1,685 research outputs found
Microclimate variations between semienclosed and open sections of a marathon route
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The impact of environmental and human factors on urban heat and microclimate variability
Urbanization is known to cause noticeable changes in the properties of local climate. Studies have shown that urban areas, compared to rural areas with less artificial surfaces, register higher local temperatures as a result of Urban Heat Islands (UHIs). Hong Kong is one of the most densely populated cities in the world and a high proportion of its population residing in densely built high-rise buildings are experiencing some degrees of thermal discomfort. This study selected Mong Kok and Causeway Bay, two typical urban communities in Hong Kong, to gather evidence of microclimate variation and sources of thermal discomfort. UHIs were estimated from 58 logging sensors placed at strategic locations to take temperature and humidity measurements over 17 consecutive days each in the summer/hot and winter/cool periods. By employing geographic information and global positioning systems, these measurements were geocoded and plotted over the built landscape to convey microclimate variation. The empirical data were further aligned with distinct environmental settings to associate possible factors contributing to UHIs. This study established the existence and extent of microclimate variation of UHI within urban communities of different environmental configuration and functional uses. The findings provided essential groundwork for further studies of UHI effects to inform sources of local thermal discomfort and better planning design to safeguard environmental health in public areas.postprin
Understanding why metal-on-metal hip arthroplasties fail: a comparison between patients with well-functioning and revised birmingham hip resurfacing arthroplasties. AAOS exhibit selection.
A large proportion of metal-on-metal hip arthroplasty failures are due to unexplained pain. The mechanism of failure has been thought to be associated with factors that increase material loss, including specific design features and surgical positioning of components. However, recent evidence suggests that there is not a simple dose-response relationship. An analysis of failed metal-on-metal hip arthroplasties involving a single design was performed in an attempt to help resolve this issue. Our aim was to identify the clinical and component variables associated with failure of metal-on-metal hip arthroplasties, particularly in patients undergoing revision arthroplasty because of unexplained hip pain, and to clarify the role of material loss
Which circulating antioxidant vitamins are confounded by socioeconomic deprivation? The MIDSPAN family study
<p><b>Background:</b> Antioxidant vitamins are often described as having “independent” associations with risk of cancer, cardiovascular disease (CVD) and mortality. We aimed to compare to what extent a range of antioxidant vitamins and carotenoids are associated with adulthood and childhood markers of socioeconomic deprivation and to adverse lifestyle factors.</p>
<p><b>Methods and Findings:</b> Socioeconomic and lifestyle measures were available in 1040 men and 1298 women from the MIDSPAN Family Study (30–59 years at baseline) together with circulating levels of vitamins A, C, E, and carotenoids (α-carotene, β-carotene, lutein and lycopene). Markers of socioeconomic deprivation in adulthood were consistently as strongly associated with lower vitamin C and carotenoid levels as markers of adverse lifestyle; the inverse association with overcrowding was particularly consistent (vitamin C and carotenoids range from 19.1% [95% CI 30.3–6.0] to 38.8% [49.9–25.3] lower among those in overcrowded residencies). These associations were consistent after adjusting for month, classical CVD risk factors, body mass index, physical activity, vitamin supplements, dietary fat and fibre intake. Similar, but weaker, associations were seen for childhood markers of deprivation. The association of vitamin A or E were strikingly different; several adult adverse lifestyle factors associated with higher levels of vitamin A and E, including high alcohol intake for vitamin A (9.5% [5.7–13.5]) and waist hip ratio for vitamin E (9.5% [4.8–14.4]), with the latter associations partially explained by classical risk factors, particularly cholesterol levels.</p>
<p><b>Conclusions:</b> Plasma vitamin C and carotenoids have strong inverse associations with adulthood markers of social deprivation, whereas vitamin A and E appear positively related to specific adverse lifestyle factors. These findings should help researchers better contextualize blood antioxidant vitamin levels by illustrating the potential limitations associated with making causal inferences without consideration of social deprivation.</p>
Prescriber and Dispenser Perceptions About Antibiotic Use in Acute Uncomplicated Childhood Diarrhea and Upper Respiratory Tract Infection in New Delhi: Qualitative Study
DiarrhoeaOBJECTIVE: The objective of the study was to explore the prescribing practices, knowledge, and attitudes of primary care doctors and community pharmacists, regarding antibiotic use in acute upper respiratory tract infections (URTI) and diarrhea in children to better understand causes of misuse and identify provider suggestions to change such behavior. MATERIALS AND METHODS: Two focus group discussions (FGDs) each were conducted with primary care government doctors (GDs), private general practitioners (GPs), pediatricians, and community pharmacists in Delhi. Each FGD had 8–12 participants and lasted 2 h. Furthermore, 22 individual face‑to‑face semi‑structured interviews were conducted with providers of varying type and experience at their workplaces. Thematic and summative qualitative content analysis was done. RESULTS: All groups admitted to overusing antibiotics, GPs appearing to use more antibiotics than GDs and pediatricians for URTI and diarrhea in children. Pharmacists copy the prescribing of neighborhood doctors. Antimicrobial resistance (AMR) knowledge was poor for all stakeholders except pediatricians. Causes for prescribing antibiotics were patient pressure, profit motive, lack of follow‑up and in addition for GDs, workload, no diagnostic facility, and pressure to use near‑expiry medicines. Knowledge was gained through self‑experience, copying others, information from pharmaceutical companies, and for some, training, continuous medical education/conferences. All groups blamed other professional groups/quacks for antibiotic overuse. Interventions suggested were sensitizing and empowering prescribers through training of providers and the public about the appropriate antibiotic use and AMR and implementing stricter regulations. CONCLUSIONS: A package of interventions targeting providers and consumers is urgently needed for awareness and change in behavior to reduce inappropriate community antibiotic use
Teosinte Inflorescence Phytolith Assemblages Mirror Zea Taxonomy
Molecular DNA analyses of the New World grass (Poaceae) genus Zea, comprising five species, has resolved taxonomic issues including the most likely teosinte progenitor (Zea mays ssp. parviglumis) of maize (Zea mays ssp. mays). However, archaeologically, little is known about the use of teosinte by humans both prior to and after the domestication of maize. One potential line of evidence to explore these relationships is opaline phytoliths produced in teosinte fruit cases. Here we use multidimensional scaling and multiple discriminant analyses to determine if rondel phytolith assemblages from teosinte fruitcases reflect teosinte taxonomy. Our results indicate that rondel phytolith assemblages from the various taxa, including subspecies, can be statistically discriminated. This indicates that it will be possible to investigate the archaeological histories of teosinte use pending the recovery of appropriate samples
Arterial oxygen content is precisely maintained by graded erythrocytotic responses in settings of high/normal serum iron levels, and predicts exercise capacity: an observational study of hypoxaemic patients with pulmonary arteriovenous malformations.
Oxygen, haemoglobin and cardiac output are integrated components of oxygen transport: each gram of haemoglobin transports 1.34 mls of oxygen in the blood. Low arterial partial pressure of oxygen (PaO2), and haemoglobin saturation (SaO2), are the indices used in clinical assessments, and usually result from low inspired oxygen concentrations, or alveolar/airways disease. Our objective was to examine low blood oxygen/haemoglobin relationships in chronically compensated states without concurrent hypoxic pulmonary vasoreactivity.165 consecutive unselected patients with pulmonary arteriovenous malformations were studied, in 98 cases, pre/post embolisation treatment. 159 (96%) had hereditary haemorrhagic telangiectasia. Arterial oxygen content was calculated by SaO2 x haemoglobin x 1.34/100.There was wide variation in SaO2 on air (78.5-99, median 95)% but due to secondary erythrocytosis and resultant polycythaemia, SaO2 explained only 0.1% of the variance in arterial oxygen content per unit blood volume. Secondary erythrocytosis was achievable with low iron stores, but only if serum iron was high-normal: Low serum iron levels were associated with reduced haemoglobin per erythrocyte, and overall arterial oxygen content was lower in iron deficient patients (median 16.0 [IQR 14.9, 17.4]mls/dL compared to 18.8 [IQR 17.4, 20.1]mls/dL, p<0.0001). Exercise tolerance appeared unrelated to SaO2 but was significantly worse in patients with lower oxygen content (p<0.0001). A pre-defined athletic group had higher Hb:SaO2 and serum iron:ferritin ratios than non-athletes with normal exercise capacity. PAVM embolisation increased SaO2, but arterial oxygen content was precisely restored by a subsequent fall in haemoglobin: 86 (87.8%) patients reported no change in exercise tolerance at post-embolisation follow-up.Haemoglobin and oxygen measurements in isolation do not indicate the more physiologically relevant oxygen content per unit blood volume. This can be maintained for SaO2 ≥78.5%, and resets to the same arterial oxygen content after correction of hypoxaemia. Serum iron concentrations, not ferritin, seem to predict more successful polycythaemic responses
Locomotor hyperactivity in 14-3-3Zeta KO mice is associated with dopamine transporter dysfunction
Dopamine (DA) neurotransmission requires a complex series of enzymatic reactions that are tightly linked to catecholamine exocytosis and receptor interactions on pre- and postsynaptic neurons. Regulation of dopaminergic signalling is primarily achieved through reuptake of extracellular DA by the DA transporter (DAT) on presynaptic neurons. Aberrant regulation of DA signalling, and in particular hyperactivation, has been proposed as a key insult in the presentation of schizophrenia and related neuropsychiatric disorders. We recently identified 14-3-3ζ as an essential component of neurodevelopment and a central risk factor in the schizophrenia protein interaction network. Our analysis of 14-3-3ζ-deficient mice now shows that baseline hyperactivity of knockout (KO) mice is rescued by the antipsychotic drug clozapine. 14-3-3ζ KO mice displayed enhanced locomotor hyperactivity induced by the DA releaser amphetamine. Consistent with 14-3-3ζ having a role in DA signalling, we found increased levels of DA in the striatum of 14-3-3ζ KO mice. Although 14-3-3ζ is proposed to modulate activity of the rate-limiting DA biosynthesis enzyme, tyrosine hydroxylase (TH), we were unable to identify any differences in total TH levels, TH localization or TH activation in 14-3-3ζ KO mice. Rather, our analysis identified significantly reduced levels of DAT in the absence of notable differences in RNA or protein levels of DA receptors D1–D5. Providing insight into the mechanisms by which 14-3-3ζ controls DAT stability, we found a physical association between 14-3-3ζ and DAT by co-immunoprecipitation. Taken together, our results identify a novel role for 14-3-3ζ in DA neurotransmission and provide support to the hyperdopaminergic basis of pathologies associated with schizophrenia and related disorders.H Ramshaw, X Xu, EJ Jaehne, P McCarthy, Z Greenberg, E Saleh, B McClure, J Woodcock, S Kabbara, S Wiszniak, Ting-Yi Wang, C Parish, M van den Buuse, BT Baune, A Lopez and Q Schwar
Immunotherapy for neuroblastoma using syngeneic fibroblasts transfected with IL-2 and IL-12
Cytokine-modified tumour cells have been used in clinical trials for immunotherapy of neuroblastoma, but primary tumour cells from surgical biopsies are difficult to culture. Autologous fibroblasts, however, are straightforward to manipulate in culture and easy to transfect using nonviral or viral vectors. Here we have compared the antitumour effect of fibroblasts and tumour cells transfected ex vivo to coexpress interleukin-2 (IL-2) and IL-12 in a syngeneic mouse model of neuroblastoma. Coinjection of cytokine-modified fibroblasts with Neuro-2A tumour cells abolished their in vivo tumorigenicity. Treatment of established tumours with three intratumoral doses of transfected fibroblasts showed a significant therapeutic effect with reduced growth or complete eradication of tumours in 90% of mice, associated with extensive leukocyte infiltration. Splenocytes recovered from vaccinated mice showed enhanced IL-2 production following Neuro-2A coculture, and increased cytotoxicity against Neuro-2A targets compared with controls. Furthermore, 100% of the tumour-free mice exhibited immune memory against tumour cells when rechallenged three months later. The potency of transfected fibroblasts was equivalent to that of tumour cells in all experiments. We conclude that syngeneic fibroblasts cotransfected with IL-2 and IL-12 mediate therapeutic effects against established disease, and are capable of generating immunological memory. Furthermore, as they are easier to recover and manipulate than autologous tumour cells, fibroblasts provide an attractive alternative immunotherapeutic strategy for the treatment of neuroblastoma
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