1,775 research outputs found
WP 17 - Working women's choices for domestic help
Household services are increasing. Which households consume these services, in particular domestic help? This article tests whether time and financial resources influence the use of domestic help, performing logistic regression analyses with the WWIQ-2000/01-data (N=10,969), addressing working women in the Netherlands. The use of paid domestic cleaning services is highly dependent upon a woman’s working hours, supervisory position and hourly wages. It is to a minor extent dependent upon children and partner. Age and high education have a substantial impact. The factors influencing paid domestic help predict neither occasional and unpaid help, nor the number of hours of paid domestic help.
Relating Agulhas leakage to the Agulhas Current retroflection location
The relation between the Agulhas Current
retroflection location and the magnitude of Agulhas leakage,
the transport of water from the Indian to the Atlantic Ocean,
is investigated in a high-resolution numerical ocean model.
Sudden eastward retreats of the Agulhas Current retroflection
loop are linearly related to the shedding of Agulhas rings,
where larger retreats generate larger rings. Using numerical
Lagrangian floats a 37 year time series of the magnitude of
Agulhas leakage in the model is constructed. The time series
exhibits large amounts of variability, both on weekly and annual
time scales. A linear relation is found between the magnitude
of Agulhas leakage and the location of the Agulhas
Current retroflection, both binned to three month averages.
In the relation, a more westward location of the Agulhas Current
retroflection corresponds to an increased transport from
the Indian Ocean to the Atlantic Ocean. When this relation
is used in a linear regression and applied to almost 20 years
of altimetry data, it yields a best estimate of the mean magnitude
of Agulhas leakage of 13.2 Sv. The early retroflection
of 2000, when Agulhas leakage was probably halved, can be
identified using the regression
Protein transfer to membranes upon shape deformation
Red blood cells, milk fat droplets, or liposomes all have interfaces consisting of lipid membranes. These particles show significant shape deformations as a result of flow. Here we show that these shape deformations can induce adsorption of proteins to the membrane. Red blood cell deformability is an important factor in several diseases involving obstructions of the microcirculatory system, and deformation induced protein adsorption will alter the rigidity of their membranes. Deformation induced protein transfer will also affect adsorption of cells onto implant surfaces, and the performance of liposome based controlled release systems. Quantitative models describing this phenomenon in biomaterials do not exist. Using a simple quantitative model, we provide new insight in this phenomenon. We present data that show convincingly that for cells or droplets with diameters upwards of a few micrometers, shape deformations induce adsorption of proteins at their interface even at moderate flow rate
Spreading Dynamics of Polymer Nanodroplets
The spreading of polymer droplets is studied using molecular dynamics
simulations. To study the dynamics of both the precursor foot and the bulk
droplet, large drops of ~200,000 monomers are simulated using a bead-spring
model for polymers of chain length 10, 20, and 40 monomers per chain. We
compare spreading on flat and atomistic surfaces, chain length effects, and
different applications of the Langevin and dissipative particle dynamics
thermostats. We find diffusive behavior for the precursor foot and good
agreement with the molecular kinetic model of droplet spreading using both flat
and atomistic surfaces. Despite the large system size and long simulation time
relative to previous simulations, we find no evidence of hydrodynamic behavior
in the spreading droplet.Comment: Physical Review E 11 pages 10 figure
Mesoscale perturbations control inter-ocean exchange south of Africa
The quantification of inter-ocean leakage from the South Indian to the South Atlantic Ocean is an important measure for the role of the Agulhas system in the global thermohaline circulation. To explore the specific role of mesoscale variability (such as Agulhas rings and Mozambique eddies) in this process a high-resolution model (based on NEMO-ORCA) for the Agulhas region has been set up. It is nested into a global coarse-resolution model. The high-resolution nest captures all salient features of the greater Agulhas region, including the upstream perturbations of the Agulhas Current and Natal Pulses along the African coast. A comparison of the inter-ocean exchange in the high-resolution nest with its coarse resolution counterpart reveals that the latter significantly over-estimates the amount of water flowing into the Atlantic Ocean, demonstrating the need to explicitly simulate the mesoscale features. A sensitivity experiment that excludes the upstream perturbations revealed no difference in the amount of inter-ocean exchange. However, the realistic representation of Agulhas rings and their drift path into the South Atlantic depends on the simulation of those upstream perturbations
Codebook and explanatory note on the EurOccupations dataset about the job content of 150 occupations
Blood pressure variability and cardiovascular risk in the PROspective study of pravastatin in the elderly at risk (PROSPER)
Variability in blood pressure predicts cardiovascular disease in young- and middle-aged subjects, but relevant data for older individuals are sparse. We analysed data from the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) study of 5804 participants aged 70–82 years with a history of, or risk factors for cardiovascular disease. Visit-to-visit variability in blood pressure (standard deviation) was determined using a minimum of five measurements over 1 year; an inception cohort of 4819 subjects had subsequent in-trial 3 years follow-up; longer-term follow-up (mean 7.1 years) was available for 1808 subjects. Higher systolic blood pressure variability independently predicted long-term follow-up vascular and total mortality (hazard ratio per 5 mmHg increase in standard deviation of systolic blood pressure = 1.2, 95% confidence interval 1.1–1.4; hazard ratio 1.1, 95% confidence interval 1.1–1.2, respectively). Variability in diastolic blood pressure associated with increased risk for coronary events (hazard ratio 1.5, 95% confidence interval 1.2–1.8 for each 5 mmHg increase), heart failure hospitalisation (hazard ratio 1.4, 95% confidence interval 1.1–1.8) and vascular (hazard ratio 1.4, 95% confidence interval 1.1–1.7) and total mortality (hazard ratio 1.3, 95% confidence interval 1.1–1.5), all in long-term follow-up. Pulse pressure variability was associated with increased stroke risk (hazard ratio 1.2, 95% confidence interval 1.0–1.4 for each 5 mmHg increase), vascular mortality (hazard ratio 1.2, 95% confidence interval 1.0–1.3) and total mortality (hazard ratio 1.1, 95% confidence interval 1.0–1.2), all in long-term follow-up. All associations were independent of respective mean blood pressure levels, age, gender, in-trial treatment group (pravastatin or placebo) and prior vascular disease and cardiovascular disease risk factors. Our observations suggest variability in diastolic blood pressure is more strongly associated with vascular or total mortality than is systolic pressure variability in older high-risk subjects
Річард Смоллі і знамениті «десять вересневих днів»
У вересні цього року виповнюється 27 років, як було відкрито фулерен — нову сфероподібну форму вуглецю. Ця подія буквально приголомшила вчених, які на той час вважали, що про елементарний вуглець їм відомо практично все. Історія відкриття цієї речовини досить незвичайна. Ще в 1971 р. можливість існування молекули фулерену була передбачена японським ученим Е. Осавою (E. Osawa), за два роки радянські хіміки-теоретики Д.А. Бочвар і О.Г. Гальперн квантово-хімічними розрахунками підтвердили стабільність молекули С60, і лише у 1985 р. Р. Смоллі, Р. Керл та Г. Крото експериментально отримали кластери із 60 атомів вуглецю в стійкій формі, яку вони пояснили структурою молекули у вигляді футбольного м’яча. Натхненнику цього відкриття, видатному вченому, нобелівському лауреату, активному популяризатору нанотехнологій Річарду Смоллі присвячено цей матеріал.В сентябре этого года исполняется 27 лет с момента открытия фуллерена — новой сферообразной формы углерода. Это событие буквально потрясло ученых, которые в то время считали, что об элементарном углероде им известно практически все. История открытия этого вещества довольно необычна. Еще в 1971 г. возможность су ществования молекулы фуллерена была предсказана японским ученым Е. Осавой (E. Osawa), через два года советские химики-теоретики Д.А. Бочвар и Е.Г. Гальперн с помощью квантово-химических расчетов подтвердили стабильность молекулы С60, и только в 1985 г. Р. Смолли, Р. Керл и Г. Крото экспериментально получили кластеры из 60 атомов углерода в устойчивой форме, которую они объяснили структурой молекулы в виде футбольного мяча. Вдохновителю этого открытия, выдающемуся ученому, нобелевскому лауреату, активному популяризатору нанотехнологий Ричарду Смолли посвящен этот материал.27 years since the discovery of fullerene, the new form of carbon, is observed in September of this year. This event has literally shocked scientists, who believed at that time that they know almost everything about the elementary carbon. History of this discovery is rather unusual. Long ago, in 1971 the possibility of the existence of a fullerene molecule was predicted by an young Japanese scientist E. Osawa. Then two Soviet chemists and theorists D.A. Bochvar and E.G. Hal pern confirm the stability of the C60 molecule using quantum chemical calculations, and in 1985 at last R. Smalley, R. Curl and H. Kroto experimentally obtained clusters of 60 carbon atoms in a sustainable form. They explained the structure of this molecule as the structure of a soccer ball. This material is devoted to the inspirer of this discovery, an outstanding scientist, Nobel laureate, active popularizer of nanotechnology — Richard Smalley
HDAC-mediated control of ERK- and PI3K-dependent TGF-β-induced extracellular matrix-regulating genes
Histone deacetylases (HDACs) regulate the acetylation of histones in the control of gene expression. Many non-histone proteins are also targeted for acetylation, including TGF-ß signalling pathway components such as Smad2, Smad3 and Smad7. Our studies in mouse C3H10T1/2 fibroblasts suggested that a number of TGF-ß-induced genes that regulate matrix turnover are selectively regulated by HDACs. Blockade of HDAC activity with trichostatin A (TSA) abrogated the induction of a disintegrin and metalloproteinase 12 (Adam12) and tissue inhibitor of metalloproteinases-1 (Timp-1) genes by TGF-ß, whereas plasminogen activator inhibitor-1 (Pai-1) expression was unaffected. Analysis of the activation of cell signalling pathways demonstrated that TGF-ß induced robust ERK and PI3K activation with delayed kinetics compared to the phosphorylation of Smads. The TGF-ß induction of Adam12 and Timp-1 was dependent on such non-Smad signalling pathways and, importantly, HDAC inhibitors completely blocked their activation without affecting Smad signalling. Analysis of TGF-ß-induced Adam12 and Timp-1 expression and ERK/PI3K signalling in the presence of semi-selective HDAC inhibitors valproic acid, MS-275 and apicidin implicated a role for class I HDACs. Furthermore, depletion of HDAC3 by RNA interference significantly down-regulated TGF-ß-induced Adam12 and Timp-1 expression without modulating Pai-1 expression. Correlating with the effect of HDAC inhibitors, depletion of HDAC3 also blocked the activation of ERK and PI3K by TGF-ß. Collectively, these data confirm that HDACs, and in particular HDAC3, are required for activation of the ERK and PI3K signalling pathways by TGF-ß and for the subsequent gene induction dependent on these signalling pathways
The effect of unfiltered coffee on potential biomarkers for colonic cancer risk in healthy volunteers: a randomized trial
Background: Epidemiologic studies suggest that coffee use might protect against colorectal cancer. Inconsistencies as to the effect of coffee use and colorectal cancer between epidemiologic studies might be related to the type of coffee brew. Objective: We studied the effect of unfiltered coffee consumption on putative biomarkers for colonic cancer risk. Design: A total of 64 healthy volunteers (31 men and 33 women), with a mean age of 43 ± 11 years were randomly assigned to two groups in a crossover design, with two intervention periods of 2 weeks separated by a washout period of 8 weeks. Treatments were 1 L of cafetiere (French press) coffee daily or no coffee. At the end of each intervention period, fasting blood samples, colorectal biopsies and 48 h faeces were collected. Results: No effect of coffee on colorectal cell proliferation, assayed by estimating the Proliferating Cell Nuclear Antigen labelling index, was seen. Additionally, no effects were seen on the concentrations of faecal soluble bile acids and colorectal mucosal glutathione S-transferase activity. However, unfiltered coffee significantly increased the glutathione content in the colorectal mucosa by 8% and in plasma by 15%. Other aminothiols in plasma also increased on coffee. Conclusion: Unfiltered coffee does not influence the colorectal mucosal proliferation rate, but might increase the detoxification capacity and anti-mutagenic properties in the colorectal mucosa through an increase in glutathione concentration. Whether this effect indeed contributes to a lower colon cancer risk remains to be established
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