169 research outputs found
Regional science at the turn of the century: Reflections on its epistemological status
As a contribution to the current debate on the state-of-the art of regional science, this paper presents some reflections on the epistemological and methodological status of the discipline as we approach the turn of the century. First of all, and contrary to the widely held view that quantitative approach is seriously 'in crisis', it is argued that the discipline is going through a period of intensive, but constructive, theoretical development. To support this assertion, the authors suggest that it is important to abandon a hidden source of prejudice: the tendency to evaluate the present situation in terms of an outdated conception of the discipline. Modern quantitative geography and regional science is a vast and varied scientific field, which has radically evolved under the pressure of changing theoretical paradigms and technological advance. It has little to do with the old regional science of the 60s. The first part of the paper reviews this evolution: 1. from the original goal of applying to geography the tools of classical science, such as statistics, optimization and modelling (whose use was made possible in the 60s by the availability of the new "number crunching" computers) 2. to the present informatization (and hence quantification) of all branches of regional science, based on PCs and the Net, used as tools not just for computation, but for data handling, representation, visualization and communication). An attempt is made to fit all of these efforts, those with a long tradition (modelling, O.R., gaming simulation, statistics etc.), as well as the more recent approaches (expert systems, G.I.S., hypermedia, virtual reality, A.I.) into a single framework, stressing the specific aims of each and identifying existing - or potential - interconnections. In the second part of the paper we focus on the new frontiers of regional science and quantitative geography with particular reference to the processes of analysis and planning. It is suggested that: 1. the goal of analysis is shifting from simulation (the explicitation in terms of the "scientific method") of the mental processes involved in problem-solving, to the replication of the human ability to "formulate problems". This implies that creativity, and related aspects such as learning, and expertise, will come increasingly within the scope of research in regional science 2. progress in planning will be limited unless we will be able to go beyond the misleading counterposition between the formalised "rational" approach and the intuitive design approach. A fruitful way to cope with planning in a complex world is to integrate the two strategies and, in doing so, to tap into wider sources of knowledge. In other words, it is important to learn the 'art' of using the tools of geographical science.
Reciprocal Regulation of HSD11B1 and HSD11B2 Predicts Glucocorticoid Sensitivity in Childhood ALL
The impact of 24 weeks of supervised endurance versus resistance exercise training on left ventricular mechanics in healthy untrained humans.
BACKGROUND: In addition to the well-known cardiac structural adaptation to exercise training, little work examined changes in LV mechanics. With new regional and global indices available we sought to determine the effect of 24 weeks endurance versus resistance training on LV mechanics. METHODS AND RESULTS: 23 male subjects were randomly allocated to either a 24-week endurance- or resistance-training program. Pre- and post-training 2D echocardiographic images were acquired. Global LV mechanics (strain [Δ]) were recorded in longitudinal, circumferential and radial planes. Rotation was assessed at apical and basal levels. In addition, longitudinal Δ-volume loops, across the cardiac cycle, were constructed from simultaneous LV Δ (longitudinal and transverse strain) and volume measurements across the cardiac cycle as a novel measure of LV mechanics. Marginal differences in Δ and rotation data were found between groups. Post-training, we found no change in global peak Δ data. Peak basal rotation significantly increased after training with changes in the endurance group (-2.2±1.9o to -4.5±3.3o) and the resistance group (-2.9±3.0o to -3.4±2.9o) . LV Δ-volume loops revealed a modest rightward shift in both groups. CONCLUSIONS: Whilst most global and regional indices of LV mechanics were not significantly altered, 24 weeks of intense supervised exercise training increased basal rotation. Further studies that assess LV mechanics in larger cohorts of subjects and those with cardiovascular disease and risk factors may reveal important training impacts
Short-Term Outcomes in Elderly Patients with SARS-CoV-2 Infections Discharged from Community Hospitals
open access journalIntroduction: Clinical outcomes from very elderly hospitalised patients with SARS-COV-2 (Covid-19), are
poor, with a reported in-patient mortality as high as 20%. Age, sex, comorbidities, ethnicity and deprivation
have all been shown to correlate with worse outcomes in patients with Covid-19, however the outcomes of
elderly hospitalised patients once discharged remains unknown. We looked at our cohort of very elderly
patients treated within community hospital settings.
Methods & Results: A retrospective case note analysis was undertaken within our 222 bedded community
hospital structure during the first wave of the pandemic from April to August 2020. A total of 129 patients
were treated during this period. The average age of the patients was 78.8 ± 2.7 years. In patient mortality
was 11% (14 patients). 83% of patients were discharged from the hospitals. 27% were discharged to care
home facilities. At 90 days, 83% of patients were still alive but a third of these patients were re-admitted into
hospital with various different diagnoses.
Conclusion: Elderly patients who survived Covid-19 infection and left hospital have a relatively high
mortality rate in the short-term. Also connected with this is a high morbidity rate and therefore care must be
directed within primary care to ensure that this group stay out of hospital
Vitamin B12 Deficiency and Hyperhomocysteinemia in Outpatients with Stroke or Transient Ischemic Attack: a cohort study at an academic medical centre
Objective We sought to assess the current magnitude of the opportunity for secondary stroke prevention with B vitamins. Design A cohort study. Setting The Urgent TIA (Transient Ischaemic Attack) Clinic at an academic medical centre. Main outcome measures We assessed the prevalence of biochemical vitamin B 12 deficiency (B 12 Def, serum B 12 \u3c156 pmol/L), hyperhomocysteinaemia (HHcy; plasma total homocysteine [tHcy] \u3e14 ÎŒmol/L) and metabolic B 12 deficiency (MetB 12 Def, serum B 12 \u3c258 pmol/L and HHcy) between 2002 and 2017, by age group and by stroke subtype. Results Data were available in 4055 patients. B 12 Def was present in 8.2% of patients overall; it declined from 10.9% of patients referred before 2009 to 5.4% thereafter (p=0.0001). MetB 12 Def was present in 10.6% of patients, and HHcy was present in 19.1% of patients. Among the patients aged â„80 years, MetB 12 Def was present in 18.1% and HHcy in 35%. Among the 3410 patients whose stroke subtype was determined, HHcy was present in 18.4% of patients: 23.3% of large artery atherosclerosis, 18.1% of cardioembolic, 16.3% of small vessel disease, 10.8% of other unusual aetiologies and 13.6% of undetermined subtypes (p=0.0001). Conclusions Despite a decline in our referral area since 2009, B 12 Def, MetB 12 Def and HHcy remain common in patients with stroke/TIA. Because these conditions are easily treated and have serious consequences, all patients with stroke/TIA should have their serum B 12 and tHcy measured
Distinct Effects of Blood Flow and Temperature on Cutaneous Microvascular Adaptation
Aims: We performed two experiments to determine whether cutaneous microvascular adaptations in response to repeated core temperature elevation are mediated by increases in skin temperature, and/or, skin blood flow. Methods: Healthy subjects participated for 8-weeks in thrice-weekly bouts of 30mins lower limb heating (40°C). In Study 1, both forearms were âclampedâ at basal skin temperature throughout each heating bout (n=9). Study 2 involved identical lower limb heating, with the forearms under ambient conditions (unclamped, n=10). In both studies, a cuff was inflated around one forearm during the heating bouts to assess the contribution of skin blood flow and temperature responses. We assessed forearm skin blood flow responses to both lower limb (systemic reflex) heating, and to local heating of the forearm skin, pre and post intervention. Results: Acutely, lower limb heating increased core temperature (Study 1: +0.63±0.15°C, Study 2: +0.69±0.19°C, P<0.001) and forearm skin blood flow (Study 1: 10±3 vs 125±44, Study 2: 16±9 vs 136±41 PU, P<0.001), with skin responses significantly attenuated in the cuffed forearm (P<0.01). Skin blood flow responses to local heating decreased in Study 1 (clamped forearms, week 0vs8: 1.46±0.52 vs 0.99±0.44 CVC, P<0.05), whereas increases occurred in Study 2 (unclamped; week 0vs8: 1.89±0.57 vs 2.27±0.52 CVC, P<0.05). Cuff placement abolished local adaptations in both studies. Conclusion: Our results indicate that repeated increases in skin blood flow and skin temperature result in increased skin flux responses to local heating, whereas repeated increases in skin blood flow in the absence of change in skin temperature induced the opposite response. Repeated increases in core temperature induce intrinsic microvascular changes, the nature of which are dependent upon both skin blood flow and skin temperature
Left ventricular morphology and function in adolescents: Relations to fitness and fatness.
BACKGROUND: Obesity in childhood predisposes individuals to cardiovascular disease and increased risk of premature all-cause mortality. The aim of this study was to determine differences in LV morphology and function in obese and normal-weight adolescents. Furthermore, relationships between LV outcomes, cardiorespiratory fitness (CRF) and adiposity were explored. METHODS: LV morphology was assessed using magnetic resonance imaging (MRI) in 20 adolescents (11 normal-weight [BMI equivalent to 18kg/m(2)-25kg/m(2)] and 9 obese [BMI equivalent to â„30kg/m(2)]); 13.3±1.1years, 45% female, Tanner puberty stage 3 [2-4]) using magnetic resonance imaging (MRI). Global longitudinal strain (GLS), strain rate (SR) and traditional echocardiographic indices were used to assess LV function. CRF (peak oxygen consumption), percent body fat (dual-energy x-ray absorptiometry), abdominal adipose tissue (MRI), and blood biochemistry markers were also evaluated. RESULTS: Adolescents with obesity showed significantly poorer LV function compared to normal-weight adolescents (P0.05). Moderate to strong associations between myocardial contractility and relaxation, adiposity, arterial blood pressure and cardiorespiratory fitness were noted (r=0.49-0.71, P<0.05). CONCLUSION: Obesity in adolescence is associated with altered LV systolic and diastolic function. The notable relationship between LV function, CRF and adiposity highlights the potential utility of multidisciplinary lifestyle interventions to treat diminished LV function in this population. CLINICAL TRIAL REGISTRATION: NCT01991106
The Effect of Water Immersion during Exercise on Cerebral Blood Flow
Introduction: Regular exercise induces recurrent increases in cerebrovascular perfusion. In peripheral arteries, such episodic increases in perfusion are responsible for improvement in arterial function and health. We examined the hypothesis that exercise during immersion augments cerebral blood flow velocity compared with intensity-matched land-based exercise.
Methods: Fifteen normotensive participants were recruited (26 ± 4 yr, 24.3 ± 1.9 kg·mâ2). We continuously assessed mean arterial blood pressure, HR, stroke volume, oxygen consumption, and blood flow velocities through the middle and posterior cerebral arteries before, during, and after 20-min bouts of water- and land-based stepping exercise of matched intensity. The order in which the exercise conditions were performed was randomized between subjects. Water-based exercise was performed in 30°C water to the level of the right atrium.
Results: The water- and land-based exercise bouts were closely matched for oxygen consumption (13.3 mL·kgâ1·minâ1 (95% confidence interval (CI), 12.2â14.6) vs 13.5 mL·kgâ1·minâ1 (95% CI, 12.1â14.8), P = 0.89) and HR (95 bpm (95% CI, 90â101) vs 96 bpm (95% CI, 91â102), P = 0.65). Compared with land-based exercise, water-based exercise induced an increase in middle cerebral artery blood flow velocity (74 cm·sâ1 (95% CI, 66â81) vs 67 cm·sâ1 (95% CI, 60â74) P < 0.001), posterior cerebral artery blood flow velocity (47 cm·sâ1 (95% CI, 40â53) vs 43 cm·sâ1 (95% CI, 37â49), P < 0.001), mean arterial blood pressure (106 mm Hg (95% CI, 100â111) vs 101 mm Hg (95% CI, 95â106), P < 0.001), and partial pressure of expired CO2 (P †0.001).
Conclusions: Our findings suggest that water-based exercise augments cerebral blood flow, relative to land-based exercise of similar intensity, in healthy humans
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