1,487 research outputs found

    Leisure Time Use, Meaning of Life, and Psychological Distress: Comparing Canadian and Korean Older Adults

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    Older adults’ day-to-day leisure time activities both reflect and stimulate physical, cognitive, and social capacities that contribute to their quality of life. To better understand how leisure activity choices and possible impacts vary across two cultures, this questionnaire-based study compared leisure time use, perceived meaning of life, and psychological distress for 617 older adults in Canada (n=298) and the Republic of Korea (Korea) (n=319). Compared to Koreans, Canadian respondents spent more time overall in leisure activities and devoted a higher percentage of their total leisure time to active, rather than passive, activities. They spent significantly more of their time on cognitively active activities, while Koreans preferred socially and physically active ones and scored significantly higher on both meaning of life and psychological distress. Both groups spent more of their time watching television than on any other single reported activity. Age group, retirement status, health, education, and income varied across the two countries and were significantly associated with aspects of leisure time use for each group. The results identify areas for improvement if Canadian and Korean older adults’ leisure time use is to effectively support their aging well

    Efficient and Scalable 4-th order Match Propagation

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    International audienceWe propose a robust method to match image feature points taking into account geometric consistency. It is a careful adaptation of the match propagation principle to 4th-order geometric constraints (match quadruple consistency). With our method, a set of matches is explained by a network of locally-similar affinities. This approach is useful when simple descriptor-based matching strategies fail, in particular for highly ambiguous data, e.g., with repetitive patterns or where texture is lacking. As it scales easily to hundreds of thousands of matches, it is also useful when denser point distributions are sought, e.g., for high-precision rigid model estimation. Experiments show that our method is competitive (efficient, scalable, accurate, robust) against state-of-the-art methods in deformable object matching, camera calibration and pattern detection

    High-Level Bottom-Up Cues for Top-Down Parsing of Facade Images

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    International audienceWe address the problem of parsing images of building facades. The goal is to segment images, assigning to the resulting regions semantic labels that correspond to the basic architectural elements. We assume a top-down parsing framework is developed beforehand, based on a 2D shape grammar that encodes a prior knowledge on the possible composition of facades. The algorithm explores the space of feasible solutions by generating the possible configurations of the facade and comparing it to the input data by means of a local, pixel- or patch-based classifier. We propose new bottom-up cues for the algorithm, both for evaluation of a candidate parse and for guiding the exploration of the space of feasible solutions. The method that we propose benefits from detection-based information and leverages on the similar appearance of elements that repeat in a given facade. Experiments performed on standard datasets show that this use of more discriminative bottom-up cues improves the convergence in comparison to state-of-the-art algorithms, and gives better results in terms of precision and recall, as well as computation time and deviation

    Mercury speciation, transformation, and transportation in soils, atmospheric flux, and implications for risk management : a critical review

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    Mercury (Hg) is a potentially harmful trace element in the environment and one of the World Health Organization's foremost chemicals of concern. The threat posed by Hg contaminated soils to humans is pervasive, with an estimated 86 Gg of anthropogenic Hg pollution accumulated in surface soils worldwide. This review critically examines both recent advances and remaining knowledge gaps with respect to cycling of mercury in the soil environment, to aid the assessment and management of risks caused by Hg contamination. Included in this review are factors aïŹ€ecting Hg release from soil to the atmosphere, including how rainfall events drive gaseous elemental mercury (GEM) ïŹ‚ux from soils of low Hg content, and how ambient conditions such as atmospheric O3 concentration play a signiïŹcant role. Mercury contaminated soils constitute complex systems where many interdependent factors, including the amount and composition of soil organic matter and clays, oxidized minerals (e.g. Fe oxides), reduced elements (e.g. S2−), as well as soil pH and redox conditions aïŹ€ect Hg forms and transformation. Speciation inïŹ‚uences the extent and rate of Hg subsurface transportation, which has often been assumed insigniïŹcant. Nano-sized Hg particles as well as soluble Hg complexes play important roles in soil Hg mobility, availability, and methylation. Finally, implications for human health and suggested research directions are put forward, where there is signiïŹcant potential to improve remedial actions by accounting for Hg speciation and transportation factors

    Increased Na+/H+ antiport activity in the renal brush border membrane of SHR

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    Increased Na+/H+ antiport activity in the renal brush border membrane of SHR. Defect in renal salt excretion may play an important role in the pathogenesis of hypertension. We examined sodium (Na+) uptake by brush border membrane (BBM) vesicles of young (6 week old) spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) of the same age. SHR had lower urinary Na+ excretion (223.1 ± 9.3 vs. 266.3 ± 3.7 ”Eq/day/lOO g, N = 8, P < 0.01) and higher systolic blood pressure (98.9 ± 1.2 vs. 82.9 ± 1.8mm Hg, N = 8, P < 0.01) than WKY. BBM vesicle Na+ uptake, measured by rapid filtration technique, was higher in SHR when compared to WKY (1.44 ± 0.03 vs. 1.01 ± 0.06 nmol/mg/5 sec, N = 4, N < 0.01). This increase in Na+ influx was apparent only in the present of an outward-directed proton (H+) gradient and was abolished by 1mM amiloride. BBM permeability to H+ as assessed by acridine orange quenching was not different between SHR and WKY. Kinetic analyses of the amiloride-sensitive BBM Na+ uptake revealed a higher Vmax (2.13 ± 0.27 vs. 0.70 ± 0.30 nmol/mg/5 sec, N = 4, P < 0.01) and a higher km for Na+ (3.55 ± 0.32 vs. 1.23 ± 0.14mM, N = 4, P < 0.05) in SHR. These findings thus demonstrate an intrinsic derangement in BBM Na+ transport in young SHR which is characterized by increased Na+/H+ antiport activity. This alteration in antiport activity is not attributable to changes in membrane permeability to H+, and is characterized by higher Vmax and km. Similar reports of increased Na+/H+ antiport activity in other tissues of SHR suggest that a generalized membrane transport disorder may exist in this model of genetic hypertension

    Human Periodontal Fibroblast Response to Enamel Matrix Derivative, Amelogenin, and Platelet‐Derived Growth Factor‐BB

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142271/1/jper1242.pd

    Remediation of mercury contaminated soil, water, and air : a review of emerging materials and innovative technologies

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    Mercury contamination in soil, water and air is associated with potential toxicity to humans and ecosystems. Industrial activities such as coal combustion have led to increased mercury (Hg) concentrations in different environmental media. This review critically evaluates recent developments in technological approaches for the remediation of Hg contaminated soil, water and air, with a focus on emerging materials and innovative technologies. Extensive research on various nanomaterials, such as carbon nanotubes (CNTs), nanosheets and magnetic nanocomposites, for mercury removal are investigated. This paper also examines other emerging materials and their characteristics, including graphene, biochar, metal organic frameworks (MOFs), covalent organic frameworks (COFs), layered double hydroxides (LDHs) as well as other materials such as clay minerals and manganese oxides. Based on approaches including adsorption/desorption, oxidation/reduction and stabilization/containment, the performances of innovative technologies with the aid of these materials were examined. In addition, technologies involving organisms, such as phytoremediation, algae-based mercury removal, microbial reduction and constructed wetlands, were also reviewed, and the role of organisms, especially microorganisms, in these techniques are illustrated

    Preclinical assessments of the MEK inhibitor PD-0325901 in a mouse model of neurofibromatosis type 1.

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    Background: Neurofibromatosis type 1 (NF1) is a genetic disorder that predisposes affected individuals to formation of benign neurofibromas, peripheral nerve tumors that can be associated with significant morbidity. Loss of the NF1 Ras-GAP protein causes increased Ras-GTP, and we previously found that inhibiting MEK signaling downstream of Ras can shrink established neurofibromas in a genetically engineered murine model. Procedures: We studied effects of MEK inhibition using 1.5 mg/kg/day PD-0325901 prior to neurofibroma onset in the Nf1 flox/flox;Dhh-Cre mouse model. We also treated mice with established tumors at 0.5 and 1.5 mg/kg/day dosees of PD-0325901. We monitored tumor volumes using MRI and volumetric measurements, and measured pharmacokinetic and pharmacodynamic endpoints. Results: Early administration significantly delayed neurofibroma development as compared to vehicle controls. When treatment was discontinued neurofibromas grew, but no rebound effect was observed and neurofibromas remained significantly smaller than controls. Low dose treatment of mice with PD-0325901 resulted in neurofibroma shrinkage equivalent to that observed at higher doses. Tumor cell proliferation decreased, although less than at higher doses with drug. Tumor blood vessels per area correlated with tumor shrinkage. Conclusions: Neurofibroma development was not prevented by MEK inhibition, beginning at 1 month of age, but tumor size was controlled by early treatment. Moreover, treatment with PD-0325901 at very low doses may shrink neurofibromas while minimizing toxicity. These studies highlight how genetically engineered mouse models can guide clinical trial design

    Field-induced spin density wave in (TMTSF)2_2NO3_3

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    Interlayer magnetoresistance of the Bechgaard salt (TMTSF)2_2NO3_3 is investigated up to 50 teslas under pressures of a few kilobars. This compound, the Fermi surface of which is quasi two-dimensional at low temperature, is a semi metal under pressure. Nevertheless, a field-induced spin density wave is evidenced at 8.5 kbar above ∌\sim 20 T. This state is characterized by a drastically different spectrum of the quantum oscillations compared to the low pressure spin density wave state.Comment: to be published in Phys. Rev. B 71 (2005
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