Estuarine water quality and plankton community responses in the Pensacola Bay Estuary

EPA Science Inventory

Phytoplankton serve a centrally important role in estuaries forming the base of the food web. Thus factors that affect phytoplankton production and species composition cascades to higher trophic levels, ultimately affecting secondary production. Given their sensitivity to myriad ...

"It's Scary at First": Reentry Women in College Composition Classes.

ERIC Educational Resources Information Center

Greenwood, Claudia M.

1990-01-01

Examines internal and external factors which affect the way women reentering higher education learn and write. Finds several constant internal factors: sense of inferiority among peers; inability to concentrate; sense of guilt; feeling out of place among younger students; fatigue; and doubt. Finds that positive internal factors outweigh negative…

Predicting Recidivism with the Psychopathy Checklist: Are Factor Score Composites Really Necessary?

ERIC Educational Resources Information Center

Walters, Glenn D.; Wilson, Nick J.; Glover, Anthony J. J.

2011-01-01

In two previous studies on general and violent recidivism (Walters & Heilbrun, 2010; Walters, Knight, Grann, & Dahle, 2008), the summed composite antisocial facet of the Psychopathy Checklist displayed incremental validity relative to the other 3 facets (interpersonal, affective, lifestyle), whereas the other 3 facets generally failed to…

Strain intensity factor approach for predicting the strength of continuously reinforced metal matrix composites

NASA Technical Reports Server (NTRS)

Poe, Clarence C., Jr.

1989-01-01

A method was previously developed to predict the fracture toughness (stress intensity factor at failure) of composites in terms of the elastic constants and the tensile failing strain of the fibers. The method was applied to boron/aluminum composites made with various proportions of 0 deg and +/- 45 deg plies. Predicted values of fracture toughness were in gross error because widespread yielding of the aluminum matrix made the compliance very nonlinear. An alternate method was develolped to predict the strain intensity factor at failure rather than the stress intensity factor because the singular strain field was not affected by yielding as much as the stress field. Far-field strains at failure were calculated from the strain intensity factor, and then strengths were calculated from the far-field strains using uniaxial stress-strain curves. The predicted strengths were in good agreement with experimental values, even for the very nonlinear laminates that contained only +/- 45 deg plies. This approach should be valid for other metal matrix composites that have continuous fibers.

Variation in essential oil composition within individual leaves of sweet basil (Ocimum basilicum L.) is more affected by leaf position than by leaf age.

PubMed

Fischer, Ravit; Nitzan, Nadav; Chaimovitsh, David; Rubin, Baruch; Dudai, Nativ

2011-05-11

The aroma in sweet basil is a factor affecting the commercial value of the crop. In previous studies leaf age was considered to be a factor that influences the composition of essential oil (EO). In this study it was hypothesized that a single observation of the EO content in leaves from different positions on the main stem (young vs old) could predict the developmental changes in the plant during its life cycle. Plants harvested at week 16 demonstrated an exponential increase (R(2) = 0.92) in EO concentration in leaves on the main stem and lateral shoots, indicating higher EO concentrations in younger than in older leaves. Eugenol and methyleugenol predominated (28-77%) in the extract. Eugenol levels were higher in younger leaves (∼53%), and methyl-eugenol levels predominated in older leaves (∼68%). Linalool was lower in mature leaves than in younger leaves. This suggested that eugenol converted into methyleugenol and linalool decreased as leaf mature. However, in weekly monitored plants, the levels of these compounds in the EO had limited variation in the maturing leaf regardless of its position on the stem. This proposed that the EO composition in an individual leaf is mostly affected by the leaf position on the stem and not by its maturation process. Because leaf position is related to plant development, it is probable that the plant's physiological age at the time of leaf formation from the primordial tissue is the factor affecting the EO composition. It was concluded that interpretation of scientific observations should be carried out with caution and that hypotheses should be tested utilizing multifaceted approaches.

Reviews on factors affecting fatigue behavior of high-Mn steels

NASA Astrophysics Data System (ADS)

Kim, Sangshik; Jeong, Daeho; Sung, Hyokyung

2018-01-01

A variety of factors affect the fatigue behavior of high-Mn steels, which include both extrinsic (i.e., loading type, R ratio, specimen type, surface condition, temperature, and environment) and intrinsic (i.e., chemical composition, grain size, microstructure, stacking fault energy) factors. Very often, the influence of extrinsic factors on the fatigue behavior is even greater than that of intrinsic factors, misleading the interpretation of fatigue data. The metallurgical factors influence the initiation and propagation behaviors of fatigue by altering the characteristics of slip that is prerequisite for fatigue damage accumulation. It is however not easy to separate the effect of each factor since they affect the fatigue behavior of high-Mn steels in complex and synergistic way. In this review, the fatigue data of high-Mn steels are summarized and the factors complicating the interpretation are discussed.

A Pilot Project to Identify Sex Role Factors Affecting the Employment of Vocational Students in Selected Occupational Areas. Final Report, February 1, 1980-June 30, 1980.

ERIC Educational Resources Information Center

Wichowski, Chester P.; DuMond, Doreen C.

A pilot study was conducted to identify sex role factors which could affect the search for employment and the adjustment to employment for vocational graduates in selected occupational areas. Target employment areas were identified through a review of occupations with a disproportionate composition by one sex or the other. These included…

Ecological and Evolutionary Effects of Stickleback on Community Structure

PubMed Central

Des Roches, Simone; Shurin, Jonathan B.; Schluter, Dolph; Harmon, Luke J.

2013-01-01

Species’ ecology and evolution can have strong effects on communities. Both may change concurrently when species colonize a new ecosystem. We know little, however, about the combined effects of ecological and evolutionary change on community structure. We simultaneously examined the effects of top-predator ecology and evolution on freshwater community parameters using recently evolved generalist and specialist ecotypes of three-spine stickleback (Gasterosteus aculeatus). We used a mesocosm experiment to directly examine the effects of ecological (fish presence and density) and evolutionary (phenotypic diversity and specialization) factors on community structure at lower trophic levels. We evaluated zooplankton biomass and composition, periphyton and phytoplankton chlorophyll-a concentration, and net primary production among treatments containing different densities and diversities of stickleback. Our results showed that both ecological and evolutionary differences in the top-predator affect different aspects of community structure and composition. Community structure, specifically the abundance of organisms at each trophic level, was affected by stickleback presence and density, whereas composition of zooplankton was influenced by stickleback diversity and specialization. Primary productivity, in terms of chlorophyll-a concentration and net primary production was affected by ecological but not evolutionary factors. Our results stress the importance of concurrently evaluating both changes in density and phenotypic diversity on the structure and composition of communities. PMID:23573203

Biomass digestibility is predominantly affected by three factors of wall polymer features distinctive in wheat accessions and rice mutants

PubMed Central

2013-01-01

Background Wheat and rice are important food crops with enormous biomass residues for biofuels. However, lignocellulosic recalcitrance becomes a crucial factor on biomass process. Plant cell walls greatly determine biomass recalcitrance, thus it is essential to identify their key factors on lignocellulose saccharification. Despite it has been reported about cell wall factors on biomass digestions, little is known in wheat and rice. In this study, we analyzed nine typical pairs of wheat and rice samples that exhibited distinct cell wall compositions, and identified three major factors of wall polymer features that affected biomass digestibility. Results Based on cell wall compositions, ten wheat accessions and three rice mutants were classified into three distinct groups each with three typical pairs. In terms of group I that displayed single wall polymer alternations in wheat, we found that three wall polymer levels (cellulose, hemicelluloses and lignin) each had a negative effect on biomass digestibility at similar rates under pretreatments of NaOH and H2SO4 with three concentrations. However, analysis of six pairs of wheat and rice samples in groups II and III that each exhibited a similar cell wall composition, indicated that three wall polymer levels were not the major factors on biomass saccharification. Furthermore, in-depth detection of the wall polymer features distinctive in rice mutants, demonstrated that biomass digestibility was remarkably affected either negatively by cellulose crystallinity (CrI) of raw biomass materials, or positively by both Ara substitution degree of non-KOH-extractable hemicelluloses (reverse Xyl/Ara) and p-coumaryl alcohol relative proportion of KOH-extractable lignin (H/G). Correlation analysis indicated that Ara substitution degree and H/G ratio negatively affected cellulose crystallinity for high biomass enzymatic digestion. It was also suggested to determine whether Ara and H monomer have an interlinking with cellulose chains in the future. Conclusions Using nine typical pairs of wheat and rice samples having distinct cell wall compositions and wide biomass saccharification, Ara substitution degree and monolignin H proportion have been revealed to be the dominant factors positively determining biomass digestibility upon various chemical pretreatments. The results demonstrated the potential of genetic modification of plant cell walls for high biomass saccharification in bioenergy crops. PMID:24341349

Modeling the number of car theft using Poisson regression

NASA Astrophysics Data System (ADS)

Zulkifli, Malina; Ling, Agnes Beh Yen; Kasim, Maznah Mat; Ismail, Noriszura

2016-10-01

Regression analysis is the most popular statistical methods used to express the relationship between the variables of response with the covariates. The aim of this paper is to evaluate the factors that influence the number of car theft using Poisson regression model. This paper will focus on the number of car thefts that occurred in districts in Peninsular Malaysia. There are two groups of factor that have been considered, namely district descriptive factors and socio and demographic factors. The result of the study showed that Bumiputera composition, Chinese composition, Other ethnic composition, foreign migration, number of residence with the age between 25 to 64, number of employed person and number of unemployed person are the most influence factors that affect the car theft cases. These information are very useful for the law enforcement department, insurance company and car owners in order to reduce and limiting the car theft cases in Peninsular Malaysia.

Nitrogen fertilizer rate affects root exudation, the rhizosphere microbiome and nitrogen-use-efficiency of maize

USDA-ARS?s Scientific Manuscript database

The composition and function of microbial communities present in the rhizosphere of crops has been linked to edaphic factors and root exudate composition. In this paper, we examined the effect of N fertilizer rate on maize root exudation, the associated rhizosphere community, and nitrogen-use-effici...

Significance of wall structure, macromolecular composition, and surface polymers to the survival and transport of Cryptosporidium parvum Oocysts

USDA-ARS?s Scientific Manuscript database

The structure and composition of the oocyst wall are primary factors determining the survival of Cryptosporidium parvum oocysts outside the host. An external polymer matrix (glycocalyx) may mediate interactions with environmental surfaces and, thus, affect the transport of oocysts in water, soil, an...

Light exposure influences the diurnal oscillation of gut microbiota in mice.

PubMed

Wu, Guangyan; Tang, Wenli; He, Yan; Hu, Jingjuan; Gong, Shenhai; He, Zhanke; Wei, Guoquan; Lv, Liyi; Jiang, Yong; Zhou, Hongwei; Chen, Peng

2018-06-18

The gut microbiota exhibit diurnal compositional and functional oscillations that influence the host homeostasis. However, the upstream factors that affect the microbial oscillations remain elusive. Here, we focused on the potential impact of light exposure, the main factor that affects the host circadian oscillation, on the diurnal oscillations of intestinal microflora to explore the upstream factor that governs the fluctuations of the gut microbes. The gut microbiota of the mice that were underwent regular light/dark (LD) cycles exhibited a robust rhythm at both compositional and functional level, in all parts of the intestine. Comparably, constant darkness (Dark-Dark, DD) led to the loss of the rhythmic oscillations in almost all parts of the intestine. Additionally, the abundance of Clostridia in DD conditions was dramatically enhanced in the small intestine. Our data indicated light exposure is the upstream factor that governs the regular diurnal fluctuations of gut microbiota in vivo. Copyright © 2018 Elsevier Inc. All rights reserved.

Strain intensity factor approach for predicting the strength of continuously reinforced metal matrix composites

NASA Technical Reports Server (NTRS)

Poe, C. C., Jr.

1988-01-01

A method was previously developed to predict the fracture toughness (stress intensity factor at failure) of composites in terms of the elastic constants and the tensile failing strain of the fibers. The method was applied to boron/aluminum composites made with various proportions of 0 to + or - 45 deg plies. Predicted values of fracture toughness were in gross error because widespread yielding of the aluminum matrix made the compliance very nonlinear. An alternate method was developed to predict the strain intensity factor at failure rather than the stress intensity factor because the singular strain field was not affected by yielding as much as the stress field. Strengths of specimens containing crack-like slits were calculated from predicted failing strains using uniaxial stress-strain curves. Predicted strengths were in good agreement with experimental values, even for the very nonlinear laminates that contained only + or - 45 deg plies. This approach should be valid for other metal matrix composites that have continuous fibers.

Factors affecting the shear strength behavior of municipal solid wastes.

PubMed

Pulat, Hasan Firat; Yukselen-Aksoy, Yeliz

2017-11-01

In this study, the shear strength behavior of European (E-1), Turkey (T-1), and United States of America (U-1) average synthetic municipal solid waste (MSW) compositions were investigated. The large-scale direct shear tests were conducted using fresh and aged MSW samples collected from the Manisa Landfill. The natural samples' test results were compared with synthetic samples. The affecting factors such as ageing, waste composition, and waste type (synthetic and natural) on the shear strength of MSWs were investigated. The effect of composition was evaluated using three main and six modified synthetic MSW compositions. In addition to the synthetic fresh MSW samples, synthetic aged samples were also used. Angle of shearing resistance decreased with increasing organic content whereas cohesion intercept increased with increasing organic content. The fresh and aged wastes with higher coarse fraction lead to a higher angle of shearing resistance. The synthetic aged samples had higher internal friction angles but lower cohesion values than the synthetic fresh samples. Waste with average European composition had the highest internal friction angle as it has the highest fibrous content. On the other hand, the highest cohesion belonged to the Turkey composition, which had the highest organic matter ratio. The main differences between E-1, T-1 and U-1 samples in terms of compositions were observed. The results of this study indicated that shear strength of waste significantly depends on composition and hence a site specific evaluation is recommended. Copyright © 2017 Elsevier Ltd. All rights reserved.

Factors affecting the microstructure and mechanical properties of Ti-Al3Ti core-shell-structured particle-reinforced Al matrix composites

NASA Astrophysics Data System (ADS)

Guo, Baisong; Yi, Jianhong; Ni, Song; Shen, Rujuan; Song, Min

2016-04-01

This work studied the effects of matrix powder and sintering temperature on the microstructure and mechanical properties of in situ formed Ti-Al3Ti core-shell-structured particle-reinforced pure Al-based composites. It has been shown that both factors have significant effects on the morphology of the reinforcements and densification behaviour of the composites. Due to the strong interfacial bonding and the limitation of the crack propagation in the intermetallic shell during deformation by soft Al matrix and Ti core, the composite fabricated using fine spherical-shaped Al powder and sintered at 570 °C for 5 h has the optimal combination of the overall mechanical properties. The study provides a direction for the optimum combination of high strength and ductility of the composites by adjusting the fabrication parameters.

Machinability Study on Milling Kenaf Fiber Reinforced Plastic Composite Materials using Design of Experiments

NASA Astrophysics Data System (ADS)

Azmi, H.; Haron, C. H. C.; Ghani, J. A.; Suhaily, M.; Yuzairi, A. R.

2018-04-01

The surface roughness (Ra) and delamination factor (Fd) of a milled kenaf reinforced plastic composite materials are depending on the milling parameters (spindle speed, feed rate and depth of cut). Therefore, a study was carried out to investigate the relationship between the milling parameters and their effects on a kenaf reinforced plastic composite materials. The composite panels were fabricated using vacuum assisted resin transfer moulding (VARTM) method. A full factorial design of experiments was use as an initial step to screen the significance of the parameters on the defects using Analysis of Variance (ANOVA). If the curvature of the collected data shows significant, Response Surface Methodology (RSM) is then applied for obtaining a quadratic modelling equation that has more reliable in expressing the optimization. Thus, the objective of this research is obtaining an optimum setting of milling parameters and modelling equations to minimize the surface roughness (Ra) and delamination factor (Fd) of milled kenaf reinforced plastic composite materials. The spindle speed and feed rate contributed the most in affecting the surface roughness and the delamination factor of the kenaf composite materials.

Modeling the effects of harvest alternatives on mitigating oak decline in a Central Hardwood Forest landscape

Treesearch

Wen J. Wang; Hong S. He; Martin A. Spetich; Stephen R. Shifley; Frank R. III Thompson; Jacob S. Fraser

2013-01-01

Oak decline is a process induced by complex interactions of predisposing factors, inciting factors, and contributing factors operating at tree, stand, and landscape scales. It has greatly altered species composition and stand structure in affected areas. Thinning, clearcutting, and group selection are widely adopted harvest alternatives for reducing forest...

A new method of determining moisture gradient in wood

Treesearch

Zhiyong Cai

2008-01-01

Moisture gradient in wood and wood composites is one of most important factors that affects both physical stability and mechanical performance. This paper describes a method for measuring moisture gradient in lumber and engineering wood composites as it varies across material thickness. This innovative method employs a collimated radiation beam (x rays or [gamma] rays...

Chemical composition of acid precipitation in central Texas

Treesearch

Hal B. H., Jr. Cooper; Jerry M. Demo

1976-01-01

Studies were undertaken to determine factors affecting composition of acidic precipitation formation in the Austin area of Central Texas. The study was initiated to determine background levels of acid and alkalinity producing constituents in an area with elevated natural dust levels from nearby limestone rock formations. Results showed normal rainfall pH values of 6.5...

Gravity as a factor in the animal environment.

NASA Technical Reports Server (NTRS)

Smith, A. H.

1972-01-01

Review of current knowledge, research, and research planning on the influence of gravity upon living organisms. Discussed factors affecting the adaptability of animals to increased acceleration fields include age, sex, posture, and body size. Affected functions and aspects reviewed cover growth and mature body size, body composition, maintenance feed requirements, and feed utilization efficiency. It is expected that research involving the exposure of animals to altered gravity states will lead to new biological concepts of very broad importance.

Progressive damage, fracture predictions and post mortem correlations for fiber composites

NASA Technical Reports Server (NTRS)

1985-01-01

Lewis Research Center is involved in the development of computational mechanics methods for predicting the structural behavior and response of composite structures. In conjunction with the analytical methods development, experimental programs including post failure examination are conducted to study various factors affecting composite fracture such as laminate thickness effects, ply configuration, and notch sensitivity. Results indicate that the analytical capabilities incorporated in the CODSTRAN computer code are effective in predicting the progressive damage and fracture of composite structures. In addition, the results being generated are establishing a data base which will aid in the characterization of composite fracture.

Self-lubricating polymer composites and polymer transfer film lubrication for space applications

NASA Technical Reports Server (NTRS)

Fusaro, Robert L.

1990-01-01

The use of self-lubricating polymers and polymer composites in space is somewhat limited today. In general, they are only used when other methods are inadequate. There is potential, however, for these materials to make a significant impact on future space missions if properly utilized. Some of the different polymers and fillers used to make self-lubricating composites are surveyed. The mechanisms of composite lubrication and wear, the theory behind transfer film lubricating mechanisms, and some factors which affect polymer composite wear and transfer are examined. In addition, some of the current space tribology application areas for self-lubricating polymer composites and polymer transfer are mentioned.

Landscape determinants of exchangeable calcium and magnesium in Ozark Highland forest soils

Treesearch

John M. Kabrick; Keith W. Goyne; Zhaofei Fan; Dennis Meinert

2011-01-01

Exchangeable base cations, particularly Ca and Mg, largely govern soil acidity and, consequently, plant species composition in temperate forests. Although studies have identified soil and terrain characteristics affecting exchangeable Ca and Mg, few studies have identified the relative importance of factors affecting Ca and Mg distribution across landscapes. Objectives...

An inventory of factors that affect polysaccharide production by Phaeocystis globosa

NASA Astrophysics Data System (ADS)

van Rijssel, M.; Janse, I.; Noordkamp, D. J. B.; Gieskes, W. W. C.

2000-08-01

Phaeocystis material contains polysaccharides that are built from at least eight different monosaccharides. Differences have been reported between the carbohydrate composition of different Phaeocystis species, and also between samples taken from Phaeocystis globosa blooms in different areas. In order to elucidate factors that could play a role in determining variation in carbohydrate composition and production, a number of Phaeocystis globosa strains were studied under laboratory conditions. Although there was a clear distinction of a northern and a southern cluster in the Phaeocystis globosa strains based on RAPD analysis, the differences in the composition of the mucopolysaccharides were relatively small. The contribution of glucose, however, ranged from 7-85% of total sugars. A strain that was cultured in seawaters of diverse origin produced polysaccharides of a different composition, suggesting the effect of environmental factors. The presence of bacteria affected neither the amount, nor the composition of the carbohydrates that were produced by Phaeocystis globosa. Glucose is part of both the intracellular polysaccharide pool and of the mucopolysaccharides in the colony matrix. Using specific digestion of the intracellular chrysolaminaran by laminarinase, the distribution of polysaccharides over different pools could be assessed. During growth of an axenic, mucus-producing strain, the portion of glucose present as chrysolaminaran appeared to increase. The polyglucose that was not digested by laminarinase remains unidentified. This study shows that environmental factors rather than strain differences determine differences in the sugar composition of Phaeocystis globosa, especially with respect to the glucose content of the material. A difference in the contribution of glucose could be correlated to the portion of cells in the culture that are not in the colonies. Our study emphasises that for studying polysaccharide dynamics in Phaeocystis globosa it is important to be able to discriminate between the different polysaccharide pools. Preliminary results of an enzymatic approach were promising

Comparison of cadmium adsorption onto chitosan and epichlorohydrin crosslinked chitosan/eggshell composite

NASA Astrophysics Data System (ADS)

Rahmi; Marlina; Nisfayati

2018-05-01

The use of chitosan and epichlorohydrin crosslinked chitosan/eggshell composite for cadmium adsorption from water were investigated. The factors affecting adsorption such as pH and contact time were considered. The results showed that the optimum pH of adsorption was pH = 6.0 and the equilibrium time of adsorption was 40 min. The adsorption isotherm of Cd ions onto chitosan and composite were well fitted to Langmuir equation. The maximum adsorption capacity (fitting by Langmuir model) of chitosan and composite were 1.008 and 11.7647 mg/g, respectively. Adsorption performance of composite after regeneration was better than chitosan.

Compositing multitemporal remote sensing data sets

USGS Publications Warehouse

Qi, J.; Huete, A.R.; Hood, J.; Kerr, Y.

1993-01-01

To eliminate cloud and atmosphere-affected pixels, the compositing of multi temporal remote sensing data sets is done by selecting the maximum vale of the normalized different vegetation index (NDVI) within a compositing period. The NDVI classifier, however, is strongly affected by surface type and anisotropic properties, sensor viewing geometries, and atmospheric conditions. Consequently, the composited, multi temporal, remote sensing data contain substantial noise from these external conditions. Consequently, the composited, multi temporal, remote sensing data contain substantial noise from these external effects. To improve the accuracy of compositing products, two key approaches can be taken: one is to refine the compositing classifier (NDVI) and the other is to improve existing compositing algorithms. In this project, an alternative classifier was developed and an alternative pixel selection criterion was proposed for compositing. The new classifier and the alternative compositing algorithm were applied to an advanced very high resolution radiometer data set of different biome types in the United States. The results were compared with the maximum value compositing and the best index slope extraction algorithms. The new approaches greatly reduced the high frequency noises related to the external factors and repainted more reliable data. The results suggest that the geometric-optical canopy properties of specific biomes may be needed in compositing. Limitations of the new approaches include the dependency of pixel selection on the length of the composite period and data discontinuity.

Effect of the Microstructure on the Fracture Mode of Short-Fiber Reinforced Plastic Composites

NASA Astrophysics Data System (ADS)

Nishikawa, Masaaki; Okabe, Tomonaga; Takeda, Nobuo

A numerical simulation was presented to discuss the microscopic damage and its influence on the strength and energy-absorbing capability of short-fiber reinforced plastic composites. The dominant damage includes matrix crack and/or interfacial debonding, when the fibers are shorter than the critical length for fiber breakage. The simulation addressed the matrix crack with a continuum damage mechanics (CDM) model and the interfacial debonding with an embedded process zone (EPZ) model. Fictitious free-edge effects on the fracture modes were successfully eliminated with the periodic-cell simulation. The advantage of our simulation was pointed out by demonstrating that the simulation with edge effects significantly overestimates the dissipative energy of the composites. We then investigated the effect of the material microstructure on the fracture modes in the composites. The simulated results clarified that the inter-fiber distance affects the breaking strain of the composites and the fiber-orientation angle affects the position of the damage initiation. These factors influence the strength and energy-absorbing capability of short fiber-reinforced composites.

Factors affecting body composition in preterm infants: Assessment techniques and nutritional interventions.

PubMed

Strydom, K; Van Niekerk, E; Dhansay, M A

2017-10-28

Limited research has been conducted that elucidates the growth and body composition of preterm infants. It is known that these infants do not necessarily achieve extra-utero growth rates and body composition similar to those of their term counterparts. Preterm infants, who have difficulty in achieving these growth rates, could suffer from growth failure. These infants display an increased intra-abdominal adiposity and abnormal body composition when they achieve catch-up growth. These factors affect the quality of weight gain, as these infants are not only shorter and lighter than term infants, they also have more fat mass (FM) and less fat-free mass (FFM), resulting in a higher total fat percentage. This could cause metabolic syndrome and cardiovascular problems to develop later in a preterm infant's life. The methods used to determine body composition in preterm infants should be simple, quick, non-invasive and inexpensive. Available literature was reviewed and the Dauncey anthropometric model, which includes skinfold thickness at two primary sites and nine body dimensions, is considered in this review the best method to accurately determine body composition in preterm infants, especially in resource-poor countries. It is imperative to accurately assess the quality of growth and body composition of this fragile population in order to determine whether currently prescribed nutritional interventions are beneficial to the overall nutritional status and quality of life-in the short- and long-term-of the preterm infant, and to enable timely implementation of appropriate interventions, if required. Copyright © 2017. Published by Elsevier B.V.

Progress in dimethacrylate-based dental composite technology and curing efficiency.

PubMed

Leprince, Julian G; Palin, William M; Hadis, Mohammed A; Devaux, Jacques; Leloup, Gaetane

2013-02-01

This work aims to review the key factors affecting the polymerization efficiency of light-activated resin-based composites. The different properties and methods used to evaluate polymerization efficiency will also be critically appraised with focus on the developments in dental photopolymer technology and how recent advances have attempted to improve the shortcomings of contemporary resin composites. Apart from the classical literature on the subject, the review focused in particular on papers published since 2009. The literature research was performed in Scopus with the terms "dental resin OR dimethacrylate". The list was screened and all papers relevant to the objectives of this work were included. Though new monomer technologies have been developed and some of them already introduced to the dental market, dimethacrylate-based composites still currently represent the vast majority of commercially available materials for direct restoration. The photopolymerization of resin-based composites has been the subject of numerous publications, which have highlighted the major impact of the setting process on material properties and quality of the final restoration. Many factors affect the polymerization efficiency, be they intrinsic; photoinitiator type and concentration, viscosity (co-monomer composition and ratio, filler content) and optical properties, or extrinsic; light type and spectrum, irradiation parameters (radiant energy, time and irradiance), curing modes, temperature and light guide tip positioning. : This review further highlights the apparent need for a more informative approach by manufacturers to relay appropriate information in order for dentists to optimize material properties of resin composites used in daily practice. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

More than Numbers: Individual and Contextual Factors in How Gender Diversity Affects Women's Well-Being

ERIC Educational Resources Information Center

Miner-Rubino, Kathi; Settles, Isis H.; Stewart, Abigail J.

2009-01-01

This study examined factors related to workplace gender diversity in a sample of 87 college-educated White women. Specifically, we investigated the moderating effects of one individual difference variable (sensitivity to sexism) and one contextual variable (perceptions of the workplace climate) in the relationship between the gender composition at…

Methods for estimating expected blood alcohol concentration

DOT National Transportation Integrated Search

1980-08-01

Estimates of blood alcohol concentration (BAC) typically are based on the amount of alcohol consumed per pound bodyweight. This method fails to consider either food intake or body composition, factors which significantly affect BAC. A laboratory expe...

Study on the quality of FRP fishing vessel based on improved Fishbone Chart

NASA Astrophysics Data System (ADS)

Sui, J. H.; Yu, Y. F.; Du, Q. F.; Jiang, D. W.

2018-01-01

The construction quality of FRP fishing vessels influences their production, use and industry development. In order to explore the factors that affect the construction quality of FRP fishing vessels, key factors affecting the construction quality of FRP fishing vessels are determined based on the quality problems of FRP fishing vessels constructed. The improved Fishbone Chart is used to analyze the eight factors of “human, machine, material, process, environment, inspection, design and information”. Taking the factors that affect the construction quality of FRP fishing vessels as the central target, the eight influencing factors were condensed into five aspects and a composite Fishbone Chart is drawn. The Fishbone Chart is used as the basic model, the influencing factors are sorted, screened and discriminated, and the system model convenient for construction site management and control is established. Finally, the causes of poor construction of FRP fishing vessels are analyzed and discussed, and relevant suggestions are put forward.

Advances in fruit aroma volatile research.

PubMed

El Hadi, Muna Ahmed Mohamed; Zhang, Feng-Jie; Wu, Fei-Fei; Zhou, Chun-Hua; Tao, Jun

2013-07-11

Fruits produce a range of volatile compounds that make up their characteristic aromas and contribute to their flavor. Fruit volatile compounds are mainly comprised of esters, alcohols, aldehydes, ketones, lactones, terpenoids and apocarotenoids. Many factors affect volatile composition, including the genetic makeup, degree of maturity, environmental conditions, postharvest handling and storage. There are several pathways involved in volatile biosynthesis starting from lipids, amino acids, terpenoids and carotenoids. Once the basic skeletons are produced via these pathways, the diversity of volatiles is achieved via additional modification reactions such as acylation, methylation, oxidation/reduction and cyclic ring closure. In this paper, we review the composition of fruit aroma, the characteristic aroma compounds of several representative fruits, the factors affecting aroma volatile, and the biosynthetic pathways of volatile aroma compounds. We anticipate that this review would provide some critical information for profound research on fruit aroma components and their manipulation during development and storage.

Effect of water volume based on water absorption and mixing time on physical properties of tapioca starch – wheat composite bread

NASA Astrophysics Data System (ADS)

Prameswari, I. K.; Manuhara, G. J.; Amanto, B. S.; Atmaka, W.

2018-05-01

Tapioca starch application in bread processing change water absorption level by the dough, while sufficient mixing time makes the optimal water absorption. This research aims to determine the effect of variations in water volume and mixing time on physical properties of tapioca starch – wheat composite bread and the best method for the composite bread processing. This research used Complete Randomized Factorial Design (CRFD) with two factors: variations of water volume (111,8 ml, 117,4 ml, 123 ml) and mixing time (16 minutes, 17 minutes 36 seconds, 19 minutes 12 seconds). The result showed that water volume significantly affected on dough volume, bread volume and specific volume, baking expansion, and crust thickness. Mixing time significantly affected on dough volume and specific volume, bread volume and specific volume, baking expansion, bread height, and crust thickness. While the combination of water volume and mixing time significantly affected for all physical properties parameters except crust thickness.

The Human Salivary Microbiome Is Shaped by Shared Environment Rather than Genetics: Evidence from a Large Family of Closely Related Individuals.

PubMed

Shaw, Liam; Ribeiro, Andre L R; Levine, Adam P; Pontikos, Nikolas; Balloux, Francois; Segal, Anthony W; Roberts, Adam P; Smith, Andrew M

2017-09-12

The human microbiome is affected by multiple factors, including the environment and host genetics. In this study, we analyzed the salivary microbiomes of an extended family of Ashkenazi Jewish individuals living in several cities and investigated associations with both shared household and host genetic similarities. We found that environmental effects dominated over genetic effects. While there was weak evidence of geographical structuring at the level of cities, we observed a large and significant effect of shared household on microbiome composition, supporting the role of the immediate shared environment in dictating the presence or absence of taxa. This effect was also seen when including adults who had grown up in the same household but moved out prior to the time of sampling, suggesting that the establishment of the salivary microbiome earlier in life may affect its long-term composition. We found weak associations between host genetic relatedness and microbiome dissimilarity when using family pedigrees as proxies for genetic similarity. However, this association disappeared when using more-accurate measures of kinship based on genome-wide genetic markers, indicating that the environment rather than host genetics is the dominant factor affecting the composition of the salivary microbiome in closely related individuals. Our results support the concept that there is a consistent core microbiome conserved across global scales but that small-scale effects due to a shared living environment significantly affect microbial community composition. IMPORTANCE Previous research shows that the salivary microbiomes of relatives are more similar than those of nonrelatives, but it remains difficult to distinguish the effects of relatedness and shared household environment. Furthermore, pedigree measures may not accurately measure host genetic similarity. In this study, we include genetic relatedness based on genome-wide single nucleotide polymorphisms (SNPs) (rather than pedigree measures) and shared environment in the same analysis. We quantify the relative importance of these factors by studying the salivary microbiomes in members of a large extended Ashkenazi Jewish family living in different locations. We find that host genetics plays no significant role and that the dominant factor is the shared environment at the household level. We also find that this effect appears to persist in individuals who have moved out of the parental household, suggesting that aspects of salivary microbiome composition established during upbringing can persist over a time scale of years. Copyright © 2017 Shaw et al.

Treatment-Associated Changes in Body Composition, Health Behaviors, and Mood as Predictors of Change in Body Satisfaction in Obese Women: Effects of Age and Race/Ethnicity

ERIC Educational Resources Information Center

Annesi, James J.; Tennant, Gisèle A.; Mareno, Nicole

2014-01-01

A lack of satisfaction with one's body is common among women with obesity, often prompting unhealthy "dieting." Beyond typically slow improvements in weight and body composition, behavioral factors might also affect change in body satisfaction. Age and race/ethnicity (African American vs. White) might moderate such change. Obese women (N…

Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0)

DTIC Science & Technology

2010-05-01

application of irrigation water can alter soil characteristics (e.g., color, redox features, and salt content) and vegetation of affected areas. Long... affected areas in both intended and unintended ways, through leakage of water from delivery channels and ditches, application of water to irrigated...indicators described in this chapter. Many factors in addition to site wetness affect the composition of the plant community in an area, including

Factors affecting marginal integrity of class II bulk-fill composite resin restorations

PubMed Central

Savadi Oskoee, Siavash; Bahari, Mahmoud; Jafari Navimipour, Elmira; Ajami, Amir Ahmad; Ghiasvand, Negar; Savadi Oskoee, Ayda

2017-01-01

Background. Bulk-fill composite resins are a new type of resin-based composite resins, claimed to have the capacity to be placed in thick layers, up to 4 mm. This study was carried out to evaluate factors affecting gap formation in Cl II cavities restored using the bulk-fill technique. Methods. A total of 60 third molars were used in this study. Two Cl II cavities were prepared in each tooth, one on the mesial aspect 1 mm coronal to the CEJ and one on the distal aspect 1 mm apical to the CEJ. The teeth were divided into 4 groups: A: The cavities were restored using the bulk-fill technique with Filtek P90 composite resin and its adhesive system and light-cured with quartz tungsten halogen (QTH) light-curing unit. B: The cavities were restored similar to that in group A but light-cured with an LED light-curing unit. C: The cavities were restored using the bulk-fill technique with X-tra Fil composite resin and Clearfil SE Bond adhesive system and light-cured with a QTH curing unit. D: The cavities were restored similar to that in group C but light-cured with an LED light-curing unit. The gaps were examined under a stereomicroscope at ×60. Data were analyzed with General Linear Model test. In cases of statistical significance (P<0.05), post hoc Bonferroni test was used for further analyses. Results. The light-curing unit type had no effect on gap formation. However, the results were significant in relation to the composite resin type and margin location (P<0.001). The cumulative effects of light-curing unit*gingival margin and light-curing unit*composite resin type were not significant; however, the cumulative effect of composite rein type*gingival margin was significant (P=0.04) Conclusion. X-tra Fil composite exhibited smaller gaps compared with Filtek P90 composite with both light-curing units. Both composite resins exhibited smaller gaps at enamel margins. PMID:28748051

Relationship between diet, the gut microbiota, and brain function.

PubMed

Tengeler, Anouk C; Kozicz, Tamas; Kiliaan, Amanda J

2018-04-28

The human intestinal microbiota, comprising trillions of microorganisms, exerts a substantial effect on the host. The microbiota plays essential roles in the function and development of several physiological processes, including those in the brain. A disruption in the microbial composition of the gut has been associated with many metabolic, inflammatory, neurodevelopmental, and neurodegenerative disorders. Nutrition is one of several key factors that shape the microbial composition during infancy and throughout life, thereby affecting brain structure and function. This review examines the effect of the gut microbiota on brain function. The ability of external factors, such as diet, to influence the microbial composition implies a certain vulnerability of the gut microbiota. However, it also offers a potential therapeutic strategy for ameliorating symptoms of mental and physical disorders. Therefore, this review examines the potential effect of nutritional components on gut microbial composition and brain function.

Investigation of Springback Associated with Composite Material Component Fabrication (MSFC Center Director's Discretionary Fund Final Report, Project 94-09)

NASA Technical Reports Server (NTRS)

Benzie, M. A.

1998-01-01

The objective of this research project was to examine processing and design parameters in the fabrication of composite components to obtain a better understanding and attempt to minimize springback associated with composite materials. To accomplish this, both processing and design parameters were included in a Taguchi-designed experiment. Composite angled panels were fabricated, by hand layup techniques, and the fabricated panels were inspected for springback effects. This experiment yielded several significant results. The confirmation experiment validated the reproducibility of the factorial effects, error recognized, and experiment as reliable. The material used in the design of tooling needs to be a major consideration when fabricating composite components, as expected. The factors dealing with resin flow, however, raise several potentially serious material and design questions. These questions must be dealt with up front in order to minimize springback: viscosity of the resin, vacuum bagging of the part for cure, and the curing method selected. These factors directly affect design, material selection, and processing methods.

Cachexia and adiposity in rheumatoid arthritis. Relevance for disease management and clinical outcomes.

PubMed

Challal, Salima; Minichiello, Emeline; Boissier, Marie-Christophe; Semerano, Luca

2016-03-01

Altered body composition is a frequent finding in rheumatoid arthritis and is associated with the two major outcomes of the disease: disability and cardiovascular mortality. It is estimated that up to two thirds of patients may be affected by loss of lean mass, the so-called rheumatoid cachexia. Hence, body weight being equal, the relative amount of lean mass is lower and that of body fat is higher in rheumatoid arthritis patients vs. healthy controls. Both disease-related factors and other factors, like drug treatments, physical activity and nutrition contribute to modify body composition in rheumatoid arthritis. The effect of pharmacological treatments, and notably of anti-TNF drugs, on body composition is controversial. Conversely, training programs to stimulate muscle growth can restore lean mass and reduce adiposity. There is good evidence that amelioration of body composition ameliorates function and reduces disability. Currently, there is no evidence that interventions that modify body composition can reduce cardiovascular morbidity and mortality in rheumatoid arthritis. Copyright © 2015. Published by Elsevier SAS.

Serum 25-hydroxyvitamin D3 and body composition in an elderly cohort from Germany: a cross-sectional study

PubMed Central

2012-01-01

Background Emerging evidence indicates that there is an association between vitamin D and obesity. The aim of this study was to investigate whether the level of serum 25-hydroxyvitamin D3 [25(OH)D3] in the elderly is influenced by parameters of anthropometry and body composition independent of potential confounding lifestyle factors and the level of serum intact parathyroid hormone (iPTH). Methods Cross-sectional data of 131 independently living participants (90 women, 41 men; aged 66–96 years) of the longitudinal study on nutrition and health status in senior citizens of Giessen, Germany were analysed. Concentrations of 25(OH)D3 and iPTH were ascertained by an electrochemiluminescence immunoassay. Body composition was measured by a bioelectrical impedance analysis. We performed univariate and multiple regression analyses to examine the influence of body composition on 25(OH)D3 with adjustments for age, iPTH and lifestyle factors. Results In univariate regression analyses, 25(OH)D3 was associated with body mass index (BMI), hip circumference and total body fat (TBF) in women, but not in men. Using multiple regression analyses, TBF was shown to be a negative predictor of 25(OH)D3 levels in women even after controlling for age, lifestyle and iPTH (ß = −0.247; P = 0.016), whereas the associations between BMI, hip circumference and 25(OH)D3 lost statistical significance after adjusting for iPTH. In men, 25(OH)D3 was not affected by anthropometric or body composition variables. Conclusions The results indicate that 25(OH)D3 levels are affected by TBF, especially in elderly women, independent of lifestyle factors and iPTH. PMID:22607088

Barrier Island Morphology and Sediment Characteristics Affect the Recovery of Dune Building Grasses following Storm-Induced Overwash

PubMed Central

Brantley, Steven T.; Bissett, Spencer N.; Young, Donald R.; Wolner, Catherine W. V.; Moore, Laura J.

2014-01-01

Barrier islands are complex and dynamic systems that provide critical ecosystem services to coastal populations. Stability of these systems is threatened by rising sea level and the potential for coastal storms to increase in frequency and intensity. Recovery of dune-building grasses following storms is an important process that promotes topographic heterogeneity and long-term stability of barrier islands, yet factors that drive dune recovery are poorly understood. We examined vegetation recovery in overwash zones on two geomorphically distinct (undisturbed vs. frequently overwashed) barrier islands on the Virginia coast, USA. We hypothesized that vegetation recovery in overwash zones would be driven primarily by environmental characteristics, especially elevation and beach width. We sampled species composition and environmental characteristics along a continuum of disturbance from active overwash zones to relict overwash zones and in adjacent undisturbed environments. We compared species assemblages along the disturbance chronosequence and between islands and we analyzed species composition data and environmental measurements with Canonical Correspondence Analysis to link community composition with environmental characteristics. Recovering and geomorphically stable dunes were dominated by Ammophila breviligulata Fernaud (Poaceae) on both islands while active overwash zones were dominated by Spartina patens (Aiton) Muhl. (Poaceae) on the frequently disturbed island and bare sand on the less disturbed island. Species composition was associated with environmental characteristics only on the frequently disturbed island (p = 0.005) where A. breviligulata was associated with higher elevation and greater beach width. Spartina patens, the second most abundant species, was associated with larger sediment grain size and greater sediment size distribution. On the less frequently disturbed island, time since disturbance was the only factor that affected community composition. Thus, factors driving the abundance of dune-building grasses and subsequent recovery of dunes varied between the two geomorphically distinct islands. PMID:25148028

Effect of one low thinning on cove and slope hardwoods in the New Jersey highlands

Treesearch

H. B. Tepper; G. T. Bamford

1959-01-01

The exact value of thinning in managing hardwoods is not yet known. Further study of the many factors that affect thinning results is needed. These factors include methods and intensities of thinning, ages at which thinnings are started or repeated, effects of species composition in mixed stands, and influence of site index on response to thinning.

Factors affecting plant species composition of hedgerows: relative importance and hierarchy

NASA Astrophysics Data System (ADS)

Deckers, Bart; Hermy, Martin; Muys, Bart

2004-07-01

Although there has been a clear quantitative and qualitative decline in traditional hedgerow network landscapes during last century, hedgerows are crucial for the conservation of rural biodiversity, functioning as an important habitat, refuge and corridor for numerous species. To safeguard this conservation function, insight in the basic organizing principles of hedgerow plant communities is needed. The vegetation composition of 511 individual hedgerows situated within an ancient hedgerow network landscape in Flanders, Belgium was recorded, in combination with a wide range of explanatory variables, including a selection of spatial variables. Non-parametric statistics in combination with multivariate data analysis techniques were used to study the effect of individual explanatory variables. Next, variables were grouped in five distinct subsets and the relative importance of these variable groups was assessed by two related variation partitioning techniques, partial regression and partial canonical correspondence analysis, taking into account explicitly the existence of intercorrelations between variables of different factor groups. Most explanatory variables affected significantly hedgerow species richness and composition. Multivariate analysis showed that, besides adjacent land use, hedgerow management, soil conditions, hedgerow type and origin, the role of other factors such as hedge dimensions, intactness, etc., could certainly not be neglected. Furthermore, both methods revealed the same overall ranking of the five distinct factor groups. Besides a predominant impact of abiotic environmental conditions, it was found that management variables and structural aspects have a relatively larger influence on the distribution of plant species in hedgerows than their historical background or spatial configuration.

Guinea pig for meat production: A systematic review of factors affecting the production, carcass and meat quality.

PubMed

Sánchez-Macías, Davinia; Barba-Maggi, Lida; Morales-delaNuez, Antonio; Palmay-Paredes, Julio

2018-09-01

In developing countries, interest in guinea pig farming is growing exponentially because it provides a regular source of high quality animal protein for domestic consumption. Guinea pigs (Cavia porcellus) are prolific animals, grow and are capable of reproduction on a flexible diet, and are adaptable to a wide range of climates. This article mainly reviews findings on guinea pig meat production, including factors affecting raising guinea pigs, carcass and meat quality. We also present some studies that describe biological and pathologic effects on carcass component composition. During the last decades no standard procedure has been established for guinea pig carcass evaluation, which makes very difficult any comparison of results with other studies around the world. Herein we highlight a variety of factors that significantly affect carcass and meat quality. Some of these factors are production systems, environmental and genetic factors, management systems, the diet and health status, age, sex and reproductive management. Copyright © 2018 Elsevier Ltd. All rights reserved.

A Titan Explorer Mission Utilizing Solar Electric Propulsion and Chemical Propulsion Systems

NASA Technical Reports Server (NTRS)

Cupples, Michael; Coverstone, Vicki

2003-01-01

Mission and Systems analyses were performed for a Titan Explorer Mission scenario utilizing medium class launch vehicles, solar electric propulsion system (SEPS) for primary interplanetary propulsion, and chemical propulsion for capture at Titan. An examination of a range of system factors was performed to determine their affect on the payload delivery capability to Titan. The effect of varying the launch vehicle, solar array power, associated number of SEPS thrusters, chemical propellant combinations, tank liner thickness, and tank composite overwrap stress factor was investigated. This paper provides a parametric survey of the aforementioned set of system factors, delineating their affect on Titan payload delivery, as well as discussing aspects of planetary capture methodology.

Phylogenetic factorization of compositional data yields lineage-level associations in microbiome datasets.

PubMed

Washburne, Alex D; Silverman, Justin D; Leff, Jonathan W; Bennett, Dominic J; Darcy, John L; Mukherjee, Sayan; Fierer, Noah; David, Lawrence A

2017-01-01

Marker gene sequencing of microbial communities has generated big datasets of microbial relative abundances varying across environmental conditions, sample sites and treatments. These data often come with putative phylogenies, providing unique opportunities to investigate how shared evolutionary history affects microbial abundance patterns. Here, we present a method to identify the phylogenetic factors driving patterns in microbial community composition. We use the method, "phylofactorization," to re-analyze datasets from the human body and soil microbial communities, demonstrating how phylofactorization is a dimensionality-reducing tool, an ordination-visualization tool, and an inferential tool for identifying edges in the phylogeny along which putative functional ecological traits may have arisen.

Factors affecting the reproductive success of dominant male meerkats.

PubMed

Spong, Göran F; Hodge, Sarah J; Young, Andrew J; Clutton-Brock, Tim H

2008-05-01

Identifying traits that affect the reproductive success of individuals is fundamental for our understanding of evolutionary processes. In cooperative breeders, a dominant male typically restricts mating access to the dominant female for extended periods, resulting in pronounced variation in reproductive success among males. This may result in strong selection for traits that increase the likelihood of dominance acquisition, dominance retention and reproductive rates while dominant. However, despite considerable research on reproductive skew, few studies have explored the factors that influence these three processes among males in cooperative species. Here we use genetic, behavioural and demographic data to investigate the factors affecting reproductive success in dominant male meerkats (Suricata suricatta). Our data show that dominant males sire the majority of all offspring surviving to 1 year. A male's likelihood of becoming dominant is strongly influenced by age, but not by weight. Tenure length and reproductive rate, both important components of dominant male reproductive success, are largely affected by group size and composition, rather than individual traits. Dominant males in large groups have longer tenures, but after this effect is controlled, male tenure length also correlates negatively to the number of adult females in the group. Male reproductive rate also declines as the number of intra- and extra-group competitors increases. As the time spent in the dominant position and reproductive rate while dominant explain > 80% of the total variance in reproductive success, group composition thus has major implications for male reproductive success.

Occupational gender composition and mild to severe depression in a Swedish cohort: The impact of psychosocial work factors.

PubMed

Nyberg, Anna; Magnusson Hanson, Linda L; Leineweber, Constanze; Hammarström, Anne; Theorell, Töres

2018-05-01

The aim of the present study was to investigate associations between occupational gender composition, psychosocial work factors and mild to severe depression in Swedish women and men with various educational backgrounds. The study included 5560 participants from two waves of the Swedish Longitudinal Occupational Survey of Health, an approximately representative sample of the Swedish working population. Odds ratios (OR) and 95% confidence intervals of mild to severe depression in 2014 were estimated for five strata of occupational gender composition with >20-40%, >40-60%, >60-80% and >80-100% women, using 0-20% women as the reference. Analyses were stratified by gender and education. Job strain, organisational injustice, poor social support and effort-reward imbalance in 2012 were added in separate models, and changes in OR of mild to severe depression for strata of occupational gender composition were evaluated. Among women, the odds of mild to severe depression did not vary by occupational gender composition. Among men with low to intermediate education, the odds were higher in the stratum with >80-100% women, and among men with high education, the odds were higher in strata with >20-40% and >60-80% women. Psychosocial work factors affected the odds ratios of mild to severe depression, but most of the variation remained unexplained. Odds of mild to severe depression appeared to vary by occupational gender composition among Swedish men but not women. This variation seemed only to a small extent to be explained by psychosocial work factors.

Factors affecting alkali jarosite precipitation

NASA Astrophysics Data System (ADS)

Dutrizac, J. E.

1983-12-01

Several factors affecting the precipitation of the alkali jarosites (sodium jarosite, potassium jarosite, rubidium jarosite, and ammonium jarosite) have been studied systematically using sodium jarosite as the model. The pH of the reacting solution exercises a major influence on the amount of jarosite formed, but has little effect on the composition of the washed product. Higher temperatures significantly increase the yield and slightly raise the alkali content of the jarosites. The yield and alkali content both increase greatly with the alkali concentration to about twice the stoichiometric requirement but, thereafter, remain nearly constant. At 97 °C, the amount of product increases with longer retention times to about 15 hours, but more prolonged reaction times are without significant effect on the amount or composition of the jarosite. Factors such as the presence of seed or ionic strength have little effect on the yield or jarosite composition. The amount of precipitate augments directly as the iron concentration of the solution increases, but the product composition is nearly independent of this variable. A significant degree of agitation is necessary to suspend the product and to prevent the jarosite from coating the apparatus with correspondingly small yields. Once the product is adequately suspended, however, further agitation is without significant effect. The partitioning of alkali ions during jarosite precipitation was ascertained for K:Na, Na:NH4, K:NH4, and K:Rb. Potassium jarosite is the most stable of the alkali jarosites and the stability falls systematically for lighter or heavier congeners; ammonium jarosite is slightly more stable than the sodium analogue. Complete solid solubility among the various alkali jarosite-type compounds was established.

Genome-wide comparative analysis of codon usage bias and codon context patterns among cyanobacterial genomes.

PubMed

Prabha, Ratna; Singh, Dhananjaya P; Sinha, Swati; Ahmad, Khurshid; Rai, Anil

2017-04-01

With the increasing accumulation of genomic sequence information of prokaryotes, the study of codon usage bias has gained renewed attention. The purpose of this study was to examine codon selection pattern within and across cyanobacterial species belonging to diverse taxonomic orders and habitats. We performed detailed comparative analysis of cyanobacterial genomes with respect to codon bias. Our analysis reflects that in cyanobacterial genomes, A- and/or T-ending codons were used predominantly in the genes whereas G- and/or C-ending codons were largely avoided. Variation in the codon context usage of cyanobacterial genes corresponded to the clustering of cyanobacteria as per their GC content. Analysis of codon adaptation index (CAI) and synonymous codon usage order (SCUO) revealed that majority of genes are associated with low codon bias. Codon selection pattern in cyanobacterial genomes reflected compositional constraints as major influencing factor. It is also identified that although, mutational constraint may play some role in affecting codon usage bias in cyanobacteria, compositional constraint in terms of genomic GC composition coupled with environmental factors affected codon selection pattern in cyanobacterial genomes. Copyright © 2016 Elsevier B.V. All rights reserved.

Berry ripening, pre-processing and thermal treatments affect the phenolic composition and antioxidant capacity of grape (Vitis vinifera L.) juice.

PubMed

Genova, Giuseppe; Tosetti, Roberta; Tonutti, Pietro

2016-01-30

Grape juice is an important dietary source of health-promoting antioxidant molecules. Different factors may affect juice composition and nutraceutical properties. The effects of some of these factors (harvest time, pre-processing ethylene treatment of grapes and juice thermal pasteurization) were here evaluated, considering in particular the phenolic composition and antioxidant capacity. Grapes (Vitis vinifera L., red-skinned variety Sangiovese) were collected twice in relation to the technological harvest (TH) and 12 days before TH (early harvest, EH) and treated with gaseous ethylene (1000 ppm) or air for 48 h. Fresh and pasteurized (78 °C for 30 min) juices were produced using a water bath. Three-way analysis of variance showed that the harvest date had the strongest impact on total polyphenols, hydroxycinnamates, flavonols, and especially on total flavonoids. Pre-processing ethylene treatment significantly increased the proanthocyanidin, anthocyanin and flavan-3-ol content in the juices. Pasteurization induced a significant increase in anthocyanin concentration. Antioxidant capacity was enhanced by ethylene treatment and pasteurization in juices from both TH and EH grapes. These results suggest that an appropriate management of grape harvesting date, postharvest and processing may lead to an improvement in nutraceutical quality of juices. Further research is needed to study the effect of the investigated factors on juice organoleptic properties. © 2015 Society of Chemical Industry.

[Distribution and Diversity of Ammonium-oxidizing Archaea and Ammonium-oxidizing Bacteria in Surface Sediments of Oujiang River].

PubMed

Li, Hu; Huang, Fu-yi; Su, Jian-qiang; Hong, You-wei; Yu, Shen

2015-12-01

Ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) play important roles in the biogeochemical nitrogen cycle. Rivers are important ecosystems containing a large number of functional microbes in nitrogen cycle. In this study, denaturing gradient gel electrophoresis (DGGE ) and real-time quantitative PCR (qPCR) technology were used to analyze the distribution and diversity of AOA and AOB in sediments from Oujiang. The results showed that the AOA community structure was similar among various sites, while the AOB community structure was significantly different, in which all detected AOB sequences were classified into Nitrosospira and Nitrosomonas, and 90% affiliated to Nitrosospira. The community composition of AOA was influenced by NH₄⁺ and TS, in addition, the AOB composition was affected by NH₄⁺, EC, pH, NO₃⁻, TC and TN. Total sulfur (TS) and electrical conductivity (EC) were the major factors influencing the diversity of AOA and AOB, respectively. AOA abundance was significantly higher than that of AOB. EC, NH₄⁺-N and NO₃⁻-N were the main environmental factors affecting the abundance of AOA and AOB. This study indicated that the community composition and diversity of AOA and AOB were significantly influenced by environmental factors, and AOA might be dominant drivers in the ammonia oxidation process in Oujiang surface sediment.

Repeated disturbances affect functional but not compositional resistance and resilience in an aquatic bacterioplankton community.

PubMed

Sjöstedt, Johanna; Langenheder, Silke; Kritzberg, Emma; Karlsson, Christofer M G; Lindström, Eva S

2018-05-07

Disturbances are believed to be one of the main factors influencing variations in community diversity and functioning. Here we investigated if exposure to a pH press disturbance affected the composition and functional performance of a bacterial community and its resistance, recovery and resilience to a second press disturbance (salt addition). Lake bacterial assemblages were initially exposed to reduced pH in six mesocosms whereas another six mesocosms were kept as reference. Seven days after the pH disturbance, three tanks from each treatment were exposed to a salt disturbance. Both bacterial production and enzyme activity were negatively affected by the salt treatment, regardless if the communities had been subject to a previous disturbance or not. However, cell-specific enzyme activity had a higher resistance in communities pre-exposed to the pH disturbance compared to the reference treatment. In contrast, for cell-specific bacterial production resistance was not affected, but recovery was faster in the communities that had previously been exposed to the pH disturbance. Over time, bacterial community composition diverged among treatments, in response to both pH and salinity. The difference in functional recovery, resilience and resistance may depend on differences in community composition caused by the pH disturbance, niche breadth or acquired stress resistance. This article is protected by copyright. All rights reserved. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

Pyrosequencing of Plaque Microflora In Twin Children with Discordant Caries Phenotypes

PubMed Central

Zhang, Meng; Chen, Yongxing; Xie, Lingzhi; Li, Yuhong; Jiang, Han; Du, Minquan

2015-01-01

Despite recent successes in the control of dental caries, the mechanism of caries development remains unclear. To investigate the causes of dental decay, especially in early childhood caries, the supragingival microflora composition of 20 twins with discordant caries phenotypes were analyzed using high-throughput pyrosequencing. In addition, the parents completed a lifestyle questionnaire. A total of 228,789 sequencing reads revealed 10 phyla, 84 genera, and 155 species of microflora, the relative abundances of these strains varied dramatically among the children, Comparative analysis between groups revealed that Veillonella, Corynebacterium and Actinomyces were presumed to be caries-related genera, Fusobacterium, Kingella and Leptotrichia were presumed to be healthy-related genus, yet this six genera were not statistically significant (P>0.05). Moreover, a cluster analysis revealed that the microbial composition of samples in the same group was often dissimilar but that the microbial composition observed in twins was usually similar. Although the genetic and environmental factors that strongly influence the microbial composition of dental caries remains unknown, we speculate that genetic factors primarily influence the individual's susceptibility to dental caries and that environmental factors primarily regulate the microbial composition of the dental plaque and the progression to caries. By using improved twins models and increased sample sizes, our study can be extended to analyze the specific genetic and environmental factors that affect the development of caries. PMID:26524687

Genetic principles

Treesearch

Ronald P. Overton; David T. Funk

1989-01-01

Tree growth is a function of both environment and genetic makeup. All forest management activities during a rotation from establishment to harvest affect the genetic composition and the environment of a stand. Silvicultural practices which fail to take both of these factors into account will reduce forest productivity.

Time-Dependent Behavior of a Graphite/Thermoplastic Composite and the Effects of Stress and Physical Aging

NASA Technical Reports Server (NTRS)

Gates, Thomas S.; Feldman, Mark

1995-01-01

Experimental studies were performed to determine the effects of stress and physical aging on the matrix dominated time dependent properties of IM7/8320 composite. Isothermal tensile creep/aging test techniques developed for polymers were adapted for testing of the composite material. Time dependent transverse and shear compliance's for an orthotropic plate were found from short term creep compliance measurements at constant, sub-T(8) temperatures. These compliance terms were shown to be affected by physical aging. Aging time shift factors and shift rates were found to be a function of temperature and applied stress.

The effect of membrane composition on the hemostatic balance.

PubMed

Smirnov, M D; Ford, D A; Esmon, C T; Esmon, N L

1999-03-23

The phospholipid composition requirements for optimal prothrombin activation and factor Va inactivation by activated protein C (APC) anticoagulant were examined. Vesicles composed of phosphatidylethanolamine (PE) and phosphatidylcholine (PC) supported factor Va inactivation relatively well. However, optimal factor Va inactivation still required relatively high concentrations of phosphatidylserine (PS). In addition, at a fixed concentration of phospholipid, PS, and APC, vesicles devoid of PE never attained a rate of factor Va inactivation achievable with vesicles containing PE. Polyunsaturation of any vesicle component also contributed significantly to APC inactivation of factor Va. Thus, PE makes an important contribution to factor Va inactivation that cannot be mimicked by PS. In the absence of polyunsaturation in the other membrane constituents, this contribution was dependent upon the presence of both the PE headgroup per se and unsaturation of the 1,2 fatty acids. Although PE did not affect prothrombin activation rates at optimal PS concentrations, PE reduced the requirement for PS approximately 10-fold. The Km(app) for prothrombin and the Kd(app) for factor Xa-factor Va decreased as a function of increasing PS concentration, reaching optimal values at 10-15% PS in the absence of PE but only 1% PS in the presence of PE. Fatty acid polyunsaturation had minimal effects. A lupus anticoagulant immunoglobulin was more inhibitory to both prothrombinase and factor Va inactivation in the presence of PE. The degree of inhibition of APC was significantly greater and much more dependent on the phospholipid composition than that of prothrombinase. Thus, subtle changes in the phospholipid composition of cells may control procoagulant and anticoagulant reactions differentially under both normal and pathological conditions.

Effect of Different Liners on Fracture Resistance of Premolars Restored with Conventional and Short Fiber-Reinforced Composite Resins.

PubMed

Shafiei, Fereshteh; Doozandeh, Maryam; Ghaffaripour, Dordaneh

2018-01-11

To see whether applying four different liners under short fiber-reinforced composite (SFRC), everX Posterior, compared to conventional composite resin, Z250, affected their strengthening property in premolar MOD cavities. Mesio-occluso-distal (MOD) cavities were prepared in 120 sound maxillary premolars divided into 10 groups (n = 12) in terms of two composite resin types and 4 liners or no liner. For each composite resin, in 5 groups no liner, resin-modified glass ionomer (RMGI), conventional flowable composite (COFL), self-adhesive flowable composite resin (SAFL), and self-adhesive resin cement (SARC) were applied prior to restoring incrementally. After water storage and thermocycling, static fracture resistance was tested. Data (in Newtons) were analyzed using two-way ANOVA (α = 0.05). Fracture resistance was significantly affected by composite resin type (p = 0.02), but not by the liner (p > 0.05). The interaction of the two factors was not statistically significant (p > 0.05). SFRC exhibited higher fracture strength (1470 ± 200 N) compared to conventional composite resin (1350 ± 290), irrespective of the application of liners. Application of SARC and SAFL liners led to a higher number of restorable fractures for both composite resins. The four liners can be used without interfering with the higher efficacy of SFRC, compared to conventional composite resins, to improve the fracture strength of premolar MOD cavities. © 2018 by the American College of Prosthodontists.

Psychometric properties of the Positive and Negative Affect Schedule (PANAS) in a heterogeneous sample of substance users.

PubMed

Serafini, Kelly; Malin-Mayor, Bo; Nich, Charla; Hunkele, Karen; Carroll, Kathleen M

2016-03-01

The Positive and Negative Affect Schedule (PANAS) is a widely used measure of affect. A comprehensive psychometric evaluation among substance users, however, has not been published. To examine the psychometric properties of the PANAS in a sample of outpatient treatment substance users. We used pooled data from four randomized clinical trials (N = 416; 34% female, 48% African American). A confirmatory factor analysis indicated adequate support for a two-factor correlated model comprised of Positive Affect and Negative Affect with correlated item errors (Comparative Fit Index = 0.93, Root Mean Square Error of Approximation = 0.07, χ(2) = 478.93, df = 156). Cronbach's α indicated excellent internal consistency for both factors (0.90 and 0.91, respectively). The PANAS factors had good convergence and discriminability (Composite Reliability > 0.7; Maximum Shared Variance < Average Variance Extracted). A comparison from baseline to Week 1 indicated acceptable test-retest reliability (Positive Affect = 0.80, Negative Affect = 0.76). Concurrent and discriminant validity were demonstrated with correlations with the Brief Symptom Inventory and Addiction Severity Index. The PANAS scores were also significantly correlated with treatment outcomes (e.g. Positive Affect was associated with the maximum days of consecutive abstinence from primary substance of abuse, r = 0.16, p = 0.001). Our data suggest that the psychometric properties of the PANAS are retained in substance using populations. Although several studies have focused on the role of Negative Affect, our findings suggest that Positive Affect may also be an important factor in substance use treatment outcomes.

Psychometric properties of the positive and negative affect schedule (PANAS) in a heterogeneous sample of substance users

PubMed Central

Serafini, Kelly; Malin-Mayor, Bo; Nich, Charla; Hunkele, Karen; Carroll, Kathleen M.

2016-01-01

Background The Positive and Negative Affect Schedule (PANAS) is a widely used measure of affect, and a comprehensive psychometric evaluation has never been conducted among substance users. Objective To examine the psychometric properties of the PANAS in a sample of outpatient treatment substance users. Methods We used pooled data from four randomized clinical trials (N = 416; 34% female, 48% African American). Results A confirmatory factor analysis indicated adequate support for a two-factor correlated model comprised of Positive Affect and Negative Affect with correlated item errors (Comparative Fit Index = .93, Root Mean Square Error of Approximation = .07, χ2 = 478.93, df = 156). Cronbach’s α indicated excellent internal consistency for both factors (.90 and .91, respectively). The PANAS factors had good convergence and discriminability (Composite Reliability >.7; Maximum Shared Variance < Average Variance Extracted). A comparison from baseline to Week 1 indicated acceptable test-retest reliability (Positive Affect = .80, Negative Affect = .76). Concurrent and discriminant validity were demonstrated with correlations with the Brief Symptom Inventory and Addiction Severity Index. The PANAS scores were also significantly correlated with treatment outcomes (e.g., Positive Affect was associated with the maximum days of consecutive abstinence from primary substance of abuse, r = .16, p = .001). Conclusion Our data suggest that the psychometric properties of the PANAS are retained in substance using populations. Although several studies have focused on the role of Negative Affect, our findings suggest that Positive Affect may also be an important factor in substance use treatment outcomes. PMID:26905228

Environmental conditions regulate the impact of plants on cloud formation

PubMed Central

Zhao, D. F.; Buchholz, A.; Tillmann, R.; Kleist, E.; Wu, C.; Rubach, F.; Kiendler-Scharr, A.; Rudich, Y.; Wildt, J.; Mentel, Th. F.

2017-01-01

The terrestrial vegetation emits large amounts of volatile organic compounds (VOC) into the atmosphere, which on oxidation produce secondary organic aerosol (SOA). By acting as cloud condensation nuclei (CCN), SOA influences cloud formation and climate. In a warming climate, changes in environmental factors can cause stresses to plants, inducing changes of the emitted VOC. These can modify particle size and composition. Here we report how induced emissions eventually affect CCN activity of SOA, a key parameter in cloud formation. For boreal forest tree species, insect infestation by aphids causes additional VOC emissions which modifies SOA composition thus hygroscopicity and CCN activity. Moderate heat increases the total amount of constitutive VOC, which has a minor effect on hygroscopicity, but affects CCN activity by increasing the particles' size. The coupling of plant stresses, VOC composition and CCN activity points to an important impact of induced plant emissions on cloud formation and climate. PMID:28218253

Environmental conditions regulate the impact of plants on cloud formation.

PubMed

Zhao, D F; Buchholz, A; Tillmann, R; Kleist, E; Wu, C; Rubach, F; Kiendler-Scharr, A; Rudich, Y; Wildt, J; Mentel, Th F

2017-02-20

The terrestrial vegetation emits large amounts of volatile organic compounds (VOC) into the atmosphere, which on oxidation produce secondary organic aerosol (SOA). By acting as cloud condensation nuclei (CCN), SOA influences cloud formation and climate. In a warming climate, changes in environmental factors can cause stresses to plants, inducing changes of the emitted VOC. These can modify particle size and composition. Here we report how induced emissions eventually affect CCN activity of SOA, a key parameter in cloud formation. For boreal forest tree species, insect infestation by aphids causes additional VOC emissions which modifies SOA composition thus hygroscopicity and CCN activity. Moderate heat increases the total amount of constitutive VOC, which has a minor effect on hygroscopicity, but affects CCN activity by increasing the particles' size. The coupling of plant stresses, VOC composition and CCN activity points to an important impact of induced plant emissions on cloud formation and climate.

Links between Dietary Protein Sources, the Gut Microbiota, and Obesity.

PubMed

Madsen, Lise; Myrmel, Lene S; Fjære, Even; Liaset, Bjørn; Kristiansen, Karsten

2017-01-01

The association between the gut microbiota and obesity is well documented in both humans and in animal models. It is also demonstrated that dietary factors can change the gut microbiota composition and obesity development. However, knowledge of how diet, metabolism and gut microbiota mutually interact and modulate energy metabolism and obesity development is still limited. Epidemiological studies indicate an association between intake of certain dietary protein sources and obesity. Animal studies confirm that different protein sources vary in their ability to either prevent or induce obesity. Different sources of protein such as beans, vegetables, dairy, seafood, and meat differ in amino acid composition. Further, the type and level of other factors, such as fatty acids and persistent organic pollutants (POPs) vary between dietary protein sources. All these factors can modulate the composition of the gut microbiota and may thereby influence their obesogenic properties. This review summarizes evidence of how different protein sources affect energy efficiency, obesity development, and the gut microbiota, linking protein-dependent changes in the gut microbiota with obesity.

Links between Dietary Protein Sources, the Gut Microbiota, and Obesity

PubMed Central

Madsen, Lise; Myrmel, Lene S.; Fjære, Even; Liaset, Bjørn; Kristiansen, Karsten

2017-01-01

The association between the gut microbiota and obesity is well documented in both humans and in animal models. It is also demonstrated that dietary factors can change the gut microbiota composition and obesity development. However, knowledge of how diet, metabolism and gut microbiota mutually interact and modulate energy metabolism and obesity development is still limited. Epidemiological studies indicate an association between intake of certain dietary protein sources and obesity. Animal studies confirm that different protein sources vary in their ability to either prevent or induce obesity. Different sources of protein such as beans, vegetables, dairy, seafood, and meat differ in amino acid composition. Further, the type and level of other factors, such as fatty acids and persistent organic pollutants (POPs) vary between dietary protein sources. All these factors can modulate the composition of the gut microbiota and may thereby influence their obesogenic properties. This review summarizes evidence of how different protein sources affect energy efficiency, obesity development, and the gut microbiota, linking protein-dependent changes in the gut microbiota with obesity. PMID:29311977

IMPACT OF SEX COMPOSITION OF LIVING CHILDREN AND COUPLES' AGREEMENT ON SUBSEQUENT FERTILITY IN INDIA.

PubMed

Kastor, Anshul; Chatterjee, Sayantani

2017-11-23

The desire for children could be considered a reliable predictor of subsequent fertility. At the same time, the sex composition of surviving children, along with other demographic and socioeconomic factors, may affect a couple's fertility desire and, therefore, their subsequent fertility. This study examined the impact of the sex composition of living children and a couple's agreement on fertility desire on their subsequent fertility in India using data came from two rounds of nationally representative surveys: the India Human Development Survey (IHDS)-I (2004-05) and IHDS-II (2011-12). To understand which factors affect the chances of an additional pregnancy or childbirth, a random effects logistic regression model was applied to the panel data. It was found that the fertility desires of both marital partners were important in determining the chances of subsequent fertility. About 35% of the couples wanting to limit children had undergone pregnancy or childbirth, while 76% of the couples wanting more children had conceived or given birth to children. In the case of discordance between the spouses, subsequent fertility was found to remain intermediate between those agreeing to continue childbirth and those wanting to limit it. The findings also affirmed that child sex preference, specifically son preference, still persists in Indian society. More than 80% of the couples with only daughters in IHDS-I mutually wanted to have additional children, whereas in families that only had sons, the chance of a subsequent pregnancy was inversely associated with the number of sons. Strong patriarchal settings, combined with cultural and socioeconomic factors, affect the persistence of sex preference in India. Programmes aimed at increasing family planning use need to address son preference and should include components that promote the value of girl children.

Cardiovascular and Antiobesity Effects of Resveratrol Mediated through the Gut Microbiota.

PubMed

Bird, Julia K; Raederstorff, Daniel; Weber, Peter; Steinert, Robert E

2017-11-01

Encouraging scientific research into the health effects of dietary bioactive resveratrol has been confounded by its rapid first-pass metabolism, which leads to low in vivo bioavailability. Preliminary studies have shown that resveratrol can modulate gut microbiota composition, undergo biotransformation to active metabolites via the intestinal microbiota, or affect gut barrier function. In rodents, resveratrol can modify the relative Bacteroidetes:Firmicutes ratio and reverse the gut microbial dysbiosis caused by a high-fat diet. By upregulating the expression of genes involved in maintaining tight junctions between intestinal cells, resveratrol contributes to gut barrier integrity. The composition of the gut microbiome and rapid metabolism of resveratrol determines the production of resveratrol metabolites, which are found at greater concentrations in humans after ingestion than their parent molecule and can have similar biological effects. Resveratrol may affect cardiovascular risk factors such as elevated blood cholesterol or trimethylamine N -oxide concentrations. Modulating the composition of the gut microbiota by resveratrol may affect central energy metabolism and modify concentrations of satiety hormones to produce antiobesity effects. Encouraging research from animal models could be tested in humans. © 2017 American Society for Nutrition.

Relationships among plants, soils and microbial communities along a hydrological gradient in the New Jersey Pinelands, USA

PubMed Central

Yu, Shen; Ehrenfeld, Joan G.

2010-01-01

Background and Aims Understanding the role of different components of hydrology in structuring wetland communities is not well developed. A sequence of adjacent wetlands located on a catenary sequence of soils and receiving the same sources and qualities of water is used to examine specifically the role of water-table median position and variability in affecting plant and microbial community composition and soil properties. Methods Two replicates of three types of wetland found adjacent to each other along a hydrological gradient in the New Jersey Pinelands (USA) were studied. Plant-community and water-table data were obtained within a 100-m2 plot in each community (pine swamp, maple swamp and Atlantic-white-cedar swamp). Monthly soil samples from each plot were analysed for soil moisture, organic matter, extractable nitrogen fractions, N mineralization rate and microbial community composition. Multivariate ordination methods were used to compare patterns among sites within and between data sets. Key Results The maple and pine wetlands were more similar to each other in plant community composition, soil properties and microbial community composition than either was to the cedar swamps. However, maple and pine wetlands differed from each other in water-table descriptors as much as they differed from the cedar swamps. All microbial communities were dominated by Gram-positive bacteria despite hydrologic differences among the sites. Water-table variability was as important as water-table level in affecting microbial communities. Conclusions Water tables affect wetland communities through both median level and variability. Differentiation of both plant and microbial communities are not simple transforms of differences in water-table position, even when other hydrologic factors are kept constant. Rather, soil genesis, a result of both water-table position and geologic history, appears to be the main factor affecting plant and microbial community similarities. PMID:19643908

Analysis of factors driving stream water composition and synthesis of management tools--a case study on small/medium Greek catchments.

PubMed

Skoulikidis, N Th; Amaxidis, Y; Bertahas, I; Laschou, S; Gritzalis, K

2006-06-01

Twenty-nine small- and mid-sized permanent rivers (thirty-six sites) scattered throughout Greece and equally distributed within three geo-chemical-climatic zones, have been investigated in a seasonal base. Hydrochemical types have been determined and spatio-temporal variations have been interpreted in relation to environmental characteristics and anthropogenic pressures. Multivariate statistical techniques have been used to identify the factors and processes affecting hydrochemical variability and the driving forces that control aquatic composition. It has been shown that spatial variation of aquatic quality is mainly governed by geological and hydrogeological factors. Due to geological and climatic variability, the three zones have different hydrochemical characteristics. Temporal hydrological variations in combination with hydrogeological factors control seasonal hydrochemical trends. Respiration processes due to municipal wastewaters, dominate in summer, and enhance nutrient, chloride and sodium concentrations, while nitrate originates primarily from agriculture. Photosynthetic processes dominate in spring. Carbonate chemistry is controlled by hydrogeological factors and biological activity. A possible enrichment of surface waters with nutrients in "pristine" forested catchments is attributed to soil leaching and mineralisation processes. Two management tools have been developed: a nutrient classification system and a rapid prediction of aquatic composition tool.

Wood Composite Adhesives

NASA Astrophysics Data System (ADS)

Gomez-Bueso, Jose; Haupt, Robert

The global environment, in which phenolic resins are being used for wood composite manufacture, has changed significantly during the last decade. This chapter reviews trends that are driving the use and consumption of phenolic resins around the world. The review begins with recent data on volume usage and regional trends, followed by an analysis of factors affecting global markets. In a section on environmental factors, the impact of recent formaldehyde emission regulations is discussed. The section on economics introduces wood composite production as it relates to the available adhesive systems, with special emphasis on the technical requirement to improve phenolic reactivity. Advances in composite process technology are introduced, especially in regard to the increased demands the improvements place upon adhesive system performance. The specific requirements for the various wood composite families are considered in the context of adhesive performance needs. The results of research into current chemistries are discussed, with a review of recent findings regarding the mechanisms of phenolic condensation and acceleration. Also, the work regarding alternate natural materials, such as carbohydrates, lignins, tannins, and proteinaceous materials, is presented. Finally, new developments in alternative adhesive technologies are reported.

Household waste compositional analysis variation from insular communities in the framework of waste prevention strategy plans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zorpas, Antonis A., E-mail: antonis.zorpas@ouc.ac.cy; Lasaridi, Katia, E-mail: klasaridi@hua.gr; Voukkali, Irene

Highlights: • Waste framework directive has set clear waste prevention procedures. • Household Compositional analysis. • Waste management plans. • Zero waste approach. • Waste generation. - Abstract: Waste management planning requires reliable data regarding waste generation, affecting factors on waste generation and forecasts of waste quantities based on facts. In order to decrease the environmental impacts of waste management the choice of prevention plan as well as the treatment method must be based on the features of the waste that are produced in a specific area. Factors such as culture, economic development, climate, and energy sources have an impactmore » on waste composition; composition influences the need of collecting waste more or less frequently of waste collection and disposition. The research question was to discover the main barriers concerning the compositional analysis in Insular Communities under warm climate conditions and the findings from this study enabled the main contents of a waste management plan to be established. These included advice to residents on waste minimisation, liaison with stakeholders and the expansion of kerbside recycling schemes.« less

Internal and external factors affecting photosynthetic pigment composition in plants: a meta-analytical approach.

PubMed

Esteban, Raquel; Barrutia, Oihana; Artetxe, Unai; Fernández-Marín, Beatriz; Hernández, Antonio; García-Plazaola, José Ignacio

2015-04-01

Photosynthetic pigment composition has been a major study target in plant ecophysiology during the last three decades. Although more than 2000 papers have been published, a comprehensive evaluation of the responses of photosynthetic pigment composition to environmental conditions is not yet available. After an extensive survey, we compiled data from 525 papers including 809 species (subkingdom Viridiplantae) in which pigment composition was described. A meta-analysis was then conducted to assess the ranges of photosynthetic pigment content. Calculated frequency distributions of pigments were compared with those expected from the theoretical pigment composition. Responses to environmental factors were also analysed. The results revealed that lutein and xanthophyll cycle pigments (VAZ) were highly responsive to the environment, emphasizing the high phenotypic plasticity of VAZ, whereas neoxanthin was very stable. The present meta-analysis supports the existence of relatively narrow limits for pigment ratios and also supports the presence of a pool of free 'unbound' VAZ. Results from this study provide highly reliable ranges of photosynthetic pigment contents as a framework for future research on plant pigments. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

EFL Teachers' Responses to L2 Writing.

ERIC Educational Resources Information Center

Chang, Yuh-Fang

This study investigated differences in the product and process of evaluating second language compositions by Taiwanese speakers of English. It examined whether such factors as language background (native English speaker versus native Chinese speaker), academic discipline, and educational background affected raters' scoring outcomes; whether rating…

Household waste compositional analysis variation from insular communities in the framework of waste prevention strategy plans.

PubMed

Zorpas, Antonis A; Lasaridi, Katia; Voukkali, Irene; Loizia, Pantelitsa; Chroni, Christina

2015-04-01

Waste management planning requires reliable data regarding waste generation, affecting factors on waste generation and forecasts of waste quantities based on facts. In order to decrease the environmental impacts of waste management the choice of prevention plan as well as the treatment method must be based on the features of the waste that are produced in a specific area. Factors such as culture, economic development, climate, and energy sources have an impact on waste composition; composition influences the need of collecting waste more or less frequently of waste collection and disposition. The research question was to discover the main barriers concerning the compositional analysis in Insular Communities under warm climate conditions and the findings from this study enabled the main contents of a waste management plan to be established. These included advice to residents on waste minimisation, liaison with stakeholders and the expansion of kerbside recycling schemes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of water flow and chemical environment on microbiota growth and composition in the human colon.

PubMed

Cremer, Jonas; Arnoldini, Markus; Hwa, Terence

2017-06-20

The human gut harbors a dynamic microbial community whose composition bears great importance for the health of the host. Here, we investigate how colonic physiology impacts bacterial growth, which ultimately dictates microbiota composition. Combining measurements of bacterial physiology with analysis of published data on human physiology into a quantitative, comprehensive modeling framework, we show how water flow in the colon, in concert with other physiological factors, determine the abundances of the major bacterial phyla. Mechanistically, our model shows that local pH values in the lumen, which differentially affect the growth of different bacteria, drive changes in microbiota composition. It identifies key factors influencing the delicate regulation of colonic pH, including epithelial water absorption, nutrient inflow, and luminal buffering capacity, and generates testable predictions on their effects. Our findings show that a predictive and mechanistic understanding of microbial ecology in the gut is possible. Such predictive understanding is needed for the rational design of intervention strategies to actively control the microbiota.

Effect of genetic and phenotypic factors on the composition of commercial marmande type tomatoes studied through HRMAS NMR spectroscopy.

PubMed

Iglesias, María José; García López, Jesús; Collados Luján, Juan Fernando; López Ortiz, Fernando; Bojórquez Pereznieto, Humberto; Toresano, Fernando; Camacho, Francisco

2014-01-01

The effects of genetic, technological and environmental factors on the chemical composition of four marmande type tomato varieties have been investigated. The study is based on the analysis of (1)H HRMAS NMR spectra of tomato purée using a combination of partial least squares (PLS) and assigned signal analysis (ASA). In agreement with genetic, morphological and taste characteristics of the tomatoes studied, the analysis of the NMR data allows two groups of samples to be differentiated. The type of culture and climatic conditions can reduce the compositional differences. The extension of the compositional changes produced by climatic conditions is variety-depend. Neither grafting nor perlite affect significantly the relative content of primary metabolites. This was not the case for tomatoes grown using the pure hydroponic production system based on the recirculation of nutrient solution, New Growing System NGS®, which seems to be an effective agricultural approach to improve tomato quality. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of water flow and chemical environment on microbiota growth and composition in the human colon

PubMed Central

Cremer, Jonas; Arnoldini, Markus; Hwa, Terence

2017-01-01

The human gut harbors a dynamic microbial community whose composition bears great importance for the health of the host. Here, we investigate how colonic physiology impacts bacterial growth, which ultimately dictates microbiota composition. Combining measurements of bacterial physiology with analysis of published data on human physiology into a quantitative, comprehensive modeling framework, we show how water flow in the colon, in concert with other physiological factors, determine the abundances of the major bacterial phyla. Mechanistically, our model shows that local pH values in the lumen, which differentially affect the growth of different bacteria, drive changes in microbiota composition. It identifies key factors influencing the delicate regulation of colonic pH, including epithelial water absorption, nutrient inflow, and luminal buffering capacity, and generates testable predictions on their effects. Our findings show that a predictive and mechanistic understanding of microbial ecology in the gut is possible. Such predictive understanding is needed for the rational design of intervention strategies to actively control the microbiota. PMID:28588144

Durable bonds at the adhesive/dentin interface: an impossible mission or simply a moving target?

PubMed Central

SPENCER, Paulette; Jonggu PARK, Qiang YE; MISRA, Anil; BOHATY, Brenda S.; SINGH, Viraj; PARTHASARATHY, Ranga; SENE, Fábio; de Paiva GONÇALVES, Sérgio Eduardo; LAURENCE, Jennifer

2013-01-01

Composite restorations have higher failure rates, more recurrent caries and increased frequency of replacement as compared to dental amalgam. Penetration of bacterial enzymes, oral fluids, and bacteria into the crevices between the tooth and composite undermines the restoration and leads to recurrent decay and failure. The gingival margin of composite restora tions is particularly vulnerable to decay and at this margin, the adhesive and its seal to dentin provides the primary barrier between the prepared tooth and the environment. The intent of this article is to examine physico-chemical factors that affect the integrity and durability of the adhesive/dentin interfacial bond; and to explore how these factors act synergistically with mechanical forces to undermine the composite restoration. The article will examine the various avenues that have been pursued to address these problems and it will explore how alterations in material chemistry could address the detrimental impact of physico-chemical stresses on the bond formed at the adhesive/dentin interface. PMID:24855586

Influence of Finishing and Polishing Techniques and Abrasion on Transmittance and Roughness of Composite Resins.

PubMed

Carneiro, Pma; Ramos, T M; de Azevedo, C S; de Lima, E; de Souza, Shj; Turbino, M L; Cesar, P F; Matos, A B

The aim of this study was to evaluate the influence of finishing and polishing systems and toothbrush abrasion on transmittance (T) and surface roughness (Ra) of three composite resins (Filtek Z350 XT, Tetric N-Ceram, and IPS Empress Direct). Eighteen resin disks (10 mm diameter × 2 mm thick) finished by polyester strips had initial surface smoothness recorded, representing phase 1 (P1). Specimens were divided into three groups (n=6) according to the finishing/polishing instrument used (OneGloss, TopGloss, and Sof-Lex) to compose phase 2 samples (P2). Then specimens were subjected to 514 cycles of toothbrush simulation using a toothpaste slurry, with a constant load applied to soft bristles, and were then washed (phase 3=P3). After each phase, the specimens were examined by an optical profiler and spectrophotometer to measure Ra and T. Data were analyzed by analysis of variance, Tukey and Pearson tests. T values were statistically influenced by composite resin ( p=0.000) and phase of measurement ( p=0.000) factors, while the finishing/polishing system used ( p=0.741) did not affect T. On the other hand, Ra values were statistically affected by the factor finishing/polishing system ( p=0.000), but not by composite resin ( p=0.100) and phase of measurement ( p=0.451). Tetric N-Ceram and Empress Direct presented higher values of roughness when polished by OneGloss, while TopGloss and Sof-Lex showed a lower roughness. It can be concluded that composite resins transmitted more light after dental abrasion. Transmittance of composite resins was not modified by the distinct roughness created by finishing/polishing instruments.

Influence of Layup Sequence on the Surface Accuracy of Carbon Fiber Composite Space Mirrors

NASA Astrophysics Data System (ADS)

Yang, Zhiyong; Liu, Qingnian; Zhang, Boming; Xu, Liang; Tang, Zhanwen; Xie, Yongjie

2018-04-01

Layup sequence is directly related to stiffness and deformation resistance of the composite space mirror, and error caused by layup sequence can affect the surface precision of composite mirrors evidently. Variation of layup sequence with the same total thickness of composite space mirror changes surface form of the composite mirror, which is the focus of our study. In our research, the influence of varied quasi-isotropic stacking sequences and random angular deviation on the surface accuracy of composite space mirrors was investigated through finite element analyses (FEA). We established a simulation model for the studied concave mirror with 500 mm diameter, essential factors of layup sequences and random angular deviations on different plies were discussed. Five guiding findings were described in this study. Increasing total plies, optimizing stacking sequence and keeping consistency of ply alignment in ply placement are effective to improve surface accuracy of composite mirror.

A Prospective Metagenomic and Metabolomic Analysis of the Impact of Exercise and/or Whey Protein Supplementation on the Gut Microbiome of Sedentary Adults.

PubMed

Cronin, Owen; Barton, Wiley; Skuse, Peter; Penney, Nicholas C; Garcia-Perez, Isabel; Murphy, Eileen F; Woods, Trevor; Nugent, Helena; Fanning, Aine; Melgar, Silvia; Falvey, Eanna C; Holmes, Elaine; Cotter, Paul D; O'Sullivan, Orla; Molloy, Michael G; Shanahan, Fergus

2018-01-01

Many components of modern living exert influence on the resident intestinal microbiota of humans with resultant impact on host health. For example, exercise-associated changes in the diversity, composition, and functional profiles of microbial populations in the gut have been described in cross-sectional studies of habitual athletes. However, this relationship is also affected by changes in diet, such as changes in dietary and supplementary protein consumption, that coincide with exercise. To determine whether increasing physical activity and/or increased protein intake modulates gut microbial composition and function, we prospectively challenged healthy but sedentary adults with a short-term exercise regime, with and without concurrent daily whey protein consumption. Metagenomics- and metabolomics-based assessments demonstrated modest changes in gut microbial composition and function following increases in physical activity. Significant changes in the diversity of the gut virome were evident in participants receiving daily whey protein supplementation. Results indicate that improved body composition with exercise is not dependent on major changes in the diversity of microbial populations in the gut. The diverse microbial characteristics previously observed in long-term habitual athletes may be a later response to exercise and fitness improvement. IMPORTANCE The gut microbiota of humans is a critical component of functional development and subsequent health. It is important to understand the lifestyle and dietary factors that affect the gut microbiome and what impact these factors may have. Animal studies suggest that exercise can directly affect the gut microbiota, and elite athletes demonstrate unique beneficial and diverse gut microbiome characteristics. These characteristics are associated with levels of protein consumption and levels of physical activity. The results of this study show that increasing the fitness levels of physically inactive humans leads to modest but detectable changes in gut microbiota characteristics. For the first time, we show that regular whey protein intake leads to significant alterations to the composition of the gut virome.

Spatiotemporal microbiota dynamics from quantitative in vitro and in silico models of the gut

NASA Astrophysics Data System (ADS)

Hwa, Terence

The human gut harbors a dynamic microbial community whose composition bears great importance for the health of the host. Here, we investigate how colonic physiology impacts bacterial growth behaviors, which ultimately dictate the gut microbiota composition. Combining measurements of bacterial growth physiology with analysis of published data on human physiology into a quantitative modeling framework, we show how hydrodynamic forces in the colon, in concert with other physiological factors, determine the abundances of the major bacterial phyla in the gut. Our model quantitatively explains the observed variation of microbiota composition among healthy adults, and predicts colonic water absorption (manifested as stool consistency) and nutrient intake to be two key factors determining this composition. The model further reveals that both factors, which have been identified in recent correlative studies, exert their effects through the same mechanism: changes in colonic pH that differentially affect the growth of different bacteria. Our findings show that a predictive and mechanistic understanding of microbial ecology in the human gut is possible, and offer the hope for the rational design of intervention strategies to actively control the microbiota. This work is supported by the Bill and Melinda Gates Foundation.

[Effect of variation of lemon intake and walking in daily life on various indicators of muscle mass and blood biochemistry in menopausal middle-aged and elderly women].

PubMed

Sato, Kimiko; Domoto, Tokio; Hiramitsu, Masanori; Katagiri, Takao; Kato, Yoji; Miyake, Yukiko; Ishihara, Katsuhide; Umei, Namiko; Takigawa, Atsushi; Harada, Toshihide; Aoi, Satomi; Ikeda, Hiromi

2014-01-01

We examined the factors considered to change body composition and blood biochemistry indicators in menopausal middle-aged and elderly women. These changes result from exercise by walking as part of their daily activities and lemon consumption by women who live on the small islands of the Seto Inland Sea, Japan's largest citrus fruit (lemon)-producing region. Between September 2011 and March 2012, we recorded the daily lemon consumption and the number of steps taken by 101 middle-aged and elderly female lemon farmers. We also measured their body dimensions, body compositions, and blood pressure pulse wave velocity and conducted blood tests before and after the survey period. The results before and after the survey period were compared by the t-test and associations were determined on the basis of Pearson's correlation coefficient. Covariance structural analysis was carried out to determine causal associations. From the results of covariance structure analysis, lemon intake did not have a direct impact on each item examined. The third item, i.e., "the factors related to arteriosclerosis," was affected indirectly via citric acid and fatigue, and anticoagulation was shown. The fourth item, i.e., "the factors related to maintenance of muscle mass," which is affected by menopausal years and the change in walking speed, was shown to be associated with the second item, i.e., "the factors related to lipid metabolism." Menopausal years affected the first, third and fourth items. Lemon intake did not have a direct impact on each item. Lemon has been shown to indirectly affect the third item through citric acid. Walking affected the second item, the level of total cholesterol, such as HDL cholesterol, through the fourth item. The importance of providing services that lead to sustained physical activity and a well-balanced metabolism between lipids and carbohydrates has been shown.

Estimating the effect of fermentation yeast on distillers grains protein

USDA-ARS?s Scientific Manuscript database

Distillers dried grains with solubles (DDGS) is the key co-product of bio-ethanol production from grains. Major factors affecting its quality and market values include protein quantity (concentration) and quality (amino acid composition). Yet, the effect of fermentation yeast on DDGS quality has no...

LAND-COVER CHARACTERIZATION AND CHANGE DETECTION USING MULTI-TEMPORAL MODIS NDIV DATA

EPA Science Inventory

Land-cover (LC) composition and conversions are important factors that affect ecosystem condition and function. These data are frequently used as a primary data source to generate landscape-based metrics to assess landscape condition at multiple assessment scales. The use of sate...

Salinity affects compositional traits of epibacterial communities on the brown macroalga Fucus vesiculosus.

PubMed

Stratil, Stephanie B; Neulinger, Sven C; Knecht, Henrik; Friedrichs, Anette K; Wahl, Martin

2014-05-01

Epibiotic biofilms have the potential to control major aspects of the biology and ecology of their hosts. Their composition and function may thus be essential for the health of the host. We tested the influence of salinity on the composition of epibacterial communities associated with the brown macroalga Fucus vesiculosus. Algal individuals were incubated at three salinities (5, 19, and 25) for 14 days and nonliving reference substrata (stones) were included in the experiment. Subsequently, the composition of their surface-associated bacterial communities was analyzed by 454 pyrosequencing of 16S rRNA gene sequences. Redundancy analysis revealed that the composition of epiphytic and epilithic communities significantly differed and were both affected by salinity. We found that 5% of 2494 epiphytic operational taxonomic units at 97% sequence similarity were responsible for the observed shifts. Epibacterial α-diversity was significantly lower at salinity 5 but did not differ between substrata. Our results indicate that salinity is an important factor in structuring alga-associated epibacterial communities with respect to composition and/or diversity. Whether direct or indirect mechanisms (via altered biotic interactions) may have been responsible for the observed shifts is discussed. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Degradation prediction model and stem cell growth of gelatin-PEG composite hydrogel.

PubMed

Zhou, Nan; Liu, Chang; Lv, Shijie; Sun, Dongsheng; Qiao, Qinglong; Zhang, Rui; Liu, Yang; Xiao, Jing; Sun, Guangwei

2016-12-01

Gelatin hydrogel has great potential in regenerative medicine. The degradation of gelatin hydrogel is important to control the release profile of encapsulated biomolecules and regulate in vivo tissue repair process. As a plasticizer, PEG can significantly improve the mechanical property of gelatin hydrogel. However, how preparation parameters affect the degradation rate of gelatin-PEG composite hydrogel is still not clear. In this study, the significant effect factor, glutaraldehyde (GA) concentration, was confirmed by means of Plackett-Burman method. Then a mathematical model was built to predict the degradation rate of composite hydrogels under different preparation conditions using the response surface method (RSM), which was helpful to prepare the certain composite hydrogel with desired degradation rate. In addition, it was found that gelatin-PEG composite hydrogel surface well supported the adhesion and growth of human mesenchymal stem cells (MSCs). Moreover, PEG concentration not only could adjust hydrogel degradation more subtly, but also might increase the cross-linking degree and affect the cell migration. Therefore, these results would be useful to optimize the preparation of gelatin-PEG composite hydrogel for drug delivery or tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 3149-3156, 2016. © 2016 Wiley Periodicals, Inc.

Litter type affects the activity of aerobic decomposers in a boreal peatland more than site nutrient and water level regimes

NASA Astrophysics Data System (ADS)

Straková, P.; Niemi, R. M.; Freeman, C.; Peltoniemi, K.; Toberman, H.; Heiskanen, I.; Fritze, H.; Laiho, R.

2011-02-01

Peatlands are carbon (C) storage ecosystems sustained by a high water level (WL). High WL creates anoxic conditions that suppress the activity of aerobic decomposers and provide conditions for peat accumulation. Peatland function can be dramatically affected by WL drawdown caused by land-use and/or climate change. Aerobic decomposers are directly affected by WL drawdown through environmental factors such as increased oxygenation and nutrient availability. Additionally, they are indirectly affected via changes in plant community composition and litter quality. We studied the relative importance of direct and indirect effects of WL drawdown on aerobic decomposer activity in plant litter. We did this by profiling 11 extracellular enzymes involved in the mineralization of organic C, nitrogen, phosphorus and sulphur. Our study sites represented a three-stage chronosequence from pristine (undrained) to short-term (years) and long-term (decades) WL drawdown conditions under two nutrient regimes. The litter types included reflected the prevalent vegetation, i.e., Sphagnum mosses, graminoids, shrubs and trees. WL drawdown had a direct and positive effect on microbial activity. Enzyme allocation shifted towards C acquisition, which caused an increase in the rate of decomposition. However, litter type overruled the direct effects of WL drawdown and was the main factor shaping microbial activity patterns. Our results imply that changes in plant community composition in response to persistent WL drawdown will strongly affect the C dynamics of peatlands.

[Effects of global change on soil fauna diversity: A review].

PubMed

Wu, Ting-Juan

2013-02-01

Terrestrial ecosystem consists of aboveground and belowground components, whose interaction affects the ecosystem processes and functions. Soil fauna plays an important role in biogeochemical cycles. With the recognizing of the significance of soil fauna in ecosystem processes, increasing evidences demonstrated that global change has profound effects on soil faunima diversity. The alternation of land use type, the increasing temperature, and the changes in precipitation pattern can directly affect soil fauna diversity, while the increase of atmospheric CO2 concentration and nitrogen deposition can indirectly affect the soil fauna diversity by altering plant community composition, diversity, and nutrient contents. The interactions of different environmental factors can co-affect the soil fauna diversity. To understand the effects of different driving factors on soil fauna diversity under the background of climate change would facilitate us better predicting how the soil fauna diversity and related ecological processes changed in the future.

Effect of quantity and composition of waste on the prediction of annual methane potential from landfills.

PubMed

Cho, Han Sang; Moon, Hee Sun; Kim, Jae Young

2012-04-01

A study was conducted to investigate the effect of waste composition change on the methane production in landfills. An empirical equation for the methane potential of the mixed waste is derived based on the methane potential values of individual waste components and the compositional ratio of waste components. A correction factor was introduced in the equation and was determined from the BMP and lysimeter tests. The equation and LandGEM were applied for a full size landfill and the annual methane potential was estimated. Results showed that the changes in quantity of waste affected the annual methane potential from the landfill more than the changes of waste composition. Copyright © 2012 Elsevier Ltd. All rights reserved.

Risks and reliability of manufacturing processes as related to composite materials for spacecraft structures

NASA Technical Reports Server (NTRS)

Bao, Han P.

1995-01-01

Fabricating primary aircraft and spacecraft structures using advanced composite materials entail both benefits and risks. The benefits come from much improved strength-to-weight ratios and stiffness-to-weight ratios, potential for less part count, ability to tailor properties, chemical and solvent resistance, and superior thermal properties. On the other hand, the risks involved include high material costs, lack of processing experience, expensive labor, poor reproducibility, high toxicity for some composites, and a variety of space induced risks. The purpose of this project is to generate a manufacturing database for a selected number of materials with potential for space applications, and to rely on this database to develop quantitative approaches to screen candidate materials and processes for space applications on the basis of their manufacturing risks including costs. So far, the following materials have been included in the database: epoxies, polycyanates, bismalemides, PMR-15, polyphenylene sulfides, polyetherimides, polyetheretherketone, and aluminum lithium. The first four materials are thermoset composites; the next three are thermoplastic composites, and the last one is is a metal. The emphasis of this database is on factors affecting manufacturing such as cost of raw material, handling aspects which include working life and shelf life of resins, process temperature, chemical/solvent resistance, moisture resistance, damage tolerance, toxicity, outgassing, thermal cycling, and void content, nature or type of process, associate tooling, and in-process quality assurance. Based on industry experience and published literature, a relative ranking was established for each of the factors affecting manufacturing as listed above. Potential applications of this database include the determination of a delta cost factor for specific structures with a given process plan and a general methodology to screen materials and processes for incorporation into the current conceptual design optimization of future spacecrafts as being coordinated by the Vehicle Analysis Branch where this research is being conducted.

Malnutrition and ageing

PubMed Central

Hickson, M

2006-01-01

This article aims to provide an overview of the problems that exist in relation to malnutrition and the elderly population. The changes that occur in body composition during ageing are described and how this may affect disease risk. The possible metabolic processes behind weight loss are discussed and the numerous factors that affect nutritional status in the older age group are described. Prevention of malnutrition in this group is important and so the roles of nutrition screening and assessment are examined. PMID:16397072

Women in the Legal Profession: A Progress Report.

ERIC Educational Resources Information Center

Fossum, Donna

1981-01-01

The modern women's movement and the exigencies of the Vietnam War combined to produce a dramatic change in the composition of law school student bodies in only a few years. The speed with which women continue to be incorporated into the legal profession will be affected by many factors. (MLW)

Modeling hygroelastic properties of genetically modified aspen

Treesearch

Laszlo Horvath; Perry Peralta; Ilona Peszlen; Levente Csoka; Balazs Horvath; Joseph Jakes

2012-01-01

Numerical and three-dimensional finite element models were developed to improve understanding of major factors affecting hygroelastic wood properties. Effects of chemical composition, microfibril angle, crystallinity, structure of microfibrils, moisture content, and hydrophilicity of the cell wall were included in the model. Wood from wild-type and decreased-lignin...

Temperature affect on caste differentiation and protein composition in Coptotermes formosanus

USDA-ARS?s Scientific Manuscript database

Caste systems, and the division of labor they make possible, are common underlying features of all social insects. In termites, multiple extrinsic factors have been shown to impact caste differentiation; for example, temperature has been shown to increase soldier production. The objective of this in...

PRESENTED 11/01/05 LAND-COVER CHARACTERIZATION AND CHANGE DETECTION USING MULTI-TEMPORAL MODIS NDVI DATA

EPA Science Inventory

Land-Cover (LC) composition and conversions are important factors that affect ecosystem condition and function. The purpose of this research and development effort is to investigate the feasibility of using MODIS derived Normalized Difference Vegetation Index (NDVI) data to deli...

Natural and anthropogenic factors affecting the shallow groundwater quality in a typical irrigation area with reclaimed water, North China Plain.

PubMed

Gu, Xiaomin; Xiao, Yong; Yin, Shiyang; Pan, Xingyao; Niu, Yong; Shao, Jingli; Cui, Yali; Zhang, Qiulan; Hao, Qichen

2017-09-22

In this study, the hydrochemical characteristics of shallow groundwater were analyzed to get insight into the factors affecting groundwater quality in a typical agricultural dominated area of the North China Plain. Forty-four shallow groundwater samples were collected for chemical analysis. The water type changes from Ca·Na-HCO 3 type in grass land to Ca·Na-Cl (+NO 3 ) type and Na (Ca)-Cl (+NO 3 +SO 4 ) type in construction and facility agricultural land, indicating the influence of human activities. The factor analysis and geostatistical analysis revealed that the two major factors contributing to the groundwater hydrochemical compositions were the water-rock interaction and contamination from sewage discharge and agricultural fertilizers. The major ions (F, HCO 3 ) and trace element (As) in the shallow groundwater represented the natural origin, while the nitrate and sulfate concentrations were related to the application of fertilizer and sewage discharge in the facility agricultural area, which was mainly affected by the human activities. The values of pH, total dissolved solids, electric conductivity, and conventional component (K, Ca, Na, Mg, Cl) in shallow groundwater increased from grass land and cultivated land, to construction land and to facility agriculture which were originated from the combination sources of natural processes (e.g., water-rock interaction) and human activities (e.g., domestic effluents). The study indicated that both natural processes and human activities had influences on the groundwater hydrochemical compositions in shallow groundwater, while anthropogenic processes had more contribution, especially in the reclaimed water irrigation area.

Factors and Trends Affecting the Identification of a Reliable Biomarker for Diesel Exhaust Exposure

PubMed Central

2014-01-01

The monitoring of human exposures to diesel exhaust continues to be a vexing problem for specialists seeking information on the potential health effects of this ubiquitous combustion product. Exposure biomarkers have yielded a potential solution to this problem by providing a direct measure of an individual's contact with key components in the exhaust stream. Spurred by the advent of new, highly sensitive, analytical methods capable of detecting substances at very low levels, there have been numerous attempts at identifying a stable and specific biomarker. Despite these new techniques, there is currently no foolproof method for unambiguously separating diesel exhaust exposures from those arising from other combustion sources. Diesel exhaust is a highly complex mixture of solid, liquid, and gaseous components whose exact composition can be affected by many variables, including engine technology, fuel composition, operating conditions, and photochemical aging. These factors together with those related to exposure methodology, epidemiological necessity, and regulatory reform can have a decided impact on the success or failure of future research aimed at identifying a suitable biomarker of exposure. The objective of this review is to examine existing information on exposure biomarkers for diesel exhaust and to identify those factors and trends that have had an impact on the successful identification of metrics for both occupational and community settings. The information will provide interested parties with a template for more thoroughly understanding those factors affecting diesel exhaust emissions and for identifying those substances and research approaches holding the greatest promise for future success. PMID:25170242

Differential associations of affective temperaments and diagnosis of major affective disorders with suicidal behavior.

PubMed

Baldessarini, Ross J; Innamorati, Marco; Erbuto, Denise; Serafini, Gianluca; Fiorillo, Andrea; Amore, Mario; Girardi, Paolo; Pompili, Maurizio

2017-03-01

Affective temperaments are associated with suicidal risk, but their predictive value relative to diagnosis of major affective disorder is uncertain. We compared diagnoses, affective-temperament ratings (TEMPS-A), and other potential risk factors in 956 psychiatric inpatients, using bivariate analyses and multivariable logistic regression modeling for associations with suicidal status. Lifetime suicide-attempt rates were high (43.9% overall), ranking by diagnosis: bipolar-II (58.4%), major depressive (50.0%), bipolar-I (44.6%), other (38.0%), and psychotic (33.9%) disorders. TEMPS-A scores for depressive (dep), cyclothymic (cyc), irritable (irr), and anxious (anx) temperaments and their sum were strongly associated with suicidal risk; hyperthymic (hyp) temperament scores were inversely associated; and a composite measure (dep+cyc+irr+anx - hyp), even more strongly associated. The composite score was highly, independently associated with suicidal behavior (p<0.0001), as was female sex (p=0.0002), but older age and diagnosis of major affective disorder, much less (both p=0.02). Measures of affective temperament-types were independently and more strongly associated with lifetime suicide attempt than was diagnosis of a major affective disorder. However, in this hospitalized cohort, suicide rates were high across diagnoses, possibly limiting the predictive value of diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

The Storage and Composition of Inflected Forms in Adult-Learned Second Language: A Study of the Influence of Length of Residence, Age of Arrival, Sex, and Other Factors

ERIC Educational Resources Information Center

Babcock, Laura; Stowe, John C.; Maloof, Christopher J.; Brovetto, Claudia; Ullman, Michael T.

2012-01-01

It remains unclear whether adult-learned second language (L2) depends on similar or different neurocognitive mechanisms as those involved in first language (L1). We examined whether English past tense forms are computed similarly or differently by L1 and L2 English speakers, and what factors might affect this: regularity (regular vs. irregular…

A narrative review of the associations between six bioactive components in breast milk and infant adiposity.

PubMed

Fields, David A; Schneider, Camille R; Pavela, Gregory

2016-06-01

This narrative review examines six important non-nutritive substances in breast milk, many of which were thought to have little to no biological significance. The overall objective is to provide background on key bioactive factors in breast milk believed to have an effect on infant outcomes (growth and body composition). The evidence for the effects of the following six bioactive compounds in breast milk on infant growth outcomes are reviewed: insulin, leptin, adiponectin, ghrelin, interleukin-6, and tumor necrosis factor-α. The existing literature on the effects of breast milk insulin, ghrelin, interleukin-6, and tumor necrosis factor-α and their associations with infant growth and adiposity is sparse. Of the bioactive compounds reviewed, leptin and adiponectin are the most researched. Data reveal that breast milk adiponectin has negative associations with growth in infancy. There is a need for innovative, well-designed studies to improve causal inference and advance our understanding in the effects of breast milk and its components on offspring growth and body composition. The recommendations provided, along with careful consideration of both known and unknown factors that affect breast milk composition, will help improve, standardize, and ultimately advance this emergent field. © 2016 The Obesity Society.

Factors affecting the bacterial community composition and heterotrophic production of Columbia River estuarine turbidity maxima.

PubMed

Herfort, Lydie; Crump, Byron C; Fortunato, Caroline S; McCue, Lee Ann; Campbell, Victoria; Simon, Holly M; Baptista, António M; Zuber, Peter

2017-12-01

Estuarine turbidity maxima (ETM) function as hotspots of microbial activity and diversity in estuaries, yet, little is known about the temporal and spatial variability in ETM bacterial community composition. To determine which environmental factors affect ETM bacterial populations in the Columbia River estuary, we analyzed ETM bacterial community composition (Sanger sequencing and amplicon pyrosequencing of 16S rRNA gene) and bulk heterotrophic production ( 3 H-leucine incorporation rates). We collected water 20 times to cover five ETM events and obtained 42 samples characterized by different salinities, turbidities, seasons, coastal regimes (upwelling vs. downwelling), locations, and particle size. Spring and summer populations were distinct. All May samples had similar bacterial community composition despite having different salinities (1-24 PSU), but summer non-ETM bacteria separated into marine, freshwater, and brackish assemblages. Summer ETM bacterial communities varied depending on coastal upwelling or downwelling conditions and on the sampling site location with respect to tidal intrusion during the previous neap tide. In contrast to ETM, whole (>0.2 μm) and free-living (0.2-3 μm) assemblages of non-ETM waters were similar to each other, indicating that particle-attached (>3 μm) non-ETM bacteria do not develop a distinct community. Brackish water type (ETM or non-ETM) is thus a major factor affecting particle-attached bacterial communities. Heterotrophic production was higher in particle-attached than free-living fractions in all brackish waters collected throughout the water column during the rise to decline of turbidity through an ETM event (i.e., ETM-impacted waters). However, free-living communities showed higher productivity prior to or after an ETM event (i.e., non-ETM-impacted waters). This study has thus found that Columbia River ETM bacterial communities vary based on seasons, salinity, sampling location, and particle size, with the existence of three particle types characterized by different bacterial communities in ETM, ETM-impacted, and non-ETM-impacted brackish waters. Taxonomic analysis suggests that ETM key biological function is to remineralize organic matter. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Possible Link Between Stress-related Factors and Altered Body Composition in Women with Polycystic Ovarian Syndrome

PubMed Central

Basu, Barnali Ray; Chowdhury, Olivia; Saha, Sudip Kumar

2018-01-01

Background: Stress is an invisible factor affecting modern day living and is strongly associated with many disease pathogenesis including polycystic ovarian syndrome (PCOS) in women. PCOS is the most frequent endocrinological disorder that affects women of reproductive age, leading to metabolic dysfunction and body composition alterations. Salivary amylase and cortisol are major stress mediators that have been implicated in PCOS. However, their role in altering body composition in PCOS is yet to be deciphered. Aim: The present study aimed at understanding the relation between stress-associated factors and alterations in body composition among PCOS patients. Design: This study enrolled a total of 100 patients (PCOS) and 60 age-matched controls. The female patients were of ages between 13 and 30 years. Materials and Methods: Standard assay kits were used to evaluate the α-amylase activity and cortisol level in saliva. The participants were chosen on the basis of the Rotterdam American Society for Reproductive Medicine/European Society of Human Reproduction criteria. Saliva was collected from each participant as per the protocol of Salimetrics, USA. Statistical Analysis: Statistical analysis was performed using SPSS version 20 for Windows. The quantitative variables are described as mean ± standard deviation. P < 0.05 was considered significant. Results: Increased salivary cortisol level and α-amylase activity were seen in the PCOS population as compared to age-matched controls suggesting patients a sustained stress scenario in their system. Moreover, overweight PCOS participants reflected higher amylase activity than the lean patients participants. Pulse rate, body mass index (BMI), visceral adiposity, and waist-hip ratio (WHR) was considerably higher in the PCOS patients participants compared to controls. A significant correlation could be drawn between the α-amylase activity and BMI or WHR, respectively, among PCOS patients. These observations indicate a strong link between the stress marker and alterations in the body composition parameters of PCOS patients participants. Conclusion: Higher prevalence of stress in PCOS patients participants has a critical role in their altered body composition. PMID:29681710

Seasonal dynamics of microbial community composition and function in oak canopy and open grassland soils

USGS Publications Warehouse

Waldrop, M.P.; Firestone, M.K.

2006-01-01

Soil microbial communities are closely associated with aboveground plant communities, with multiple potential drivers of this relationship. Plants can affect available soil carbon, temperature, and water content, which each have the potential to affect microbial community composition and function. These same variables change seasonally, and thus plant control on microbial community composition may be modulated or overshadowed by annual climatic patterns. We examined microbial community composition, C cycling processes, and environmental data in California annual grassland soils from beneath oak canopies and in open grassland areas to distinguish factors controlling microbial community composition and function seasonally and in association with the two plant overstory communities. Every 3 months for up to 2 years, we monitored microbial community composition using phospholipid fatty acid (PLFA) analysis, microbial biomass, respiration rates, microbial enzyme activities, and the activity of microbial groups using isotope labeling of PLFA biomarkers (13C-PLFA) . Distinct microbial communities were associated with oak canopy soils and open grassland soils and microbial communities displayed seasonal patterns from year to year. The effects of plant species and seasonal climate on microbial community composition were similar in magnitude. In this Mediterranean ecosystem, plant control of microbial community composition was primarily due to effects on soil water content, whereas the changes in microbial community composition seasonally appeared to be due, in large part, to soil temperature. Available soil carbon was not a significant control on microbial community composition. Microbial community composition (PLFA) and 13C-PLFA ordination values were strongly related to intra-annual variability in soil enzyme activities and soil respiration, but microbial biomass was not. In this Mediterranean climate, soil microclimate appeared to be the master variable controlling microbial community composition and function. ?? 2006 Springer Science+Business Media, Inc.

Factors affecting initial disability allowance rates for the Disability Insurance and Supplemental Security Income programs: the role of the demographic and diagnostic composition of applicants and local labor market conditions.

PubMed

Rupp, Kalman

2012-01-01

Various factors outside the control of decision makers may affect the rate at which disability applications are allowed or denied during the initial step of eligibility determination in the Social Security Disability Insurance (DI) and Supplemental Security Income (SSI) programs. In this article, using individual-level data on applications, I estimate the role of three important factors--the demographic characteristics of applicants, the diagnostic mix of applicants, and the local unemployment rate--in affecting the probability of an initial allowance and state allowance rates. I use a random sample of initial determinations from 1993 through 2008 and a fixed-effects multiple regression framework. The empirical results show that the demographic and diagnostic characteristics of applicants and the local unemployment rate substantially affect the initial allowance rate. An increase in the local unemployment rate tends to be associated with a decrease in the initial allowance rate. This negative relationship holds for adult DI and SSI applicants and for SSI childhood applicants.

Composition and structure of Pinus koraiensis mixed forest respond to spatial climatic changes.

PubMed

Zhang, Jingli; Zhou, Yong; Zhou, Guangsheng; Xiao, Chunwang

2014-01-01

Although some studies have indicated that climate changes can affect Pinus koraiensis mixed forest, the responses of composition and structure of Pinus koraiensis mixed forests to climatic changes are unknown and the key climatic factors controlling the composition and structure of Pinus koraiensis mixed forest are uncertain. Field survey was conducted in the natural Pinus koraiensis mixed forests along a latitudinal gradient and an elevational gradient in Northeast China. In order to build the mathematical models for simulating the relationships of compositional and structural attributes of the Pinus koraiensis mixed forest with climatic and non-climatic factors, stepwise linear regression analyses were performed, incorporating 14 dependent variables and the linear and quadratic components of 9 factors. All the selected new models were computed under the +2°C and +10% precipitation and +4°C and +10% precipitation scenarios. The Max Temperature of Warmest Month, Mean Temperature of Warmest Quarter and Precipitation of Wettest Month were observed to be key climatic factors controlling the stand densities and total basal areas of Pinus koraiensis mixed forest. Increased summer temperatures and precipitations strongly enhanced the stand densities and total basal areas of broadleaf trees but had little effect on Pinus koraiensis under the +2°C and +10% precipitation scenario and +4°C and +10% precipitation scenario. These results show that the Max Temperature of Warmest Month, Mean Temperature of Warmest Quarter and Precipitation of Wettest Month are key climatic factors which shape the composition and structure of Pinus koraiensis mixed forest. Although the Pinus koraiensis would persist, the current forests dominated by Pinus koraiensis in the region would all shift and become broadleaf-dominated forests due to the dramatic increase of broadleaf trees under the future global warming and increased precipitation.

Effects of the consumption of fish meals on the carotid IntimaMedia thickness in patients with hypertension: a prospective study.

PubMed

Colussi, GianLuca; Catena, Cristiana; Dialti, Valeria; Mos, Lucio; Sechi, Leonardo A

2014-01-01

The composition of dietary fat affects various modifiable cardiovascular risk factors and cardiovascular outcomes in the general population. We investigated the effects of the regular consumption of fish meals on the fatty acid composition of red blood cell (RBC) membranes and the relationship of this parameter with the carotid intima-media thickness (IMT), an early marker of atherosclerosis. In 56 hypertensive patients, we measured the carotid IMT using ultrasound imaging and the RBC membrane fatty acid composition using gas-chromatography and calculated the polyunsaturated to saturated fatty acid (PUFA/SFA) ratio. The patients received intensive nutritional counseling and three weekly meals of fish containing elevated amounts of PUFA, in order to increase the membrane PUFA content. The RBC membrane fatty acid composition and IMT were reassessed after one year. At baseline, the membrane PUFA/SFA ratio was inversely related to the carotid IMT, and the relationship was independent of all major cardiovascular risk factors. At follow-up, the PUFA/SFA ratio increased in the RBC membranes of 25 (45%) of 56 patients. The regular consumption of fish meals resulted in a decreased carotid IMT only in the patients with an increased membrane PUFA/SFA ratio. Changes in the PUFA/SFA ratio induced by the dietary intervention were inversely related to the changes in the IMT, independent of variations in body mass, blood pressure and plasma lipids. In hypertensive patients, a low RBC membrane PUFA/SFA ratio is associated with more prominent vascular damage, and the regular consumption of fish reduces the carotid IMT in patients in whom dietary intervention affects the membrane fatty acid composition.

Developing a model for cystic fibrosis sociomicrobiology based on antibiotic and environmental stress.

PubMed

Lopes, Susana Patrícia; Azevedo, Nuno Filipe; Pereira, Maria Olívia

2017-12-01

Cystic fibrosis (CF) infections are invariably biofilm-mediated and polymicrobial, being safe to assume that a myriad of factors affects the sociomicrobiology within the CF infection site and modulate the CF community dynamics, by shaping their social activities, overall functions, virulence, ultimately affecting disease outcome. This work aimed to assess changes in the dynamics (particularly on the microbial composition) of dual-/three-species biofilms involving CF-classical (Pseudomonas aeruginosa) and unusual species (Inquilinus limosus and Dolosigranulum pigrum), according to variable oxygen conditions and antibiotic exposure. Low fluctuations in biofilm compositions were observed across distinct oxygen environments, with dual-species biofilms exhibiting similar relative proportions and P. aeruginosa and/or D. pigrum populations dominating three-species consortia. Once exposed to antibiotics, biofilms displayed high resistance profiles, and microbial compositions, distributions, and microbial interactions significantly challenged. The antibiotic/oxygen environment supported such fluctuations, which enhanced for three-species communities. In conclusion, antibiotic therapy hugely disturbed CF communities' dynamics, inducing significant compositional changes on multispecies consortia. Clearly, multiple perturbations may disturb this dynamic, giving rise to various microbiological scenarios in vivo, and affecting disease phenotype. Therefore, an appreciation of the ecological/evolutionary nature within CF communities will be useful for the optimal use of current therapies and for newer breakthroughs on CF antibiotherapy. Copyright © 2017 Elsevier GmbH. All rights reserved.

Contribution of Fermentation Yeast to Final Amino Acid Profile in DDGS

USDA-ARS?s Scientific Manuscript database

One major factor affecting DDGS quality and market values is amino acid (AA) composition. DDGS proteins come from corn and yeast. Yet, the effect of fermentation yeast on DDGS protein quantity and quality (AA profile) has not been well documented. Based on literature review, there are at least 4 met...

Prescribing Control in Mixed Conifer Stands Affected by Annosus Root Disease

Treesearch

Gary Petersen

1989-01-01

Tree mortality caused by root diseases constitutes a major drain on Forest productivity of mixed-conifer stands. Factors such as changes in species composition, selective harvesting, unfavorable economic climate, and optimizing of short-term benefits have contributed to current stand conditions. Computer simulation models, such as the "RRMOD Computerized Root...

Vineyard soil bacterial diversity and composition revealed by 16S rRNA genes: Differentiation by vineyard management

USDA-ARS?s Scientific Manuscript database

Here, we demonstrate how vineyard management practices influence shifts in soil resources, which in turn affects shifts in soil-borne bacterial communities. The objective is to determine the hierarchical effects of management practices, soil attributes and location factors on the structure of soil-b...

Environmental factors affecting the spatial distribution and trophic interactions of arthropod communities at a bioenergy farm in the Southeastern Plains, USA

USDA-ARS?s Scientific Manuscript database

The abundance and composition of arthropod communities in agricultural landscapes vary across space and time, responding to environmental features, resources and behavioral cues. As “second-generation” bioenergy feedstocks continue to develop, knowledge is needed about the broader scale ecological i...

Characterization of soybean storage and allergen protein affected by environmental and genetic factors

USDA-ARS?s Scientific Manuscript database

Knowledge of the impact of genetic variability and diverse environments on the protein composition of crop seed is of value for the comparative safety assessments in the development of genetically engineered (GMO) crops. The objective of this study was to determine the role of genotype (G), environ...

Edaphic and microclimatic controls over permafrost response to fire in interior Alaska

Treesearch

D.R. Nossov; M.T. Jorgenson; K. Kielland; M. Kanevskiy

2013-01-01

Discontinuous permafrost in the North American boreal forest is strongly influenced by the effects of ecological succession on the accumulation of surface organic matter, making permafrost vulnerable to degradation resulting from fire disturbance. To assess factors affecting permafrost degradation after wildfire, we compared vegetation composition and soil properties...

Hispanic Students in Higher Education.

ERIC Educational Resources Information Center

Martinez-Perez, Luis A.

To reflect the changing composition of ethnic groups in the population and the recorded aspirations of hispanic high school seniors, institutions of higher education must prepare for a dramatic increase in the numbers of hispanics attending in the decade of the 1980's. Outlined in the paper are factors which affect hispanic (Cuban, Mexican, and…

Effect of alkaline treatment on mechanical properties of kenaf fiber reinforced polyester composites

NASA Astrophysics Data System (ADS)

Reddy, Bijjam Ramgopal; Dhoria, Sneha H.

2018-04-01

This paper focuses on the study of the effect of chemical treatment on mechanical properties such as tensile, flexural and impact properties of kenaf fiber reinforced polyester composites. Adhesion between the fiber and polymer is one of factors affecting the mechanical properties of composites. In order to increase the adhesion, the fibers are chemically treated with 5% of sodium hydroxide (NaOH) solution. The composite specimens are prepared in both untreated and treated forms of kenaf fibers with five levels of fiber volume fractions. The specimens are prepared according to ASTM standards. Mechanical tests such as tensile, flexural and impact are conducted to determine ultimate tensile strength, bending strength and impact strength of composites. The effect of change in volume fraction on the mechanical properties of the composites is studied for both untreated (raw) and chemically treated kenaf fibers. It has been found that the composites made of chemically treated fibers have good mechanical properties compared to untreated fibers.

Bulk chemical compositions of Antarctic meteorites in the NIPR collection

NASA Astrophysics Data System (ADS)

Kimura, M.; Imae, N.; Yamaguchi, A.; Haramura, H.; Kojima, H.

2018-03-01

Bulk chemical compositions of meteorites were traditionally analyzed by wet chemical analysis, and NIPR has data for 1162 meteorites as of September 2017. We discuss the classification of meteorites on the basis of these data. Chondrite data are distributed in an anomalously wide range of compositions on the Urey-Craig diagram. One of the reasons for such wide distribution is terrestrial weathering producing Fe2O3-bearing phases from Fe-Ni metal and sulfides. Another important factor affecting the bulk compositional data is brecciation. Our observations indicate that many brecciated chondrites contain anomalously abundant opaque minerals, or are depleted in them, resulting in unusual compositions. In case of enstatite and some carbonaceous chondrites, the bulk compositions are distributed in wider ranges than reported before. The bulk compositions of HED meteorites are consistent with their mineralogy and classification. Our study suggests that wet chemical data are still significant for the meteorite classification. However, petrographic observation is indispensable for evaluating the bulk chemistry and classification of meteorites.

Synthesis and Study of Optical Properties of Graphene/TiO2 Composites Using UV-VIS Spectroscopy

NASA Astrophysics Data System (ADS)

Rathod, P. B.; Waghuley, S. A.

2016-09-01

Graphene and TiO2 were synthesized using electrochemical exfoliation and co-precipitation methods, respectively. An ex situ approach was adopted for the graphene/TiO2 composites. The conformation of graphene in the TiO2 samples was examined through X-ray diffraction. Optical properties of the as-synthesised composites such as optical absorption, extinction coefficient, refractive index, real dielectric constant, imaginary dielectric constant, dissipation factor, and optical conductivity were measured using UV-Vis spectroscopy. The varying concentration of graphene in TiO2 affects the optical properties which appear different for 10 wt.% as compared to 5 wt.% graphene/ TiO2 composite. The composites exhibit an absorption peak at 300 nm with a decrease in band gap for 10 wt.% as compared to 5 wt.% graphene/TiO2 composite. The maximum optical conductivity for the graphene/TiO2 composite of 10 wt.% was found to be 1.86·10-2 Ω-1·m-1 at 300 nm.

Factors associated with long-term species composition in dry tropical forests of Central India

NASA Astrophysics Data System (ADS)

Agarwala, M.; DeFries, R. S.; Qureshi, Q.; Jhala, Y. V.

2016-10-01

The long-term future of species composition in forests depends on regeneration. Many factors can affect regeneration, including human use, environmental conditions, and species’ traits. This study examines the influence of these factors in a tropical deciduous forest of Central India, which is heavily used by local, forest-dependent residents for livestock grazing, fuel-wood extraction, construction and other livelihood needs. We measure size-class proportions (the ratio of abundance of a species at a site in a higher size class to total abundance in both lower and higher size classes) for 39 tree species across 20 transects at different intensities of human use. The size-class proportions for medium to large trees and for small to medium-sized trees were negatively associated with species that are used for local construction, while size class proportions for saplings to small trees were positively associated with those species that are fire resistant and negatively associated with livestock density. Results indicate that grazing and fire prevent non-fire resistant species from reaching reproductive age, which can alter the long term composition and future availability of species that are important for local use and ecosystem services. Management efforts to reduce fire and forest grazing could reverse these impacts on long-term forest composition.

Effect of five enological practices and of the general phenolic composition on fermentation-related aroma compounds in Mencia young red wines.

PubMed

Añón, Ana; López, Jorge F; Hernando, Diego; Orriols, Ignacio; Revilla, Eugenio; Losada, Manuel M

2014-04-01

The effects of five technological procedures and of the contents of total anthocyanins and condensed tannins on 19 fermentation-related aroma compounds of young red Mencia wines were studied. Multifactor ANOVA revealed that levels of those volatiles changed significantly over the length of storage in bottles and, to a lesser extent, due to other technological factors considered; total anthocyanins and condensed tannins also changed significantly as a result of the five practices assayed. Five aroma compounds possessed an odour activity value >1 in all wines, and another four in some wines. Linear correlation among volatile compounds and general phenolic composition revealed that total anthocyanins were highly related to 14 different aroma compounds. Multifactor ANOVA, considering the content of total anthocyanins as a sixth random factor, revealed that this parameter affected significantly the contents of ethyl lactate, ethyl isovalerate, 1-pentanol and ethyl octanoate. Thus, the aroma of young red Mencia wines may be affected by levels of total anthocyanins. Copyright © 2013 Elsevier Ltd. All rights reserved.

Prediction of transmittance spectra for transparent composite electrodes with ultra-thin metal layers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Zhao; Alford, T. L., E-mail: TA@asu.edu; Khorasani, Arash Elhami

2015-11-28

Recent interest in indium-free transparent composite-electrodes (TCEs) has motivated theoretical and experimental efforts to better understand and enhance their electrical and optical properties. Various tools have been developed to calculate the optical transmittance of multilayer thin-film structures based on the transfer-matrix method. However, the factors that affect the accuracy of these calculations have not been investigated very much. In this study, two sets of TCEs, TiO{sub 2}/Au/TiO{sub 2} and TiO{sub 2}/Ag/TiO{sub 2}, were fabricated to study the factors that affect the accuracy of transmittance predictions. We found that the predicted transmittance can deviate significantly from measured transmittance for TCEs thatmore » have ultra-thin plasmonic metal layers. The ultrathin metal layer in the TCE is typically discontinuous. When light interacts with the metallic islands in this discontinuous layer, localized surface plasmons are generated. This causes extra light absorption, which then leads to the actual transmittance being lower than the predicted transmittance.« less

Factors Affecting Optimal Surface Roughness of AISI 4140 Steel in Turning Operation Using Taguchi Experiment

NASA Astrophysics Data System (ADS)

Novareza, O.; Sulistiyarini, D. H.; Wiradmoko, R.

2018-02-01

This paper presents the result of using Taguchi method in turning process of medium carbon steel of AISI 4140. The primary concern is to find the optimal surface roughness after turning process. The taguchi method is used to get a combination of factors and factor levels in order to get the optimum surface roughness level. Four important factors with three levels were used in experiment based on Taguchi method. A number of 27 experiments were carried out during the research and analysed using analysis of variance (ANOVA) method. The result of surface finish was determined in Ra type surface roughness. The depth of cut was found to be the most important factors for reducing the surface roughness of AISI 4140 steel. On the contrary, the other important factors i.e. spindle speed and rake side angle of the tool were proven to be less factors that affecting the surface finish. It is interesting to see the effect of coolant composition that gained the second important factors to reduce the roughness. It may need further research to explain this result.

Astrobiological stoichiometry.

PubMed

Young, Patrick A; Desch, Steven J; Anbar, Ariel D; Barnes, Rory; Hinkel, Natalie R; Kopparapu, Ravikumar; Madhusudhan, Nikku; Monga, Nikhil; Pagano, Michael D; Riner, Miriam A; Scannapieco, Evan; Shim, Sang-Heon; Truitt, Amanda

2014-07-01

Chemical composition affects virtually all aspects of astrobiology, from stellar astrophysics to molecular biology. We present a synopsis of the research results presented at the "Stellar Stoichiometry" Workshop Without Walls hosted at Arizona State University April 11-12, 2013, under the auspices of the NASA Astrobiology Institute. The results focus on the measurement of chemical abundances and the effects of composition on processes from stellar to planetary scales. Of particular interest were the scientific connections between processes in these normally disparate fields. Measuring the abundances of elements in stars and giant and terrestrial planets poses substantial difficulties in technique and interpretation. One of the motivations for this conference was the fact that determinations of the abundance of a given element in a single star by different groups can differ by more than their quoted errors. The problems affecting the reliability of abundance estimations and their inherent limitations are discussed. When these problems are taken into consideration, self-consistent surveys of stellar abundances show that there is still substantial variation (factors of ∼ 2) in the ratios of common elements (e.g., C, O, Na, Al, Mg, Si, Ca) important in rock-forming minerals, atmospheres, and biology. We consider how abundance variations arise through injection of supernova nucleosynthesis products into star-forming material and through photoevaporation of protoplanetary disks. The effects of composition on stellar evolution are substantial, and coupled with planetary atmosphere models can result in predicted habitable zone extents that vary by many tens of percent. Variations in the bulk composition of planets can affect rates of radiogenic heating and substantially change the mineralogy of planetary interiors, affecting properties such as convection and energy transport.

Characteristics of diffusion zone in changing glass-metal composite processing conditions

NASA Astrophysics Data System (ADS)

Lyubimova, O. N.; Morkovin, A. V.; Andreev, V. V.

2018-03-01

The influence of manufacturing technology on the characteristics of the glass and steel contact zone in manufacturing new structural material - glass-metal composite is studied theoretically and experimentally. Different types of structures in the contact zone and its dimensions affect the strength characteristics of the composite. Knowledge about changing the width of the glass and steel contact zone after changing such parameters of the technological regime as temperature, holding time and use of solders will allow one to control the structure and characteristics of the glass-metal composite. Experimental measurements of the width of the diffusion zone in the glass-metal composite for different regimes and their statistical processing according to the full factor experiment are presented in this article. The results of analysis of some mechanical characteristics of the diffusion zone are presented: microhardness and modulus of elasticity for samples, prepared according to different processing regimes.

The arthropod, but not the vertebrate host or its environment, dictates bacterial community composition of fleas and ticks

PubMed Central

Hawlena, Hadas; Rynkiewicz, Evelyn; Toh, Evelyn; Alfred, Andrew; Durden, Lance A; Hastriter, Michael W; Nelson, David E; Rong, Ruichen; Munro, Daniel; Dong, Qunfeng; Fuqua, Clay; Clay, Keith

2013-01-01

Bacterial community composition in blood-sucking arthropods can shift dramatically across time and space. We used 16S rRNA gene amplification and pyrosequencing to investigate the relative impact of vertebrate host-related, arthropod-related and environmental factors on bacterial community composition in fleas and ticks collected from rodents in southern Indiana (USA). Bacterial community composition was largely affected by arthropod identity, but not by the rodent host or environmental conditions. Specifically, the arthropod group (fleas vs ticks) determined the community composition of bacteria, where bacterial communities of ticks were less diverse and more dependent on arthropod traits—especially tick species and life stage—than bacterial communities of fleas. Our data suggest that both arthropod life histories and the presence of arthropod-specific endosymbionts may mask the effects of the vertebrate host and its environment. PMID:22739493

Prevalence, pathophysiological mechanisms and factors affecting urolithiasis.

PubMed

Khan, Aslam

2018-05-01

The formation of urinary stone, urolithiasis, is one the oldest known disease affecting human throughout different civilizations and times. The exact pathophysiological mechanism of urolithiasis is not yet clear, as these calculi are of various types and too complex for simple understanding. A single theory cannot explain its formation; therefore, different theories are presented in various times for its explanation like free particle, fixed particle, Randall's plaque theory. In addition, various factors and components are identified that play an important role in the formation of these urinary calculi. In this review, composition of kidney stones, its prevalence/incidence, explanation of pathophysiological mechanisms and role of various factors; urinary pH, uric acid, parathyroid hormone, citrate, oxalate, calcium and macromolecules; osteopontin, matrix Gla protein, kidney injury molecules, urinary prothrombin fragment-1, Tamm-Horsfall protein, inter-α-inhibitors, have been discussed in detail.

Method for computing energy release rate using the elastic work factor approach

NASA Astrophysics Data System (ADS)

Rhee, K. Y.; Ernst, H. A.

1992-01-01

The elastic work factor eta(el) concept was applied to composite structures for the calculation of total energy release rate by using a single specimen. Cracked lap shear specimens with four different unidirectional fiber orientation were used to examine the dependence of eta(el) on the material properties. Also, three different thickness ratios (lap/strap) were used to determine how geometric conditions affect eta(el). The eta(el) values were calculated in two different ways: compliance method and crack closure method. The results show that the two methods produce comparable eta(el) values and, while eta(el) is affected significantly by geometric conditions, it is reasonably independent of material properties for the given geometry. The results also showed that the elastic work factor can be used to calculate total energy release rate using a single specimen.

Influence of polymerization time and depth of cure of resin composites determined by Vickers hardness.

PubMed

Lombardini, Marco; Chiesa, Marco; Scribante, Andrea; Colombo, Marco; Poggio, Claudio

2012-11-01

Adequate polymerization of resin composites could be considered as a crucial factor in obtaining good clinical performance, particularly in stress-bearing areas. An insufficient curing degree affects the resin composite's chemical properties The current in vitro study evaluated the influence of polymerization time and depth of cure of six commercial resin composites by Vickers microhardness (VK). SIX RESIN COMPOSITES WERE SELECTED: Three microhybrid (Esthet.X HD, Amaris, Filtek Silorane), two nanohybrid (Grandio, Ceram.X mono), and one nanofilled (Filtek Supreme XT). The VK of the surface was determined by a microhardness tester using a Vickers diamond indenter and a 200 g load applied for 15 s. The bottom to top mean VK ratio was calculated using the formula: Hardness ratio = VK of bottom surface/VK of top surface. Vickers hardness values of test materials during exposure time of 20 and 40 s and depths of cure of 2 and 3 mm were determined and compared. Data were analyzed using analysis of variance (ANOVA) test. For all the tested materials and with all the exposure time periods, hardness ratio was higher than the minimum value indicated in literature (0.8). Exposure time and depth of cure did not affect hardness ratio values for Filtek Silorane, Grandio, and Filtek Supreme XT. Among the materials tested, the nanofilled and the nanohybrid resin composites were rather insensible to thickness variations. Miicrohybrid composites, instead, had features different from one another.

Effect of the feeding system on the fatty acid composition, expression of the Δ9-desaturase, Peroxisome Proliferator-Activated Receptor Alpha, Gamma, and Sterol Regulatory Element Binding Protein 1 genes in the semitendinous muscle of light lambs of the Rasa Aragonesa breed

PubMed Central

2010-01-01

Background Conjugated linoleic acids (CLAs) are receiving increasing attention because of their beneficial effects on human health, with milk and meat products derived from ruminants as important sources of CLA in the human diet. SCD gene is responsible for some of the variation in CLA concentration in adipose tissues, and PPARγ, PPARα and SREBP1 genes are regulator of SCD gene. The aim of this work was to evaluate the effect of the feeding system on fatty acid composition, CLA content and relative gene expression of Δ9-desaturase (SCD), Peroxisome Proliferator-Activated Receptor Gamma (PPARγ), Peroxisome Proliferator-Activated Receptor Alpha, (PPARα) and Sterol Regulatory Element Binding Protein (SREBP1) in Rasa Aragonesa light lambs in semitendinous muscle. Forty-four single-born male lambs were used to evaluate the effect of the feeding system, varying on an intensity gradient according to the use of concentrates: 1. grazing alfalfa, 2. grazing alfalfa with a supplement for lambs, 3. indoor lambs with grazing ewes and 4. drylot. Results Both grazing systems resulted in a higher concentration of vaccenic acid (VA), CLA, CLA/VA acid ratio, and a lower oleic content, oleic acid (C18:1)/stearic acid (C18:0) ratio, PUFA n-6/n-3 ratio and SCD expression compared to other diets. In addition feeding system affected the fatty acid composition and SCD expression, possibly due to CLA concentration or the PUFA n-6/n-3 ratio. Both expression of the SCD gene and the feeding system were important factors affecting CLA concentration in the animal's semitendinous muscle. PPARγ, PPARα and SREBP1 expression seemed to be unaffected by the feeding system. Although no significant results were found, PPARγ, PPARα and SREBP1 showed similar expression pattern as SCD. Moreover, the correlation results between SCD expression and PPARγ (p < 0.01), as well as SREBP1 (p < 0.01) expression, may suggest that these genes were affecting SCD expression in a different way. Conclusions The data indicated that the feeding system is the main factor affecting the fatty acid composition and SCD gene expression, which is also affected by CLA and possibly by n-6/n-3 PUFAs. PMID:20649987

Effects of abiotic stress and crop management on cereal grain composition: implications for food quality and safety.

PubMed

Halford, Nigel G; Curtis, Tanya Y; Chen, Zhiwei; Huang, Jianhua

2015-03-01

The effects of abiotic stresses and crop management on cereal grain composition are reviewed, focusing on phytochemicals, vitamins, fibre, protein, free amino acids, sugars, and oils. These effects are discussed in the context of nutritional and processing quality and the potential for formation of processing contaminants, such as acrylamide, furan, hydroxymethylfurfuryl, and trans fatty acids. The implications of climate change for cereal grain quality and food safety are considered. It is concluded that the identification of specific environmental stresses that affect grain composition in ways that have implications for food quality and safety and how these stresses interact with genetic factors and will be affected by climate change needs more investigation. Plant researchers and breeders are encouraged to address the issue of processing contaminants or risk appearing out of touch with major end-users in the food industry, and not to overlook the effects of environmental stresses and crop management on crop composition, quality, and safety as they strive to increase yield. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Community shifts under climate change: mechanisms at multiple scales.

PubMed

Gornish, Elise S; Tylianakis, Jason M

2013-07-01

Processes that drive ecological dynamics differ across spatial scales. Therefore, the pathways through which plant communities and plant-insect relationships respond to changing environmental conditions are also expected to be scale-dependent. Furthermore, the processes that affect individual species or interactions at single sites may differ from those affecting communities across multiple sites. We reviewed and synthesized peer-reviewed literature to identify patterns in biotic or abiotic pathways underpinning changes in the composition and diversity of plant communities under three components of climate change (increasing temperature, CO2, and changes in precipitation) and how these differ across spatial scales. We also explored how these changes to plants affect plant-insect interactions. The relative frequency of biotic vs. abiotic pathways of climate effects at larger spatial scales often differ from those at smaller scales. Local-scale studies show variable responses to climate drivers, often driven by biotic factors. However, larger scale studies identify changes to species composition and/or reduced diversity as a result of abiotic factors. Differing pathways of climate effects can result from different responses of multiple species, habitat effects, and differing effects of invasions at local vs. regional to global scales. Plant community changes can affect higher trophic levels as a result of spatial or phenological mismatch, foliar quality changes, and plant abundance changes, though studies on plant-insect interactions at larger scales are rare. Climate-induced changes to plant communities will have considerable effects on community-scale trophic exchanges, which may differ from the responses of individual species or pairwise interactions.

Factors That Affect Large Subunit Ribosomal DNA Amplicon Sequencing Studies of Fungal Communities: Classification Method, Primer Choice, and Error

PubMed Central

Porter, Teresita M.; Golding, G. Brian

2012-01-01

Nuclear large subunit ribosomal DNA is widely used in fungal phylogenetics and to an increasing extent also amplicon-based environmental sequencing. The relatively short reads produced by next-generation sequencing, however, makes primer choice and sequence error important variables for obtaining accurate taxonomic classifications. In this simulation study we tested the performance of three classification methods: 1) a similarity-based method (BLAST + Metagenomic Analyzer, MEGAN); 2) a composition-based method (Ribosomal Database Project naïve Bayesian classifier, NBC); and, 3) a phylogeny-based method (Statistical Assignment Package, SAP). We also tested the effects of sequence length, primer choice, and sequence error on classification accuracy and perceived community composition. Using a leave-one-out cross validation approach, results for classifications to the genus rank were as follows: BLAST + MEGAN had the lowest error rate and was particularly robust to sequence error; SAP accuracy was highest when long LSU query sequences were classified; and, NBC runs significantly faster than the other tested methods. All methods performed poorly with the shortest 50–100 bp sequences. Increasing simulated sequence error reduced classification accuracy. Community shifts were detected due to sequence error and primer selection even though there was no change in the underlying community composition. Short read datasets from individual primers, as well as pooled datasets, appear to only approximate the true community composition. We hope this work informs investigators of some of the factors that affect the quality and interpretation of their environmental gene surveys. PMID:22558215

The role of hydrodynamics in shaping the composition and architecture of epilithic biofilms in fluvial ecosystems.

PubMed

Risse-Buhl, Ute; Anlanger, Christine; Kalla, Katalin; Neu, Thomas R; Noss, Christian; Lorke, Andreas; Weitere, Markus

2017-12-15

Previous laboratory and on-site experiments have highlighted the importance of hydrodynamics in shaping biofilm composition and architecture. In how far responses to hydrodynamics can be found in natural flows under the complex interplay of environmental factors is still unknown. In this study we investigated the effect of near streambed turbulence in terms of turbulent kinetic energy (TKE) on the composition and architecture of biofilms matured in two mountainous streams differing in dissolved nutrient concentrations. Over both streams, TKE significantly explained 7% and 8% of the variability in biofilm composition and architecture, respectively. However, effects were more pronounced in the nutrient richer stream, where TKE significantly explained 12% and 3% of the variability in biofilm composition and architecture, respectively. While at lower nutrient concentrations seasonally varying factors such as stoichiometry of dissolved nutrients (N/P ratio) and light were more important and explained 41% and 6% of the variability in biofilm composition and architecture, respectively. Specific biofilm features such as elongated ripples and streamers, which were observed in response to the uniform and unidirectional flow in experimental settings, were not observed. Microbial biovolume and surface area covered by the biofilm canopy increased with TKE, while biofilm thickness and porosity where not affected or decreased. These findings indicate that under natural flows where near bed flow velocities and turbulence intensities fluctuate with time and space, biofilms became more compact. They spread uniformly on the mineral surface as a film of densely packed coccoid cells appearing like cobblestone pavement. The compact growth of biofilms seemed to be advantageous for resisting hydrodynamic shear forces in order to avoid displacement. Thus, near streambed turbulence can be considered as important factor shaping the composition and architecture of biofilms grown under natural flows. Copyright © 2017 Elsevier Ltd. All rights reserved.

Electronic band structure and optical gain of GaN{sub x}Bi{sub y}As{sub 1−x−y}/GaAs pyramidal quantum dots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Zhi-Gang; State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083; Bose, Sumanta

The electronic band structure and optical gain of GaN{sub x}Bi{sub y}As{sub 1−x−y}/GaAs pyramidal quantum dots (QDs) are investigated using the 16-band k ⋅ p model with constant strain. The optical gain is calculated taking both homogeneous and inhomogeneous broadenings into consideration. The effective band gap falls as we increase the composition of nitrogen (N) and bismuth (Bi) and with an appropriate choice of composition we can tune the emission wavelength to span within 1.3 μm–1.55 μm, for device application in fiber technology. The extent of this red shift is more profound in QDs compared with bulk material due to quantum confinement. Othermore » factors affecting the emission characteristics include virtual crystal, strain profile, band anticrossing (BAC), and valence band anticrossing (VBAC). The strain profile has a profound impact on the electronic structure, specially the valence band of QDs, which can be determined using the composition distribution of wave functions. All these factors eventually affect the optical gain spectrum. With an increase in QD size, we observe a red shift in the emission energy and emergence of secondary peaks owing to transitions or greater energy compared with the fundamental transition.« less

40 CFR 63.5795 - How do I know if my reinforced plastic composites production facility is a new affected source or...

Code of Federal Regulations, 2010 CFR

2010-07-01

... composites production facility is a new affected source or an existing affected source? 63.5795 Section 63... for Hazardous Air Pollutants: Reinforced Plastic Composites Production What This Subpart Covers § 63.5795 How do I know if my reinforced plastic composites production facility is a new affected source or...

¹H NMR and multivariate data analysis of the relationship between the age and quality of duck meat.

PubMed

Liu, Chunli; Pan, Daodong; Ye, Yangfang; Cao, Jinxuan

2013-11-15

To contribute to a better understanding of the factors affecting meat quality, we investigated the influence of age on the chemical composition of duck meat. Aging probably affects the quality of meat through changes in metabolism. Therefore, we studied the metabolic composition of duck meat using (1)H nuclear magnetic resonance (NMR) spectroscopy. Comprehensive multivariate data analysis showed significant differences between extracts from ducks that had been aged for four different time periods. Although lactate and anserine increased with age, fumarate, betaine, taurine, inosine and alkyl-substituted free amino acids decreased. These results contribute to a better understanding of changes in duck meat metabolism as meat ages, which could be used to help assess the quality of duck meat as a food. Copyright © 2013 Elsevier Ltd. All rights reserved.

Measuring breath acetone for monitoring fat loss: Review

PubMed Central

2015-01-01

Objective Endogenous acetone production is a by‐product of the fat metabolism process. Because of its small size, acetone appears in exhaled breath. Historically, endogenous acetone has been measured in exhaled breath to monitor ketosis in healthy and diabetic subjects. Recently, breath acetone concentration (BrAce) has been shown to correlate with the rate of fat loss in healthy individuals. In this review, the measurement of breath acetone in healthy subjects is evaluated for its utility in predicting fat loss and its sensitivity to changes in physiologic parameters. Results BrAce can range from 1 ppm in healthy non‐dieting subjects to 1,250 ppm in diabetic ketoacidosis. A strong correlation exists between increased BrAce and the rate of fat loss. Multiple metabolic and respiratory factors affect the measurement of BrAce. BrAce is most affected by changes in the following factors (in descending order): dietary macronutrient composition, caloric restriction, exercise, pulmonary factors, and other assorted factors that increase fat metabolism or inhibit acetone metabolism. Pulmonary factors affecting acetone exchange in the lung should be controlled to optimize the breath sample for measurement. Conclusions When biologic factors are controlled, BrAce measurement provides a non‐invasive tool for monitoring the rate of fat loss in healthy subjects. PMID:26524104

Measuring breath acetone for monitoring fat loss: Review.

PubMed

Anderson, Joseph C

2015-12-01

Endogenous acetone production is a by-product of the fat metabolism process. Because of its small size, acetone appears in exhaled breath. Historically, endogenous acetone has been measured in exhaled breath to monitor ketosis in healthy and diabetic subjects. Recently, breath acetone concentration (BrAce) has been shown to correlate with the rate of fat loss in healthy individuals. In this review, the measurement of breath acetone in healthy subjects is evaluated for its utility in predicting fat loss and its sensitivity to changes in physiologic parameters. BrAce can range from 1 ppm in healthy non-dieting subjects to 1,250 ppm in diabetic ketoacidosis. A strong correlation exists between increased BrAce and the rate of fat loss. Multiple metabolic and respiratory factors affect the measurement of BrAce. BrAce is most affected by changes in the following factors (in descending order): dietary macronutrient composition, caloric restriction, exercise, pulmonary factors, and other assorted factors that increase fat metabolism or inhibit acetone metabolism. Pulmonary factors affecting acetone exchange in the lung should be controlled to optimize the breath sample for measurement. When biologic factors are controlled, BrAce measurement provides a non-invasive tool for monitoring the rate of fat loss in healthy subjects. © 2015 The Authors Obesity published by Wiley Periodicals, Inc. on behalf of The Obesity Society (TOS).

Factors Affecting 25-Hydroxyvitamin D Concentration in Response to Vitamin D Supplementation

PubMed Central

Mazahery, Hajar; von Hurst, Pamela R.

2015-01-01

Sun exposure is the main source of vitamin D. Due to many lifestyle risk factors vitamin D deficiency/insufficiency is becoming a worldwide health problem. Low 25(OH)D concentration is associated with adverse musculoskeletal and non-musculoskeletal health outcomes. Vitamin D supplementation is currently the best approach to treat deficiency and to maintain adequacy. In response to a given dose of vitamin D, the effect on 25(OH)D concentration differs between individuals, and it is imperative that factors affecting this response be identified. For this review, a comprehensive literature search was conducted to identify those factors and to explore their significance in relation to circulating 25(OH)D response to vitamin D supplementation. The effect of several demographic/biological factors such as baseline 25(OH)D, aging, body mass index(BMI)/body fat percentage, ethnicity, calcium intake, genetics, oestrogen use, dietary fat content and composition, and some diseases and medications has been addressed. Furthermore, strategies employed by researchers or health care providers (type, dose and duration of vitamin D supplementation) and environment (season) are other contributing factors. With the exception of baseline 25(OH)D, BMI/body fat percentage, dose and type of vitamin D, the relative importance of other factors and the mechanisms by which these factors may affect the response remains to be determined. PMID:26121531

Design and Validation of a Web-Based System for Assigning Members to Teams Using Instructor-Specified Criteria

ERIC Educational Resources Information Center

Layton, Richard A.; Loughry, Misty L.; Ohland, Matthew W.; Ricco, George D.

2010-01-01

A significant body of research identifies a large number of team composition characteristics that affect the success of individuals and teams in cooperative learning and project-based team environments. Controlling these factors when assigning students to teams should result in improved learning experiences. However, it is very difficult for…

Factors Affecting Variance in Classroom Assessment Scoring System Scores: Season, Context, and Classroom Composition

ERIC Educational Resources Information Center

Buell, Martha; Han, Myae; Vukelich, Carol

2017-01-01

Early care and education programme quality is usually assessed at the classroom level. One such measure of classroom quality is the classroom assessment scoring system (CLASS). In an effort to ensure higher quality programming, the CLASS is being used to direct teacher professional development. However, there has been relatively little research on…

Perceptions of Factors Affecting the Relative Effectiveness of Temporary Blue Ribbon State Commissions.

ERIC Educational Resources Information Center

Johnson, Janet Rogers-Clarke

Elements in the composition and process of higher education blue ribbon commissions that influence their effectiveness were studied. Blue ribbon commissions, which have been used as one type of statewide planning strategy, are defined here as commissions with (1) a predetermined life span; (2) authority established by the legislature and/or the…

Altered genotypic and phenotypic frequencies of aphid populations under enriched CO2 and O3 atmospheres

Treesearch

Edward B. Mondor; Michelle N. Tremblay; Caroline S. Awmack; Richard L. Lindroth

2005-01-01

Environmental change is anticipated to negatively affect both plant and animal populations. As abiotic factors rapidly change habitat suitability, projections range from altered genetic diversity to wide-spread species loss. Here, we assess the degree to which changes in atmospheric composition associated with environmental change will influence not only the abundance...

Factors related to building loss due to wildfires in the conterminous United States

Treesearch

Patricia M. Alexandre; Susan I. Stewart; Nicholas S. Keuler; Murray K. Clayton; Miranda H. Mockrin; Avi Bar-Massada; Alexandra D. Syphard; Volker C. Radeloff

2016-01-01

Wildfire is globally an important ecological disturbance affecting biochemical cycles and vegetation composition, but also puts people and their homes at risk. Suppressing wildfires has detrimental ecological effects and can promote larger and more intense wildfires when fuels accumulate, which increases the threat to buildings in the wildland- urban interface (WUI)....

The Social Context of Education. Findings from "The Condition of Education, 1997," No. 10.

ERIC Educational Resources Information Center

Young, Beth Aronstamm; Smith, Thomas M.

Data from "The Condition of Education, 1997" are used to show how changes over time in the composition of students in terms of factors such as student English language proficiency, family income, parents' education, and family structure affect the social context of education. This report traces associations between these student-level social…

Market and Institutional Sources of Educational Growth. Discussion Paper No. 494-78.

ERIC Educational Resources Information Center

Mare, Robert D.

In this paper, research from several traditions is synthesized to discern causes of change in the level of formal educational attainment in the United States for cohorts during the first half of the twentieth century. Two sources of educational growth are considered: (1) changing population composition on family background factors that affect how…

Songbird abundance and parasatism differ between urban and rural shrublands

Treesearch

Dirk E. Burhans; Frank R. Thompson

2006-01-01

Many studies have examined differences in avian community composition between urban and rural habitats, but few, if any, have looked at nesting success of urban shrubland birds in a replicated fashion while controlling for habitat. We tested factors affecting nest survival, parasitism by the Brown-headed Cowbird (Molothrus ater), and species abundance in shrubland...

Effect of chemical treatment of Kevlar fibers on mechanical interfacial properties of composites.

PubMed

Park, Soo-Jin; Seo, Min-Kang; Ma, Tae-Jun; Lee, Douk-Rae

2002-08-01

In this work, the effects of chemical treatment on Kevlar 29 fibers have been studied in a composite system. The surface characteristics of Kevlar 29 fibers were characterized by pH, acid-base value, X-ray photoelectron spectroscopy (XPS), and FT-IR. The mechanical interfacial properties of the final composites were studied by interlaminar shear strength (ILSS), critical stress intensity factor (K(IC)), and specific fracture energy (G(IC)). Also, impact properties of the composites were investigated in the context of differentiating between initiation and propagation energies and ductile index (DI) along with maximum force and total energy. As a result, it was found that chemical treatment with phosphoric acid solution significantly affected the degree of adhesion at interfaces between fibers and resin matrix, resulting in improved mechanical interfacial strength in the composites. This was probably due to the presence of chemical polar groups on Kevlar surfaces, leading to an increment of interfacial binding force between fibers and matrix in a composite system.

Chemical composition and biological activity of essential oils of Origanum vulgare L. subsp. vulgare L. under different growth conditions.

PubMed

De Falco, Enrica; Mancini, Emilia; Roscigno, Graziana; Mignola, Enrico; Taglialatela-Scafati, Orazio; Senatore, Felice

2013-12-04

This research was aimed at investigating the essential oil production, chemical composition and biological activity of a crop of pink flowered oregano (Origanum vulgare L. subsp. vulgare L.) under different spatial distribution of the plants (single and binate rows). This plant factor was shown to affect its growth, soil covering, fresh biomass, essential oil amount and composition. In particular, the essential oil percentage was higher for the binate row treatment at the full bloom. The chemical composition of the oils obtained by hydrodistillation was fully characterized by GC and GC-MS. The oil from plants grown in single rows was rich in sabinene, while plants grown in double rows were richer in ocimenes. The essential oils showed antimicrobial action, mainly against Gram-positive pathogens and particularly Bacillus cereus and B. subtilis.

[Distribution and seasonal dynamics of meiofauna in intertidal zone of Qingdao sandy beaches, Shandong Province of East China].

PubMed

Li, Ha; Hua, Er; Zhang, Zhi-Nan

2012-12-01

An investigation was conducted on the abundance, group composition, and distribution of meiofauna at the Second Beach of Taiping Bay and the Shilaoren Beach in Qingdao in January, April, July, and October 2008, aimed to analyze the distribution and seasonal dynamics of meiofauna in the intertidal zone of Qingdao sandy beaches. The measurements of environmental factors, including sediment grain size, interstitial water salinity, interstitial water temperature, organic matter content (TOC), and chlorophyll a (Chl a) content, were made simultaneously. There existed obvious seasonal differences in the environment factors, which could be clustered into two groups, i. e. , spring-winter group (January and April) and summer-autumn group (July and October). At the Second Beach of Taiping Bay, the mean annual abundance of meiofauna was (1167.3 +/- 768.3) ind x 10 cm(-2), and the most dominant group was Nematoda, accounting for 91% of the total. The meiofaunal group composition and abundance at the Second Beach differed horizontally, with the abundance ranked as high tide zone < middle tide zone < low tide zone. The meiofaunal group composition and abundance also varied seasonally, with high values in spring/winter and low values in summer/autumn (spring > winter > autumn > summer). The vertical distribution of the meiofauna in the high and middle tide zones of the Second Beach varied seasonally too. The meiofauna migrated downward with increasing temperature, concentrated in surface layer in winter and migrated downward in summer. At the Shilaoren Beach, the mean annual abundance of meiofauna was (1130.2 +/- 1419.1) ind x 10 cm(-2), and Nematoda accounted for 85% of the total. There was a great similarity of the environmental factors in the middle tide zone of the Second Beach and Shilaoren Beach, which led to no differences in the meiofaunal group composition and abundance. However, the vertical distribution of the meiofauna differed between the two beaches. When the temperature decreased, the meiofauna at Shilaoren Beach migrated downward. The ANOVA and BIOENV analyses showed that the TOC and MD phi were most responsible for the distribution of meiofauna among the tidal zones, the interstitial water temperature, MD phi, and TOC were the main causes of the seasonal variation of meiofaunal group composition and abundance, whereas the sediment Chl a affected the vertical migration of meiofauna. Tourism-induced sediment variation was another factor affecting the meiofaunal abundance, group composition, and distribution.

Essential oil variation in wild populations of Artemisia saharae (Asteraceae) from Tunisia: chemical composition, antibacterial and antioxidant properties.

PubMed

Zouari, Sami; Ayadi, Imen; Fakhfakh, Nahed; Jdir, Hamida; Aloui, Latifa; Kossentini, Mohamed; Rebai, Ahmed; Zouari, Nacim

2014-12-01

Artemisia saharae Pomel is a new taxon of Artemisia herba-alba Asso (Asteraceae) which is endemic to Tunisia and Algeria. This shrub, commonly known as white wormwood or desert wormwood, is largely used in folk medicine and as a culinary herb. The bulks aromatic plants come from wild populations whose essential oils compositions as well as their biological properties are severely affected by several factors such as geographic conditions. Therefore, the aim of the present work is to provide more information about the influence of altitude variation on the essential oil composition, antimicrobial and antioxidant properties of Artemisia saharae growing wild in the same geographical area. Essential oils were extracted by hydrodistillation of leaves and flowers of the plant collected from seven different altitudes of the Baten Zamour region (southwest of Tunisia). The highest essential oil yields (2.70-2.80%) were obtained for populations of high altitudes. Seventy-five compounds, representing 92.78 to 96.95% of the total essential oils, were separated and identified. Essential oils were characterized by very high percentage of oxygenated monoterpenes (52.1-72.6%) which constituted the predominant class. From the analyzed populations, the major compounds (>7%) were α-thujone, β-thujone, chrysanthenone, camphor, chrysanthenyl acetate, and sabinyl acetate. Sabinyl acetate which was detected in some populations at relatively high percentages (7.7-10.8%) seems to be characteristic to Southern Tunisian A. saharae. The studied essential oil showed a chemical diversity depending on the population altitude as revealed by linear discriminant and cluster analyses. Three population groups associated with altitudinal levels were distinguished. It is worthy to note that the most discriminating compounds of chemical groups were the minor ones. Despite the high variation of essential oil compositions, the high altitude population did not affect severely the antibacterial activity against the most tested strains. Altitude seems to be an important factor influencing the yield and the chemical profile of Artemisia saharae essential oils. Knowledge of the chemical composition of essential oils in relation to environmental factors is a very important quality criterion for their marketing and contributes to their valorization as functional ingredient in food technology.

Genetic loci simultaneously controlling lignin monomers and biomass digestibility of rice straw.

PubMed

Hu, Zhen; Zhang, Guifen; Muhammad, Ali; Samad, Rana Abdul; Wang, Youmei; Walton, Jonathan D; He, Yuqing; Peng, Liangcai; Wang, Lingqiang

2018-02-26

Lignin content and composition are crucial factors affecting biomass digestibility. Exploring the genetic loci simultaneously affecting lignin-relevant traits and biomass digestibility is a precondition for lignin genetic manipulation towards energy crop breeding. In this study, a high-throughput platform was employed to assay the lignin content, lignin composition and biomass enzymatic digestibility of a rice recombinant inbred line population. Correlation analysis indicated that the absolute content of lignin monomers rather than lignin content had negative effects on biomass saccharification, whereas the relative content of p-hydroxyphenyl unit and the molar ratio of p-hydroxyphenyl unit to guaiacyl unit exhibited positive roles. Eight QTL clusters were identified and four of them affecting both lignin composition and biomass digestibility. The additive effects of clustered QTL revealed consistent relationships between lignin-relevant traits and biomass digestibility. Pyramiding rice lines containing the above four positive alleles for increasing biomass digestibility were selected and showed comparable lignin content, decreased syringyl or guaiacyl unit and increased molar percentage of p-hydroxyphenyl unit, the molar ratio of p-hydroxyphenyl unit to guaiacyl unit and sugar releases. More importantly, the lodging resistance and eating/cooking quality of pyramiding lines were not sacrificed, indicating the QTL information could be applied to select desirable energy rice lines.

Assemblage composition of fungal wood-decay species has a major influence on how climate and wood quality modify decomposition.

PubMed

Venugopal, Parvathy; Junninen, Kaisa; Edman, Mattias; Kouki, Jari

2017-03-01

The interactions among saprotrophic fungal species, as well as their interactions with environmental factors, may have a major influence on wood decay and carbon release in ecosystems. We studied the effect that decomposer diversity (species richness and assemblage composition) has on wood decomposition when the climatic variables and substrate quality vary simultaneously. We used two temperatures (16 and 21°C) and two humidity levels (70% and 90%) with two wood qualities (wood from managed and old-growth forests) of Pinus sylvestris. In a 9-month experiment, the effects of fungal diversity were tested using four wood-decaying fungi (Antrodia xantha, Dichomitus squalens, Fomitopsis pinicola and Gloeophyllum protractum) at assemblage levels of one, two and four species. Wood quality and assemblage composition affected the influence of climatic factors on decomposition rates. Fungal assemblage composition was found to be more important than fungal species richness, indicating that species-specific fungal traits are of paramount importance in driving decomposition. We conclude that models containing fungal wood-decay species (and wood-based carbon) need to take into account species-specific and assemblage composition-specific properties to improve predictive capacity in regard to decomposition-related carbon dynamics. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effect of puberty on body composition.

PubMed

Loomba-Albrecht, Lindsey A; Styne, Dennis M

2009-02-01

Here we examine the effect of puberty on components of human body composition, including adiposity (total body fat, percentage body fat and fat distribution), lean body mass and bone mineral content and density. New methods and longitudinal studies have expended our knowledge of these remarkable changes. Human differences in adiposity, fat free mass and bone mass reflect differences in endocrine status (particularly with respect to estrogens, androgens, growth hormone and IGF-1), genetic factors, ethnicity and the environment. During puberty, males gain greater amounts of fat free mass and skeletal mass, whereas females acquire significantly more fat mass. Both genders reach peak bone accretion during the pubertal years, though males develop a greater skeletal mass. Body proportions and fat distribution change during the pubertal years as well, with males assuming a more android body shape and females assuming a more gynecoid shape. Pubertal body composition may predict adult body composition and affects both pubertal timing and future health. Sexual dimorphism exists to a small degree at birth, but striking differences develop during the pubertal years. The development of this dimorphism in body composition is largely regulated by endocrine factors, with critical roles played by growth hormone and gonadal steroids. It is important for clinicians and researchers to know the normal changes in order to address pathologic findings in disease states.

Adhesive/Dentin Interface: The Weak Link in the Composite Restoration

PubMed Central

Spencer, Paulette; Ye, Qiang; Park, Jonggu; Topp, Elizabeth M.; Misra, Anil; Marangos, Orestes; Wang, Yong; Bohaty, Brenda S.; Singh, Viraj; Sene, Fabio; Eslick, John; Camarda, Kyle; Katz, J. Lawrence

2010-01-01

Results from clinical studies suggest that more than half of the 166 million dental restorations that were placed in the United States in 2005 were replacements for failed restorations. This emphasis on replacement therapy is expected to grow as dentists use composite as opposed to dental amalgam to restore moderate to large posterior lesions. Composite restorations have higher failure rates, more recurrent caries, and increased frequency of replacement as compared to amalgam. Penetration of bacterial enzymes, oral fluids, and bacteria into the crevices between the tooth and composite undermines the restoration and leads to recurrent decay and premature failure. Under in vivo conditions the bond formed at the adhesive/dentin interface can be the first defense against these noxious, damaging substances. The intent of this article is to review structural aspects of the clinical substrate that impact bond formation at the adhesive/dentin interface; to examine physico-chemical factors that affect the integrity and durability of the adhesive/dentin interfacial bond; and to explore how these factors act synergistically with mechanical forces to undermine the composite restoration. The article will examine the various avenues that have been pursued to address these problems and it will explore how alterations in material chemistry could address the detrimental impact of physico-chemical stresses on the bond formed at the adhesive/dentin interface. PMID:20195761

Shrinkage strain-rates of dental resin-monomer and composite systems.

PubMed

Atai, Mohammad; Watts, David C; Atai, Zahra

2005-08-01

The purpose of this study was to investigate the shrinkage strain rate of different monomers, which are commonly used in dental composites and the effect of monomer functionality and molecular mass on the rate. Bis-GMA, TEGDMA, UDMA, MMA, HEMA, HPMA and different ratios of Bis-GMA/TEGDMA were mixed with Camphorquinone and Dimethyl aminoethyle methacrylate as initiator system. The shrinkage strain of the samples photopolymerised at Ca. 550 mW/cm2 and 23 degrees C was measured using the bonded-disk technique of Watts and Cash (Meas. Sci. Technol. 2 (1991) 788-794), and initial shrinkage-strain rates were obtained by numerical differentiation. Shrinkage-strain rates rose rapidly to a maximum, and then fell rapidly upon vitrification. Strain and initial strain rate were dependent upon monomer functionality, molecular mass and viscosity. Strain rates were correlated with Bis-GMA in Bis-GMA/TEGDMA mixtures up to 75-80 w/w%, due to the higher molecular mass of Bis-GMA affecting termination reactions, and then decreased due to its higher viscosity affecting propagation reactions. Monofunctional monomers exhibited lower rates. UDMA, a difunctional monomer of medium viscosity, showed the highest shrinkage strain rate (P < 0.05). Shrinkage strain rate, related to polymerization rate, is an important factor affecting the biomechanics and marginal integrity of composites cured in dental cavities. This study shows how this is related to monomer molecular structure and viscosity. The results are significant for the production, optimization and clinical application of dental composite restoratives.

Characterization of Cement Particles Found in Peri-implantitis-Affected Human Biopsy Specimens.

PubMed

Burbano, Maria; Wilson, Thomas G; Valderrama, Pilar; Blansett, Jonathan; Wadhwani, Chandur P K; Choudhary, Pankaj K; Rodriguez, Lucas C; Rodrigues, Danieli C

2015-01-01

Peri-implantitis is a disease characterized by soft tissue inflammation and continued loss of supporting bone, which can result in implant failure. Peri-implantitis is a multifactorial disease, and one of its triggering factors may be the presence of excess cement in the soft tissues surrounding an implant. This descriptive study evaluated the composition of foreign particles from 36 human biopsy specimens with 19 specimens selected for analysis. The biopsy specimens were obtained from soft tissues affected by peri-implantitis around cement-retained implant crowns and compared with the elemental composition of commercial luting cement. Nineteen biopsy specimens were chosen for the comparison, and five test cements (TempBond, Telio, Premier Implant Cement, Intermediate Restorative Material, and Relyx) were analyzed using scanning electron microscopy equipped with energy dispersive x-ray spectroscopy. This enabled the identification of the chemical composition of foreign particles embedded in the tissue specimens and the composition of the five cements. Statistical analysis was conducted using classification trees to pair the particles present in each specimen with the known cements. The particles in each biopsy specimen could be associated with one of the commercial cements with a level of probability ranging between .79 and 1. TempBond particles were found in one biopsy specimen, Telio particles in seven, Premier Implant Cement particles in four, Relyx particles in four, and Intermediate Restorative Material particles in three. Particles found in human soft tissue biopsy specimens around implants affected by peri-implant disease were associated with five commercially available dental cements.

Factors affecting the thermal shock behavior of yttria stabilized hafnia based graphite and tungsten composites.

NASA Technical Reports Server (NTRS)

Lineback, L. D.; Manning, C. R.

1971-01-01

Hafnia-based composites containing either graphite or tungsten were investigated as rocket nozzle throat inserts in solid propellant rocket engines. The thermal shock resistance of these materials is considered in terms of macroscopic thermal conductivity, thermal expansion, modulus of elasticity, and compressive fracture stress. The effect of degree of hafnia stabilization, density, and graphite or tungsten content upon these parameters is discussed. The variation of the ratio of elastic modulus to compressive fracture stress with density and its effect upon thermal shock resistance of these materials are discussed in detail.

Human genetic variation and the gut microbiome in disease.

PubMed

Hall, Andrew Brantley; Tolonen, Andrew C; Xavier, Ramnik J

2017-11-01

Taxonomic and functional changes to the composition of the gut microbiome have been implicated in multiple human diseases. Recent microbiome genome-wide association studies reveal that variants in many human genes involved in immunity and gut architecture are associated with an altered composition of the gut microbiome. Although many factors can affect the microbial organisms residing in the gut, a number of recent findings support the hypothesis that certain host genetic variants predispose an individual towards microbiome dysbiosis. This condition, in which the normal microbiome population structure is disturbed, is a key feature in disorders of metabolism and immunity.

The relations among child quality, family structure, and the value of the mother's time in Malaysia.

PubMed

Leppel, K

1982-10-01

A model of the determinants of child quality and of the value of a woman's time is developed and tested using data from the Malaysian Family Life Survey of 1976-1977. Child quality is measured by educational attainment; factors influencing the value of the mother's time include size and age composition of household, family income, education, and hours worked. The results indicate that size and age composition of household affect a woman's asking wage. However, more data are needed before the effects of family structure on schooling can be measured with confidence.

Effects of Plant Traits on Ecosystem and Regional Processes: a Conceptual Framework for Predicting the Consequences of Global Change

PubMed Central

CHAPIN, F. STUART

2003-01-01

Human activities are causing widespread changes in the species composition of natural and managed ecosystems, but the consequences of these changes are poorly understood. This paper presents a conceptual framework for predicting the ecosystem and regional consequences of changes in plant species composition. Changes in species composition have greatest ecological effects when they modify the ecological factors that directly control (and respond to) ecosystem processes. These interactive controls include: functional types of organisms present in the ecosystem; soil resources used by organisms to grow and reproduce; modulators such as microclimate that influence the activity of organisms; disturbance regime; and human activities. Plant traits related to size and growth rate are particularly important because they determine the productive capacity of vegetation and the rates of decomposition and nitrogen mineralization. Because the same plant traits affect most key processes in the cycling of carbon and nutrients, changes in plant traits tend to affect most biogeochemical cycling processes in parallel. Plant traits also have landscape and regional effects through their effects on water and energy exchange and disturbance regime. PMID:12588725

The role of climate and environmental variables in structuring bird assemblages in the Seasonally Dry Tropical Forests (SDTFs).

PubMed

Gonçalves, Gabriela Silva Ribeiro; Cerqueira, Pablo Vieira; Brasil, Leandro Schlemmer; Santos, Marcos Pérsio Dantas

2017-01-01

Understanding the processes that influence species diversity is still a challenge in ecological studies. However, there are two main theories to discuss this topic, the niche theory and the neutral theory. Our objective was to understand the importance of environmental and spatial processes in structuring bird communities within the hydrological seasons in dry forest areas in northeastern Brazil. The study was conducted in two National Parks, the Serra da Capivara and Serra das Confusões National Parks, where 36 areas were sampled in different seasons (dry, dry/rainy transition, rainy, rainy/dry transition), in 2012 and 2013. We found with our results that bird species richness is higher in the rainy season and lower during the dry season, indicating a strong influence of seasonality, a pattern also found for environmental heterogeneity. Richness was explained by local environmental factors, while species composition was explained by environmental and spatial factors. The environmental factors were more important in explaining variations in composition. Climate change predictions have currently pointed out frequent drought events and a rise in global temperature by 2050, which would lead to changes in species behavior and to increasing desertification in some regions, including the Caatinga. In addition, the high deforestation rates and the low level of representativeness of the Caatinga in the conservation units negatively affects bird communities. This scenario has demonstrated how climatic factors affect individuals, and, therefore, should be the starting point for conservation initiatives to be developed in xeric environments.

The role of climate and environmental variables in structuring bird assemblages in the Seasonally Dry Tropical Forests (SDTFs)

PubMed Central

Gonçalves, Gabriela Silva Ribeiro; Cerqueira, Pablo Vieira; Brasil, Leandro Schlemmer; Santos, Marcos Pérsio Dantas

2017-01-01

Understanding the processes that influence species diversity is still a challenge in ecological studies. However, there are two main theories to discuss this topic, the niche theory and the neutral theory. Our objective was to understand the importance of environmental and spatial processes in structuring bird communities within the hydrological seasons in dry forest areas in northeastern Brazil. The study was conducted in two National Parks, the Serra da Capivara and Serra das Confusões National Parks, where 36 areas were sampled in different seasons (dry, dry/rainy transition, rainy, rainy/dry transition), in 2012 and 2013. We found with our results that bird species richness is higher in the rainy season and lower during the dry season, indicating a strong influence of seasonality, a pattern also found for environmental heterogeneity. Richness was explained by local environmental factors, while species composition was explained by environmental and spatial factors. The environmental factors were more important in explaining variations in composition. Climate change predictions have currently pointed out frequent drought events and a rise in global temperature by 2050, which would lead to changes in species behavior and to increasing desertification in some regions, including the Caatinga. In addition, the high deforestation rates and the low level of representativeness of the Caatinga in the conservation units negatively affects bird communities. This scenario has demonstrated how climatic factors affect individuals, and, therefore, should be the starting point for conservation initiatives to be developed in xeric environments. PMID:28441412

Evaluation of nutritive quality of common carp, Cyprinus carpio L.

NASA Astrophysics Data System (ADS)

Ljubojević, D.; Đorđević, V.; Ćirković, M.

2017-09-01

Common carp is the most important commercial fish species in Serbia. This fish is a valuable source of nutritive components and plays a role in healthy human nutrition. This review evaluates the nutritive quality of common carp including proximate and fatty acid compositions as well as their effects on human health. The fat content and fatty acid composition of carp have been shown to vary due to different environmental factors and particularly due to nutrition. Technology of production and composition of planktonic and benthic organisms in fish ponds have been recognised as significant factors affecting carp meat quality and desirable chemical and fatty acid composition. Carp meat quality but also production parameters and fish health are positively influenced by a balanced feed mixture. Due to the low content of saturated fatty acids and cholesterol plus high levels of unsaturated fatty acids, common carp meat consumption could be linked with reduced risk of different heart diseases in humans. Also, fish proteins can have many beneficial roles in the preservation of human health. This paper emphasises the importance of consumption of common carp in order to prevent many diseases and preserve human health.

Bridge toughening in fiber-reinforced composites: A three-dimensional discrete fiber model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, K.X.; Huang, Y.; Chandra, A.

1995-07-01

The fracture behavior of unidirectionally fiber-reinforced composites is the principal focus of this paper. The model proposed here is three-dimensional and accounts for the effects of local fiber-crack interactions on spatial variations of crack tip behavior. The model also consistently accounts for the effect of composite anisotropy by embedding a penny-shaped crack in an orthotropic composite medium. Three factors are identified that influence the reductions of stress intensity factors (SIFS) due to fiber bridging: a dimensionless configuration constant, a fiber distribution pattern, and a fiber volume fraction. The model reveals that the fiber distribution pattern does not alter the spatialmore » mean of the SIFS, although it does affect the oscillational amplitude. The dimensionless configuration constant determines the extent of the bridging effect and provides guidance regarding possible avenues for enhancing bridge toughening. The design curve of SIFs (retarded by fiber bridging) vs the fiber volume fraction shows that the isotropic and orthotropic solutions differ just slightly from each other. However, the energy release rate obtained by an isotropic analysis (widely claimed to be the equivalent of SIFs in bridging models) could, significantly underestimate the bridging effect.« less

Fracture surface analysis in composite and titanium bonding

NASA Technical Reports Server (NTRS)

Devilbiss, T. A.; Wightman, J. P.

1985-01-01

To understand the mechanical properties of fiber-reinforced composite materials, it is necessary to understand the mechanical properties of the matrix materials and of the reinforcing fibers. Another factor that can affect the mechanical properties of a composite material is the interaction between the fiber and the matrix. In general, composites with strong fiber matrix bonding will give higher modulus, lower toughness composites. Composites with weak bonding will have a lower modulus and more ductility. The situation becomes a bit more complex when all possibilities are examined. To be considered are the following: the properties of the surface layer on the fiber, the interactive forces between polymer and matrix, the surface roughness and porosity of the fiber, and the morphology of the matrix polymer at the fiber surface. In practice, the surface of the fibers is treated to enhance the mechanical properties of a composite. These treatments include anodization, acid etching, high temperature oxidation, and plasma oxidation, to name a few. The goal is to be able to predict the surface properties of carbon fibers treated in various ways, and then to relate surface properties to fiber matrix bonding.

Body composition changes in pregnancy: measurement, predictors and outcomes

PubMed Central

Widen, EM; Gallagher, D

2014-01-01

Prevalence of overweight and obesity has risen in the United States over the past few decades. Concurrent with this rise in obesity has been an increase in pregravid body mass index and gestational weight gain affecting maternal body composition changes in pregnancy. During pregnancy, many of the assumptions inherent in body composition estimation are violated, particularly the hydration of fat-free mass, and available methods are unable to disentangle maternal composition from fetus and supporting tissues; therefore, estimates of maternal body composition during pregnancy are prone to error. Here we review commonly used and available methods for assessing body composition changes in pregnancy, including: (1) anthropometry, (2) total body water, (3) densitometry, (4) imaging, (5) dual-energy X-ray absorptiometry, (6) bioelectrical impedance and (7) ultrasound. Several of these methods can measure regional changes in adipose tissue; however, most of these methods provide only whole-body estimates of fat and fat-free mass. Consideration is given to factors that may influence changes in maternal body composition, as well as long-term maternal and offspring outcomes. Finally, we provide recommendations for future research in this area. PMID:24667754

Systematic review: body composition in adults with inflammatory bowel disease.

PubMed

Bryant, R V; Trott, M J; Bartholomeusz, F D; Andrews, J M

2013-08-01

There is a paucity of data on body composition in patients with inflammatory bowel disease (IBD). Alterations of fat and muscle may affect bone health, muscle performance, quality of life (QoL) and overall morbidity. To systematically review the literature on body composition in adults with IBD, and to discuss potential contributory factors and associations. A systematic search was performed in July 2012 of OVID SP MEDLINE, OVID EMBASE and National Library of Medicine's PubMed Central Medline (Limitations: English, humans, from 1992). A total of 19 articles comparing body composition in patients with IBD with healthy age- and sex-matched control populations were included in the primary analysis. A total of 631 patients with Crohn's disease (CD) and 295 with ulcerative colitis (UC), mean age 37.1 (s.d. ± 9.2) years; 485 (52%) female, were reported upon. Data were heterogeneous and methodology varied. Compared with controls, a statistically significant reduction in body mass index (BMI) was reported in 37% of CD and 20% of UC patients; reduced fat-free mass in 28% CD and 13% UC patients, and reduced fat mass in 31% CD and 13% UC patients. There was no consistent association between body composition and disease activity, duration, extent or therapies. BMI did not accurately predict body composition. Current data, although heterogeneous, suggest that many patients with IBD are affected by aberrations in fat and lean mass, which may not be detected during routine clinical assessment. The prevalence and impact of altered body composition amongst this population warrant further investigation. © 2013 John Wiley & Sons Ltd.

Life Course Influences on African American Men's Depression: Adolescent Parental Composition, Self-Concept, and Adult Earnings.

ERIC Educational Resources Information Center

Mizell, C. Andre

1999-01-01

Examines factors over the life course that affect levels of depression in Black men using samples of 892 African-American and 1,454 White men from the National Longitudinal Survey of Youth. Parental educational attainment is a significant negative predictor of depression. Its role and that of other identified predictors of depression are…

Regional and field-specific factors affect the composition of Fusarium head blight pathogens in subtropical no-till wheat agroecosystem of Brazil

USDA-ARS?s Scientific Manuscript database

A multiyear survey of >200 wheat fields in Paraná (PR) and Rio Grande do Sul (RS) states was conducted to assess the extent and distribution of Fusarium graminearum species complex (FGSC) diversity in the southern Brazilian wheat agroecosystem. Five species and three trichothecene genotypes were fou...

Propagation & Level: Factors Influencing in the ICT Composite Index at the School Level

ERIC Educational Resources Information Center

Aoki, Hiroyuki; Kim, JaMee; Lee, WonGyu

2013-01-01

Many nations are greatly affected by their education policies, and the educational level of different schools is relevant to a nation's ICT policy. In the area of ICT, Korea has achieved quite high levels of competency. This study analyzed the level of ICT competency of 4490 elementary and 2419 middle schools in Korea within the context of the…

Advanced Thermally Stable Coal-Derived Jet Fuels Compositional Factors Affecting Thermal Degradation of Jet Fuels

DTIC Science & Technology

1992-12-01

shown in Figure 4.2 and the peaks are identified and quantified in Table 4.2. Phenol and alkylphenols are the most readily visible 137 Cf) C-)" M0 oý...transformation of the catechol and alkylphenolic structures in subbituminous coal is a loss of aryl-( -containing structures and a condensation of the phenols

Effect of metallic silver nanoparticles on the alignment and relaxation behaviour of liquid crystalline material in smectic C* phase

NASA Astrophysics Data System (ADS)

Vimal, Tripti; Kumar Gupta, Swadesh; Katiyar, Rohit; Srivastava, Atul; Czerwinski, Michal; Krup, Katarzyna; Kumar, Sandeep; Manohar, Rajiv

2017-09-01

The influence of silver nanoparticles dispersed in a Ferroelectric Liquid Crystal (FLC) on the properties of the resultant composite system has been investigated by thermal, electro-optical, and dielectric methods. We show that the concentration of thiol capped silver nanoparticles is a critical factor in governing the alignment of nanoparticles (NPs) in the host FLC. The orientation of NPs in composite samples affects the ordering of the LC (Liquid Crystal) phase and consequently changes the various phase transition temperatures of the host LC. Formation of self-assembled 2D (two dimensional) arrays of nanoparticles is observed for high concentration of dopant in the LC, oriented perpendicular to the direction of rubbing. We propose that the molecular interaction between the thiol capped NPs and LC molecules is the key factor behind such an arrangement of NPs. Orientation of NPs has affected the relaxation behaviour and various other material parameters, significantly. A noteworthy change in DC conductivity articulates our proposed idea of the formation of 2D array of NPs perpendicular to the direction of rubbing. This comprehensive study endorses the importance of dopant concentration in modifying the properties of the host LC material.

Production of angiotensin I converting enzyme inhibitory (ACE-I) peptides during milk fermentation and their role in reducing hypertension.

PubMed

Rai, Amit Kumar; Sanjukta, Samurailatpam; Jeyaram, Kumaraswamy

2017-09-02

Fermented milk is a potential source of various biologically active peptides with specific health benefits. Angiotensin converting enzyme inhibitory (ACE-I) peptides are one of the most studied bioactive peptides produced during milk fermentation. The presence of these peptides is reported in various fermented milk products such as, yoghurt, cheese, sour milk, etc., which are also available as commercial products. Many of the ACE-I peptides formed during milk fermentation are resistant to gastrointestinal digestion and inhibit angiotensin converting enzyme (ACE) in the rennin angiotension system (RAS). There are various factors, which affect the formation ACE-I peptides and their ability to reach the target tissue in active form, which includes type of starters (lactic acid bacteria (LAB), yeast, etc.), substrate composition (casein type, whey protein, etc.), composition of ACE-I peptide, pre and post-fermentation treatments, and its stability during gastrointestinal digestion. The antihypertensive effect of fermented milk products has also been proved by various in vitro and in vivo (animal and human trials) experiments. This paper reviews the literature on fermented milk products as a source of ACE-I peptides and various factors affecting the production and activity of ACE-I peptides.

Adsorption of arsenic from aqueous solution using magnetic graphene oxide

NASA Astrophysics Data System (ADS)

Sherlala, A. I. A.; Raman, A. A.; Bello, M. M.

2017-06-01

A binary of graphene oxide (GO) and iron oxide (IO) was prepared and used for the removal of arsenic from aqueous solution. The synthesized compound was characterized using XRD analysis. The prepared composite was used for the adsorption of arsenic from aqueous solution. Central Composite Design was used to design the adsorption experiments and to investigate the effects of operational parameters (initial concentration of arsenic, adsorbent dosage, pH and time) on the adsorption capacity and efficiency. The adsorbent shows a high adsorption capacity for the arsenic. The adsorption efficiency ranges between 33.2 % and 99.95 %. The most significant factors affecting the adsorption capacity were found to be the initial concentration of arsenic and the adsorbent dosage. The initial pH of the solution slightly affects the adsorption capacity, with the maximum adsorption capacity occurring around pH 6 - 7. Thus, the developed adsorbent has a potential for effective removal of arsenic from aqueous solution.

Physical Nature of the Processes in Structure Forming, Phase and Chemical Composition of pipe Permanent Joints when MMA Welding

NASA Astrophysics Data System (ADS)

Il'yaschenko, D. P.; Chinakhov, D. A.; Danilov, V. I.; Sadykov, I. D.

2016-04-01

The paper outlines peculiarities of structure formation, phase and chemical composition in regard to heat content in molten electrode metal beads when pipe steel (steel 09G2S) welding using power sources with various energy characteristics. Mathematical calculations indicate an inverter power source provides minor heat content into the bead of electrode metal when welding. Experimental research has pointed at 4-9 % increase in impact strength of joints produced using an inverter power source in comparison with samples produced applying a diode rectifier. The following factors can possibly give rise to the increasing impact strength: difference in microstructures of weld joints, up to 50% shortening ferritic plates in metal of weld joint, change in dimensions of ferritic grains in the heat-affected zone by as much as 17.5 %, and decrease in the extent of heat-affected zone by 50%.

Spatial distribution of planktonic bacterial and archaeal communities in the upper section of the tidal reach in Yangtze River

PubMed Central

Fan, Limin; Song, Chao; Meng, Shunlong; Qiu, Liping; Zheng, Yao; Wu, Wei; Qu, Jianhong; Li, Dandan; Zhang, Cong; Hu, Gengdong; Chen, Jiazhang

2016-01-01

Bacterioplankton and archaeaplankton communities play key roles in the biogeochemical processes of water, and they may be affected by many factors. In this study, we used high-throughput 16S rRNA gene sequencing to profile planktonic bacterial and archaeal community compositions in the upper section of the tidal reach in Yangtze River. We found that the predominant bacterial phyla in this river section were Proteobacteria, Firmicutes, and Actinobacteria, whereas the predominant archaeal classes were Halobacteria, Methanomicrobia, and unclassified Euryarchaeota. Additionally, the bacterial and archaeal community compositions, richnesses, functional profiles, and ordinations were affected by the spatial heterogeneity related to the concentration changes of sulphate or nitrate. Notably, the bacterial community was more sensitive than the archaeal community to changes in the spatial characteristics of this river section. These findings provide important insights into the distributions of bacterial and archaeal communities in natural water habitats. PMID:27966673

Spatial distribution of planktonic bacterial and archaeal communities in the upper section of the tidal reach in Yangtze River

NASA Astrophysics Data System (ADS)

Fan, Limin; Song, Chao; Meng, Shunlong; Qiu, Liping; Zheng, Yao; Wu, Wei; Qu, Jianhong; Li, Dandan; Zhang, Cong; Hu, Gengdong; Chen, Jiazhang

2016-12-01

Bacterioplankton and archaeaplankton communities play key roles in the biogeochemical processes of water, and they may be affected by many factors. In this study, we used high-throughput 16S rRNA gene sequencing to profile planktonic bacterial and archaeal community compositions in the upper section of the tidal reach in Yangtze River. We found that the predominant bacterial phyla in this river section were Proteobacteria, Firmicutes, and Actinobacteria, whereas the predominant archaeal classes were Halobacteria, Methanomicrobia, and unclassified Euryarchaeota. Additionally, the bacterial and archaeal community compositions, richnesses, functional profiles, and ordinations were affected by the spatial heterogeneity related to the concentration changes of sulphate or nitrate. Notably, the bacterial community was more sensitive than the archaeal community to changes in the spatial characteristics of this river section. These findings provide important insights into the distributions of bacterial and archaeal communities in natural water habitats.

Ecosystem composition changes over the past millennium: model simulations and comparison with paleoecological observations

NASA Astrophysics Data System (ADS)

Liu, Y.; Rollinson, C.; Dietze, M.; McLachlan, J. S.; Poulter, B.; Quaife, T. L.; Raiho, A.; Ricciuto, D. M.; Schaefer, K. M.; Steinkamp, J.; Moore, D. J.

2015-12-01

Over multi-decadal to multi-centennial timescales, ecosystem function and carbon storage is largely influenced by vegetation composition. The predictability of ecosystem responses to climate change thus depends on the understanding of long-term community dynamics. Our study aims to quantify the influence of the most relevant ecological factors that control plant distribution and abundance, in contemporary terrestrial biosphere models and in paleo-records, and constrain the model processes and parameters with paleoecological data. We simulated vegetation changes at 6 sites in the northeastern United States over the past 1160 years using 7 terrestrial biosphere models and variations (CLM4.5-CN, ED2, ED2-LU, JULES-TRIFFID, LINKAGES, LPJ-GUESS, LPJ-wsl) driven by common paleoclimatic drivers. We examined plant growth, recruitment, and mortality (including other carbon turnover) of the plant functional types (PFTs) in the models, attributed the responses to three major factors (climate, competition, and disturbance), and estimated the relative effect of each factor. We assessed the model responses against plant-community theories (bioclimatic limits, niche difference, temporal variation and storage effect, and disturbance). We found that vegetation composition were sensitive to realized niche differences (e.g. differential growth response) among PFTs. Because many models assume unlimited dispersal and sometimes recruitment, the "storage effect" constantly affects community composition. Fire was important in determining the ecosystem composition, yet the vegetation to fire feedback was weak in the models. We also found that vegetation-composition changes in the simulations were driven to a much greater degree by growth as opposed to by turnover/mortality, when compared with those in paleoecological records. Our work suggest that 1) for forecasting slow changes in vegetation composition, we can use paleo-data to better quantify the realized niches of PFTs and associated uncertainties, and 2) for predicting abrupt changes in vegetation composition, we need to better implement processes of dynamic turnover and fire in current ecosystem models.

Breast Milk Transforming Growth Factor β Is Associated With Neonatal Gut Microbial Composition.

PubMed

Sitarik, Alexandra R; Bobbitt, Kevin R; Havstad, Suzanne L; Fujimura, Kei E; Levin, Albert M; Zoratti, Edward M; Kim, Haejin; Woodcroft, Kimberley J; Wegienka, Ganesa; Ownby, Dennis R; Joseph, Christine L M; Lynch, Susan V; Johnson, Christine C

2017-09-01

Breast milk is a complex bioactive fluid that varies across numerous maternal and environmental conditions. Although breast-feeding is known to affect neonatal gut microbiome, the milk components responsible for this effect are not well-characterized. Given the wide range of immunological activity breast milk cytokines engage in, we investigated 3 essential breast milk cytokines and their association with early life gut microbiota. A total of 52 maternal-child pairs were drawn from a racially diverse birth cohort based in Detroit, Michigan. Breast milk and neonatal stool specimens were collected at 1-month postpartum. Breast milk transforming growth factor (TGF)β1, TGFβ2, and IL-10 were assayed using enzyme-linked immunosorbent assays, whereas neonatal gut microbiome was profiled using 16S rRNA sequencing. Individually, immunomodulators TGFβ1 and TGFβ2 were significantly associated with neonatal gut microbial composition (R = 0.024, P = 0.041; R = 0.026, P = 0.012, respectively) and increased richness, evenness, and diversity, but IL-10 was not. The effects of TGFβ1 and TGFβ2, however, were not independent of one another, and the effect of TGFβ2 was stronger than that of TGFβ1. Higher levels of TGFβ2 were associated with the increased relative abundance of several bacteria, including members of Streptococcaceae and Ruminococcaceae, and lower relative abundance of distinct Staphylococcaceae taxa. Breast milk TGFβ concentration explains a portion of variability in gut bacterial microbiota composition among breast-fed neonates. Whether TGFβ acts in isolation or jointly with other bioactive components to alter bacterial composition requires further investigation. These findings contribute to an increased understanding of how breast-feeding affects the gut microbiome-and potentially immune development-in early life.

Influence of PP-g-MA compatibilizer characteristics on mechanical properties of glass fiber reinforced polypropylene composites

NASA Astrophysics Data System (ADS)

Guan, Zhuo

Glass fiber (GF) reinforced polypropylene (PP) has become a common composite material used for various applications. Previous reports indicated that grafting ratio and molecular weight (MW) of znaleic anhydride grafted polypropylene (PP-g-MA) are the two most significant factors affecting the mechanical properties of PP/PP-g-MA/GF composites, but the combined effect of these two factors remains controversial. The study of the importance of MA grafting ratio and MW is continued in this work using PPIPP-g MA/GF composites containing various grades and concentrations of PP-g MA compatibilizer. First, MFR and FT1R analyses were performed to characterize the physical and chemical properties- of each PP-g-MA resin. Then, premixed PP and PP-g-MA blend were compounded with GF via twin screw extrusion, with the compounds injection molded into tensile, flexural and Izod impact specimens (all ASTM standard) for mechanical properties testing. Generally speaking, at a given GF content, higher compatibilizer concentrations led to higher tensile, flexural and notched Izod impact strength up to an optimum MA concentrations above which these properties tended to level off PP-g-MA resins with higher grafting ratio were more efficient compatibilizers as indicated by improved tensile, flexural and impact properties at lower PP-g-MA contents. In addition, MW was expected to affect properties as well, with too high and too 16w MW values leading to reduced reinforcement. While the optimum MW values for tensile and impact strength were still not clear based on present results, the estimated optimum weight average MW for maximum flexural strength was 90,000 +/- 1,400 g/mol.

Impact of phenylalanine and urea applications to Tempranillo and Monastrell vineyards on grape amino acid content during two consecutive vintages.

PubMed

Garde-Cerdán, Teresa; Gutiérrez-Gamboa, Gastón; Portu, Javier; Fernández-Fernández, José Ignacio; Gil-Muñoz, Rocío

2017-12-01

Nitrogen plays a key role in the fermentation and secondary metabolites formation. The aim was to study the influence of vine nitrogen applications on grape amino acid composition. Nitrogen sources applied to Tempranillo and Monastrell grapevines were phenylalanine and urea, during two seasons. Results showed that the application of these compounds had little effect on grape amino acid composition, regardless of variety and vintage. This could be due to the fact that vineyards did not present nitrogenous requirements. Thus, variety was the determining factor in Asp, Glu, Gln, Cit, Met, Gly, Gaba, Val, Ile, and Leu while season was the factor that most affected Thr, Arg, Ala, and Lys due its implication on berry ripening. The concentration of the remaining amino acids was influenced by two or three of the factors studied. Therefore, when the vineyard has adequate nitrogen nutritional status, grape amino acid content was determined by variety and vintage. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bacterial growth, flow, and mixing shape human gut microbiota density and composition.

PubMed

Arnoldini, Markus; Cremer, Jonas; Hwa, Terence

2018-03-13

The human gut microbiota is highly dynamic, and host physiology and diet exert major influences on its composition. In our recent study, we integrated new quantitative measurements on bacterial growth physiology with a reanalysis of published data on human physiology to build a comprehensive modeling framework. This can generate predictions of how changes in different host factors influence microbiota composition. For instance, hydrodynamic forces in the colon, along with colonic water absorption that manifests as transit time, exert a major impact on microbiota density and composition. This can be mechanistically explained by their effect on colonic pH which directly affects microbiota competition for food. In this addendum, we describe the underlying analysis in more detail. In particular, we discuss the mixing dynamics of luminal content by wall contractions and its implications for bacterial growth and density, as well as the broader implications of our insights for the field of gut microbiota research.

Feminizing Wolbachia influence microbiota composition in the terrestrial isopod Armadillidium vulgare.

PubMed

Dittmer, Jessica; Bouchon, Didier

2018-05-03

Wolbachia are widespread heritable endosymbionts of arthropods notorious for their profound effects on host fitness as well as for providing protection against viruses and eukaryotic parasites, indicating that they can interact with other microorganisms sharing the same host environment. Using the terrestrial isopod crustacean Armadillidium vulgare, its highly diverse microbiota (>200 bacterial genera) and its three feminizing Wolbachia strains (wVulC, wVulM, wVulP) as a model system, the present study demonstrates that Wolbachia can even influence the composition of a diverse bacterial community under both laboratory and natural conditions. While host origin is the major determinant of the taxonomic composition of the microbiota in A. vulgare, Wolbachia infection affected both the presence and, more importantly, the abundance of many bacterial taxa within each host population, possibly due to competitive interactions. Moreover, different Wolbachia strains had different impacts on microbiota composition. As such, infection with wVulC affected a higher number of taxa than infection with wVulM, possibly due to intrinsic differences in virulence and titer between these two strains. In conclusion, this study shows that heritable endosymbionts such as Wolbachia can act as biotic factors shaping the microbiota of arthropods, with as yet unknown consequences on host fitness.

Long Term Positive Effect of Grassland Restoration on Plant Diversity - Success or Not?

PubMed Central

Lindborg, Regina

2016-01-01

Restoration is important for biodiversity conservation worldwide, but surprisingly little is known about its efficiency in a long-term perspective. In this study, we re-examined Swedish semi-natural grasslands 12–20 years after the restoration, by comparing field inventories of vascular plant species diversity made in 2001 with follow-up inventories in 2012. We also analysed restoration effect in relation to six environmental factors and used continuously managed semi-natural grasslands as references of desired state after restoration. We found that total species richness increased over time but not to reference levels, while there were no significant changes in species density or number of grassland specialists. However, the overall species composition in the restored sites, as well as grassland specialist composition, now largely resembled reference conditions. Fertilisation and time between abandonment and restoration were the only environmental variables that affected total species composition change, while site area affected change in grassland specialist composition. Our results show that restoration of semi-natural grasslands can contribute to conservation of semi-natural habitats and their associated biodiversity. Yet, due to the vague restoration goals for these sites, it is difficult to evaluate the restoration success, which emphasise the general need for clear and measurable goals. PMID:27196748

Plant growth, nutrients and potentially toxic elements in leaves of yerba mate clones in response to phosphorus in acid soils.

PubMed

Barbosa, Julierme Z; Motta, Antonio C V; Consalter, Rangel; Poggere, Giovana C; Santin, Delmar; Wendling, Ivar

2018-01-01

Native to subtropical region of South America, yerba mate is responsive to P under some conditions, but the degree of influence of genetic and soil on the growth and composition of the leaf is unknown. The aim of study was to evaluate plant growth, nutrients and potentially toxic elements in leaves of yerba mate clones in response to P application in acid soils. In greenhouse condition, two yerba mate clone seedlings were grown (210 days) in pots, each clone in a completely randomized design in factorial scheme (with and without P; four acid soils). The elemental composition of leaves and the growth of plants were determined. Phosphorus promoted plant growth, but this was not accompanied by increased P in leaf tissue in all conditions tested. The P effect on the elemental composition varied: decrease/null (N, K, Mg, Mn, Cu, Ni, B, Mo, Al, Cd); increase/null (C/N, C, Ca, Fe, V); increase/decrease/null (Zn, Ba, Pb) and; null (Cr). The soils affect the elemental composition of the leaves, especially Mn, with accumulation greater than 1000 mg kg-1. The Ba, Pb, Al and Zn in the leaves varied among clones. Yerba mate response to P was affected by edaphic and plant factors.

Long Term Positive Effect of Grassland Restoration on Plant Diversity - Success or Not?

PubMed

Waldén, Emelie; Lindborg, Regina

2016-01-01

Restoration is important for biodiversity conservation worldwide, but surprisingly little is known about its efficiency in a long-term perspective. In this study, we re-examined Swedish semi-natural grasslands 12-20 years after the restoration, by comparing field inventories of vascular plant species diversity made in 2001 with follow-up inventories in 2012. We also analysed restoration effect in relation to six environmental factors and used continuously managed semi-natural grasslands as references of desired state after restoration. We found that total species richness increased over time but not to reference levels, while there were no significant changes in species density or number of grassland specialists. However, the overall species composition in the restored sites, as well as grassland specialist composition, now largely resembled reference conditions. Fertilisation and time between abandonment and restoration were the only environmental variables that affected total species composition change, while site area affected change in grassland specialist composition. Our results show that restoration of semi-natural grasslands can contribute to conservation of semi-natural habitats and their associated biodiversity. Yet, due to the vague restoration goals for these sites, it is difficult to evaluate the restoration success, which emphasise the general need for clear and measurable goals.

Experimental observations and finite element analysis of the initiation of fiber microbuckling in notched composite laminates

NASA Technical Reports Server (NTRS)

Guynn, E. Gail; Bradley, Walter L.

1989-01-01

An understanding was developed of the factors that determine the semi-circular edge-notched compressive strength and the associated failure mode(s) were identified of thermoplastic composite laminates with multidirectional stacking sequences. The experimental observations and the detailed literature review suggest at least four factors that affected the determination of the strain levels at which fiber microbuckling initiates and thus, partially control the composite's compression strength. The dependent variables studied are the compressive strength of a reduced gage section compression specimen and the compression strength of a compression specimen with two semi-circular edge notches (no opposite free edges) centered along the gage section. In this research, specimens containing two semi-circular edge notches (no opposite free edges) were loaded in compression at a relatively slow rate to provide more stable development of fiber microbuckling damage. The results indicate that the local constraints (free surfaces, supporting ply orientation, and resin-rich regions) significantly affect the strain level for the initiation of in-plane fiber microbuckling. Preliminary results at an elevated temperature, 77 C, showed the shear stress yield strength of the resin was reduced and consequently, the resistance to fiber microbuckling was also reduced. The finite element analysis of the perfectly straight fiber problem indicates that the free surface effect causes a 10 percent reduction in the critical buckling strain. However, the experimentally measured reduction for fibers with an initial fiber curvature, was 35 percent.

Critical Heat Flux in Pool Boiling on Metal-Graphite Composite Surfaces

NASA Technical Reports Server (NTRS)

Zhang, Nengli; Yang, Wen-Jei; Chao, David F.; Chao, David F. (Technical Monitor)

2000-01-01

A study is conducted on high heat-flux pool boiling of pentane on micro-configured composite surfaces. The boiling surfaces are copper-graphite (Cu-Gr) and aluminum-graphite (Al-Gr) composites with a fiber volume concentration of 50%. The micro-graphite fibers embedded in the matrix contribute to a substantial enhancement in boiling heat-transfer performance. Correlation equations are obtained for both the isolated and coalesced bubble regimes, utilizing a mathematical model based on a metal-graphite, two-tier configuration with the aid of experimental data. A new model to predict the critical heat flux (CHF) on the composites is proposed to explain the fundamental aspects of the boiling phenomena. Three different factors affecting the CHF are considered in the model. Two of them are expected to become the main agents driving vapor volume detachment under microgravity conditions, using the metal-graphite composite surfaces as the heating surface and using liquids with an unusual Marangoni effect as the working fluid.

High-efficiency AlxGa1-xAs/GaAs cathode for photon-enhanced thermionic emission solar energy converters

NASA Astrophysics Data System (ADS)

Feng, Cheng; Zhang, Yijun; Qian, Yunsheng; Wang, Ziheng; Liu, Jian; Chang, Benkang; Shi, Feng; Jiao, Gangcheng

2018-04-01

A theoretical emission model for AlxGa1-xAs/GaAs cathode with complex structure based on photon-enhanced thermionic emission is developed by utilizing one-dimensional steady-state continuity equations. The cathode structure comprises a graded-composition AlxGa1-xAs window layer and an exponential-doping GaAs absorber layer. In the deduced model, the physical properties changing with the Al composition are taken into consideration. Simulated current-voltage characteristics are presented and some important factors affecting the conversion efficiency are also illustrated. Compared with the graded-composition and uniform-doping cathode structure, and the uniform-composition and uniform-doping cathode structure, the graded-composition and exponential-doping cathode structure can effectively improve the conversion efficiency, which is ascribed to the twofold built-in electric fields. More strikingly, this graded bandgap structure is especially suitable for photon-enhanced thermionic emission devices since a higher conversion efficiency can be achieved at a lower temperature.

Photochemical decoration of magnetic composites with silver nanostructures for determination of creatinine in urine by surface-enhanced Raman spectroscopy.

PubMed

Alula, Melisew Tadele; Yang, Jyisy

2014-12-01

In this study, silver nanostructures decorated magnetic nanoparticles for surface-enhanced Raman scattering (SERS) measurements were prepared via photoreduction utilizing the catalytic activity of ZnO nanostructure. The ZnO/Fe3O4 composite was first prepared by dispersing pre-formed magnetic nanoparticles into alkaline zinc nitrate solutions. After annealing of the precipitates, the formed ZnO/Fe3O4 composites were successfully decorated with silver nanostructures by soaking the composites into silver nitrate/ethylene glycol solution following UV irradiations. To find the optimal condition when preparing Ag@ZnO/Fe3O4 composites for SERS measurements, factors such as the reaction conditions, photoreduction time, concentration of zinc nitrate and silver nitrate were studied. Results indicated that the photoreduction efficiency was significantly improved with the assistance of ZnO but the amount of ZnO in the composite is not critical. The concentration of silver nitrate and UV irradiation time affected the morphologies of the formed composites and optimal condition in preparation of the composites for SERS measurement was found using 20mM of silver nitrate with an irradiation time of 90 min. Under the optimized condition, the obtained SERS intensities were highly reproducible with a SERS enhancement factor in the order of 7. Quantitative analyses showed that a linear range up to 1 µM with a detection limit lower than 0.1 µM in the detection of creatinine in aqueous solution could be obtained. Successful applying of these prepared composites to determine creatinine in urine sample was obtained. Copyright © 2014 Elsevier B.V. All rights reserved.

Host and Environmental Factors Affecting the Intestinal Microbiota in Chickens

PubMed Central

Kers, Jannigje G.; Velkers, Francisca C.; Fischer, Egil A. J.; Hermes, Gerben D. A.; Stegeman, J. A.; Smidt, Hauke

2018-01-01

The initial development of intestinal microbiota in poultry plays an important role in production performance, overall health and resistance against microbial infections. Multiplexed sequencing of 16S ribosomal RNA gene amplicons is often used in studies, such as feed intervention or antimicrobial drug trials, to determine corresponding effects on the composition of intestinal microbiota. However, considerable variation of intestinal microbiota composition has been observed both within and across studies. Such variation may in part be attributed to technical factors, such as sampling procedures, sample storage, DNA extraction, the choice of PCR primers and corresponding region to be sequenced, and the sequencing platforms used. Furthermore, part of this variation in microbiota composition may also be explained by different host characteristics and environmental factors. To facilitate the improvement of design, reproducibility and interpretation of poultry microbiota studies, we have reviewed the literature on confounding factors influencing the observed intestinal microbiota in chickens. First, it has been identified that host-related factors, such as age, sex, and breed, have a large effect on intestinal microbiota. The diversity of chicken intestinal microbiota tends to increase most during the first weeks of life, and corresponding colonization patterns seem to differ between layer- and meat-type chickens. Second, it has been found that environmental factors, such as biosecurity level, housing, litter, feed access and climate also have an effect on the composition of the intestinal microbiota. As microbiota studies have to deal with many of these unknown or hidden host and environmental variables, the choice of study designs can have a great impact on study outcomes and interpretation of the data. Providing details on a broad range of host and environmental factors in articles and sequence data repositories is highly recommended. This creates opportunities to combine data from different studies for meta-analysis, which will facilitate scientific breakthroughs toward nutritional and husbandry associated strategies to improve animal health and performance. PMID:29503637

Host and Environmental Factors Affecting the Intestinal Microbiota in Chickens.

PubMed

Kers, Jannigje G; Velkers, Francisca C; Fischer, Egil A J; Hermes, Gerben D A; Stegeman, J A; Smidt, Hauke

2018-01-01

The initial development of intestinal microbiota in poultry plays an important role in production performance, overall health and resistance against microbial infections. Multiplexed sequencing of 16S ribosomal RNA gene amplicons is often used in studies, such as feed intervention or antimicrobial drug trials, to determine corresponding effects on the composition of intestinal microbiota. However, considerable variation of intestinal microbiota composition has been observed both within and across studies. Such variation may in part be attributed to technical factors, such as sampling procedures, sample storage, DNA extraction, the choice of PCR primers and corresponding region to be sequenced, and the sequencing platforms used. Furthermore, part of this variation in microbiota composition may also be explained by different host characteristics and environmental factors. To facilitate the improvement of design, reproducibility and interpretation of poultry microbiota studies, we have reviewed the literature on confounding factors influencing the observed intestinal microbiota in chickens. First, it has been identified that host-related factors, such as age, sex, and breed, have a large effect on intestinal microbiota. The diversity of chicken intestinal microbiota tends to increase most during the first weeks of life, and corresponding colonization patterns seem to differ between layer- and meat-type chickens. Second, it has been found that environmental factors, such as biosecurity level, housing, litter, feed access and climate also have an effect on the composition of the intestinal microbiota. As microbiota studies have to deal with many of these unknown or hidden host and environmental variables, the choice of study designs can have a great impact on study outcomes and interpretation of the data. Providing details on a broad range of host and environmental factors in articles and sequence data repositories is highly recommended. This creates opportunities to combine data from different studies for meta-analysis, which will facilitate scientific breakthroughs toward nutritional and husbandry associated strategies to improve animal health and performance.

Calculations of hydrogen diffusivity in Zr-based alloys: Influence of alloying elements and effect of stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, J.; Jiang, C.; Zhang, Y.

This report summarizes the progress on modeling hydrogen diffusivity in Zr-based alloys. The presence of hydrogen (H) can detrimentally affect the mechanical properties of many metals and alloys. To mitigate these detrimental effects requires fundamental understanding of the thermodynamics and kinetics governing H pickup and hydride formation. In this work, we focus on H diffusion in Zr-based alloys by studying the effects of alloying elements and stress, factors that have been shown to strongly affect H pickup and hydride formation in nuclear fuel claddings. A recently developed accelerated kinetic Monte Carlo method is used for the study. It is foundmore » that for the alloys considered here, H diffusivity depends weakly on composition, with negligible effect at high temperatures in the range of 600-1200 K. Therefore, the small variation in compositions of these alloys is likely not a major cause of the very different H pickup rates. In contrast, stress strongly affects H diffusivity. This effect needs to be considered for studying hydride formation and delayed hydride cracking.« less

Effects of growing conditions on purple corncob (Zea mays L.) anthocyanins.

PubMed

Jing, Pu; Noriega, Victor; Schwartz, Steven J; Giusti, M Mónica

2007-10-17

Purple corn ( Zea mays L.) has been used for centuries as a natural food colorant in South America and, more recently, in Asia and Europe. However, limited information is available on the factors affecting their anthocyanin concentration and profiles. In this study, 18 purple corn samples grown under different conditions in Peru were evaluated for quantitative and qualitative anthocyanin composition as well as total phenolics. High variability was observed on monomeric anthocyanin and phenolic contents with yields ranging from 290 to 1333 mg/100 g dry weight (DW) and from 950 to 3516 mg/100 g DW, respectively, while 30.5-47.1% of the total phenolics were anthocyanins. The major anthocyanins present were cyanidin-3-glucoside, pelargonidin-3-glucoside, peonidin-3-glucoside, cyanidin-3-maloylglucoside, pelargonidin-3-maloylglucoside, and peonidin-3-maloylglucoside, and 35.6-54.0% of the anthocyanins were acylated. Potassium sources/concentrations on the soil and seedling density did not significantly affect anthocyanin composition. The growing location affected anthocyanin levels and the percentage of anthocyanins to total phenolics ( p < 0.01) and should be taken into account when choosing a material for color production.

Lignin biosynthesis perturbations affect secondary cell wall composition and saccharification yield in Arabidopsis thaliana

PubMed Central

2013-01-01

Background Second-generation biofuels are generally produced from the polysaccharides in the lignocellulosic plant biomass, mainly cellulose. However, because cellulose is embedded in a matrix of other polysaccharides and lignin, its hydrolysis into the fermentable glucose is hampered. The senesced inflorescence stems of a set of 20 Arabidopsis thaliana mutants in 10 different genes of the lignin biosynthetic pathway were analyzed for cell wall composition and saccharification yield. Saccharification models were built to elucidate which cell wall parameters played a role in cell wall recalcitrance. Results Although lignin is a key polymer providing the strength necessary for the plant’s ability to grow upward, a reduction in lignin content down to 64% of the wild-type level in Arabidopsis was tolerated without any obvious growth penalty. In contrast to common perception, we found that a reduction in lignin was not compensated for by an increase in cellulose, but rather by an increase in matrix polysaccharides. In most lignin mutants, the saccharification yield was improved by up to 88% cellulose conversion for the cinnamoyl-coenzyme A reductase1 mutants under pretreatment conditions, whereas the wild-type cellulose conversion only reached 18%. The saccharification models and Pearson correlation matrix revealed that the lignin content was the main factor determining the saccharification yield. However, also lignin composition, matrix polysaccharide content and composition, and, especially, the xylose, galactose, and arabinose contents influenced the saccharification yield. Strikingly, cellulose content did not significantly affect saccharification yield. Conclusions Although the lignin content had the main effect on saccharification, also other cell wall factors could be engineered to potentially increase the cell wall processability, such as the galactose content. Our results contribute to a better understanding of the effect of lignin perturbations on plant cell wall composition and its influence on saccharification yield, and provide new potential targets for genetic improvement. PMID:23622268

Aquatic community structure in Mediterranean edge-of-field waterbodies as explained by environmental factors and the presence of pesticide mixtures.

PubMed

Pereira, Ana Santos; Dâmaso-Rodrigues, Maria Luísa; Amorim, Ana; Daam, Michiel A; Cerejeira, Maria José

2018-06-16

Studies addressing the predicted effects of pesticides in combination with abiotic and biotic factors on aquatic biota in ditches associated with typical Mediterranean agroecosystems are scarce. The current study aimed to evaluate the predicted effects of pesticides along with environmental factors and biota interactions on macroinvertebrate, zooplankton and phytoplankton community compositions in ditches adjacent to Portuguese maize and tomato crop areas. Data was analysed with the variance partitioning procedure based on redundancy analysis (RDA). The total variance in biological community composition was divided into the variance explained by the multi-substance potentially affected fraction [(msPAF) arthropods and primary producers], environmental factors (water chemistry parameters), biotic interactions, shared variance, and unexplained variance. The total explained variance reached 39.4% and the largest proportion of this explained variance was attributed to msPAF (23.7%). When each group (phytoplankton, zooplankton and macroinvertebrates) was analysed separately, biota interactions and environmental factors explained the largest proportion of variance. Results of this study indicate that besides the presence of pesticide mixtures, environmental factors and biotic interactions also considerably influence field freshwater communities. Subsequently, to increase our understanding of the risk of pesticide mixtures on ecosystem communities in edge-of-field water bodies, variations in environmental and biological factors should also be considered.

Elemental, isotopic and molecular abundances in comets

NASA Technical Reports Server (NTRS)

Delsemme, A. H.

1986-01-01

The chemical composition of comet nuclei and the factors affecting it are discussed, summarizing the results of recent theoretical, experimental, and observational investigations. Consideration is given to the evidence supporting the view that the nucleus is radially differentiation (except for a thin outer layer), surface differentiation by heat processing and outgassing, and mantle buildup on an undifferentiated core. The nature of the refractory and volatile components is examined, and the elemental and isotopic compositions are given in tables and characterized. The uncertain (except for H2O) molecular composition of the volatile fraction is considered, and it is suggested that some oxides or aldehydes (such as CO, CO2, and H2CO), but no large amounts of fully hydrogenated compounds (such as CH4 and NH3) are included.

Predicting patriarchy: using individual and contextual factors to examine patriarchal endorsement in communities.

PubMed

Crittenden, Courtney A; Wright, Emily M

2013-04-01

In much feminist literature, patriarchy has often been studied as a predictive variable for attitudes toward or acts of violence against women. However, rarely has patriarchy been examined as an outcome across studies. The current study works toward filling this gap by examining several individual-and neighborhood-level factors that might influence patriarchy. Specifically, this research seeks to determine if neighborhood-level attributes related to socioeconomic status, family composition, and demographic information affect patriarchal views after individual-level correlates of patriarchy were controlled. Findings suggest that factors at both the individual- and neighborhood levels, particularly familial characteristics and dynamics, do influence the endorsement of patriarchal views.

Cartilage tissue engineering: recent advances and perspectives from gene regulation/therapy.

PubMed

Li, Kuei-Chang; Hu, Yu-Chen

2015-05-01

Diseases in articular cartilages affect millions of people. Despite the relatively simple biochemical and cellular composition of articular cartilages, the self-repair ability of cartilage is limited. Successful cartilage tissue engineering requires intricately coordinated interactions between matrerials, cells, biological factors, and phycial/mechanical factors, and still faces a multitude of challenges. This article presents an overview of the cartilage biology, current treatments, recent advances in the materials, biological factors, and cells used in cartilage tissue engineering/regeneration, with strong emphasis on the perspectives of gene regulation (e.g., microRNA) and gene therapy. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Review of the inorganic geochemistry of peats and peatland waters

NASA Astrophysics Data System (ADS)

Shotyk, William

1988-06-01

The major floristic and geochemical differences between bogs, fens, and swamps are summarized, and the most common peat types described. This is followed by a critical, historical review of the literature. The methods used to measure the pH of peatland (mire) waters are examined, and the pH range of various peatland types is reported. In addition, horizontal and vertical pH variations are illustrated, and factors affecting the pH of these waters reviewed. The cause of the low pH of surface waters of Sphagnum bogs (approximately pH 4) is critically investigated, and the relative importance of dissolved CO 2 and other inorganic acids, and organic acids to the low pH is assessed. Cation exchange on the surfaces of Sphagnum mosses is found to be a relatively unimportant acidification mechanism, but important to the chemical ecology of the plants. The redox chemistry of mire waters is described in terms of the geochemistry of such redox indicators as O 2, CO 2, CH 4, CO, H 2, H 2S, SO 42-, native Cu, and siderite (FeCO 3). Published studies of Eh in peatlands are cited, and the problems of Eh measurement and interpretation are explored. The chemical composition of mire waters (major and trace metals, and nonmetallic species) is examined, and factors affecting their composition reported. The abundance and distribution of mineral matter in peats is described, and the occurrence and formation of minerals of Fe (pyrite and other sulphides, siderite, vivianite), Cu (chalcopyrite, native Cu, covellite) and Zn (smithsonite and wurtzite) investigated. The abundance and distribution of major elements (Si, Al, Na, K, Mg, Ca) and trace metals (Ni, V, Cr, Fe, Mn, Cu, U, Zn, Pb) is described, and factors affecting their solubility examined.

A Greenhouse Assay on the Effect of Applied Urea Amount on the Rhizospheric Soil Bacterial Communities.

PubMed

Shang, Shuanghua; Yi, Yanli

2015-12-01

The rhizospheric bacteria play key role in plant nutrition and growth promotion. The effects of increased nitrogen inputs on plant rhizospheric soils also have impacted on whole soil microbial communities. In this study, we analyzed the effects of applied nitrogen (urea) on rhizospheric bacterial composition and diversity in a greenhouse assay using the high-throughput sequencing technique. To explore the environmental factors driving the abundance, diversity and composition of soil bacterial communities, the relationship between soil variables and the bacterial communities were also analyzed using the mantel test as well as the redundancy analysis. The results revealed significant bacterial diversity changes at different amounts of applied urea, especially between the control treatment and the N fertilized treatments. Mantel tests showed that the bacterial communities were significantly correlated with the soil nitrate nitrogen, available nitrogen, soil pH, ammonium nitrogen and total organic carbon. The present study deepened the understanding about the rhizospheric soil microbial communities under different amounts of applied urea in greenhouse conditions, and our work revealed the environmental factors affecting the abundance, diversity and composition of rhizospheric bacterial communities.

Site occupancy, composition and magnetic structure dependencies of martensitic transformation in Mn2Ni1 + x Sn1-x.

PubMed

Kundu, Ashis; Ghosh, Subhradip

2017-11-29

A delicate balance between various factors such as site occupancy, composition and magnetic ordering seems to affect the stability of the martensitic phase in [Formula: see text] [Formula: see text] [Formula: see text]. Using first-principles DFT calculations, we explore the impacts of each one of these factors on the martensitic stability of this system. Our results on total energies, magnetic moments and electronic structures upon changes in the composition, the magnetic configurations and the site occupancies show that the occupancies at the 4d sites in the inverse Heusler crystal structure play the most crucial role. The presence of Mn at the 4d sites originally occupied by Sn and its interaction with the Mn atoms at other sites decide the stability of the martensitic phases. This explains the discrepancy between the experiments and earlier DFT calculations regarding phase stability in [Formula: see text]NiSn. Our results qualitatively explain the trends observed experimentally with regard to martensitic phase stability and the magnetisations in Ni-excess, Sn-deficient [Formula: see text]NiSn system.

Cultivar and Year Rather than Agricultural Practices Affect Primary and Secondary Metabolites in Apple Fruit

PubMed Central

Renard, Catherine M. G. C.; Plenet, Daniel; Gautier, Hélène; Touloumet, Line; Girard, Thierry; Simon, Sylvaine

2015-01-01

Many biotic and abiotic parameters affect the metabolites involved in the organoleptic and health value of fruits. It is therefore important to understand how the growers' decisions for cultivar and orchard management can affect the fruit composition. Practices, cultivars and/or year all might participate to determine fruit composition. To hierarchize these factors, fruit weight, dry matter, soluble solids contents, titratable acidity, individual sugars and organics acids, and phenolics were measured in three apple cultivars (‘Ariane’, ‘Melrose’ and ‘Smoothee’) managed under organic, low-input and conventional management. Apples were harvested at commercial maturity in the orchards of the cropping system experiment BioREco at INRA Gotheron (Drôme, 26) over the course of three years (2011, 2012 and 2013). The main factors affecting primary and secondary metabolites, in both apple skin and flesh, were by far the cultivar and the yearly conditions, while the management system had a very limited effect. When considering the three cultivars and the year 2011 to investigate the effect of the management system per se, only few compounds differed significantly between the three systems and in particular the total phenolic content did not differ significantly between systems. Finally, when considering orchards grown in the same pedoclimatic conditions and of the same age, instead of the usual organic vs. conventional comparison, the effect of the management system on the apple fruit quality (Fruit weight, dry matter, soluble solids content, titratable acidity, individual sugars, organic acids, and phenolics) was very limited to non-significant. The main factors of variation were the cultivar and the year of cropping rather than the cropping system. More generally, as each management system (e.g. conventional, organic…) encompasses a great variability of practices, this highlights the importance of accurately documenting orchard practices and design beside the generic type of management in such studies. PMID:26618711

Bone density in the obese child - clinical considerations and diagnostic challenges

PubMed Central

Kelley, Jennifer; Crabtree, Nicola; Zemel, Babette S.

2017-01-01

The prevalence of obesity in children has reached epidemic proportions. Concern about bone health in obese children, in part, derives from the potentially increased fracture risk associated with obesity. Additional risk factors that affect bone mineral accretion, may also contribute to obesity, such as low physical activity and nutritional factors. Consequences of obesity, such as inflammation, insulin resistance and non-alcoholic fatty liver disease, may also affect bone mineral acquisition, especially during the adolescent years when rapid increases in bone contribute to attaining peak bone mass. Further, numerous pediatric health conditions are associated with excess adiposity, altered body composition or endocrine disturbances that can affect bone accretion. Thus, there is a multitude of reasons for considering clinical assessment of bone health in an obese child. Multiple diagnostic challenges affect the measurement of bone density and its interpretation. These include greater precision error, difficulty in positioning, and the effects of increased lean and fat tissue on bone health outcomes. Future research is required to address these issues to improve bone health assessment in obese children. PMID:28105511

Role of interfacial thermal barrier in the transverse thermal conductivity of uniaxial SiC fiber-reinforced reaction bonded silicon nitride

NASA Technical Reports Server (NTRS)

Bhatt, H.; Donaldson, K. Y.; Hasselman, D. P. H.; Bhatt, R. T.

1992-01-01

The transverse thermal conductivity of reaction-bonded Si3N4 is significantly affected by an interfacial barrier at the interface formed with SiC reinforcing fibers. A comparative study of composites with and without reinforcing-fiber carbon coatings found the coating to reduce effective thermal conductivity by a factor of about 2; this, however, is partially due to a thermal expansion-mismatch gap between fiber and matrix. HIPing of composites with coated fibers led to an enhancement of thermal conductivity via improved interfacial thermal contact and greater grain size and crystallinity of the fibers.

Does graded reaming affect the composition of reaming products in intramedullary nailing of long bones?

PubMed

Kouzelis, Antonis Th; Kourea, Helen; Megas, Panagiotis; Panagiotopoulos, Elias; Marangos, Markos; Lambiris, Elias

2004-08-01

Reaming products taken during intramedullary nailing were examined to identify possible differences in their composition depending on the reaming percentage. Reaming products were taken from 39 fresh closed tibial and femoral diaphyseal fractures in patients with an average age of 29 years. According to histology, reaming products mainly consisted of bone trabeculae, viable or nonviable, and bone marrow stroma. A statistically significant reverse correlation exists between viable bone mass percentage and reaming progress. Reaming 1 mm less than the minimum canal diameter provides a higher viable bone mass percentage, which might be an important factor in the bone healing process.

Multi-Scale Modeling of an Integrated 3D Braided Composite with Applications to Helicopter Arm

NASA Astrophysics Data System (ADS)

Zhang, Diantang; Chen, Li; Sun, Ying; Zhang, Yifan; Qian, Kun

2017-10-01

A study is conducted with the aim of developing multi-scale analytical method for designing the composite helicopter arm with three-dimensional (3D) five-directional braided structure. Based on the analysis of 3D braided microstructure, the multi-scale finite element modeling is developed. Finite element analysis on the load capacity of 3D five-directional braided composites helicopter arm is carried out using the software ABAQUS/Standard. The influences of the braiding angle and loading condition on the stress and strain distribution of the helicopter arm are simulated. The results show that the proposed multi-scale method is capable of accurately predicting the mechanical properties of 3D braided composites, validated by the comparison the stress-strain curves of meso-scale RVCs. Furthermore, it is found that the braiding angle is an important factor affecting the mechanical properties of 3D five-directional braided composite helicopter arm. Based on the optimized structure parameters, the nearly net-shaped composite helicopter arm is fabricated using a novel resin transfer mould (RTM) process.

Carbon dioxide adsorption on micro-mesoporous composite materials of ZSM-12/MCM-48 type: The role of the contents of zeolite and functionalized amine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santos, S.C.G.; Pedrosa, A.M.Garrido; Souza, M.J.B., E-mail: mjbsufs@gmail.com

2015-10-15

Highlights: • Synthesis of the micro-mesoporous composite materials of ZSM-12/MCM-48 type. • Application of these adsorbents in the carbon dioxide adsorption. • Effects of the contents of zeolite and amino group in the material surface on the CO{sub 2} capture efficiency. - Abstract: In this study ZSM-12/MCM-48 adsorbents have been synthesized at three ZSM-12 content, and also were functionalizated with amine groups by grafting. All the adsorbents synthesized were evaluated for CO{sub 2} capture. The X-ray diffraction analysis of the ZSM-12/MCM-48 composite showed the main characteristic peaks of ZSM-12 and MCM-48, and after the functionalization, the structure of MCM-48 onmore » the composite impregnated was affected due amine presence. For the composites without amine, the ZSM-12 content was the factor determining in the adsorption capacity of CO{sub 2} and for the composites with amine the amount of amine was that influenced in the adsorption capacity.« less

Fitting in to Move Forward: How Belonging Affects Women in Physics

NASA Astrophysics Data System (ADS)

Ito, Tiffany

2017-01-01

This talk will consider different factors that have been shown to negatively affect women in physics and other STEM fields by decreasing their subjective sense of belonging, fit, and acceptance. I will discuss recent studies documenting gender disparities in belonging and the negative effect this has on women's persistence. I will also consider the effects of gender composition within group problem-solving tasks on women's belonging, behavior, and perceived competency. Finally, I will discuss potential interventions and changes in classroom context that may serve to encourage women and members of other underrepresented groups.

Frequencies of polymorphisms associated with BSE resistance differ significantly between Bos taurus, Bos indicus, and composite cattle

PubMed Central

Brunelle, Brian W; Greenlee, Justin J; Seabury, Christopher M; Brown, Charles E; Nicholson, Eric M

2008-01-01

Background Transmissible spongiform encephalopathies (TSEs) are neurodegenerative diseases that affect several mammalian species. At least three factors related to the host prion protein are known to modulate susceptibility or resistance to a TSE: amino acid sequence, atypical number of octapeptide repeats, and expression level. These factors have been extensively studied in breeds of Bos taurus cattle in relation to classical bovine spongiform encephalopathy (BSE). However, little is currently known about these factors in Bos indicus purebred or B. indicus × B. taurus composite cattle. The goal of our study was to establish the frequency of markers associated with enhanced susceptibility or resistance to classical BSE in B. indicus purebred and composite cattle. Results No novel or TSE-associated PRNP-encoded amino acid polymorphisms were observed for B. indicus purebred and composite cattle, and all had the typical number of octapeptide repeats. However, differences were observed in the frequencies of the 23-bp and 12-bp insertion/deletion (indel) polymorphisms associated with two bovine PRNP transcription regulatory sites. Compared to B. taurus, B. indicus purebred and composite cattle had a significantly lower frequency of 23-bp insertion alleles and homozygous genotypes. Conversely, B. indicus purebred cattle had a significantly higher frequency of 12-bp insertion alleles and homozygous genotypes in relation to both B. taurus and composite cattle. The origin of these disparities can be attributed to a significantly different haplotype structure within each species. Conclusion The frequencies of the 23-bp and 12-bp indels were significantly different between B. indicus and B. taurus cattle. No other known or potential risk factors were detected for the B. indicus purebred and composite cattle. To date, no consensus exists regarding which bovine PRNP indel region is more influential with respect to classical BSE. Should one particular indel region and associated genotypes prove more influential with respect to the incidence of classical BSE, differences regarding overall susceptibility and resistance for B. indicus and B. taurus cattle may be elucidated. PMID:18808703

Human Factor Assessment in Support of Joint Operations

DTIC Science & Technology

2012-05-04

5d. PROJECT NUMBER LCDR Roy Hoffman, USN 5e. TASK NUMBER Paper Advisor: CDR Mark McManus, USN 5f. WORK UNIT...for example in circumstances under which “a preponderance of life stressors … or unknown personal stress” are affecting an individual’s performance...council composition, for example , best practices suggest that representatives should be present from executive, medical, chaplain, and psychological

Availability and utility of crop composition data.

PubMed

Kitta, Kazumi

2013-09-04

The safety assessment of genetically modified (GM) crops is mandatory in many countries. Although the most important factor to take into account in these safety assessments is the primary effects of artificially introduced transgene-derived traits, possible unintended effects attributed to the insertion of transgenes must be carefully examined in parallel. However, foods are complex mixtures of compounds characterized by wide variations in composition and nutritional values. Food components are significantly affected by various factors such as cultivars and the cultivation environment including storage conditions after harvest, and it can thus be very difficult to detect potential adverse effects caused by the introduction of a transgene. A comparative approach focusing on the identification of differences between GM foods and their conventional counterparts has been performed to reveal potential safety issues and is considered the most appropriate strategy for the safety assessment of GM foods. This concept is widely shared by authorities in many countries. For the efficient safety assessment of GM crops, an easily accessible and wide-ranging compilation of crop composition data is required for use by researchers and regulatory agencies. Thus, we developed an Internet-accessible food composition database comprising key nutrients, antinutrients, endogenous toxicants, and physiologically active substances of staple crops such as rice and soybeans. The International Life Sciences Institute has also been addressing the same matter and has provided the public a crop composition database of soybeans, maize, and cotton.

[Changes of diversity and composition of fungal communities in rhizosphere of Panax ginseng].

PubMed

Dong, Lin-Lin; Niu, Wei-Hao; Wang, Rui; Xu, Jiang; Zhang, Lian-Juan; Zhang, Jun; Chen, Shi-Lin

2017-02-01

Continuous cropping obstacles resulted in the yield losses of Panax ginseng, and affected the development of ginseng industry. Soil fungal communities participated in the key ecological process, and their changes of diversity and composition were related to the continuous cropping obstacles. We analyzed the changes of fungal diversity and composition in the rhizosphere of ginseng using the high-throughput sequencing method, stated the effects of ginseng cultivation on the micro-ecology, and provided effective strategies for overcoming continuous cropping obstacles. Compared to those of the forest soils, the fungal diversity of ginseng rhizosphere soils was increased, and the increasing trends were declined with an increasing years of ginseng cultivation; the relative abundance of Sordariomycetes, Alatospora, Eurotiomycetes, Leotiomycetes, Saccharomycetes, Mucorales and Pezizomycetes were increased in the rhizosphere of ginseng. Pearson's correlation index indicated that soil chemical perporties affected the relative abundance of fungal communities. pH was significantly related to the relative abundance of Dothideomycetes and Alatospora; the content of available potassium was markedly associated with the relative abundance of Dothideomycetes, Alatospora and Mucorales; the content of total nitrogen was significant correlation with the relative abundance of Sordariomycetes and Mucorales. These results indicated that fertilization was one of pivotal factors affecting the rhizosphere micro-ecology of ginseng, and optimization of fertilization system was an effective method to overcome continuous cropping obstacles. Copyright© by the Chinese Pharmaceutical Association.

Ecological and physiological controls of species composition in green macroalgal blooms.

PubMed

Nelson, Timothy A; Haberlin, Karalon; Nelson, Amorah V; Ribarich, Heather; Hotchkiss, Ruth; Van Alstyne, Kathryn L; Buckingham, Lee; Simunds, Dejah J; Fredrickson, Kerri

2008-05-01

Green macroalgal blooms have substantially altered marine community structure and function, specifically by smothering seagrasses and other primary producers that are critical to commercial fisheries and by creating anoxic conditions in enclosed embayments. Bottom-up factors are viewed as the primary drivers of these blooms, but increasing attention has been paid to biotic controls of species composition. In Washington State, USA, blooms are often dominated by Ulva spp. intertidally and Ulvaria obscura subtidally. Factors that could cause this spatial difference were examined, including competition, grazer preferences, salinity, photoacclimation, nutrient requirements, and responses to nutrient enrichment. Ulva specimens grew faster than Ulvaria in intertidal chambers but not significantly faster in subtidal chambers. Ulva was better able to acclimate to a high-light environment and was more tolerant of low salinity than Ulvaria. Ulvaria had higher tissue N content, chlorophyll, chlorophyll b: chlorophyll a, and protein content than Ulva. These differences suggest that nitrogen availability could affect species composition. A suite of five grazers preferred Ulva to Ulvaria in choice experiments. Thus, bottom-up factors allow Ulva to dominate the intertidal zone while resistance to grazers appears to allow Ulvaria to dominate the subtidal zone. While ulvoid algae are in the same functional-form group, they are not functionally redundant.

Lipodystrophy in HIV patients: its challenges and management approaches.

PubMed

Singhania, Rohit; Kotler, Donald P

2011-01-01

HIV-associated lipodystrophy is a term used to describe a constellation of body composition (lipoatrophy and lipohypertrophy) and metabolic (dyslipidemia and insulin resistance) alterations that accompany highly active antiretroviral therapy. These changes, which resemble metabolic syndrome, have been associated with a variety of adverse outcomes including accelerated cardiovascular disease. The body composition and metabolic changes appear to cluster in HIV infection, although they are distinct alterations and do not necessarily coexist. Epidemiological studies have demonstrated multiple pathogenic influences associated with host, disease, and treatment-related factors. The adverse treatment effects were more prominent in early regimens; continued drug development has led to the application of metabolically safer regimens with equal or greater potency than the regimens being replaced. Disease-related factors include HIV infection as well as inflammation, immune activation, and immune depletion. The body composition changes promote anxiety and depression in patients and may affect treatment adherence. Treatment of dyslipidemia and alterations in glucose metabolism is the same as in non-HIV-infected individuals. Lipoatrophy is managed by strategic choice of antivirals or by antiviral switching, and in some cases by plastic/reconstructive surgery. Lipohypertrophy has been managed mainly by lifestyle modification, ie, a hypocaloric diet and increased exercise. A growth hormone releasing factor, which reduces central fat, has recently become available for clinical use.

Lipodystrophy in HIV patients: its challenges and management approaches

PubMed Central

Singhania, Rohit; Kotler, Donald P

2011-01-01

HIV-associated lipodystrophy is a term used to describe a constellation of body composition (lipoatrophy and lipohypertrophy) and metabolic (dyslipidemia and insulin resistance) alterations that accompany highly active antiretroviral therapy. These changes, which resemble metabolic syndrome, have been associated with a variety of adverse outcomes including accelerated cardiovascular disease. The body composition and metabolic changes appear to cluster in HIV infection, although they are distinct alterations and do not necessarily coexist. Epidemiological studies have demonstrated multiple pathogenic influences associated with host, disease, and treatment-related factors. The adverse treatment effects were more prominent in early regimens; continued drug development has led to the application of metabolically safer regimens with equal or greater potency than the regimens being replaced. Disease-related factors include HIV infection as well as inflammation, immune activation, and immune depletion. The body composition changes promote anxiety and depression in patients and may affect treatment adherence. Treatment of dyslipidemia and alterations in glucose metabolism is the same as in non-HIV-infected individuals. Lipoatrophy is managed by strategic choice of antivirals or by antiviral switching, and in some cases by plastic/reconstructive surgery. Lipohypertrophy has been managed mainly by lifestyle modification, ie, a hypocaloric diet and increased exercise. A growth hormone releasing factor, which reduces central fat, has recently become available for clinical use. PMID:22267946

The intricate association between gut microbiota and development of type 1, type 2 and type 3 diabetes.

PubMed

Bekkering, Pjotr; Jafri, Ismael; van Overveld, Frans J; Rijkers, Ger T

2013-11-01

It has been proposed that changes in the composition of gut microbiota contribute to the development of diabetes Types 1, 2 and 3 (the latter known as Alzheimer's disease). The onset of these diseases is affected by complex interactions of genetic and several environmental factors. Alterations in gut microbiota in combination with specific diets can result in increased intestinal permeability leading via a continuous state of low-grade inflammation to the development of insulin resistance. Since a change in composition of gut microbiota is also suggested to be the underlying factor for the development of obesity, it is obvious to link gut microbiota with the pathogenesis of diabetes. In addition, insulin resistance in the brain has been recently associated with Alzheimer's disease. These new paradigms in combination with data from studies with prebiotics and probiotics may lead to a novel way to control and even prevent diabetes in general.

Manipulating cinnamyl alcohol dehydrogenase (CAD) expression in flax affects fibre composition and properties

PubMed Central

2014-01-01

Background In recent decades cultivation of flax and its application have dramatically decreased. One of the reasons for this is unpredictable quality and properties of flax fibre, because they depend on environmental factors, retting duration and growing conditions. These factors have contribution to the fibre composition, which consists of cellulose, hemicelluloses, lignin and pectin. By far, it is largely established that in flax, lignin reduces an accessibility of enzymes either to pectin, hemicelluloses or cellulose (during retting or in biofuel synthesis and paper production). Therefore, in this study we evaluated composition and properties of flax fibre from plants with silenced CAD (cinnamyl alcohol dehydrogenase) gene, which is key in the lignin biosynthesis. There is evidence that CAD is a useful tool to improve lignin digestibility and/or to lower the lignin levels in plants. Results Two studied lines responded differentially to the introduced modification due to the efficiency of the CAD silencing. Phylogenetic analysis revealed that flax CAD belongs to the “bona-fide” CAD family. CAD down-regulation had an effect in the reduced lignin amount in the flax fibre cell wall and as FT-IR results suggests, disturbed lignin composition and structure. Moreover introduced modification activated a compensatory mechanism which was manifested in the accumulation of cellulose and/or pectin. These changes had putative correlation with observed improved fiber’s tensile strength. Moreover, CAD down-regulation did not disturb at all or has only slight effect on flax plants’ development in vivo, however, the resistance against flax major pathogen Fusarium oxysporum decreased slightly. The modification positively affected fibre possessing; it resulted in more uniform retting. Conclusion The major finding of our paper is that the modification targeted directly to block lignin synthesis caused not only reduced lignin level in fibre, but also affected amount and organization of cellulose and pectin. However, to conclude that all observed changes are trustworthy and correlated exclusively to CAD repression, further analysis of the modified plants genome is necessary. Secondly, this is one of the first studies on the crop from the low-lignin plants from the field trail which demonstrates that such plants could be successfully cultivated in a field. PMID:24552628

Nitrogen Forms Influence Microcystin Concentration and Composition via Changes in Cyanobacterial Community Structure

PubMed Central

Monchamp, Marie-Eve; Pick, Frances R.; Beisner, Beatrix E.; Maranger, Roxane

2014-01-01

The eutrophication of freshwaters is a global health concern as lakes with excess nutrients are often subject to toxic cyanobacterial blooms. Although phosphorus is considered the main element regulating cyanobacterial biomass, nitrogen (N) concentration and more specifically the availability of different N forms may influence the overall toxicity of blooms. In this study of three eutrophic lakes prone to cyanobacterial blooms, we examined the effects of nitrogen species and concentrations and other environmental factors in influencing cyanobacterial community structure, microcystin (MC) concentrations and MC congener composition. The identification of specific MC congeners was of particular interest as they vary widely in toxicity. Different nitrogen forms appeared to influence cyanobacterial community structure leading to corresponding effects on MC concentrations and composition. Total MC concentrations across the lakes were largely explained by a combination of abiotic factors: dissolved organic nitrogen, water temperature and ammonium, but Microcystis spp. biomass was overall the best predictor of MC concentrations. Environmental factors did not appear to affect MC congener composition directly but there were significant associations between specific MC congeners and particular species. Based on redundancy analyses (RDA), the relative biomass of Microcystis aeruginosa was associated with MC-RR, M. wesenbergii with MC-LA and Aphanizomenon flos-aquae with MC-YR. The latter two species are not generally considered capable of MC production. Total nitrogen, water temperature, ammonium and dissolved organic nitrogen influenced the cyanobacterial community structure, which in turn resulted in differences in the dominant MC congener and the overall toxicity. PMID:24427318

Interactions between above- and belowground organisms modified in climate change experiments

NASA Astrophysics Data System (ADS)

Stevnbak, Karen; Scherber, Christoph; Gladbach, David J.; Beier, Claus; Mikkelsen, Teis N.; Christensen, Søren

2012-11-01

Climate change has been shown to affect ecosystem process rates and community composition, with direct and indirect effects on belowground food webs. In particular, altered rates of herbivory under future climate can be expected to influence above-belowground interactions. Here, we use a multifactor, field-scale climate change experiment and independently manipulate atmospheric CO2 concentration, air and soil temperature and drought in all combinations since 2005. We show that changes in these factors modify the interaction between above- and belowground organisms. We use an insect herbivore to experimentally increase aboveground herbivory in grass phytometers exposed to all eight combinations of climate change factors for three years. Aboveground herbivory increased the abundance of belowground protozoans, microbial growth and microbial nitrogen availability. Increased CO2 modified these links through a reduction in herbivory and cascading effects through the soil food web. Interactions between CO2, drought and warming can affect belowground protozoan abundance. Our findings imply that climate change affects aboveground-belowground interactions through changes in nutrient availability.

Relationship between bacterial diversity and environmental parameters during composting of different raw materials.

PubMed

Wang, Xueqin; Cui, Hongyang; Shi, Jianhong; Zhao, Xinyu; Zhao, Yue; Wei, Zimin

2015-12-01

The aim of this study was to compare the bacterial structure of seven different composts. The primary environmental factors affecting bacterial species were identified, and a strategy to enhance the abundance of uncultured bacteria through controlling relevant environmental parameters was proposed. The results showed that the physical-chemical parameters of each different pile changed in its own manner during composting, which affected the structure and succession of bacteria in different ways. DGGE profiles showed that there were 10 prominent species during composting. Among them, four species existed in all compost types, two species existed in several piles and four species were detected in a single material. Redundancy analysis results showed that bacterial species compositions were significantly influenced by C/N and moisture (p<0.05). The optimal range of C/N was 14-27. Based on these results, the primary environmental factors affecting a certain species were further identified as a potential control of bacterial diversity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Work-related to musculoskeletal disorder amongst Malaysian construction trade workers: Bricklayers

NASA Astrophysics Data System (ADS)

Lop, Nor Suzila; Kamar, Izatul Farrita Mohd; Aziz, Mohd Nasiruddin Abdul; Abdullah, Lizawati; Akhir, Norizan Mt

2017-10-01

Construction sector is one of the highest risk industries contributing to the development of work-related musculoskeletal disorders. In general construction activities involve the composition of various construction trades, such as painting, plastering, concreting, paving and bricklaying. Different construction trades workers are exposed to risk factors depending their job and task. There are risk factors associated with the construction trade workers activities such as concrete work, brickwork, piling work excavation works and etc. Thus, the aim of this research is to document the critical activities that affect the musculoskeletal disorders amongst Malaysian construction trade workers, in particular to the bricklayers. The objective of this research is to identify the critical activities that affect to the musculoskeletal disorder among the bricklayers. The data for this research was collected via observation to the construction workers for the specific trades which are bricklayers in Perak. Finding of this research is by identifying the critical activities involved that affect the musculoskeletal disorder suffering among bricklayers.

Benthic invertebrate communities and their responses to selected environmental factors in the Kanawha River basin, West Virginia, Virginia, and North Carolina

USGS Publications Warehouse

Chambers, Douglas B.; Messinger, Terence

2001-01-01

The effects of selected environmental factors on the composition and structure of benthic invertebrate communities in the Kanawha River Basin of West Virginia, Virginia and North Carolina were investigated in 1997 and 1998. Environmental factors investigated include physiography, land-use pattern, streamwater chemistry, streambed- sediment chemistry, and habitat characteristics. Land-use patterns investigated include coal mining, agriculture, and low intensity rural-residential patterns, at four main stem and seven tributary sites throughout the basin. Of the 37 sites sampled, basin size and physiography most strongly affected benthic invertebrate-community structure. Land-use practices also affected invertebrate community structure in these basins. The basins that differed most from the minimally affected reference condition were those basins in which coal mining was the dominant nonforest land use, as determined by comparing invertebrate- community metric values among sites. Basins in which agriculture was important were more similar to the reference condition. The effect of coal mining upon benthic invertebrate communities was further studied at 29 sites and the relations among invertebrate communities and the selected environmental factors of land use, streamwater chemistry, streambed- sediment chemistry, and habitat characteristics analyzed. Division of coal-mining synoptic-survey sites based on invertebrate-community composition resulted in two groups?one with more than an average production of 9,000 tons of coal per square mile per year since 1980, and one with lesser or no recent coal production. The group with significant recent coal production showed higher levels of community impairment than the group with little or no recent coal production. Median particle size of streambed sediment, and specific conductance and sulfate concentration of streamwater were most strongly correlated with effects on invertebrate communities. These characteristics were related to mining intensity, as measured by thousands of tons of coal produced per square mile of drainage area.

Precambrian evolution of the climate system.

PubMed

Walker, J C

1990-01-01

Climate is an important environmental parameter of the early Earth, likely to have affected the origin and evolution of life, the composition and mineralogy of sedimentary rocks, and stable isotope ratios in sedimentary minerals. There is little observational evidence constraining Precambrian climates. Most of our knowledge is at present theoretical. Factors that must have affected the climate include reduced solar luminosity, enhanced rotation rate of the Earth, an area of land that probably increased with time, and biological evolution, particularly as it affected the composition of the atmosphere and the greenhouse effect. Cloud cover is a major uncertainty about the early Earth. Carbon dioxide and its greenhouse effect are the factors that have been most extensively studied. This paper presents a new examination of the biogeochemical cycles of carbon as they may have changed between an Archean Earth deficient in land, sedimentary rocks, and biological activity, and a Proterozoic Earth much like the modern Earth, but lacking terrestrial life and carbonate-secreting plankton. Results of a numerical simulation of this transition show how increasing biological activity could have drawn down atmospheric carbon dioxide by extracting sedimentary organic carbon from the system. Increasing area of continents could further have drawn down carbon dioxide by encouraging the accumulation of carbonate sediments. An attempt to develop a numerical simulation of the carbon cycles of the Precambrian raises questions about sources and sinks of marine carbon and alkalinity on a world without continents. More information is needed about sea-floor weathering processes.

Climate Controls AM Fungal Distributions from Global to Local Scales

NASA Astrophysics Data System (ADS)

Kivlin, S. N.; Hawkes, C.; Muscarella, R.; Treseder, K. K.; Kazenel, M.; Lynn, J.; Rudgers, J.

2016-12-01

Arbuscular mycorrhizal (AM) fungi have key functions in terrestrial biogeochemical processes; thus, determining the relative importance of climate, edaphic factors, and plant community composition on their geographic distributions can improve predictions of their sensitivity to global change. Local adaptation by AM fungi to plant hosts, soil nutrients, and climate suggests that all of these factors may control fungal geographic distributions, but their relative importance is unknown. We created species distribution models for 142 AM fungal taxa at the global scale with data from GenBank. We compared climate variables (BioClim and soil moisture), edaphic variables (phosphorus, carbon, pH, and clay content), and plant variables using model selection on models with (1) all variables, (2) climatic variables only (including soil moisture) and (3) resource-related variables only (all other soil parameters and NPP) using the MaxEnt algorithm evaluated with ENMEval. We also evaluated whether drivers of AM fungal distributions were phylogenetically conserved. To test whether global correlates of AM fungal distributions were reflected at local scales, we then surveyed AM fungi in nine plant hosts along three elevation gradients in the Upper Gunnison Basin, Colorado, USA. At the global scale, the distributions of 55% of AM fungal taxa were affected by both climate and soil resources, whereas 16% were only affected by climate and 29% were only affected by soil resources. Even for AM fungi that were affected by both climate and resources, the effects of climatic variables nearly always outweighed those of resources. Soil moisture and isothermality were the main climatic and NPP and soil carbon the main resource related factors influencing AM fungal distributions. Distributions of closely related AM fungal taxa were similarly affected by climate, but not by resources. Local scale surveys of AM fungi across elevations confirmed that climate was a key driver of AM fungal composition and root colonization, with weaker influences of plant identity and soil nutrients. These two studies across scales suggest prevailing effects of climate on AM fungal distributions. Thus, incorporating climate when forecasting future ranges of AM fungi will enhance predictions of AM fungal abundance and associated ecosystem functions.

Multi response optimization of sheet forming of Kenaf-Polypropylene composites using grey based fuzzy algorithm

NASA Astrophysics Data System (ADS)

Oktariani, Erfina; Istikowati, Rita; Tomo, Hendro Sat Setijo; Rizal, Rafliansyah; Pratama, Yosea

2018-02-01

Composites from natural fiber reinforcement are developed as the alternative sheet materials of plastic composite for small-size bodywork parts in automotive industries. Kenaf fiber is selected as the reinforcement of plastic composite. Press forming of Kenaf-Polypropylene is experimentally produced in this study. The aim of this study is to obtain the optimal factor of the process of sheet forming of Kenaf-Polypropylene. The Kenaf delignified is cut into 5 cm lengths and distributed on the surface of Polypropylene sheet for 3 and 5 ply layers. The layers of Kenaf-Polypropylene then pressed by hot press at 190 and 210°C, 40 and 50 bar, for 3 and 5 minutes. However, there are limitations in handling multi responses in design of experiments. The application of the fuzzy logic theory to the grey relational analysis may further develop its performance in solving multi-response problems for process parameter optimization. The layer of Kenaf and Polypropylene, temperature, the duration of hot press and pressure are factors that affect the process. The result of experimental investigation and as well as analysis, shows that the best combination values were 3 ply layer, 210°C, 5 minutes of hot press and 50 bar.

Urban-development-induced Changes in the Diversity and Composition of the Soil Bacterial Community in Beijing.

PubMed

Yan, Bing; Li, Junsheng; Xiao, Nengwen; Qi, Yue; Fu, Gang; Liu, Gaohui; Qiao, Mengping

2016-12-09

Numerous studies have implicated urbanization as a major cause of loss of biodiversity. Most of them have focused on plants and animals, even though soil microorganisms make up a large proportion of that biodiversity. However, it is unclear how the soil bacterial community is affected by urban development. Here, paired-end Illumina sequencing of the 16 S rRNA gene at V4 region was performed to study the soil microbial community across Beijing's built-up area. Proteobacteria, Acidobacteria, Bacteroidetes, Actinobacteria, Gemmatimonadetes, Verrucomicrobia, Planctomycetes, and Chloroflexi were the dominant phyla in all samples, but the relative abundance of these phyla differed significantly across these concentric zones. The diversity and composition of the soil bacterial community were found to be closely correlated with soil pH. Variance partitioning analysis suggested that urban ring roads contributed 5.95% of the bacterial community variation, and soil environmental factors explained 17.65% of the variation. The results of the current work indicate that urban development can alter the composition and diversity of the soil microbial community, and showed pH to be a key factor in the shaping of the composition of the soil bacterial community. Urban development did have a strong impact on the bacterial community of urban soil in Beijing.

Urban-development-induced Changes in the Diversity and Composition of the Soil Bacterial Community in Beijing

NASA Astrophysics Data System (ADS)

Yan, Bing; Li, Junsheng; Xiao, Nengwen; Qi, Yue; Fu, Gang; Liu, Gaohui; Qiao, Mengping

2016-12-01

Numerous studies have implicated urbanization as a major cause of loss of biodiversity. Most of them have focused on plants and animals, even though soil microorganisms make up a large proportion of that biodiversity. However, it is unclear how the soil bacterial community is affected by urban development. Here, paired-end Illumina sequencing of the 16 S rRNA gene at V4 region was performed to study the soil microbial community across Beijing’s built-up area. Proteobacteria, Acidobacteria, Bacteroidetes, Actinobacteria, Gemmatimonadetes, Verrucomicrobia, Planctomycetes, and Chloroflexi were the dominant phyla in all samples, but the relative abundance of these phyla differed significantly across these concentric zones. The diversity and composition of the soil bacterial community were found to be closely correlated with soil pH. Variance partitioning analysis suggested that urban ring roads contributed 5.95% of the bacterial community variation, and soil environmental factors explained 17.65% of the variation. The results of the current work indicate that urban development can alter the composition and diversity of the soil microbial community, and showed pH to be a key factor in the shaping of the composition of the soil bacterial community. Urban development did have a strong impact on the bacterial community of urban soil in Beijing.

Electrochemical lithiation performance and characterization of silicon-graphite composites with lithium, sodium, potassium, and ammonium polyacrylate binders.

PubMed

Han, Zhen-Ji; Yamagiwa, Kiyofumi; Yabuuchi, Naoaki; Son, Jin-Young; Cui, Yi-Tao; Oji, Hiroshi; Kogure, Akinori; Harada, Takahiro; Ishikawa, Sumihisa; Aoki, Yasuhito; Komaba, Shinichi

2015-02-07

Poly(acrylic acid) (PAH), which is a water soluble polycarboxylic acid, is neutralized by adding different amounts of LiOH, NaOH, KOH, and ammonia (NH4OH) aqueous solutions to fix neutralization degrees. The differently neutralized polyacid, alkali and ammonium polyacrylates are examined as polymeric binders for the preparation of Si-graphite composite electrodes as negative electrodes for Li-ion batteries. The electrode performance of the Si-graphite composite depends on the alkali chemicals and neutralization degree. It is found that 80% NaOH-neutralized polyacrylate binder (a pH value of the resultant aqueous solution is ca. 6.7) is the most efficient binder to enhance the electrochemical lithiation and de-lithiation performance of the Si-graphite composite electrode compared to that of conventional PVdF and the other binders used in this study. The optimum polyacrylate binder highly improves the dispersion of active material in the composite electrode. The binder also provides the strong adhesion, suitable porosity, and hardness for the composite electrode with 10% (m/m) binder content, resulting in better electrochemical reversibility. From these results, the factors of alkali-neutralized polyacrylate binders affecting the electrode performance of Si-graphite composite electrodes are discussed.

The effect of rotatory inertia on the natural frequencies of composite beams

NASA Astrophysics Data System (ADS)

Auclair, Samuel C.; Sorelli, Luca; Salenikovich, Alexander; Fafard, Mario

2016-03-01

This paper focuses on the dynamic behaviour of two-layer composite beams, which is an important aspect of performance of structures, such as a concrete slab on a girder in residential floors or bridges. After briefly reviewing the composite beam theory based on Euler-Bernoulli hypothesis, the dynamic formulation is extended by including the effect of the relative longitudinal motion of the layers in the rotatory inertia, which can be particularly important for timber-concrete composite beams. The governing equation and the finite element model are derived in detail and validated by comparing the natural frequency predictions against other methods. A parametric analysis shows the key factors, which affect the rotatory inertia and its influence on the frequency of a single-span composite beam with different boundary conditions. The effect of the rotatory inertia on the first natural frequency of the composite beam appears below 5 percent; however, the effect on the higher natural frequencies becomes more important and not negligible in a full dynamics analysis. Finally, a simplified equation is proposed to account for the effect of the rotatory inertia on the calculation of the frequency of a composite beam for design purpose.

Plasma membrane lipid–protein interactions affect signaling processes in sterol-biosynthesis mutants in Arabidopsis thaliana

PubMed Central

Zauber, Henrik; Burgos, Asdrubal; Garapati, Prashanth; Schulze, Waltraud X.

2014-01-01

The plasma membrane is an important organelle providing structure, signaling and transport as major biological functions. Being composed of lipids and proteins with different physicochemical properties, the biological functions of membranes depend on specific protein–protein and protein–lipid interactions. Interactions of proteins with their specific sterol and lipid environment were shown to be important factors for protein recruitment into sub-compartmental structures of the plasma membrane. System-wide implications of altered endogenous sterol levels for membrane functions in living cells were not studied in higher plant cells. In particular, little is known how alterations in membrane sterol composition affect protein and lipid organization and interaction within membranes. Here, we conducted a comparative analysis of the plasma membrane protein and lipid composition in Arabidopsis sterol-biosynthesis mutants smt1 and ugt80A2;B1. smt1 shows general alterations in sterol composition while ugt80A2;B1 is significantly impaired in sterol glycosylation. By systematically analyzing different cellular fractions and combining proteomic with lipidomic data we were able to reveal contrasting alterations in lipid–protein interactions in both mutants, with resulting differential changes in plasma membrane signaling status. PMID:24672530

Competing factors of compost concentration and proximity to root affect the distribution of streptomycetes.

PubMed

Inbar, Ehud; Green, Stefan J; Hadar, Yitzhak; Minz, Dror

2005-07-01

Streptomycetes are important members of soil microbial communities and are particularly active in the degradation of recalcitrant macromolecules and have been implicated in biological control of plant disease. Using a streptomycetes-specific polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (PCR-DGGE) methodology coupled with band excision and sequence analysis, we examined the effect of grape marc compost amendment to soil on cucumber plant-associated streptomycetes community composition. We observed that both compost amendment and proximity to the root surface influenced the streptomycetes community composition. A strong root selection for a soil-derived Streptomycete, most closely related to Streptomyces thermotolerans, S. iakyrus, and S. thermocarboxydus, was independent of compost amendment rate. However, while the impact of compost amendment was mitigated with increasing proximity to the root, high levels of compost amendment resulted in the detection of compost-derived species on the root surface. Conversely, in rhizosphere and non-rhizosphere soils, the community composition of streptomycetes was affected strongly even by modest compost amendment. The application of a streptomycetes-specific PCR primer set combined with DGGE analysis provided a rapid means of examining the distribution and ecology of streptomycetes in soils and plant-associated environments.

Effects of gas composition in headspace and bicarbonate concentrations in media on gas and methane production, degradability, and rumen fermentation using in vitro gas production techniques.

PubMed

Patra, Amlan Kumar; Yu, Zhongtang

2013-07-01

Headspace gas composition and bicarbonate concentrations in media can affect methane production and other characteristics of rumen fermentation in in vitro gas production systems, but these 2 important factors have not been evaluated systematically. In this study, these 2 factors were investigated with respect to gas and methane production, in vitro digestibility of feed substrate, and volatile fatty acid (VFA) profile using in vitro gas production techniques. Three headspace gas compositions (N2+ CO2+ H2 in the ratio of 90:5:5, CO2, and N2) with 2 substrate types (alfalfa hay only, and alfalfa hay and a concentrate mixture in a 50:50 ratio) in a 3×2 factorial design (experiment 1) and 3 headspace compositions (N2, N2 + CO2 in a 50:50 ratio, and CO2) with 3 bicarbonate concentrations (80, 100, and 120 mM) in a 3×3 factorial design (experiment 2) were evaluated. In experiment 1, total gas production (TGP) and net gas production (NGP) was the lowest for CO2, followed by N2, and then the gas mixture. Methane concentration in headspace gas after fermentation was greater for CO2 than for N2 and the gas mixture, whereas total methane production (TMP) and net methane production (NMP) were the greatest for CO2, followed by the gas mixture, and then N2. Headspace composition did not affect in vitro digestibility or the VFA profile, except molar percentages of propionate, which were greater for CO2 and N2 than for the gas mixture. Methane concentration in headspace gas, TGP, and NGP were affected by the interaction of headspace gas composition and substrate type. In experiment 2, increasing concentrations of CO2 in the headspace decreased TGP and NGP quadratically, but increased the concentrations of methane, NMP, and in vitro fiber digestibility linearly, and TMP quadratically. Fiber digestibility, TGP, and NGP increased linearly with increasing bicarbonate concentrations in the medium. Concentrations of methane and NMP were unaffected by bicarbonate concentration, but TMP tended to increase due to increasing bicarbonate concentration. Although total VFA concentration and molar percentage of butyrate were unchanged, the molar percentage of acetate, and acetate-to-propionate ratio decreased, whereas the molar percentage of propionate increased quadratically with increasing bicarbonate concentration. This study demonstrated for the first time that headspace composition, especially CO2 content, and bicarbonate concentration in media could significantly influence gas and methane production, and rumen fermentation in gas production techniques. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Drivers of Macrofungi Community Structure Differ between Soil and Rotten-Wood Substrates in a Temperate Mountain Forest in China

PubMed Central

Chen, Yun; Svenning, Jens-Christian; Wang, Xueying; Cao, Ruofan; Yuan, Zhiliang; Ye, Yongzhong

2018-01-01

The effects of environmental and dispersal processes on macrofungi community assembly remain unclear. Further, it is not well understood if community assembly differs for different functional guilds of macrofungi, e.g., soil and rotten-wood macrofungi. In this study, using 2433 macrofungi sporocarps belonging to 217 species located within a forest dynamics plot in temperate mountain forest (China), we examined the explanatory power of topography, spatial eigenvectors (representing unknown spatial processes, e.g., dispersal), plant community, and light availability for local spatial variation in the macrofungi community through variance partitioning and partial least squares path modeling. We found spatial eigenvectors and light as the most important factors for explaining species richness and composition of macrofungi. Light was negatively correlated with species richness of macrofungi. Furthermore, species richness and composition of soil macrofungi were best explained by light, and species richness and composition of rotten-wood macrofungi were best explained by spatial eigenvectors. Woody plant community structure was not an important factor for species richness and composition of macrofungi. Our findings suggest that spatial processes, perhaps dispersal limitation, and light availability were the most important factors affecting macrofungi community in temperate deciduous broad-leaved forest. Major differences in influencing factors between soil and rotten-wood macrofungi were observed, with light as the major driver for soil macrofungi and unknown spatial processes as the major driver for rotten-wood macrofungi. These findings shed new light to the processes shaping community assembly in macrofungi in temperate deciduous broad-leaved forest and point to the potential importance of both intrinsic dynamics, such as dispersal, and external forcing, such as forest dynamics, via its effect on light availability. PMID:29410660

Temporal Dynamics of the Human Vaginal Microbiota

PubMed Central

Gajer, Pawel; Brotman, Rebecca M.; Bai, Guoyun; Sakamoto, Joyce; Schütte, Ursel M.E.; Zhong, Xue; Koenig, Sara S.K.; Fu, Li; Ma, Zhanshan; Zhou, Xia; Abdo, Zaid; Forney, Larry J.; Ravel, Jacques

2012-01-01

Elucidating the factors that impinge on the stability of bacterial communities in the vagina may help in predicting the risk of diseases that affect women’s health. Here, we describe the temporal dynamics of the composition of vaginal bacterial communities in 32 reproductive age women over a 16-week period. The analysis revealed the dynamics of five major classes of bacterial communities and showed that some communities change markedly over short time periods, whereas others are relatively stable. Modeling community stability using new quantitative measures indicates that deviation from stability correlates with time in the menstrual cycle, bacterial community composition and sexual activity. The women studied are healthy, thus it appears that neither variation in community composition per se, nor higher levels of observed diversity (co-dominance) are necessarily indicative of dysbiosis, in which there is microbial imbalance accompanied by symptoms. PMID:22553250

Identification of significant medium components that affect docosahexaenoic acid production by Schizochytrium sp. SW1

NASA Astrophysics Data System (ADS)

Manikan, Vidyah; Hamid, Aidil A.

2013-11-01

Central composite design (CCD) was employed to investigate the significance of glucose, yeast extract, MSG and sea salt in affecting the amount of docosahexaenoic acid (DHA) accumulated by a locally isolated strain of Schizochytrium. Design Expert software was used to construct a set of experiments where each medium component mentioned above was varied over three levels. Cultivation was carried out in 250mL flasks containing 50mL of medium, incubated at 30°C with 200 rpm agitation for 96 hours. ANOVA was conducted to identify the influential factors and the level of their significance where factors that scored a probability value of less than 0.05 were considered significant. The level of influence for each independent variable was also interpreted using perturbation whereas pattern of interaction between the factors were interpreted using interaction plots. This experiment revealed that yeast extract and monosodium glutamate have significant influence on DHA accumulation process by Schizochytrium sp. SW1.

Impact of different ratios of feedstock to liquid anaerobic digestion effluent on the performance and microbiome of solid-state anaerobic digesters digesting corn stover.

PubMed

Li, Yueh-Fen; Shi, Jian; Nelson, Michael C; Chen, Po-Hsu; Graf, Joerg; Li, Yebo; Yu, Zhongtang

2016-01-01

The objective of this study was to understand how the non-microbial factors of L-AD effluent affected the microbiome composition and successions in the SS-AD digesters using both Illumina sequencing and qPCR quantification of major genera of methanogens. The SS-AD digesters started with a feedstock/total effluent (F/Et) ratio 2.2 (half of the effluent was autoclaved) performed stably, while the SS-AD digesters started with a 4.4 F/Et ratio (no autoclaved effluent) suffered from digester acidification, accumulation of volatile fatty acids, and ceased biogas production two weeks after startup. Some bacteria and methanogens were affected by non-microbial factors of the L-AD fluent. Alkalinity, the main difference between the two F/Et ratios, may be the crucial factor when SS-AD digesters were started using L-AD effluent. Copyright © 2015 Elsevier Ltd. All rights reserved.

Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats.

PubMed

Rocha, C F D; Hatano, F H; Vrcibradic, D; Van Sluys, M

2008-02-01

We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation) along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí), Espírito Santo (Praia das Neves and Setiba) and Bahia (Prado and Trancoso). We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species), followed by Grussaí and Trancoso (eight species in each). The commonest species in the restingas was Scinax alter (found in eight restingas), followed by Aparasphenodon brunoi (seven areas). Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances) seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13 degrees; p = 0.007). Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical factors. This nestedness pattern, in part, probably results from the intensive fragmentation of restinga habitats. Possibly, many frog species may have been lost in some studied areas as a result of the extensive habitat degradation to which restinga habitats are presently exposed.

Does Being Assigned to a Low School Track Negatively Affect Psychological Adjustment? A Longitudinal Study in the First Year of Secondary School

ERIC Educational Resources Information Center

Müller, Christoph Michael; Hofmann, Verena

2016-01-01

Previous research suggests that the 1st year in secondary school for some students goes hand in hand with an increase in adjustment difficulties. One factor that might influence this process on an individual, compositional, and institutional level is the academic track a student attends. It was hypothesized that being assigned to a low-qualifying…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Padaki, S.; Drzal, L.T.

The consolidation process in composites made out of powder impregnated tapes differs from that of other material forms because of the distribution of fiber and matrix in the unconsolidated state. A number of factors (e.g. time, pressure, particle size, volume fraction and viscosity) affect the efficiency of the consolidation of these tapes. This paper describes the development of a mathematical process model that describes the best set of parameters required for the consolidation of a given prepreg tape.

Spatially dependent biotic and abiotic factors drive survivorship and physical structure of green roof vegetation.

PubMed

Aloisio, Jason M; Palmer, Matthew I; Giampieri, Mario A; Tuininga, Amy R; Lewis, James D

2017-01-01

Plant survivorship depends on biotic and abiotic factors that vary at local and regional scales. This survivorship, in turn, has cascading effects on community composition and the physical structure of vegetation. Survivorship of native plant species is variable among populations planted in environmentally stressful habitats like urban roofs, but the degree to which factors at different spatial scales affect survivorship in urban systems is not well understood. We evaluated the effects of biotic and abiotic factors on survivorship, composition, and physical structure of two native perennial species assemblages, one characterized by a mixture of C 4 grasses and forbs (Hempstead Plains, HP) and one characterized by a mixture of C 3 grasses and forbs (Rocky Summit, RS), that were initially sown at equal ratios of growth forms (5:1:4; grass, N-fixing forb and non-N-fixing forb) in replicate 2-m 2 plots planted on 10 roofs in New York City (New York, USA). Of 24 000 installed plants, 40% survived 23 months after planting. Within-roof factors explained 71% of variation in survivorship, with biotic (species identity and assemblage) factors accounting for 54% of the overall variation, and abiotic (growing medium depth and plot location) factors explaining 17% of the variation. Among-roof factors explained 29% of variation in survivorship and increased solar radiation correlated with decreased survivorship. While growing medium properties (pH, nutrients, metals) differed among roofs there was no correlation with survivorship. Percent cover and sward height increased with increasing survivorship. At low survivorship, cover of the HP assemblage was greater compared to the RS assemblage. Sward height of the HP assemblage was about two times greater compared to the RS assemblage. These results highlight the effects of local biotic and regional abiotic drivers on community composition and physical structure of green roof vegetation. As a result, initial green roof plant composition and roof microclimate may have long-term effects on community dynamics, ecosystem function, and urban biodiversity. © 2016 by the Ecological Society of America.

Loss of lean body mass affects low bone mineral density in patients with rheumatoid arthritis - results from the TOMORROW study.

PubMed

Okano, Tadashi; Inui, Kentaro; Tada, Masahiro; Sugioka, Yuko; Mamoto, Kenji; Wakitani, Shigeyuki; Koike, Tatsuya; Nakamura, Hiroaki

2017-11-01

Osteoporosis is one of the complications for patients with rheumatoid arthritis (RA). Rheumatoid cachexia, the loss of lean body mass, is another. However, the relationship between decreased lean body mass and reduced bone mineral density (BMD) in patients with RA has not been well studied. This study included 413 participants, comprising 208 patients with RA and 205 age- and sex-matched healthy volunteers. Clinical data, BMD, bone metabolic markers (BMM) and body composition, such as lean body mass and percent fat, were collected. Risk factors for osteoporosis in patients with RA including the relationship BMD and body composition were analyzed. Patients with RA showed low BMD and high BMM compared with controls. Moreover, lean body mass was lower and percent fat was higher in patients with RA. Lean body mass correlated positively and percent fat negatively with BMD. Lean body mass was a positive and disease duration was a negative independent factor for BMD in multivariate statistical analysis. BMD and lean body mass were significantly lower in patients with RA compared to healthy controls. Lean body mass correlated positively with BMD and decreased lean body mass and disease duration affected low BMD in patients with RA. [UMIN Clinical Trials Registry, http://www.umin.ac.jp/ctr/ , UMIN000003876].

Environmental Barrier Coatings for Ceramics and Ceramic Composites

NASA Technical Reports Server (NTRS)

Lee, Kang N.; Fox, Dennis; Eldridge, Jeffrey; Robinson, R. Craig; Bansal, Narottam

2004-01-01

One key factor that limits the performance of current gas turbine engines is the temperature capability of hot section structural components. Silicon-based ceramics, such as SiC/SiC composites and monolithic Si3N4, are leading candidates to replace superalloy hot section components in the next generation gas turbine engines due to their excellent high temperature properties. A major stumbling block to realizing Si-based ceramic hot section components is the recession of Si-based ceramics in combustion environments due to the volatilization of silica scale by water vapor. An external environmental barrier coating (EBC) is the most promising approach to preventing the recession. Current EBCs are based on silicon, mullite (3A12O3-2SiO2) and BSAS (barium strontium aluminum silicate with celsian structure). Volatility of BSAS, BSAS-silica chemical reaction, and low melting point of silicon limit the durability and temperature capability of current EBCs. Research is underway to develop EBCs with longer life and enhanced temperature capability. Understanding key issues affecting the performance of current EBCs is necessary for successful development of advanced EBCs. These issues include stress, chemical compatibility, adherence, and water vapor stability. Factors that affect stress are thermal expansion mismatch, phase stability, chemical stability, elastic modulus, etc. The current understanding on these issues will be discussed.

Factors affecting ethylene and carbon dioxide concentrations during ripening: Incidence on final dry matter, total soluble solids content and acidity of mango fruit.

PubMed

Nordey, Thibault; Léchaudel, Mathieu; Génard, Michel; Joas, Jacques

2016-06-01

Ripening of climacteric fruits is associated with pronounced changes in fruit gas composition caused by a concomitant rise in respiration and ethylene production. There is a discrepancy in the literature since some authors reported that changes in fruit gas compositions differ in attached and detached fruits. This study presents for the first time an overview of pre- and post-harvest factors that lead to variations in the climacteric respiration and ethylene production, and attempts to determine their impacts on fruit composition, i.e., dry matter, total soluble solids content and acidity. The impact of growing conditions such as the fruit position in the canopy and the fruit carbon supply; fruit detachment from the tree, including the maturity stage at harvest; and storage conditions after harvest, i.e., relative humidity and temperature were considered as well as changes in fruit skin resistance to gas diffusion during fruit growth and storage. Results showed that fruit gas composition vary with all pre and post-harvest factors studied. Although all mangoes underwent a respiratory climacteric and an autocatalytic ethylene production, whatever pre and post-harvest factors studied, large differences in ethylene production, climacteric respiration and fruit quality were measured. Results suggested that the ripening capacity is not related to the fruit ability to produce great amount of ethylene. In agreement with precedent studies, this work provided several lines of evidence that gas composition of fruit is related to its water balance. Our measurements indicated that skin resistance to gas diffusion increased after the harvest and during storage. It was so suggested that the faster ripening of detached fruit may be explained in part by changes in fruit water balance and skin resistance to gas diffusion caused by fruit detachment. Copyright © 2016 Elsevier GmbH. All rights reserved.

Factors affecting the cement-post interface.

PubMed

Zicari, F; De Munck, J; Scotti, R; Naert, I; Van Meerbeek, B

2012-03-01

To evaluate the effect of different factors on the push-out bond strength of glass fiber posts luted in simulated (standard) root canals using different composite cements. Three types of glass-fiber root-canal posts with a different matrix, namely an epoxy resin (RelyX post, 3M ESPE), a proprietary composite resin (FRC-Plus post, Ivoclar-Vivadent), and a methacrylate resin (GC post, GC), and three types of composite cements, namely an etch-and-rinse Bis-GMA-based (Variolink II, Ivoclar-Vivadent), a self-etch 10-MDP-based (Clearfil Esthetic Cement, Kuraray) and a self-adhesive (RelyX Unicem, 3M ESPE) cement, were tested. Posts were either left untreated (control), were treated with silane, or coated with silicated alumina particles (Cojet system, 3M ESPE). Posts were inserted up to 9-mm depth into composite CAD-CAM blocks (Paradigm, 3M ESPE) in order to solely test the strength of the cement-post interface, while excluding interference of the cement-dentin interface. After 1-week storage at 37 °C, three sections (coronal, middle, apical) of 2-mm thickness were subjected to a push-out bond-strength test. All three variables, namely the type of post, the composite cement and the post-surface pre-treatment, were found to significantly affect the push-out bond strength (p<0.001). Regarding the type of post, a significantly lower push-out bond strength was recorded for the FRC-Plus post (Ivoclar-Vivadent); regarding the composite cement, a significantly higher push-out bond strength was recorded for the self-adhesive cement Unicem (3M ESPE); and regarding the post-surface treatment, a significantly higher push-out bond strength was recorded when the post-surface was beforehand subjected to a Cojet (3M ESPE) combined sandblasting/silicatization surface pre-treatment. Many interactions between these three variables were found to be significant as well (p<0.001). Finally, the push-out bond strength was found to significantly reduce with depth from coronal to apical. Laboratory testing revealed that different variables like the type of post, the composite cement and the post-surface pre-treatment may influence the cement-post interface, making clear guidelines for routine clinical practice hard to define. Further long-term durability testing may help to clarify, and should therefore be encouraged. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Differential effects of abiotic factors and host plant traits on diversity and community composition of root-colonizing arbuscular mycorrhizal fungi in a salt-stressed ecosystem.

PubMed

Guo, Xiaohong; Gong, Jun

2014-02-01

Arbuscular mycorrhizal fungi (AMF) were investigated in roots of 18 host plant species in a salinized south coastal plain of Laizhou Bay, China. From 18 clone libraries of 18S rRNA genes, all of the 22 AMF phylotypes were identified into Glomus, of which 18 and 4 were classified in group A and B in the phylogenetic tree, respectively. The phylotypes related to morphologically defined Glomus species occurred generally in soil with higher salinity. AMF phylotype richness, Shannon index, and evenness were not significantly different between root samples from halophytes vs. non-halophytes, invades vs. natives, or annuals vs. perennials. However, AMF diversity estimates frequently differed along the saline gradient or among locations, but not among pH gradients. Moreover, UniFrac tests showed that both plant traits (salt tolerance, life style or origin) and abiotic factors (salinity, pH, or location) significantly affected the community composition of AMF colonizers. Redundancy and variation partitioning analyses revealed that soil salinity and pH, which respectively explained 6.9 and 4.2 % of the variation, were the most influential abiotic variables in shaping the AMF community structure. The presented data indicate that salt tolerance, life style, and origin traits of host species may not significantly affect the AMF diversity in roots, but do influence the community composition in this salinized ecosystem. The findings also highlight the importance of soil salinity and pH in driving the distribution of AMF in plant and soil systems.

Proteome Evolution of Deep-Sea Hydrothermal Vent Alvinellid Polychaetes Supports the Ancestry of Thermophily and Subsequent Adaptation to Cold in Some Lineages

PubMed Central

Fontanillas, Eric; Galzitskaya, Oxana V.; Lecompte, Odile; Lobanov, Mikhail Y.; Tanguy, Arnaud; Mary, Jean; Girguis, Peter R.; Hourdez, Stéphane

2017-01-01

Temperature, perhaps more than any other environmental factor, is likely to influence the evolution of all organisms. It is also a very interesting factor to understand how genomes are shaped by selection over evolutionary timescales, as it potentially affects the whole genome. Among thermophilic prokaryotes, temperature affects both codon usage and protein composition to increase the stability of the transcriptional/translational machinery, and the resulting proteins need to be functional at high temperatures. Among eukaryotes less is known about genome evolution, and the tube-dwelling worms of the family Alvinellidae represent an excellent opportunity to test hypotheses about the emergence of thermophily in ectothermic metazoans. The Alvinellidae are a group of worms that experience varying thermal regimes, presumably having evolved into these niches over evolutionary times. Here we analyzed 423 putative orthologous loci derived from 6 alvinellid species including the thermophilic Alvinella pompejana and Paralvinella sulfincola. This comparative approach allowed us to assess amino acid composition, codon usage, divergence, direction of residue changes and the strength of selection along the alvinellid phylogeny, and to design a new eukaryotic thermophilic criterion based on significant differences in the residue composition of proteins. Contrary to expectations, the alvinellid ancestor of all present-day species seems to have been thermophilic, a trait subsequently maintained by purifying selection in lineages that still inhabit higher temperature environments. In contrast, lineages currently living in colder habitats likely evolved under selective relaxation, with some degree of positive selection for low-temperature adaptation at the protein level. PMID:28082607

The influence of beverage composition on delivery of phenolic compounds from coffee and tea.

PubMed

Ferruzzi, Mario G

2010-04-26

Epidemiological data suggest that consumption of coffee and tea is associated with a reduced risk of several chronic and degenerative diseases including cardiovascular disorders, diabetes, obesity and neurodegenerative disorders. Both coffee and tea are a rich source of phenolic compounds including chlorogenic acids in coffee; and flavan-3-ols as well as complex theaflavins and thearubigens in tea. Coffee and tea are two of the most commonly consumed beverages in the world and thus represent a significant opportunity to positively affect disease risk and outcomes globally. Central to this opportunity is a need to better understand factors that may affect the bioavailability of specific phenolic components from coffee and tea based beverages. An overview of the phenolic composition of coffee and tea is discussed in the context of how processing and composition might influence phenolic profiles and bioavailability of individual phenolic components. Specifically, the impact of beverage formulation, the extent and type of processing and the influence of digestion on stability, bioavailability and metabolism of bioactive phenolics from tea and coffee are discussed. The impact of co-formulation with ascorbic acid and other phytochemicals are discussed as strategies to improve absorption of these health promoting phytochemicals. A better understanding of how the beverage composition impacts phenolic profiles and their bioavailability is critical to development of beverage products designed to deliver specific health benefits. Copyright 2010 Elsevier Inc. All rights reserved.

Fatty acid profiles of great tit (Parus major) eggs differ between urban and rural habitats, but not between coniferous and deciduous forests.

PubMed

Toledo, Alejandra; Andersson, Martin N; Wang, Hong-Lei; Salmón, Pablo; Watson, Hannah; Burdge, Graham C; Isaksson, Caroline

2016-08-01

Early-life nutrition is an important determinant of both short- and long-term performance and fitness. The avian embryo develops within an enclosed package of nutrients, of which fatty acids (FA) are essential for many aspects of development. The FA composition of yolk depends on maternal nutrition and condition prior to egg formation, which may be affected by the external environment. To test if maternal environment affects yolk FA composition, we investigated whether the FA composition of great tit (Parus major) egg yolks differed between urban and rural habitats, and between deciduous and coniferous habitats. The results reveal differences in FA composition between eggs laid in urban and rural habitats, but not between eggs from the coniferous and deciduous habitats. To a large extent, this difference likely reflects dietary differences associated with urban habitats rather than dominating vegetation type. Specifically, urban yolks contained lower proportions of both ω-3 and ω-6 polyunsaturated FAs (PUFA), which are important for chick development. We also found a positive association between the proportion of saturated fatty acids and laying date, and a negative association between the proportion of ω-6 PUFA and clutch size. Given that urbanization is expanding rapidly, future studies should investigate whether factors such as anthropogenic food in the urban environment underlie these differences and whether they impair chick development.

Temporal and Spatial Variation of Soil Bacteria Richness, Composition, and Function in a Neotropical Rainforest

PubMed Central

Kivlin, Stephanie N; Hawkes, Christine V

2016-01-01

The high diversity of tree species has traditionally been considered an important controller of belowground processes in tropical rainforests. However, soil water availability and resources are also primary regulators of soil bacteria in many ecosystems. Separating the effects of these biotic and abiotic factors in the tropics is challenging because of their high spatial and temporal heterogeneity. To determine the drivers of tropical soil bacteria, we examined tree species effects using experimental tree monocultures and secondary forests at La Selva Biological Station in Costa Rica. A randomized block design captured spatial variation and we sampled at four dates across two years to assess temporal variation. We measured bacteria richness, phylogenetic diversity, community composition, biomass, and functional potential. All bacteria parameters varied significantly across dates. In addition, bacteria richness and phylogenetic diversity were affected by the interaction of vegetation type and date, whereas bacteria community composition was affected by the interaction of vegetation type and block. Shifts in bacteria community richness and composition were unrelated to shifts in enzyme function, suggesting physiological overlap among taxa. Based on the observed temporal and spatial heterogeneity, our understanding of tropical soil bacteria will benefit from additional work to determine the optimal temporal and spatial scales for sampling. Understanding spatial and temporal variation will facilitate prediction of how tropical soil microbes will respond to future environmental change. PMID:27391450

Temporal and Spatial Variation of Soil Bacteria Richness, Composition, and Function in a Neotropical Rainforest.

PubMed

Kivlin, Stephanie N; Hawkes, Christine V

2016-01-01

The high diversity of tree species has traditionally been considered an important controller of belowground processes in tropical rainforests. However, soil water availability and resources are also primary regulators of soil bacteria in many ecosystems. Separating the effects of these biotic and abiotic factors in the tropics is challenging because of their high spatial and temporal heterogeneity. To determine the drivers of tropical soil bacteria, we examined tree species effects using experimental tree monocultures and secondary forests at La Selva Biological Station in Costa Rica. A randomized block design captured spatial variation and we sampled at four dates across two years to assess temporal variation. We measured bacteria richness, phylogenetic diversity, community composition, biomass, and functional potential. All bacteria parameters varied significantly across dates. In addition, bacteria richness and phylogenetic diversity were affected by the interaction of vegetation type and date, whereas bacteria community composition was affected by the interaction of vegetation type and block. Shifts in bacteria community richness and composition were unrelated to shifts in enzyme function, suggesting physiological overlap among taxa. Based on the observed temporal and spatial heterogeneity, our understanding of tropical soil bacteria will benefit from additional work to determine the optimal temporal and spatial scales for sampling. Understanding spatial and temporal variation will facilitate prediction of how tropical soil microbes will respond to future environmental change.

Fatty acid profiles of great tit ( Parus major) eggs differ between urban and rural habitats, but not between coniferous and deciduous forests

NASA Astrophysics Data System (ADS)

Toledo, Alejandra; Andersson, Martin N.; Wang, Hong-Lei; Salmón, Pablo; Watson, Hannah; Burdge, Graham C.; Isaksson, Caroline

2016-08-01

Early-life nutrition is an important determinant of both short- and long-term performance and fitness. The avian embryo develops within an enclosed package of nutrients, of which fatty acids (FA) are essential for many aspects of development. The FA composition of yolk depends on maternal nutrition and condition prior to egg formation, which may be affected by the external environment. To test if maternal environment affects yolk FA composition, we investigated whether the FA composition of great tit ( Parus major) egg yolks differed between urban and rural habitats, and between deciduous and coniferous habitats. The results reveal differences in FA composition between eggs laid in urban and rural habitats, but not between eggs from the coniferous and deciduous habitats. To a large extent, this difference likely reflects dietary differences associated with urban habitats rather than dominating vegetation type. Specifically, urban yolks contained lower proportions of both ω-3 and ω-6 polyunsaturated FAs (PUFA), which are important for chick development. We also found a positive association between the proportion of saturated fatty acids and laying date, and a negative association between the proportion of ω-6 PUFA and clutch size. Given that urbanization is expanding rapidly, future studies should investigate whether factors such as anthropogenic food in the urban environment underlie these differences and whether they impair chick development.

Controlled ecological life support system - biological problems

NASA Technical Reports Server (NTRS)

Moore, B., III (Editor); Macelroy, R. D. (Editor)

1982-01-01

The general processes and controls associated with two distinct experimental paradigms are examined. Specific areas for research related to biotic production (food production) and biotic decomposition (waste management) are explored. The workshop discussions were directed toward Elemental cycles and the biological factors that affect the transformations of nutrients into food, of food material into waste, and of waste into nutrients were discussed. To focus on biological issues, the discussion assumed that (1) food production would be by biological means (thus excluding chemical synthesis), (2) energy would not be a limiting factor, and (3) engineering capacity for composition and leak rate would be adequate.

Chronic human disturbance affects plant trait distribution in a seasonally dry tropical forest

NASA Astrophysics Data System (ADS)

Sfair, Julia C.; de Bello, Francesco; de França, Thaysa Q.; Baldauf, Cristina; Tabarelli, Marcelo

2018-02-01

The effects of human disturbance on biodiversity can be mediated by environmental conditions, such as water availability, climate and nutrients. In general, disturbed, dry or nutrient-depleted soils areas tend to have lower taxonomic diversity. However, little is known about how these environmental conditions affect functional composition and intraspecific variability in tropical dry forests. We studied a seasonally dry tropical forest (SDTF) under chronic anthropogenic disturbance (CAD) along rainfall and soil nutrient gradients to understand how these factors influence the taxonomic and functional composition. Specifically we evaluated two aspects of CAD, wood extraction and livestock pressure (goat and cattle grazing), along soil fertility and rainfall gradients on shrub and tree traits, considering species turnover and intraspecific variability. In addition, we also tested how the traits of eight populations of the most frequent species are affected by wood extraction, livestock pressure, rainfall and soil fertility. In general, although CAD and environmental gradients affected each trait of the most widespread species differently, the most abundant species also had a greater variation of traits. Considering species turnover, wood extraction is associated with species with a smaller leaf area and lower investment in leaf mass, probably due to the indirect effects of this disturbance type on the vegetation, i.e. the removal of branches and woody debris clears the vegetation, favouring species that minimize water loss. Livestock pressure, on the other hand, affected intraspecific variation: the herbivory caused by goats and cattle promoted individuals which invest more in wood density and leaf mass. In this case, the change of functional composition observed is a direct effect of the disturbance, such as the decrease of palatable plant abundance by goat and cattle herbivory. In synthesis, CAD, rainfall and soil fertility can affect trait distribution at community and species levels, which can have significant implications for the ecosystem functioning of SDTF under increasing levels of disturbance, climate change and soil nutrient depletion.

Analyzing the Effects of Climate Factors on Soybean Protein, Oil Contents, and Composition by Extensive and High-Density Sampling in China.

PubMed

Song, Wenwen; Yang, Ruping; Wu, Tingting; Wu, Cunxiang; Sun, Shi; Zhang, Shouwei; Jiang, Bingjun; Tian, Shiyan; Liu, Xiaobing; Han, Tianfu

2016-05-25

From 2010 to 2013, 763 soybean samples were collected from an extensive area of China. The correlations between seed compositions and climate data were analyzed. The contents of crude protein and water-soluble protein, total amount of protein plus oil, and most of the amino acids were positively correlated with an accumulated temperature ≥15 °C (AT15) and the mean daily temperature (MDT) but were negatively correlated with hours of sunshine (HS) and diurnal temperature range (DTR). The correlations of crude oil and most fatty acids with climate factors were opposite to those of crude protein. Crude oil content had a quadratic regression relationship with MDT, and a positive correlation between oil content and MDT was found when the daily temperature was <19.7 °C. A path analysis indicated that DTR was the main factor that directly affected soybean protein and oil contents. The study illustrated the effects of climate factors on soybean protein and oil contents and proposed agronomic practices for improving soybean quality in different regions of China. The results provide a foundation for the regionalization of high-quality soybean production in China and similar regions in the world.

Metabolomic unveiling of a diverse range of green tea (Camellia sinensis) metabolites dependent on geography.

PubMed

Lee, Jang-Eun; Lee, Bum-Jin; Chung, Jin-Oh; Kim, Hak-Nam; Kim, Eun-Hee; Jung, Sungheuk; Lee, Hyosang; Lee, Sang-Jun; Hong, Young-Shick

2015-05-01

Numerous factors such as geographical origin, cultivar, climate, cultural practices, and manufacturing processes influence the chemical compositions of tea, in the same way as growing conditions and grape variety affect wine quality. However, the relationships between these factors and tea chemical compositions are not well understood. In this study, a new approach for non-targeted or global analysis, i.e., metabolomics, which is highly reproducible and statistically effective in analysing a diverse range of compounds, was used to better understand the metabolome of Camellia sinensis and determine the influence of environmental factors, including geography, climate, and cultural practices, on tea-making. We found a strong correlation between environmental factors and the metabolome of green, white, and oolong teas from China, Japan, and South Korea. In particular, multivariate statistical analysis revealed strong inter-country and inter-city relationships in the levels of theanine and catechin derivatives found in green and white teas. This information might be useful for assessing tea quality or producing distinct tea products across different locations, and highlights simultaneous identification of diverse tea metabolites through an NMR-based metabolomics approach. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of factors affecting failure of glass cermet tunnel restorations in a multi-center study.

PubMed

Pilebro, C E; van Dijken, J W

2001-06-01

The aim of this study was to analyze factors influencing the failures of tunnel restorations performed with a glass cermet cement (Ketac Silver). Caries activity, lesion size, tunnel cavity opening size, partial or total tunnel, composite lamination or operating time showed no significant correlation to failure rate. Twelve dentists in eight clinics clinically experienced and familiar with the tunnel technique placed 374 restorations. The occlusal sections of fifty percent of the restorations were laminated with hybrid resin composite. The results of the yearly clinical and radiographic evaluations over the course of 3 years were correlated to factors that could influence the failure rate using logistic regression analysis. At the 3-year recall a cumulative number of 305 restorations were available. The cumulative replacement rate was 20%. The main reasons for replacement were marginal ridge fracture (14%) and dentin caries (3%). Another 7% of the restorations which had not been replaced were classified as failures because of untreated dentin caries. The only significant variable observed was the individual failure rate of the participating dentists varying between 9 and 50% (p=0.013).

Antinutritional factors and functionality of protein-rich fractions of industrial guar meal as affected by heat processing.

PubMed

Nidhina, N; Muthukumar, S P

2015-04-15

Proximate composition analysis and antinutritional factor composition of different fractions of industrial guar meal: raw churi (IRC), heated churi (IHC), final churi (IFC) and guar korma (IGK) were studied and compared. Protein content was found to be very high in IGK (52.7%) when compared to the churi fractions (32-33%) and the trypsin inhibitor activities were found to be negligible in all the fractions (0.58-1.8 mg/g). Single fraction (IGK) was selected for further studies, based on the protein content. The antinutritional factors of selected fractions were significantly reduced by different heat treatments. Heat treatments significantly increased the water absorbing capacity of IGK, but reduced the nitrogen solubility, emulsifying and foaming capacity. Highest L(∗) value was observed for boiled IGK, highest a(∗) and b(∗) values for roasted IGK, during colour measurement. FTIR spectral analysis revealed the presence several aromatic groups in IGK and slight modifications in the molecular structure during heat treatments. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbial diversity in innovative mesophilic/thermophilic temperature-phased anaerobic digestion of sludge.

PubMed

Gagliano, M C; Braguglia, C M; Gallipoli, A; Gianico, A; Rossetti, S

2015-05-01

Anaerobic digestion (AD) is one of the few sustainable technologies that both produce energy and treat waste streams. Driven by a complex and diverse community of microbes, AD may be affected by different factors, many of which also influence the composition and activity of the microbial community. In this study, the biodiversity of microbial populations in innovative mesophilic/thermophilic temperature-phased AD of sludge was evaluated by means of fluorescence in situ hybridization (FISH). The increase of digestion temperature drastically affected the microbial composition and selected specialized biomass. Hydrogenotrophic Methanobacteriales and the protein fermentative bacterium Coprothermobacter spp. were identified in the thermophilic anaerobic biomass. Shannon-Weaver diversity (H') and evenness (E) indices were calculated using FISH data. Species richness was lower under thermophilic conditions compared with the values estimated in mesophilic samples, and it was flanked by similar trend of the evenness indicating that thermophilic communities may be therefore more susceptible to sudden changes and less prompt to adapting to operative variations.

Optimization of electrocoagulation process for the treatment of landfill leachate

NASA Astrophysics Data System (ADS)

Huda, N.; Raman, A. A.; Ramesh, S.

2017-06-01

The main problem of landfill leachate is its diverse composition comprising of persistent organic pollutants (POPs) which must be removed before being discharge into the environment. In this study, the treatment of leachate using electrocoagulation (EC) was investigated. Iron was used as both the anode and cathode. Response surface methodology was used for experimental design and to study the effects of operational parameters. Central Composite Design was used to study the effects of initial pH, inter-electrode distance, and electrolyte concentration on color, and COD removals. The process could remove up to 84 % color and 49.5 % COD. The experimental data was fitted onto second order polynomial equations. All three factors were found to be significantly affect the color removal. On the other hand, electrolyte concentration was the most significant parameter affecting the COD removal. Numerical optimization was conducted to obtain the optimum process performance. Further work will be conducted towards integrating EC with other wastewater treatment processes such as electro-Fenton.

Effects of Plant Diversity, Functional Group Composition, and Fertilization on Soil Microbial Properties in Experimental Grassland

PubMed Central

Strecker, Tanja; Barnard, Romain L.; Niklaus, Pascal A.; Scherer-Lorenzen, Michael; Weigelt, Alexandra; Scheu, Stefan; Eisenhauer, Nico

2015-01-01

Background Loss of biodiversity and increased nutrient inputs are two of the most crucial anthropogenic factors driving ecosystem change. Although both received considerable attention in previous studies, information on their interactive effects on ecosystem functioning is scarce. In particular, little is known on how soil biota and their functions are affected by combined changes in plant diversity and fertilization. Methodology/Principal Findings We investigated the effects of plant diversity, functional community composition, and fertilization on the biomass and respiration of soil microbial communities in a long-term biodiversity experiment in semi-natural grassland (Jena Experiment). Plant species richness enhanced microbial basal respiration and microbial biomass, but did not significantly affect microbial specific respiration. In contrast, the presence of legumes and fertilization significantly decreased microbial specific respiration, without altering microbial biomass. The effect of legumes was superimposed by fertilization as indicated by a significant interaction between the presence of legumes and fertilization. Further, changes in microbial stoichiometry (C-to-N ratio) and specific respiration suggest the presence of legumes to reduce N limitation of soil microorganisms and to modify microbial C use efficiency. Conclusions/Significance Our study highlights the role of plant species and functional group diversity as well as interactions between plant community composition and fertilizer application for soil microbial functions. Our results suggest soil microbial stoichiometry to be a powerful indicator of microbial functioning under N limited conditions. Although our results support the notion that plant diversity and fertilizer application independently affect microbial functioning, legume effects on microbial N limitation were superimposed by fertilization, indicating significant interactions between the functional composition of plant communities and nutrient inputs for soil processes. PMID:25938580

Relationship between wine composition and temperature: Impact on Bordeaux wine typicity in the context of global warming-Review.

PubMed

Drappier, Julie; Thibon, Cécile; Rabot, Amélie; Geny-Denis, Laurence

2017-10-24

Weather conditions throughout the year have a greater influence than other factors (such as soil and cultivars) on grapevine development and berry composition. Temperature affects gene expression and enzymatic activity of primary and secondary metabolism which determine grape ripening and wine characteristics. In the context of the climate change, temperatures will probably rise between 0.3°C and 1.7°C over the next 20 years. They are already rising and the physiology of grapevines is already changing. These modifications exert a profound shift in primary (sugar and organic acid balance) and secondary (phenolic and aromatic compounds) berry metabolisms and the resulting composition of wine. For example, some Bordeaux wines have a tendency toward reduced freshness and a modification of their ruby color. In this context it is necessary to understand the impact of higher temperatures on grape development, harvest procedures, and wine composition in order to preserve the typicity of the wines and to adapt winemaking processes.

Effects of filler type and content on mechanical properties of photopolymerizable composites measured across two-dimensional combinatorial arrays.

PubMed

Lin-Gibson, Sheng; Sung, Lipiin; Forster, Aaron M; Hu, Haiqing; Cheng, Yajun; Lin, Nancy J

2009-07-01

Multicomponent formulations coupled with complex processing conditions govern the final properties of photopolymerizable dental composites. In this study, a single test substrate was fabricated to support multiple formulations with a gradient in degree of conversion (DC), allowing the evaluation of multiple processing conditions and formulations on one specimen. Mechanical properties and damage response were evaluated as a function of filler type/content and irradiation. DC, surface roughness, modulus, hardness, scratch deformation and cytotoxicity were quantified using techniques including near-infrared spectroscopy, laser confocal scanning microscopy, depth-sensing indentation, scratch testing and cell viability. Scratch parameters (depth, width, percent recovery) were correlated to composite modulus and hardness. Total filler content, nanofiller and irradiation time/intensity all affected the final properties, with the dominant factor for improved properties being a higher DC. This combinatorial platform accelerates the screening of dental composites through the direct comparison of properties and processing conditions across the same sample.

Hydro-edaphic conditions defining richness and species composition in savanna areas of the northern Brazilian Amazonia.

PubMed

Araújo, Maria Aparecida de Moura; da Rocha, Antônio Elielson Sousa; Miranda, Izildinha de Souza; Barbosa, Reinaldo Imbrozio

2017-01-01

Studies on plant communities in the Amazon have reported that different hydro-edaphic conditions can affect the richness and the species composition of different ecosystems. However, this aspect is poorly known in the different savanna habitats. Understanding how populations and plant communities are distributed in these open vegetation areas is important to improve the knowledge about which environmental variables influence the occurrence and diversity of plants in this type of regional ecosystem. Thus, this study investigated the richness and composition of plant species in two savanna areas of the northern Brazilian Amazonia, using the coverage (%) of the different life forms observed under different hydro-edaphic conditions as a structural reference. We report 128 plant species classified in 34 botanical families distributed in three savanna habitats with different levels of hydro-edaphic restrictions. In this study, the habitats are conceptually presented and they integrate environmental information (edaphic factors and drainage type), which determines differences between floristic composition, species richness and coverage (%) of plant life forms.

Effect of cultivar on phenolic levels, anthocyanin composition, and antioxidant properties in purple basil (Ocimum basilicum L.).

PubMed

Flanigan, Patrick M; Niemeyer, Emily D

2014-12-01

In this study, we determined the effect of cultivar on total and individual anthocyanin concentrations and phenolic acid levels in eight purple basil varieties and examined the relationship between anthocyanin content, phenolic acid composition, and antioxidant properties. Cultivar had a significant influence on total anthocyanin concentrations as well as individual anthocyanin composition. The four major basil anthocyanins (labelled A-D) were quantified and cultivar had a statistically significant effect on anthocyanins B (p<0.01), C (p<0.01), and D (p<0.01), but not on anthocyanin A (p=0.94). Cultivar did not have a significant effect on total phenolic levels, although it did influence the concentration of some individual phenolic acids, including caftaric (p=0.03) and chicoric (p=0.04) acids. Although total phenolic and anthocyanin levels correlated with measured FRAP antioxidant capacities, for some cultivars the individual phenolic acid and anthocyanin composition was also an important factor affecting the antioxidant properties. Copyright © 2014 Elsevier Ltd. All rights reserved.

Surface Properties and Permeability of Poly(Vinylidene Fluoride)-Clays (PVDF/Clays) Composite Membranes

NASA Astrophysics Data System (ADS)

Pramono, E.; Ahdiat, M.; Simamora, A.; Pratiwi, W.; Radiman, C. L.; Wahyuningrum, D.

2017-07-01

Surface properties are important factors that determine the performance of ultrafiltration membranes. This study aimed to investigate the effects of clay addition on the surface properties and membrane permeability of PVDF (poly-vinylidene fluoride) membranes. Three types of clay with different particle size were used in this study, namely montmorillonite-MMT, bentonite-BNT and cloisite 15A-CLS. The PVDF-clay composite membranes were prepared by phase inversion method using PEG as additive. The hydrophobicity of membrane surface was characterized by contact angle. The membrane permeability was determined by dead- end ultrafiltration with a trans-membrane pressure of 2 bars. In contact angle measurement, water contact angle of composite membranes is higher than PVDF membrane. The addition of clays decreased water flux but increased of Dextran rejection. The PVDF-BNT composite membranes reach highest Dextran rejection value of about 93%. The type and particle size of clay affected the hydrophobicity of membrane surface and determined the resulting membrane structure as well as the membrane performance.

Analytical and experimental investigation of aircraft metal structures reinforced with filamentary composites. Phase 2: Structural fatigue, thermal cycling, creep, and residual strength

NASA Technical Reports Server (NTRS)

Blichfeldt, B.; Mccarty, J. E.

1972-01-01

Specimens representative of metal aircraft structural components reinforced with boron filamentary composites were manufactured and tested under cyclic loading, cyclic temperature, or continuously applied loading to evaluate some of the factors that affect structural integrity under cyclic conditions. Bonded, stepped joints were used throughout to provide composite-to-metal transition regions at load introduction points. Honeycomb panels with titanium or aluminum faces reinforced with unidirectional boron composite were fatigue tested at constant amplitude under completely reversed loading. Results indicated that the matrix material was the most fatigue-sensitive part of the design, with debonding initiating in the stepped joints. However, comparisons with equal weight all-metal specimens show a 10 to 50 times improved fatigue life. Fatigue crack propagation and residual strength were studied for several different stiffened panel concepts, and were found to vary considerably depending on the configuration. Composite-reinforced metal specimens were also subjected to creep and thermal cycling tests. Thermal cycling of stepped joint tensile specimens resulted in a ten percent decrease in residual strength after 4000 cycles.

Interfacial effect on physical properties of composite media: Interfacial volume fraction with non-spherical hard-core-soft-shell-structured particles.

PubMed

Xu, Wenxiang; Duan, Qinglin; Ma, Huaifa; Chen, Wen; Chen, Huisu

2015-11-02

Interfaces are known to be crucial in a variety of fields and the interfacial volume fraction dramatically affects physical properties of composite media. However, it is an open problem with great significance how to determine the interfacial property in composite media with inclusions of complex geometry. By the stereological theory and the nearest-surface distribution functions, we first propose a theoretical framework to symmetrically present the interfacial volume fraction. In order to verify the interesting generalization, we simulate three-phase composite media by employing hard-core-soft-shell structures composed of hard mono-/polydisperse non-spherical particles, soft interfaces, and matrix. We numerically derive the interfacial volume fraction by a Monte Carlo integration scheme. With the theoretical and numerical results, we find that the interfacial volume fraction is strongly dependent on the so-called geometric size factor and sphericity characterizing the geometric shape in spite of anisotropic particle types. As a significant interfacial property, the present theoretical contribution can be further drawn into predicting the effective transport properties of composite materials.

Interfacial effect on physical properties of composite media: Interfacial volume fraction with non-spherical hard-core-soft-shell-structured particles

PubMed Central

Xu, Wenxiang; Duan, Qinglin; Ma, Huaifa; Chen, Wen; Chen, Huisu

2015-01-01

Interfaces are known to be crucial in a variety of fields and the interfacial volume fraction dramatically affects physical properties of composite media. However, it is an open problem with great significance how to determine the interfacial property in composite media with inclusions of complex geometry. By the stereological theory and the nearest-surface distribution functions, we first propose a theoretical framework to symmetrically present the interfacial volume fraction. In order to verify the interesting generalization, we simulate three-phase composite media by employing hard-core-soft-shell structures composed of hard mono-/polydisperse non-spherical particles, soft interfaces, and matrix. We numerically derive the interfacial volume fraction by a Monte Carlo integration scheme. With the theoretical and numerical results, we find that the interfacial volume fraction is strongly dependent on the so-called geometric size factor and sphericity characterizing the geometric shape in spite of anisotropic particle types. As a significant interfacial property, the present theoretical contribution can be further drawn into predicting the effective transport properties of composite materials. PMID:26522701

Changes in body composition of high competition rugby players during the phases of a regular season; influence of diet and exercise load.

PubMed

García, M; Martínez-Moreno, J M; Reyes-Ortiz, A; Suarez Moreno-Arrones, L; García A, A; Garcíacaballero, M

2014-04-01

Top athletes are subjected to intense training to achieve high performance. There are factors such as diet and strenuous exercise that affects body composition and can modify the performance. The aim of the study was to evaluate the effect of a personalized plan of diet and training on body composition. We studied the body composition of 18 professional rugby players using Kinanthropometry parameters. The study was conducted from the preseason to the end of the season taking into account the position of the player for measuring exercise intensity, and developing a personalized nutritional and training plan to each player. At baseline the players were away from the internationally recommended body composition, with high percentages of body fat. Appropriate and personalized diet plans and training custom achieved fat percentages close to those recommended. The personalized program of diet and training directed has adequate leverage to improve all parameters studied them bringing them as close to the ideal. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Biological underpinnings of breastfeeding challenges: the role of genetics, diet, and environment on lactation physiology

PubMed Central

Lee, Sooyeon

2016-01-01

Lactation is a dynamic process that has evolved to produce a complex biological fluid that provides nutritive and nonnutritive factors to the nursing offspring. It has long been assumed that once lactation is successfully initiated, the primary factor regulating milk production is infant demand. Thus, most interventions have focused on improving breastfeeding education and early lactation support. However, in addition to infant demand, increasing evidence from studies conducted in experimental animal models, production animals, and breastfeeding women suggests that a diverse array of maternal factors may also affect milk production and composition. In this review, we provide an overview of our current understanding of the role of maternal genetics and modifiable factors, such as diet and environmental exposures, on reproductive endocrinology, lactation physiology, and the ability to successfully produce milk. To identify factors that may affect lactation in women, we highlight some information gleaned from studies in experimental animal models and production animals. Finally, we highlight the gaps in current knowledge and provide commentary on future research opportunities aimed at improving lactation outcomes in breastfeeding women to improve the health of mothers and their infants. PMID:27354238

Effect of litter, leaf cover and cover of basal internodes of the dominant species Molinia caerulea on seedling recruitment and established vegetation

NASA Astrophysics Data System (ADS)

Janeček, Štěpán; Lepš, Jan

2005-09-01

The effects of litter removal, leaf cover of established plants and cover of basal internodes of a dominant species Molinia caerulea on seedling germination and the dynamics of established plants were studied in a field experiment in an oligotrophic wet meadow. Although the negative influence of litter on total seedling number and seedling species composition was non-significant, litter significantly affected the dynamics of the established vegetation and caused inhibition of total leaf cover development. The effects of total leaf cover of established plants on seedling establishment changed during the vegetation season. Whereas the effect of total leaf cover was positive at the start and in the middle of the vegetation season, at the end the total leaf cover negatively affected seedling establishment. Both total leaf cover and cover of basal internodes affected seedling composition. Effects of these two variables were statistically separable suggesting that they are based on different mechanisms. The response of seedling establishment to these factors was species specific and, consequently, our data support the hypothesis that that biotically generated spatial heterogeneity can promote species co-existence through the differentiation of species regeneration niches.

Energy composition of diet affects muscle fiber recruitment, body composition, and growth trajectory in rainbow trout (Oncorhnychus mykiss)

USDA-ARS?s Scientific Manuscript database

Energy composition of diet affects muscle fiber recruitment, body composition, and growth trajectory in rainbow trout (Oncorhnychus mykiss) The cost and scarcity of key ingredients for aquaculture feed formulation call for a wise use of resources, especially dietary proteins and energy. For years t...

Herbivores, tidal elevation, and species richness simultaneously mediate nitrate uptake by seaweed assemblages.

PubMed

Bracken, Matthew E S; Jones, Emily; Williams, Susan L

2011-05-01

In order for research into the consequences of biodiversity changes to be more applicable to real-world ecosystems, experiments must be conducted in the field, where a variety of factors other than diversity can affect the rates of key biogeochemical and physiological processes. Here, we experimentally evaluate the effects of two factors known to affect the diversity and composition of intertidal seaweed assemblages--tidal elevation and herbivory--on nitrate uptake by those assemblages. Based on surveys of community composition at the end of a 1.5-year press experiment, we found that both tide height and herbivores affected seaweed community structure. Not surprisingly, seaweed species richness was greater at lower tidal elevations. Herbivores did not affect richness, but they altered the types of species that were present; seaweed species characterized by higher rates of nitrate uptake were more abundant in herbivore-removal plots. Both tide height and herbivores affected nitrate uptake by seaweed assemblages. Individual seaweed species, as well as entire seaweed assemblages, living higher on the shore had greater rates of biomass-specific nitrate uptake, particularly at high ambient nitrate concentrations. Grazed seaweed assemblages exhibited reduced nitrate uptake, but only at low nitrate concentrations. We evaluated the effect of seaweed richness on nitrate uptake, both alone and after accounting for effects of tidal elevation and herbivores. When only richness was considered, we found no effect on uptake. However, when simultaneous effects of richness, tide height, and herbivores on uptake were evaluated, we found that all three had relatively large and comparable effects on nitrate uptake coefficients and that there was a negative relationship between seaweed richness and nitrate uptake. Particularly because effects of richness on uptake were not apparent unless the effects of tide height and herbivory were also considered, these results highlight the importance of considering the effects of environmental context when evaluating the consequences of biodiversity change in more realistic systems.

Variation in Protein Intake Induces Variation in Spider Silk Expression

PubMed Central

Blamires, Sean J.; Wu, Chun-Lin; Tso, I-Min

2012-01-01

Background It is energetically expensive to synthesize certain amino acids. The proteins (spidroins) of spider major ampullate (MA) silk, MaSp1 and MaSp2, differ in amino acid composition. Glutamine and proline are prevalent in MaSp2 and are expensive to synthesize. Since most orb web spiders express high proline silk they might preferentially attain the amino acids needed for silk from food and shift toward expressing more MaSp1 in their MA silk when starved. Methodology/Principal Findings We fed three spiders; Argiope aetherea, Cyrtophora moluccensis and Leucauge blanda, high protein, low protein or no protein solutions. A. aetherea and L. blanda MA silks are high in proline, while C. moluccesnsis MA silks are low in proline. After 10 days of feeding we determined the amino acid compositions and mechanical properties of each species' MA silk and compared them between species and treatments with pre-treatment samples, accounting for ancestry. We found that the proline and glutamine of A. aetherea and L. blanda silks were affected by protein intake; significantly decreasing under the low and no protein intake treatments. Glutmaine composition in C. moluccensis silk was likewise affected by protein intake. However, the composition of proline in their MA silk was not significantly affected by protein intake. Conclusions Our results suggest that protein limitation induces a shift toward different silk proteins with lower glutamine and/or proline content. Contradictions to the MaSp model lie in the findings that C. moluccensis MA silks did not experience a significant reduction in proline and A. aetherea did not experience a significant reduction in serine on low/no protein. The mechanical properties of the silks could not be explained by a MaSp1 expressional shift. Factors other than MaSp expression, such as the expression of spidroin-like orthologues, may impact on silk amino acid composition and spinning and glandular processes may impact mechanics. PMID:22363691

Decomposition of Phragmites australis rhizomes in artificial land-water transitional zones (ALWTZs) and management implications

NASA Astrophysics Data System (ADS)

Han, Zhen; Cui, Baoshan; Zhang, Yongtao

2015-09-01

Rhizomes are essential organs for growth and expansion of Phragmites australis. They function as an important source of organic matter and as a nutrient source, especially in the artificial land-water transitional zones (ALWTZs) of shallow lakes. In this study, decomposition experiments on 1- to 6-year-old P. australis rhizomes were conducted in the ALWTZ of Lake Baiyangdian to evaluate the contribution of the rhizomes to organic matter accumulation and nutrient release. Mass loss and changes in nutrient content were measured after 3, 7, 15, 30, 60, 90, 120, and 180 days. The decomposition process was modeled with a composite exponential model. The Pearson correlation analysis was used to analyze the relationships between mass loss and litter quality factors. A multiple stepwise regression model was utilized to determine the dominant factors that affect mass loss. Results showed that the decomposition rates in water were significantly higher than those in soil for 1- to 6-year-old rhizomes. However, the sequence of decomposition rates was identical in both water and soil. Significant relationships between mass loss and litter quality factors were observed at a later stage, and P-related factors proved to have a more significant impact than N-related factors on mass loss. According to multiple stepwise models, the C/P ratio was found to be the dominant factor affecting the mass loss in water, and the C/N and C/P ratios were the main factors affecting the mass loss in soil. The combined effects of harvesting, ditch broadening, and control of water depth should be considered for lake administrators.

Weathering Patterns of Forensic Biomarker Compounds and PAHs in Coastal Marsh Sediment Samples since the 2010 Deepwater Horizon Oil Spill

NASA Astrophysics Data System (ADS)

Overton, E. B.; Meyer, B.; Miles, S.; Olson, G.; Adhikari, P. L.

2016-02-01

It has been well established that the composition of oil, when spilled into the marine environment, undergoes substantial changes caused by weathering. The general sequence of this compositional change begins with straight chain alkanes (the fastest to degrade), followed by low molecular weight branched and cyclic alkanes and, finally the aromatics. Most resistant to weathering are the higher molecular weight cyclic and branched alkanes (i.e., the "forensic biomarker compounds" such as the hopanes and steranes) and tri-aromatic ringed steroids. The composition of these biomarker compounds is particularly resistant to change because they are not affected by evaporative weathering, are not water soluble, and are not readily degraded by microbial and/or photo-oxidation. However, after extensive time in the environment, being subjected to numerous weathering factors, biomarker compositional patterns are beginning to exhibit significant changes. This presentation will describe the general weathering patterns of petroleum residues in sediment samples collected from marsh areas of coastal Louisiana over a five year period. Particular attention will focus on compositional changes that have been observed in the steranes and diasteranes compounds that traditionally have been considered the most resistant to compositional changes due to weathering.

The effects of biotic and abiotic factors on the spatial heterogeneity of alpine grassland vegetation at a small scale on the Qinghai-Tibet Plateau (QTP), China.

PubMed

Wen, Lu; Dong, Shi Kui; Li, Yuan Yuan; Sherman, Ruth; Shi, Jian Jun; Liu, De Mei; Wang, Yan Long; Ma, Yu Shou; Zhu, Lei

2013-10-01

Understanding the complex effects of biotic and abiotic factors on the composition of vegetation is very important for developing and implementing strategies for promoting sustainable grassland development. The vegetation-disturbance-environment relationship was examined in degraded alpine grasslands in the headwater areas of three rivers on the Qinghai-Tibet Plateau in this study. The investigated hypotheses were that (1) the heterogeneity of the vegetation of the alpine grassland is due to a combination of biotic and abiotic factors and that (2) at a small scale, biotic factors are more important for the distribution of alpine vegetation. On this basis, four transects were set along altitudinal gradients from 3,770 to 3,890 m on a sunny slope, and four parallel transects were set along altitudinal gradients on a shady slope in alpine grasslands in Guoluo Prefecture of Qinghai Province, China. It was found that biological disturbances were the major forces driving the spatial heterogeneity of the alpine grassland vegetation and abiotic factors were of secondary importance. Heavy grazing and intensive rat activity resulted in increases in unpalatable and poisonous weeds and decreased fine forages in the form of sedges, forbs, and grasses in the vegetation composition. Habitat degradation associated with biological disturbances significantly affected the spatial variation of the alpine grassland vegetation, i.e., more pioneer plants of poisonous or unpalatable weed species, such as Ligularia virgaurea and Euphorbia fischeriana, were found in bare patches. Environmental/abiotic factors were less important than biological disturbances in affecting the spatial distribution of the alpine grassland vegetation at a small scale. It was concluded that rat control and light grazing should be applied first in implementing restoration strategies. The primary vegetation in lightly grazed and less rat-damaged sites should be regarded as a reference for devising vegetation restoration measures in alpine pastoral regions.

Drivers of spatial heterogeneity in nitrogen processing among three alpine plant communities in the Rocky Mountains

NASA Astrophysics Data System (ADS)

Churchill, A. C.; Beers, A.; Grinath, J.; Bowman, W. D.

2017-12-01

Nitrogen cycling across the globe has been fundamentally altered due to regional elevated N deposition and there is a cascade of ecosystem consequences including shifts in species composition, eutrophication, and soil acidification. Making predictions that encompass the factors that drive these ecosystem changes has frequently been limited to single ecosystem types, or areas with fairly homogenous abiotic conditions. The alpine is an ecosystem type that exhibits changes under relatively low levels of N depositions due to short growing seasons and shallow soils limiting N storage. While recent work provided estimates for the magnitude of N associated with ecosystem changes, less is known about the within-site factors that may interact to stabilize or amplify the differential response of N pools under future conditions of resource deposition. To examine numerous potential within-site and regional factors (both biotic and abiotic) affecting ecosystem N pools we examined the relationship between those factors and a suite of ecosystem pools of N followed by model selection procedures and structural equation modelling. Measurements were conducted at Niwot Ridge Long Term Ecological Research site and in Rocky Mountain National Park in three distinct alpine meadow ecosystems (dry, moist, and wet meadows). These meadows span a moisture gradient as well as plant community composition, thereby providing high variability of potential biotic and abiotic drivers across small spatial scales in the alpine. In general, regional scale abiotic factors such as site levels of annual average N deposition or precipitation were poor predictors of seasonal pools of N, while spring soil water pools of N were negatively correlated with elevation. Models containing multiple abiotic and biotic drivers, however, were best at predicting soil and plant pools of N across the two sites. Future analysis will include highlight interactions among with-site factors affecting N pools in the alpine using structural equation modelling to statistically examine the bidirectional relationship between plant communities and soil pools of N.

Investigations On Limestone Weathering Of El-Tuba Minaret El Mehalla, Egypt: A Case Study.

NASA Astrophysics Data System (ADS)

El-Gohary; A, M.

The weathering phenomena that have affected El-TUBA Minaret, one of the most important Islamic stone minarets in middle delta in Egypt; that has suffered from several factors of deterioration due to weathering phenomenon. The present investigations concern the weathering factors that may have affected the minaret via the following methods and techniques: a) Contact-free methods used to study the chemical and mineralogical composition of building materials before and after weathering effects such as SEM-EDX and XRD, b) Non-destructive methods to find out percentage of range of decay which has affected these materials as well as the deteriorating roles of the surrounding environment. This method has been used to make an anatomical scheme of these features especially to specific deteriorated parts by GIS and other digital imaging techniques. All results confirm that the degradation factors affecting the minaret building materials are essentially attributed to direct effects of weathering phenomena. These weathering phenomena arise from physical and chemical mechanisms which have lead to many deterioration forms on the following two scales: a) Macro scale of weathering phenomena (e.g. structural damages, crakes, loss of plumb and walls bulging), b) Micro scale of weathering phenomena (e.g. hydrated salts, bursting, flaking, coloration, scaling, skinning, exfoliation and soiling). Discussion on the management and rehabilitation of this monument is made, since it is one of the religious shrines in Egypt.

Genomics of lactation: role of nutrigenomics and nutrigenetics in the fatty acid composition of human milk.

PubMed

Sosa-Castillo, Elizabeth; Rodríguez-Cruz, Maricela; Moltó-Puigmartí, Carolina

2017-08-01

Human milk covers the infant's nutrient requirements during the first 6 months of life. The composition of human milk progressively changes during lactation and it is influenced by maternal nutritional factors. Nowadays, it is well known that nutrients have the ability to interact with genes and modulate molecular mechanisms impacting physiological functions. This has led to a growing interest among researchers in exploring nutrition at a molecular level and to the development of two fields of study: nutrigenomics, which evaluates the influence of nutrients on gene expression, and nutrigenetics, which evaluates the heterogeneous individual response to nutrients due to genetic variation. Fatty acids are one of the nutrients most studied in relation to lactation given their biologically important roles during early postnatal life. Fatty acids modulate transcription factors involved in the regulation of lipid metabolism, which in turn causes a variation in the proportion of lipids in milk. This review focuses on understanding, on the one hand, the gene transcription mechanisms activated by maternal dietary fatty acids and, on the other hand, the interaction between dietary fatty acids and genetic variation in genes involved in lipid metabolism. Both of these mechanisms affect the fatty acid composition of human milk.

On factors structuring the flatfish assemblage in the southern North Sea

NASA Astrophysics Data System (ADS)

Piet, G. J.; Pfisterer, A. B.; Rijnsdorp, A. D.

1998-09-01

Ten species of flatfish were studied to see to what extent interspecific competition influences their diet or spatial distribution and whether the potential of these flatfish species to avoid interspecific competition through resource partitioning is constrained by specific morphological characteristics. For this, seven morphological characteristics were measured, diet composition was determined from gut content analyses and overlap in distribution was determined from the co-occurrence in trawl hauls. Canonical correspondence analysis revealed the morphological characteristics that were most strongly correlated with the diet composition. Based on these findings the mouth gape was considered to be the most important morphological constraint affecting the choice of food. Two resource dimensions were distinguished along which interspecific competition can act on the flatfish assemblage: the trophic dimension (diet composition) and the spatial dimension (distribution). Resource partitioning was observed along both dimensions separately and, more importantly, the degree of resource partitioning along the two dimensions was negatively correlated. Especially the latter was considered strong circumstantial evidence that interspecific competition is a major factor structuring the flatfish assemblage. Resource partitioning along the two resource dimensions increased with decreasing mouth gape, suggesting that interspecific competition mainly acts on the small-mouthed fish, i.e. juveniles.

Long-term record of Argentine ant invasions reveals enduring ecological impacts.

PubMed

Menke, Sean B; Ward, Philip S; Holway, David A

2018-05-01

The ecological effects of species introductions can change in magnitude over time, but an understanding of how and why they do so remains incompletely understood. Clarifying this issue requires consideration of how temporal variation in invader traits affects invasion impacts (e.g., through differential effects on the diversity and composition of native species assemblages). We examine the temporal dynamics of Argentine ant invasions in northern California by resurveying 202 sites first sampled 30-40 yr ago. To test how invasion impacts change over time, we estimated native ant richness and species composition at 20 riparian woodland sites that span a 30-yr invasion chronosequence. We then use these data to test how variation in two invader traits (aggression and relative abundance) is related to time since invasion and invasion impact. Native ant assemblages along the chronosequence exhibited reduced native ant richness and altered species composition (compared to uninvaded control sites), but the magnitude of these impacts was independent of time since invasion. These results are corroborated by additional temporal comparisons of native ant assemblages at riparian sites sampled 20-30 yr ago. Our findings together illustrate that the impacts of invasions can persist undiminished over at least a 30-yr time frame and remain evident at regional scales. Although neither invader trait varied with time since invasion, native ant richness declined as the relative abundance of the Argentine ant increased. This latter result supports the hypothesis that factors reducing invader abundance at particular sites can decrease invasion impacts, but also that such changes may be due to site-specific factors (e.g., abiotic conditions) that affect invader abundance rather than time since invasion per se. Future studies should attempt to differentiate factors that are intrinsic to the process of invasion (e.g., changes in invader populations) from long-term environmental changes (e.g., climate change) that represent extrinsic influences on the dynamics of invasion. © 2018 by the Ecological Society of America.

Hydrothermal pretreatment of palm oil empty fruit bunch

NASA Astrophysics Data System (ADS)

Simanungkalit, Sabar Pangihutan; Mansur, Dieni; Nurhakim, Boby; Agustin, Astrid; Rinaldi, Nino; Muryanto, Fitriady, Muhammad Ariffudin

2017-01-01

Hydrothermal pretreatment methods in 2nd generation bioethanol production more profitable to be developed, since the conventional pretreatment, by using acids or alkalis, is associated with the serious economic and environmental constraints. The current studies investigate hydrothermal pretreatment of palm oil empty fruit bunch (EFB) in a batch tube reactor system with temperature and time range from 160 to 240 C and 15 to 30 min, respectively. The EFB were grinded and separated into 3 different particles sizes i.e. 10 mesh, 18 mesh and 40 mesh, prior to hydrothermal pretreatment. Solid yield and pH of the treated EFB slurries changed over treatment severities. The chemical composition of EFB was greatly affected by the hydrothermal pretreatment especially hemicellulose which decreased at higher severity factor as determined by HPLC. Both partial removal of hemicellulose and migration of lignin during hydrothermal pretreatment caused negatively affect for enzymatic hydrolysis. This studies provided important factors for maximizing hydrothermal pretreatment of EFB.

Relevant principal factors affecting the reproducibility of insect primary culture.

PubMed

Ogata, Norichika; Iwabuchi, Kikuo

2017-06-01

The primary culture of insect cells often suffers from problems with poor reproducibility in the quality of the final cell preparations. The cellular composition of the explants (cell number and cell types), surgical methods (surgical duration and surgical isolation), and physiological and genetic differences between donors may be critical factors affecting the reproducibility of culture. However, little is known about where biological variation (interindividual differences between donors) ends and technical variation (variance in replication of culture conditions) begins. In this study, we cultured larval fat bodies from the Japanese rhinoceros beetle, Allomyrina dichotoma, and evaluated, using linear mixed models, the effect of interindividual variation between donors on the reproducibility of the culture. We also performed transcriptome analysis of the hemocyte-like cells mainly seen in the cultures using RNA sequencing and ultrastructural analyses of hemocytes using a transmission electron microscope, revealing that the cultured cells have many characteristics of insect hemocytes.

Dietary and microbiome factors determine longevity in Caenorhabditis elegans

PubMed Central

Sánchez-Blanco, Adolfo; Rodríguez-Matellán, Alberto; González-Paramás, Ana; González-Manzano, Susana; Kim, Stuart K.; Mollinedo, Faustino

2016-01-01

Diet composition affects organismal health. Nutrient uptake depends on the microbiome. Caenorhabditis elegans fed a Bacillus subtilis diet live longer than those fed the standard Escherichia coli diet. Here we report that this longevity difference is primarily caused by dietary coQ, an antioxidant synthesized by E. coli but not by B. subtilis. CoQ-supplemented E. coli fed worms have a lower oxidation state yet live shorter than coQ-less B. subtilis fed worms. We showed that mutations affecting longevity for E. coli fed worms do not always lead to similar effects when worms are fed B. subtilis. We propose that coQ supplementation by the E. coli diet alters the worm cellular REDOX homeostasis, thus decreasing longevity. Our results highlight the importance of microbiome factors in longevity, argue that antioxidant supplementation can be detrimental, and suggest that the C. elegans standard E. coli diet can alter the effect of signaling pathways on longevity. PMID:27510225

Statistical Analysis of Factors Affecting Child Mortality in Pakistan.

PubMed

Ahmed, Zoya; Kamal, Asifa; Kamal, Asma

2016-06-01

Child mortality is a composite indicator reflecting economic, social, environmental, healthcare services, and their delivery situation in a country. Globally, Pakistan has the third highest burden of fetal, maternal, and child mortality. Factors affecting child mortality in Pakistan are investigated by using Binary Logistic Regression Analysis. Region, education of mother, birth order, preceding birth interval (the period between the previous child birth and the index child birth), size of child at birth, and breastfeeding and family size were found to be significantly important with child mortality in Pakistan. Child mortality decreased as level of mother's education, preceding birth interval, size of child at birth, and family size increased. Child mortality was found to be significantly higher in Balochistan as compared to other regions. Child mortality was low for low birth orders. Child survival was significantly higher for children who were breastfed as compared to those who were not.

Protein stability: a crystallographer’s perspective

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deller, Marc C., E-mail: mdeller@stanford.edu; Kong, Leopold; Rupp, Bernhard

An understanding of protein stability is essential for optimizing the expression, purification and crystallization of proteins. In this review, discussion will focus on factors affecting protein stability on a somewhat practical level, particularly from the view of a protein crystallographer. Protein stability is a topic of major interest for the biotechnology, pharmaceutical and food industries, in addition to being a daily consideration for academic researchers studying proteins. An understanding of protein stability is essential for optimizing the expression, purification, formulation, storage and structural studies of proteins. In this review, discussion will focus on factors affecting protein stability, on a somewhatmore » practical level, particularly from the view of a protein crystallographer. The differences between protein conformational stability and protein compositional stability will be discussed, along with a brief introduction to key methods useful for analyzing protein stability. Finally, tactics for addressing protein-stability issues during protein expression, purification and crystallization will be discussed.« less

A New Approach for Quantitative Evaluation of Ultrasonic Wave Attenuation in Composites

NASA Astrophysics Data System (ADS)

Ni, Qing-Qing; Li, Ran; Xia, Hong

2017-02-01

When ultrasonic waves propagate in composite materials, the propagation behaviors result from the combination effects of various factors, such as material anisotropy and viscoelastic property, internal microstructure and defects, incident wave characteristics and interface condition between composite components. It is essential to make it clear how these factors affect the ultrasonic wave propagation and attenuation characteristics, and how they mutually interact on each other. In the present paper, based on a newly developed time-domain finite element analysis code, PZflex, a unique approach for clarifying the detailed influence mechanism of aforementioned factors is proposed, in which each attenuation component can be extracted from the overall attenuation and analyzed respectively. By taking into consideration the interrelation between each individual attenuation component, the variation behaviors of each component and internal dynamic stress distribution against material anisotropy and matrix viscosity are separately and quantitatively evaluated. From the detailed analysis results of each attenuation component, the energy dissipation at interface is a major component in ultrasonic wave attenuation characteristics, which can provide a maximum contribution rate of 68.2 % to the overall attenuation, and each attenuation component is closely related to the material anisotropy and viscoelasticity. The results clarify the correlation between ultrasonic wave propagation characteristics and material viscoelastic properties, which will be useful in the further development of ultrasonic technology in defect detection.

The assemblage composition and structure of swimming crabs (Portunoidea) in continental shelf waters of southeastern Brazil

NASA Astrophysics Data System (ADS)

Andrade, L. S.; Frameschi, I. F.; Costa, R. C.; Castilho, A. L.; Fransozo, A.

2015-02-01

Three regions along the Brazilian coast characterized by the occurrence of contrasting natural phenomena, such as upwellings and continental input, were surveyed to determine the composition and structure of the assemblage of swimming crabs. Twelve monthly collections were undertaken (July 2010 to June 2011) in Macaé, Rio de Janeiro (MAC); Ubatuba, São Paulo (UBA); and São Francisco do Sul, Santa Catarina (SFS). The lowest values ​​of the phi sediment grain size measure, bottom temperature and the highest values of organic matter and salinity were measured in MAC. In all, 10,686 individuals were collected, belonging to six species of Portunoidea: Arenaeus cribrarius, Callinectes danae, Callinectes ornatus, Callinectes sapidus, Achelous spinicarpus and Achelous spinimanus. A Multiple Response Permutation Procedure (MRPP) test indicated that the species composition differed significantly among the sampling sites, showing substantial heterogeneity in the composition and abundance of species among regions. The results suggest that C. danae was more abundant in waters with lower salinity and lower organic matter content. In contrast, A. spinimanus is positively correlated with these factors, showing a greater abundance under the opposite conditions. Callinectes ornatus appeared not to show strong selectivity for particular habitat characteristics. We conclude from these findings that areas affected by different phenomena produce changes in the composition and abundance of the assemblage of Portunoidea. Although the strength of eutrophication differs between UBA and MAC, the substantial continental inflow affecting SFS favors the development of species that complete their life cycle in the estuary.

Mosquito vector-associated microbiota: Metabarcoding bacteria and eukaryotic symbionts across habitat types in Thailand endemic for dengue and other arthropod-borne diseases.

PubMed

Thongsripong, Panpim; Chandler, James Angus; Green, Amy B; Kittayapong, Pattamaporn; Wilcox, Bruce A; Kapan, Durrell D; Bennett, Shannon N

2018-01-01

Vector-borne diseases are a major health burden, yet factors affecting their spread are only partially understood. For example, microbial symbionts can impact mosquito reproduction, survival, and vectorial capacity, and hence affect disease transmission. Nonetheless, current knowledge of mosquito-associated microbial communities is limited. To characterize the bacterial and eukaryotic microbial communities of multiple vector species collected from different habitat types in disease endemic areas, we employed next-generation 454 pyrosequencing of 16S and 18S rRNA amplicon libraries, also known as metabarcoding. We investigated pooled whole adult mosquitoes of three medically important vectors, Aedes aegypti , Ae. albopictus , and Culex quinquefasciatus, collected from different habitats across central Thailand where we previously characterized mosquito diversity. Our results indicate that diversity within the mosquito microbiota is low, with the majority of microbes assigned to one or a few taxa. Two of the most common eukaryotic and bacterial genera recovered ( Ascogregarina and Wolbachia, respectively) are known mosquito endosymbionts with potentially parasitic and long evolutionary relationships with their hosts. Patterns of microbial composition and diversity appeared to differ by both vector species and habitat for a given species, although high variability between samples suggests a strong stochastic element to microbiota assembly. In general, our findings suggest that multiple factors, such as habitat condition and mosquito species identity, may influence overall microbial community composition, and thus provide a basis for further investigations into the interactions between vectors, their microbial communities, and human-impacted landscapes that may ultimately affect vector-borne disease risk.

Degradation, fatigue and failure of resin dental composite materials

PubMed Central

Drummond, James L.

2008-01-01

The intent of this article is to review the numerous factors that affect the mechanical properties of particle or fiber filler containing, indirect dental resin composite materials. The focus will be on degradation due to aging in different media, mainly water and water and ethanol, cyclic loading, and mixed mode loading on the flexure strength and fracture toughness. Next several selected papers will be examined in detail with respect to mixed and cyclic loading and then an examination of 3D tomography using multiaxial compression specimens. The main cause of failure, for most dental resin composites, is the breakdown of the resin matrix and or the interface between the filler and the resin matrix. In clinical studies, it appears that failure in the first 5 years is a restoration issue (technique or material selection) and after that time period from secondary decay. PMID:18650540

Degradation, Fatigue, and Failure of Resin Dental Composite Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drummond, J.L.

The intent of this article is to review the numerous factors that affect the mechanical properties of particle- or fiber-filler-containing indirect dental resin composite materials. The focus will be on the effects of degradation due to aging in different media, mainly water and water and ethanol, cyclic loading, and mixed-mode loading on flexure strength and fracture toughness. Several selected papers will be examined in detail with respect to mixed and cyclic loading, and 3D tomography with multi-axial compression specimens. The main cause of failure, for most dental resin composites, is the breakdown of the resin matrix and/or the interface betweenmore » the filler and the resin matrix. In clinical studies, it appears that failure in the first 5 years is a restoration issue (technique or material selection); after that time period, failure most often results from secondary decay.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Weizhao; Zhang, Zixuan; Lu, Jie

Carbon fiber composites have received growing attention because of their high performance. One economic method to manufacturing the composite parts is the sequence of forming followed by the compression molding process. In this sequence, the preforming procedure forms the prepreg, which is the composite with the uncured resin, to the product geometry while the molding process cures the resin. Slip between different prepreg layers is observed in the preforming step and this paper reports a method to characterize the properties of the interaction between different prepreg layers, which is critical to predictive modeling and design optimization. An experimental setup wasmore » established to evaluate the interactions at various industrial production conditions. The experimental results were analyzed for an in-depth understanding about how the temperature, the relative sliding speed, and the fiber orientation affect the tangential interaction between two prepreg layers. The interaction factors measured from these experiments will be implemented in the computational preforming program.« less

A dynamical model for describing behavioural interventions for weight loss and body composition change

PubMed Central

Navarro-Barrientos, J.-Emeterio; Rivera, Daniel E.; Collins, Linda M.

2011-01-01

We present a dynamical model incorporating both physiological and psychological factors that predicts changes in body mass and composition during the course of a behavioral intervention for weight loss. The model consists of a three-compartment energy balance integrated with a mechanistic psychological model inspired by the Theory of Planned Behavior (TPB). The latter describes how important variables in a behavioural intervention can influence healthy eating habits and increased physical activity over time. The novelty of the approach lies in representing the behavioural intervention as a dynamical system, and the integration of the psychological and energy balance models. Two simulation scenarios are presented that illustrate how the model can improve the understanding of how changes in intervention components and participant differences affect outcomes. Consequently, the model can be used to inform behavioural scientists in the design of optimised interventions for weight loss and body composition change. PMID:21673826

Numerically design the injection process parameters of parts fabricated with ramie fiber reinforced green composites

NASA Astrophysics Data System (ADS)

Chen, L. P.; He, L. P.; Chen, D. C.; Lu, G.; Li, W. J.; Yuan, J. M.

2017-01-01

The warpage deformation plays an important role on the performance of automobile interior components fabricated with natural fiber reinforced composites. The present work investigated the influence of process parameters on the warpage behavior of A pillar trim made of ramie fiber (RF) reinforced polypropylene (PP) composites (RF/PP) via numerical simulation with orthogonal experiment method and range analysis. The results indicated that fiber addition and packing pressure were the most important factors affecting warpage. The A pillar trim can achieved the minimum warpage value as of 2.124 mm under the optimum parameters. The optimal process parameters are: 70% percent of the default value of injection pressure for the packing pressure, 20 wt% for the fiber addition, 185 °C for the melt °C for the mold temperature, 7 s for the filling time and 17 s for the packing time.

Photocatalytic degradation of organic dyes using composite nanofibers under UV irradiation

NASA Astrophysics Data System (ADS)

Salama, Ahmed; Mohamed, Alaa; Aboamera, Nada M.; Osman, T. A.; Khattab, A.

2018-02-01

In this work, photocatalytic degradation of organic dyes such as methylene blue (MB) and indigo carmine (IC) have been studied by composite nanofibers systems containing cellulose acetate (CA), multiwall carbon nanotubes (CNT) and TiO2 nanoparticles under UV light. The amino factionalized TiO2-NH2 NPs cross-linked to the CA/CNT composite nanofibers works as a semiconductor catalyst. The morphology and crystallinity were characterized by scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction, and Fourier transform infrared spectroscopy. It was also seen that many factors affected the photodegradation rate, mainly the pH of the solution and the dye concentration, temperature, etc. The study demonstrated that IC degrades at a higher rate than MB. The maximum photodegradation rate of both organic dyes was achieved at a pH 2. In comparison to other studies, this work achieved high photodegradation rate in lower time and using less power intensity.

Factors affecting the formation of eutectic solid dispersions and their dissolution behavior.

PubMed

Vippagunta, Sudha R; Wang, Zeren; Hornung, Stefanie; Krill, Steven L

2007-02-01

The objective of this work was to obtain a fundamental understanding of the factors, specifically the properties of poorly water-soluble drugs and water-soluble carriers, which influence predominantly, the formation of eutectic or monotectic crystalline solid dispersion and their dissolution behavior. A theoretical model was applied on five poorly water-soluble drugs (fenofibrate, flurbiprofen, griseofulvin, naproxen, and ibuprofen) having diverse physicochemical properties and water-soluble carrier (polyethylene glycol (PEG) 8000) for the evaluation of these factors. Of these, two drugs, fenofibrate and flurbiprofen, and PEG of different molecular weights (3350, 8000, and 20000), were chosen as model drugs and carriers for further investigation. Experimental phase diagrams were constructed and dissolution testing was performed to assess the performance of the systems. The theoretical model predicted the formation of eutectic or monotectic solid dispersions of fenofibrate, griseofulvin, ibuprofen, and naproxen with PEG, holding the contribution of specific intermolecular interactions between compound and carrier to zero. In the case of the flurbiprofen-PEG eutectic system, intermolecular interactions between drug and polymer needed to be taken into consideration to predict the experimental phase diagram. The results of the current work suggest that the thermodynamic function of melting point and heat of fusion (as a measure of crystal energy of drug) plays a significant role in the formation of a eutectic system. Lipophilicity of the compound (as represented by cLog P) was also demonstrated to have an effect. Specific interactions between drug and carrier play a significant role in influencing the eutectic composition. Molar volume of the drug did not seem to have an impact on eutectic formation. The polymer molecular weight appeared to have an impact on the eutectic composition for flurbiprofen, which exhibits specific interactions with PEG, whereas no such impact of polymer molecular weight on eutectic composition was observed for fenofibrate, which does not exhibit specific interactions with PEG. The impact of polymer molecular weight on dissolution of systems where specific drug-polymer interactions are exhibited was also observed. The current work provides valuable insight into factors affecting formation and dissolution of eutectic systems, which can facilitate the rational selection of suitable water-soluble carriers. Copyright (c) 2006 Wiley-Liss, Inc.

Experimental design methods for bioengineering applications.

PubMed

Keskin Gündoğdu, Tuğba; Deniz, İrem; Çalışkan, Gülizar; Şahin, Erdem Sefa; Azbar, Nuri

2016-01-01

Experimental design is a form of process analysis in which certain factors are selected to obtain the desired responses of interest. It may also be used for the determination of the effects of various independent factors on a dependent factor. The bioengineering discipline includes many different areas of scientific interest, and each study area is affected and governed by many different factors. Briefly analyzing the important factors and selecting an experimental design for optimization are very effective tools for the design of any bioprocess under question. This review summarizes experimental design methods that can be used to investigate various factors relating to bioengineering processes. The experimental methods generally used in bioengineering are as follows: full factorial design, fractional factorial design, Plackett-Burman design, Taguchi design, Box-Behnken design and central composite design. These design methods are briefly introduced, and then the application of these design methods to study different bioengineering processes is analyzed.

Heterogeneous Landscapes on Steep Slopes at Low Altitudes as Hotspots of Bird Diversity in a Hilly Region of Nepal in the Central Himalayas.

PubMed

Basnet, Tej B; Rokaya, Maan B; Bhattarai, Bishnu P; Münzbergová, Zuzana

2016-01-01

Understanding factors determining the distribution of species is a key requirement for protecting diversity in a specific area. The aim of this study was to explore the factors affecting diversity and distribution of species of birds on different forested hills in central Nepal. The area is rich in species of birds. Because the area is characterized by steep gradients, we were also interested in the importance of altitude in determining the diversity and species composition of the bird communities. We assessed bird diversity and species composition based on point observations along a gradient of increasing altitude in two valleys (Kathmandu and Palung) in central Nepal. Data on environmental variables were also collected in order to identify the main determinants of bird diversity and species composition of the bird communities. We recorded 6522 individual birds belonging to 146 species, 77 genera and 23 families. Resident birds made up 80% (117 species) of the total dataset. The study supported the original expectation that altitude is a major determinant of species richness and composition of bird communities in the area. More diverse bird communities were found also in areas with steeper slopes. This together with the positive effect of greater heterogeneity suggests that forests on steep slopes intermixed with patches of open habitats on shallow soil at large spatial scales are more important for diverse bird communities than more disturbed habitats on shallow slopes. In addition, we demonstrated that while different habitat characteristics such as presence of forests edges and shrubs play an important role in driving species composition, but they do not affect species richness. This indicates that while habitat conditions are important determinants of the distribution of specific species, the number of niches is determined by large scale characteristics, such as landscape level habitat heterogeneity and altitude. Thus, to protect bird diversity in the mid-hills of central Nepal, we should maintain diverse local habitats (viz. forest, shrubs, open land, etc.) but also make sure the natural habitats on steeper slopes with large scale heterogeneity are maintained.

Heterogeneous Landscapes on Steep Slopes at Low Altitudes as Hotspots of Bird Diversity in a Hilly Region of Nepal in the Central Himalayas

PubMed Central

Basnet, Tej B.; Rokaya, Maan B.; Bhattarai, Bishnu P.; Münzbergová, Zuzana

2016-01-01

Understanding factors determining the distribution of species is a key requirement for protecting diversity in a specific area. The aim of this study was to explore the factors affecting diversity and distribution of species of birds on different forested hills in central Nepal. The area is rich in species of birds. Because the area is characterized by steep gradients, we were also interested in the importance of altitude in determining the diversity and species composition of the bird communities. We assessed bird diversity and species composition based on point observations along a gradient of increasing altitude in two valleys (Kathmandu and Palung) in central Nepal. Data on environmental variables were also collected in order to identify the main determinants of bird diversity and species composition of the bird communities. We recorded 6522 individual birds belonging to 146 species, 77 genera and 23 families. Resident birds made up 80% (117 species) of the total dataset. The study supported the original expectation that altitude is a major determinant of species richness and composition of bird communities in the area. More diverse bird communities were found also in areas with steeper slopes. This together with the positive effect of greater heterogeneity suggests that forests on steep slopes intermixed with patches of open habitats on shallow soil at large spatial scales are more important for diverse bird communities than more disturbed habitats on shallow slopes. In addition, we demonstrated that while different habitat characteristics such as presence of forests edges and shrubs play an important role in driving species composition, but they do not affect species richness. This indicates that while habitat conditions are important determinants of the distribution of specific species, the number of niches is determined by large scale characteristics, such as landscape level habitat heterogeneity and altitude. Thus, to protect bird diversity in the mid-hills of central Nepal, we should maintain diverse local habitats (viz. forest, shrubs, open land, etc.) but also make sure the natural habitats on steeper slopes with large scale heterogeneity are maintained. PMID:26938616

Bio-active glass air-abrasion has the potential to remove resin composite restorative material selectively

NASA Astrophysics Data System (ADS)

Milly, Hussam; Andiappan, Manoharan; Thompson, Ian; Banerjee, Avijit

2014-06-01

The aims of this study were to assess: (a) the chemistry, morphology and bioactivity of bio-active glass (BAG) air-abrasive powder, (b) the effect of three air-abrasion operating parameters: air pressure, powder flow rate (PFR) and the abrasive powder itself, on the selective removal of resin composite and (c) the required "time taken". BAG abrasive particles were characterised using scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). Standardised resin composite restorations created within an enamel analogue block (Macor™) in vitro, were removed using air-abrasion undersimulated clinical conditions. 90 standardised cavities were scanned before and after resin composite removal using laser profilometry and the volume of the resulting 3D images calculated. Multilevel linear model was used to identify the significant factors affecting Macor™ removal. BAG powder removed resin composite more selectively than conventional air-abrasion alumina powder using the same operating parameters (p < 0.001) and the effect of altering the unit's operating parameters was significant (p < 0.001). In conclusion, BAG powder is more efficient than alumina in the selective removal of resin composite particularly under specific operating parameters, and therefore may be recommended clinically as a method of preserving sound enamel structure when repairing and removing defective resin composite restorations.

A comparison of chemical compositions of reported altered oceanic crusts and global MORB data set: implication for isotopic heterogeneity of recycled materials

NASA Astrophysics Data System (ADS)

Shimoda, G.; Kogiso, T.

2017-12-01

Chemical composition of altered oceanic crust is one of important constraints to delineate chemical heterogeneity of the mantle. Accordingly, many researchers have been studied to determine bulk chemical composition of altered oceanic crust mainly based on chemical compositions of old oceanic crusts at Site 801 and Site 417/418, and young crust at Site 504 (e.g., Staudigel et al., 1996; Bach et al. 2003; Kuo et al., 2016). Their careful estimation provided reliable bulk chemical compositions of these Sites and revealed common geochemical feature of alteration. To assess effect of recycling of altered oceanic crust on chemical evolution of the mantle, it might be meaningful to discuss whether the reported chemical compositions of altered oceanic crusts can represent chemical composition of globally subducted oceanic crusts. Reported chemical compositions of fresh glass or less altered samples from Site 801, 417/418 and 504 were highly depleted compared to that of global MORB reported by Gale et al. (2013), suggesting that there might be sampling bias. Hence, it could be important to consider chemical difference between oceanic crusts of these three Sites and global MORB to discuss effect of recycling of oceanic crust on isotopic heterogeneity of the mantle. It has been suggested that one of controlling factors of chemical variation of oceanic crust is crustal spreading rate because different degree of partial melting affects chemical composition of magmas produced at a mid-ocean ridge. Crustal spreading rate could also affect intensity of alteration. Namely, oceanic crusts produced at slow-spreading ridges may prone to be altered due to existence of larger displacement faults compared to fast spreading ridges which have relatively smooth topography. Thus, it might be significant to evaluate isotopic evolution of oceanic crusts those were produced at different spreading rates. In this presentation, we will provide a possible chemical variation of altered oceanic crusts based on reported bulk chemical compositions of altered oceanic crusts and global data sets of MORB. On the basis of the chemical variation, we will discuss isotopic evolution of altered oceanic crusts to delineate isotopic variation of recycled oceanic crusts.

Interactive effects of multiple climate change factors on ammonia oxidizers and denitrifiers in a temperate steppe.

PubMed

Zhang, Cui-Jing; Shen, Ju-Pei; Sun, Yi-Fei; Wang, Jun-Tao; Zhang, Li-Mei; Yang, Zhong-Ling; Han, Hong-Yan; Wan, Shi-Qiang; He, Ji-Zheng

2017-04-01

Global climate change could have profound effects on belowground microbial communities and subsequently affect soil biogeochemical processes. The interactive effects of multiple co-occurring climate change factors on microbially mediated processes are not well understood. A four-factorial field experiment with elevated CO2, watering, nitrogen (N) addition and night warming was conducted in a temperate steppe of northern China. Real-time polymerase chain reaction and terminal-restriction fragment length polymorphism, combined with clone library techniques, were applied to examine the effects of those climate change factors on N-related microbial abundance and community composition. Only the abundance of ammonia-oxidizing bacteria significantly increased by nitrogen addition and decreased by watering. The interactions of watering × warming on the bacterial amoA community and warming × nitrogen addition on the nosZ community were found. Redundancy analysis indicated that the ammonia-oxidizing archaeal community was affected by total N and total carbon, while the community of bacterial amoA and nosZ were significantly affected by soil pH. According to a structural equation modeling analysis, climate change influenced net primary production indirectly by altering microbial abundance and activities. These results indicated that microbial responses to the combination of chronic global change tend to be smaller than expected from single-factor global change manipulations. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

How do cuticular hydrocarbons evolve? Physiological constraints and climatic and biotic selection pressures act on a complex functional trait

PubMed Central

Blaimer, Bonnie B.; Schmitt, Thomas

2017-01-01

Cuticular hydrocarbons (CHCs) cover the cuticles of virtually all insects, serving as a waterproofing agent and as a communication signal. The causes for the high CHC variation between species, and the factors influencing CHC profiles, are scarcely understood. Here, we compare CHC profiles of ant species from seven biogeographic regions, searching for physiological constraints and for climatic and biotic selection pressures. Molecule length constrained CHC composition: long-chain profiles contained fewer linear alkanes, but more hydrocarbons with disruptive features in the molecule. This is probably owing to selection on the physiology to build a semi-fluid cuticular layer, which is necessary for waterproofing and communication. CHC composition also depended on the precipitation in the ants' habitats. Species from wet climates had more alkenes and fewer dimethyl alkanes than those from drier habitats, which can be explained by different waterproofing capacities of these compounds. By contrast, temperature did not affect CHC composition. Mutualistically associated (parabiotic) species possessed profiles highly distinct from non-associated species. Our study is, to our knowledge, the first to show systematic impacts of physiological, climatic and biotic factors on quantitative CHC composition across a global, multi-species dataset. We demonstrate how they jointly shape CHC profiles, and advance our understanding of the evolution of this complex functional trait in insects. PMID:28298343

Fungal and Bacterial Communities in Indoor Dust Follow Different Environmental Determinants.

PubMed

Weikl, Fabian; Tischer, Christina; Probst, Alexander J; Heinrich, Joachim; Markevych, Iana; Jochner, Susanne; Pritsch, Karin

2016-01-01

People spend most of their time inside buildings and the indoor microbiome is a major part of our everyday environment. It affects humans' wellbeing and therefore its composition is important for use in inferring human health impacts. It is still not well understood how environmental conditions affect indoor microbial communities. Existing studies have mostly focussed on the local (e.g., building units) or continental scale and rarely on the regional scale, e.g. a specific metropolitan area. Therefore, we wanted to identify key environmental determinants for the house dust microbiome from an existing collection of spatially (area of Munich, Germany) and temporally (301 days) distributed samples and to determine changes in the community as a function of time. To that end, dust samples that had been collected once from the living room floors of 286 individual households, were profiled for fungal and bacterial community variation and diversity using microbial fingerprinting techniques. The profiles were tested for their association with occupant behaviour, building characteristics, outdoor pollution, vegetation, and urbanization. Our results showed that more environmental and particularly outdoor factors (vegetation, urbanization, airborne particulate matter) affected the community composition of indoor fungi than of bacteria. The passage of time affected fungi and, surprisingly, also strongly affected bacteria. We inferred that fungal communities in indoor dust changed semi-annually, whereas bacterial communities paralleled outdoor plant phenological periods. These differences in temporal dynamics cannot be fully explained and should be further investigated in future studies on indoor microbiomes.

Fungal and Bacterial Communities in Indoor Dust Follow Different Environmental Determinants

PubMed Central

Weikl, Fabian; Tischer, Christina; Probst, Alexander J.; Heinrich, Joachim; Markevych, Iana; Jochner, Susanne; Pritsch, Karin

2016-01-01

People spend most of their time inside buildings and the indoor microbiome is a major part of our everyday environment. It affects humans’ wellbeing and therefore its composition is important for use in inferring human health impacts. It is still not well understood how environmental conditions affect indoor microbial communities. Existing studies have mostly focussed on the local (e.g., building units) or continental scale and rarely on the regional scale, e.g. a specific metropolitan area. Therefore, we wanted to identify key environmental determinants for the house dust microbiome from an existing collection of spatially (area of Munich, Germany) and temporally (301 days) distributed samples and to determine changes in the community as a function of time. To that end, dust samples that had been collected once from the living room floors of 286 individual households, were profiled for fungal and bacterial community variation and diversity using microbial fingerprinting techniques. The profiles were tested for their association with occupant behaviour, building characteristics, outdoor pollution, vegetation, and urbanization. Our results showed that more environmental and particularly outdoor factors (vegetation, urbanization, airborne particulate matter) affected the community composition of indoor fungi than of bacteria. The passage of time affected fungi and, surprisingly, also strongly affected bacteria. We inferred that fungal communities in indoor dust changed semi-annually, whereas bacterial communities paralleled outdoor plant phenological periods. These differences in temporal dynamics cannot be fully explained and should be further investigated in future studies on indoor microbiomes. PMID:27100967

Evaluation of the Gratitude Questionnaire in a Chinese Sample of Adults: Factorial Validity, Criterion-Related Validity, and Measurement Invariance Across Sex

PubMed Central

Kong, Feng; You, Xuqun; Zhao, Jingjing

2017-01-01

The Gratitude Questionnaire (GQ; McCullough et al., 2002) is one of the most widely used instruments to assess dispositional gratitude. The purpose of this study was to validate a Chinese version of the GQ by examining internal consistency, factor structure, convergent validity, and measurement invariance across sex. A total of 1151 Chinese adults were recruited to complete the GQ, Positive Affect and Negative Affect Scales, and Satisfaction with Life Scale. Confirmatory factor analysis indicated that the original unidimensional model fitted well, which is in accordance with the findings in Western populations. Furthermore, the GQ had satisfactory composite reliability and criterion-related validity with measures of life satisfaction and affective well-being. Evidence of configural, metric and scalar invariance across sex was obtained. Tests of the latent mean differences found females had higher latent mean scores than males. These findings suggest that the Chinese version of GQ is a reliable and valid tool for measuring dispositional gratitude and can generally be utilized across sex in the Chinese context. PMID:28919873

Evaluation of the Gratitude Questionnaire in a Chinese Sample of Adults: Factorial Validity, Criterion-Related Validity, and Measurement Invariance Across Sex.

PubMed

Kong, Feng; You, Xuqun; Zhao, Jingjing

2017-01-01

The Gratitude Questionnaire (GQ; McCullough et al., 2002) is one of the most widely used instruments to assess dispositional gratitude. The purpose of this study was to validate a Chinese version of the GQ by examining internal consistency, factor structure, convergent validity, and measurement invariance across sex. A total of 1151 Chinese adults were recruited to complete the GQ, Positive Affect and Negative Affect Scales, and Satisfaction with Life Scale. Confirmatory factor analysis indicated that the original unidimensional model fitted well, which is in accordance with the findings in Western populations. Furthermore, the GQ had satisfactory composite reliability and criterion-related validity with measures of life satisfaction and affective well-being. Evidence of configural, metric and scalar invariance across sex was obtained. Tests of the latent mean differences found females had higher latent mean scores than males. These findings suggest that the Chinese version of GQ is a reliable and valid tool for measuring dispositional gratitude and can generally be utilized across sex in the Chinese context.

Deconvoluting effects of vine and soil properties on grape berry composition.

PubMed

Zerihun, Ayalsew; McClymont, Lexie; Lanyon, Dean; Goodwin, Ian; Gibberd, Mark

2015-01-01

Grape berry composition is influenced by several factors including grapevine and soil properties and their interactions. Understanding how these factors interact to determine berry composition is integral to producing berries with desired composition. Here we used extensive spatio-temporal data to identify significant vine and soil features that influence Shiraz berry composition. The concentrations of berry flavonoids (anthocyanins, tannin and total phenolics), total soluble solids and pH were typically negatively associated with canopy, crop and berry size factors whereas titratable acidity was positively associated. The strengths of the associations, however, were generally greater with the crop and berry size factors than with the canopy size factor. The analyses also resolved separate influences of berry and crop size on berry composition. Soil properties had significant influences on berry composition; however, when influences of soil factors on vine-attributes were accounted for, the apparent effects of soil factors on berry composition were largely non-existent. At each site, variations in berry composition were more strongly associated with crop and berry size than with canopy size factors. Apparent influences of soil properties on berry composition are indirect, being mediated via their effects on vine attributes (canopy, crop and berry sizes). © 2014 Society of Chemical Industry.

Effect of two doses of urea foliar application on leaves and grape nitrogen composition during two vintages.

PubMed

Pérez-Álvarez, Eva P; Garde-Cerdán, Teresa; García-Escudero, Enrique; Martínez-Vidaurre, José María

2017-06-01

Nitrogen affects grapevine growth and also yeast metabolism, which have a direct influence on fermentation kinetics and the formation of different volatile compounds. Throughout the grapevine cycle, soil nitrogen availability and grape nitrogen composition can vary because of different factors. Nitrogen foliar applications can contribute toward enhancing grapevine nitrogen status and minimize the problem of leaching that traditional nitrogen-soil applications can provoke. The present study aimed to evaluate the influence of urea foliar applications on grapevine nitrogen status and grape amino acid content. Accordingly, two different doses of urea were applied over the leaves of a 'Tempranillo' vineyard. The highest urea doses affected nitrogen content on blade leaf tissues after veraison. Must amino acid profiles were modified by urea application and some of the compounds increased their concentrations. The effect of year on the increase of must total amino acid concentrations was more important than the effect of the doses applied. Urea foliar applications can be an interesting tool for decreasing grapevine nitrogen deficiencies. This method of nitrogen implementation in the vineyard could avoid sluggish fermentation problems during winemaking, enhance must nitrogen composition, and contribute to improving wine quality. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Degradation of strength properties of epoxy resin filled with natural-based particles

NASA Astrophysics Data System (ADS)

Valášek, Petr; Habrová, Karolína; Müller, Miroslav

2018-05-01

Degradation of polymeric materials can be considered as a limiting factor for their use. Mechanical characteristics of epoxy resins are reduced, for example, by the action and changes of temperature or humidity. Degradation also occurs in composite systems where the epoxy resins function as matrices, i.e. in polymer composite materials. If a natural filler is used together with the epoxy resin, we refer to these materials as biocomposites, where also the natural character of the filler material greatly affects the degradation process. The paper focuses on the description of the shear strength of the resin filled with particles prepared from the seeds of dates of Phoenix Dactylifera plant. The degradation was evaluated experimentally in laboratory conditions via the climatic chamber. The experiment describes composites with a particle size of filler 100-200 μm with a concentration of 5 - 10 wt%. As the number of degradation cycles increased, the tensile strength of both the unfilled and the filled epoxy resin decreased. After 5 weeks, the drop was up to 50%. The presence of the particles did not significantly affect the shear strength compared to the non-filled resin. The described way of utilization of the natural-based particles is the possibility of material utilization of secondary natural materials.

Food waste and food processing waste for biohydrogen production: a review.

PubMed

Yasin, Nazlina Haiza Mohd; Mumtaz, Tabassum; Hassan, Mohd Ali; Abd Rahman, Nor'Aini

2013-11-30

Food waste and food processing wastes which are abundant in nature and rich in carbon content can be attractive renewable substrates for sustainable biohydrogen production due to wide economic prospects in industries. Many studies utilizing common food wastes such as dining hall or restaurant waste and wastes generated from food processing industries have shown good percentages of hydrogen in gas composition, production yield and rate. The carbon composition in food waste also plays a crucial role in determining high biohydrogen yield. Physicochemical factors such as pre-treatment to seed culture, pH, temperature (mesophilic/thermophilic) and etc. are also important to ensure the dominance of hydrogen-producing bacteria in dark fermentation. This review demonstrates the potential of food waste and food processing waste for biohydrogen production and provides a brief overview of several physicochemical factors that affect biohydrogen production in dark fermentation. The economic viability of biohydrogen production from food waste is also discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assessing the effects of abiotic stress and livestock grazing disturbance on an alpine grassland with CSR model

NASA Astrophysics Data System (ADS)

Wang, Jun; Luo, Peng; Mou, Chengxiang; Yang, Hao; Mo, Li; Luo, Chuan; Kattge, Jens

2016-04-01

How the abiotic factors represented by cold environment and biotic factors represented by livestock grazing will affect the vegetation structure of alpine grassland is a core issue in understanding the cause of biodiversity change on Tibetan Plateau. Past studies on changes of floristic composition, growth forms did not adequately answer question. Given the fact that the response of plant to environment change depend on its life strategy, a synthetical method that based on plant life strategy may deepen our understanding of the mechanism. Using Grime's concept of CSR plant classification, we carried out a vegetation survey along a gradient (three levels) of graze intensity on the south-east of Tibet Plateau, in order to evaluate the role and mechanism of abiotic stress and grazing disturbance in driving plant diversity change, by analyzing the plant life strategy compositions in each of the community and by comparing the characteristic of the strategy compositions along the graze gradient. When the graze intensity was relative low, the dominant plant life strategy gathered in the stress tolerance corner, which conformed the theory of environmental filter, indicating that the ideal top plant community may be dominated by the species with stress tolerant strategy. We also found that the response of strategy dominance to graze intensity increase is positively correlated with the competitive capacity (R 2=0.671; P<0.001) and negatively correlated with the capacity of tolerating stress (R 2=0.378; P=0.011), but is not affected by the ruderal strategy (R 2=0.047; P=0.42). This reflected a general shift of plant strategy from stress tolerant to competitive (rather than ruderal as expected) and suggested that the mechanism of graze to affect plant community is different from that of other disturbance like fire, clipping, till, etc. The particular selective foraging and escaping from feces may provide more opportunities for competitive than ruderal strategy to dominant the community. This study demonstrated that CSR plant strategy be a useful tool to evaluate the effects of abiotic and biotic factors on plant community assembly of alpine grassland, which may contribute to predict the impacts of climate change and human activity on alpine grassland plant diversity and ecosystem service function related.

Effect of prenatal programming on heifer development.

PubMed

Funston, Richard N; Summers, Adam F

2013-11-01

In beef cattle, the main factors influencing nutrient partitioning between the dam and fetus include age of the dam, number of fetuses, production demand, and environmental stress. These factors play a critical role in programming the fetus for its future environment and available resources. Fetal programming reportedly affects neonatal mortality and morbidity, postnatal growth rate, body composition, health, and reproduction. Two main mechanisms responsible for fetal programming include DNA methylation and histone modifications. Alterations in the genome can be passed through multiple generations. Maternal environment (nutrition, age, physiologic status) can program progeny heifer growth and reproductive performance. Copyright © 2013 Elsevier Inc. All rights reserved.

Effects of predation stress and food ration on perch gut microbiota.

PubMed

Zha, Yinghua; Eiler, Alexander; Johansson, Frank; Svanbäck, Richard

2018-02-06

Gut microbiota provide functions of importance to influence hosts' food digestion, metabolism, and protection against pathogens. Factors that affect the composition and functions of gut microbial communities are well studied in humans and other animals; however, we have limited knowledge of how natural food web factors such as stress from predators and food resource rations could affect hosts' gut microbiota and how it interacts with host sex. In this study, we designed a two-factorial experiment exposing perch (Perca fluviatilis) to a predator (pike, Esox lucius), and different food ratios, to examine the compositional and functional changes of perch gut microbiota based on 16S rRNA amplicon sequencing. We also investigated if those changes are host sex dependent. We showed that overall gut microbiota composition among individual perch significantly responded to food ration and predator presence. We found that species richness decreased with predator presence, and we identified 23 taxa from a diverse set of phyla that were over-represented when a predator was present. For example, Fusobacteria increased both at the lowest food ration and at predation stress conditions, suggesting that Fusobacteria are favored by stressful situations for the host. In concordance, both food ration and predation stress seemed to influence the metabolic repertoire of the gut microbiota, such as biosynthesis of other secondary metabolites, metabolism of cofactors, and vitamins. In addition, the identified interaction between food ration and sex emphasizes sex-specific responses to diet quantity in gut microbiota. Collectively, our findings emphasize an alternative state in gut microbiota with responses to changes in natural food webs depending on host sex. The obtained knowledge from this study provided us with an important perspective on gut microbiota in a food web context.

Mangrove habitat partitioning by Ucides cordatus (Ucididae): effects of the degree of tidal flooding and tree-species composition during its life cycle

NASA Astrophysics Data System (ADS)

Wunderlich, A. C.; Pinheiro, M. A. A.

2013-06-01

Environmental factors strongly affect mangrove crabs, and some factors modulate population structure and habitat partitioning during the crabs' life cycle. However, the effect of these environmental factors on habitat selection by mangrove crabs is still unknown. We evaluated habitat selection by the mangrove crab Ucides cordatus in mangrove forests with different degrees of predominance of Rhizophora mangle, Laguncularia racemosa or Avicennia schaueriana, two tidal flooding levels (less- and more-flooded), and two biological periods (breeding and non-breeding seasons). Sampling was conducted in four mangrove forests with different influences of these biotic and abiotic parameters. We used the data for sex ratio to explain environmental partitioning by this species. Females predominated in R. mangle mangroves, independently of the biological period (breeding or non-breeding seasons), and males predominated only in the less-flooded L. racemosa mangroves. The flooding level affected the sex ratio of U. cordatus, with a predominance of males in less-flooded mangroves, independently of the biological period; and a gender balance in the more-flooded mangroves only during the breeding season. Outside the breeding season, the largest specimens were recorded in the R. mangle mangroves, but in the breeding season, the largest crabs were recorded in the L. racemosa mangroves with a higher level of flooding. These results suggest that tree-species composition and tidal flooding level can have a significant effect on the habitat partitioning of sexes and sizes of the mangrove crab U. cordatus both during and outside the breeding season.

Relationship between the Decomposition Process of Coarse Woody Debris and Fungal Community Structure as Detected by High-Throughput Sequencing in a Deciduous Broad-Leaved Forest in Japan

PubMed Central

Yamashita, Satoshi; Masuya, Hayato; Abe, Shin; Masaki, Takashi; Okabe, Kimiko

2015-01-01

We examined the relationship between the community structure of wood-decaying fungi, detected by high-throughput sequencing, and the decomposition rate using 13 years of data from a forest dynamics plot. For molecular analysis and wood density measurements, drill dust samples were collected from logs and stumps of Fagus and Quercus in the plot. Regression using a negative exponential model between wood density and time since death revealed that the decomposition rate of Fagus was greater than that of Quercus. The residual between the expected value obtained from the regression curve and the observed wood density was used as a decomposition rate index. Principal component analysis showed that the fungal community compositions of both Fagus and Quercus changed with time since death. Principal component analysis axis scores were used as an index of fungal community composition. A structural equation model for each wood genus was used to assess the effect of fungal community structure traits on the decomposition rate and how the fungal community structure was determined by the traits of coarse woody debris. Results of the structural equation model suggested that the decomposition rate of Fagus was affected by two fungal community composition components: one that was affected by time since death and another that was not affected by the traits of coarse woody debris. In contrast, the decomposition rate of Quercus was not affected by coarse woody debris traits or fungal community structure. These findings suggest that, in the case of Fagus coarse woody debris, the fungal community structure is related to the decomposition process of its host substrate. Because fungal community structure is affected partly by the decay stage and wood density of its substrate, these factors influence each other. Further research on interactive effects is needed to improve our understanding of the relationship between fungal community structure and the woody debris decomposition process. PMID:26110605

Different mixing techniques in experimental mesocosms—does mixing affect plankton biomass and community composition?

PubMed Central

Striebel, Maren; Kirchmaier, Leo; Hingsamer, Peter

2014-01-01

Over the past four decades, mesocosm studies have been successfully used for a wide range of applications and have provided a lot of information on trophic interactions and biogeochemical cycling of aquatic ecosystem. However, the setup of such mesocosms (e.g., dimensions and duration of experiments) needs to be adapted to the relevant biological processes being investigated. Mixing of the water column is an important factor to be considered in mesocosm experiments because enclosing water in an artificial chamber always alters the mixing regime. Various approaches have been applied to generate mixing in experimental ecosystems, including pure mechanical mixing (e.g., using a disc), airlifts, bubbling with compressed air, and pumping. In this study, we tested different mixing techniques for outdoor mesocosms and their impact on plankton biomass and community composition. We compared mesocosms mixed with a disc, an airlift-system, and bubbling, and used a nonactively mixed mesocosm as a control. We investigated phytoplankton, ciliate, and zooplankton communities during a 19-d mesocosm experiment. Based on our results, we concluded that mechanical mixing with a disc was the most effective technique due to the undertow produced by lowering and lifting the disc. While no mixing technique affected seston biomass, zooplankton biomass was highest in the treatments mixed with the disc. The airlift treatments had the lowest relative share of small flagellates. However, no further differences in phytoplankton community composition occurred and no differences in zooplankton community composition existed between all actively mixed treatments. PMID:25729335

Permeability of boric acid across lipid bilayers and factors affecting it.

PubMed

Dordas, C; Brown, P H

2000-05-15

Boron enters plant roots as undissociated boric acid (H(3)BO(3)). Significant differences in B uptake are frequently observed even when plants are grown under identical conditions. It has been theorized that these differences reflect species differences in permeability coefficient of H(3)BO(3) across plasma membrane. The permeability coefficient of boric acid however, has not been experimentally determined across any artificial or plant membrane. In the experiments described here the permeability coefficient of boric acid in liposomes made of phosphatidylcholine was 4.9x10(-6) cm sec(-1), which is in good agreement with the theoretical value. The permeability coefficient varied from 7x10(-6) to 9.5x10(-9) cm sec(-1) with changes in sterols (cholesterol), the type of phospholipid head group, the length of the fatty acyl chain, and the pH of the medium. In this study we also used Arabidopsis thaliana mutants which differ in lipid composition to study the effect of lipid composition on B uptake. The chs1-1 mutant which has lower proportion of sterols shows 30% higher B uptake compared with the wild type, while the act1-1 mutant which has an increased percentage of longer fatty acids, exhibited 35% lower uptake than the wild type. Lipid composition changes in each of the remaining mutants influenced B uptake to various extents. These data suggest that lipid composition of the plasma membrane can affect total B uptake.

Shade tree spatial structure and pod production explain frosty pod rot intensity in cacao agroforests, Costa Rica.

PubMed

Gidoin, Cynthia; Avelino, Jacques; Deheuvels, Olivier; Cilas, Christian; Bieng, Marie Ange Ngo

2014-03-01

Vegetation composition and plant spatial structure affect disease intensity through resource and microclimatic variation effects. The aim of this study was to evaluate the independent effect and relative importance of host composition and plant spatial structure variables in explaining disease intensity at the plot scale. For that purpose, frosty pod rot intensity, a disease caused by Moniliophthora roreri on cacao pods, was monitored in 36 cacao agroforests in Costa Rica in order to assess the vegetation composition and spatial structure variables conducive to the disease. Hierarchical partitioning was used to identify the most causal factors. Firstly, pod production, cacao tree density and shade tree spatial structure had significant independent effects on disease intensity. In our case study, the amount of susceptible tissue was the most relevant host composition variable for explaining disease intensity by resource dilution. Indeed, cacao tree density probably affected disease intensity more by the creation of self-shading rather than by host dilution. Lastly, only regularly distributed forest trees, and not aggregated or randomly distributed forest trees, reduced disease intensity in comparison to plots with a low forest tree density. A regular spatial structure is probably crucial to the creation of moderate and uniform shade as recommended for frosty pod rot management. As pod production is an important service expected from these agroforests, shade tree spatial structure may be a lever for integrated management of frosty pod rot in cacao agroforests.

Unraveling the interactive effects of climate change and oil contamination on laboratory-simulated estuarine benthic communities.

PubMed

Coelho, Francisco J R C; Cleary, Daniel F R; Rocha, Rui J M; Calado, Ricardo; Castanheira, José M; Rocha, Sílvia M; Silva, Artur M S; Simões, Mário M Q; Oliveira, Vanessa; Lillebø, Ana I; Almeida, Adelaide; Cunha, Ângela; Lopes, Isabel; Ribeiro, Rui; Moreira-Santos, Matilde; Marques, Catarina R; Costa, Rodrigo; Pereira, Ruth; Gomes, Newton C M

2015-05-01

There is growing concern that modifications to the global environment such as ocean acidification and increased ultraviolet radiation may interact with anthropogenic pollutants to adversely affect the future marine environment. Despite this, little is known about the nature of the potential risks posed by such interactions. Here, we performed a multifactorial microcosm experiment to assess the impact of ocean acidification, ultraviolet B (UV-B) radiation and oil hydrocarbon contamination on sediment chemistry, the microbial community (composition and function) and biochemical marker response of selected indicator species. We found that increased ocean acidification and oil contamination in the absence of UV-B will significantly alter bacterial composition by, among other things, greatly reducing the relative abundance of Desulfobacterales, known to be important oil hydrocarbon degraders. Along with changes in bacterial composition, we identified concomitant shifts in the composition of oil hydrocarbons in the sediment and an increase in oxidative stress effects on our indicator species. Interestingly, our study identifies UV-B as a critical component in the interaction between these factors, as its presence alleviates harmful effects caused by the combination of reduced pH and oil pollution. The model system used here shows that the interactive effect of reduced pH and oil contamination can adversely affect the structure and functioning of sediment benthic communities, with the potential to exacerbate the toxicity of oil hydrocarbons in marine ecosystems. © 2014 John Wiley & Sons Ltd.

Impact of ethnicity, geography, and disease on the microbiota in health and inflammatory bowel disease.

PubMed

Prideaux, Lani; Kang, Seungha; Wagner, Josef; Buckley, Michael; Mahar, Jackie E; De Cruz, Peter; Wen, Zhonghui; Chen, Liping; Xia, Bing; van Langenberg, Daniel R; Lockett, Trevor; Ng, Siew C; Sung, Joseph J Y; Desmond, Paul; McSweeney, Chris; Morrison, Mark; Kirkwood, Carl D; Kamm, Michael A

2013-12-01

The gut microbiota is central to health and disorders such as inflammatory bowel disease. Differences in microbiota related to geography and ethnicity may hold the key to recent changes in the incidence of microbiota-related disorders. Gut mucosal microbiota was analyzed in 190 samples from 87 Caucasian and Chinese subjects, from Australia and Hong Kong, comprising 22 patients with Crohn's disease, 30 patients with ulcerative colitis, 29 healthy controls, and 6 healthy relatives of patients with Crohn's disease. Bacterial 16S rRNA microarray and 454 pyrosequencing were performed. The microbiota was diverse in health, regardless of ethnicity or geography (operational taxonomic unit number and Shannon diversity index). Ethnicity and geography, however, did affect microbial composition. Crohn's disease resulted in reduced bacterial diversity, regardless of ethnicity or geography, and was the strongest determinant of composition. In ulcerative colitis, diversity was reduced in Chinese subjects only, suggesting that ethnicity is a determinant of bacterial diversity, whereas composition was determined by disease and ethnicity. Specific phylotypes were different between health and disease. Chinese patients with inflammatory bowel disease more often than healthy Chinese tended to have had a Western diet in childhood, in the East and West. The healthy microbiota is diverse but compositionally affected by geographical and ethnic factors. The microbiota is substantially altered in inflammatory bowel disease, but ethnicity may also play an important role. This may be key to the changing epidemiology in developing countries, and emigrants to the West.

Factors Affecting Leaf Selection by Foregut-fermenting Proboscis Monkeys: New Insight from in vitro Digestibility and Toughness of Leaves

PubMed Central

Matsuda, Ikki; Clauss, Marcus; Tuuga, Augustine; Sugau, John; Hanya, Goro; Yumoto, Takakazu; Bernard, Henry; Hummel, Jürgen

2017-01-01

Free-living animals must make dietary choices in terms of chemical and physical properties, depending on their digestive physiology and availability of food resources. Here we comprehensively evaluated the dietary choices of proboscis monkeys (Nasalis larvatus) consuming young leaves. We analysed the data for leaf toughness and digestibility measured by an in vitro gas production method, in addition to previously reported data on nutrient composition. Leaf toughness, in general, negatively correlated with the crude protein content, one of the most important nutritional factors affecting food selection by leaf-eating primates. This result suggests that leaf toughness assessed by oral sensation might be a proximate cue for its protein content. We confirmed the importance of the leaf chemical properties in terms of preference shown by N. larvatus; leaves with high protein content and low neutral detergent fibre levels were preferred to those of the common plant species. We also found that these preferred leaves were less tough and more digestible than the alternatives. Our in vitro results also suggested that N. larvatus were little affected by secondary plant compounds. However, the spatial distribution pattern of plant species was the strongest factor explaining the selection of the preferred leaf species. PMID:28211530

Nonuniformity of the chemical composition of a capillary discharge plasma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kocharyan, A. E.; Bobrova, N. A.; Sasorov, P. V.

A steady-state distribution of the concentration of two ion species in a capillary discharge plasma is studied using MHD equations for a plasma with a spatially nonuniform, time-dependent chemical composition. In our case, the set of equations is significantly simplified because of the steady-state character and symmetry of the problem. Even with such simplification, however, some results could be obtained only by numerical integration. The factors affecting the distribution of heavy ions are studied. It is shown that the distribution of the heavy impurity over the discharge cross section can be much more nonuniform than the distribution of the mainmore » component (hydrogen). A simple criterion for such a nonuniformity is obtained.« less

The context of discrimination: workplace conditions, institutional environments, and sex and race discrimination charges.

PubMed

Hirsh, C Elizabeth; Kornrich, Sabino

2008-03-01

This article explores the organizational conditions under which discrimination charges occur. Drawing on structural and organizational theories of the workplace, the authors demonstrate how organizational conditions affect workers' and regulatory agents' understandings of unlawful discrimination. Using a national sample of work establishments, matched to discrimination-charge data obtained from the Equal Employment Opportunity Commission (EEOC), the authors examine how characteristics of the workplace and institutional environment affect variation in the incidence of workers' charges of sex and race discrimination and in the subset of discrimination claims that are verified by EEOC investigators. The findings indicate that workplace conditions, including size, composition, and minority management, affect workers' charges as well as verified claims; the latter are also affected by institutional factors, such as affirmative action requirements, subsidiary status, and industrial sector. These results suggest that internal workplace conditions affect both workers' and regulatory agents' interpretations of potentially discriminatory experiences, while institutional conditions matter only for regulatory agents' interpretations of those events.

Physico-Chemical Factors Affecting Hydrothermal Resistance and Bonding of Polymeric Composites to Steel Surfaces

DTIC Science & Technology

1985-11-01

and 1.0% PM-odified zinc phosphate hydrate crystals. -117- temperature of decomposition at -1750C, is associated with the dehydration of the...reactions between divalent Ca ions released from CaO-SIO2 grains and carboxylate anions "(COO) yielded during the hydrolysis of functional pendent carboxyl...deterioration of polymers, caused by the hydrolysis of a pendent carbcxyl group, can be restrained by ionic cross-linking initiated by the strongly

Curing mode affects bond strength of adhesively luted composite CAD/CAM restorations to dentin.

PubMed

Lührs, Anne-Katrin; Pongprueksa, Pong; De Munck, Jan; Geurtsen, Werner; Van Meerbeek, Bart

2014-03-01

To determine the effect of curing mode and restoration-surface pre-treatment on the micro-tensile bond strength (μTBS) to dentin. Sandblasted CAD/CAM composite blocks (LAVA Ultimate, 3M ESPE) were cemented to bur-cut dentin using either the etch & rinse composite cement Nexus 3 ('NX3', Kerr) with Optibond XTR ('XTR', Kerr), or the self-etch composite cement RelyX Ultimate ('RXU', 3M ESPE) with Scotchbond Universal ('SBU', 3M ESPE). All experimental groups included different 'curing modes' (light-curing of adhesive and cement ('LL'), light-curing of adhesive and auto-cure of cement ('LA'), co-cure of adhesive through light-curing of cement ('AL'), or complete auto-cure ('AA')) and different 'restoration-surface pre-treatments' of the composite block (NX3: either a silane primer (Kerr), or the XTR adhesive; RXU: either silane primer (RelyX Ceramic Primer, 3M ESPE) and SBU, or solely SBU). After water-storage (7 days, 37°C), the μTBS was measured. Additionally, the degree of conversion (DC) of both cements was measured after 10min and after 1 week, either auto-cured (21°C/37°C) or light-cured (directly/through 3-mm CAD/CAM composite). The linear mixed-effects model (α=0.05) revealed a significant influence of the factors 'curing mode' and 'composite cement', and a less significant effect of the factor 'restoration-surface pre-treatment'. Light-curing 'LL' revealed the highest μTBS, which decreased significantly for all other curing modes. For curing modes 'AA' and 'AL', the lowest μTBS and a high percentage of pre-testing failures were reported. Overall, DC increased with light-curing and incubation time. The curing mode is decisive for the bonding effectiveness of adhesively luted composite CAD/CAM restorations to dentin. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Psychometric evaluation of dietary self-efficacy and outcome expectation scales in female college freshmen.

PubMed

Kedem, Leia E; Evans, Ellen M; Chapman-Novakofski, Karen

2014-11-01

Lifestyle interventions commonly measure psychosocial beliefs as precursors to positive behavior change, but often overlook questionnaire validation. This can affect measurement accuracy if the survey has been developed for a different population, as differing behavioral influences may affect instrument validity. The present study aimed to explore psychometric properties of self-efficacy and outcome expectation scales-originally developed for younger children-in a population of female college freshmen (N = 268). Exploratory principal component analysis was used to investigate underlying data patterns and assess validity of previously published subscales. Composite scores for reliable subscales (Cronbach's α ≥ .70) were calculated to help characterize self-efficacy and outcome expectation beliefs in this population. The outcome expectation factor structure clearly comprised of positive (α = .81-.90) and negative outcomes (α = .63-.67). The self-efficacy factor structure included themes of motivation and effort (α = .75-.94), but items pertaining to hunger and availability cross-loaded often. Based on cross-loading patterns and low Cronbach's alpha values, respectively, self-efficacy items regarding barriers to healthy eating and negative outcome expectation items should be refined to improve reliability. Composite scores suggested that eating healthfully was associated with positive outcomes, but self-efficacy to do so was lower. Thus, dietary interventions for college students may be more successful by including skill-building activities to enhance self-efficacy and increase the likelihood of behavior change. © The Author(s) 2014.

Seasonal Changes in the Caste Distribution of Foraging Populations of Formosan Subterranean Termite in New Orleans, Louisiana.

PubMed

Cornelius, Mary L; Osbrink, Weste L A; Gallatin, Erin M

2015-01-01

This study examined the relationship between temperature, precipitation, soil composition, levels of feeding damage, and the caste distribution (workers, soldiers, nymphs) of the Formosan subterranean termite, Coptotermes formosanus Shiraki, collected in underground monitoring stations over a 12 mo period. Because nymphs are the caste that develops into alates, the seasonal abundance of nymphs was examined over a 5 yr period. Numbers of workers, soldiers, and soldier/worker ratio were significantly affected by month. Recruitment and retention of foraging termites in stations was significantly affected by the level of feeding damage. The number of nymphs collected in monitoring stations was highly variable. In the 12 mo test, there was a significant correlation between numbers of nymphs and level of feeding damage, temperature, precipitation, and soil composition. Over a 5 yr period, significantly more nymphs were collected in 2011 than in 2007 and 2008. Peak nymph collections varied from year to year. Overall, peak nymph collections were more likely to occur in Mar., Sept., and Oct. Increasing our knowledge of the environmental factors that influence recruitment and retention of foraging termites in monitoring stations could influence termite bait placement and improve baiting strategies for termite control. Identifying the key factors that cause aggregations of nymphs in underground stations could increase our ability to predict the intensity and location of alate swarms. © Crown copyright 2015.

Polymerization Stress Development in Dental Composites: Effect of Cavity Design Factor

PubMed Central

Antonucci, Joseph M.; Giuseppetti, Anthony A.; O’Donnell, Justin N.R.; Schumacher, Gary E.; Skrtic, Drago

2009-01-01

The objective of the study was to assess the effect of the cavity design factor (C-factor) on polymerization stress development (PSD) in resin composites. An experimental resin (BT resin) was prepared, which contained 2,2-bis[p-(2’-hydroxy-3’-methacryloxypropoxy)phenylene]propane (B) and triethylene glycol dimethacrylate (T) in 1:1 mass ratio, and an activator for visible light polymerization. An experimental composite with demonstrated remineralizing potential was also formulated by inclusion into the BT resin of zirconia-hybridized amorphous calcium phosphate (ACP) filler at a mass fraction of 40 % (BT/ACP composite). A commercial glass-filled composite (TPH) was used as a control. To assess the effect of the test geometry on PSD, C-factor was systematically varied between 0.8 and 6.0 by varying the height of the cylindrical composite specimens. The measured PSD values obtained by cantilever beam tensometry for specimens with variable C-factors were normalized for mass to specimens with a C-factor of 1.33 (h=2.25 mm) as controls to give calculated PSD values. Degrees of vinyl conversions (DC) attained in the TPH control and in the experimental BT/ACP composites were measured by near-infrared spectroscopy. In both the TPH and BT/ACP composite series, PSDcalc increased with the increasing C-factor, confirming the hypothesis that the C-factor value influences PSD values. The higher PSDmeas and PSDcalc values for the experimental BT/ACP composite compared to the commercial TPH composite probably reflect differences in the type and mass of the resin and filler phases in the two types of composite. These differences also account for the observed variation (21 %) in DC attained in a BT/ACP composite 2 h after cure (69.5 %) and in the DC of the TPH composite (57.5 %) having the same C-factor. The cavity design factor seems to play a key role in influencing the PSD of bonded composites, but other factors such as composite mass and composition also must be considered for their effects on PSD. PMID:26413236

Hypoxia-driven angiogenesis: role of tip cells and extracellular matrix scaffolding.

PubMed

Germain, Stéphane; Monnot, Catherine; Muller, Laurent; Eichmann, Anne

2010-05-01

Angiogenesis is a highly coordinated tissue remodeling process leading to blood vessel formation. Hypoxia triggers angiogenesis via induction of expression of growth factors such as vascular endothelial growth factor (VEGF). VEGF instructs endothelial cells to form tip cells, which lead outgrowing capillary sprouts, whereas Notch signaling inhibits sprout formation. Basement membrane deposition and mechanical cues from the extracellular matrix (ECM) induced by hypoxia may participate to coordinated vessel sprouting in conjunction with the VEGF and Notch signaling pathways. Hypoxia regulates ECM composition, deposition, posttranslational modifications and rearrangement. In particular, hypoxia-driven vascular remodeling is dynamically regulated through modulation of ECM-modifying enzyme activities that eventually affect both matricellular proteins and growth factor availability. Better understanding of the complex interplay between endothelial cells and soluble growth factors and mechanical factors from the ECM will certainly have significant implications for understanding the regulation of developmental and pathological angiogenesis driven by hypoxia.

Prediction of alpha factor values for fine pore aeration systems.

PubMed

Gillot, S; Héduit, A

2008-01-01

The objective of this work was to analyse the impact of different geometric and operating parameters on the alpha factor value for fine bubble aeration systems equipped with EPDM membrane diffusers. Measurements have been performed on nitrifying plants operating under extended aeration and treating mainly domestic wastewater. Measurements performed on 14 nitrifying plants showed that, for domestic wastewater treatment under very low F/M ratios, the alpha factor is comprised between 0.44 and 0.98. A new composite variable (the Equivalent Contact Time, ECT) has been defined and makes it possible for a given aeration tank, knowing the MCRT, the clean water oxygen transfer coefficient and the supplied air flow rate, to predict the alpha factor value. ECT combines the effect on mass transfer of all generally accepted factors affecting oxygen transfer performances (air flow rate, diffuser submergence, horizontal flow). (c) IWA Publishing 2008.

Dietary factors affecting susceptibility to urinary tract infection.

PubMed

Kontiokari, Tero; Nuutinen, Matti; Uhari, Matti

2004-04-01

Urinary tract infection (UTI) is usually an ascending infection caused by bacteria derived from stools. Since the bacterial composition of stools is dependent on the diet, it is likely that the risk of UTI will change with changes in the diet. Most data describing diet as a risk factor for UTI come from epidemiological and interventional trials. It has been shown in a case-control setting that frequent consumption of fresh berry or fruit juices and fermented milk products containing probiotic bacteria decreases the risk for UTI recurrence in women. Several interventional trials have found Vaccinium berry products to provide protection from UTI recurrence. Probiotics have not been able to prevent UTI in interventional trials. However, the lack of an effect may be related to too low a dose or to the use of non-optimal products in these trials. Limited data are available on the effects of nutrition on UTI in children. However, there is no reason to expect that children would be different from adults in this respect. In this review, we discuss the dietary factors affecting the susceptibility to UTI.

Factors affecting the use of contraception in Bangladesh: a multivariate analysis.

PubMed

Ullah, M S; Chakraborty, N

1993-09-01

The government of Bangladesh since independence has tried to strengthen the national family planning program. Using data from the 1989 Bangladesh Fertility Survey on a nationally representative sample of 7984 rural and urban households, the authors consider fifteen socioeconomic and demographic variables and assess their relative importance in relation to current contraceptive use. The data indicate that 31.1% of younger and lower parity women use contraceptives. Women's education, followed by women's participation in family planning decision making, were the most important of selected factors which positively affect current use of contraception. Administrative division, desire for additional children, urban residence, and family planning worker visits were also important factors significantly and positively related to the current use of contraception. Husband's occupation was strongly associated with contraceptive use. Child loss, however, was negatively associated with contraceptive use, followed by sex composition of living children. The authors suggest that women should be encouraged to participate in family decisions, and become informed about their rights, privileges, and family law. Finally, it was found that education makes less difference to contraceptive use where family planning programs are strong.

Reproduction and monogamy in captive flock of greater flamingos (Phoenicopterus Roseus).

PubMed

Sandri, Camillo; Sammarini, Carolina; Regaiolli, Barbara; Spiezio, Caterina; Piccirillo, Alessandra

2018-01-01

Due to the great number of greater flamingos in captivity and their long life span, studying their behavior and welfare might be useful to improve the husbandry and breeding of this species in zoos. This study aimed to investigate factors affecting the breeding activity of captive greater flamingos (Phoenicopterus roseus) from 2012 to 2016. To estimate reproductive success, the number of pairs, eggs laid, and hatchlings were recorded. In addition, information on age, egg-laying history of the partners, and pair composition was collected. An increase in the number of pairs, eggs, and hatchlings was reported over the years. For each breeding season, there were pairs who laid more than once, especially in 2014 and 2015. Approximately 50% of pairs were monogamous between consecutive years; however, the percentage dropped gradually when comparing nonconsecutive years. Senescence and previous experience seemed to affect the reproductive success of the study flamingos. In conclusion, different factors can influence the reproduction of greater flamingos in zoos. All these factors are related to nonhuman animal welfare and need to be considered in developing and improving management practices.

The affective dimension of pain as a risk factor for drug and alcohol addiction.

PubMed

LeBlanc, Dana M; McGinn, M Adrienne; Itoga, Christy A; Edwards, Scott

2015-12-01

Addiction, or substance use disorder (SUD), is a devastating psychiatric disease composed of multiple elemental features. As a biobehavioral disorder, escalation of drug and/or alcohol intake is both a cause and consequence of molecular neuroadaptations in central brain reinforcement circuitry. Multiple mesolimbic areas mediate a host of negative affective and motivational symptoms that appear to be central to the addiction process. Brain stress- and reinforcement-related regions such as the central amygdala (CeA), prefrontal cortex (PFC), and nucleus accumbens (NAc) also serve as central processors of ascending nociceptive input. We hypothesize that a sensitization of brain mechanisms underlying the processing of persistent and maladaptive pain contributes to a composite negative affective state to drive the enduring, relapsing nature of addiction, particularly in the case of alcohol and opioid use disorder. At the neurochemical level, pain activates central stress-related neuropeptide signaling, including the dynorphin and corticotropin-releasing factor (CRF) systems, and by this process may facilitate negative affect and escalated drug and alcohol use over time. Importantly, the widespread prevalence of unresolved pain and associated affective dysregulation in clinical populations highlights the need for more effective analgesic medications with reduced potential for tolerance and dependence. The burgeoning epidemic of prescription opioid abuse also demands a closer investigation into the neurobiological mechanisms of how pain treatment could potentially represent a significant risk factor for addiction in vulnerable populations. Finally, the continuing convergence of sensory and affective neuroscience fields is expected to generate insight into the critical balance between pain relief and addiction liability, as well as provide more effective therapeutic strategies for chronic pain and addiction. Copyright © 2015 Elsevier Inc. All rights reserved.

Genetic admixture, social-behavioural factors and body composition are associated with blood pressure differently by racial-ethnic group among children.

PubMed

Klimentidis, Y C; Dulin-Keita, A; Casazza, K; Willig, A L; Allison, D B; Fernandez, J R

2012-02-01

Cardiovascular disease has a progressively earlier age of onset, and disproportionately affects African Americans (AAs) in the United States. It has been difficult to establish the extent to which group differences are due to physiological, genetic, social or behavioural factors. In this study, we examined the association between blood pressure and these factors among a sample of 294 children, identified as AA, European American or Hispanic American. We use body composition, behavioural (diet and physical activity) and survey-based measures (socio-economic status and perceived racial discrimination), as well as genetic admixture based on 142 ancestry informative markers (AIMs) to examine associations with systolic and diastolic blood pressure. We find that associations differ by ethnic/racial group. Notably, among AAs, physical activity and perceived racial discrimination, but not African genetic admixture, are associated with blood pressure, while the association between blood pressure and body fat is nearly absent. We find an association between blood pressure and an AIM near a marker identified by a recent genome-wide association study. Our findings shed light on the differences in risk factors for elevated blood pressure among ethnic/racial groups, and the importance of including social and behavioural measures to grasp the full genetic/environmental aetiology of disparities in blood pressure.

Children's Computation of Complex Linguistic Forms: A Study of Frequency and Imageability Effects

PubMed Central

Dye, Cristina D.; Walenski, Matthew; Prado, Elizabeth L.; Mostofsky, Stewart; Ullman, Michael T.

2013-01-01

This study investigates the storage vs. composition of inflected forms in typically-developing children. Children aged 8–12 were tested on the production of regular and irregular past-tense forms. Storage (vs. composition) was examined by probing for past-tense frequency effects and imageability effects – both of which are diagnostic tests for storage – while controlling for a number of confounding factors. We also examined sex as a factor. Irregular inflected forms, which must depend on stored representations, always showed evidence of storage (frequency and/or imageability effects), not only across all children, but also separately in both sexes. In contrast, for regular forms, which could be either stored or composed, only girls showed evidence of storage. This pattern is similar to that found in previously-acquired adult data from the same task, with the notable exception that development affects which factors influence the storage of regulars in females: imageability plays a larger role in girls, and frequency in women. Overall, the results suggest that irregular inflected forms are always stored (in children and adults, and in both sexes), whereas regulars can be either composed or stored, with their storage a function of various item- and subject-level factors. PMID:24040318

Genetic admixture, social-behavioral factors, and body composition are associated with blood pressure differently by racial-ethnic group among children.

PubMed Central

Klimentidis, Yann C.; Dulin-Keita, Akilah; Casazza, Krista; Willig, Amanda L.; Allison, David B.; Fernandez, Jose R.

2011-01-01

Cardiovascular disease has a progressively earlier age of onset, and disproportionately affects African Americans in the US. It has been difficult to establish the extent to which group differences are due to physiological, genetic, social, or behavioral factors. In this study, we examined the association between blood pressure and these factors among a sample of 294 children, identified as African-, European-, or Hispanic-American. We use body composition, behavioral (diet and physical activity), and survey-based measures (socio-economic status and perceived racial discrimination), as well as genetic admixture based on 142 ancestry informative markers (AIM) to examine associations with systolic and diastolic blood pressure. We find that associations differ by ethnic/racial group. Notably, among African Americans, physical activity and perceived racial discrimination, but not African genetic admixture, are associated with blood pressure, while the association between blood pressure and body fat is nearly absent. We find an association between blood pressure and an AIM near a marker identified by a recent genome-wide association study. Our findings shed light on the differences in risk factors for elevated blood pressure among ethnic/racial groups, and the importance of including social and behavioral measures to grasp the full genetic/environmental etiology of disparities in blood pressure. PMID:21248781

Codiversification of gastrointestinal microbiota and phylogeny in passerines is not explained by ecological divergence.

PubMed

Kropáčková, Lucie; Těšický, Martin; Albrecht, Tomáš; Kubovčiak, Jan; Čížková, Dagmar; Tomášek, Oldřich; Martin, Jean-François; Bobek, Lukáš; Králová, Tereza; Procházka, Petr; Kreisinger, Jakub

2017-10-01

Vertebrate gut microbiota (GM) is comprised of a taxonomically diverse consortium of symbiotic and commensal microorganisms that have a pronounced effect on host physiology, immune system function and health status. Despite much research on interactions between hosts and their GM, the factors affecting inter- and intraspecific GM variation in wild populations are still poorly known. We analysed data on faecal microbiota composition in 51 passerine species (319 individuals) using Illumina MiSeq sequencing of bacterial 16S rRNA (V3-V4 variable region). Despite pronounced interindividual variation, GM composition exhibited significant differences at the interspecific level, accounting for approximately 20%-30% of total GM variation. We also observed a significant correlation between GM composition divergence and host's phylogenetic divergence, with strength of correlation higher than that of GM vs. ecological or life history traits and geographic variation. The effect of host's phylogeny on GM composition was significant, even after statistical control for these confounding factors. Hence, our data do not support codiversification of GM and passerine phylogeny solely as a by-product of their ecological divergence. Furthermore, our findings do not support that GM vs. host's phylogeny codiversification is driven primarily through trans-generational GM transfer as the GM vs. phylogeny correlation does not increase with higher sequence similarity used when delimiting operational taxonomic units. Instead, we hypothesize that the GM vs. phylogeny correlation may arise as a consequence of interspecific divergence of genes that directly or indirectly modulate composition of GM. © 2017 John Wiley & Sons Ltd.

Composite Overwrapped Pressure Vessels, A Primer

NASA Technical Reports Server (NTRS)

McLaughlan, Pat B.; Forth, Scott C.; Grimes-Ledesma, Lorie R.

2011-01-01

Due to the extensive amount of detailed information that has been published on composite overwrapped pressure vessels (COPVs), this document has been written to serve as a primer for those who desire an elementary knowledge of COPVs and the factors affecting composite safety. In this application, the word "composite" simply refers to a matrix of continuous fibers contained within a resin and wrapped over a pressure barrier to form a vessel for gas or liquid containment. COPVs are currently used at NASA to contain high pressure fluids in propulsion, science experiments, and life support applications. They have a significant weight advantage over all metal vessels but require unique design, manufacturing, and test requirements. COPVs also involve a much more complex mechanical understanding due to the interplay between the composite overwrap and the inner liner. A metallic liner is typically used in a COPV as a fluid permeation barrier. The liner design concepts and requirements have been borrowed from all-metal vessels. However, application of metallic vessel design standards to a very thin liner is not straightforward. Different failure modes exist for COPVs than for all-metal vessels, and understanding of these failure modes is at a much more rudimentary level than for metal vessels.

The influences of canopy species and topographic variables on understory species diversity and composition in coniferous forests.

PubMed

Huo, Hong; Feng, Qi; Su, Yong-hong

2014-01-01

Understanding the factors that influence the distribution of understory vegetation is important for biological conservation and forest management. We compared understory species composition by multi-response permutation procedure and indicator species analysis between plots dominated by Qinghai spruce (Picea crassifolia Kom.) and Qilian juniper (Sabina przewalskii Kom.) in coniferous forests of the Qilian Mountains, northwestern China. Understory species composition differed markedly between the forest types. Many heliophilous species were significantly associated with juniper forest, while only one species was indicative of spruce forest. Using constrained ordination and the variation partitioning model, we quantitatively assessed the relative effects of two sets of explanatory variables on understory species composition. The results showed that topographic variables had higher explanatory power than did site conditions for understory plant distributions. However, a large amount of the variation in understory species composition remained unexplained. Forward selection revealed that understory species distributions were primarily affected by elevation and aspect. Juniper forest had higher species richness and α-diversity and lower β-diversity in the herb layer of the understory plant community than spruce forest, suggesting that the former may be more important in maintaining understory biodiversity and community stability in alpine coniferous forest ecosystems.

Postbuckling of magneto-electro-elastic CNT-MT composite nanotubes resting on a nonlinear elastic medium in a non-uniform thermal environment

NASA Astrophysics Data System (ADS)

Kamali, M.; Shamsi, M.; Saidi, A. R.

2018-03-01

As a first endeavor, the effect of nonlinear elastic foundation on the postbuckling behavior of smart magneto-electro-elastic (MEE) composite nanotubes is investigated. The composite nanotube is affected by a non-uniform thermal environment. A typical MEE composite nanotube consists of microtubules (MTs) and carbon nanotubes (CNTs) with a MEE cylindrical nanoshell for smart control. It is assumed that the nanoscale layers of the system are coupled by a polymer matrix or filament network depending on the application. In addition to thermal loads, magneto-electro-mechanical loads are applied to the composite nanostructure. Length scale effects are taken into account using the nonlocal elasticity theory. The principle of virtual work and von Karman's relations are used to derive the nonlinear governing differential equations of MEE CNT-MT nanotubes. Using Galerkin's method, nonlinear critical buckling loads are determined. Various types of non-uniform temperature distribution in the radial direction are considered. Finally, the effects of various parameters such as the nonlinear constant of elastic medium, thermal loading factor and small scale coefficient on the postbuckling of MEE CNT-MT nanotubes are studied.

Assessment of hydrogeochemical status of groundwater in a coastal region of Southeast coast of India

NASA Astrophysics Data System (ADS)

Chidambaram, S.; Sarathidasan, J.; Srinivasamoorthy, K.; Thivya, C.; Thilagavathi, R.; Prasanna, M. V.; Singaraja, C.; Nepolian, M.

2018-03-01

A study was conducted in a coastal region of Cuddalore district of Tamil Nadu, India, to identify the hydrogeochemical processes controlling the groundwater chemistry. The major geological units of the study area are sandstone, clay, alluvium, and laterite soils of Tertiary and Quaternary age. A total of 64 groundwater samples were measured for major ions and stable isotopes. Higher electrical conductivity values indicate the poor quality groundwater along the coastal region. Saline water intrusion mainly affects the hydrochemical composition of the aquifer water reflected by Na-Cl-type waters. Cl-/(Cl- + HCO3 -) ratio also indicates the mixing of fresh groundwater with saline water. The results of δD and δ18O analyses show that isotopic compositions of groundwater ranges from - 7.7 to - 2.1‰ for δ18O and from - 55.6 to - 18.5‰ for δD. Correlation and factor analysis were carried out to find the association of ions and to determine the major factors controlling the groundwater chemistry of the region. The study indicates that ion exchange, weathering, salt water intrusion along the coast, and anthropogenic impacts are the major controlling factors for the groundwater chemistry of the region.

Epigenetic Matters: The Link between Early Nutrition, Microbiome, and Long-term Health Development

PubMed Central

Indrio, Flavia; Martini, Silvia; Francavilla, Ruggiero; Corvaglia, Luigi; Cristofori, Fernanda; Mastrolia, Salvatore Andrea; Neu, Josef; Rautava, Samuli; Russo Spena, Giovanna; Raimondi, Francesco; Loverro, Giuseppe

2017-01-01

Epigenetic modifications are among the most important mechanisms by which environmental factors can influence early cellular differentiation and create new phenotypic traits during pregnancy and within the neonatal period without altering the deoxyribonucleic acid sequence. A number of antenatal and postnatal factors, such as maternal and neonatal nutrition, pollutant exposure, and the composition of microbiota, contribute to the establishment of epigenetic changes that can not only modulate the individual adaptation to the environment but also have an influence on lifelong health and disease by modifying inflammatory molecular pathways and the immune response. Postnatal intestinal colonization, in turn determined by maternal flora, mode of delivery, early skin-to-skin contact and neonatal diet, leads to specific epigenetic signatures that can affect the barrier properties of gut mucosa and their protective role against later insults, thus potentially predisposing to the development of late-onset inflammatory diseases. The aim of this review is to outline the epigenetic mechanisms of programming and development acting within early-life stages and to examine in detail the role of maternal and neonatal nutrition, microbiota composition, and other environmental factors in determining epigenetic changes and their short- and long-term effects. PMID:28879172

Merit-Based Incentive Payment System (MIPS): Harsh Choices For Interventional Pain Management Physicians.

PubMed

Manchikanti, Laxmaiah; Helm Ii, Standiford; Benyamin, Ramsin M; Hirsch, Joshua A

2016-01-01

The Merit-based Incentive Payment System (MIPS) was created by the Medicare Access and CHIP Reauthorization Act of 2015 (MACRA) to improve the health of all Americans by providing incentives and policies to improve patient health outcomes. MIPS combines 3 existing programs, Meaningful Use (MU), now called Advancing Care Information (ACI), contributing 25% of the composite score; Physician Quality Reporting System (PQRS), changed to Quality, contributing 50% of the composite score; and Value-based Payment (VBP) system to Resource Use or cost, contributing 10% of the composite score. Additionally, Clinical Practice Improvement Activities (CPIA), contributing 15% of the composite score, create multiple strategic goals to design incentives that drive movement toward delivery system reform principles with inclusion of Advanced Alternative Payment Models (APMs). Under the present proposal, the Centers for Medicare and Medicaid Services (CMS) has estimated approximately 30,000 to 90,000 providers from a total of over 761,000 providers will be exempt from MIPS. About 87% of solo practitioners and 70% of practitioners in groups of less than 10 will be subjected to negative payments or penalties ranging from 4% to 9%. In addition, MIPS also will affect a provider's reputation by making performance measures accessible to consumers and third-party physician rating Web sites.The MIPS composite performance scoring method, at least in theory, utilizes weights for each performance category, exceptional performance factors to earn bonuses, and incorporates the special circumstances of small practices.In conclusion, MIPS has the potential to affect practitioners negatively. Interventional Pain Medicine practitioners must understand the various MIPS measures and how they might participate in order to secure a brighter future. Medicare Access and CHIP Reauthorization Act of 2015, merit-based incentive payment system, quality performance measures, resource use, clinical practice improvement activities, advancing care information performance category.

Fatty Acid Composition of Novel Host Jack Pine Do Not Prevent Host Acceptance and Colonization by the Invasive Mountain Pine Beetle and Its Symbiotic Fungus

PubMed Central

Ishangulyyeva, Guncha; Najar, Ahmed; Curtis, Jonathan M.

2016-01-01

Fatty acids are major components of plant lipids and can affect growth and development of insect herbivores. Despite a large literature examining the roles of fatty acids in conifers, relatively few studies have tested the effects of fatty acids on insect herbivores and their microbial symbionts. Particularly, whether fatty acids can affect the suitability of conifers for insect herbivores has never been studied before. Thus, we evaluated if composition of fatty acids impede or facilitate colonization of jack pine (Pinus banksiana) by the invasive mountain pine beetle (Dendroctonus ponderosae) and its symbiotic fungus (Grosmannia clavigera). This is the first study to examine the effects of tree fatty acids on any bark beetle species and its symbiotic fungus. In a novel bioassay, we found that plant tissues (hosts and non-host) amended with synthetic fatty acids at concentrations representative of jack pine were compatible with beetle larvae. Likewise, G. clavigera grew in media amended with lipid fractions or synthetic fatty acids at concentrations present in jack pine. In contrast, fatty acids and lipid composition of a non-host were not suitable for the beetle larvae or the fungus. Apparently, concentrations of individual, rather than total, fatty acids determined the suitability of jack pine. Furthermore, sampling of host and non-host tree species across Canada demonstrated that the composition of jack pine fatty acids was similar to the different populations of beetle’s historical hosts. These results demonstrate that fatty acids composition compatible with insect herbivores and their microbial symbionts can be important factor defining host suitability to invasive insects. PMID:27583820

Experimental investigation on V isotope equilibrium fractionation factor between metal and silicate melt

NASA Astrophysics Data System (ADS)

Zhang, S.; Zhang, H.; Huang, F.

2017-12-01

Equilibrium fractionation factors of stable isotopes between metal and silicate melt are of vital importance for understanding the isotope variations within meteorites and planetary bodies. The V isotope composition (reported as δ51V = 1000 × [(51V/50Vsample/51V/50VAA)-1] ) of the bulk silicate Earth (BSE) has been estimated as δ51V = -0.7 ± 0.2‰ (2sd) [1], which is significantly heavier than most meteorites by 1‰ [2]. Such isotopic offset may provide insights for the core formation and core-mantle segregation. Therefore, it is important to understand V isotope equilibrium fractionation factor between silicate melt and metal. Nielsen et al. (2014) [2] had performed 3 experiments using starting materials of pure Fe metal and An50Di28Fo22 composition, revealing no resolvable V isotope fractionation. However, it is not clear whether chemical compositions in the melts can affect V isotope fractionations. Therefore, we experimentally calibrated equilibrium V isotope fractionation between Fe metallic and basaltic melt, with particular focus on the effect of Ni and other light elements. Experiments were performed at 1 GPa and 1600 oC using a 3/4″ end-loaded piston cylinder. The starting materials consisted of 1:1 mixture of pure Fe metal and basaltic composition [3]. The isotope equilibrium was assessed using time series experiments combined with the reverse reaction method. Carbon saturation and C-free experiments were achieved by using graphite and silica capsules, respectively. The Ni series experiments were doped with 6 wt% Ni into the starting Fe metal. The metal and silicate phases of samples were mechanically separated, V was purified using a chromatographic technique, and V isotope ratios were measured using MC-ICP-MS [4]. Carbon saturation, C-free experiments and Ni series experiment all show non-resolvable V isotope fractionation between metal and basaltic melt, which indicates that the presence of C and Ni could not affect V isotope fractionation during core formation. More experiments will be performed to explore the effect of Si and S in the metal on V isotope fractionation between metal and silicate melt.References: [1] Prytulak et al. (2013) EPSL 365, 177-189 [2] Nielsen et al. (2014) EPSL 389, 167-175 [3] Cottrell et al. (2009) CG 268, 167-179 [4] Wu et al. (2016) CG 421, 17-25

[Concept of optimal body composition of professional football players].

PubMed

Grigoryan, S

2011-09-01

Body composition and body weight are two of the many factors that contribute to optimal exercise performance. Body weight can influence an athlete's speed, endurance, and power, whereas body composition can affect an athlete's strength, agility, and appearance. Individualized assessment of an athlete's body composition and body weight or body image may be advantageous for the improvement of athletic performance. The purpose of the present research consists in development of physiologically proved modelling characteristic of high performance football players on the basis of the analysis of dynamics (changes) of the major parameters of structure of weight of football players of various ages in process of acquiring game experience and skill. 344 football players from 15 to 35 years old were surveyed. The basic parameters of body composition were determined. It was found that general tendency in dynamics of the basic components of structure of body composition at the end of playing season is expressed in appreciable gain of active cellular weight as analogue of the muscular mass, decrease in the absolute fat contents, increase in endocellular liquid and eritrocyte mass. Comparison of changeable parameters to external criteria of success in competition and tested productivity, adaptive reactions and stability of motivation led to the conclusion that quantitative sports-skill evaluation and forecast of the growth in achievements is possible.

The specificity of host-bat fly interaction networks across vegetation and seasonal variation.

PubMed

Zarazúa-Carbajal, Mariana; Saldaña-Vázquez, Romeo A; Sandoval-Ruiz, César A; Stoner, Kathryn E; Benitez-Malvido, Julieta

2016-10-01

Vegetation type and seasonality promote changes in the species composition and abundance of parasite hosts. However, it is poorly known how these variables affect host-parasite interaction networks. This information is important to understand the dynamics of parasite-host relationships according to biotic and abiotic changes. We compared the specialization of host-bat fly interaction networks, as well as bat fly and host species composition between upland dry forest and riparian forest and between dry and rainy seasons in a tropical dry forest in Jalisco, Mexico. Bat flies were surveyed by direct collection from bats. Our results showed that host-bat fly interaction networks were more specialized in upland dry forest compared to riparian forest. Bat fly species composition was different between the dry and rainy seasons, while host species composition was different between upland dry forest and riparian forest. The higher specialization in upland dry forest could be related to the differences in bat host species composition and their respective roosting habits. Variation in the composition of bat fly species between dry and rainy seasons coincides with the seasonal shifts in their species richness. Our study confirms the high specialization of host-bat fly interactions and shows the importance of biotic and abiotic factors to understand the dynamics of parasite-host interactions.

Development of cesium phosphotungstate salt and chitosan composite membrane for direct methanol fuel cells.

PubMed

Xiao, Yanxin; Xiang, Yan; Xiu, Ruijie; Lu, Shanfu

2013-10-15

A novel composite membrane has been developed by doping cesium phosphotungstate salt (CsxH3-xPW12O40 (0≤x≤3), Csx-PTA) into chitosan (CTS/Csx-PTA) for application in direct methanol fuel cells (DMFCs). Uniform distribution of Csx-PTA nanoparticles has been achieved in the chitosan matrix. The proton conductivity of the composite membrane is significantly affected by the Csx-PTA content in the composite membrane as well as the Cs substitution in PTA. The highest proton conductivity for the CTS/Csx-PTA membranes was obtained with x=2 and Cs2-PTA content of 5 wt%. The value is 6×10(-3) S cm(-1) and 1.75×10(-2) S cm(-1) at 298 K and 353 K, respectively. The methanol permeability of CTS/Cs2-PTA membrane is about 5.6×10(-7), 90% lower than that of Nafion-212 membrane. The highest selectivity factor (φ) was obtained on CTS/Cs2-PTA-5 wt% composite membrane, 1.1×10(4)/Scm(-3)s. The present study indicates the promising potential of CTS/Csx-PTA composite membrane as alternative proton exchange membranes in direct methanol fuel cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

Anthropogenic and natural variability in the composition of sedimentary organic matter of the urbanised coastal zone of Montevideo (Río de la Plata).

PubMed

Bueno, C; Brugnoli, E; Bergamino, L; Muniz, P; García-Rodríguez, F; Figueira, R

2018-01-01

This study is aimed to identify the different sources of sedimentary organic matter (SOM) within Montevideo coastal zone (MCZ). To this end δ 13 C, δ 15 N and C/N ratio were analysed in surface sediments and a sediment core. Sediment core analysis showed that until ~1950CE SOM was mainly marine, observing a shift towards lower δ 13 C in recent sediments, evidencing an estuarine composition. This trend was associated to the climatic variability, which exerted a major influence on the SOM composition, leading to an increased input of terrigenous material and associated anthropogenic contaminants. Surface sediments collected during different El Niño South Oscillation (ENSO) phases did not show inter-annual variability in SOM composition, which was mainly marine in both eastern and western region of MCZ and estuarine in Montevideo Bay. This spatial pattern provides new insights on the dynamics and factors affecting organic matter sources available for primary consumers along the study region. Copyright © 2017 Elsevier Ltd. All rights reserved.

Facile preparation of molecularly imprinted polypyrrole-graphene-multiwalled carbon nanotubes composite film modified electrode for rutin sensing.

PubMed

Yang, Lite; Yang, Juan; Xu, Bingjie; Zhao, Faqiong; Zeng, Baizhao

2016-12-01

In this paper, a novel molecularly imprinted composite film modified electrode was presented for rutin (RT) detection. The modified electrode was fabricated by electropolymerization of pyrrole on a graphene-multiwalled carbon nanotubes composite (G-MWCNTs) coated glassy carbon electrode in the presence of RT. The netlike G-MWCNTs composite, prepared by in situ hydrothermal process, had high conductivity and electrocatalytic activity. At the resulting MIP/G-MWCNTs/GCE electrode RT could produce a sensitive anodic peak in pH 1.87 Britton-Robinson buffer solution. The factors affecting the electrochemical behavior and response of RT on the modified electrode were carefully investigated and optimized. Under the selected conditions, the linear response range of RT was 0.01-1.0μmolL -1 and the detection limit (S/N=3) was 5.0nmolL -1 . The electrode was successfully applied to the determination of RT in buckwheat tea and orange juice samples, and the recoveries for standards added were 93.4-105%. Copyright © 2016 Elsevier B.V. All rights reserved.

Diversity begets diversity? The effects of board composition on the appointment and success of women CEOs.

PubMed

Cook, Alison; Glass, Christy

2015-09-01

Previous research on the effects of leadership diversity on firm outcomes has produced inconsistent and inconclusive findings. While some scholars argue that diversity increases organizational equity and enhances performance, others argue that diversity increases conflict, reduces cooperation and harms performance. This study tests the impact of a variety of compositional factors on firm outcomes. Specifically, we analyze whether and how board composition affects the advancement and mobility of women CEOs and firm performance. Our analysis relies on a unique data set of all Chief Executive Officers (CEOs) and Board of Directors (BODs) in Fortune 500 companies over a ten-year period. We find a marginally significant positive relationship between board diversity and the likelihood of a woman being appointed CEO. We further find that board diversity significantly and positively influences the post-promotion success of women CEOs. Our findings suggest that board composition is critical for the appointment and success of women CEOs, and increasing board diversity should be central to any organizational diversity efforts. Copyright © 2015 Elsevier Inc. All rights reserved.

Fatty acid composition of Swedish bakery products, with emphasis on trans-fatty acids.

PubMed

Trattner, Sofia; Becker, Wulf; Wretling, Sören; Öhrvik, Veronica; Mattisson, Irene

2015-05-15

Trans-fatty acids (TFA) have been associated with increased risk of coronary heart disease, by affecting blood lipids and inflammation factors. Current nutrition recommendations emphasise a limitation of dietary TFA intake. The aim of this study was to investigate fatty acid composition in sweet bakery products, with emphasis on TFA, on the Swedish market and compare fatty acid composition over time. Products were sampled in 2001, 2006 and 2007 and analysed for fatty acid composition by using GC. Mean TFA levels were 0.7% in 2007 and 5.9% in 2001 of total fatty acids. In 1995-97, mean TFA level was 14.3%. In 2007, 3 of 41 products had TFA levels above 2% of total fatty acids. TFA content had decreased in this product category, while the proportion of saturated (SFA) and polyunsaturated (PUFA) fatty acids had increased, mostly through increased levels of 16:0 and 18:2 n-6, respectively. The total fat content remained largely unchanged. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Study of the controlled assembly of DNA gated PEI/Chitosan/SiO2 fluorescent sensor.

PubMed

Chang, Zheng; Mi, Yinghao; Zheng, Xingwang

2018-03-01

In this paper, polyethylenimine (PEI) and Chitosan were simultaneously one-step doped into silicon dioxide (SiO 2 ) nanoparticles to synthesize PEI/Chitosan/SiO 2 composite nanoparticles. The polymer PEI contained a large amount of amino groups, which can realize the amino functionalized SiO 2 nanoparticles. And, the good pore forming effect of Chitosan was introduced into SiO 2 nanoparticles, and the resulting composite nanoparticles also had a porous structure. In pH 7.4 phosphate buffer solution (PBS), the amino groups of PEI had positive charges, and therefore the fluorescein sodium dye molecule can be loaded into the channels of PEI/Chitosan/SiO 2 composite nanoparticles by electrostatic adsorption. Furthermore, utilizing the diversity of DNA molecular conformation, we designed a high sensitive controllable assembly of DNA gated fluorescent sensor based on PEI/Chitosan/SiO 2 composite nanoparticles as loading materials. The factors affecting the sensing performance of the sensor were investigated, and the sensing mechanism was also further studied. Copyright © 2017 John Wiley & Sons, Ltd.

Preventive effects of raloxifene treatment on agerelated weight loss in postmenopausal women.

PubMed

Urano, Tomohiko; Shiraki, Masataka; Kuroda, Tatsuhiko; Tanaka, Shiro; Uenishi, Kazuhiro; Inoue, Satoshi

2017-01-01

Decline of body weight and body mass index (BMI) with aging is a major risk factor for osteoporosis and fracture, suggesting that treatment for osteoporosis may affect body composition. However, the effects of treatment for osteoporosis on body composition are not well known. The present study aimed to identify the relationship between raloxifene treatment and body composition markers. We measured bone mineral density (BMD), body composition, and bone remodeling markers in 236 Japanese postmenopausal women with raloxifene treatment (N = 50) and without treatment by any osteoporosis drug (N = 186) for 5 years and analyzed the relationship of these with BMD, BMI, body weight, and biochemical markers. The mean (SD) age of the participants was 65.5 (9.3) years. Percent-changes in body weight and BMI were significantly different between women taking raloxifene and those not taking any osteoporosis drugs (P = 0.03 and 0.048, respectively). Raloxifene treatment was a significant independent determinant of body weight and BMI. Long-term treatment with raloxifene prevents age-related weight loss.

Hydro-edaphic conditions defining richness and species composition in savanna areas of the northern Brazilian Amazonia

PubMed Central

Araújo, Maria Aparecida de Moura; da Rocha, Antônio Elielson Sousa; Miranda, Izildinha de Souza

2017-01-01

Abstract Background Studies on plant communities in the Amazon have reported that different hydro-edaphic conditions can affect the richness and the species composition of different ecosystems. However, this aspect is poorly known in the different savanna habitats. Understanding how populations and plant communities are distributed in these open vegetation areas is important to improve the knowledge about which environmental variables influence the occurrence and diversity of plants in this type of regional ecosystem. Thus, this study investigated the richness and composition of plant species in two savanna areas of the northern Brazilian Amazonia, using the coverage (%) of the different life forms observed under different hydro-edaphic conditions as a structural reference. New information We report 128 plant species classified in 34 botanical families distributed in three savanna habitats with different levels of hydro-edaphic restrictions. In this study, the habitats are conceptually presented and they integrate environmental information (edaphic factors and drainage type), which determines differences between floristic composition, species richness and coverage (%) of plant life forms. PMID:28848372

Body composition, cardiometabolic risk factors, physical activity, and inflammatory markers in premenopausal women after a 10-year follow-up: a MONET study.

PubMed

Razmjou, Sahar; Abdulnour, Joseph; Bastard, Jean-Philippe; Fellahi, Soraya; Doucet, Éric; Brochu, Martin; Lavoie, Jean-Marc; Rabasa-Lhoret, Rémi; Prud'homme, Denis

2018-01-01

Menopausal transition and postmenopause are usually associated with changes in body composition and a decrease in physical activity energy expenditure (PAEE). This study investigated body composition, cardiometabolic risk factors, PAEE, and inflammatory markers in premenopausal women after a 10-year follow-up. In all, 102 premenopausal women participated in the 5-year observational longitudinal Montreal Ottawa New Emerging Team (MONET) study. This present substudy included 48 participants (age: 60.0 ± 1.7 years; body mass index: 23.2 ± 2.2 kg/m) 6.0 ± 0.3 years after completion of the initial MONET study. Measures included body composition, waist circumference (WC), fasting glucose and insulin levels, insulin sensitivity (QUICKI model), plasma lipid levels, PAEE, and inflammatory markers. Compared with baseline measures of the MONET study, analyses revealed no significant increase in body weight, although there were significant increases in WC, fat mass (FM), % FM, total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol, haptoglobin, apolipoprotein B, ferritin, adiponectin, and soluble cluster of differentiation 14 (all P < 0.001) after the 10-year follow-up. However, significant decreases were observed for fat-free mass, PAEE, fasting glucose levels, interleukin-8 levels, and soluble tumor necrosis factor receptors 1 and 2 (sTNFR-1 and sTNFR-2) levels (all P < 0.05). To determine the effect of postmenopausal years, data were restructured based on final menstrual period (FMP), and one-way analyses of variance were performed.Waist circumference, % FM, total cholesterol, high-density lipoprotein cholesterol, apolipoprotein B, ferritin, adiponectin, and soluble cluster of differentiation 14 were higher in early and late postmenopausal periods in these women. sTNFR-1 and sTNFR-2 levels were higher at the FMP and early postmenopausal years as compared with the late postmenopausal periods. Finally, interleukin-8 levels were lower in years after FMP. The number of years elapsed since the FMP can affect body composition, cardiometabolic risk factors, and inflammatory markers in healthy premenopausal women going through menopausal transition and postmenopausal periods.

Associations between maternal lifestyle factors and neonatal body composition in the Screening for Pregnancy Endpoints (Cork) cohort study.

PubMed

Dahly, Darren L; Li, Xia; Smith, Hazel A; Khashan, Ali S; Murray, Deirdre M; Kiely, Mairead E; O'B Hourihane, Jonathan; McCarthy, Fergus P; Kenny, Louise C; Kearney, Patricia M

2018-02-01

Neonatal body composition likely mediates fetal influences on life long chronic disease risk. A better understanding of how maternal lifestyle is related to newborn body composition could thus inform intervention efforts. Using Cork participant data (n = 1754) from the Screening for Pregnancy Endpoints (SCOPE) cohort study [ECM5(10)05/02/08], we estimated how pre-pregnancy body size, gestational weight gain, exercise, alcohol, smoking and diet were related to neonatal fat and fat-free mass, as well as length and gestational age at birth, using quantile regression. Maternal factors were measured by a trained research midwife at 15 gestational weeks, in addition to a 3rd trimester weight measurement used to calculate weight gain. Infant body composition was measured using air-displacement plethysmography. Healthy (versus excess) gestational weight gain was associated with lower median fat-free mass [-112 g, 95% confidence interval (CI): -47 to -176) and fat mass (-33 g, 95% CI: -1 to -65) in the offspring; and a 103 g decrease in the 95th centile of fat mass (95% CI: -33 to -174). Maternal normal weight status (versus obesity) was associated with lower median fat mass (-48 g, 95% CI: -12 to -84). At the highest centiles, fat mass was lower among infants of women who engaged in frequent moderate-intensity exercise early in the pregnancy (-92 g at the 95th centile, 95% CI: -168 to -16). Lastly, women who never smoked tended to have longer babies with more fat mass and fat-free mass. No other lifestyle factors were strongly related to infant body composition. These results suggest that supporting healthy maternal lifestyles could reduce the risk of excess fat accumulation in the offspring, without adversely affecting fat-free mass development, length or gestational age. © The Author 2017; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association

Herbivore species identity and composition affect soil enzymatic activity through altered plant composition in a coastal tallgrass prairie

USDA-ARS?s Scientific Manuscript database

Although single species of herbivores are known to affect soil microbial communities, the effects of herbivore species identity and functional composition on soil microbes is unknown. We tested the effects of single species of orthopterans and multiple species combinations on soil enzymatic activity...

Relationship between Maceral of Coal and Coal-bed Methane adsorption ability in Sihe Coalmine of Qinshui Basin, China

NASA Astrophysics Data System (ADS)

Wang, M. S.; Zou, G. G.; Zhu, R. B.

2018-05-01

Maceral components and its content of coal were divided based on the microscopic characteristics of coal. The Langmuir volume and the Langmuir pressure were tested, and the Langmuir volume represents the adsorption capacity of coal. The formation of coal bed methane is affected by the partition of the maceral components in coal. Therefore, the relationship between maceral composition and coal bed methane adsorption capacity of coal was analyzed. The results show that the maceral components of coal are dominated by vitrinite and inertinite in the study area, and the content of inertinite is below 32%. The vitrinite group has a negative linear correlation with the Langmuir volume, and the inertia composition has a positive linear correlation with it. The cellular structures in the inertinite are the main site of coal bed methane enrichment. The microstructure of coal affects the coalbed methane content and the stage of hydrocarbon generation in coal. This indicates that the microstructure of coal is one of the important factors influencing the adsorption capacity of coal seam.

Building a Beneficial Microbiome from Birth12

PubMed Central

Castanys-Muñoz, Esther; Martin, Maria J; Vazquez, Enrique

2016-01-01

The microbiota has recently been recognized as a driver of health that affects the immune, nervous, and metabolic systems. This influence is partially exerted through the metabolites produced, which may be relevant for optimal infant development and health. The gut microbiota begins developing early in life, and this initial colonization is remarkably important because it may influence long-term microbiota composition and activity. Considering that the microbiome may play a key role in health and disease, maintaining a protective microbiota could be critical in preventing dysbiosis-related diseases such as allergies, autoimmunity disorders, and metabolic syndrome. Breast milk and milk glycans in particular are thought to play a major role in shaping the early-life microbiota and promoting its development, thus affecting health. This review describes some of the effects the microbiota has on the host and discusses the role microbial metabolites play in shaping newborn health and development. We describe the gut microbiota structure and function during early life and the factors that determine its composition and hypothesize about the effects of human milk oligosaccharides and other prebiotic fibers on the neonatal microbiota. PMID:26980815

Building a Beneficial Microbiome from Birth.

PubMed

Castanys-Muñoz, Esther; Martin, Maria J; Vazquez, Enrique

2016-03-01

The microbiota has recently been recognized as a driver of health that affects the immune, nervous, and metabolic systems. This influence is partially exerted through the metabolites produced, which may be relevant for optimal infant development and health. The gut microbiota begins developing early in life, and this initial colonization is remarkably important because it may influence long-term microbiota composition and activity. Considering that the microbiome may play a key role in health and disease, maintaining a protective microbiota could be critical in preventing dysbiosis-related diseases such as allergies, autoimmunity disorders, and metabolic syndrome. Breast milk and milk glycans in particular are thought to play a major role in shaping the early-life microbiota and promoting its development, thus affecting health. This review describes some of the effects the microbiota has on the host and discusses the role microbial metabolites play in shaping newborn health and development. We describe the gut microbiota structure and function during early life and the factors that determine its composition and hypothesize about the effects of human milk oligosaccharides and other prebiotic fibers on the neonatal microbiota. © 2016 American Society for Nutrition.

ER phospholipid composition modulates lipogenesis during feeding and in obesity.

PubMed

Rong, Xin; Wang, Bo; Palladino, Elisa Nd; de Aguiar Vallim, Thomas Q; Ford, David A; Tontonoz, Peter

2017-10-02

Sterol regulatory element-binding protein 1c (SREBP-1c) is a central regulator of lipogenesis whose activity is controlled by proteolytic cleavage. The metabolic factors that affect its processing are incompletely understood. Here, we show that dynamic changes in the acyl chain composition of ER phospholipids affect SREBP-1c maturation in physiology and disease. The abundance of polyunsaturated phosphatidylcholine in liver ER is selectively increased in response to feeding and in the setting of obesity-linked insulin resistance. Exogenous delivery of polyunsaturated phosphatidylcholine to ER accelerated SREBP-1c processing through a mechanism that required an intact SREBP cleavage-activating protein (SCAP) pathway. Furthermore, induction of the phospholipid-remodeling enzyme LPCAT3 in response to liver X receptor (LXR) activation promoted SREBP-1c processing by driving the incorporation of polyunsaturated fatty acids into ER. Conversely, LPCAT3 deficiency increased membrane saturation, reduced nuclear SREBP-1c abundance, and blunted the lipogenic response to feeding, LXR agonist treatment, or obesity-linked insulin resistance. Desaturation of the ER membrane may serve as an auxiliary signal of the fed state that promotes lipid synthesis in response to nutrient availability.

Shift in soil microbial communities with shrub encroachment in Inner Mongolia grasslands, China

NASA Astrophysics Data System (ADS)

Shen, H.; Li, H.; Zhang, J.; Hu, H.; Chen, L.; Zhu, Y.; Fang, J.

2017-12-01

The ongoing expansion of shrub encroachment into grasslands represents a unique form of land cover change. How this process affects soil microbial communities is poorly understood. In this study, we aim to assess the effects of shrub encroachment on soil microbial biomass, abundance and composition by comparing data between shrub patches and neighboring herb patches in shrub-encroached grasslands (SEGs) in Inner Mongolia, China. Fourteen SEG sites from two ecosystem types (typical and desert grasslands) were investigated. The phospholipid fatty acid (PLFA) method was used to analyze the composition and biomass of the soil microbial community. Our results showed that the top-soil microbial biomass and abundances of gram-negative bacteria, arbuscular mycorrhizal fungi, and actinomycetes were significantly higher in shrub patches than in herb patches in both typical and desert grasslands (P < 0.05). The fungi to bacteria ratio was significantly higher in shrub patches than in herb patches in desert grassland (P < 0.05). The microbial biomass was positively associated with mean annual precipitation, total nitrogen and available phosphorus, and negatively associated with mean annual temperature. Our results also indicated that the variation in microbial composition was largely explained by edaphic factors, followed by climate factors. In conclusion, shrub encroachment in Inner Mongolia grasslands has significantly influenced the structure and abundance of soil microbial communities, which makes the microbial communities toward a fresh organic carbon-based structure. This study highlights the importance of edaphic and climate factors in microbial community shifts in SEGs.

Analysis of a Modern Hybrid and an Ancient Sugarcane Implicates a Complex Interplay of Factors in Affecting Recalcitrance to Cellulosic Ethanol Production

PubMed Central

Ricci-Silva, Maria Esther; Rhys Williams, Thomas Christopher; Alves Peçanha, Diego; Contin Ventrella, Marília; Rencoret, Jorge; Ralph, John; Pereira Barbosa, Márcio Henrique; Loureiro, Marcelo

2015-01-01

Abundant evidence exists to support a role for lignin as an important element in biomass recalcitrance. However, several independent studies have also shown that factors apart from lignin are also relevant and overall, the relative importance of different recalcitrance traits remains in dispute. In this study we used two genetically distant sugarcane genotypes, and performed a correlational study with the variation in anatomical parameters, cell wall composition, and recalcitrance factors between these genotypes. In addition we also tracked alterations in these characteristics in internodes at different stages of development. Significant differences in the development of the culm between the genotypes were associated with clear differential distributions of lignin content and composition that were not correlated with saccharification and fermentation yield. Given the strong influence of the environment on lignin content and composition, we hypothesized that sampling within a single plant could allow us to more easily interpret recalcitrance and changes in lignin biosynthesis than analysing variations between different genotypes with extensive changes in plant morphology and culm anatomy. The syringyl/guaiacyl (S/G) ratio was higher in the oldest internode of the modern genotype, but S/G ratio was not correlated with enzymatic hydrolysis yield nor fermentation efficiency. Curiously we observed a strong positive correlation between ferulate ester level and cellulose conversion efficiency. Together, these data support the hypothesis that biomass enzymatic hydrolysis recalcitrance is governed by a quantitative heritage rather than a single trait. PMID:26252208

Salt marsh sediment bacteria: their distribution and response to external nutrient inputs.

PubMed

Bowen, Jennifer L; Crump, Byron C; Deegan, Linda A; Hobbie, John E

2009-08-01

A primary focus among microbial ecologists in recent years has been to understand controls on the distribution of microorganisms in various habitats. Much less attention has been paid to the way that environmental disturbance interacts with processes that regulate bacterial community composition. We determined how human disturbance affected the distribution and community structure of salt marsh sediment bacteria by using denaturing gradient gel electrophoresis of 16S rRNA in five different habitats in each of four salt marshes located in northeastern Massachusetts, USA. Two of the four marsh creeks were experimentally enriched 15 x above background by the addition of nitrogen and phosphorus fertilizers for two or more growing seasons. Our results indicate that extrinsic factors acting at broad scales do not influence the distribution of salt marsh sediment bacteria. Intrinsic factors, controlled by local-scale environmental heterogeneity, do play a role in structuring these sediment microbial communities, although nutrient enrichment did not have a consequential effect on the microbial community in most marsh habitats. Only in one habitat, a region of the marsh creek wall that is heavily colonized by filamentous algae, did we see any effect of fertilization on the microbial community structure. When similar habitats were compared among marshes, there was considerable convergence in the microbial community composition during the growing season. Environmental factors that correlated best with microbial community composition varied with habitat, suggesting that habitat-specific intrinsic forces are primarily responsible for maintaining microbial diversity in salt marsh sediments.

Tree diversity affects chlorophyll a fluorescence and other leaf traits of tree species in a boreal forest.

PubMed

Pollastrini, Martina; Nogales, Ana Garcia; Benavides, Raquel; Bonal, Damien; Finer, Leena; Fotelli, Mariangela; Gessler, Arthur; Grossiord, Charlotte; Radoglou, Kalliopi; Strasser, Reto J; Bussotti, Filippo

2017-02-01

An assemblage of tree species with different crown properties creates heterogeneous environments at the canopy level. Changes of functional leaf traits are expected, especially those related to light interception and photosynthesis. Chlorophyll a fluorescence (ChlF) properties in dark-adapted leaves, specific leaf area, leaf nitrogen content (N) and carbon isotope composition (δ13C) were measured on Picea abies (L.) H.Karst., Pinus sylvestris L. and Betula pendula Roth. in monospecific and mixed boreal forests in Europe, in order to test whether they were affected by stand species richness and composition. Photosynthetic efficiency, assessed by induced emission of leaf ChlF, was positively influenced in B. pendula by species richness, whereas P. abies showed higher photosynthetic efficiency in monospecific stands. Pinus sylvestris had different responses when it coexisted with P. abies or B. pendula. The presence of B. pendula, but not of P. abies, in the forest had a positive effect on the efficiency of photosynthetic electron transport and N in P. sylvestris needles, and the photosynthetic responses were positively correlated with an increase of leaf δ13C. These effects on P. sylvestris may be related to high light availability at the canopy level due to the less dense canopy of B. pendula. The different light requirements of coexisting species was the most important factor affecting the distribution of foliage in the canopy, driving the physiological responses of the mixed species. Future research directions claim to enhance the informative potential of the methods to analyse the responses of pure and mixed forests to environmental factors, including a broader set of plant species' functional traits and physiological responses. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Bacterial community structure and function shift along a successional series of tidal flats in the Yellow River Delta

PubMed Central

Lv, Xiaofei; Ma, Bin; Yu, Junbao; Chang, Scott X.; Xu, Jianming; Li, Yunzhao; Wang, Guangmei; Han, Guangxuan; Bo, Guan; Chu, Xiaojing

2016-01-01

Coastal ecosystems play significant ecological and economic roles but are threatened and facing decline. Microbes drive various biogeochemical processes in coastal ecosystems. Tidal flats are critical components of coastal ecosystems; however, the structure and function of microbial communities in tidal flats are poorly understood. Here we investigated the seasonal variations of bacterial communities along a tidal flat series (subtidal, intertidal and supratidal flats) and the factors affecting the variations. Bacterial community composition and diversity were analyzed over four seasons by 16S rRNA genes using the Ion Torrent PGM platform. Bacterial community composition differed significantly along the tidal flat series. Bacterial phylogenetic diversity increased while phylogenetic turnover decreased from subtidal to supratidal flats. Moreover, the bacterial community structure differed seasonally. Canonical correspondence analysis identified salinity as a major environmental factor structuring the microbial community in the sediment along the successional series. Meanwhile, temperature and nitrite concentration were major drivers of seasonal microbial changes. Despite major compositional shifts, nitrogen, methane and energy metabolisms predicted by PICRUSt were inhibited in the winter. Taken together, this study indicates that bacterial community structure changed along the successional tidal flat series and provides new insights on the characteristics of bacterial communities in coastal ecosystems. PMID:27824160

Bacterial community structure and function shift along a successional series of tidal flats in the Yellow River Delta.

PubMed

Lv, Xiaofei; Ma, Bin; Yu, Junbao; Chang, Scott X; Xu, Jianming; Li, Yunzhao; Wang, Guangmei; Han, Guangxuan; Bo, Guan; Chu, Xiaojing

2016-11-08

Coastal ecosystems play significant ecological and economic roles but are threatened and facing decline. Microbes drive various biogeochemical processes in coastal ecosystems. Tidal flats are critical components of coastal ecosystems; however, the structure and function of microbial communities in tidal flats are poorly understood. Here we investigated the seasonal variations of bacterial communities along a tidal flat series (subtidal, intertidal and supratidal flats) and the factors affecting the variations. Bacterial community composition and diversity were analyzed over four seasons by 16S rRNA genes using the Ion Torrent PGM platform. Bacterial community composition differed significantly along the tidal flat series. Bacterial phylogenetic diversity increased while phylogenetic turnover decreased from subtidal to supratidal flats. Moreover, the bacterial community structure differed seasonally. Canonical correspondence analysis identified salinity as a major environmental factor structuring the microbial community in the sediment along the successional series. Meanwhile, temperature and nitrite concentration were major drivers of seasonal microbial changes. Despite major compositional shifts, nitrogen, methane and energy metabolisms predicted by PICRUSt were inhibited in the winter. Taken together, this study indicates that bacterial community structure changed along the successional tidal flat series and provides new insights on the characteristics of bacterial communities in coastal ecosystems.

Evaluation of the sensitivity and fatigue performance of embedded piezopolymer sensor systems in sandwich composite laminates

NASA Astrophysics Data System (ADS)

Chrysochoidis, N. A.; Gutiérrez, E.

2015-02-01

It has been claimed that embedding piezoceramic devices as structural diagnostic systems in advanced composite structures may introduce mechanical impedance mismatches that favor the formation of intralaminar defects. This and other factors, such as cost and their high strain sensitivity, have motivated the use of thin-film piezopolymer sensors. In this paper, we examine the performance of sandwich composite panels fitted with embedded piezopolymer sensors. Our experiments examine both how such thin-film sensors perform within a structure and how the inclusion of sensor films affects structural performance. Strain-controlled tests on sandwich panels subjected to three-point bending under wide-ranging static and dynamic strains lead us to conclude that embedding thin piezopolymer films has no marked reduction on the tensile strength for a wide range of strain loading paths and magnitudes, and that the resilience of the embedded sensor is itself satisfactory, even up to the point of structural failure. Comparing baseline data obtained from standard surface-mounted sensors and foil gauges, we note that whereas it is possible to match experimental and theoretical strain sensitivities, key properties—especially the pronounced orthotropic electromechanical factor of such films—must be duly considered before an effective calibration can take place.

Effect of pH and ionic strength on exposure and toxicity of encapsulated lambda-cyhalothrin to Daphnia magna.

PubMed

Son, Jino; Hooven, Louisa A; Harper, Bryan; Harper, Stacey L

2015-12-15

Encapsulation of pesticide active ingredients in polymers has been widely employed to control the release of poorly water-soluble active ingredients. Given the high dispersibility of these encapsulated pesticides in water, they are expected to behave differently compared to their active ingredients; however, our current understanding of the fate and effects of encapsulated pesticides is still limited. In this study, we employed a central composite design (CCD) to investigate how pH and ionic strength (IS) affect the hydrodynamic diameter (HDD) and zeta potential of encapsulated λ-cyhalothrin and how those changes affect the exposure and toxicity to Daphnia magna. R(2) values greater than 0.82 and 0.84 for HDD and zeta potential, respectively, irrespective of incubation time suggest those changes could be predicted as a function of pH and IS. For HDD, the linear factor of pH and quadratic factor of pH×pH were found to be the most significant factors affecting the change of HDD at the beginning of incubation, whereas the effects of IS and IS×IS became significant as incubation time increased. For zeta potential, the linear factor of IS and quadratic factor of IS×IS were found to be the most dominant factors affecting the change of zeta potential of encapsulated λ-cyhalothrin, irrespective of incubation time. The toxicity tests with D. magna under exposure conditions in which HDD or zeta potential of encapsulated λ-cyhalothrin was maximized or minimized in the overlying water also clearly showed the worst-case exposure condition to D. magna was when the encapsulated λ-cyhalothrin is either stable or small in the overlying water. Our results show that water quality could modify the fate and toxicity of encapsulated λ-cyhalothrin in aquatic environments, suggesting understanding their aquatic interactions are critical in environmental risk assessment. Herein, we discuss the implications of our findings for risk assessment. Copyright © 2015 Elsevier B.V. All rights reserved.

Real world vehicle fleet emission factors: Seasonal and diurnal variations in traffic related air pollutants

NASA Astrophysics Data System (ADS)

Wang, Jonathan M.; Jeong, Cheol-Heon; Zimmerman, Naomi; Healy, Robert M.; Evans, Greg J.

2018-07-01

Temporal variations of vehicle emissions are affected by various compounding factors in the real world. The focus of this study is to determine the effects of ambient conditions and post-tailpipe changes on traffic emissions measured in the near-road region. Emission factors allowed for the isolation of the traffic signal and accounted for effects of local meteorology and dilution. Five month-long measurement campaigns were conducted at an urban near-road site that exhibited a broad range of ambient conditions with temperatures ranging between -18 and +30 °C. Particle number emission factors were 2.0× higher in the winter relative to the summer, which was attributed to changes in particles post-tailpipe. Conversely, toluene emissions were 2.5× higher in the summer relative to the winter, attributed to changes in fuel composition. Diurnal trends of emission factors showed substantial increases in emissions during the morning rush hour for black carbon (1.9×), particle number (2.4×), and particle-bound polycyclic aromatic hydrocarbons (3.0×), affected by fleet make-up. In contrast, particle number emission factors were highest midday with mean values 3.7× higher than at night. This midday increase was attributed to particle formation or growth from local traffic emissions and showed different wind direction dependence than regional events.

Litter type affects the activity of aerobic decomposers in a boreal peatland more than site nutrient and water table regimes

NASA Astrophysics Data System (ADS)

Straková, P.; Niemi, R. M.; Freeman, C.; Peltoniemi, K.; Toberman, H.; Heiskanen, I.; Fritze, H.; Laiho, R.

2011-09-01

Peatlands are carbon (C) storage ecosystems sustained by a high water table (WT). High WT creates anoxic conditions that suppress the activity of aerobic decomposers and provide conditions for peat accumulation. Peatland function can be dramatically affected by WT drawdown caused by climate and/or land-use change. Aerobic decomposers are directly affected by WT drawdown through environmental factors such as increased oxygenation and nutrient availability. Additionally, they are indirectly affected via changes in plant community composition and litter quality. We studied the relative importance of direct and indirect effects of WT drawdown on aerobic decomposer activity in plant litter at two stages of decomposition (incubated in the field for 1 or 2 years). We did this by profiling 11 extracellular enzymes involved in the mineralization of organic C, nitrogen (N), phosphorus (P) and sulphur. Our study sites represented a three-stage chronosequence from pristine to short-term (years) and long-term (decades) WT drawdown conditions under two nutrient regimes (bog and fen). The litter types included reflected the prevalent vegetation: Sphagnum mosses, graminoids, shrubs and trees. Litter type was the main factor shaping microbial activity patterns and explained about 30 % of the variation in enzyme activities and activity allocation. Overall, enzyme activities were higher in vascular plant litters compared to Sphagnum litters, and the allocation of enzyme activities towards C or nutrient acquisition was related to the initial litter quality (chemical composition). Direct effects of WT regime, site nutrient regime and litter decomposition stage (length of incubation period) summed to only about 40 % of the litter type effect. WT regime alone explained about 5 % of the variation in enzyme activities and activity allocation. Generally, enzyme activity increased following the long-term WT drawdown and the activity allocation turned from P and N acquisition towards C acquisition. This caused an increase in the rate of litter decomposition. The effects of the short-term WT drawdown were minor compared to those of the long-term WT drawdown: e.g., the increase in the activity of C-acquiring enzymes was up to 120 % (bog) or 320 % (fen) higher after the long-term WT drawdown compared to the short-term WT drawdown. In general, the patterns of microbial activity as well as their responses to WT drawdown depended on peatland type: e.g., the shift in activity allocation to C-acquisition was up to 100 % stronger at the fen compared to the bog. Our results imply that changes in plant community composition in response to persistent WT drawdown will strongly affect the C dynamics of peatlands. The predictions of decomposer activity under changing climate and/or land-use thus cannot be based on the direct effects of the changed environment only, but need to consider the indirect effects of environmental changes: the changes in plant community composition, their dependence on peatland type, and their time scale.

Probabilistic simulation of stress concentration in composite laminates

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Murthy, P. L. N.; Liaw, L.

1993-01-01

A computational methodology is described to probabilistically simulate the stress concentration factors in composite laminates. This new approach consists of coupling probabilistic composite mechanics with probabilistic finite element structural analysis. The probabilistic composite mechanics is used to probabilistically describe all the uncertainties inherent in composite material properties while probabilistic finite element is used to probabilistically describe the uncertainties associated with methods to experimentally evaluate stress concentration factors such as loads, geometry, and supports. The effectiveness of the methodology is demonstrated by using it to simulate the stress concentration factors in composite laminates made from three different composite systems. Simulated results match experimental data for probability density and for cumulative distribution functions. The sensitivity factors indicate that the stress concentration factors are influenced by local stiffness variables, by load eccentricities and by initial stress fields.

Chemistry of surface water at a volcanic summit area, Norikura, central Japan: multivariate statistical approach.

PubMed

Anazaw, K; Ohmori, L H

2001-11-01

Many hydrochemical studies on chemical formation of shallow ground water have been reported as results of water-rock interaction, and contamination of paleo-brine or human activities, whereas the preliminary formation of precipitation source in the recharged region has not been established yet. The purpose of this research work is to clarify the geochemical process of water formation from a water source unpolluted by seawater or human activity. Norikura volcano, located in western part of central Japan provided a suitable source for this research purpose, and hence chemical compositions of water samples from the summit and the mountainside area of Norikura volcano were determined. Most samples in the summit area showed very low electrical conductivity, and lower than 12 microS/cm. On the basis of the chemical compositions, principal component analysis (PCA) and factor analysis (FA), such as kinds of multivariate statistical techniques were used to extract geochemical factors affecting hydrochemical process. As a result, three factors were extracted. The first factor showed high loading on K+, Ca2+, SO2 and SiO2, and this factor was interpreted due to influence of the chemical interaction between acidic precipitated water and rocks. The second factor showed high loading on Na+ and Cl-, and it was assumed to be an influence of seawater salt. The third factor showed loading on NO3-, and it was interpreted to be caused by biochemical effect of vegetation. The proportionate contributions of these factors to the evolution of water chemical composition were found to be 45%, 20%, and 10% for factors 1, 2 and 3, respectively. The same exploration at the mountainside of Norikura volcano revealed that the chemical variances of the non-geothermal water samples were highly influenced by water-rock interactions. The silicate dissolution showed 45% contribution for all chemical variances, while the adsorption of Ca2+ and Mg2+ by precipitation or ion exchange showed 20% contribution. The seawater salt influence or biochemical effect was statistically negligible in this area. The clear differentiation of geochemical process on water formation was found between the summit area and the mountainside area.

Sex differences in negative affect and lapse behavior during acute tobacco abstinence: a laboratory study.

PubMed

Pang, Raina D; Leventhal, Adam M

2013-08-01

Heightened negative affect during acute tobacco abstinence in women relative to men could be an important factor underlying sex differences in smoking motivation. However, little controlled experimental work addresses this hypothesis. The current study investigated sex differences in withdrawal-related negative affect, time to start smoking on a lab analogue smoking lapse task, and the interrelation between sex, withdrawal-related negative affect, and smoking lapse behavior. Following a baseline session, current smokers (women: n = 68, men: n = 131) attended two counterbalanced lab sessions (16 hours smoking abstinence and ad libitum smoking) during which they completed self-report measures of mood and withdrawal symptoms followed by a laboratory analogue smoking lapse task. In this task participants are monetarily rewarded for delaying smoking. Performance on this task serves as an analogue model of smoking lapse behavior by measuring smoker's capability to resist temptation to smoke under conditions where abstinence is advantageous. Females showed greater abstinence induced increases in composite negative affect as well as several particular negative affect states (i.e., POMS Anger, Anxiety, Depression, and Confusion, ps < .05) but no differences in abstinence induced changes in other forms of affect or craving. Females also exhibited marginally greater abstinence induced decreases in their willingness to delay smoking for money (p = .10), which was mediated by abstinence induced increases in anger (p < .05). These results suggest that differential sensitivity to abstinence induced negative affect, particularly anger, could underlie sex specific smoking patterns. Negative affect during tobacco abstinence may be an important factor for understanding and treating nicotine addiction in women. PsycINFO Database Record (c) 2013 APA, all rights reserved

Forecasting of municipal solid waste quantity in a developing country using multivariate grey models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Intharathirat, Rotchana, E-mail: rotchana.in@gmail.com; Abdul Salam, P., E-mail: salam@ait.ac.th; Kumar, S., E-mail: kumar@ait.ac.th

Highlights: • Grey model can be used to forecast MSW quantity accurately with the limited data. • Prediction interval overcomes the uncertainty of MSW forecast effectively. • A multivariate model gives accuracy associated with factors affecting MSW quantity. • Population, urbanization, employment and household size play role for MSW quantity. - Abstract: In order to plan, manage and use municipal solid waste (MSW) in a sustainable way, accurate forecasting of MSW generation and composition plays a key role. It is difficult to carry out the reliable estimates using the existing models due to the limited data available in the developingmore » countries. This study aims to forecast MSW collected in Thailand with prediction interval in long term period by using the optimized multivariate grey model which is the mathematical approach. For multivariate models, the representative factors of residential and commercial sectors affecting waste collected are identified, classified and quantified based on statistics and mathematics of grey system theory. Results show that GMC (1, 5), the grey model with convolution integral, is the most accurate with the least error of 1.16% MAPE. MSW collected would increase 1.40% per year from 43,435–44,994 tonnes per day in 2013 to 55,177–56,735 tonnes per day in 2030. This model also illustrates that population density is the most important factor affecting MSW collected, followed by urbanization, proportion employment and household size, respectively. These mean that the representative factors of commercial sector may affect more MSW collected than that of residential sector. Results can help decision makers to develop the measures and policies of waste management in long term period.« less

Analysis of transcriptome data reveals multifactor constraint on codon usage in Taenia multiceps.

PubMed

Huang, Xing; Xu, Jing; Chen, Lin; Wang, Yu; Gu, Xiaobin; Peng, Xuerong; Yang, Guangyou

2017-04-20

Codon usage bias (CUB) is an important evolutionary feature in genomes that has been widely observed in many organisms. However, the synonymous codon usage pattern in the genome of T. multiceps remains to be clarified. In this study, we analyzed the codon usage of T. multiceps based on the transcriptome data to reveal the constraint factors and to gain an improved understanding of the mechanisms that shape synonymous CUB. Analysis of a total of 8,620 annotated mRNA sequences from T. multiceps indicated only a weak codon bias, with mean GC and GC3 content values of 49.29% and 51.43%, respectively. Our analysis indicated that nucleotide composition, mutational pressure, natural selection, gene expression level, amino acids with grand average of hydropathicity (GRAVY) and aromaticity (Aromo) and the effective selection of amino-acids all contributed to the codon usage in T. multiceps. Among these factors, natural selection was implicated as the major factor affecting the codon usage variation in T. multiceps. The codon usage of ribosome genes was affected mainly by mutations, while the essential genes were affected mainly by selection. In addition, 21codons were identified as "optimal codons". Overall, the optimal codons were GC-rich (GC:AU, 41:22), and ended with G or C (except CGU). Furthermore, different degrees of variation in codon usage were found between T. multiceps and Escherichia coli, yeast, Homo sapiens. However, little difference was found between T. multiceps and Taenia pisiformis. In this study, the codon usage pattern of T. multiceps was analyzed systematically and factors affected CUB were also identified. This is the first study of codon biology in T. multiceps. Understanding the codon usage pattern in T. multiceps can be helpful for the discovery of new genes, molecular genetic engineering and evolutionary studies.

Behavior of plywood and fiberglass steel composite tube structures subjected to impact loading

NASA Astrophysics Data System (ADS)

Armaghani, Seyamend Bilind

Paratransit buses are custom built as the major vehicle manufacturer produces the custom built passenger cage installed on the chassis for the Paratransit bus. In order for these Paratransit bus members to be sufficient, they have to be evaluated for crashworthiness and energy absorption. This has prompted Florida Department of Transportation (FDOT) to fund research for the safety evaluation of Paratransit busses consisting of crash and safety analysis. There has been a large body of research done on steel subjected to static loads, but more research is needed for steel applied under dynamic loading and high speeds in order to improve crashworthiness in events such as rollovers and side impacts. Bare steel Hollow Structural Section (HSS) tubing are used a lot as structural members of Paratransit buses because of their lightness and progressive buckling under loading. The research will be conducted on quantifying the tubing's behavior under bending by conducting static three point bending and impact loading tests. In addition to the bare tubing, plywood and fiberglass composites are investigated because they are both strong and lightweight and their behavior under dynamic loading hasn't been quantified. As a result, the main purpose of this research is to quantify the differences between the dynamic and static behavior of plywood steel composite and fiberglass steel composite tubing and compare these findings with those of bare steel tubing. The differences will be quantified using detailed and thorough experiments that will examine the composites behavior under both static and dynamic loading. These tests will determine if there are any advantages of using the composite materials and thus allow for recommendations to be made to the FDOT with the goal of improving the safety of Paratransit busses. Tensile tests were conducted to determine the material properties of the tested specimens. Before the static and dynamic experiments are run to investigate the differences between static and dynamic behavior, Preliminary three point bending testing was conducted to determine the parameters for the final experiments. Static bending testing was conducted on the bare, plywood composite, and fiberglass composite steel tubing. The point of these experiments was to produce a Moment vs. Rotation plot to determine the specimens' maximum moments and their associated rotation, as that is when the steel buckles and fails. The dynamic three point bending experiments were conducted using the impact loading apparatus and had the same purpose as the static experiments. For both static and dynamic experiments, the performances of the different types of specimens were compared based upon their Moment vs. Rotation plots. This will determine the effect that the composite has on the rotation and maximum moment at which the tubing fails. After conducting these experiments, amplification factors were established for each specimen by comparing the maximum moment and their associated rotation between static and dynamic testing. lambda was calculated to quantify the ratio between the static and dynamic maximum moments. beta was used to quantify the ratio between the rotation needed to produce the maximum moment between static and dynamic events. A small amplification factor denotes that material performs well under impact loading and the material doesn't experience dramatic change in behavior during dynamic events. Amplification factors were compared between the bare, plywood, and fiberglass composite steel tubing in order to evaluate the performance of the composites. After comparing the amplification factors of the different types of tubing, recommendations can be made. Fiberglass and plywood composite were shown to be valuable because it decreased the effect of dynamic forces as beta was reduced by a factor of 2 in comparison to bare tubing. Based upon the amplification factors, it was recommended to use 14 gauge fiberglass composite tubing as Paratransit bus structural members because it was affected the least by dynamic loading.

Factors affecting the strength of multipass low-alloy steel weld metal

NASA Technical Reports Server (NTRS)

Krantz, B. M.

1972-01-01

The mechanical properties of multipass high-strength steel weld metals depend upon several factors, among the most important being: (1) The interaction between the alloy composition and weld metal cooling rate which determines the as-deposited microstructure; and (2) the thermal effects of subsequent passes on each underlying pass which alter the original microstructure. The bulk properties of a multipass weld are therefore governed by both the initial microstructure of each weld pass and its subsequent thermal history. Data obtained for a high strength low alloy steel weld metal confirmed that a simple correlation exists between mechanical properties and welding conditions if the latter are in turn correlated as weld cooling rate.

Flood regime as a driver of the distribution of mangrove and salt marsh species in a subtropical estuary

NASA Astrophysics Data System (ADS)

Spier, Daphne; Gerum, Humberto L. N.; Noernberg, Maurício A.; Lana, Paulo C.

2016-09-01

Tidal patterns of the subtropical Paranaguá Estuarine Complex, in southern Brazil, are strongly affected by episodic cold fronts and by the coastal geometry and bottom topography, resulting in high temporal variability and marked gradients in flood regime. We delimit tolerance ranges of submersion and exposure for representative plant and animal species from local mangroves and salt marshes, through a quantitative analysis of flooding patterns in three estuarine sectors. Our results are consistent with flood regime being the leading factor on how species are distributed over the intertidal flats of the PEC. Subleading factors might be related to salinity, sediment composition and nutrient flow.

Physical Chemistry of Bile: Detailed Pathogenesis of Cholelithiasis.

PubMed

Itani, Malak; Dubinsky, Theodore J

2017-09-01

Despite the overwhelming prevalence of cholelithiasis, many health care professionals are not familiar with the basic pathophysiology of gallstone formation. This article provides an overview of the biochemical pathways related to bile, with a focus on the physical chemistry of bile. We describe the important factors in bile synthesis and secretion that affect the composition of bile and consequently its liquid state. Within this biochemical background lies the foundation for understanding the clinical and sonographic manifestation of cholelithiasis, including the pathophysiology of cholesterol crystallization, gallbladder sludge, and gallstones. There is a brief discussion of the clinical manifestations of inflammatory and obstructive cholestasis and the impact on bile metabolism and subsequently on liver function tests. Despite being the key modality in diagnosing cholelithiasis, ultrasound has a limited role in the characterization of stone composition.

Quantitative Aspects of Communicative Impairment Ascertained in a Large National Survey of Japanese Children.

PubMed

Oi, Manabu; Fujino, Hiroshi; Tsukidate, Naotake; Kamio, Yoko; Yoshimura, Yuko; Kikuchi, Mitsuru; Hasegawa, Chiaki; Gondou, Keiko; Matsui, Tomoko

2017-10-01

The Japanese version of the Children's Communication Checklist-2 (CCC-2) was rated by caregivers in a large national population sample of 22,871 children aged 3-15 years. The General Communication Composite (GCC) of the CCC-2 exhibited a distribution with a single-factor structure. The GCC distribution between autism spectrum disorders (ASD) and language impairment (LI) groups in the general population fit inside a bell curve with significant overlap with the general population, and a continuum was evident between groups. No evidence of a natural cutoff that would differentiate categorically affected from unaffected children was seen. The Social Interaction Deviance Composite (SIDC) supported the notion that ASD and LI are on the opposite endpoints of a SIDC continuum of communication impairment.

Echinacea plants as antioxidant and antibacterial agents: From traditional medicine to biotechnological applications.

PubMed

Sharifi-Rad, Mehdi; Mnayer, Dima; Morais-Braga, Maria Flaviana Bezerra; Carneiro, Joara Nályda Pereira; Bezerra, Camila Fonseca; Coutinho, Henrique Douglas Melo; Salehi, Bahare; Martorell, Miquel; Del Mar Contreras, María; Soltani-Nejad, Azam; Uribe, Yoshie Adriana Hata; Yousaf, Zubaida; Iriti, Marcello; Sharifi-Rad, Javad

2018-05-10

The genus Echinacea consists of 11 taxa of herbaceous and perennial flowering plants. In particular, Echinacea purpurea (L.) Moench is widely cultivated all over the United States, Canada, and in Europe, exclusively in Germany, for its beauty and reported medicinal properties. Echinacea extracts have been used traditionally as wound healing to improve the immune system and to treat respiratory symptoms caused by bacterial infections. Echinacea extracts have demonstrated antioxidant and antimicrobial activities, and to be safe. This survey aims at reviewing the medicinal properties of Echinacea species, their cultivation, chemical composition, and the potential uses of these plants as antioxidant and antibacterial agents in foods and in a clinical context. Moreover, the factors affecting the chemical composition of Echinacea spp. are also covered. Copyright © 2018 John Wiley & Sons, Ltd.

Influence of viscosity and amine content on C==C conversion and color stability of experimental composites.

PubMed

Camargo, Fernanda Missio; Della Bona, Álvaro; Moraes, R R; Coutinho de Souza, C R; Schneider, Luis Felipe

2015-05-01

To investigate the influence of camphorquinone (CQ):amine ratio on the degree of CC conversion (DC) and color stability of experimental dental composites formulated with different co-monomer viscosities, indirectly determined by variations in the co-monomer ratios. Experimental composites were formulated in two different BisGMA:TEGDMA molar ratios (50:50 and 70:30). Viscosities were assessed with a viscometer. For each composite formulation, four different CQ:amine ratios were added: 1:1, 1:2, 1:3 or 1:4 mol%. Materials were loaded with 40 wt% of silanized glass particles. DC was determined by Fourier-transformed infrared spectroscopy with attenuated reflectance mode (ATR-FTIR). A spectrophotometer was used to measure the CIE L*a*b* color coordinates 24h after polymerization and after 2 months stored in water. Color changes (ΔE) were calculated. Data were statistically analyzed using analyses of variance (ANOVA), Tukey's and Student-t tests (α=0.05). The 50:50 BisGMA:TEGDMA co-monomer showed lower viscosity than 70:30. DC was affected by CQ:amine ratio, and not by the co-monomer viscosity, but the interaction between these two factors was significant. a* and b* coordinates were dependent on CQ:amine or BisGMA:TEGDMA ratios, while L* was not. b* values were directly related to the amount of amine in the formulation, regardless of co-monomer viscosity. ΔE was dependent on the amount of amine, but not on the viscosity of the material. DC was influenced by the CQ:amine ratio. The influence of viscosity on DC was dependent on the CQ:amine ratio and exhibited distinguished behavior. a* and b* coordinates were affected by CQ:amine and BisGMA:TEGDMA ratios. The color change (ΔE) was affected by CQ:amine ratio, but not by viscosity. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

High hydrostatic pressure inactivation of Lactobacillus plantarum cells in (O/W)-emulsions is independent from cell surface hydrophobicity and lipid phase parameters

NASA Astrophysics Data System (ADS)

Kafka, T. A.; Reitermayer, D.; Lenz, C. A.; Vogel, R. F.

2017-07-01

Inactivation efficiency of high hydrostatic pressure (HHP) processing of food is strongly affected by food matrix composition. We investigated effects of fat on HHP inactivation of spoilage-associated Lactobacillus (L.) plantarum strains using defined oil-in-water (O/W)-emulsion model systems. Since fat-mediated effects on HHP inactivation could be dependent on interactions between lipid phase and microbial cells, three major factors possibly influencing such interactions were considered, that is, cell surface hydrophobicity, presence and type of surfactants, and oil droplet size. Pressure tolerance varied noticeably among L. plantarum strains and was independent of cell surface hydrophobicity. We showed that HHP inactivation of all strains tended to be more effective in presence of fat. The observation in both, surfactant-stabilized and surfactant-free (O/W)-emulsion, indicates that cell surface hydrophobicity is no intrinsic pressure resistance factor. In contrast to the presence of fat per se, surfactant type and oil droplet size did not affect inactivation efficiency.

Individual, group, and environmental influences on helping behavior in a social carnivore

USGS Publications Warehouse

Ausband, David E.; Mitchell, Michael S.; Bassing, Sarah B.; Morehouse, Andrea T.; Smith, Douglas W.; Stahler, Daniel R.; Struthers, Jennifer

2016-01-01

Variation in group composition and environment can affect helping behavior in cooperative breeders. Understanding of how group size, traits of individuals within groups, food abundance, and predation risk simultaneously influence helping behavior is limited. We evaluated pup-guarding behavior in gray wolves (Canis lupus) to assess how differences in individuals, groups, and environment affect helping behavior. We used data from 92 GPS-collared wolves in North America (2001–2012) to estimate individual pup-guarding rates. Individuals in groups with low helper-to-pup ratios spent more time guarding young than those in groups with more helpers, an indication of load-lightening. Female helpers guarded more than male helpers, but this relationship weakened as pups grew. Subset analyses including data on helper age and wolf and prey density showed such factors did not significantly influence pup-guarding rates. We show that characteristics of individuals and groups have strong influences on pup-guarding behavior in gray wolves, but environmental factors such as food abundance and predation risk from conspecifics were not influential.

A Bayesian compound stochastic process for modeling nonstationary and nonhomogeneous sequence evolution.

PubMed

Blanquart, Samuel; Lartillot, Nicolas

2006-11-01

Variations of nucleotidic composition affect phylogenetic inference conducted under stationary models of evolution. In particular, they may cause unrelated taxa sharing similar base composition to be grouped together in the resulting phylogeny. To address this problem, we developed a nonstationary and nonhomogeneous model accounting for compositional biases. Unlike previous nonstationary models, which are branchwise, that is, assume that base composition only changes at the nodes of the tree, in our model, the process of compositional drift is totally uncoupled from the speciation events. In addition, the total number of events of compositional drift distributed across the tree is directly inferred from the data. We implemented the method in a Bayesian framework, relying on Markov Chain Monte Carlo algorithms, and applied it to several nucleotidic data sets. In most cases, the stationarity assumption was rejected in favor of our nonstationary model. In addition, we show that our method is able to resolve a well-known artifact. By Bayes factor evaluation, we compared our model with 2 previously developed nonstationary models. We show that the coupling between speciations and compositional shifts inherent to branchwise models may lead to an overparameterization, resulting in a lesser fit. In some cases, this leads to incorrect conclusions, concerning the nature of the compositional biases. In contrast, our compound model more flexibly adapts its effective number of parameters to the data sets under investigation. Altogether, our results show that accounting for nonstationary sequence evolution may require more elaborate and more flexible models than those currently used.

Cultivar Diversity of Grape Skin Polyphenol Composition and Changes in Response to Drought Investigated by LC-MS Based Metabolomics

PubMed Central

Pinasseau, Lucie; Vallverdú-Queralt, Anna; Verbaere, Arnaud; Roques, Maryline; Meudec, Emmanuelle; Le Cunff, Loïc; Péros, Jean-Pierre; Ageorges, Agnès; Sommerer, Nicolas; Boulet, Jean-Claude; Terrier, Nancy; Cheynier, Véronique

2017-01-01

Phenolic compounds represent a large family of plant secondary metabolites, essential for the quality of grape and wine and playing a major role in plant defense against biotic and abiotic stresses. Phenolic composition is genetically driven and greatly affected by environmental factors, including water stress. A major challenge for breeding of grapevine cultivars adapted to climate change and with high potential for wine-making is to dissect the complex plant metabolic response involved in adaptation mechanisms. A targeted metabolomics approach based on ultra high-performance liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-QqQ-MS) analysis in the Multiple Reaction Monitoring (MRM) mode has been developed for high throughput profiling of the phenolic composition of grape skins. This method enables rapid, selective, and sensitive quantification of 96 phenolic compounds (anthocyanins, phenolic acids, stilbenoids, flavonols, dihydroflavonols, flavan-3-ol monomers, and oligomers…), and of the constitutive units of proanthocyanidins (i.e., condensed tannins), giving access to detailed polyphenol composition. It was applied on the skins of mature grape berries from a core-collection of 279 Vitis vinifera cultivars grown with or without watering to assess the genetic variation for polyphenol composition and its modulation by irrigation, in two successive vintages (2014–2015). Distribution of berry weights and δ13C values showed that non irrigated vines were subjected to a marked water stress in 2014 and to a very limited one in 2015. Metabolomics analysis of the polyphenol composition and chemometrics analysis of this data demonstrated an influence of water stress on the biosynthesis of different polyphenol classes and cultivar differences in metabolic response to water deficit. Correlation networks gave insight on the relationships between the different polyphenol metabolites and related biosynthetic pathways. They also established patterns of polyphenol response to drought, with different molecular families affected either positively or negatively in the different cultivars, with potential impact on grape and wine quality. PMID:29163566

The First Microbial Colonizers of the Human Gut: Composition, Activities, and Health Implications of the Infant Gut Microbiota.

PubMed

Milani, Christian; Duranti, Sabrina; Bottacini, Francesca; Casey, Eoghan; Turroni, Francesca; Mahony, Jennifer; Belzer, Clara; Delgado Palacio, Susana; Arboleya Montes, Silvia; Mancabelli, Leonardo; Lugli, Gabriele Andrea; Rodriguez, Juan Miguel; Bode, Lars; de Vos, Willem; Gueimonde, Miguel; Margolles, Abelardo; van Sinderen, Douwe; Ventura, Marco

2017-12-01

The human gut microbiota is engaged in multiple interactions affecting host health during the host's entire life span. Microbes colonize the neonatal gut immediately following birth. The establishment and interactive development of this early gut microbiota are believed to be (at least partially) driven and modulated by specific compounds present in human milk. It has been shown that certain genomes of infant gut commensals, in particular those of bifidobacterial species, are genetically adapted to utilize specific glycans of this human secretory fluid, thus representing a very intriguing example of host-microbe coevolution, where both partners are believed to benefit. In recent years, various metagenomic studies have tried to dissect the composition and functionality of the infant gut microbiome and to explore the distribution across the different ecological niches of the infant gut biogeography of the corresponding microbial consortia, including those corresponding to bacteria and viruses, in healthy and ill subjects. Such analyses have linked certain features of the microbiota/microbiome, such as reduced diversity or aberrant composition, to intestinal illnesses in infants or disease states that are manifested at later stages of life, including asthma, inflammatory bowel disease, and metabolic disorders. Thus, a growing number of studies have reported on how the early human gut microbiota composition/development may affect risk factors related to adult health conditions. This concept has fueled the development of strategies to shape the infant microbiota composition based on various functional food products. In this review, we describe the infant microbiota, the mechanisms that drive its establishment and composition, and how microbial consortia may be molded by natural or artificial interventions. Finally, we discuss the relevance of key microbial players of the infant gut microbiota, in particular bifidobacteria, with respect to their role in health and disease. Copyright © 2017 American Society for Microbiology.

Do dry roasting, lightly salting nuts affect their cardioprotective properties and acceptability?

PubMed

Tey, Siew Ling; Robinson, Terryn; Gray, Andrew R; Chisholm, Alexandra W; Brown, Rachel Clare

2017-04-01

Previous studies have reported improvements in cardiovascular disease (CVD) risk factors with the consumption of raw nuts. However, around one-third of nuts consumed are roasted and salted. Thus, it is important to determine whether roasting and salting nuts affect the health benefits observed with raw nuts. This study aimed to compare the effects of consuming two different forms of hazelnuts on cardiovascular risk factors and acceptance. Using a randomised crossover design, 72 participants were asked to consume 30 g/day of either raw or dry roasted, lightly salted hazelnuts for 28 days each. CVD risk factors were measured at the beginning and end of each treatment period. "Desire to consume" and "overall liking" for both forms of hazelnuts were assessed daily using a 150-mm visual analogue scale. Body composition, blood pressure, plasma total and low-density lipoprotein-cholesterol, apolipoprotein A1 and B100, glucose and α-tocopherol concentrations did not differ between forms of hazelnuts (all P ≥ 0.054). High-density lipoprotein (HDL)-cholesterol (P = 0.037) and triacylglycerol (P < 0.001) concentrations were significantly lower following the consumption of dry roasted, lightly salted hazelnuts when compared to the raw hazelnuts. Compared with baseline, consuming both forms of hazelnuts significantly improved HDL-cholesterol and apolipoprotein A1 concentrations, total-C/HDL-C ratio, and systolic blood pressure without significantly changing body composition. Acceptance ratings did not differ between forms of hazelnuts and remained high throughout the study. Dry roasting and lightly salting nuts do not appear to negate the cardioprotective effects observed with raw nut consumption, and both forms of nuts are resistant to monotony. Public health messages could be extended to include dry roasted and lightly salted nuts as part of a heart healthy diet.

Interactions between extracellular polymeric substances and clay minerals affect soil aggregation

NASA Astrophysics Data System (ADS)

Vogel, Cordula; Rehschuh, Stephanie; Kemi Olagoke, Folasade; Redmile Gordon, Marc; Kalbiltz, Karsten

2017-04-01

Soil aggregation is crucial for carbon (C) sequestration and microbial processes have been recognised as important control of aggregate turnover (formation, stability, and destruction). However, how microorganisms contribute to these processes is still a matter of debate. An enthralling mechanism determining aggregate turnover and therefore C sequestration may be the excretion of extracellular polymeric substances (EPS) as microbial glue, but effects of EPS on aggregation is largely unknown. Moreover, interdependencies between important aggregation factors like the amount of fine-sized particles (clay content), the decomposability of organic matter and the microbial community (size and composition, as well as the excretion of EPS) are still poorly understood. Therefore, we studied the complex interactions between these factors and their role in aggregate turnover. It was hypothesized that an increase in microbial activity, induced by the input of organic substrates, will stimulate EPS production and therefore the formation and stability of aggregates. To test this hypothesis, an incubation experiment has been conducted across a gradient of clay content (montmorillonite) and substrate decomposability (starch and glucose) as main drivers of the microbial activity. A combination of aggregate separation and stability tests were applied. This results will be examined with respect to the obtained microbial parameters (amount and composition of EPS, CO2 emission, microbial biomass, phospholipid fatty acid), to disentangle the mechanisms and factors controlling aggregate turnover affected by soil microorganisms. This study is expected to provide insights on the role of EPS in the stability of aggregates. Thus, the results of this study will provide an improved understanding of the underlying processes of aggregate turnover in soils, which is necessary to implement strategies for enhanced C sequestration in agricultural soils.

Factors affecting chick provisioning by Caspian Terns nesting in the Columbia River estuary

USGS Publications Warehouse

Anderson, Scott K.; Roby, D.D.; Lyons, Donald E.; Collis, K.

2005-01-01

We investigated factors affecting chick provisioning by radio-tagged Caspian Terns (Sterna caspia) nesting in a large colony on East Sand Island in the Columbia River estuary during 2001. Caspian Tern predation on juvenile salmonids (Oncorhynchus spp.) in the estuary prompted resource managers to relocate ca. 9,000 pairs of terns nesting on Rice Island (river km 34) to East Sand Island (river km 8), where terns were expected to consume fewer salmonids in favor of marine forage fishes. This study investigated factors influencing foraging success, diet composition, and overall reproductive success at the managed Caspian Tern colony. Our results indicated that daytime colony attendance by nesting terns averaged 64% and decreased throughout the chick-rearing period, while duration of foraging trips averaged 47 min and increased during the same period; these seasonal changes were more strongly related to date than chick age. Average meal delivery rates to 2-chick broods (0.88 meals h-1) were 2.6 times greater than to 1-chick broods (0.33 meals h-1). Parents delivered more juvenile salmonids to chicks during ebb tides than flood tides, but meal delivery rates to the nest remained constant, suggesting diet composition tracks relative availability of prey species. Foraging trips resulting in delivery of juvenile salmonids averaged 68% longer than foraging trips for schooling marine forage fishes, indicating higher availability of marine prey near the colony. High availability of marine forage fish in the Columbia River estuary during 2001 was apparently responsible for high colony attendance, short foraging trips, high chick meal delivery rates, and high nesting success of Caspian Terns on East Sand Island.

Human, donkey and cow milk differently affects energy efficiency and inflammatory state by modulating mitochondrial function and gut microbiota.

PubMed

Trinchese, Giovanna; Cavaliere, Gina; Canani, Roberto Berni; Matamoros, Sebastien; Bergamo, Paolo; De Filippo, Chiara; Aceto, Serena; Gaita, Marcello; Cerino, Pellegrino; Negri, Rossella; Greco, Luigi; Cani, Patrice D; Mollica, Maria Pina

2015-11-01

Different nutritional components are able, by modulating mitochondrial function and gut microbiota composition, to influence body composition, metabolic homeostasis and inflammatory state. In this study, we aimed to evaluate the effects produced by the supplementation of different milks on energy balance, inflammatory state, oxidative stress and antioxidant/detoxifying enzyme activities and to investigate the role of the mitochondrial efficiency and the gut microbiota in the regulation of metabolic functions in an animal model. We compared the intake of human milk, gold standard for infant nutrition, with equicaloric supplementation of donkey milk, the best substitute for newborns due to its nutritional properties, and cow milk, the primary marketed product. The results showed a hypolipidemic effect produced by donkey and human milk intake in parallel with enhanced mitochondrial activity/proton leakage. Reduced mitochondrial energy efficiency and proinflammatory signals (tumor necrosis factor α, interleukin-1 and lipopolysaccharide levels) were associated with a significant increase of antioxidants (total thiols) and detoxifying enzyme activities (glutathione-S-transferase, NADH quinone oxidoreductase) in donkey- and human milk-treated animals. The beneficial effects were attributable, at least in part, to the activation of the nuclear factor erythroid-2-related factor-2 pathway. Moreover, the metabolic benefits induced by human and donkey milk may be related to the modulation of gut microbiota. In fact, milk treatments uniquely affected the proportions of bacterial phyla and genera, and we hypothesized that the increased concentration of fecal butyrate in human and donkey milk-treated rats was related to the improved lipid and glucose metabolism and detoxifying activities. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Mantle viscosity structure constrained by joint inversions of seismic velocities and density

NASA Astrophysics Data System (ADS)

Rudolph, M. L.; Moulik, P.; Lekic, V.

2017-12-01

The viscosity structure of Earth's deep mantle affects the thermal evolution of Earth, the ascent of mantle upwellings, sinking of subducted oceanic lithosphere, and the mixing of compositional heterogeneities in the mantle. Modeling the long-wavelength dynamic geoid allows us to constrain the radial viscosity profile of the mantle. Typically, in inversions for the mantle viscosity structure, wavespeed variations are mapped into density variations using a constant- or depth-dependent scaling factor. Here, we use a newly developed joint model of anisotropic Vs, Vp, density and transition zone topographies to generate a suite of solutions for the mantle viscosity structure directly from the seismologically constrained density structure. The density structure used to drive our forward models includes contributions from both thermal and compositional variations, including important contributions from compositionally dense material in the Large Low Velocity Provinces at the base of the mantle. These compositional variations have been neglected in the forward models used in most previous inversions and have the potential to significantly affect large-scale flow and thus the inferred viscosity structure. We use a transdimensional, hierarchical, Bayesian approach to solve the inverse problem, and our solutions for viscosity structure include an increase in viscosity below the base of the transition zone, in the shallow lower mantle. Using geoid dynamic response functions and an analysis of the correlation between the observed geoid and mantle structure, we demonstrate the underlying reason for this inference. Finally, we present a new family of solutions in which the data uncertainty is accounted for using covariance matrices associated with the mantle structure models.

Does the Lagoa do peixe sandbar opening influence the macrophyte richness and composition in Southern Brazil wetlands?

PubMed

Rolon, Ana Silvia; Rocha, Odete; Maltchik, Leonardo

2013-03-01

The Lagoa do Peixe has its connection with the sea artificially opened every year at the end of winter. However, this management has been carried out without the evaluation of the impact of this opening in the aquatic biodiversity. This information is crucial for the management of the natural resources of the Lagoa do Peixe National Park, the unique Ramsar site in Southern Brazil. The following questions were analyzed: (1) Do richness and composition of aquatic macrophytes from Lagoa do Peixe floodplain varies temporarily according to the sandbar opening and closing? (2) Does the variation pattern of the macrophyte community changed according to the sandbar opening and closing? A set of eight sampling sites of 1ha were selected over the Lagoa do Peixe floodplain: four sites not influenced by the artificial sandbar opening and four sites influenced by this event, being two sites closer to the sandbar opening and the two sites distant to the sandbar opening. The samplings were carried out between November 2007 and October 2009. The results show that although the artificial sandbar breaching does not affect the aquatic macrophyte richness at the floodplain, it affects the dynamics of species composition. The hydrological variation related to this management can be the main factor of the continuous change in the species composition in the floodplain, especially in the Southern portion. In order to avoid impacts in the macrophyte conservation, the artificial sandbar opening should be considered carefully, since the area of study is one of the most important conservation units to wetland systems in Southern Brazil.

Disentangling factors that control the vulnerability of forests to catastrophic wind damage

NASA Astrophysics Data System (ADS)

Dracup, E.; Taylor, A.; MacLean, D.; Boulanger, Y.

2017-12-01

Wind is an important driver of forest dynamics along North America's north-eastern coastal forests, but also damages many commercially managed forests which society relies as an important source of wood fiber. Although the influence of wind on north-eastern forests is well recognized, knowledge of factors predisposing trees to wind damage is less known, especially in the context of large, powerful wind storm events. This is of particular concern as climate change is expected to alter the frequency and severity of strong wind storms affecting this region. On 29 September 2003, Hurricane Juan made landfall over Nova Scotia, Canada as a Category 2 hurricane with sustained winds of 158 km/h, and gusts of up to 185 km/h. Hurricane Juan variously damaged a swath of over 600,000 ha of forest. The damaged forest area was surveyed using aerial photography and LandSAT imagery and categorized according to level of wind damage sustained (none, low, moderate, severe) at a resolution of 15 x 15 m square cells. We used Random Forest to analyze and compare level of wind damage in each cell with a myriad of abiotic (exposure, depth to water table, soil composition, etc.) and biotic (tree species composition, canopy closure, canopy height, etc.) factors known or expected to predispose trees to windthrow. From our analysis, we identified topographic exposure, precipitation, and maximum gust speed as the top predictors of windthrow during Hurricane Juan. To our surprise, forest stand factors, such as tree species composition and height, had minimal effects on level of windthrow. These results can be used to construct predictive risk maps which can help society to assess the vulnerability of forests to future wind storm events.

Composition of growth factors and cytokines in lysates obtained from fresh versus stored pathogen-inactivated platelet units.

PubMed

Sellberg, Felix; Berglund, Erik; Ronaghi, Martin; Strandberg, Gabriel; Löf, Helena; Sommar, Pehr; Lubenow, Norbert; Knutson, Folke; Berglund, David

2016-12-01

Platelet lysate is a readily available source of growth factors, and other mediators, which has been used in a variety of clinical applications. However, the product remains poorly standardized and the present investigation evaluates the composition of platelet lysate obtained from either fresh or stored pathogen-inactivated platelet units. Platelet pooled units (n = 10) were obtained from healthy blood donors and tested according to standard procedures. All units were pathogen inactivated using amotosalen hydrochloride and UVA exposure. Platelet lysate was subsequently produced at two separate time-points, either from fresh platelet units or after 5 days of storage, by repeated freeze-thaw cycles. The following mediators were determined at each time-point: EGF, FGF-2, VEGF, IGF-1, PDGF-AB/BB, BMP-2, PF4, TGF-β isoform 1, IL-1β, IL-2, IL-6, IL-10, IL-12p70, 1L-17A, TNF-α, and IFN-γ. The concentration of growth factors and cytokines was affected by time in storage. Notably, TGF-β, PDGF-AB/BB, and PF4 showed an increase of 27.2% (p < 0.0001), 29.5% (p = 0.04) and 8.2% (p = 0.0004), respectively. A decrease was seen in the levels of IGF-1 and FGF-2 with 22% (p = 0.041) and 11% (p = 0.01), respectively. Cytokines were present only in very low concentrations and all other growth factors remained stable with time in storage. The composition of mediators in platelet lysate obtained from pathogen-inactivated platelet units differs when produced from fresh and stored platelet units, respectively. This underscores the need for further standardization and optimization of this important product, which potentially may influence the clinical effects. Copyright © 2016. Published by Elsevier Ltd.

Prenatal physical activity and diet composition affect the expression of nutrient transporters and mTOR signaling molecules in the human placenta.

PubMed

Brett, K E; Ferraro, Z M; Holcik, M; Adamo, K B

2015-02-01

Adequate nutrient delivery to the fetus is essential for optimal growth. Differences in prenatal physical activity level and diet quality influence maternal energy balance and these factors may alter placental nutrient transport. We investigated the associations between meeting physical activity guidelines and the quality of maternal diet on the expression of genes involved in fatty acid, amino acid and glucose transport, and mammalian target of rapamycin (mTOR) and insulin signaling in the placenta from 16 term pregnancies. Physical activity was directly measured with accelerometry, diet composition was assessed with 24 h dietary recalls, and gene expression was measured with custom polymerase chain reaction (PCR) arrays. Women who met physical activity guidelines had lower gene expression of fatty acid transport protein 4 (FATP4), insulin-like growth factor 1 (IGF1), and the beta non-catalytic subunit of AMP-activated protein kinase (AMPK), and a higher expression of SNAT2. There was a strong positive correlation observed between total sugar intake and glucose transporter 1 (GLUT1) (r = 0.897, p = 0.000, n = 12), and inverse correlations between total sugar and mTOR and IGF1 expression. Percentage of total calories from protein was inversely related to insulin-like growth factor 1 receptor (IGF1R) (r = -0.605, p = 0.028, n = 13). Variations in maternal physical activity and diet composition altered the expression of genes involved in fatty acid, amino acid and glucose transport and mTOR signaling. Future research on placental nutrient transport should include direct measures of maternal PA and dietary habits to help eliminate confounding factors. Copyright © 2014 Elsevier Ltd. All rights reserved.

Delamination measurement of a laminates composite panel due to hole punching based on the focus variation technique

NASA Astrophysics Data System (ADS)

Abdullah, A. B.; Zain, M. S. M.; Abdullah, M. S.; Samad, Z.

2017-07-01

Structural materials, such as composite panels, must be assembled, and such panels are typically constructed via the insertion of a fastener through a drilled hole. The main problem encountered in drilling is delamination, which affects assembly strength. The cost of drilling is also high because of the severe wear on drill bits. The main goal of this research is to develop a new punching method as an alternative to drilling during hole preparation. In this study, the main objective is to investigate the effect of different puncher profiles on the quality of holes punched into carbon fiber reinforcement polymer (CFRP) composite panels. Six types of puncher profiles were fabricated with minimum die clearance (1%), and two quality aspects, namely, incomplete shearing and delamination factor, were measured. The conical puncher incurred the least defects in terms of delamination and yielded an acceptable amount of incomplete shearing in comparison with the other punchers.

Black carbon absorption at the global scale is affected by particle-scale diversity in composition.

PubMed

Fierce, Laura; Bond, Tami C; Bauer, Susanne E; Mena, Francisco; Riemer, Nicole

2016-09-01

Atmospheric black carbon (BC) exerts a strong, but uncertain, warming effect on the climate. BC that is coated with non-absorbing material absorbs more strongly than the same amount of BC in an uncoated particle, but the magnitude of this absorption enhancement (Eabs) is not well constrained. Modelling studies and laboratory measurements have found stronger absorption enhancement than has been observed in the atmosphere. Here, using a particle-resolved aerosol model to simulate diverse BC populations, we show that absorption is overestimated by as much as a factor of two if diversity is neglected and population-averaged composition is assumed across all BC-containing particles. If, instead, composition diversity is resolved, we find Eabs=1-1.5 at low relative humidity, consistent with ambient observations. This study offers not only an explanation for the discrepancy between modelled and observed absorption enhancement, but also demonstrates how particle-scale simulations can be used to develop relationships for global-scale models.

Fruit position within the canopy affects kernel lipid composition of hazelnuts.

PubMed

Pannico, Antonio; Cirillo, Chiara; Giaccone, Matteo; Scognamiglio, Pasquale; Romano, Raffaele; Caporaso, Nicola; Sacchi, Raffaele; Basile, Boris

2017-11-01

The aim of this research was to study the variability in kernel composition within the canopy of hazelnut trees. Kernel fresh and dry weight increased linearly with fruit height above the ground. Fat content decreased, while protein and ash content increased, from the bottom to the top layers of the canopy. The level of unsaturation of fatty acids decreased from the bottom to the top of the canopy. Thus, the kernels located in the bottom layers of the canopy appear to be more interesting from a nutritional point of view, but their lipids may be more exposed to oxidation. The content of different phytosterols increased progressively from bottom to top canopy layers. Most of these effects correlated with the pattern in light distribution inside the canopy. The results of this study indicate that fruit position within the canopy is an important factor in determining hazelnut kernel growth and composition. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Black Carbon Absorption at the Global Scale Is Affected by Particle-Scale Diversity in Composition

NASA Technical Reports Server (NTRS)

Fierce, Laura; Bond, Tami C.; Bauer, Susanne E.; Mena, Francisco; Riemer, Nicole

2016-01-01

Atmospheric black carbon (BC) exerts a strong, but uncertain, warming effect on the climate. BC that is coated with non-absorbing material absorbs more strongly than the same amount of BC in an uncoated particle, but the magnitude of this absorption enhancement (E(sub abs)) is not well constrained. Modelling studies and laboratory measurements have found stronger absorption enhancement than has been observed in the atmosphere. Here, using a particle-resolved aerosol model to simulate diverse BC populations, we show that absorption is overestimated by as much as a factor of two if diversity is neglected and population-averaged composition is assumed across all BC-containing particles. If, instead, composition diversity is resolved, we find E(sub abs) = 1 - 1.5 at low relative humidity, consistent with ambient observations. This study offers not only an explanation for the discrepancy between modelled and observed absorption enhancement, but also demonstrates how particle-scale simulations can be used to develop relationships for global-scale models.

Two-Ply Composite Membranes with Separation Layers from Chitosan and Sulfoethylcellulose on a Microporous Support Based on Poly(diphenylsulfone-N-phenylphthalimide).

PubMed

Kononova, Svetlana V; Kruchinina, Elena V; Petrova, Valentina A; Baklagina, Yulia G; Romashkova, Kira A; Orekhov, Anton S; Klechkovskaya, Vera V; Skorik, Yury A

2017-12-14

Two-ply composite membranes with separation layers from chitosan and sulfoethylcellulose were developed on a microporous support based on poly(diphenylsulfone- N -phenylphthalimide) and investigated by use of X-ray diffraction and scanning electron microscopy methods. The pervaporation properties of the membranes were studied for the separation of aqueous alcohol (ethanol, propan-2-ol) mixtures of different compositions. When the mixtures to be separated consist of less than 15 wt % water in propan-2-ol, the membranes composed of polyelectrolytes with the same molar fraction of ionogenic groups (-NH₃⁺ for chitosan and -SO₃ - for sulfoethylcellulose) show high permselectivity (the water content in the permeate was 100%). Factors affecting the structure of a non-porous layer of the polyelectrolyte complex formed on the substrate surface and the contribution of that complex to changes in the transport properties of membranes are discussed. The results indicate significant prospects for the use of chitosan and sulfoethylcellulose for the formation of highly selective pervaporation membranes.

The Effect of Ionic Liquid Pretreatment on the Bioconversion of Tomato Processing Waste to Fermentable Sugars and Biogas.

PubMed

Allison, Brittany J; Cádiz, Juan Canales; Karuna, Nardrapee; Jeoh, Tina; Simmons, Christopher W

2016-08-01

Tomato pomace is an abundant lignocellulosic waste stream from industrial tomato processing and therefore a potential feedstock for production of renewable biofuels. However, little research has been conducted to determine if pretreatment can enhance release of fermentable sugars from tomato pomace. Ionic liquids (ILs) are an emerging pretreatment technology for lignocellulosic biomass to increase enzymatic digestibility and biofuel yield while utilizing recyclable chemicals with low toxicity. In this study, pretreatment of tomato pomace with the ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) was investigated. Changes in pomace enzymatic digestibility were affected by pretreatment time and temperature. Certain pretreatment conditions significantly improved reducing sugar yield and hydrolysis time compared to untreated pomace. Compositional analyses suggested that pretreatment primarily removed water-soluble compounds and enriched for lignocellulose in pomace, with only subtle changes to the composition of the lignocellulose. While tomato pomace was effectively pretreated with [C2mim][OAc] to improve enzymatic digestibility, as of yet, unknown factors in the pomace caused ionic liquid pretreatment to negatively affect anaerobic digestion of pretreated material. This result, which is unique compared to similar studies on IL pretreatment of grasses and woody biomass, highlights the need for additional research to determine how the unique chemical composition of tomato pomace and other lignocellulosic fruit residues may interact with ionic liquids to generate inhibitors for downstream fermentation to biofuels.

Field Detection of Chemical Assimilation in A Basaltic Lava Flow

NASA Technical Reports Server (NTRS)

Young, K. E.; Bleacher, J. E.; Needham, D. H.; Evans, C. A.; Whelley, P. L.; Scheidt, S. P.; Williams, D. A.; Rogers, A. D.; Glotch, T.

2017-01-01

Lava channels are features seen throughout the inner Solar System, including on Earth, the Moon, and Mars. Flow emplacement is therefore a crucial process in the shaping of planetary surfaces. Many studies, including some completed by members of this team at the December 1974 lava flow, have investigated the dynamics of lava flow emplacement, both on Earth and on the Moon and how pre-flow terrain can impact final channel morphology, but far fewer have focused on how the compositional characteristics of the substrate over which a flow was em-placed influenced its final flow morphology. Within the length of one flow, it is common for flows to change in morphology, a quality linked to rheology (a function of multiple factors including viscosi-ty, temperature, composition, etc.). The relationship between rheology and temperature has been well-studied but less is known about the relationship between an older flow's chemistry and how the interaction between this flow and the new flow might affect lava rheology and therefore emplacement dynamics. Lava erosion. Through visual observations of active terrestrial flows, mechanical erosion by flowing lava has been well-documented. Lava erosion by which flow composition is altered as the active lava melts and assimilates the pre-flow terrain over which it moves is also hypothesized to affect channel formation. However, there is only one previous field study that geochemically documents the process in recent basaltic flow systems.

Assessing transmission of crop diseases by insect vectors in a landscape context.

PubMed

Carrière, Y; Degain, B; Hartfield, K A; Nolte, K D; Marsh, S E; Ellers-Kirk, C; Van Leeuwen, W J D; Liesner, L; Dutilleul, P; Palumbo, J C

2014-02-01

Theory indicates that landscape composition affects transmission of vector-borne crop diseases, but few empirical studies have investigated how landscape composition affects plant disease epidemiology. Since 2006, Bemisia tabaci (Gennadius) has vectored the cucurbit yellow stunting disorder virus (CYSDV) to cantaloupe and honeydew melons (Cucumis melo L.) in the southwestern United States and northern Mexico, causing significant reductions in yield of fall melons and increased use of insecticides. Here, we show that a landscape-based approach allowing simultaneous assessment of impacts of local (i.e., planting date) and regional (i.e., landscape composition) factors provides valuable insights on how to reduce crop disease risks. Specifically, we found that planting fall melon fields early in the growing season, eliminating plants germinating from seeds produced by spring melons after harvest, and planting fall melon fields away from cotton and spring melon fields may significantly reduce the incidence of CYSDV infection in fall melons. Because the largest scale of significance of the positive association between abundance of cotton and spring melon fields and CYSDV incidence was 1,750 and 3,000 m, respectively, reducing areas of cotton and spring melon fields within these distances from fall melon fields may decrease CYSDV incidence. Our results indicate that landscape-based studies will be fruitful to alleviate limitations imposed on crop production by vector-borne diseases.

Host lignin composition affects haustorium induction in the parasitic plants Phtheirospermum japonicum and Striga hermonthica.

PubMed

Cui, Songkui; Wada, Syogo; Tobimatsu, Yuki; Takeda, Yuri; Saucet, Simon B; Takano, Toshiyuki; Umezawa, Toshiaki; Shirasu, Ken; Yoshida, Satoko

2018-04-01

Parasitic plants in the family Orobanchaceae are destructive weeds of agriculture worldwide. The haustorium, an essential parasitic organ used by these plants to penetrate host tissues, is induced by host-derived phenolic compounds called haustorium-inducing factors (HIFs). The origin of HIFs remains unknown, although the structures of lignin monomers resemble that of HIFs. Lignin is a natural phenylpropanoid polymer, commonly found in secondary cell walls of vascular plants. We therefore investigated the possibility that HIFs are derived from host lignin. Various lignin-related phenolics, quinones and lignin polymers, together with nonhost and host plants that have different lignin compositions, were tested for their haustorium-inducing activity in two Orobanchaceae species, a facultative parasite, Phtheirospermum japonicum, and an obligate parasite, Striga hermonthica. Lignin-related compounds induced haustoria in P. japonicum and S. hermonthica with different specificities. High concentrations of lignin polymers induced haustorium formation. Treatment with laccase, a lignin degradation enzyme, promoted haustorium formation at low concentrations. The distinct lignin compositions of the host and nonhost plants affected haustorium induction, correlating with the response of the different parasitic plants to specific types of lignin-related compounds. Our study provides valuable insights into the important roles of lignin biosynthesis and degradation in the production of HIFs. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Central body fat changes in men affected by post-surgical hypogonadotropic hypogonadism undergoing testosterone replacement therapy are modulated by androgen receptor CAG polymorphism.

PubMed

Tirabassi, G; delli Muti, N; Buldreghini, E; Lenzi, A; Balercia, G

2014-08-01

Little is known about the effect of androgen receptor (AR) gene CAG repeat polymorphism in conditioning body composition changes after testosterone replacement therapy (TRT). In this study, we aimed to clarify this aspect by focussing our attention on male post-surgical hypogonadotropic hypogonadism, a condition often associated with partial or total hypopituitarism. Fourteen men affected by post-surgical hypogonadotropic hypogonadism and undergoing several replacement hormone therapies were evaluated before and after TRT. Dual-energy X-ray absorptiometry (DEXA)-derived body composition measurements, pituitary-dependent hormones and AR gene CAG repeat polymorphism were considered. While testosterone and insulin-like growth factor-1 (IGF-1) levels increased after TRT, cortisol concentration decreased. No anthropometric or body composition parameters varied significantly, except for abdominal fat decrease. The number of CAG triplets was positively and significantly correlated with this abdominal fat decrease, while the opposite occurred between the latter and Δ-testosterone. No correlation of IGF-1 or cortisol variation (Δ-) with Δ-abdominal fat was found. At multiple linear regression, after correction for Δ-testosterone, the positive association between CAG triplet number and abdominal fat change was confirmed. In male post-surgical hypogonadotropic hypogonadism, shorter length of AR CAG repeat tract is independently associated with a more marked decrease of abdominal fat after TRT. Copyright © 2014 Elsevier B.V. All rights reserved.

Assessing local resilience to typhoon disasters: A case study in Nansha, Guangzhou.

PubMed

Song, Jinglu; Huang, Bo; Li, Rongrong

2018-01-01

Building communities' resilience to natural weather hazards requires the appropriate assessment of such capabilities. The resilience of a community is affected not only by social, economic, and infrastructural factors but also by natural factors (including both site characteristics and the intensity and frequency of events). To date, studies of natural factors have tended to draw on annual censuses and to use aggregated data, thus allowing only a limited understanding of site-specific hot or cold spots of resilience. To improve this situation, we carried out a comprehensive assessment of resilience to typhoon disasters in Nansha district, Guangzhou, China. We measured disaster resilience on 1×1-km grid units with respect to socioeconomic and infrastructural dimensions using a set of variables and also estimated natural factors in a detailed manner with a meteorological modeling tool, the Weather Research and Forecast model. We selected typhoon samples over the past 10 years, simulated the maximum typhoon-borne strong winds and precipitation of each sample, and predicted the wind speed and precipitation volume at the 100-year return-level on the basis of extreme value analysis. As a result, a composite resilience index was devised by combining factors in different domains using factor analysis coupled with the analytic hierarchy process. Resilience mapping using this composite resilience index allows local governments and planners to identify potential hot or cold spots of resilience and the dominant factors in particular locations, thereby assisting them in making more rational site-specific measures to improve local resilience to future typhoon disasters.

Assessing local resilience to typhoon disasters: A case study in Nansha, Guangzhou

PubMed Central

Huang, Bo; Li, Rongrong

2018-01-01

Building communities’ resilience to natural weather hazards requires the appropriate assessment of such capabilities. The resilience of a community is affected not only by social, economic, and infrastructural factors but also by natural factors (including both site characteristics and the intensity and frequency of events). To date, studies of natural factors have tended to draw on annual censuses and to use aggregated data, thus allowing only a limited understanding of site-specific hot or cold spots of resilience. To improve this situation, we carried out a comprehensive assessment of resilience to typhoon disasters in Nansha district, Guangzhou, China. We measured disaster resilience on 1×1-km grid units with respect to socioeconomic and infrastructural dimensions using a set of variables and also estimated natural factors in a detailed manner with a meteorological modeling tool, the Weather Research and Forecast model. We selected typhoon samples over the past 10 years, simulated the maximum typhoon-borne strong winds and precipitation of each sample, and predicted the wind speed and precipitation volume at the 100-year return-level on the basis of extreme value analysis. As a result, a composite resilience index was devised by combining factors in different domains using factor analysis coupled with the analytic hierarchy process. Resilience mapping using this composite resilience index allows local governments and planners to identify potential hot or cold spots of resilience and the dominant factors in particular locations, thereby assisting them in making more rational site-specific measures to improve local resilience to future typhoon disasters. PMID:29522526

The content of polyphenolic compounds in cocoa beans (Theobroma cacao L.), depending on variety, growing region, and processing operations: a review.

PubMed

Oracz, Joanna; Zyzelewicz, Dorota; Nebesny, Ewa

2015-01-01

Polyphenols form the largest group of compounds among natural antioxidants, which largely affect the overall antioxidant and anti-free radical activity of cocoa beans. The qualitative and quantitative composition of individual fractions of polyphenolic compounds, even within one species, is very diverse and depends on many factors, mainly on the area of cocoa trees cultivation, bean maturity, climatic conditions during growth, and the harvest season and storage time after harvest. Thermal processing of cocoa beans and cocoa derivative products at relatively high temperatures may in addition to favorable physicochemical, microbiological, and organoleptic changes result in a decrease of polyphenols concentration. Technological processing of cocoa beans negatively affects the content of polyphenolic compounds.

Longevity-modulating effects of symbiosis: insights from Drosophila-Wolbachia interaction.

PubMed

Maistrenko, Oleksandr M; Serga, Svitlana V; Vaiserman, Alexander M; Kozeretska, Iryna A

2016-11-01

Microbial communities are known to significantly affect various fitness components and survival of their insect hosts, including Drosophila. The composition of symbiotic microbiota has been shown to change with the host's aging. It is unclear whether these changes are caused by the aging process or, vice versa, they affect the host's aging and longevity. Recent findings indicate that fitness and lifespan of Drosophila are affected by endosymbiotic bacteria Wolbachia. These effects, however, are inconsistent and have been reported both to extend and shorten longevity. The main molecular pathways underlying the lifespan-modulating effects of Wolbachia remain unclear, however insulin/insulin-like growth factor, immune deficiency, ecdysteroid synthesis and signaling and c-Jun N-terminal kinase pathways as well as heat shock protein synthesis and autophagy have been proposed to play a role. Here we revise the current evidence that elucidates the impact of Wolbachia endosymbionts on the aging processes in Drosophila.

Measuring the immune system: a comprehensive approach for the analysis of immune functions in humans.

PubMed

Claus, Maren; Dychus, Nicole; Ebel, Melanie; Damaschke, Jürgen; Maydych, Viktoriya; Wolf, Oliver T; Kleinsorge, Thomas; Watzl, Carsten

2016-10-01

The immune system is essential to provide protection from infections and cancer. Disturbances in immune function can therefore directly affect the health of the affected individual. Many extrinsic and intrinsic factors such as exposure to chemicals, stress, nutrition and age have been reported to influence the immune system. These influences can affect various components of the immune system, and we are just beginning to understand the causalities of these changes. To investigate such disturbances, it is therefore essential to analyze the different components of the immune system in a comprehensive fashion. Here, we demonstrate such an approach which provides information about total number of leukocytes, detailed quantitative and qualitative changes in the composition of lymphocyte subsets, cytokine levels in serum and functional properties of T cells, NK cells and monocytes. Using samples from a cohort of 24 healthy volunteers, we demonstrate the feasibility of our approach to detect changes in immune functions.

Diagnosis and management of maxillary incisors affected by incisal wear: an interdisciplinary case report.

PubMed

Bernardo, Jussara Karina; Maia, Elaine A Vilela; Cardoso, Antônio Carlos; de Araújo Júnior, Edson Medeiros; Monteiro Júnior, Sylvio

2002-01-01

In the attempt to restore anterior teeth affected by erosion and bruxism, many clinicians have been frustrated with the constant restorative failures. Frequently, these failures are attributed to the restorative materials employed, especially in cases in which composite resins are used. However, some flaws of the restorations are related to the oversight of occlusal principles. The purpose of this article is to discuss the etiology, signs, and symptoms of incisal wear, with special attention to that caused by bruxism and chemical erosion. Relatively simple management techniques (e.g., occlusal adjustment, adhesive restorations) are proposed, and the diagnosis and management of a representative clinical case is presented. In some cases of bruxism and/or dental erosion, it is possible to acquire space to recuperate the esthetics and function of maxillary incisors affected by incisal wear through a conservative treatment associated with the control of the etiologic factors.

Forecasting of municipal solid waste quantity in a developing country using multivariate grey models.

PubMed

Intharathirat, Rotchana; Abdul Salam, P; Kumar, S; Untong, Akarapong

2015-05-01

In order to plan, manage and use municipal solid waste (MSW) in a sustainable way, accurate forecasting of MSW generation and composition plays a key role. It is difficult to carry out the reliable estimates using the existing models due to the limited data available in the developing countries. This study aims to forecast MSW collected in Thailand with prediction interval in long term period by using the optimized multivariate grey model which is the mathematical approach. For multivariate models, the representative factors of residential and commercial sectors affecting waste collected are identified, classified and quantified based on statistics and mathematics of grey system theory. Results show that GMC (1, 5), the grey model with convolution integral, is the most accurate with the least error of 1.16% MAPE. MSW collected would increase 1.40% per year from 43,435-44,994 tonnes per day in 2013 to 55,177-56,735 tonnes per day in 2030. This model also illustrates that population density is the most important factor affecting MSW collected, followed by urbanization, proportion employment and household size, respectively. These mean that the representative factors of commercial sector may affect more MSW collected than that of residential sector. Results can help decision makers to develop the measures and policies of waste management in long term period. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stimulation of soil nitrification and denitrification by grazing in grasslands: do changes in plant species composition matter?

PubMed

Le Roux, X; Bardy, M; Loiseau, P; Louault, F

2003-11-01

Stimulation of nitrification and denitrification by long term (from years to decades) grazing has commonly been reported in different grassland ecosystems. However, grazing generally induces important changes in plant species composition, and whether changes in nitrification and denitrification are primarily due to changes in vegetation composition has never been tested. We compared soil nitrification- and denitrification-enzyme activities (NEA and DEA, respectively) between semi-natural grassland sites experiencing intensive (IG) and light (LG) grazing/mowing regimes for 13 years. Mean NEA and DEA (i.e. observed from random soil sampling) were higher in IG than LG sites. The NEA/DEA ratio was higher in IG than LG sites, indicating a higher stimulation of nitrification. Marked changes in plant species composition were observed in response to the grazing/mowing regime. In particular, the specific phytomass volume of Elymus repens was lower in IG than LG sites, whereas the specific volume of Lolium perenne was higher in IG than LG sites. In contrast, the specific volume of Holcus lanatus, Poa trivialis and Arrhenatherum elatius were not significantly different between treatments. Soils sampled beneath grass tussocks of the last three species exhibited higher DEA, NEA and NEA/DEA ratio in IG than LG sites. For a given grazing regime, plant species did not affect significantly soil DEA, NEA and NEA/DEA ratio. The modification of plant species composition is thus not the primary factor driving changes in nitrification and denitrification in semi-natural grassland ecosystems experiencing long term intensive grazing. Factors such as trampling, N returned in animal excreta, and/or modification of N uptake and C exudation by frequently defoliated plants could be responsible for the enhanced microbial activities.

Maternal fat free mass during pregnancy is associated with birth weight.

PubMed

Wang, Yanxia; Mao, Jie; Wang, Wenling; Qiou, Jie; Yang, Lan; Chen, Simin

2017-03-28

The relationship between maternal body compositions and birth weight was not definite. Fat Mass (FM) and Fat Free Mass (FFM) can accurately reflect the maternal body fat compositions and have been considered as better predictors of birth weight. Despite its potential role, no studies have been described the maternal compositions during pregnancy in East Asian women previously. We investigated the correlation between birth weight and Maternal body composition including fat mass (FM) and fat free mass (FFM). To determine whether birth weight is associated with maternal body fat FM and FFM during pregnancy and, if so, which trimester and parameter is more critical in determining birth weight. A longitudinal prospective observational study performed, 348, 481 and 321 non-diabetics Han Chinese women with a singleton live birth attending a routine visit in their first, second and third trimesters were recruited. Maternal body composition was measured using segmental multi-frequency bioelectrical impedance analysis. Data of the pre-pregnancy body mass index (BMI), maternal BMI, the gestational weight gain (GWG), and placental and birth weight were collected. A significant correlation exists between maternal FFM in the process of pregnancy, placental weight, GWG at delivery, and birth weight (P < 0.05). On stepwise multiple linear regression analysis, material's FFM was the most important factor associated with the birth weight. After adjustment, there was significantly associated with 2.47-fold increase in risk for birth weight more than 4 kg when FFM ≥ 40.76 kg (Upper quartile of participants). The increased maternal age became a protective factor (OR = 0.69) while the increased pre-pregnancy BMI (OR = 1.50) remained predictors to birth weight more than 4 kg. The change of maternal FFM during pregnancy is independently affected the birth weight.

Effect of acid and laser etching on shear bond strength of conventional and resin-modified glass-ionomer cements to composite resin.

PubMed

Navimipour, Elmira Jafari; Oskoee, Siavash Savadi; Oskoee, Parnian Alizadeh; Bahari, Mahmoud; Rikhtegaran, Sahand; Ghojazadeh, Morteza

2012-03-01

Success in sandwich technique procedures can be achieved through an acceptable bond between the materials. The aim of this study was to compare the effect of 35% phosphoric acid and Er,Cr:YSGG laser on shear bond strength of conventional glass-ionomer cement (GIC) and resin-modified glass-ionomer cement (RMGIC) to composite resin in sandwich technique. Sixty-six specimens were prepared from each type of glass-ionomer cements and divided into three treatment groups as follows: without pretreatment, acid etching by 35% phosphoric acid for 15 s, and 1-W Er,Cr:YSGG laser treatment for 15 s with a 600-μm-diameter tip aligned perpendicular to the target area at a distance of 1 mm from the surface. Energy density of laser irradiation was 17.7 J/cm(2). Two specimens in each group were prepared for evaluation under a scanning electron microscope (SEM) after surface treatment and the remainder underwent bonding procedure with a bonding agent and composite resin. Then the shear bond strength was measured at a crosshead speed of 0.5 mm/min. Two-factor analysis of variance and post-hoc Tukey test showed that the cement type, surface treatment method, and the interaction of these two factors significantly affect the shear bond strength between glass-ionomer cements and composite resin (p < 0.05). Surface treatment with phosphoric acid or Er,Cr:YSGG laser increased the shear bond strength of GIC to composite resin; however, in RMGIC only laser etching resulted in significantly higher bond strength. These findings were supported by SEM results. The fracture mode was evaluated under a stereomicroscope at ×20.

Mixing of water masses caused by a drifting iceberg affects bacterial activity, community composition and substrate utilization capability in the Southern Ocean.

PubMed

Dinasquet, Julie; Richert, Inga; Logares, Ramiro; Yager, Patricia; Bertilsson, Stefan; Riemann, Lasse

2017-06-01

The number of icebergs produced from ice-shelf disintegration has increased over the past decade in Antarctica. These drifting icebergs mix the water column, influence stratification and nutrient condition, and can affect local productivity and food web composition. Data on whether icebergs affect bacterioplankton function and composition are scarce, however. We assessed the influence of iceberg drift on bacterial community composition and on their ability to exploit carbon substrates during summer in the coastal Southern Ocean. An elevated bacterial production and a different community composition were observed in iceberg-influenced waters relative to the undisturbed water column nearby. These major differences were confirmed in short-term incubations with bromodeoxyuridine followed by CARD-FISH. Furthermore, one-week bottle incubations amended with inorganic nutrients and carbon substrates (a mix of substrates, glutamine, N-acetylglucosamine, or pyruvate) revealed contrasting capacity of bacterioplankton to utilize specific carbon substrates in the iceberg-influenced waters compared with the undisturbed site. Our study demonstrates that the hydrographical perturbations introduced by a drifting iceberg can affect activity, composition, and substrate utilization capability of marine bacterioplankton. Consequently, in a context of global warming, increased frequency of drifting icebergs in polar regions holds the potential to affect carbon and nutrient biogeochemistry at local and possibly regional scales. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Source/process apportionment of major and trace elements in sinking particles in the Sargasso sea

NASA Astrophysics Data System (ADS)

Huang, S.; Conte, M. H.

2009-01-01

Elemental composition of the particle flux at the Oceanic Flux Program (OFP) time-series site off Bermuda was measured from January 2002 to March 2005. Eighteen elements (Mg, Al, Si, P, Ca, Sc, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Sr, Cd, Ba and Pb) in sediment trap material from 500, 1500 and 3200 m depths were quantified using fusion-HR-ICPMS. Positive Matrix Factorization (PMF) was used to elucidate sources, elemental associations and processes that affect geochemical behavior in the water column. Results provide evidence for intense elemental cycling between the sinking flux material and the dissolved and suspended pools within mesopelagic and bathypelagic waters. Biological processing and remineralization rapidly deplete the sinking flux material in organic matter and associated elements (N, P, Cd, Zn) between 500 and 1500 m depth. Suspended particle aggregation, authigenic mineral precipitation, and chemical scavenging enriches the flux material in lithogenic minerals, barite and redox sensitive elements (Mn, Co, V, Fe). A large increase in the flux of lithogenic elements is observed with depth and confirms that the northeast Sargasso is a significant sink for advected continental materials, likely supplied via Gulf Stream circulation. PMF resolved major sources that contribute to sinking flux at all depths (carbonate, high-Mg carbonate, opal, organic matter, lithogenic material, and barite) as well as additional depth-specific elemental associations that contribute about half of the compositional variability in the flux. PMF solutions indicate close geochemical associations of barite-opal, Cd-P, Zn-Co, Zn-Pb and redox sensitive elements in the sinking flux material at 500 m depth. Major reorganizations of element associations occur as labile carrier phases break down and elements redistribute among new carrier phases deeper in the water column. Factor scores show strong covariation and similar temporal phasing among the three trap depths and indicate a tight coupling in particle flux compositional variability throughout the water column. Seasonality in flux composition is primarily driven by dilution of the lithogenic component with freshly-produced biogenic material during the late winter primary production maximum. Temporal trends in scores reveal subtle non-seasonal changes in flux composition occurring on month long timescales. This non-seasonal variability may be driven by changes in the biogeochemical properties of intermediate water masses that pass through the region and which affect rates of chemical scavenging and/or aggregation within the water column.

Rhizosphere Competence and Biocontrol Effect of Pseudomonas sp. RU47 Independent from Plant Species and Soil Type at the Field Scale.

PubMed

Schreiter, Susanne; Babin, Doreen; Smalla, Kornelia; Grosch, Rita

2018-01-01

Biocontrol inoculants often show inconsistency in their efficacy at field scale and the reason for this remains often unclear. A high rhizosphere competence of inoculant strains is assumed to be a key factor for successful biocontrol effects as the biocontrol strain has to compete with the indigenous microbial community in the rhizosphere. It is known that many factors, among them plant species and soil type shape the rhizosphere microbial community composition. However, microbial community composition in the rhizosphere can also be influenced by the presence of a pathogen. We hypothesized that plant species, soil type, and a pathogen affect the rhizosphere competence of a biocontrol strain and its biocontrol effect against a soil-borne pathogen. To test the hypothesis, we used an experimental plot system with three soil types (diluvial sand, alluvial loam, loess loam) kept under similar agricultural management at the same field site for 12 years. We investigate the rhizosphere competence of Pseudomonas sp. RU47 in two plant species (potato and lettuce) and its biocontrol effect against Rhizoctonia diseases. The colonization density of a rifampicin resistant mutant of RU47 in the rhizosphere of both crops was evaluated by plate counts. Bacterial community compositions were analyzed by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments amplified from total community DNA. The inoculant RU47 was able to colonize the rhizosphere of both model crops in a sufficient density and to reduce disease severity of black scurf on potato and bottom rot on lettuce in all three soils. DGGE indicated that RU47 affected the bacterial community composition stronger in the rhizosphere of lettuce than in the potato rhizosphere. In contrast, the effect of the pathogen Rhizoctonia solani on the bacterial community was much stronger in the rhizosphere of potato than in the lettuce rhizosphere. A significant effect of RU47 on the Pseudomonas -specific gacA fingerprints of the rhizosphere was only observed in lettuce in alluvial soil. The soil type and plant species independent biocontrol effects of RU47 and its minor influence on the indigenous bacterial community composition might be important criteria for the registration and use of RU47 as biocontrol strain.

Rhizosphere Competence and Biocontrol Effect of Pseudomonas sp. RU47 Independent from Plant Species and Soil Type at the Field Scale

PubMed Central

Schreiter, Susanne; Babin, Doreen; Smalla, Kornelia; Grosch, Rita

2018-01-01

Biocontrol inoculants often show inconsistency in their efficacy at field scale and the reason for this remains often unclear. A high rhizosphere competence of inoculant strains is assumed to be a key factor for successful biocontrol effects as the biocontrol strain has to compete with the indigenous microbial community in the rhizosphere. It is known that many factors, among them plant species and soil type shape the rhizosphere microbial community composition. However, microbial community composition in the rhizosphere can also be influenced by the presence of a pathogen. We hypothesized that plant species, soil type, and a pathogen affect the rhizosphere competence of a biocontrol strain and its biocontrol effect against a soil-borne pathogen. To test the hypothesis, we used an experimental plot system with three soil types (diluvial sand, alluvial loam, loess loam) kept under similar agricultural management at the same field site for 12 years. We investigate the rhizosphere competence of Pseudomonas sp. RU47 in two plant species (potato and lettuce) and its biocontrol effect against Rhizoctonia diseases. The colonization density of a rifampicin resistant mutant of RU47 in the rhizosphere of both crops was evaluated by plate counts. Bacterial community compositions were analyzed by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments amplified from total community DNA. The inoculant RU47 was able to colonize the rhizosphere of both model crops in a sufficient density and to reduce disease severity of black scurf on potato and bottom rot on lettuce in all three soils. DGGE indicated that RU47 affected the bacterial community composition stronger in the rhizosphere of lettuce than in the potato rhizosphere. In contrast, the effect of the pathogen Rhizoctonia solani on the bacterial community was much stronger in the rhizosphere of potato than in the lettuce rhizosphere. A significant effect of RU47 on the Pseudomonas-specific gacA fingerprints of the rhizosphere was only observed in lettuce in alluvial soil. The soil type and plant species independent biocontrol effects of RU47 and its minor influence on the indigenous bacterial community composition might be important criteria for the registration and use of RU47 as biocontrol strain. PMID:29449832

Analysis of factors affecting the accuracy, reproducibility, and interpretation of microbial community carbon source utilization patterns

USGS Publications Warehouse

Haack, S.K.; Garchow, H.; Klug, M.J.; Forney, L.J.

1995-01-01

We determined factors that affect responses of bacterial isolates and model bacterial communities to the 95 carbon substrates in Biolog microliter plates. For isolates and communities of three to six bacterial strains, substrate oxidation rates were typically nonlinear and were delayed by dilution of the inoculum. When inoculum density was controlled, patterns of positive and negative responses exhibited by microbial communities to each of the carbon sources were reproducible. Rates and extents of substrate oxidation by the communities were also reproducible but were not simply the sum of those exhibited by community members when tested separately. Replicates of the same model community clustered when analyzed by principal- components analysis (PCA), and model communities with different compositions were clearly separated un the first PCA axis, which accounted for >60% of the dataset variation. PCA discrimination among different model communities depended on the extent to which specific substrates were oxidized. However, the substrates interpreted by PCA to be most significant in distinguishing the communities changed with reading time, reflecting the nonlinearity of substrate oxidation rates. Although whole-community substrate utilization profiles were reproducible signatures for a given community, the extent of oxidation of specific substrates and the numbers or activities of microorganisms using those substrates in a given community were not correlated. Replicate soil samples varied significantly in the rate and extent of oxidation of seven tested substrates, suggesting microscale heterogeneity in composition of the soil microbial community.

Factors influencing the grass carp gut microbiome and its effect on metabolism.

PubMed

Ni, Jiajia; Yan, Qingyun; Yu, Yuhe; Zhang, Tanglin

2014-03-01

Gut microbiota have attracted extensive attention recently because of their important role in host metabolism, immunity and health maintenance. The present study focused on factors affecting the gut microbiome of grass carp (Ctenopharyngodon idella) and further explored the potential effect of the gut microbiome on metabolism. Totally, 43.39 Gb of screened metagenomic sequences obtained from 24 gut samples were fully analysed. We detected 1228 phylotypes (116 Archaea and 1112 Bacteria), most of which belonged to the phyla Firmicutes, Proteobacteria and Fusobacteria. Totally, 41335 of the detected open reading frames (ORFs) were matched to Kyoto Encyclopedia of Genes and Genomes pathways, and carbohydrate and amino acid metabolism was the main matched pathway deduced from the annotated ORFs. Redundancy analysis based on the phylogenetic composition and gene composition of the gut microbiome indicated that gut fullness and feeding (i.e. ryegrass vs. commercial feed, and pond-cultured vs. wild) were significantly related to the gut microbiome. Moreover, many biosynthesis and metabolism pathways of carbohydrates, amino acids and lipids were significantly enhanced by the gut microbiome in ryegrass-fed grass carp. These findings suggest that the metabolic role played by the gut microbiome in grass carp can be affected by feeding. These findings contribute to the field of fish gut microbial ecology and also provide a basis for follow-up functional studies. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Proximate composition, antihypertensive and antioxidative properties of the semimembranosus muscle from pork and beef after cooking and in vitro digestion.

PubMed

Jensen, Ida-Johanne; Dort, Junio; Eilertsen, Karl-Erik

2014-02-01

The aims of this study were to evaluate and compare proximate composition, antihypertensive activity and antioxidative capacity of the semimembranosus muscle from pork and beef and to study how these characteristics were affected by household preparation and subsequent digestion. The proximate composition was similar between pork and beef. Both pork and beef contained protein with the essential amino acids. Cooking in a heated pan did not affect the retention of lipid or sum of amino acids, but reduced the amount of the free amino acid taurine. The antihypertensive effect did not differ significantly between pork and beef, whereas the antioxidative capacity did. Cooking affected the antioxidative capacity negatively. The results from this study show that pork and beef are equally good sources of protein and bioactive properties, and whereas the nutritional composition is not affected, bioactive properties may be reduced after household preparations. © 2013.

Biological soil crusts: An organizing principle in dryland ecosystems (aka: the role of biocrusts in arid land hydrology)

USGS Publications Warehouse

Chamizo, Sonia; Belnap, Jayne; Elridge, David J; Issa, Oumarou M

2016-01-01

Biocrusts exert a strong influence on hydrological processes in drylands by modifying numerous soil properties that affect water retention and movement in soils. Yet, their role in these processes is not clearly understood due to the large number of factors that act simultaneously and can mask the biocrust effect. The influence of biocrusts on soil hydrology depends on biocrust intrinsic characteristics such as cover, composition, and external morphology, which differ greatly among climate regimes, but also on external factors as soil type, topography and vegetation distribution patterns, as well as interactions among these factors. This chapter reviews the most recent literature published on the role of biocrusts in infiltration and runoff, soil moisture, evaporation and non-rainfall water inputs (fog, dew, water absorption), in an attempt to elucidate the key factors that explain how biocrusts affect land hydrology. In addition to the crust type and site characteristics, recent studies point to the crucial importance of the type of rainfall and the spatial scale at which biocrust effects are analyzed to understand their role in hydrological processes. Future studies need to consider the temporal and spatial scale investigated to obtain more accurate generalizations on the role of biocrusts in land hydrology.

Turbidity in oil-in-water-emulsions - Key factors and visual perception.

PubMed

Linke, C; Drusch, S

2016-11-01

The aim of the present study is to systematically describe the factors affecting turbidity in beverage emulsions and to get a better understanding of visual perception of turbidity. The sensory evaluation of the human visual perception of turbidity showed that humans are most sensitive to turbidity differences between two samples in the range between 1000 and 1500 NTU (ratio) (nephelometric turbidity units). At very high turbidity values >2000 TU in NTU (ratio) were needed to distinguish between samples that they were perceived significantly different. Particle size was the most important factor affecting turbidity. It was shown that a maximum turbidity occurs at a mean volume - surface diameter of 0.2μm for the oil droplet size. Additional parameters were the refractive index, the composition of the aqueous phase and the presence of excess emulsifier. In a concentration typical for a beverage emulsion a change in the refractive index of the oil phase may allow the alteration of turbidity by up to 30%. With the knowledge on visual perception of turbidity and the determining factors, turbidity can be tailored in product development according to the customer requirements and in quality control to define acceptable variations in optical appearance. Copyright © 2016. Published by Elsevier Ltd.

A guide to structural factors for advanced composites used on spacecraft

NASA Technical Reports Server (NTRS)

Vanwagenen, Robert

1989-01-01

The use of composite materials in spacecraft systems is constantly increasing. Although the areas of composite design and fabrication are maturing, they remain distinct from the same activities performed using conventional materials and processes. This has led to some confusion regarding the precise meaning of the term 'factor of safety' as it applies to these structures. In addition, composite engineering introduces terms such as 'knock-down factors' to further modify material properties for design purposes. This guide is intended to clarify these terms as well as their use in the design of composite structures for spacecraft. It is particularly intended to be used by the engineering community not involved in the day-to-day composites design process. An attempt is also made to explain the wide range of factors of safety encountered in composite designs as well as their relationship to the 1.4 factor of safety conventionally applied to metallic structures.

Effects of Flavor and Texture on the Sensory Perception of Gouda-Type Cheese Varieties during Ripening Using Multivariate Analysis.

PubMed

Shiota, Makoto; Iwasawa, Ai; Suzuki-Iwashima, Ai; Iida, Fumiko

2015-12-01

The impact of flavor composition, texture, and other factors on desirability of different commercial sources of Gouda-type cheese using multivariate analyses on the basis of sensory and instrumental analyses were investigated. Volatile aroma compounds were measured using headspace solid-phase microextraction gas chromatography/mass spectrometry (GC/MS) and steam distillation extraction (SDE)-GC/MS, and fatty acid composition, low-molecular-weight compounds, including amino acids, and organic acids, as well pH, texture, and color were measured to determine their relationship with sensory perception. Orthogonal partial least squares-discriminant analysis (OPLS-DA) was performed to discriminate between 2 different ripening periods in 7 sample sets, revealing that ethanol, ethyl acetate, hexanoic acid, and octanoic acid increased with increasing sensory attribute scores for sweetness, fruity, and sulfurous. A partial least squares (PLS) regression model was constructed to predict the desirability of cheese using these parameters. We showed that texture and buttery flavors are important factors affecting the desirability of Gouda-type cheeses for Japanese consumers using these multivariate analyses. © 2015 Institute of Food Technologists®

The Relationship between the Second-to-Fourth Digit Ratio and Behavioral Sexual Dimorphism in School-Aged Children.

PubMed

Mitsui, Takahiko; Araki, Atsuko; Miyashita, Chihiro; Ito, Sachiko; Ikeno, Tamiko; Sasaki, Seiko; Kitta, Takeya; Moriya, Kimihiko; Cho, Kazutoshi; Morioka, Keita; Kishi, Reiko; Shinohara, Nobuo; Takeda, Masayuki; Nonomura, Katsuya

2016-01-01

Sexually dimorphic brain development and behavior are known to be influenced by sex hormones exposure in prenatal periods. On the other hand, second-to forth digit ratio (2D/4D) has been used as an indirect method to investigate the putative effects of prenatal exposure to androgen. In the present study, we herein investigated the relationship between gender-role play behavior and the second-to-fourth digit ratio (2D/4D), which has been used as an indirect method to investigate the putative effects of prenatal exposure to androgens, in school-aged children. Among 4981 children who became 8 years old by November 2014 and were contactable for this survey by The Hokkaido Study of Environment and Children's Health, 1631 (32.7%), who had data for 2D/4D and Pre-school Activities Inventory (PSAI) as well as data for the survey at baseline, were available for analysis. Parents sent reports of PSAI on the sex-typical characteristics, preferred toys, and play activities of children, and black and white photocopies of the left and right hand palms via mail. PSAI consisted of 12 masculine items and 12 feminine items, and a composite score was created by subtracting the feminine score from the masculine score, with higher scores representing masculine-typical behavior. While composite scores in PSAI were significantly higher in boys than in girls, 2D/4D was significantly lower in boys than in girls. Although the presence or absence of brothers or sisters affected the composite, masculine, and feminine scored of PSAI, a multivariate regression model revealed that 2D/4D negatively correlated with the composite scores of PSAI in boys, whereas no correlation was found in girls. Although 2D/4D negatively correlated with the masculine score in boys and girls, no correlation was observed between 2D/4D and the feminine score. In conclusion, although social factors, such as the existence of brother or sisters, affect dimorphic brain development and behavior in childhood, the present study revealed that the prenatal hormonal environment was an important factor influencing masculine-typical dimorphic brain development and behavior in school-aged children.

Are unilateral and bilateral patellar tendinopathy distinguished by differences in anthropometry, body composition, or muscle strength in elite female basketball players?

PubMed Central

Gaida, J; Cook, J; Bass, S; Austen, S; Kiss, Z

2004-01-01

Background: Overuse injury to the patellar tendon (patellar tendinopathy) is a major reason for interrupted training and competition for elite athletes. In both sexes, the prevalence of unilateral and bilateral tendinopathy has been shown to differ. It has been proposed that bilateral pathology may have a different aetiology from unilateral pathology. Investigation of risk factors that may be unique to unilateral and bilateral patellar tendinopathy in female athletes may reveal insights into the aetiology of this condition. Objectives: To examine whether anthropometry, body composition, or muscle strength distinguished elite female basketball players with unilateral or bilateral patellar tendinopathy. Methods: Body composition, anthropometry, and muscle strength were compared in elite female basketball players with unilateral (n = 8), bilateral (n = 7), or no (n = 24) patellar tendinopathy. Body composition was analysed using a dual energy x ray absorptiometer. Anthropometric measures were assessed using standard techniques. Knee extensor strength was measured at 180°/s using an isokinetic dynamometer. z scores were calculated for the unilateral and bilateral groups (using the no tendinopathy group as controls). z scores were tested against zero. Results: The tibia length to stature ratio was approximately 1.3 (1.3) SDs above zero in both the affected and non-affected legs in the unilateral group (p<0.05). The waist to hip ratio was 0.66 (0.78) SD above zero in the unilateral group (p<0.05). In the unilateral group, leg lean to total lean ratio was 0.42 (0.55) SD above zero (p<0.07), the trunk lean to total lean ratio was 0.63 (0.68) SD below zero (p<0.05), and leg fat relative to total fat was 0.47 (0.65) SD below zero (p<0.09). In the unilateral group, the leg with pathology was 0.78 (1.03) SD weaker during eccentric contractions (p<0.07). Conclusions: Unilateral patellar tendinopathy has identifiable risk factors whereas bilateral patellar tendinopathy may not. This suggests that the aetiology of these conditions may be different. However, interpretation must respect the limitation of small subject numbers. PMID:15388543

The ecological relationship between deprivation, social isolation and rates of hospital admission for acute psychiatric care: a comparison of London and New York City.

PubMed

Curtis, Sarah; Copeland, Alison; Fagg, James; Congdon, Peter; Almog, Michael; Fitzpatrick, Justine

2006-03-01

We report on comparative analyses of small area variation in rates of acute hospital admissions for psychiatric conditions in Greater London around the year 1998 and in New York City (NYC) in 2000. Based on a theoretical model of the factors likely to influence psychiatric admission rates, and using data from the most recent population censuses and other sources, we examine the association with area indicators designed to measure access to hospital beds, socio-economic deprivation, social fragmentation and ethnic/racial composition. We report results on admissions for men and women aged 15-64 for all psychiatric conditions (excluding self-harm), drug-related substance abuse/addiction, schizophrenia and affective disorders. The units of analysis in NYC were 165 five-digit Zip Code Areas and, in London, 760 electoral wards as defined in 1998. The analysis controls for age and sex composition and, as a proxy for access to care, spatial proximity to hospitals with psychiatric beds. Poisson regression modeling incorporating random effects was used to control for both overdispersion in the counts of admissions and for the effects of spatial autocorrelation. The results for NYC and London showed that local admission rates for all types of condition were positively and significantly associated with deprivation and the association is independent of demographic composition or 'access' to beds. In NYC, social fragmentation showed a significant association with admissions due to affective disorders and schizophrenia, and for drug dependency among females. Racial minority concentration was significantly and positively associated with admissions for schizophrenia. In London, social fragmentation was associated positively with admissions for men and women due to schizophrenia and affective disorders. The variable measuring racial/ethnic minority concentration for London wards showed a negative association with admission rates for drug dependency and for affective disorders. We discuss the interpretation of these results and the issues they raise in terms of the potential and limitations of international comparison.

Fish diversity in the Río de la Plata and adjacent waters: an overview of environmental influences on its spatial and temporal structure.

PubMed

Jaureguizar, A J; Solari, A; Cortés, F; Milessi, A C; Militelli, M I; Camiolo, M D; Luz Clara, M; García, M

2016-07-01

The fish diversity and the main environmental factors affecting the spatial distribution of species, life history stages and community structure in the Río de la Plata (RdP) and adjacent waters are reviewed and analysed, with emphasis on the functional guild classification. The functional guild classification indicated that most species in the RdP were marine stragglers, zoobenthivores and oviparous species, although the biomass was dominated by estuarine species. Salinity had a stronger influence than temperature on the spatial pattern for all life stages, shallower and fresher waters are the preferred habitats of neonates and juveniles. During the breeding season (spring-summer), adults showed an intrusion into the inner part of RdP or to its adjacent nearshore waters from the offshore waters for spawning or mating, respectively. Variations in river discharge and wind patterns greatly affected the spatial extent of estuarine water, which ultimately influenced the domain of the main life-history stages (juveniles or adults) for both marine and estuarine fishes, as well as species and fish assemblage composition. The strong environmental gradient restricts some species and life-history stages to a particular section and defines three main fish assemblage areas. The composition of the fish assemblage is indicative of the recruitment of freshwater and marine species to the estuary in opposite ways, determined by the vertical stratification. Seasonal changes in the species composition were related to migration as a result of salinity and temperature variations and reproductive migrations to spawning and mating areas. This overview reveals that the RdP is under environmental variations that are likely to produce modifications to fish distribution and abundance that affect its fisheries. This context plus fish stock declines and changes in exploitation patterns could amplify the magnitude of the variations in the fisheries resources availability and affect the sustainability of fishing communities. © 2016 The Fisheries Society of the British Isles.

Food restriction followed by refeeding with a casein- or whey-based diet differentially affects the gut microbiota of pre-pubertal male rats.

PubMed

Masarwi, Majdi; Solnik, Hadas Isaac; Phillip, Moshe; Yaron, Sima; Shamir, Raanan; Pasmanic-Chor, Metsada; Gat-Yablonski, Galia

2018-01-01

Researchers are gaining an increasing understanding of host-gut microbiota interactions, but studies of the role of gut microbiota in linear growth are scarce. The aim of this study was to investigate the effect of food restriction and refeeding with different diets on gut microbiota composition in fast-growing rats. Young male Sprague-Dawley rats were fed regular rat chow ad libitum (control group) or subjected to 40% food restriction for 36 days followed by continued restriction or ad libitum refeeding for 24 days. Three different diets were used for refeeding: regular vegetarian protein chow or chow in which the sole source of protein was casein or whey. In the control group, the composition of the microbiota remained stable. Food restriction for 60 days led to a significant change in the gut microbiota at the phylum level, with a reduction in the abundance of Firmicutes and an increase in Bacteroidetes and Proteobacteria. Rats refed with the vegetarian protein diet had a different microbiota composition than rats refed the casein- or whey-based diet. Similarities in the bacterial population were found between rats refed vegetarian protein or a whey-based diet and control rats, and between rats refed a casein-based diet and rats on continued restriction. There was a significant strong correlation between the gut microbiota and growth parameters: humerus length, epiphyseal growth plate height, and levels of insulin-like growth factor 1 and leptin. In conclusion, the type of protein in the diet significantly affects the gut microbiota and, thereby, may affect animal's health. Copyright © 2017 Elsevier Inc. All rights reserved.

Exercise program affects body composition but not weight in postmenopausal women.

PubMed

Velthuis, Miranda J; Schuit, Albertine J; Peeters, Petra H M; Monninkhof, Evelyn M

2009-01-01

The aim of this study was to investigate the effect of a 12-month moderate-to-vigorous exercise program combining aerobic and muscle strength training on body composition among sedentary, postmenopausal women. A randomized controlled trial was conducted. A total of 189 sedentary postmenopausal women (age 50-69 y, body mass index 22-40 kg/m2) were randomly assigned to an exercise (n = 96) or a control group (n = 93). Study parameters measured at baseline, 4 months, and 12 months were as follows: body weight and body height (body mass index), waist and hip circumference (body fat distribution), and dual-energy x-ray absorptiometry (total body fat and lean mass). Differences in changes in study parameters between exercise and control group were examined with generalized estimating equations analysis. The exercise program did not result in significant effects on weight, body mass index, and hip circumference. The exercise group experienced a statistically significant greater loss in total body fat, both absolute (-0.33 kg) (borderline) as in a percentage (-0.43%) compared with the control group. In addition, lean mass increased significantly (+0.31 kg), whereas waist circumference (-0.57 cm) decreased significantly compared with the control group. We conclude that a 12-month exercise program combining aerobic and muscle strength training did not affect weight but positively influenced body composition of postmenopausal women. Affecting body fat distribution and waist circumference may have important health implications because it is an independent risk factor in obese but also in nonobese people. Therefore, this study gives further credence to efforts of public health and general practitioners aiming to increase physical activity levels of postmenopausal women.

Effect of somatic cell count and mastitis pathogens on milk composition in Gyr cows

PubMed Central

2013-01-01

Background Gyr cows are well adapted to tropical conditions, resistant to some tropical diseases and have satisfactory milk production. However, Gyr dairy herds have a high prevalence of subclinical mastitis, which negatively affects their milk yield and composition. The objectives of this study were (i) to evaluate the effects of seasonality, mammary quarter location (rear x front), mastitis-causing pathogen species, and somatic cell count (SCC) on milk composition in Gyr cows with mammary quarters as the experimental units and (ii) to evaluate the effects of seasonality and somatic cell count (SCC) on milk composition in Gyr cows with cows as the experimental units. A total of 221 lactating Gyr cows from three commercial dairy farms were selected for this study. Individual foremilk quarter samples and composite milk samples were collected once a month over one year from all lactating cows for analysis of SCC, milk composition, and bacteriological culture. Results Subclinical mastitis reduced lactose, nonfat solids and total solids content, but no difference was found in the protein and fat content between infected and uninfected quarters. Seasonality influenced milk composition both in mammary quarters and composite milk samples. Nevertheless, there was no effect of mammary quarter position on milk composition. Mastitis-causing pathogens affected protein, lactose, nonfat solids, and total solids content, but not milk fat content. Somatic cell count levels affected milk composition in both mammary quarters and composite samples of milk. Conclusions Intramammary infections in Gyr cows alter milk composition; however, the degree of change depends on the mastitis-causing pathogen. Somatic cell count is negatively associated with reduced lactose and nonfat solids content in milk. Seasonality significantly affects milk composition, in which the concentration of lactose, fat, protein, nonfat solids and total solids differs between dry and wet seasons in Gyr cows. PMID:23566405

Effects of fertilization, crop year, variety, and provenance factors on mineral concentrations in onions.

PubMed

Ariyama, Kaoru; Nishida, Tadashi; Noda, Tomoaki; Kadokura, Masashi; Yasui, Akemi

2006-05-03

Mineral concentrations of onions (Allium cepa L.) grown under various conditions, including factors (fertilization, crop year, variety, and provenance), were investigated to clarify how much each factor contributes to the variation of their concentrations. This was because the mineral concentrations might be affected by various factors. The ultimate goal of this study was to develop a technique to determine the geographic origins of onions by mineral composition. Samples were onions grown under various conditions at 52 fields in 18 farms in Hokkaido, Japan. Twenty-six elements (Li, Na, Mg, Al, P, K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Mo, Cd, Cs, Ba, La, Ce, Nd, Gd, W, and Tl) in these samples were determined by inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry. Fertilization conditions and crop years of onions caused variations of P, Ni, Cu, Rb, Sr, Mo, Cs, and Tl concentrations in onions; different onion varieties also showed variations in numerous element concentrations. However, the variations of mineral compositions of onions by these factors were smaller than the differences between production places with a few exceptions. Furthermore, Na, Rb, and Cs in group IA of the periodic table, Ca, Sr, and Ba in group IIA, and Zn and Cd in group IIB showed similar concentration patterns by group; this result demonstrated that elements in the same periodic groups behaved similarly in terms of their absorption in onions.

Gasoline Composition Regulations Affecting LUST Sites

EPA Science Inventory

Passage of the Clean Air Act Amendments in 1990 imposed requirements on gasoline composition in the United States. Impacts to ground water are affected by the provisions that required oxygenated additives and limited benzene concentration. Reformulated and oxygenated gasoline w...

TiO2/bone composite materials for the separation of heavy metal impurities from waste water solutions

NASA Astrophysics Data System (ADS)

Dakroury, G.; Labib, Sh.; Abou El-Nour, F. H.

2012-09-01

Pure bone material obtained from cow meat, as apatite-rich material, and TiO2-bone composite materials are prepared and studied to be used for heavy metal ions separation from waste water solutions. Meat wastes are chemically and thermally treated to control their microstructure in order to prepare the composite materials that fulfill all the requirements to be used as selective membranes with high performance, stability and mechanical strength. The prepared materials are analyzed using Hg-porosimetry for surface characterization, energy dispersive X-ray spectroscopy (EDAX) for elemental analysis and Fourier transform infrared spectroscopy (FTIR) for chemical composition investigation. Structural studies are performed using X-ray diffraction (XRD). Microstructural properties are studied using scanning electron microscopy (SEM) and specific surface area studies are performed using Brunauer-Emmet-Teller (BET) method. XRD studies show that multiphase structures are obtained as a result of 1h sintering at 700-1200 °C for both pure bone and TiO2-bone composite materials. The factors affecting the transport of different heavy metal ions through the selected membranes are determined from permeation flux measurements. It is found that membrane pore size, membrane surface roughness and membrane surface charge are the key parameters that control the transport or rejection of heavy metal ions through the selected membranes.

Post-Fire Recovery in Coastal Sage Scrub: Seed Rain and Community Trajectory.

PubMed

Conlisk, Erin; Swab, Rebecca; Martínez-Berdeja, Alejandra; Daugherty, Matthew P

2016-01-01

Disturbance is a primary mechanism structuring ecological communities. However, human activity has the potential to alter the frequency and intensity of natural disturbance regimes, with subsequent effects on ecosystem processes. In Southern California, human development has led to increased fire frequency close to urban areas that can form a positive feedback with invasive plant spread. Understanding how abiotic and biotic factors structure post-fire plant communities is a critical component of post-fire management and restoration. In this study we considered a variety of mechanisms affecting post-fire vegetation recovery in Riversidean sage scrub. Comparing recently burned plots to unburned plots, we found that burning significantly reduced species richness and percent cover of exotic vegetation the first two years following a 100-hectare wildfire. Seed rain was higher in burned plots, with more native forb seeds, while unburned plots had more exotic grass seeds. Moreover, there were significant correlations between seed rain composition and plant cover composition the year prior and the year after. Collectively, this case study suggests that fire can alter community composition, but there was not compelling evidence of a vegetation-type conversion. Instead, the changes in the community composition were temporary and convergence in community composition was apparent within two years post-fire.

Consumers’ Attitude Towards Fish Meat

PubMed Central

Passantino, Annamaria; Longo, Sabrina; Voslářová, Eva

2014-01-01

The overall aim of this paper is to show the factors that may affect consumers’ attitude towards farmed fish products. Consumers ask new products on the basis of different quality attributes: stability, safety, composition, better health effects, environment protection, etc. Different and controversial opinions on farmed and wild fish are also explored by literature review. The authors pay attention also to fish welfare as an emerging issue and effective information about fish products as a factor exerting a positive influence on consumers’ decision of purchase. Some relevant legislative notes on the paper’s topics are also cited. The qualitative aspects of aquaculture fish and the consumers’ demand and choice need further studies, according to some factors, such as the changing consumers’ attitudes towards fish products, the different fish quality perception and the development in the aquaculture systems. PMID:27800359

40 CFR 63.5795 - How do I know if my reinforced plastic composites production facility is a new affected source or...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 12 2011-07-01 2009-07-01 true How do I know if my reinforced plastic... for Hazardous Air Pollutants: Reinforced Plastic Composites Production What This Subpart Covers § 63.5795 How do I know if my reinforced plastic composites production facility is a new affected source or...

40 CFR 63.5795 - How do I know if my reinforced plastic composites production facility is a new affected source or...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 13 2013-07-01 2012-07-01 true How do I know if my reinforced plastic... Emissions Standards for Hazardous Air Pollutants: Reinforced Plastic Composites Production What This Subpart Covers § 63.5795 How do I know if my reinforced plastic composites production facility is a new affected...

40 CFR 63.5795 - How do I know if my reinforced plastic composites production facility is a new affected source or...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 13 2014-07-01 2014-07-01 false How do I know if my reinforced plastic... Emissions Standards for Hazardous Air Pollutants: Reinforced Plastic Composites Production What This Subpart Covers § 63.5795 How do I know if my reinforced plastic composites production facility is a new affected...

40 CFR 63.5795 - How do I know if my reinforced plastic composites production facility is a new affected source or...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 13 2012-07-01 2012-07-01 false How do I know if my reinforced plastic... Emissions Standards for Hazardous Air Pollutants: Reinforced Plastic Composites Production What This Subpart Covers § 63.5795 How do I know if my reinforced plastic composites production facility is a new affected...

Probabilistic Micromechanics and Macromechanics for Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Murthy, Pappu L. N.; Mital, Subodh K.; Shah, Ashwin R.

1997-01-01

The properties of ceramic matrix composites (CMC's) are known to display a considerable amount of scatter due to variations in fiber/matrix properties, interphase properties, interphase bonding, amount of matrix voids, and many geometry- or fabrication-related parameters, such as ply thickness and ply orientation. This paper summarizes preliminary studies in which formal probabilistic descriptions of the material-behavior- and fabrication-related parameters were incorporated into micromechanics and macromechanics for CMC'S. In this process two existing methodologies, namely CMC micromechanics and macromechanics analysis and a fast probability integration (FPI) technique are synergistically coupled to obtain the probabilistic composite behavior or response. Preliminary results in the form of cumulative probability distributions and information on the probability sensitivities of the response to primitive variables for a unidirectional silicon carbide/reaction-bonded silicon nitride (SiC/RBSN) CMC are presented. The cumulative distribution functions are computed for composite moduli, thermal expansion coefficients, thermal conductivities, and longitudinal tensile strength at room temperature. The variations in the constituent properties that directly affect these composite properties are accounted for via assumed probabilistic distributions. Collectively, the results show that the present technique provides valuable information about the composite properties and sensitivity factors, which is useful to design or test engineers. Furthermore, the present methodology is computationally more efficient than a standard Monte-Carlo simulation technique; and the agreement between the two solutions is excellent, as shown via select examples.

Development of permanent magnet MnAlC/polymer composites and flexible filament for bonding and 3D-printing technologies

PubMed Central

Rial, Javier; de Vicente, Javier; Skårman, Björn; Vidarsson, Hilmar; Larsson, Per-Olof

2018-01-01

Abstract Searching for high-performance permanent magnets components with no limitation in shape and dimensions is highly desired to overcome the present design and manufacturing restrictions, which affect the efficiency of the final devices in energy, automotive and aerospace sectors. Advanced 3D-printing of composite materials and related technologies is an incipient route to achieve functional structures avoiding the limitations of traditional manufacturing. Gas-atomized MnAlC particles combined with polymer have been used in this work for fabricating scalable rare earth-free permanent magnet composites and extruded flexible filaments with continuous length exceeding 10 m. Solution casting has been used to synthesize homogeneous composites with tuned particles content, made of a polyethylene (PE) matrix embedding quasi-spherical particles of the ferromagnetic τ-MnAlC phase. A maximum filling factor of 86.5 and 72.3% has been obtained for the composite and the filament after extrusion, respectively. The magnetic measurements reveal no deterioration of the properties of the MnAlC particles after the composite synthesis and filament extrusion. The produced MnAlC/PE materials will serve as precursors for an efficient and scalable design and fabrication of end-products by different processing techniques (polymerized cold-compacted magnets and 3D-printing, respectively) in view of technological applications (from micro electromechanical systems to energy and transport applications). PMID:29887921

Development and Sliding Wear Response of Epoxy Composites Filled with Coal Mine Overburden Material

NASA Astrophysics Data System (ADS)

Das, Prithika; Satapathy, Alok; Mishra, M. K.

2018-03-01

The paper reports on development and characterization of epoxy based composites filled with micro-sized mine overburden material. Coal mine overburden material is typically highly heterogeneous and is considered as waste material. For excavating each ton of coal, roughly 5 tons of overburden materials are removed and is dumped nearby occupying large space. Gainful utilization of this waste is a major challenge. In the present work, this material is used as filler materials in making a new class of epoxy matrix composites. Composites with different weight proportions of fillers (0, 10, 20, 30 and 40) wt. % are prepared by hand layup technique. Compression tests are performed as per corresponding ASTM standards to assess the compressive strength of these composites. Further, dry sliding tests are performed following ASTM G99 standards using a pin on disk machine. A design of experiment approach based on Taguchi’s L16 orthogonal arrays is adopted. Tests are performed at different sliding velocities for multiple sliding distances under varying normal loads. Specific wear rates of the composites under different test conditions are obtained. The analysis of the test results revealed that the filler content and the sliding velocity are the most predominant control factors affecting the wear rate. This work thus, opens up a new avenue for the value added utilization of coal mine overburden material.

Development of permanent magnet MnAlC/polymer composites and flexible filament for bonding and 3D-printing technologies.

PubMed

Palmero, Ester M; Rial, Javier; de Vicente, Javier; Camarero, Julio; Skårman, Björn; Vidarsson, Hilmar; Larsson, Per-Olof; Bollero, Alberto

2018-01-01

Searching for high-performance permanent magnets components with no limitation in shape and dimensions is highly desired to overcome the present design and manufacturing restrictions, which affect the efficiency of the final devices in energy, automotive and aerospace sectors. Advanced 3D-printing of composite materials and related technologies is an incipient route to achieve functional structures avoiding the limitations of traditional manufacturing. Gas-atomized MnAlC particles combined with polymer have been used in this work for fabricating scalable rare earth-free permanent magnet composites and extruded flexible filaments with continuous length exceeding 10 m. Solution casting has been used to synthesize homogeneous composites with tuned particles content, made of a polyethylene (PE) matrix embedding quasi-spherical particles of the ferromagnetic τ -MnAlC phase. A maximum filling factor of 86.5 and 72.3% has been obtained for the composite and the filament after extrusion, respectively. The magnetic measurements reveal no deterioration of the properties of the MnAlC particles after the composite synthesis and filament extrusion. The produced MnAlC/PE materials will serve as precursors for an efficient and scalable design and fabrication of end-products by different processing techniques (polymerized cold-compacted magnets and 3D-printing, respectively) in view of technological applications (from micro electromechanical systems to energy and transport applications).

Combined Homogeneous Surface Diffusion Model - Design of experiments approach to optimize dye adsorption considering both equilibrium and kinetic aspects.

PubMed

Muthukkumaran, A; Aravamudan, K

2017-12-15

Adsorption, a popular technique for removing azo dyes from aqueous streams, is influenced by several factors such as pH, initial dye concentration, temperature and adsorbent dosage. Any strategy that seeks to identify optimal conditions involving these factors, should take into account both kinetic and equilibrium aspects since they influence rate and extent of removal by adsorption. Hence rigorous kinetics and accurate equilibrium models are required. In this work, the experimental investigations pertaining to adsorption of acid orange 10 dye (AO10) on activated carbon were carried out using Central Composite Design (CCD) strategy. The significant factors that affected adsorption were identified to be solution temperature, solution pH, adsorbent dosage and initial solution concentration. Thermodynamic analysis showed the endothermic nature of the dye adsorption process. The kinetics of adsorption has been rigorously modeled using the Homogeneous Surface Diffusion Model (HSDM) after incorporating the non-linear Freundlich adsorption isotherm. Optimization was performed for kinetic parameters (color removal time and surface diffusion coefficient) as well as the equilibrium affected response viz. percentage removal. Finally, the optimum conditions predicted were experimentally validated. Copyright © 2017 Elsevier Ltd. All rights reserved.

Habitat connectivity and in-stream vegetation control temporal variability of benthic invertebrate communities.

PubMed

Huttunen, K-L; Mykrä, H; Oksanen, J; Astorga, A; Paavola, R; Muotka, T

2017-05-03

One of the key challenges to understanding patterns of β diversity is to disentangle deterministic patterns from stochastic ones. Stochastic processes may mask the influence of deterministic factors on community dynamics, hindering identification of the mechanisms causing variation in community composition. We studied temporal β diversity (among-year dissimilarity) of macroinvertebrate communities in near-pristine boreal streams across 14 years. To assess whether the observed β diversity deviates from that expected by chance, and to identify processes (deterministic vs. stochastic) through which different explanatory factors affect community variability, we used a null model approach. We observed that at the majority of sites temporal β diversity was low indicating high community stability. When stochastic variation was unaccounted for, connectivity was the only variable explaining temporal β diversity, with weakly connected sites exhibiting higher community variability through time. After accounting for stochastic effects, connectivity lost importance, suggesting that it was related to temporal β diversity via random colonization processes. Instead, β diversity was best explained by in-stream vegetation, community variability decreasing with increasing bryophyte cover. These results highlight the potential of stochastic factors to dampen the influence of deterministic processes, affecting our ability to understand and predict changes in biological communities through time.

Effects of Abiotic Factors on HIPV-Mediated Interactions between Plants and Parasitoids

PubMed Central

Becker, Christine; Desneux, Nicolas; Monticelli, Lucie; Fernandez, Xavier; Michel, Thomas; Lavoir, Anne-Violette

2015-01-01

In contrast to constitutively emitted plant volatiles (PV), herbivore-induced plant volatiles (HIPV) are specifically emitted by plants when afflicted with herbivores. HIPV can be perceived by parasitoids and predators which parasitize or prey on the respective herbivores, including parasitic hymenoptera. HIPV act as signals and facilitate host/prey detection. They comprise a blend of compounds: main constituents are terpenoids and “green leaf volatiles.” Constitutive emission of PV is well known to be influenced by abiotic factors like temperature, light intensity, water, and nutrient availability. HIPV share biosynthetic pathways with constitutively emitted PV and might therefore likewise be affected by abiotic conditions. However, the effects of abiotic factors on HIPV-mediated biotic interactions have received only limited attention to date. HIPV being influenced by the plant's growing conditions could have major implications for pest management. Quantitative and qualitative changes in HIPV blends may improve or impair biocontrol. Enhanced emission of HIPV may attract a larger number of natural enemies. Reduced emission rates or altered compositions, however, may render blends imperceptible to parasitoides and predators. Predicting the outcome of these changes is highly important for food production and for ecosystems affected by global climate change. PMID:26788501

Analytical method development of nifedipine and its degradants binary mixture using high performance liquid chromatography through a quality by design approach

NASA Astrophysics Data System (ADS)

Choiri, S.; Ainurofiq, A.; Ratri, R.; Zulmi, M. U.

2018-03-01

Nifedipin (NIF) is a photo-labile drug that easily degrades when it exposures a sunlight. This research aimed to develop of an analytical method using a high-performance liquid chromatography and implemented a quality by design approach to obtain effective, efficient, and validated analytical methods of NIF and its degradants. A 22 full factorial design approach with a curvature as a center point was applied to optimize of the analytical condition of NIF and its degradants. Mobile phase composition (MPC) and flow rate (FR) as factors determined on the system suitability parameters. The selected condition was validated by cross-validation using a leave one out technique. Alteration of MPC affected on time retention significantly. Furthermore, an increase of FR reduced the tailing factor. In addition, the interaction of both factors affected on an increase of the theoretical plates and resolution of NIF and its degradants. The selected analytical condition of NIF and its degradants has been validated at range 1 – 16 µg/mL that had good linearity, precision, accuration and efficient due to an analysis time within 10 min.

What controls the stable isotope composition of precipitation in the Mekong Delta? A model-based statistical approach

NASA Astrophysics Data System (ADS)

Le Duy, Nguyen; Heidbüchel, Ingo; Meyer, Hanno; Merz, Bruno; Apel, Heiko

2018-02-01

This study analyzes the influence of local and regional climatic factors on the stable isotopic composition of rainfall in the Vietnamese Mekong Delta (VMD) as part of the Asian monsoon region. It is based on 1.5 years of weekly rainfall samples. In the first step, the isotopic composition of the samples is analyzed by local meteoric water lines (LMWLs) and single-factor linear correlations. Additionally, the contribution of several regional and local factors is quantified by multiple linear regression (MLR) of all possible factor combinations and by relative importance analysis. This approach is novel for the interpretation of isotopic records and enables an objective quantification of the explained variance in isotopic records for individual factors. In this study, the local factors are extracted from local climate records, while the regional factors are derived from atmospheric backward trajectories of water particles. The regional factors, i.e., precipitation, temperature, relative humidity and the length of backward trajectories, are combined with equivalent local climatic parameters to explain the response variables δ18O, δ2H, and d-excess of precipitation at the station of measurement. The results indicate that (i) MLR can better explain the isotopic variation in precipitation (R2 = 0.8) compared to single-factor linear regression (R2 = 0.3); (ii) the isotopic variation in precipitation is controlled dominantly by regional moisture regimes (˜ 70 %) compared to local climatic conditions (˜ 30 %); (iii) the most important climatic parameter during the rainy season is the precipitation amount along the trajectories of air mass movement; (iv) the influence of local precipitation amount and temperature is not significant during the rainy season, unlike the regional precipitation amount effect; (v) secondary fractionation processes (e.g., sub-cloud evaporation) can be identified through the d-excess and take place mainly in the dry season, either locally for δ18O and δ2H, or along the air mass trajectories for d-excess. The analysis shows that regional and local factors vary in importance over the seasons and that the source regions and transport pathways, and particularly the climatic conditions along the pathways, have a large influence on the isotopic composition of rainfall. Although the general results have been reported qualitatively in previous studies (proving the validity of the approach), the proposed method provides quantitative estimates of the controlling factors, both for the whole data set and for distinct seasons. Therefore, it is argued that the approach constitutes an advancement in the statistical analysis of isotopic records in rainfall that can supplement or precede more complex studies utilizing atmospheric models. Due to its relative simplicity, the method can be easily transferred to other regions, or extended with other factors. The results illustrate that the interpretation of the isotopic composition of precipitation as a recorder of local climatic conditions, as for example performed for paleorecords of water isotopes, may not be adequate in the southern part of the Indochinese Peninsula, and likely neither in other regions affected by monsoon processes. However, the presented approach could open a pathway towards better and seasonally differentiated reconstruction of paleoclimates based on isotopic records.

Factors affecting reproducibility between genome-scale siRNA-based screens

PubMed Central

Barrows, Nicholas J.; Le Sommer, Caroline; Garcia-Blanco, Mariano A.; Pearson, James L.

2011-01-01

RNA interference-based screening is a powerful new genomic technology which addresses gene function en masse. To evaluate factors influencing hit list composition and reproducibility, we performed two identically designed small interfering RNA (siRNA)-based, whole genome screens for host factors supporting yellow fever virus infection. These screens represent two separate experiments completed five months apart and allow the direct assessment of the reproducibility of a given siRNA technology when performed in the same environment. Candidate hit lists generated by sum rank, median absolute deviation, z-score, and strictly standardized mean difference were compared within and between whole genome screens. Application of these analysis methodologies within a single screening dataset using a fixed threshold equivalent to a p-value ≤ 0.001 resulted in hit lists ranging from 82 to 1,140 members and highlighted the tremendous impact analysis methodology has on hit list composition. Intra- and inter-screen reproducibility was significantly influenced by the analysis methodology and ranged from 32% to 99%. This study also highlighted the power of testing at least two independent siRNAs for each gene product in primary screens. To facilitate validation we conclude by suggesting methods to reduce false discovery at the primary screening stage. In this study we present the first comprehensive comparison of multiple analysis strategies, and demonstrate the impact of the analysis methodology on the composition of the “hit list”. Therefore, we propose that the entire dataset derived from functional genome-scale screens, especially if publicly funded, should be made available as is done with data derived from gene expression and genome-wide association studies. PMID:20625183

Expanding the Reach of Participatory Risk Management: Testing an Online Decision-Aiding Framework for Informing Internally Consistent Choices.

PubMed

Bessette, Douglas L; Campbell-Arvai, Victoria; Arvai, Joseph

2016-05-01

This article presents research aimed at developing and testing an online, multistakeholder decision-aiding framework for informing multiattribute risk management choices associated with energy development and climate change. The framework was designed to provide necessary background information and facilitate internally consistent choices, or choices that are in line with users' prioritized objectives. In order to test different components of the decision-aiding framework, a six-part, 2 × 2 × 2 factorial experiment was conducted, yielding eight treatment scenarios. The three factors included: (1) whether or not users could construct their own alternatives; (2) the level of detail regarding the composition of alternatives users would evaluate; and (3) the way in which a final choice between users' own constructed (or highest-ranked) portfolio and an internally consistent portfolio was presented. Participants' self-reports revealed the framework was easy to use and providing an opportunity to develop one's own risk-management alternatives (Factor 1) led to the highest knowledge gains. Empirical measures showed the internal consistency of users' decisions across all treatments to be lower than expected and confirmed that providing information about alternatives' composition (Factor 2) resulted in the least internally consistent choices. At the same time, those users who did not develop their own alternatives and were not shown detailed information about the composition of alternatives believed their choices to be the most internally consistent. These results raise concerns about how the amount of information provided and the ability to construct alternatives may inversely affect users' real and perceived internal consistency. © 2015 Society for Risk Analysis.

Floral and nesting resources, habitat structure, and fire influence bee distribution across an open-forest gradient

USGS Publications Warehouse

Grundel, R.; Jean, R.P.; Frohnapple, K.J.; Glowacki, G.A.; Scott, P.E.; Pavlovic, N.B.

2010-01-01

Given bees' central effect on vegetation communities, it is important to understand how and why bee distributions vary across ecological gradients. We examined how plant community composition, plant diversity, nesting suitability, canopy cover, land use, and fire history affected bee distribution across an open-forest gradient in northwest Indiana, USA, a gradient similar to the historic Midwest United States landscape mosaic. When considered with the other predictors, plant community composition was not a significant predictor of bee community composition. Bee abundance was negatively related to canopy cover and positively to recent fire frequency, bee richness was positively related to plant richness and abundance of potential nesting resources, and bee community composition was significantly related to plant richness, soil characteristics potentially related to nesting suitability, and canopy cover. Thus, bee abundance was predicted by a different set of environmental characteristics than was bee species richness, and bee community composition was predicted, in large part, by a combination of the significant predictors of bee abundance and richness. Differences in bee community composition along the woody vegetation gradient were correlated with relative abundance of oligolectic, or diet specialist, bees. Because oligoleges were rarer than diet generalists and were associated with open habitats, their populations may be especially affected by degradation of open habitats. More habitat-specialist bees were documented for open and forest/scrub habitats than for savanna/woodland habitats, consistent with bees responding to habitats of intermediate woody vegetation density, such as savannas, as ecotones rather than as distinct habitat types. Similarity of bee community composition, similarity of bee abundance, and similarity of bee richness between sites were not significantly related to proximity of sites to each other. Nestedness analysis indicated that species composition in species-poor sites was not merely a subset of species composition at richer sites. The lack of significant proximity or nestedness effects suggests that factors at a small spatial scale strongly influence bees' use of sites. The findings indicate that patterns of plant diversity, nesting resource availability, recent fire, and habitat shading, present at the scale of a few hundred meters, are key determinants of bee community patterns in the mosaic open-savanna-forest landscape. ?? 2010 by the Ecological Society of America.

Nitrogen-to-Protein Conversion Factors for Crop Residues and Animal Manure Common in China.

PubMed

Chen, Xueli; Zhao, Guanglu; Zhang, Yang; Han, Lujia; Xiao, Weihua

2017-10-25

Accurately determining protein content is essential in exploiting biomass as feed and fuel. A survey of biomass samples in China indicated protein contents from 2.65 to 3.98% for crop residues and from 6.07 to 10.24% for animal manure of dry basis. Conversion factors based on amino acid nitrogen (k A ) ranged from 5.42 to 6.00 for the former and from 4.78 to 5.36 for the latter, indicating that the traditional factor of 6.25 is not suitable for biomass samples. On the other hand, conversion factors from Kjeldahl nitrogen (k P ) ranged from 3.97 to 4.57 and from 2.76 to 4.31 for crop residues and animal manure, respectively. Of note, conversion factors were strongly affected by amino acid composition and levels of nonprotein nitrogen. Thus, k P values of 4.23 for crop residues, 4.11 for livestock manure, and 3.11 for poultry manure are recommended to better estimate protein content from total nitrogen.

Atmospheric Composition Change: Climate-Chemistry Interactions

NASA Technical Reports Server (NTRS)

Isaksen, I.S.A.; Granier, C.; Myhre, G.; Bernsten, T. K.; Dalsoren, S. B.; Gauss, S.; Klimont, Z.; Benestad, R.; Bousquet, P.; Collins, W.;

Controlled release of tocopherols from polymer blend films

NASA Astrophysics Data System (ADS)

Obinata, Noe

Controlled release packaging has great potential to increase storage stability of foods by releasing active compounds into foods continuously over time. However, a major limitation in development of this technology is the inability to control the release and provide rates useful for long term storage of foods. Better understanding of the factors affecting active compound release is needed to overcome this limitation. The objective of this research was to investigate the relationship between polymer composition, polymer processing method, polymer morphology, and release properties of active compounds, and to provide proof of principle that compound release is controlled by film morphology. A natural antioxidant, tocopherol was used as a model active compound because it is natural, effective, heat stable, and soluble in most packaging polymers. Polymer blend films were produced from combination of linear low density polyethylene (LLDPE) and high density polyethylene (HDPE), polypropylene (PP), or polystyrene (PS) with 3000 ppm mixed tocopherols using conventional blending method and innovative blending method, smart blending with a novel mixer using chaotic advection. Film morphologies were visualized with scanning electron microscopy (SEM). Release of tocopherols into 95% ethanol as a food simulant was measured by UV/Visible spectrophotometry or HPLC, and diffusivity of tocopherols in the polymers was estimated from this data. Polymer composition (blend proportions) and processing methods have major effects on film morphology. Four different types of morphologies, dispersed, co-continuous, fiber, and multilayer structures were developed by either conventional extrusion or smart blending. With smart blending of fixed polymer compositions, different morphologies were progressively developed with fixed polymer composition as the number of rod rotations increased, providing a way to separate effects of polymer composition and morphology. The different morphologies obtained using conventional and smart blending greatly affected tocopherol release. Strong correlation was observed between morphology and release rate: multilayer, slow release; co-continuous and fiber, moderate; disperse: fast release. Results indicate that morphology can be manipulated by polymer composition and processing method, and release rates of tocopherols are varied with polymer morphology. Manipulating polymer compositions and film morphologies may provide a means to control the release of tocopherols from food contact films.

Rare earth elements concentration in mushroom cultivation substrates affects the production process and fruit-bodies content of Pleurotus ostreatus and Cyclocybe cylindracea.

PubMed

Koutrotsios, Georgios; Danezis, Georgios P; Georgiou, Constantinos A; Zervakis, Georgios I

2018-04-20

Concentrations of 16 rare earth elements (REEs) and two actinides were determined for the first time both in cultivated mushrooms and in their production substrates by inductively coupled plasma mass spectroscopy. Moreover, the effect of REEs on cultivation parameters and composition of the final product was assessed, together with their potential use for authentication purposes. The concentrations of REEs varied greatly among seven cultivation substrates and correlated with measurements in Cyclocybe cylindracea mushrooms; no such correlation was established in Pleurotus ostreatus. Reduction of hemicellulose, cellulose, and lignin in substrates during P. ostreatus cultivation was positively correlated with REE concentrations, which also affected the production performance depending on the species examined. In all cases, a negative correlation was established between bioconcentration factors (BCF) in mushrooms and REE content in substrates, while the effect of substrate composition on BCF values varied according to the element studied. The estimated daily intake values of REEs through mushroom consumption was at much lower levels than those reported as potentially harmful for human health. The content of REEs in cultivation substrates and in mushrooms revealed that the bioaccumulation of elements differed in each fungus. The nature/origin of substrates seemed to affect the concentration of REEs in mushrooms to a considerable extent. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Application of Granulated Blast Furnace Slag in Cement Composites Exposed to Biogenic Acid Attack

NASA Astrophysics Data System (ADS)

Kovalcikova, M.; Estokova, A.; Luptakova, A.

2015-11-01

The deterioration of cement-based materials used for the civil infrastructure has led to the realization that cement-based materials, such as concrete, must be improved in terms of their properties and durability. Leaching of calcium ions increases the porosity of cement- based materials, consequently resulting in a negative effect on durability since it provides an entry for aggressive harmful ions, causing corrosion of concrete. The use supplementary cementing composite materials have been reported to improve the resistance of concrete to deterioration by aggressive chemicals. The paper is focused on the investigation of the influence of biogenic acid attack on the cement composites affected by bacteria Acidithiobacillus thiooxidans. The concrete specimens with 65 wt. % addition of antimicrobial activated granulated blast furnace slag as durability increasing factor as well as without any addition were studied. The experiments proceeded during 150 days under model laboratory conditions. The pH values and chemical composition of leachates were measured after each 30- day cycle. The calcium and silicon contents in leachates were evaluated using X - ray fluorescence method (XRF). Summarizing the results, the 65% wt. addition of antimicrobial activated granulated blast furnace slag was not confirmed to be more resistant.

New Therapeutic Drugs from Bioactive Natural Molecules: the Role of Gut Microbiota Metabolism in Neurodegenerative Diseases.

PubMed

Di Meo, Francesco; Donato, Stella; Di Pardo, Alba; Maglione, Vittorio; Filosa, Stefania; Crispi, Stefania

2018-04-03

The gut-brain axis is considered a neuroendocrine system, which connects brain and gastrointestinal tract and plays an important role in stress response. The homeostasis of gut-brain axis is important for healthy conditions and its alterations are associated to neurological disorders and neurodegenerative diseases. Gut microbiota is a dynamic ecosystem that can be altered by external factors such as diet composition, antibiotics or xenobiotics. Recent advances in gut microbiota analyses indicate that the gut bacterial community plays a key role in maintaining normal brain functions. Recent metagenomic analyses have elucidated that the relationship between gut and brain, either in normal or in pathological conditions, reflects the existence of a "microbiota-gut-brain" axis. Gut microbiota composition can be influenced by dietary ingestion of probiotics or natural bioactive molecules such as prebiotics and polyphenols. Their derivatives coming from microbiota metabolism can affect both gut bacterial composition and brain biochemistry. Modifications of microbiota composition by natural bioactive molecules could be used to restore the altered brain functions, which characterize neurodegenerative diseases, leading to consider these compounds as novel therapeutic strategies for the treatment of neuropathologies. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Body composition among HIV-seropositive and HIV-seronegative adult patients with pulmonary tuberculosis in Uganda.

PubMed

Mupere, Ezekiel; Zalwango, Sarah; Chiunda, Allan; Okwera, Alphonse; Mugerwa, Roy; Whalen, Christopher

2010-03-01

We determined whether human immunodeficiency virus (HIV) infection affects body cell mass and fat mass wasting among adults with pulmonary tuberculosis (PTB). We screened 967 Ugandan adults for PTB and HIV infection in a cross-sectional study. We compared anthropometric and bioelectric impedance analysis (BIA) body composition parameters among HIV-seropositive and HIV-seronegative men and women with or without PTB by using a non-parametric test. We found that poor nutritional status associated with TB differed among men and women. Anthropometric and BIA body composition did not differ between HIV-seropositive and HIV-seronegative patients regardless of gender. Average weight group difference in men consisted of body cell mass and fat mass in equal proportions of 43%. In women, average weight group difference consisted predominantly of fat mass of 73% and body cell mass of 13%. Compared to individuals without TB, patients with TB had lower body mass index, weight, body cell mass, and fat mass regardless of gender and HIV status. Gender, but not HIV status, was associated with body composition changes in TB. TB appears to be the dominant factor driving the wasting process among co-infected patients. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Body Composition among HIV-seropositive and HIV-seronegative Adult Patients with Pulmonary Tuberculosis in Uganda

PubMed Central

Mupere, Ezekiel; Zalwango, Sarah; Chiunda, Allan; Okwera, Alphonse; Mugerwa, Roy; Whalen, Christopher

2009-01-01

Purpose We determined whether human immunodeficiency virus (HIV) infection affects body cell mass and fat mass wasting among adults with pulmonary tuberculosis (PTB). Methods We screened 967 Ugandan adults for PTB and HIV infection in a cross-sectional study. We compared anthropometric and bioelectric impedance analysis (BIA) body composition parameters among HIV-seropositive and HIV-seronegative men and women with or without PTB using a non-parametric test. Results We found that poor nutritional status associated with TB differed among men and women. Anthropometric and BIA body composition did not differ between HIV-seropositive and HIV-seronegative patients regardless of gender. Average weight group difference in men comprised of body cell mass and fat mass in equal proportions of 43%. In women, average weight group difference comprised predominantly of fat mass of 73% and body cell mass of 13%. Compared to individuals without TB, patients with TB had lower body mass index, weight, body cell mass, and fat mass regardless of gender and HIV status. Conclusions Gender but not HIV status was associated with body composition changes in TB. Tuberculosis appears to be the dominant factor driving the wasting process among co-infected patients. PMID:20159491

Determining the composition of small features in atom probe: bcc Cu-rich precipitates in an Fe-rich matrix.

PubMed

Morley, A; Sha, G; Hirosawa, S; Cerezo, A; Smith, G D W

2009-04-01

Aberrations in the ion trajectories near the specimen surface are an important factor in the spatial resolution of the atom probe technique. Near the boundary between two phases with dissimilar evaporation fields, ion trajectory overlaps may occur, leading to a biased measurement of composition in the vicinity of this interface. In the case of very small second-phase precipitates, the region affected by trajectory overlaps may extend to the centre of the precipitate prohibiting a direct measurement of composition. A method of quantifying the aberrant matrix contribution and thus estimating the underlying composition is presented. This method is applied to the Fe-Cu-alloy system, where the precipitation of low-nanometre size Cu-rich precipitates is of considerable technical importance in a number of materials applications. It is shown definitively that there is a non-zero underlying level of Fe within precipitates formed upon thermal ageing, which is augmented and masked by trajectory overlaps. The concentration of Fe in the precipitate phase is shown to be a function of ageing temperature. An estimate of the underlying Fe level is made, which is at lower levels than commonly reported by atom probe investigations.

Soil biodiversity and soil community composition determine ecosystem multifunctionality

PubMed Central

Wagg, Cameron; Bender, S. Franz; Widmer, Franco; van der Heijden, Marcel G. A.

2014-01-01

Biodiversity loss has become a global concern as evidence accumulates that it will negatively affect ecosystem services on which society depends. So far, most studies have focused on the ecological consequences of above-ground biodiversity loss; yet a large part of Earth’s biodiversity is literally hidden below ground. Whether reductions of biodiversity in soil communities below ground have consequences for the overall performance of an ecosystem remains unresolved. It is important to investigate this in view of recent observations that soil biodiversity is declining and that soil communities are changing upon land use intensification. We established soil communities differing in composition and diversity and tested their impact on eight ecosystem functions in model grassland communities. We show that soil biodiversity loss and simplification of soil community composition impair multiple ecosystem functions, including plant diversity, decomposition, nutrient retention, and nutrient cycling. The average response of all measured ecosystem functions (ecosystem multifunctionality) exhibited a strong positive linear relationship to indicators of soil biodiversity, suggesting that soil community composition is a key factor in regulating ecosystem functioning. Our results indicate that changes in soil communities and the loss of soil biodiversity threaten ecosystem multifunctionality and sustainability. PMID:24639507

Sire carcass breeding values affect body composition in lambs--2. Effects on fat and bone weight and their distribution within the carcass as measured by computed tomography.

PubMed

Anderson, F; Williams, A; Pannier, L; Pethick, D W; Gardner, G E

2016-06-01

This study assessed the effect of paternal Australian Sheep Breeding Values for post weaning c-site eye muscle depth (PEMD) and fat depth (PFAT), and post weaning weight (PWWT) on the composition of lamb carcasses. Composition was measured using computed tomography scans of 1665 lambs which were progeny of 85 Maternal, 115 Merino and 155 Terminal sires. Reducing sire PFAT decreased carcass fat weight by 4.8% and increased carcass bone by 1.3% per unit of PFAT (range 5.1 mm). Increasing sire PEMD reduced carcass fat weight by 3.8% in Maternal and 2% in Terminal sired lambs per unit of PEMD (range 4.3 and 7.8 mm), with no impact on bone. Increasing sire PWWT reduced carcass fat weight, but only at some experimental locations. Differences in composition varied between sire types with Maternal sired lambs having the most fat and Merino sired lambs the greatest bone weight. Genetic effects on fatness were greater than the environmental or production factor effects, with the converse true of bone. Copyright © 2016 Elsevier Ltd. All rights reserved.

Human activities cause distinct dissolved organic matter composition across freshwater ecosystems.

PubMed

Williams, Clayton J; Frost, Paul C; Morales-Williams, Ana M; Larson, James H; Richardson, William B; Chiandet, Aisha S; Xenopoulos, Marguerite A

2016-02-01

Dissolved organic matter (DOM) composition in freshwater ecosystems is influenced by the interactions among physical, chemical, and biological processes that are controlled, at one level, by watershed landscape, hydrology, and their connections. Against this environmental template, humans may strongly influence DOM composition. Yet, we lack a comprehensive understanding of DOM composition variation across freshwater ecosystems differentially affected by human activity. Using optical properties, we described DOM variation across five ecosystem groups of the Laurentian Great Lakes region: large lakes, Kawartha Lakes, Experimental Lakes Area, urban stormwater ponds, and rivers (n = 184 sites). We determined how between ecosystem variation in DOM composition related to watershed size, land use and cover, water quality measures (conductivity, dissolved organic carbon (DOC), nutrient concentration, chlorophyll a), and human population density. The five freshwater ecosystem groups had distinctive DOM composition from each other. These significant differences were not explained completely through differences in watershed size nor spatial autocorrelation. Instead, multivariate partial least squares regression showed that DOM composition was related to differences in human impact across freshwater ecosystems. In particular, urban/developed watersheds with higher human population densities had a unique DOM composition with a clear anthropogenic influence that was distinct from DOM composition in natural land cover and/or agricultural watersheds. This nonagricultural, human developed impact on aquatic DOM was most evident through increased levels of a microbial, humic-like parallel factor analysis component (C6). Lotic and lentic ecosystems with low human population densities had DOM compositions more typical of clear water to humic-rich freshwater ecosystems but C6 was only present at trace to background levels. Consequently, humans are strongly altering the quality of DOM in waters nearby or flowing through highly populated areas, which may alter carbon cycles in anthropogenically disturbed ecosystems at broad scales. © 2015 John Wiley & Sons Ltd.

Human activities cause distinct dissolved organic matter composition across freshwater ecosystems

USGS Publications Warehouse

Williams, Clayton J.; Frost, Paul C.; Morales-Williams, Ana M.; Larson, James H.; Richardson, William B.; Chiandet, Aisha S.; Xenopoulos, Marguerite A.

2016-01-01

Dissolved organic matter (DOM) composition in freshwater ecosystems is influenced by interactions between physical, chemical, and biological processes that are controlled, at one level, by watershed landscape, hydrology, and their connections. Against this environmental template, humans may strongly influence DOM composition. Yet, we lack a comprehensive understanding of DOM composition variation across freshwater ecosystems differentially affected by human activity. Using optical properties, we described DOM variation across five ecosystem groups of the Laurentian Great Lakes Region: large lakes, Kawartha Lakes, Experimental Lakes Area, urban stormwater ponds, and rivers (n = 184 sites). We determined how between ecosystem variation in DOM composition related to watershed size, land use and cover, water quality measures (conductivity, dissolved organic carbon (DOC), nutrient concentration, chlorophyll a), and human population density. The five freshwater ecosystem groups had distinctive DOM composition from each other. These significant differences were not explained completely through differences in watershed size nor spatial autocorrelation. Instead, multivariate partial least squares regression showed that DOM composition was related to differences in human impact across freshwater ecosystems. In particular, urban/developed watersheds with higher human population densities had a unique DOM composition with a clear anthropogenic influence that was distinct from DOM composition in natural land cover and/or agricultural watersheds. This nonagricultural, human developed impact on aquatic DOM was most evident through increased levels of a microbial, humic-like parallel factor analysis component (C6). Lotic and lentic ecosystems with low human population densities had DOM compositions more typical of clear water to humic-rich freshwater ecosystems but C6 was only present at trace to background levels. Consequently, humans are strongly altering the quality of DOM in waters nearby or flowing through highly populated areas, which may alter carbon cycles in anthropogenically disturbed ecosystems at broad scales.

Medium range order and structural relaxation in As–Se network glasses through FSDP analysis

DOE PAGES

Golovchak, R.; Lucas, P.; Oelgoetz, J.; ...

2015-01-13

We performed synchrotron X-ray diffraction and neutron scattering studies on As-Se glasses in two states: as-prepared (rejuvenated) and aged for similar to 27 years. The first sharp diffraction peak (FSDP) obtained from the structure factor data as a function of composition and temperature indicates that the cooperative processes that are responsible for structural relaxation do not affect FSDP. The results are correlated with the composition dependence of the complex heat capacity of the glasses and concentration of different structural fragments in the glass network. Furthermore, the comparison of structural information shows that density fluctuations, which were thought previously to havemore » a significant contribution to FSDP, have much smaller effect than the cation-cation correlations, presence of ordered structural fragments or cage molecules.« less

Stable isotope composition of cocoa beans of different geographical origin.

PubMed

Perini, Matteo; Bontempo, Luana; Ziller, Luca; Barbero, Alice; Caligiani, Augusta; Camin, Federica

2016-09-01

The isotopic profile (δ(13) C, δ(15) N, δ(18) O, δ(2) H, δ(34) S) was used to characterise a wide selection of cocoa beans from different renowned production areas (Africa, Asia, Central and South America). The factors most influencing the isotopic signatures of cocoa beans were climate and altitude for δ(13) C and the isotopic composition of precipitation water for δ(18) O and δ(2) H, whereas δ(15) N and δ(34) S were primarily affected by geology and fertilisation practises. Multi-isotopic analysis was shown to be sufficiently effective in determining the geographical origin of cocoa beans, and combining it with Canonical Discriminant Analysis led to more than 80% of samples being correctly reclassified. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Child-related cognitions and affective functioning of physically abusive and comparison parents.

PubMed

Haskett, Mary E; Smith Scott, Susan; Grant, Raven; Ward, Caryn Sabourin; Robinson, Canby

2003-06-01

The goal of this research was to utilize the cognitive behavioral model of abusive parenting to select and examine risk factors to illuminate the unique and combined influences of social cognitive and affective variables in predicting abuse group membership. Participants included physically abusive parents (n=56) and a closely-matched group of comparison parents (n=62). Social cognitive risk variables measured were (a) parent's expectations for children's abilities and maturity, (b) parental attributions of intentionality of child misbehavior, and (c) parents' perceptions of their children's adjustment. Affective risk variables included (a) psychopathology and (b) parenting stress. A series of logistic regression models were constructed to test the individual, combined, and interactive effects of risk variables on abuse group membership. The full set of five risk variables was predictive of abuse status; however, not all variables were predictive when considered individually and interactions did not contribute significantly to prediction. A risk composite score computed for each parent based on the five risk variables significantly predicted abuse status. Wide individual differences in risk across the five variables were apparent within the sample of abusive parents. Findings were generally consistent with a cognitive behavioral model of abuse, with cognitive variables being more salient in predicting abuse status than affective factors. Results point to the importance of considering diversity in characteristics of abusive parents.