138 research outputs found
Pared-down landscapes in Antarctica
No full textThe frigid-arid climate that now prevails in ice-free parts of Victoria Land, Antarctica, inhibits glacial erosion. If certain landscapes, more or less remote from the great troughs of outlet glaciers, have been glaciated in the past, as seems very probable, landforms that resulted from glaciation have been replaced by surfaces of different origin.
A widespread landscape glaciation was probably contemporaneous with the excavation of large cirques which still survive in mountain summit areas.
Replacement of glaciated landforms by others, in a general paring down of the land surface to forms of moderate relief, seems to have resulted from the process of gravity removal of debris from precipitous rock outcrops that were retreating because of disintegration by salt weathering and were eventually eliminated, in most cases, so that the landscape became a mosaic of smooth denudation slopes inclined at 33° to 350.
In the Darwin Mountains ice-free area (80ºS) an advanced stage of such denudation with respect to a base level some 400 m above the present level of surrounding glaciers has produced some pyramidal landforms. Just above the present ice level, however, narrow Richter denudation slopes that border weathering rock faces are at only a juvenile stage of development. Thus the ice level appears to have stood alternately at about its present position and 400 m higher in Pleistocene interglacials and glacial ages respectively. The higher ice levels must have been due to extensions of the ice sheet seaward caused by groundings of the shelf ice during low glacio-eustatic stands of sea leve
A generatív tervezés biomechanikai alkalmazásának lehetőségei
No full textA „genaratív tervezés” során a termékkel szemben támasztott követelményeket összegezzük az elvárt funkciók megadásával, pontosítva: a funkcióknak megfelelő paraméterekkel írjuk le, mit szeretnénk létrehozni. A tervezési folyamat során különféle szempontok szerinti optimalizálást is végezhetünk, így a kiinduló feltételeknek megfelelő lehetséges megoldások közül választhatjuk ki a számunkra megfelelő valóságos változatot. Megfelelő adatbázisok birtokában a mesterséges intelligencia (AI) használatával számos új alkalmazási lehetőségre nyílik olyan területeken, mint az egészségügy, a pénzügy, a közlekedés és az oktatás. A biomechanika tudományterületén a mesterséges intelligencia javíthatja az emberi test működésének megértését, új ismereteket nyújthat a sérülések és betegségek diagnosztizálásához, kezeléséhez, megelőzéséhez. A mesterséges intelligenciát olyan alkalmazásokhoz használhatjuk, mint például a kép- és mozgáselemzés, a sérülésveszély előrejelzése, az adatgyűjtés, előfeldolgozás, jellemző kivonatolás, algoritmusképzés, modellérvényesítés és telepítés folyamata. E tanulmány célja, hogy betekintést engedjen a generatív tervezés - adott esetben mesterséges intelligenciát is felhasználó, - biomechanika területét érintő lehetőségeibe
Thromboembolism and toxic shock syndrome: A case presentation and literature update
No full textA case of progressive shock and multisystem organ failure is reported for an 18 year old Lebanese woman, clinically diagnosed as toxic shock syndrome (TSS). The patient developed cough and dyspnea during hospitalization; chest CT angiography revealed thromboembolism of the pulmonary artery. CBC analysis showed leukocytosis with a white cell count (WCC) with a marked increase in PT and PTT coupled with reduced protein S, antithrombin III, and protein C levels. The patient improved gradually and was discharged from the hospital 7 days later on oral anticoagulation, and was followed up for six months with no disease recurence or complications. To our knowledge, this is the first reported case in the literature of toxic shock syndrome associated with pulmonary thromboembolism. © 2004 Kluwer Academic Publishers.Aihara M, 1997, INTERNAL MED, V36, P97, DOI 10.2169-internalmedicine.36.97; AMBROSE RE, 1992, CLIN RADIOL, V45, P355, DOI 10.1016-S0009-9260(05)80096-0; CRAMER SF, 1995, HUM PATHOL, V26, P1157, DOI 10.1016-0046-8177(95)90281-3; DAIL DH, 1988, PULMONARY PATHOLOGY, P677; Eriksson BKG, 1998, CLIN INFECT DIS, V27, P1428, DOI 10.1086-515012; GRONIOWSKI J, 1963, ARCH PATHOL, V101, P230; HERZER CM, 2001, AM BOARD FAM PRACT, V14, P131; HESSELVIK JF, 1991, THROMB HAEMOSTASIS, V65, P126; Horlander KR, 2003, ARCH INTERN MED, V163, P1711, DOI 10.1001-archinte.163.14.1711; JOSELSON R, 1983, HUM PATHOL, V14, P88, DOI 10.1016-S0046-8177(83)80052-5; LARKIN SM, 1982, ANN INTERN MED, V96, P858; Levi M, 1999, NEW ENGL J MED, V341, P586, DOI 10.1056-NEJM199908193410807; MARRARO G, 1991, CANCER, V67, P696, DOI 10.1002-1097-0142(19910201)67:3696::AID-CNCR28206703283.0.CO;2-V; Mesters RM, 1996, BLOOD, V88, P881; Raumanns J, 1995, ANAESTHESIST, V44, P869, DOI 10.1007-s001010050224; REINGOLD AL, 1982, ANN INTERN MED, V96, P871; REINGOLD AL, 1982, ANN INTERN MED, V96, P875; ROBBOY SJ, 1972, HUM PATHOL, V3, P327, DOI 10.1016-S0046-8177(72)80034-0; Sharma S, 2003, CURR OPIN PULM MED, V9, P199, DOI 10.1097-00063198-200305000-00008; Slotman GJ, 2000, SHOCK, V14, P101, DOI 10.1097-00024382-200014020-00004; TODD JK, 1987, LANCET, V2, P1116; TODD JK, 1982, ANN INTERN MED, V96, P83911
Mediated, moderated and direct effects of country of residence, age, and gender on the cognitive and social determinants of adolescent smoking in Spain and the UK: a cross-sectional study
No full textBackground
European trans-national adolescent smoking prevention interventions based on social influences approaches have had limited success. The attitudes-social influences-efficacy (ASE) model is a social cognition model that states smoking behaviour is determined by smoking intention which, in turn, is predicted by seven ASE determinants; disadvantages, advantages, social acceptance, social norms, modelling, perceived pressure, self-efficacy. Distal factors such as country of residence, age and gender are external to the model. The ASE model is, thus, closely related to the Theory of Planned Behaviour. This study assessed the utility of the ASE model using cross-sectional data from Spanish and UK adolescents.
Methods
In 1997, questionnaires were simultaneously administered to Spanish (n = 3716) and UK adolescents (n = 3715) who were considered at high risk of smoking. Participants' age, gender, smoking intentions and ASE determinant scores were identified and linear regression analysis was used to examine the mediated, moderated and direct effects of country of residence, age and gender on participants' smoking intentions.
Results
All UK participants were aged 12 or 13 and most Spanish participants were aged between 12 and 14 (range 12–16 years). Amongst 12 and 13 year olds, regular smoking was more common in Spain. Almost half the participants were female (47.2% in Spain; 49.9% in the UK). Gender did not vary significantly according to age.
The distribution of ASE determinant scores varied by country and predicted intention. The influence of each ASE determinant on intention was moderated by country. Country had a large direct influence on intention (1.72 points on a 7 point scale) but the effects of age and gender were mediated by the ASE determinants.
The findings suggest resisting peer pressure interventions could potentially influence smoking amongst UK adolescents but not Spanish adolescents. Interventions that promote self-efficacy, on the other hand, would possibly have a greater influence on smoking amongst Spanish adolescents.
Conclusion
The ASE model may not capture important cultural factors related to adolescent smoking and the relative contribution of particular ASE determinants to adolescent smoking intentions may differ between countries. Future European trans-national adolescent smoking prevention programmes may benefit from greater undestanding of country-level cultural norms
How do index patients participating in genetic screening programmes for familial hypercholesterolemia (FH) interpret their DNA results?:A UK-based qualitative interview study
No full textOBJECTIVE: To explore patients' interpretations of their DNA results for familial hypercholesterolemia (FH). METHODS: In-depth interviews were conducted with patients from two lipid clinics in Scotland, who were offered genetic testing as part of a nationwide cascade screening service. RESULTS: Patients were receptive to taking part in genetic screening and most expected a positive result. Receiving a molecular diagnosis of FH could provide reassurance to patients that diet and lifestyle factors were not the primary causes of their condition. Patients who received inconclusive results tended to interpret this as meaning that their high cholesterol was not genetic, which could induce feelings of uncertainty and self-blame. With the exception of newly diagnosed patients, for whom a positive result could provide a useful rationale for initiating statins, most perceived DNA screening to be of little relevance to their own medication use or their own approaches to lifestyle management. CONCLUSIONS: Index patients are likely to view DNA screening for FH as non-threatening. Receiving a positive DNA result can be reassuring for patients. Patients may not, however, interpret inconclusive DNA results correctly. PRACTICE IMPLICATIONS: Health professionals need to ensure FH index patients are prepared to receive, and fully understand, inconclusive DNA results
A proteomic investigation of Fusobacterium nucleatum alkaline-induced biofilms
No full textBackground: The Gram negative anaerobe Fusobacterium nucleatum has been implicated in the aetiology of periodontal diseases. Although frequently isolated from healthy dental plaque, its numbers and proportion increase in plaque associated with disease. One of the significant physico-chemical changes in the diseased gingival sulcus is increased environmental pH. When grown under controlled conditions in our laboratory, F. nucleatum subspecies polymorphum formed mono-culture biofilms when cultured at pH 8.2. Biofilm formation is a survival strategy for bacteria, often associated with altered physiology and increased virulence. A proteomic approach was used to understand the phenotypic changes in F. nucleatum cells associated with alkaline induced biofilms. The proteomic based identification of significantly altered proteins was verified where possible using additional methods including quantitative real-time PCR (qRT-PCR), enzyme assay, acidic end-product analysis, intracellular polyglucose assay and Western blotting. Results: Of 421 proteins detected on two-dimensional electrophoresis gels, spot densities of 54 proteins varied significantly (p < 0.05) in F. nucleatum cultured at pH 8.2 compared to growth at pH 7.4. Proteins that were differentially produced in biofilm cells were associated with the functional classes; metabolic enzymes, transport, stress response and hypothetical proteins. Our results suggest that biofilm cells were more metabolically efficient than planktonic cells as changes to amino acid and glucose metabolism generated additional energy needed for survival in a sub-optimal environment. The intracellular concentration of stress response proteins including heat shock protein GroEL and recombinational protein RecA increased markedly in the alkaline environment. A significant finding was the increased abundance of an adhesin, Fusobacterial outer membrane protein A (FomA). This surface protein is known for its capacity to bind to a vast number of bacterial species and human epithelial cells and its increased abundance was associated with biofilm formation. Conclusion: This investigation identified a number of proteins that were significantly altered by F. nucleatum in response to alkaline conditions similar to those reported in diseased periodontal pockets. The results provide insight into the adaptive mechanisms used by F. nucleatum biofilms in response to pH increase in the host environment.Jactty Chew, Peter S Zilm, Janet M Fuss and Neville J Gull
Comorbidity Forces Physiotherapists to Deviate from Guideline Recommendations Resulting in Various Treatments for the Same Patient: A Vignette Study
No full text?Rational, aims and objectives: The aim of this Vignette study was to assess whether physiotherapists (PTs) make reasoned adaptations to evidence-based treatment recommendations when co-morbidity influences single disease treatment. Method: To study the influence of co-morbidity on treatment recommendations, 3 vignettes were created based on authentic patient data. In the first vignette, a patient with a single-diseased Intermittent Claudication (IC) was described, in the second vignette, co-morbidity Chronic Obstructive Pulmonary Disease (COPD) was added. In the third vignette, Knee Osteoarthritis (OA) was additionally added. Therapists described 3 treatment plans and their decision rationale. A random selection of 100 Dutch Claudication Network members was invited to participate in this qualitative study. Results: The response rate was 61%. Thirty percent of the physical therapists did not adjust treatment despite co-morbidity. Another 30% partly adapted the treatment plan when co-morbidity was added to the vignette. The presence of co-morbidity induced 40% to abandon guideline recommendations and to create an individualised treatment plan based on the health needs of the vignette patient. Conclusion: This study showed that the majority of PTs makes adaptations to otherwise evidence-based recommendations when co-morbidity is present in order to tailor treatment to the specific needs of the individual patient. However, the same patient was treated in various ways by different PTs
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