of pectoralis, hamstrings and hip flexor muscles, increased spine extensor muscles strength. Stereophotogrammetric analysis confirmed a reduced protrusion of the head and revealed a reduction in compensative postural adaptations to flexed posture characterized by knee flexion and ankle dorsiflexion in the participants of the specific program.</p> <p>Conclusion</p> <p>The Adapted Physical Activity program for flexed posture significantly improved postural alignment and musculoskeletal impairment of the elderly. The stereophotogrammetric evaluation of posture was useful to measure the global postural alignment and especially to analyse the possible compensatory strategies at lower limbs in flexed posture.</p
The role of heterodimerization between VEGFR-1 and VEGFR-2 in the regulation of endothelial cell homeostasis
VEGF-A activity is tightly regulated by ligand and receptor availability. Here we investigate the physiological function of heterodimers between VEGF receptor-1 (VEGFR-1; Flt-1) and VEGFR-2 (KDR; Flk-1) (VEGFR(1-2)) in endothelial cells with a synthetic ligand that binds specifically to VEGFR(1-2). The dimeric ligand comprises one VEGFR-2-specific monomer (VEGF-E) and a VEGFR-1-specific monomer (PlGF-1). Here we show that VEGFR(1-2) activation mediates VEGFR phosphorylation, endothelial cell migration, sustained in vitro tube formation and vasorelaxation via the nitric oxide pathway. VEGFR(1-2) activation does not mediate proliferation or elicit endothelial tissue factor production, confirming that these functions are controlled by VEGFR-2 homodimers. We further demonstrate that activation of VEGFR(1-2) inhibits VEGF-A-induced prostacyclin release, phosphorylation of ERK1/2 MAP kinase and mobilization of intracellular calcium from primary endothelial cells. These findings indicate that VEGFR-1 subunits modulate VEGF activity predominantly by forming heterodimer receptors with VEGFR-2 subunits and such heterodimers regulate endothelial cell homeostasis
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