scispace - formally typeset
Search or ask a question

Showing papers by "University of Hohenheim published in 2005"


Journal ArticleDOI
TL;DR: The concept of substituting bio-diesel produced from plantations on eroded soils for conventional diesel fuel has gained wide-spread attention in India as discussed by the authors, where the Indian central Government as well as some state governments have expressed their support for bringing marginal lands, which cannot be used for food production, under cultivation for this purpose.
Abstract: The concept of substituting bio-diesel produced from plantations on eroded soils for conventional diesel fuel has gained wide-spread attention in India. In recent months, the Indian central Government as well as some state governments have expressed their support for bringing marginal lands, which cannot be used for food production, under cultivation for this purpose. Jatropha curcas is a well established plant in India. It produces oil-rich seeds, is known to thrive on eroded lands, and to require only limited amounts of water, nutrients and capital inputs. This plant offers the option both to cultivate wastelands and to produce vegetable oil suitable for conversion to bio-diesel. More versatile than hydrogen and new propulsion systems such as fuel cell technology, bio-diesel can be used in today's vehicle fleets worldwide and may also offer a viable path to sustainable transportation, i.e., lower greenhouse gas emissions and enhanced mobility, even in remote areas. Mitigation of global warming and the creation of new regional employment opportunities can be important cornerstones of any forward looking transportation system for emerging economies.

543 citations


Journal ArticleDOI
TL;DR: High-performance liquid chromatography-diode array detector (DAD)-tandem mass spectrometry (MS/MS) measurements of cactus pear juices permitted the differentiation of the clones based on variations in pigment patterns and betalain concentrations.
Abstract: Total phenolics, ascorbic acid, and betalain contents of differently colored cactus pear clones (nine Opuntia ficus-indica [L.] Mill. clones and one O. robusta Wendl. clone) were investigated and related to their respective antioxidant potential assessed by Trolox-equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays. TEAC and ORAC values were very highly correlated with each other and also with values for total phenolics, betalain contents, and ascorbic acid concentrations. Total phenolics had the greatest contribution to ORAC and TEAC values. High-performance liquid chromatography (HPLC)-diode array detector (DAD)-tandem mass spectrometry (MS/MS) measurements of cactus pear juices permitted the differentiation of the clones based on variations in pigment patterns and betalain concentrations. The red and yellow betalains were absent in lime green colored cactus fruits. The ratio and concentration of these pigments were responsible for the yellow, orange, red, and purple colors in the other clones. Progeny of purple and lime green colored parents were characterized by 12% and 88% of plants bearing lime green and purple fruit, respectively. This implies that the genes for betalain production were lacking in the lime green fruits but could be provided by a parent with a complete set of genes, that is, purple fruits. Besides known pigments typical of Cactaceae, two unexpected betalains were identified. Whereas gomphrenin I was found for the first time in tissues of cactus plants, methionine-betaxanthin has never been described before as a genuine betalain. In addition to their alleged health-promoting properties, various combinations of yellow betaxanthins and red-purple betacyanins may allow the development of new food products without using artificial colorants.

476 citations


Journal ArticleDOI
TL;DR: It is concluded that much research is needed to get an insight into the multitude of bioactivities reported in the traditional literature but also to take advantage of the respective constituents for food and pharmaceutical applications.
Abstract: Although traditionally used as a valuable health supporting nutrient, the vegetative parts of Opuntia spp. plants are scarcely used in modern nutrition and medicine. While all kinds of different Opuntia spp. have been studied, a systematic approach regarding the inter-relationships between the composition and the pre- and postharvest conditions is still missing. Therefore, the present review compiles and discusses literature on the chemical composition of cactus stems, the knowledge on uses in food, medicine, and cosmetics. It is concluded that much research is needed to get an insight into the multitude of bioactivities reported in the traditional literature but also to take advantage of the respective constituents for food and pharmaceutical applications.

436 citations


Journal ArticleDOI
TL;DR: In this article, the authors provide a two-dimensional conceptualization of customer orientation that distinguishes between attitudes and behaviors, and explore direct and indirect effects of customer-oriented attitudes on customer satisfaction.
Abstract: The goal of this article is to provide deeper insights into the construct of customer orientation at the individual level. The article has three main objectives: First, this study provides a two-dimensional conceptualization of customer orientation that distinguishes between attitudes and behaviors. Second, it explores direct and indirect effects of customer-oriented attitudes on customer satisfaction. Third, the authors propose and examine a positive moderating effect of empathy, reliability, and expertise on the link between customer-oriented attitude and customer-oriented behavior and a negative moderating effect of salespeople’s restriction in job autonomy. The analysis is based on dyadic data that involve judgments provided by salespeople and their customers across multiple manufacturing and services industries in a business-to-business context. Results support the authors’ two-dimensional conceptualization of customer orientation. The authors also find that customer-oriented attitudes have a direct effect on customer satisfaction. The four proposed moderating effects are also in evidence.

399 citations


Journal ArticleDOI
TL;DR: The results indicate that breeders averted the narrowing of the wheat germplasm base and subsequently increased the genetic diversity through the introgression of novel materials.
Abstract: It has been claimed that plant breeding reduces genetic diversity in elite germplasm which could seriously jeopardize the continued ability to improve crops. The main objective of this study was to examine the loss of genetic diversity in spring bread wheat during (1) its domestication, (2) the change from traditional landrace cultivars (LCs) to modern breeding varieties, and (3) 50 years of international breeding. We studied 253 CIMMYT or CIMMYT-related modern wheat cultivars, LCs, and Triticum tauschii accessions, the D-genome donor of wheat, with 90 simple sequence repeat (SSR) markers dispersed across the wheat genome. A loss of genetic diversity was observed from T. tauschii to the LCs, and from the LCs to the elite breeding germplasm. Wheat’s genetic diversity was narrowed from 1950 to 1989, but was enhanced from 1990 to 1997. Our results indicate that breeders averted the narrowing of the wheat germplasm base and subsequently increased the genetic diversity through the introgression of novel materials. The LCs and T. tauschii contain numerous unique alleles that were absent in modern spring bread wheat cultivars. Consequently, both the LCs and T. tauschii represent useful sources for broadening the genetic base of elite wheat breeding germplasm.

393 citations


Journal ArticleDOI
TL;DR: Meat as a protein rich and carbohydrate "low" product contributes to a low glycemic index which is assumed to be "beneficial" with respect to overweight, the development of diabetes and cancer (insulin resistance hypothesis).

371 citations


Journal ArticleDOI
TL;DR: The importance of wildlife reservoirs in perpetuating transmission and as a source of infection for domestic animals and humans is addressed and the transmission pattern of a recently described new species, Echinococcus shiquicus, from China is referred to.

338 citations


Journal ArticleDOI
TL;DR: There is growing evidence that betaine could have a positive impact both on animal performance and carcass quality, and direct interactions of betaine with metabolism-regulating factors have to be considered.
Abstract: The present review summarises the potential nutritional and physiological functions of betaine as a feed additive in relation to performance criteria in livestock production. Betaine, the trimethyl derivative of the amino acid glycine, is a metabolite of plant and animal tissues. In plants, betaine is particularly synthesised and accumulated as an osmoprotectant against salt and temperature stress. In animals, betaine is the product of choline oxidation or it originates from nutritional sources. Over the past decades, numerous studies have been carried out to investigate the potential effects of betaine supplementation on animal performance. Due to its chemical structure, betaine shows the characteristics of a dipolar zwitterion resulting in osmoprotective properties. Promoting effects on the intestinal tract against osmotic stress occurring during diarrhoea or coccidiosis have been reported following betaine supplementation in pigs and poultry. There is also some evidence that dietary betaine may improve the digestibility of specific nutrients. As a product of choline oxidation, betaine is involved in transmethylation reactions of the organism. Betaine as a methyl donor provides its labile methyl groups for the synthesis of several metabolically active substances such as creatine and carnitine. Supplementation with betaine may decrease the requirement for other methyl donors such as methionine and choline. There is also some evidence for enhanced methionine availability after dietary supplementation of betaine resulting in improved animal performance. Alterations in the distribution pattern of protein and fat in the body have been reported following betaine supplementation. A more efficient use of dietary protein may result from a methionine-sparing effect of betaine, but also direct interactions of betaine with metabolism-regulating factors have to be considered. Though the mode of action of betaine as a carcass modifier remains open, there is, however, growing evidence that betaine could have a positive impact both on animal performance and carcass quality.

334 citations


Journal ArticleDOI
TL;DR: The authors proposed several deductive imputation procedures to improve the education variable in the IAB employment subsample by using multiple education information available in the data because the employees' education is reported at least once a year.
Abstract: The education variable in the IAB employment subsample has two shortcomings: missing values and inconsistencies with the reporting rule We propose several deductive imputation procedures to improve the variable They mainly use the multiple education information available in the data because the employees' education is reported at least once a year We compare the improved data from the different procedures and the original data in typical applications in labor economics: educational composition of employment, wage inequality, and wage regression We find, that correcting the education variable: (i) shows the educational attainment of the male labor force to be higher than measured with the original data, (ii) gives different values for some measures of wage inequality, and (iii) does not change the estimates in wage regressions much

322 citations


Journal ArticleDOI
TL;DR: This study shows that AtTIP2;1 and AtTip2;3 can mediate the extracytosolic transport of methyl-NH2 and NH3 across the tonoplast membrane and may participate in vacuolar ammonium compartmentation.
Abstract: While membrane transporters mediating ammonium uptake across the plasma membrane have been well described at the molecular level, little is known about compartmentation and cellular export of ammonium. (The term ammonium is used to denote both NH3 and NH4+ and chemical symbols are used when specificity is required.) We therefore developed a yeast (Saccharomyces cerevisiae) complementation approach and isolated two Arabidopsis (Arabidopsis thaliana) genes that conferred tolerance to the toxic ammonium analog methylammonium in yeast. Both genes, AtTIP2;1 and AtTIP2;3, encode aquaporins of the tonoplast intrinsic protein subfamily and transported methylammonium or ammonium in yeast preferentially at high medium pH. AtTIP2;1 expression in Xenopus oocytes increased 14C-methylammonium accumulation with increasing pH. AtTIP2;1- and AtTIP2;3-mediated methylammonium detoxification in yeast depended on a functional vacuole, which was in agreement with the subcellular localization of green fluorescent protein-fusion proteins on the tonoplast in planta. Transcript levels of both AtTIPs were influenced by nitrogen supply but did not follow those of the nitrogen-derepressed ammonium transporter gene AtAMT1;1. Transgenic Arabidopsis plants overexpressing AtTIP2;1 did not show altered ammonium accumulation in roots after ammonium supply, although AtTIP2;1 mRNA levels in wild-type plants were up-regulated under these conditions. This study shows that AtTIP2;1 and AtTIP2;3 can mediate the extracytosolic transport of methyl-NH2 and NH3 across the tonoplast membrane and may thus participate in vacuolar ammonium compartmentation.

313 citations


Journal ArticleDOI
TL;DR: The profile of flavonol glycosides of the peels proved to be highly characteristic and may therefore serve as a tool for authenticity control of mango puree concentrate, which is often produced from unpeeled fruits and represents an important intermediate for the production of mango nectars.
Abstract: With respect to their browning potential and in consideration of a combined recovery of pectin and phenolic compounds, peels of 14 cultivars and the flesh of nine cultivars of mango (Mangifera indica L.) fruits were analyzed for their contents of flavonol O- and xanthone C-glycosides by high-performance liquid chromatography (HPLC)−diode array detection−electrospray ionization mass spectrometry (ESI-MS). While total amounts of up to 4860 mg/kg dry matter demonstrated the peels to be a rich source of phenolic compounds, only traces could be detected in the flesh. The profile of flavonol glycosides of the peels proved to be highly characteristic and may therefore serve as a tool for authenticity control of mango puree concentrate, which is often produced from unpeeled fruits and represents an important intermediate for the production of mango nectars. Two compounds were isolated by preparative HPLC, and their structures were elucidated on the basis of ESI-MS as well as NMR spectroscopy, establishing the two...

Journal ArticleDOI
TL;DR: In this paper, two different options for the combined recovery of pectin and phenolic compounds from mango peels, a byproduct of industrial mango processing, were developed, which can easily be integrated in an existing pectins and polyphenols extraction process.
Abstract: Two different options for the combined recovery of pectin and phenolic compounds from mango peels, a byproduct of industrial mango processing, were developed. After extraction of dried mango peels with diluted sulfuric acid, the phenolic compounds were adsorbed using a styrene–divinylbenzene copolymerisate resin, and pectin was obtained from the effluent by precipitation with ethanol. Phenolic compounds were recovered from the resin with methanol and the eluate was lyophilized (Process I). Alternatively, the pectin was precipitated by adding the crude extract to ethanol. After removal of the organic solvent, the phenolic compounds were obtained from the aqueous phase of the precipitation bath using the adsorbent resin as described before (Process II). While in total, 129.4 mg/g polyphenols were detected in the lyophilizate obtained from Process I, only 71.0 mg/g dm could be recoverd from Process II. The profiles of the polyphenols were almost identical, revealing that during pectin precipitation preferential adsorption of polyphenolic compounds to the pectin may be excluded. Besides the characterization of the pectins and the phenolic compounds, investigations into the influence of the drying temperature on the polyphenolic content of the peels were carried out, indicating a significant loss of flavonol glycosides depending on heat exposure. On the other hand, some xanthone glycosides were formed during the drying process. Furthermore, antioxidative capacities of the lyophilized eluates were investigated using the DPPH, TEAC and FRAP assays. The antioxidative capacity of the extracts exceeded that of mangiferin and quercetin 3-O-glucoside, respectively, thus demonstrating mango peels to be a suitable source of health-beneficial compounds. The lyophilizates obtained from Process I showed higher antioxidative capacities in all three assays. These findings indicate a correlation between the amount of phenolic compounds and the antioxidative capacity. Industrial relevance Byproducts of mango processing amount to 35–60% of the total fruit weight. Their complete exploitation for further product recovery is a promising measure from both an environmental and economic point of view. In our previous study mango peels were found to be a rich source of pectin, with a high degree of esterification and phenolic compounds, like flavonol O- and xanthone C-glycosides. Therefore, two alternative processes for the combined recovery of pectin and polyphenols, which can easily be integrated in an existing pectin production process, were developed in the present study.

Journal ArticleDOI
TL;DR: It is revealed that the essential role of polySia resides in the control and coordination of NCAM interactions during mouse brain development, and this first demonstration in vivo that a highly specific glycan structure is more important than the glycoconjugate as a whole provides a novel view on the relevance of protein glycosylation for the complex process of building the vertebrate brain.

Journal ArticleDOI
TL;DR: The variation of the ecological parameters acting on the microbial association such as the nature of cereal, temperature, size of inoculum, and length of propagation intervals leads in each case to a characteristic species association, thus explaining that altogether 46 LAB species and 13 yeast species have been identified as sourdough specific.
Abstract: Cereals are globally number one as food crops as well as substrates for fermentation Well known products are beer, sake, spirits, malt vinegar, and baked goods made from doughs leavened by yeasts or sourdough Fermentation processes are enabled by technological measures that act on the metabolically resting grains and direct ecological factors controlling the activity of lactic acid bacteria and yeasts Fermentable substrates originate from endogenous or added hydrolytic enzyme activities Examples of their management are malting, koji technology, addition of enzymes from external sources and sourdough, which stands on the origin of all fermentation When sourdough is continuously propagated under the conditions applied in bakery practice, a stable association of only few species of lactic acid bacteria (LAB) and yeasts achieve dominance and ensure a controlled process The variation of the ecological parameters acting on the microbial association such as the nature of cereal, temperature, size of inoculum, and length of propagation intervals leads in each case to a characteristic species association, thus explaining that altogether 46 LAB species and 13 yeast species have been identified as sourdough specific

Journal ArticleDOI
TL;DR: It was concluded that foliar-applied Si can effectively control infections by P. xanthii only via the physical barrier of Si deposited on leaf surfaces, and/or osmotic effect of the silicate applied, but cannot enhance systemic acquired resistance induced by inoculation.
Abstract: Two cucumber (Cucumis sativus) cultivars differing in their resistance to powdery mildew, Ningfeng No. 3 (susceptible) and Jinchun No. 4 (resistant), were used to study the effects of foliar- and root-applied silicon on resistance to infection by Podosphaera xanthii (syn. Sphaerotheca fuliginea) and the production of pathogenesis-related proteins (PRs). The results indicated that inoculation with P. xanthii significantly suppressed subsequent infection by powdery mildew compared with noninoculation, regardless of Si application. Root-applied Si significantly suppressed powdery mildew, the disease index being lower in Si-supplied than in Si-deprived plants, regardless of inoculation treatment. The resistant cultivar had a more constant lower disease index than the susceptible cultivar, irrespective of inoculation or Si treatment. Moreover, with root-applied Si, activities of PRs (for example peroxidase, polyphenoloxidase and chitinase) were significantly enhanced in inoculated lower leaves or noninoculated upper leaves in inoculated plants of both cultivars. Root-applied Si significantly decreased the activity of phenylalanine ammonia-lyase in inoculated leaves, but increased it in noninoculated upper leaves. However, Si treatment failed to change significantly the activity of PRs in plants without fungal attack. Compared to the control (no Si), foliar-applied Si had no effects either on the suppression of subsequent infection by P. xanthii or on the activity of PRs, irrespective of inoculation. Based on the findings in this study and previous reports, it was concluded that foliar-applied Si can effectively control infections by P. xanthii only via the physical barrier of Si deposited on leaf surfaces, and/or osmotic effect of the silicate applied, but cannot enhance systemic acquired resistance induced by inoculation, while continuously root-applied Si can enhance defence resistance in response to infection by P. xanthii in cucumber.

Journal ArticleDOI
TL;DR: In this paper, a soil fractionation study was carried out to investigate: (a) the distribution of a range of hydrolytic enzymes involved in C, N and P transformations, (b) the effect of the location on their respective kinetics, and (c) the impact of long-term N fertilizer management on enzyme distribution and kinetic parameters.
Abstract: The location of extracellular enzymes within the soil architecture and their association with the various soil components affects their catalytic potential. A soil fractionation study was carried out to investigate: (a) the distribution of a range of hydrolytic enzymes involved in C, N and P transformations, (b) the effect of the location on their respective kinetics, (c) the effect of long-term N fertilizer management on enzyme distribution and kinetic parameters. Soil (silty clay loam) from grassland which had received 0 or 200 kg N ha(-1) yr(-1) was fractionated, and four particle-size fractions (> 200, 200-63, 63-2 and 0. 1-2 mum) were obtained by a combination of wet-sieving and centrifugation, after low-energy ultrasonication. All fractions were assayed for four carbohydrases (beta-cellobiohydrolase, N-acetyl-beta-glucosammidase, beta-glucosidase and beta-xylosidase), acid phosphatase and leucine-aminopeptidase using a microplate fluorimetric assay based on MUB-substrates. Enzyme kinetics (V-max and K-m) were estimated in three particle-size fractions and the unfractionated soil. The results showed that not all particle-size fractions were equally enzymatically active and that the distribution of enzymes between fractions depended on the enzyme. Carbohydrases predominated in the coarser fractions while phosphatase and leucine-aminopeptidase were predominant in the clay-size fraction. The Michaelis constant (K.) varied among fractions, indicating that the association of the same enzyme with different particle-size fractions affected its substrate affinity. The same values of Km were found in the same fractions from the soil under two contrasting fertilizer management regimes, indicating that the Michaelis constant was unaffected by soil changes caused by N fertilizer management. (C) 2004 Elsevier Ltd. All rights reserved.

Journal ArticleDOI
TL;DR: It is suggested that neither ABA nor ethylene are directly involved in the effects of N form on leaf growth, and stimulation of leaf growth by NO(3)(-) was consistently associated with increased concentration of the physiologically active forms of cytokinins, zeatin andZeatin riboside, in the xylem exudate, indicating a major role for cytokinin as long-distance signals mediating the shoot response to NO( 3)(-) perception in roots.
Abstract: Leaf growth of many plant species shows rapid changes in response to alterations of the form and the level of N supply. In hydroponically-grown tomato (Lycopersicon esculentum L.), leaf growth was rapidly stimulated by NO(3)(-) application to NH(4)(+) precultured plants, while NH(4)(+) supply or complete N deprivation to NO(3)(-) precultured plants resulted in a rapid inhibition of leaf growth. Just 10 microM NO(3)(-) supply was sufficient to stimulate leaf growth to the same extent as 2 mM. Furthermore, continuous NO(3)(-) supply induced an oscillation of leaf growth rate with a 48 h interval. Since changes in NO(3)(-) levels in the xylem exudate and leaves did not correlate with NO(3)(-)-induced alterations of leaf growth rate, additional signals such as phytohormones may be involved. Levels of a known inhibitor of leaf growth, abscisic acid (ABA), did not consistently correspond to leaf growth rates in wild-type plants. Moreover, leaf growth of the ABA-deficient tomato mutant flacca was inhibited by NH(4)(+) without an increase in ABA concentration and was stimulated by NO(3)(-) despite its excessive ethylene production. These findings suggest that neither ABA nor ethylene are directly involved in the effects of N form on leaf growth. However, under all experimental conditions, stimulation of leaf growth by NO(3)(-) was consistently associated with increased concentration of the physiologically active forms of cytokinins, zeatin and zeatin riboside, in the xylem exudate. This indicates a major role for cytokinins as long-distance signals mediating the shoot response to NO(3)(-) perception in roots.

Journal ArticleDOI
TL;DR: In this paper, the authors examined the development of compulsive buying in a maturing consumer society such as Germany and argued that developments characterizing mature consumer societies create an atmosphere which supports the rise of compensatory and compulsive purchases.

Journal ArticleDOI
TL;DR: The investigations show that genetical and mathematical properties of dissimilarity measures are of crucial importance when choosing a genetic Dissimilarity coefficient for analyzing molecular marker data and facilitate the interpretation of findings from molecular marker studies on a theoretically sound basis.
Abstract: A proper choice of a dissimilarity measure is important in surveys investigating genetic relationships among germplasm with molecular marker data. The objective of our study was to examine 10 dissimilarity coefficients widely used in germplasm surveys, with special focus on applications in plant breeding and seed banks. In particular, we (i) investigated the genetical and mathematical properties of these coefficients, (ii) examined consequences of these properties for different areas of application in plant breeding and seed banks, and (iii) determined relationships between these 10 coefficients. The genetical and mathematical concepts of the coefficients were described in detail. A Procrustes analysis of a published data set consisting of seven CIMMYT maize populations demonstrated close affinity between Euclidean, Rogers', modified Rogers', and Cavalli-Sforza and Edwards' distance on one hand, and Nei's standard and Reynolds dissimilarity on the other hand. Our investigations show that genetical and mathematical properties of dissimilarity measures are of crucial importance when choosing a genetic dissimilarity coefficient for analyzing molecular marker data. The presented results assist experimenters to extract the maximum amount of information from genetic data and, thus, facilitate the interpretation of findings from molecular marker studies on a theoretically sound basis.

Journal ArticleDOI
TL;DR: In this article, three legumes (Calopogonium mucunoides, Centrosema brasilianum, Stylosanthes capitata) and three grasses (Brachiaria brizantha, Cyperus aggregatus, Eleusine indica) were tested for their ability to stimulate microbial degradation in soil contaminated with 5% (w/w) of a heavy crude oil.
Abstract: Phytoremediation is a promising technology for the clean-up of petroleum-contaminated soils, especially in the tropics where climatic conditions favour plant growth and microbial activity and where financial resources can be limited. The objective of this work was to identify tropical plant species from the eastern savannahs of Venezuela suitable for this technology. Three legumes (Calopogonium mucunoides, Centrosema brasilianum, Stylosanthes capitata) and three grasses (Brachiaria brizantha, Cyperus aggregatus, Eleusine indica) were tested for their ability to stimulate microbial degradation in soil contaminated with 5% (w/w) of a heavy crude oil. In greenhouse experiments, plant biomass production and oil dissipation (total oil and grease, and fraction composition) were analysed after 90 and 180 days incubation. Although previously tested on their tolerance to oil contamination, the legumes died within six to eight weeks. The grasses showed reduced biomass production under the influence of the contaminant. Relative growth rates were higher in contaminated soil indicating a delay in plant growth patterns and development. Soil planted with B. brizantha and C. aggregatus showed a significantly lower oil concentration than non-vegetated soil. Furthermore, a positive correlation between root biomass production and oil degradation was found. Concentration of saturated hydrocarbons was always lower in planted than in unplanted soil. B. brizantha also caused a considerable reduction of aromatics. Based on these results, B. brizantha is recommended for follow-up investigations which could further develop the application of phytoremediation of petroleum-contaminated soils in the tropics.

Journal ArticleDOI
TL;DR: There is an urgent need for a systematic evaluation of the most active structural components of the saponins, and their interaction with the microbial community, the host animal, and the diet.
Abstract: Saponins are steroid or triterpene glycoside compounds found in a variety of plants. Some saponin-containing plants, mainly legumes, have been used as animal feed, but others are toxic. Several studies on the effect of saponins on ruminant production have also been reported. Some in vitro and in vivo experiments that demonstrate the beneficial effects of saponin such as defaunation of the rumen and manipulation of the end products of fermentation are described. Defaunation is the selective removal of protozoa from the rumen microbial ecosystem by a cell membrane cholesterol-saponin interaction, which causes cell rupture. Because protozoa in the rumen cause protein turnover by predating on bacteria, defaunation increases the nitrogen utilization of the ruminant and may lead to an increase in growth, milk, or wool production. The growth-promoting effect was evident in the high roughage diet suggesting that the application of saponins or saponin-containing plant materials may be beneficial for the subsistence farmers in developing countries. Saponins are deglycosylated by rumen microbes. Some sapogenins have been detected in the digestive tract of ruminants; however, the direct action of these compounds on the host animal is still unclear. No information on the effects of saponin on ruminant reproduction is available. There is an urgent need for a systematic evaluation of the most active structural components of the saponins, and their interaction with the microbial community, the host animal, and the diet. Along with these studies, the direct effects of saponins or their microbial degradation products on the host must be examined in order to get the full understanding of the metabolism and beneficial effects of saponins on animals.

Journal ArticleDOI
TL;DR: The effects of processing on trans–cis-isomerization is reviewed, with particular attention to β-carotene, lycopene, lutein, and zeaxanthin as the most widespread and important carotenoids.
Abstract: Carotenoids are important plant pigments and, therefore, constitute also part of the human diet. They predominantly occur in their all-trans configuration, however, processing may lead to the formation of cis-isomers which possess different biological properties such as decreased provitamin A activity, and altered bioavailability and antioxidant capacity. The objective of this contribution is to review the effects of processing on trans–cis-isomerization, with particular attention to β-carotene, lycopene, lutein, and zeaxanthin as the most widespread and important carotenoids. Furthermore, aspects of carotenoid isomer analysis and bioavailability are also included in this treatise.

Journal ArticleDOI
TL;DR: The single most important collagen crosslink known to date in diabetes and aging is glucosepane, a lysyl-arginine crosslink that forms under nonoxidative conditions as discussed by the authors.
Abstract: The aging extracellular matrix is characterized by an age-related increase in insolubilization, yellowing, and stiffening, all of which can be mimicked by the Maillard reaction in vitro These phenomena are accelerated in metabolic diseases such as diabetes and end-stage renal disease, which have in common with physiological aging the accumulation of various glycation products and cross-links Eight years ago we concluded that the evidence favored oxidative cross-linking in experimental diabetes [Monnier, VM et al 1996 The mechanism of collagen cross-linking in diabetes: a puzzle nearing completion Diabetes 45(Suppl 3): 67-72] and proposed a major role for a putative non-UV active cross-link derived from glucose Below, we provide an update of the field that leads to the conclusion that, while oxidation might be important for Maillard reaction-mediated cross-linking via Strecker degradation and allysine formation, the single most important collagen cross-link known to date in diabetes and aging is glucosepane, a lysyl-arginine cross-link that forms under nonoxidative conditions

Journal ArticleDOI
TL;DR: In this paper, the root-derived CO 2 efflux from soil (frequently termed rhizosphere respiration) is partitioned into actual root respiration (RR, respiration by autotrophic and heterotrophic organisms) and rhizomicrobial respiration(RMR) by heterotrophs, which is crucial in determining the carbon (C) and energy balance of plants and soils.
Abstract: Partitioning the root-derived CO 2 efflux from soil (frequently termed rhizosphere respiration) into actual root respiration (RR, respiration by autotrophs) and rhizomicrobial respiration (RMR, respiration by heterotrophs) is crucial in determining the carbon (C) and energy balance of plants and soils. it is also essential in quantifying C sources for rhizosphere microorganisms and in estimation of the C contributing to turnover of soil organic matter (SOM), as well as in linking net ecosystem production (NEP) and net ecosystem exchange (NEE). Artificial-environment studies such as hydroponics or sterile soils yield unrealistic C-partitioning values and are unsuitable for predicting C flows under natural conditions. To date, several methods have been suggested to separate RR and RMR in nonsterile soils: 1) component integration, 2) substrate-induced respiration, 3) respiration by excised roots, 4) comparison of root-derived 14 CO 2 with rhizomicrobial 14 CO 2 after continuous labeling, 5) isotope dilution, 6) model-rhizodeposition technique, 7) modeling of 14 CO 2 efflux dynamics, 8) exudate elution, and 9) δ 13 C of CO 2 and microbial biomass. This review describes the basic principles and assumptions of these methods and compares the results obtained in the original papers and in studies designed to compare the methods. The component-integration method leads to strong disturbance and non-proportional increase of CO 2 efflux from different sources. Four of the methods (5 to 8) are based on the pulse labeling of shoots in a 14 CO 2 atmosphere and subsequent monitoring of 14 CO 2 efflux from the soil. The model-rhizodeposition technique and exudate-elution procedure strongly overestimate RR and underestimate RMR. Despite alternative assumptions, isotope dilution and modeling of 14 CO 2 -efflux dynamics yield similar results. In crops and grasses (wheat, ryegrass, barley, buckwheat, maize, meadow fescue, prairie grasses), RR amounts on average to 48±5% and RMR to 52±5% of root-derived CO 2 . The method based on the 13 C isotopic signature of CO 2 and microbial biomass is the most promising approach, especially when the plants are continuously labeled in 13 CO 2 or 14 CO 2 atmosphere. The difference methods, i.e., trenching, tree girdling, root-exclusion techniques, etc., are not suitable for separating the respiration by autotrophic and heterotrophic organisms because the difference methods neglect the importance of microbial respiration of rhizodeposits.

Journal ArticleDOI
TL;DR: Protocols for in vitro propagation of non-toxic variety of J. curcas through axillary bud proliferation and direct adventitious shoot bud regeneration from leaf segments have been established and crossing studies revealed that outcrosses with toxic J.Curcas do not affect the phorbol ester content of seeds borne on the non-Toxic variety.
Abstract: Protocols for in vitro propagation of non-toxic variety of J. curcas through axillary bud proliferation and direct adventitious shoot bud regeneration from leaf segments have been established. Shoot bud proliferation from axillaries was assessed on an initial basal Murashige and Skoog (MS) salt medium supplemented with different concentrations of benzyladenine (BA), kinetin and thidiazuron (TDZ) followed by subculture to medium with 4.4-8.9 μM BA. Regardless of the concentration of BA in the subculture medium, shoot multiplication rate was optimum (10–12.3) with primary culture on medium supplemented with 2.3–4.5 μM TDZ. Efficient adventitious shoot regeneration from leaf tissues was achieved with culture on medium with 8.9–44.4 μM BA + 4.9 μM indole-3-butyric acid (IBA) followed by transfer to medium supplemented with 8.9 μM BA + 2.5 μM IBA. Similarity index between toxic Indian variety and the non-toxic variety based on 435 RAPD markers was 96.3%. Crossing studies followed by phorbol ester quantitation revealed that outcrosses with toxic J. curcas do not affect the phorbol ester content of seeds borne on the non-toxic variety.

Journal ArticleDOI
TL;DR: In this paper, the effects of insect-resistant Bt cotton on pesticide use and agricultural productivity in Argentina were analyzed based on farm survey data, and it was shown that the technology reduces application rates of toxic chemicals by 50 per cent, while significantly increasing yields.
Abstract: This article analyzes effects of insect-resistant Bt cotton on pesticide use and agricultural productivity in Argentina. Based on farm survey data, it is shown that the technology reduces application rates of toxic chemicals by 50 per cent, while significantly increasing yields. Using a damage control framework, the effectiveness of Bt versus chemical pesticides is estimated, and technological impacts are predicted for different farm types. Gross benefits could be highest for smallholder farmers, who are not currently using the technology. The durability of the advantages is analyzed by using biological models to simulate resistance development in pest populations. Rapid resistance buildup and associated pest outbreaks appear to be unlikely if minimum non-Bt refuge areas are maintained. Thus, promoting a more widespread diffusion of Bt cotton could amplify the efficiency, equity, and environmental gains. Conclusive statements about the technology's sustainability, however, require longer-term monitoring of possible secondary effects and farmers' behavior in maintaining refuges.

Journal ArticleDOI
TL;DR: Selective genotyping and/or selective phenotyping approaches could be effective strategies for reducing the costs associated with conducting QTL analysis in large populations using the barley/barley stripe rust pathosystem to evaluate the effect of population size on the estimation of QTL parameters.
Abstract: The limited population sizes used in many quantitative trait locus (QTL) detection experiments can lead to underestimation of QTL number, overestimation of QTL effects, and failure to quantify QTL interactions. We used the barley/barley stripe rust pathosystem to evaluate the effect of population size on the estimation of QTL parameters. We generated a large (n=409) population of doubled haploid lines derived from the cross of two inbred lines, BCD47 and Baronesse. This population was evaluated for barley stripe rust severity in the Toluca Valley, Mexico, and in Washington State, USA, under field conditions. BCD47 was the principal donor of resistance QTL alleles, but the susceptible parent also contributed some resistance alleles. The major QTL, located on the long arm of chromosome 4H, close to the Mlo gene, accounted for up to 34% of the phenotypic variance. Subpopulations of different sizes were generated using three methods—resampling, selective genotyping, and selective phenotyping—to evaluate the effect of population size on the estimation of QTL parameters. In all cases, the number of QTL detected increased with population size. QTL with large effects were detected even in small populations, but QTL with small effects were detected only by increasing population size. Selective genotyping and/or selective phenotyping approaches could be effective strategies for reducing the costs associated with conducting QTL analysis in large populations. The method of choice will depend on the relative costs of genotyping versus phenotyping.

Journal ArticleDOI
TL;DR: In this paper, the relation between democracy and perceived subjective well-being, taking also into account the impact of income and culture, was examined. But no robust relationship between the extent of (direct) democracy and happiness can be observed.
Abstract: We look at the relation between democracy and perceived subjective well-being, taking also into account the impact of income and culture After briefly reviewing the empirical results for Switzerland, we re-estimate this relationship allowing for the relative income position of individuals and also using a new more recent data from the Swiss Household Panel No robust relationship between the extent of (direct) democracy and happiness can be observed In a second step, we conduct a cross-national analysis, covering 28 countries with data from the 1998 International Social Survey Programme (ISSP) There we observe a robust positive and significant relationship between democracy and happiness

Journal ArticleDOI
TL;DR: The results indicate that a high proportion of the observed LD is generated by forces, such as relatedness, population stratification, and genetic drift, which cause a high risk of detecting false positives in association mapping.
Abstract: Information about the extent and genomic distribution of linkage disequilibrium (LD) is of fundamental importance for association mapping. The main objectives of this study were to (1) investigate genetic diversity within germplasm groups of elite European maize (Zea mays L.) inbred lines, (2) examine the population structure of elite European maize germplasm, and (3) determine the extent and genomic distribution of LD between pairs of simple sequence repeat (SSR) markers. We examined genetic diversity and LD in a cross section of European and US elite breeding material comprising 147 inbred lines genotyped with 100 SSR markers. For gene diversity within each group, significant (P<0.05) differences existed among the groups. The LD was significant (P<0.05) for 49% of the SSR marker pairs in the 80 flint lines and for 56% of the SSR marker pairs in the 57 dent lines. The ratio of linked to unlinked loci in LD was 1.1 for both germplasm groups. The high incidence of LD suggests that the extent of LD between SSR markers should allow the detection of marker-phenotype associations in a genome scan. However, our results also indicate that a high proportion of the observed LD is generated by forces, such as relatedness, population stratification, and genetic drift, which cause a high risk of detecting false positives in association mapping.

Journal ArticleDOI
TL;DR: This paper marks the first report on HPLC-DAD/ESI-MSn investigations of phenolic compounds in dandelion and reveals that even more quercetin glycosides were found in dandalion than hitherto assumed.
Abstract: Phenolic acids and flavonoids were extracted from a dandelion (Taraxacum officinale WEB. ex WIGG.) root and herb juice and characterized by high-performance liquid chromatography/electrospray ionization mass spectrometry. Among the 43 compounds detected, 5 mono- and dicaffeoylquinic acids, 5 tartaric acid derivatives, 8 flavone and 8 flavonol glycosides were characterized based on their UV spectra and their fragmentation patterns in collision-induced dissociation experiments. The predominant compound was chicoric acid (dicaffeoyltartaric acid). Furthermore, several caffeoylquinic acid isomers were distinguished in dandelion extracts for the first time by their specific mass spectral data. The present study reveals that even more quercetin glycosides were found in dandelion than hitherto assumed. The occurrence of di- and triglycosylated flavonoids in particular has not yet been described. This paper marks the first report on HPLC-DAD/ESI-MSn investigations of phenolic compounds in dandelion.