2,089 research outputs found
Correlation between birth weight and placental weight in healthy and diabetic puerperae
Abstract Objective The birth weight/placental weight ratio has an important predictive value for perinatal mortality and morbidity and for cardiovascular diseases in adult life. In this study, we compared the birth weight/placental weight (BW/PW) ratio and the correlation between the two parameters in diabetic women with that observed in healthy women. Materials and Methods A total of 347 consecutive newborn infants from healthy puerperae, 164 newborns from puerperae with gestational diabetes, 148 newborns from puerperae with preexisting type 1 diabetes, and 40 newborns from puerperae with preexisting type 2 diabetes have been studied from the White population of Rome. The research project was approved by the Institutional Review Board and informed written consent was obtained from the participating mothers. Results The BW/PW ratio is higher, and the correlation between the two parameters is lower in all classes of diabetes as compared to healthy puerperae. A remarkably low correlation is observed in preexisting diabetes pointing to a dissociation of fetal growth from placental growth. Discussion In diabetic pregnancy the BW/PW ratio is higher, and the correlation between birth weight and placental weight is lower in all classes of diabetic as compared to healthy puerperae pointing to a relative dissociation between the two parameters. It has been suggested that the increase of glycemic levels in diabetic pregnancy predisposes to important diseases in adult life. The dissociation of BW from PW in infants of diabetic pregnancy could be a predictor of the risk for such diseases of adult life
Recommended from our members
Dynamical control of the mesosphere by orographic and non-orographic gravity wave drag during the extended northern winters of 2006 and 2009
A version of the Canadian Middle Atmosphere Model (CMAM) that is nudged toward reanalysis data up to 1 hPa is used to examine the impacts of parameterized orographic and non-orographic gravity wave drag (OGWD and NGWD) on the zonal-mean circulation of the mesosphere during the extended northern winters of 2006 and 2009 when there were two large stratospheric sudden warmings. The simulations are compared to Aura Microwave Limb Sounder (MLS) observations of mesospheric temperature, carbon monoxide (CO) and derived zonal winds. The control simulation, which uses both OGWD and NGWD, is shown to be in good agreement with MLS. The impacts of OGWD and NGWD are assessed using simulations in which those sources of wave drag are removed. In the absence of OGWD the mesospheric zonal winds in the months preceding the warmings are too strong, causing increased mesospheric NGWD, which drives excessive downwelling, resulting in overly large lower mesospheric values of CO prior to the warming. NGWD is found to be most important following the warmings when the underlying westerlies are too weak to allow much vertical propagation of the orographic gravity waves to the mesosphere. NGWD is primarily responsible for driving the circulation that results in the descent of CO from the thermosphere following the warmings. Zonal mean mesospheric winds and temperatures in all simulations are shown to be strongly constrained by (i.e. slaved to) the stratosphere. Finally, it is demonstrated that the responses to OGWD and NGWD are non-additive due to their dependence and influence on the background winds and temperatures
The effect of dietary fat intake on hepatic gene expression in LG/J AND SM/J mice
Background
The liver plays a major role in regulating metabolic homeostasis and is vital for nutrient metabolism. Identifying the genetic factors regulating these processes could lead to a greater understanding of how liver function responds to a high-fat diet and how that response may influence susceptibilities to obesity and metabolic syndrome. In this study we examine differences in hepatic gene expression between the LG/J and SM/J inbred mouse strains and how gene expression in these strains is affected by high-fat diet. LG/J and SM/J are known to differ in their responses to a high-fat diet for a variety of obesity- and diabetes-related traits, with the SM/J strain exhibiting a stronger phenotypic response to diet. Results
Dietary intake had a significant effect on gene expression in both inbred lines. Genes up-regulated by a high-fat diet were involved in biological processes such as lipid and carbohydrate metabolism; protein and amino acid metabolic processes were down regulated on a high-fat diet. A total of 259 unique transcripts exhibited a significant diet-by-strain interaction. These genes tended to be associated with immune function. In addition, genes involved in biochemical processes related to non-alcoholic fatty liver disease (NAFLD) manifested different responses to diet between the two strains. For most of these genes, SM/J had a stronger response to the high-fat diet than LG/J. Conclusions
These data show that dietary fat impacts gene expression levels in SM/J relative to LG/J, with SM/J exhibiting a stronger response. This supports previous data showing that SM/J has a stronger phenotypic response to high-fat diet. Based upon these findings, we suggest that SM/J and its cross with the LG/J strain provide a good model for examining non-alcoholic fatty liver disease and its role in metabolic syndrome
Response of a catalytic reaction to periodic variation of the CO pressure: Increased CO_2 production and dynamic phase transition
We present a kinetic Monte Carlo study of the dynamical response of a
Ziff-Gulari-Barshad model for CO oxidation with CO desorption to periodic
variation of the CO presure. We use a square-wave periodic pressure variation
with parameters that can be tuned to enhance the catalytic activity. We produce
evidence that, below a critical value of the desorption rate, the driven system
undergoes a dynamic phase transition between a CO_2 productive phase and a
nonproductive one at a critical value of the period of the pressure
oscillation. At the dynamic phase transition the period-averged CO_2 production
rate is significantly increased and can be used as a dynamic order parameter.
We perform a finite-size scaling analysis that indicates the existence of
power-law singularities for the order parameter and its fluctuations, yielding
estimated critical exponent ratios and . These exponent ratios, together with theoretical symmetry
arguments and numerical data for the fourth-order cumulant associated with the
transition, give reasonable support for the hypothesis that the observed
nonequilibrium dynamic phase transition is in the same universality class as
the two-dimensional equilibrium Ising model.Comment: 18 pages, 10 figures, accepted in Physical Review
Rheological and mechanical properties of acellular and cellladen methacrylated gellan gum hydrogels
Tissue engineered hydrogels hold great potential as nucleus pulposus substitutes (NP), as they promote intervertebral disc (IVD) regeneration and re-establish its original function. But, the key to their success in future clinical applications greatly depends on its ability to replicate the native 3D micro-environment and circumvent their limitation in terms of mechanical performance. In the present study, we investigated the rheological/mechanical properties of both ionic- (iGG-MA) and photo-crosslinked methacrylated gellan gum (phGG-MA) hydrogels. Steady shear analysis, injectability and confined compression stress-relaxation tests were carried out. The injectability of the reactive solutions employed for the preparation of iGG-MA and phGG-MA hydrogels was firstly studied, then the zero-strain compressive modulus and permeability of the acellular hydrogels were evaluated.In addition, human intervertebral disc (hIVD) cells encapsulated in both iGG-MA and phGG-MA hydrogels were cultured in vitro, and its mechanical properties also investigated under dynamic mechanical analysis at 37ºC and pH 7.4. After 21 d of culturing, hIVD cells were alive (Calcein AM) and the E’ of ionic-crosslinked hydrogels and photo-crosslinked was higher than that observed for acellular hydrogels. Our study suggests that methacrylated gellan gum hydrogels present promising mechanical and biological performance as hIVD cells were producing extracellular matrix
Genomic selection for slaughter age in pigs using the Cox frailty model.
The aim of this study was to compare genomic selection methodologies using a linear mixed model and the Cox survival model. We used data from an F2 population of pigs, in which the response variable was the time in days from birth to the culling of the animal and the covariates were 238 markers [237 single nucleotide polymorphism (SNP) plus the halothane gene]. The data were corrected for fixed effects, and the accuracy of the method was determined based on the correlation of the ranks of predicted genomic breeding values (GBVs) in both models with the corrected phenotypic values. The analysis was repeated with a subset of SNP markers with largest absolute effects. The results were in agreement with the GBV prediction and the estimation of marker effects for both models for uncensored data and for normality. However, when considering censored data, the Cox model with a normal random effect (S1) was more appropriate. Since there was no agreement between the linear mixed model and the imputed data (L2) for the prediction of genomic values and the estimation of marker effects, the model S1 was considered superior as it took into account the latent variable and the censored data. Marker selection increased correlations between the ranks of predicted GBVs by the linear and Cox frailty models and the corrected phenotypic values, and 120 markers were required to increase the predictive ability for the characteristic analyzed
Analysis and performance assessment of the use of ammonia-based nano additive for lean combustion
In recent years, considerable progress has been made in exploring new applications of fuel additives to reduce emissions. Reduction of total nitrogen oxide (NOx) emissions can be achieved by decreasing the flame temperature by using fuel emulsified with water and/or using ammonia-based nano additives such as urea. The use of water as part of the hydrocarbon fuel is also one of the prospective directions in the development of new types of fuel systems. For the preparation of emulsified fuel, it is desirable to achieve greater stability of the emulsified fuel with minimum expenditure of chemicals and energy, so that the emulsified fuel can be used for a longer period. The paper analyzed the influence of nano-dispersed urea particles, water, and surfactant (Span 80/ Tween 80) on the combustion stability and emission characteristics of aviation fuel. The experimental campaign was conducted on a test stand (a 300kW liquid vortex combustor of 300 kW) consisting of a cylindrical combustion chamber with four optical windows
and equipped with high-precision pressure sensors, thermocouples, and an exhaust gas analyzer for acquiring emissions. The experimental campaign was conducted at a constant fuel/air ratio (Φ). One of the main focus is related to the stability of the emulsion. Chemiluminescence imaging was performed to characterize the effects of the additive on flame emissions. In addition, a statistical and spectral analysis was performed using the pressure sensor for instability analysis. Exhaust gas analysis was performed both with the additive described above and without additive for a constant Φ condition. The analysis was performed for NOx, carbon monoxide (CO) and carbon dioxide (CO2) and oxygen (O 2)
Recommended from our members
Summary and synthesis of Changing Cold Regions Network (CCRN) research in the interior of western Canada - Part 2: Future change in cryosphere, vegetation, and hydrology
Global reanalyses from data assimilation systems are among the most widely used datasets in weather and climate studies, and potential vorticity (PV) from reanalyses is invaluable for many studies of dynamical and transport processes. We assess how consistently modern reanalyses represent potential vorticity (PV) among each other, focusing not only on PV but also on process-oriented dynamical diagnostics including equivalent latitude calculated from PV and PV-based tropopause and stratospheric polar vortex characterization.
In particular we assess the National Centers for Environmental Prediction Climate Forecast System Reanalysis/Climate Forecast System, version 2 (CFSR/CFSv2) reanalysis, the European Centre for Medium-Range Weather Forecasts Interim (ERA-Interim) reanalysis, the Japanese Meteorological Agency's 55-year (JRA-55) reanalysis, and the NASA Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2). Overall, PV from all reanalyses agrees well with the reanalysis ensemble mean, providing some confidence that all of these recent reanalyses are suitable for most studies using PV-based diagnostics. Specific diagnostics where some larger differences are seen include PV-based tropopause locations in regions that have strong tropopause gradients (such as around the subtropical jets) or are sparse in high-resolution data (such as over Antarctica), and the stratospheric polar vortices during fall vortex formation and (especially) spring vortex breakup; studies of sensitive situations or regions such as these should examine PV from multiple reanalyses.
</p
Consumo e digestibilidade aparente das frações fibrosas das silagens de quatro genótipos de milho.
O objetivo deste trabalho foi avaliar o consumo e digestibilidade aparente das frações fibrosas das silagens de quatro genótipos de milho com diferentes graus de vitreosidade e com perfil de aminoácidos modificado (SHS 4040, AG 1051, BRS 3060, QPM 129). Foram utilizados 20 carneiros adultos com média de peso de 48,67 kg, machos, castrados, caudectomizados e sem raça definida. O delineamento utilizado foi o inteiramente casualizado. Os dados obtidos foram submetidos à análise de variância e as médias comparadas pelo teste de Student Newman Keuls (SNK) ao nÃvel de 5% de probabilidade (P<0,05). Os consumos voluntários de FDN e FDA foram 33,10. 26,77. 34,53 e 26,53 g/UTM/dia e 17,83, 14,80, 18,90 e 14,83 g/UTM/dia para os genótipos SHS 4040, QPM 129, AG 1051, BRS 3060, respectivamente. Os consumos de hemicelulose e celulose foram 15,27, 11,97, 15,63 e 11,70 g/UTM/dia e 15,89, 11,87, 16,63 e 13,72 g/UTM/dia para os genótipos acima, respectivamente. As digestibilidades aparentes variaram para FDN de 38,61 a 62.41 %, para FDA de 43,11 a 64,44%, para hemicelulose de 33,06 a 59,94% e para celulose de 42,75 a 66,59% com os genótipos QPM 129 e AG 1051 respectivamente. Os resultados deste trabalho evidenciam que os genótipos AG 1051 e SHS 4040 foram estatisticamente superiores aos demais genótipos quanto a consumo e digestibilidade da FDN e hemicelulose. Todos genótipos apresentam bom potencial para utilização como silagem para ruminantes
- …