2,442 research outputs found
Structural relaxation in the hydrogen-bonding liquids N-methylacetamide and water studied by optical Kerr-effect spectroscopy
Structural relaxation in the peptide model N-methylacetamide (NMA) is studied
experimentally by ultrafast optical Kerr-effect spectroscopy over the
normal-liquid temperature range and compared to the relaxation measured in
water at room temperature. It is seen that in both hydrogen-bonding liquids,
beta relaxation is present and in each case it is found that this can be
described by the Cole-Cole function. For NMA in this temperature range, the
alpha and beta relaxations are each found to have an Arrhenius temperature
dependence with indistinguishable activation energies. It is known that the
variations on the Debye function, including the Cole-Cole function, are
unphysical, and we introduce two general modifications: one allows for the
initial rise of the function, determined by the librational frequencies, and
the second allows the function to be terminated in the alpha relaxation
Fauna vretenaca (Insecta, Odonata) područja Banovine
In all, 32 dragonfly species were recorded between August 2010 and September 2011 at 21 localities in the Banovina region of Croatia, almost half of the total number known in Croatia. The most abundant species was Platycnemis pennipes while the rarest was Coenagrion ornatum. Ten of the recorded species are at a certain level of conservation concern and thus it is important to protect their habitats in region.U razdoblju između kolovoza 2010. i rujna 2011. godine na 21 postaji na području Banovine utvrđene su 32 vrste vretenaca, gotovo polovina broja vrsta prisutnih u Hrvatskoj. Najčešća zabilježena vrsta je Platycnemis pennipes dok je najrjeđa Coenagrion ornatum. Među zabilježenim vrstama vretenaca, deset ih je pod određenim stupnjem zaštite zbog čega se ističe važnost očuvanja i zaštite njihovih staništa na području Banovine
Residence time distribution and hold-up in a cocurrent upflow packed bed reactor at elevated pressure
The residence time distribution in liquid phase was measured in a cocurrent upflow packed bed reactor for the system methanol-hydrogen at low Reynolds numbers and at elevated pressure. The plug flow with axial dispersion model was used to describe mixing in the system. The imperfect pulse method was used to measure the system response to a tracer pulse input. The parameters were calculated using the weighted moments method. The influence of the weighting factor was investigated. The experimental and theoretical outputs, as calculated by convolution, agreed very well. Different types of correlations were used for the Bodenstein number and liquid hold-up. From these correlations, the optimal one was selected for each parameter. A comparison was made between the ordinary moments and the weighted moments methods which led to the conclusion that the latter method is superior with respect to the accuracy of the estimated parameters and therefore strongly recommended
How can the European Union adapt to climate change? Bruegel Policy Contribution Issue n˚11/22 | June 2022.
Europe must increasingly deal with the harmful impacts of climate change, regardless of its success in reducing emissions. These impacts have significant cross-border effects and threaten to deepen existing divisions. Cooperation on adaptation, which is mostly seen as requiring local or regional efforts, may be useful, but the role of the European Union is ill-defined.
We give an overview of how climate change might change Europe and how it might affect people and the economy. We also discuss what sort of adaptation policies are being pursued at EU level and on what grounds. We argue that a stronger adaptation governance framework would benefit adaptation efforts.
We formulate three ideas to strengthen adaptation. First is a three-layered governance framework based on intensive cooperation to establish binding adaptation plans. Second is an EU-level insurance scheme against damages from climate change, with the size of national contributions tied to the achievement of self-chosen targets in adaptation plans. Our final suggestion is to increase ex-ante adaptation funding by targeting more spending under EU regional and agricultural policies specifically to adaptation in the most vulnerable regions
Physical activity and fat-free mass during growth and in later life
BACKGROUND: Physical activity may be a way to increase and maintain fat-free mass (FFM) in later life, similar to the prevention of fractures by increasing peak bone mass.
OBJECTIVES: A study is presented of the association between FFM and physical activity in relation to age.
METHODS: In a cross-sectional study, FFM was analyzed in relation to physical activity in a large participant group as compiled in the International Atomic Energy Agency Doubly Labeled Water database. The database included 2000 participants, age 3-96 y, with measurements of total energy expenditure (TEE) and resting energy expenditure (REE) to allow calculation of physical activity level (PAL = TEE/REE), and calculation of FFM from isotope dilution.
RESULTS: PAL was a main determinant of body composition at all ages. Models with age, fat mass (FM), and PAL explained 76% and 85% of the variation in FFM in females and males \u3c 18 y old, and 32% and 47% of the variation in FFM in females and males ≥ 18 y old, respectively. In participants \u3c 18 y old, mean FM-adjusted FFM was 1.7 kg (95% CI: 0.1, 3.2 kg) and 3.4 kg (95% CI: 1.0, 5.6 kg) higher in a very active participant with PAL = 2.0 than in a sedentary participant with PAL = 1.5, for females and males, respectively. At age 18 y, height and FM-adjusted FFM was 3.6 kg (95% CI: 2.8, 4.4 kg) and 4.4 kg (95% CI: 3.2, 5.7 kg) higher, and at age 80 y 0.7 kg (95% CI: -0.2, 1.7 kg) and 1.0 kg (95% CI: -0.1, 2.1 kg) higher, in a participant with PAL = 2.0 than in a participant with PAL = 1.5, for females and males, respectively.
CONCLUSIONS: If these associations are causal, they suggest physical activity is a major determinant of body composition as reflected in peak FFM, and that a physically active lifestyle can only partly protect against loss of FFM in aging adults
The Infrared Properties of Submillimeter Galaxies: Clues From Ultra-Deep 70 Micron Imaging
We present 70 micron properties of submillimeter galaxies (SMGs) in the Great
Observatories Origins Deep Survey (GOODS) North field. Out of thirty
submillimeter galaxies (S_850 > 2 mJy) in the central GOODS-N region, we find
two with secure 70 micron detections. These are the first 70 micron detections
of SMGs. One of the matched SMGs is at z ~ 0.5 and has S_70/S_850 and S_70/S_24
ratios consistent with a cool galaxy. The second SMG (z = 1.2) has
infrared-submm colors which indicate it is more actively forming stars. We
examine the average 70 micron properties of the SMGs by performing a stacking
analysis, which also allows us to estimate that S_850 > 2 mJy SMGs contribute 9
+- 3% of the 70 micron background light. The S_850/S_70 colors of the SMG
population as a whole is best fit by cool galaxies, and because of the
redshifting effects these constraints are mainly on the lower z sub-sample. We
fit Spectral Energy Distributions (SEDs) to the far-infrared data points of the
two detected SMGs and the average low redshift SMG (z_{median}= 1.4). We find
that the average low-z SMG has a cooler dust temperature than local
ultraluminous infrared galaxies (ULIRGs) of similar luminosity and an SED which
is best fit by scaled up versions of normal spiral galaxies. The average low-z
SMG is found to have a typical dust temperature T = 21 -- 33 K and infrared
luminosity L_{8-1000 micron} = 8.0 \times 10^11 L_sun. We estimate the AGN
contribution to the total infrared luminosity of low-z SMGs is less than 23%.Comment: Accepted by ApJ. 14 pages, 6 figures. Minor revisions 20th Dec 200
Substrate utilization and metabolic profile in response to overfeeding with a high-fat diet in South Asian and white men:a sedentary lifestyle study
Background For the same BMI, South Asians have a higher body fat percentage, a higher liver fat content and a more adverse metabolic profile than whites. South Asians may have a lower fat oxidation than whites, which could result in an unfavorable metabolic profile when exposed to increased high-fat foods consumption and decreased physical activity as in current modern lifestyle. Objective To determine substrate partitioning, liver fat accumulation and metabolic profile in South Asian and white men in response to overfeeding with high-fat diet under sedentary conditions in a respiration chamber. Design Ten South Asian men (BMI, 18-29 kg/m(2)) and 10 white men (BMI, 22-33 kg/m(2)), matched for body fat percentage, aged 20-40 year were included. A weight maintenance diet (30% fat, 55% carbohydrate, and 15% protein) was given for 3 days. Thereafter, a baseline measurement of liver fat content (1H-MRS) and blood parameters was performed. Subsequently, subjects were overfed (150% energy requirement) with a high-fat diet (60% fat, 25% carbohydrate, and 15% protein) over 3 consecutive days while staying in a respiration chamber mimicking a sedentary lifestyle. Energy expenditure and substrate use were measured for 3 x 24-h. Liver fat and blood parameters were measured again after the subjects left the chamber. Results The 24-h fat oxidation as a percentage of total energy expenditure did not differ between ethnicities (P = 0.30). Overfeeding increased liver fat content (P = 0.02), but the increase did not differ between ethnicities (P = 0.64). In South Asians, overfeeding tended to increase LDL-cholesterol (P = 0.08), tended to decrease glucose clearance (P = 0.06) and tended to elevate insulin response (P = 0.07) slightly more than whites. Conclusions Despite a similar substrate partitioning and similar accretion of liver fat, overfeeding with high-fat under sedentary conditions tended to have more adverse effects on the lipid profile and insulin sensitivity in South Asians.</p
Drought tolerance conferred to sugarcane by association with Gluconacetobacter diazotrophicus: a transcriptomic view of hormone pathways
Sugarcane interacts with particular types of beneficial nitrogen-fixing bacteria that provide fixed-nitrogen and plant growth hormones to host plants, promoting an increase in plant biomass. Other benefits, as enhanced tolerance to abiotic stresses have been reported to some diazotrophs. Here we aim to study the effects of the association between the diazotroph Gluconacetobacter diazotrophicus PAL5 and sugarcane cv. SP70-1143 during water depletion by characterizing differential transcriptome profiles of sugarcane. RNA-seq libraries were generated from roots and shoots of sugarcane plants free of endophytes that were inoculated with G. diazotrophicus and subjected to water depletion for 3 days. A sugarcane reference transcriptome was constructed and used for the identification of differentially expressed transcripts. The differential profile of non-inoculated SP70-1143 suggests that it responds to water deficit stress by the activation of drought-responsive markers and hormone pathways, as ABA and Ethylene. qRT-PCR revealed that root samples had higher levels of G. diazotrophicus 3 days after water deficit, compared to roots of inoculated plants watered normally. With prolonged drought only inoculated plants survived, indicating that SP70-1143 plants colonized with G. diazotrophicus become more tolerant to drought stress than non-inoculated plants. Strengthening this hypothesis, several gene expression responses to drought were inactivated or regulated in an opposite manner, especially in roots, when plants were colonized by the bacteria. The data suggests that colonized roots would not be suffering from stress in the same way as non-inoculated plants. On the other hand, shoots specifically activate ABA-dependent signaling genes, which could act as key elements in the drought resistance conferred by G. diazotrophicus to SP70-1143. This work reports for the first time the involvement of G. diazotrophicus in the promotion of drought-tolerance to sugarcane cv. SP70-1143, and it describes the initial molecular events that may trigger the increased drought tolerance in the host plant
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