Predicting the chemical composition of the body and the carcass of hair sheep using body parts and carcass measurements

Determination of the chemical composition in the body and carcass of ruminants is important for both nutritional requirement studies and the meat industry. This study aimed to develop equations to predict the body and carcass chemical composition of hair sheep using the chemical composition of body parts, carcass measurements and shrunk BW as predictors. A database containing 107 individual records for castrated male hair sheep ranging from 24 to 43 kg BW was gathered from two body composition studies. The empty body, carcass and body parts were analyzed for water, ash, fat and protein contents (%). The body parts used to estimate body and carcass composition were fore leg, hind leg and 9–11th rib section. The carcass measurements used were leg length, thoracic circumference, hind circumference, hind width, thoracic width, thoracic depth and chest width. Each model performance was evaluated using a leave-one-out cross-validation. Multiple regression analysis considering the study as a random effect revealed that body parts in association with carcass measurements were significant for predicting the chemical composition in the body of castrate male sheep. However, the use of the chemical composition of hind leg produced the best models for predicting the ash and fat contents in the empty body, whereas the water and protein contents in the empty body were better predicted when using the chemical compositions of 9–11th rib section and fore leg, respectively. Multiple regression analysis also revealed that most body parts were suitable for predicting the carcass composition, except for 9–11th rib section whose chemical composition did not produce significant prediction equations for ash and protein carcass contents. The use of the chemical composition of hind leg in association with carcass measurements produced the best models for predicting the water and fat contents in the carcass, while the ash and protein contents in the carcass were better predicted when using the chemical composition of fore leg. In conclusion, precision, accuracy and goodness-of-fit of the equations drove the selection of the chemical composition of hind leg and carcass measurements in a multivariate approach, as the most suitable predictors of the chemical composition of the body and carcass of hair sheep. However, the chemical composition of fore leg may be used as well. The developed equations could improve the accuracy of the empty body and carcass composition estimations in sheep, optimizing the estimation of nutrient requirements, as well as the carcass quality evaluation for this species.     

Heavy metal accumulation of Danube river aquatic plants — indication of chemical contamination

In this paper, the ecological status of a section of the Danube River flowing through Serbia from Bezdan to Djerdap was evalutated. Using the chemical composition of water, sediment samples from the littoral zone and dominant aquatic macrophytes, the level of chemical pollution was ascertained. Chemical analyses of the water and sediment indicated that the tributaries flowing into the Danube significantly influenced the chemical load of the water and as a direct consequence, the sediment. The concentration of heavy metals including Cu, Mn and Cd found in plants of the Potamogeton genus, further indicated significant chemical pollution, establishing a clear link between the chemical composition of plant tissues and the chemical composition of water and sediment. This paper therefore describes how the chemical composition of aquatic plants can be used as a reliable indicator for heavy metal pollution of aquatic ecosystems.     

梁河脂松节油、脂松香的物理和化学特征

研究梁河脂松节油的相对密度、折光率、初馏点、馏程体积、旋光度和化学组成以及脂松香的软化点、酸值、不皂化物含量、乙醇不溶物、灰分、旋光度和化学组成等物理和化学特征。结果表明:梁河的脂松节油在化学组成上因含有大量3-蒈烯导致其蒎烯含量低于GB/T 12901-2006,其物理指标中的折光率偏高。梁河的脂松香因化学组成中含有大量中性物,致其物理指标中酸值偏低,不皂化物含量偏高,超出GB/T 8145-2003。鉴于3-蒈烯这一特殊资源,有必要制定高3-蒈烯脂松节油标准。     

HPLC/HR-MS-Based Metabolite Profiling and Chemometrics: A Powerful Approach to Identify Bioactive Compounds from Abarema cochliacarpos

Despite its importance as a medicinal plant, there is a lack of studies that assessed the chemical composition of A. cochliacarpos extracts. Herein, we used a metabolite profiling approach and chemometrics as a powerful strategy to correlate the chemical composition with the antioxidant activity of A. cochliacarpos extracts. Extracts obtained with ethyl acetate showed greater antioxidant activity and higher total phenolic content than extracts obtained with hexane. The chemical composition was assessed by HPLC/HR-MS and it encompassed fatty alcohols, terpenoids, phenolic derivatives, lipids, carotenoid-like compounds, alkaloids, flavonoids, polyketides, and glycerophospholipids. Chemometrics successfully differentiated not only the chemical composition of extracts in response to the nature of the extraction solvent and the botanical part used during extraction but also it allowed us to associate the chemical composition with the antioxidant activity of the extracts, which might be particularly helpful for drug discovery and development programs.     

CO_2和温度升高及干旱对小麦叶片化学成分的影响

研究了 CO2 浓度升高、高温和干旱对干旱区小麦叶片化学成分的影响 ,结果表明 :CO2 浓度升高时各化学成分之间的差异只有在 40 %田间持水量时才表现显著 ,说明未来 CO2 浓度升高对干旱区小麦化学成分的影响可能大于在非干旱区的影响 ;CO2 浓度升高可减小因为土壤水分不同而造成的小麦化学成分之间的差异 ;高温对小麦化学成分的主要影响是引起 N含量的显著降低 ;CO2 浓度升高、高温和干旱三因子对干旱区小麦化学成分的复合影响是 N含量下降和 C/ N的显著上升 ,这可能对未来农田生态系统的分解速率产生影响     

麻竹材化学成分的变异

麻竹(ＤｅｎｄｒｏｃａｌａｍｕｓｌａｔｉｆｌｏｒｕｓＭｕｎｒｏ)是我国南方著名笋竹两用竹种,竹秆粗大通直,大量用于制浆造纸,是我国纸浆材培育的主要竹种之一。化学成分是研究竹材材性的基础和竹材利用的依据。有关麻竹材化学成分的研究未见报道。本文应用正交试验方?..     

猴头杜鹃木纤维形态特征和化学成分研究

通过对猴头杜鹃木材纤维形态和化学成分的测定、分析,揭示了猴头杜鹃木纤维形态和化学成分的特征及纤维形态随轮龄的变化规律。     

Evenness of soil organic carbon chemical components changes with tree species richness,composition and functional diversity across forests in China

Higher tree species richness generally increases the storage of soil organic carbon (SOC). However, less attention is paid to the influence of varied tree species composition on SOC storage. Recently, the perspectives for the stronger persistence of SOC caused by the higher molecular diversity of organic compounds were proposed. Therefore, the influences of tree species richness and composition on the molecular diversity of SOC need to be explored. In this study, an index of the evenness of diverse SOC chemical components was proposed to represent the potential resistance of SOC to decomposition under disturbances. Six natural forest types were selected encompassing a diversity gradient, ranging from cold temperate to tropical forests. We examined the correlations of tree species richness, composition, and functional diversity, with the evenness of SOC chemical components at a molecular level by ¹³C nuclear magnetic resonance. Across the range, tree species richness correlated to the evenness of SOC chemical components through tree species composition. The negative correlation of evenness of SOC chemical components with tree species composition, and the positive correlation of evenness of SOC chemical components with tree functional diversity were found. These indicate the larger difference in tree species composition and the lower community functional diversity resulted in the higher heterogeneity of SOC chemical components among the communities. The positive correlation of the evenness of SOC chemical components with the important value of indicator tree species, further revealed the specific tree species contributing to the higher evenness of SOC chemical components in each forest type. Soil fungal and bacterial α-diversity had effect on the evenness of SOC chemical components. These findings suggest that the indicator tree species conservation might be preferrable to simply increasing tree species richness, for enhancing the potential resistance of SOC to decomposition.     

Chemical composition distribution of bacterial copolyesters.

Poly(3-hydroxybutyrate) [P(3HB)] and its copolymers with hydroxyalkanoates are naturally occurring thermoplastic materials produced by bacteria. There are many potential uses for these copolyesters owing to their biodegradability and biocompatibility. The physical properties of the copolyesters vary depending on the chemical structure as well as the composition of the comonomers. Usually, we expect, copolymers to have a narrow chemical composition distribution (CCD). Several reports, however, have pointed out that some bacterial copolyesters have broad and/or multimodal CCD. Fractionation based on the chemical composition has also been reported for several bacterial copolyester samples. In this review, the literature concerning CCD and fractionation based on chemical composition is summarized. The width of CCD is approximated based on the data of diad sequence distribution. Generality of the complex CCD in bacterial copolyesters is also discussed.     

我国雪莲植物的种类、生境分布及化学成分的研究进展

本文对雪莲花的原植物种类、生境分布、生长习性做了分析整理,并对新疆雪莲、水母雪莲、雪兔子等六种雪莲植物化学成分研究进展进行了综述。从比较已有的实验结果中发现不同种雪莲在其特定生境下的化学成分既有属的同一性又存在种的特征性差异。这不仅为植物化学分类提供了证据,也为细胞大量培养选用品质优秀的原植物材料提供了资料     

我国雪莲植物的种类 生境分布及化学成分的研究进展

本文对雪莲花的原植物种类、生境分布、生长习性做了分析整理,并对新疆雪莲、水母雪莲、雪兔子等六种雪莲植物化学成分研究进展进行了综述。从比较已有的实验结果中发现不同种雪莲在其特定生境下的化学成分既有属的同一性又存在种的特征性差异。这不仅为植物化学分类提供了证据,也为细胞大量培养选用品质优秀的原植物材料提供了资料。     

Analysis of consequences of contribution from major sources of chemical matter in water of novosibirsk reservoir

The contribution of chemical matter from major sources to the composition of water in the Novosibirsk reservoir is assessed. It is confirmed that the chemical composition of water in the Novosibirsk reservoir is essentially formed due to the inflow of chemicals from the Ob’ river.     

紫菀属植物化学成分及药理作用研究进展

紫菀属(Aster L.)植物为多年生草本、亚灌木或灌木,该属植物中紫菀(Aster tataricus)为常用中药,具有润肺下气、止咳祛痰之功效,主治气逆咳嗽、痰吐不利、肺虚久咳、痰中带血等症,是临床常用的润肺祛痰止咳药。该属所含化学成分较丰富,已对该属中16种植物做过化学成分研究,分离出的化合物124个,其类型有各种萜类及其苷、肽类、黄酮类、蒽醌类、甾醇类、香豆素、有机酸类及挥发油等。对国内外有关该属植物的化学成分、药理作用和临床应用的最新研究进行了综述,为该药用植物资源的进一步研究和开发利用提供依据。     

Cellulase activity on decomposing leaf litter in microcosms

In this paper, we describe cellulase and cellobiose dehydrogenase (CBDH) dynamics in relation to incubation time, mass loss and chemical composition of decomposing deciduous leaf litter. Cellulose disappearance from litter coincided with periods of maximum cellulase activity. CBDH activity peaked later in decomposition after cellulase activity had declined. Enzyme activity patterns differed among litter types when expressed on the basis of decomposition time or cumulative mass loss. The patterns converged when expressed on the basis of chemical composition as indexed by the fraction of cellulose in the lignocellulose complex. We present a three-stage model of decomposition based on temporal changes in cellulase activities and coincident changes in litter chemical composition.     

Unravelling the mechanisms for plant survival on gypsum soils: an analysis of the chemical composition of gypsum plants from Turkey

Depending on their specificity to gypsum, plants can be classified as gypsophiles (gypsum exclusive) and gypsovags (non‐exclusive). The former may further be segregated into wide and narrow gypsophiles, depending on the breadth of their distribution area. Narrow gypsum endemics have a putative similar chemical composition to plants non‐exclusive to gypsum (i.e. gypsovags), which may indicate their similar ecological strategy as stress‐tolerant plant refugees on gypsum. However, this hypothesis awaits testing in different regions of the world. We compared the chemical composition of four narrow gypsum endemics, one widely distributed gypsophile and six gypsovags from Turkey. Further, we explored the plasticity in chemical composition of Turkish gypsovags growing on high‐ and low‐gypsum content soils. Differences were explored with multivariate analyses (RDA) and mixed models (REML). Narrow gypsum endemics segregated from gypsovags in their chemical composition according to RDAs (mainly due to higher K and ash content in the former). Nevertheless, differences were small and disappeared when different nutrients were analysed individually. All the gypsovags studied accumulated more S and ash when growing on high‐gypsum than on low‐gypsum soils. Similar to narrow gypsum endemics from other regions of the world, most local gypsum endemics from Turkey show a similar chemical composition to gypsovags. This may indicate a shared ecological strategy as stress‐tolerant plants not specifically adapted to gypsum. Nevertheless, the narrow gypsum endemic Gypsophila parva showed a chemical composition typical of gypsum specialists, indicating that various strategies are feasible within narrowly distributed gypsophiles.     

Fast classification and compositional analysis of cornstover fractions using Fourier transform near-infrared techniques

The objectives of this research were to determine the variation of chemical composition across botanical fractions of cornstover, and to probe the potential of Fourier transform near-infrared (FT-NIR) techniques in qualitatively classifying separated cornstover fractions and in quantitatively analyzing chemical compositions of cornstover by developing calibration models to predict chemical compositions of cornstover based on FT-NIR spectra. Large variations of cornstover chemical composition for wide calibration ranges, which is required by a reliable calibration model, were achieved by manually separating the cornstover samples into six botanical fractions, and their chemical compositions were determined by conventional wet chemical analyses, which proved that chemical composition varies significantly among different botanical fractions of cornstover. Different botanic fractions, having total saccharide content in descending order, are husk, sheath, pith, rind, leaf, and node. Based on FT-NIR spectra acquired on the biomass, classification by Soft Independent Modeling of Class Analogy (SIMCA) was employed to conduct qualitative classification of cornstover fractions, and partial least square (PLS) regression was used for quantitative chemical composition analysis. SIMCA was successfully demonstrated in classifying botanical fractions of cornstover. The developed PLS model yielded root mean square error of prediction (RMSEP %w/w) of 0.92, 1.03, 0.17, 0.27, 0.21, 1.12, and 0.57 for glucan, xylan, galactan, arabinan, mannan, lignin, and ash, respectively. The results showed the potential of FT-NIR techniques in combination with multivariate analysis to be utilized by biomass feedstock suppliers, bioethanol manufacturers, and bio-power producers in order to better manage bioenergy feedstocks and enhance bioconversion.     

Comparative chemical and molecular variability of Cananga odorata (Lam.) Hook.f. & Thomson forma genuina (ylang-ylang) in the Western Indian Ocean Islands: implication for valorization

Cananga odorata (Lam.) Hook.f. & Thomson forma genuina (Annonaceae) is a tropical tree, grown for the production of ylang-ylang essential oil, which is extracted from its fresh and mature flowers. Despite its economic and social importance, very little information is available on its variability and the possible factors causing it. Therefore, the relationship between the genetic structure, revealed by amplified fragment length polymorphism (AFLP), and the essential oil chemical composition, determined by GC/MS analysis, of ylang-ylang grown in semi-managed systems in three Indian Ocean islands (Grande Comore, Mayotte, and Madagascar) was investigated. Our results revealed a low genetic variation within plantations and contrasted situations between islands. Variations of the chemical composition could be observed within plantations and between islands. The genetic differentiation pattern did not match the observed pattern of chemical variability. Hence, the chemical variation could not be attributed to a genetic control. As Grande Comore, Madagascar, and Mayotte present different environmental and agronomic conditions, it can be concluded that the influence of these conditions on the ylang-ylang essential oil composition is consistent with the patterns observed. Finally, several strategies were proposed to valorize the chemical composition variations.     

Environmental impact of a large-scale chemical elimination of <Emphasis Type="Italic">Reynoutria</Emphasis> spp. on the alluvium of the Morávka river – examination of vegetation changes in floodplain forests

An invasion of non-native plant species represents the most serious environmental problem threatening the biodiversity and changing the nature of the landscape. A chemical elimination is one of the methods used to fight neophytes. It was carried out in the study area of the Morávka River flowing beneath the Beskydy Mountains between 2007 and 2010. The elimination of Reynoutria spp. was implemented as a part of the ‘Preservation of alluvial forest habitats in the Morávka River basin’ project. The population of the invasive neophyte Reynoutria spp. was eliminated by using a combination of mechanical and chemical treatment. Roundup Biaktiv herbicide was used for the chemical elimination. We investigated the consequences of the areal chemical elimination of Reynoutria spp. on the herbaceous undergrowth of the forest of the alluvium of the Morávka River. A multivariate analysis was employed to examine responses of the spring herbaceous plant species and native and non-native summer plant species composition to the chemical treatment. The hypothesis that consequences of the chemical elimination are not reflected in the spring plant species composition, whereas the applications of the herbicide and their frequency is one of crucial factors for the variability of the summer plant species composition was confirmed. The chemical elimination affected plant species composition of the non-native plant species more significantly than the plant species composition of the native plant species. A higher frequency of herbicide application caused increased diversity of both native and non-native plant species, although more noticeably in the case of the latter ones.     

Essential Oils from Piper caldense C. DC. and Piper xylosteoides (Kunth) Steud.: Seasonal Variation of the Chemical Composition and Antimicrobial Activity

The essential oils (EOs) chemical composition can be affected by several environmental factors, impacting their desired biological activities. In this sense, this work aimed to evaluate the seasonal variation of the chemical composition and antimicrobial activity of Piper caldense and Piper xylosteoides leaves EOs. Their chemical composition was determined by GC/MS and GC-FID analyses, resulting in the identification of eighty compounds. P. caldense EOs were mainly consisted of sesquiterpene hydrocarbons, whereas in P. xylosteoides EOs, monoterpene hydrocarbons were predominant. EOs from both species strongly inhibited B. subtilis (MIC=0.25 mg mL⁻¹), while only P. caldense EOs showed strong activity against S. aureus (MIC=0.50 mg mL⁻¹). P. caldense spring EO showed the broadest spectrum of antimicrobial action amongst all samples. For each species, PCA seasonally differentiated EOs chemical composition. In addition, as expected, PCA of all samples showed a distinction between the two species. This study has successfully demonstrated the importance of evaluating the seasonal variation of EOs chemical composition and antimicrobial activity in obtaining a product with the desired properties.     

Leaf waxes in Coincya Rouy (Brassicaceae)

A total of 55 populations belonging to the genus Coincya Rouy (Brassicaceae) from the Iberian Peninsula were examined for their leaf wax composition. The total wax content and the relative proportions of the five main lipid fractions, hydrocarbons, esters, ketones, free alcohols and free sterols were determined. It was observed that there was a positive correlation between chemical composition and environmental adaptation, and also with certain morphological characterS. Changes relate to low temperatures or to high relative humidity, and there is a positive correlation between chemical composition and leaf glaucosity.