Review of model sensor studies on Pd/SnO2(110) surfaces

Studies performed at the National Institute of Standards and Technology on the model gas sensor system, Pd/SnO2(110), are reviewed. Adsorption and interfacial effects play a primary role in the gas sensing process, as they do in catalysis. For this reason, researchers have used a variety of surface sensitive techniques in the research, including x ray and ultraviolet photoelectron spectroscopies (XPS and UPS), low energy electron diffraction (LEED), and ion scattering spectroscopy (ISS). By combining these complementary techniques with in situ gas response (conductance) measurements, researchers were able to correlate directly sensor activity with the composition and structure of the Pd/SnO2 interface. Although the intent of this work is to develop an understanding of gas sensing mechanisms, its relevance to Pt/SnO2 catalytic systems is obvious

Automata theoretic aspects of temporal behaviour and computability in logical neural networks

Imperial Users onl

Perceptions of an older patient on the role of the family doctor in health promotion : a qualitative case study

Introduction: Health promotion and disease prevention are important aspects of primary health care. However, limited data are available concerning the opinions of older patients towards the respective services offered by family doctors. The aim of the present study was to evaluate an older patient's perception of the role of the family doctor in promoting his health, and identify those components that are difficult to examine in quantitative research. Methods: A qualitative case study of an 80-year-old man using an in-depth interview was carried out. The interview transcript was analyzed thematically. Our patient was an 80-year-old university-educated man, with stable social and financial circumstances, living with his wife. He had retired early on grounds of ill health (tuberculosis) and had received a disability pension prior to formal retirement. At the time of the interview, his medical problems included mild prostatic hypertrophy, scoliosis and hypertension. He considered his health status to be satisfactory. He had changed family doctor five years prior to the interview, as he had been dissatisfied with the care provided. Results: We found that our patient expected the family doctor to be aware of, and to discuss, the following issues: physical activity, diet, management of stress and mental health, use of alcohol and tobacco, personal hygiene, health screening, use of medication, and social activity. At the same time, our patient perceived the doctor's role as supplementary to his own in terms of the appraisal and maintenance of his health. Conclusions: Our findings provide evidence of what is important in the promotion of health among older people

Combined SIRT3 and SIRT5 deletion is associated with inner retinal dysfunction in a mouse model of type 1 diabetes

Abstract Diabetic retinopathy (DR) is a major cause of blindness in working adults in the industrialized world. In addition to vision loss caused by macular edema and pathological angiogenesis, DR patients often exhibit neuronal dysfunction on electrophysiological testing, suggesting that there may be an independent neuronal phase of disease that precedes vascular disease. Given the tremendous metabolic requirements of the retina and photoreceptors in particular, we hypothesized that derangements in metabolic regulation may accelerate retinal dysfunction in diabetes. As such, we induced hyperglycemia with streptozotocin in mice with monoallelic Nampt deletion from rod photoreceptors, mice lacking SIRT3, and mice lacking SIRT5 and tested multiple components of retinal function with electroretinography. None of these mice exhibited accelerated retinal dysfunction after induction of hyperglycemia, consistent with normal-appearing retinal morphology in hyperglycemic Sirt3 −/− or Sirt5 −/− mice. However, mice lacking both SIRT3 and SIRT5 (Sirt3 −/− Sirt5 −/− mice) exhibited significant evidence of inner retinal dysfunction after induction of hyperglycemia compared to hyperglycemic littermate controls, although this dysfunction was not accompanied by gross morphological changes in the retina. These results suggest that SIRT3 and SIRT5 may be involved in regulating neuronal dysfunction in DR and provide a foundation for future studies investigating sirtuin-based therapies

Downward Wage Rigidities and Other Firms’ Responses to an Economic Slowdown: Evidence from a Survey of Colombian Firms

This paper uses a wage setting survey of 1,305 Colombian firms to explore the nature and sources of wage rigidities. This is the first study of a non-European emerging economy that uses evidence from a survey of firms to analyse this topic. The survey was carried out during the first half of 2009, when the Colombian economy was showing signs of a slowdown in economic activity and increasing unemployment. The sample is fully representative of the population under study. The results provide evidence of nominal and real downward wage rigidities in the country. The most important factor in not reducing base wages during an economic slowdown is to avoid the loss of more experienced and productive workers, which is related to the efficiency wage theory in its adverse selection version. In addition, ordered logit regressions were used to determine what factors are related to wage rigidities. The findings indicate that, in general, permanent contracts, workforce composition, labour intensity and the presence of collective agreements play an important role in explaining wage rigidities in the country.Wage rigidities, survey evidence, efficiency wages, Colombia, labour market, ordered logit. Classification JEL: C25, J30, J50

Wage Adjustment Practices and the Link between Price and Wages: Survey Evidence from Colombian Firms

The aim of this paper is to explore firms’ wage adjustment practices in the Colombian formal labor market; specifically, the timing and frequency of wage increases, as well as the link between wage and price changes. To this end, we use an ad hoc survey of 1,305 small, medium and large firms belonging to all economic sectors, except the public sector. The results show most of the firms adjust base wages annually, mainly during the first quarter, which suggests wage changes in Colombia are time-dependent. Also, wage increases were concentrated around observed inflation and none of the firms cut wages. Moreover, factors associated with the performance of firms and workers alike are the main determinants of wage adjustments. Regarding the link between wages and price changes, econometric results indicate this relationship is stronger in sectors where labor costs represent a higher share of total costs and in firms operating in sectors with higher labor productivity.Wage increases, labor market, survey evidence, logit models, Colombia. Classification JEL: D22, J30, C25.

Are wages rigid in Colombia?: Empirical evidence based on a sample of wages at the firm level

This paper uses Colombian data at the firm level for the period 1999 to 2006 to provide microeconomic evidence on the existence and extent of downward nominal wage rigidity. To conduct the analysis, we use a rich panel of firms for white and blue collar workers, consisting of 1517 firms for the former and 781 firms for the latter. The presence of wage rigidity is determined by means of three statistic techniques used in recent literature, such as the analysis of the histograms of the distribution of wage changes, the LSW statistic and the Kahn test. The results suggest the existence of downward nominal wage rigidities; it is worth mentioning that rigidity is higher for blue collar workers than white collar workers, since the increase in the wages of the blue workers is generally done by taking into account the change in the minimum wage, which is why a higher rigidity would be expected.Wage rigidity, Kahn test, LSW Statistic, Colombia. Classification JEL: J31, E24, C23

Toward predicting Dinophysis blooms off NW Iberia: a decade of events

Dinophysis acuminata and Dinophysis acuta are recurrent species off NW Iberia but their outbreaks occur under different conditions. A decade (2004-2013) of weekly data for each species at two sentinel stations located at the entrance of Rias de Aveiro-AV (NW Portugal, 40 degrees 38.6' N) and Pontevedra-PO (Galicia, Spain, 42 degrees 21.5' N), were used to investigate the regional synchronism and mesoscale differences related to species detection, bloom (>200 cells L-1) initiation and development. Results highlight the high interannual variability of bloom events and summarize the associated meteorological/oceanographic conditions. D. acuta blooms were observed in 2004-2008 and 2013, and the species highest maxima at AV occurred after the highest maxima of its prey Mesodinium, with a time-lag of 2-3 weeks. D. acuminate blooms were observed every year at both stations. The cell concentration time series shows that the blooms generally present a sequence starting in March with D. acuminata in PO and three weeks later in AV, followed by D. acuta that starts at AV and three months later in PO. Exceptionally, D. acuminate blooms occurred earlier at AV than PO, namely in high spring upwelling (2007) or river runoff (2010) years. A four-year gap (2009-2012) of D. acuta blooms occurred after an anomalous 2008 autumn with intense upwelling which is interpreted as the result of an equatorward displacement of the population core. Numerical model solutions are used to analyze monthly alongshore current anomalies and test transport hypotheses for selected events. The results show a strong interannual variability in the poleward/equatorward currents associated with changes in upwelling forcing winds, the advection of D. acute blooms from AV to PO and the possibility that D. acuminata blooms at AV might result from inocula advected southward from PO. However, the sensitivity of the results to vertical position of the lagrangian tracers call for more studies on species distribution at the various bloom stages. (C) 2015 Elsevier B.V. All rights reserved