Great Extent (great + extent)

Distribution by Scientific Domains

Selected Abstracts

Of Dodos and Dutchmen: reflections on the nature of history

History-making is a defining property of the human species; the ability to retain information in symbolic form over time (an ability which is granted principally by the presence of true natural language) is a unique attribute of the human animal. It has allowed human beings to enter in a qualitatively different relationship with the physical environment, and to operate in and alter that environment in highly complex, highly effective ways. To a great extent, the types of events that structure this way of life are absent from the rest of the natural world; in order to describe them accurately, it is necessary to attend to the special quality which defines them, a quality which we can characterise as their 'historical-ness'. Descriptions of human events cannot overlook the histories that organise and determine them, and to that extent they are not fruitfully apprehended with the tools of the exact sciences and instead require attention from the social sciences; but nevertheless, the phenomena of history are a part of the natural world, since they are part of the life of the organism. History itself arises in the non-historical crucible of biology. The paper examines a particular suite of events which have distinct historical and non-historical aspects - the extinction of the Dodo - in order to explore the epistemological difficulties which necessarily complicate any attempt to view human conduct as an integrated part of the natural world. [source]

Cytoplasmic fatty acid-binding protein facilitates fatty acid utilization by skeletal muscle

J. F. C. Glatz
Abstract The intracellular transport of long-chain fatty acids in muscle cells is facilitated to a great extent by heart-type cytoplasmic fatty acid-binding protein (H-FABP). By virtue of the marked affinity of this 14.5-kDa protein for fatty acids, H-FABP dramatically increases their concentration in the aqueous cytoplasm by non-covalent binding, thereby facilitating both the transition of fatty acids from membranes to the aqueous space and their diffusional transport from membranes (e.g. sarcolemma) to other cellular compartments (e.g. mitochondria). Striking features are the relative abundance of H-FABP in muscle, especially in oxidative muscle fibres, and the modulation of the muscular H-FABP content in concert with the modulation of other proteins and enzymes involved in fatty acid handling and utilization. Newer studies with mice carrying a homozygous or heterozygous deletion of the H-FABP gene show that, in comparison with wild-type mice, hindlimb muscles from heterozygous animals have a markedly lowered (,66%) H-FABP content but unaltered palmitate uptake rate, while in hindlimb muscles from homozygous animals (no H-FABP present) palmitate uptake was reduced by 45%. These findings indicate that H-FABP is present in relative excess and plays a substantial, but merely permissive role in fatty acid uptake by skeletal muscles. [source]

Vegetation of the river Yamuna floodplain in the Delhi stretch, with reference to hydrological characteristics

ECOHYDROLOGY, Issue 2 2009
Tanveera Tabasum
Abstract Vegetation in the Delhi stretch of the floodplain of the river Yamuna was examined in relation to hydrological characteristics. The floodplain was delineated into four zones based on hydrological interventions. Seventy-four plant species including forty-two aquatic/semi-aquatic were identified. The decrease in water discharge from Jhangola to downstream Okhla, led to reduction in species richness. Co-structures between hydrological characteristics and vegetational composition indicated that vegetation in the four identified zones was governed essentially by hydrological factors. Zones I and III exhibited near-perfect correspondence signifying that variation in vegetational composition in these zones could be explained, to a great extent, on the basis of variations in the hydrological conditions. Zone II and IV, with relatively weaker correspondence, indicated that there were gradients other than hydrological conditions, which caused variations in vegetational characteristics. The present study highlighted the importance of allocation of water for periodic inundation to maintain floodplain characteristics including aquatic/semi-aquatic vegetation cover as critical to the management of the river ecosystem. The current policy of water use focused entirely on human uses ignoring ecological requirements, and had clear adverse implications on the health of the river ecosystem. Copyright 2009 John Wiley & Sons, Ltd. [source]

Functional response and size-dependent foraging on aquatic and terrestrial prey by brown trout (Salmo trutta L.)

P. Gustafsson
Gustafsson P, Bergman E, Greenberg LA. Functional response and size-dependent foraging on aquatic and terrestrial prey by brown trout (Salmo trutta L.).Ecology of Freshwater Fish 2010: 19: 170,177. 2010 John Wiley & Sons A/S Abstract ,, Terrestrial invertebrate subsidies are believed to be important energy sources for drift-feeding salmonids. Despite this, size-specific use of and efficiency in procuring this resource have not been studied to any great extent. Therefore, we measured the functional responses of three size classes of wild brown trout Salmo trutta (0+, 1+ and ,2+) when fed either benthic- (Gammarus sp.) or surface-drifting prey (Musca domestica) in laboratory experiments. To test for size-specific prey preferences, both benthic and surface prey were presented simultaneously by presenting the fish with a constant density of benthic prey and a variable density of surface prey. The results showed that the functional response of 0+ trout differed significantly from the larger size classes, with 0+ fish having the lowest capture rates. Capture rates did not differ significantly between prey types. In experiments when both prey items were presented simultaneously, capture rate differed significantly between size classes, with larger trout having higher capture rates than smaller trout. However, capture rates within each size class did not change with prey density or prey composition. The two-prey experiments also showed that 1+ trout ate significantly more surface-drifting prey than 0+ trout. In contrast, there was no difference between 0+ and ,2+ trout. Analyses of the vertical position of the fish in the water column corroborated size-specific foraging results: larger trout remained in the upper part of the water column between attacks on surface prey more often than smaller trout, which tended to seek refuge at the bottom between attacks. These size-specific differences in foraging and vertical position suggest that larger trout may be able to use surface-drifting prey to a greater extent than smaller conspecifics. [source]


In this paper the causal chain connecting the economy and the vote in 2001 Galician regional elections is analyzed. Our findings demonstrate that economic voting is not just a matter of reactions to economic perceptions. It also depends to a great extent on two intermediate mechanisms: whether or not the incumbent is held responsible for economic outcomes and performance and voters' views of the relative economic management capabilities of opposition parties. [source]

Investigation of an onsite wastewater treatment system in sandy soil: Site characterization and fate of anionic and nonionic surfactants

Allen M. Nielsen
Abstract This study reports on the fate of linear alkylbenzene sulfonate (LAS), alcohol ethoxylate (AE), and alcohol ether sulfate (AES) surfactants in a home septic system near Jacksonville (FL, USA) that has been used since 1976. The drainfield at this site resides in fine sand (<6% silt and clay) with an unsaturated zone that ranges from 0 to 1.3 m. During the wettest times of the year, it is likely that effluent from the septic system passes directly into the groundwater without exposure to an unsaturated zone of soil. Groundwater was collected during two sampling events, representing seasonal high and low groundwater table levels, and analyzed for the surfactants LAS, AES, and AE. During the wet season, the unsaturated zone was approximately 0.01 m beneath the drainfield. During the dry season, the unsaturated zone was about 0.4 m below the drainfield. Alcohol ethoxylate was not detected in any groundwater samples during either sampling. Alcohol ether sulfate was not found in the dry season sampling, but traces of AES had migrated downgradient about 4.7 m horizontally and 1.8 m vertically in the wet season. Linear alkylbenzene sulfonate was detected in some dry season samples and had moved downgradient some 11.7 m horizontally and 3.7 m vertically in the wet season. These observations demonstrate that these surfactants were removed to a great extent; otherwise, they would have traveled more than 260 m downgradient, which is the calculated distance that a conservative tracer like bromide would have moved downgradient over the life of the system. The most likely removal mechanisms for these surfactants were biodegradation and sorption. Therefore, this study indicates that LAS, AE, and AES are readily removed from groundwater in soils below septic system drainfields even in situations with minimal unsaturated soil zones. [source]

Synthesis and Photochromism of Novel Chromene Derivatives Bearing a Monoazacrown Ether Moiety

Saleh A. Ahmed
Abstract Crowned chromenes , four novel naphthopyrans (chromenes) bearing monoaza-12-crown-4, -15-crown-5, -18-crown-6, and a noncyclic analogue at the 5-position , were synthesized, and their photochromism in acetonitrile was examined in the presence of alkali and alkaline-earth metal ions. Incorporation of crown ether units to chromene moieties facilitated to a great extent both the thermal isomerization and photoisomerization of the chromene moiety, reflecting the metal-ion-binding ability of the crown ether moiety. Comparison of the crowned chromenes with the corresponding crowned spirobenzopyrans reveals that photochromism of the crowned chromene reflects an interaction between the metal ion and the crown ether moiety that is stronger than that of the crowned spirobenzopyran, and shows only positive photochromism with significant red-shifts in the UV/Vis absorption spectra, in contrast to the crowned spirobenzopyrans reported previously. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

Test of Nyborg's General Trait Covariance (GTC) model for hormonally guided development by means of structural equation modeling

Martin Reuter
Nyborg's General Trait Covariance (GTC) model for hormonally guided development investigates the influence of gonadal hormones and fluid intelligence on body build, achievement, and socioeconomic variables. According to the model, testosterone should be negatively related to height, fat/muscle ratio, intelligence, income, and education. It is conceived that this influence should be determined to a great extent by mutual relationships between these variables. The model was tested by means of structural equation modeling (SEM) in a sample of 4375 males who had served in the United States Armed Forces. The results largely confirm Nyborg's androtype model but in addition reflect the relationships between the variables included in a quantitative causal manner. It could be shown that testosterone has a negative influence on crystallized intelligence and that this effect is mainly mediated by the negative influence of testosterone on education. An additional multiple group analysis testing for structural invariance across age groups revealed that the mediating role of education is more pronounced in old veterans. Copyright 2002 John Wiley & Sons, Ltd. [source]

Optimal Control of Rigid-Link Manipulators by Indirect Methods

Rainer Callies
Abstract The present paper is a survey and research paper on the treatment of optimal control problems of rigid-link manipulators by indirect methods. Maximum Principle based approaches provide an excellent tool to calculate optimal reference trajectories for multi-link manipulators with high accuracy. Their major drawback was the need to explicitly formulate the complicated system of adjoint differential equations and to apply the full apparatus of optimal control theory. This is necessary in order to convert the optimal control problem into a piecewise defined, nonlinear multi-point boundary value problem. An accurate and efficient access to first- and higher-order derivatives is crucial. The approach described in this paper allows it to generate all the derivative information recursively and simultaneously with the recursive formulation of the equations of motion. Nonlinear state and control constraints are treated without any simplifications by transforming them into sequences of systems of linear equations. By these means, the modeling of the complete optimal control problem and the accompanying boundary value problem is automated to a great extent. The fast numerical solution is by the advanced multiple shooting method JANUS. ( 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Metal-Free Click Polymerization: Synthesis and Photonic Properties of Poly(aroyltriazole)s

Anjun Qin
Abstract Regioselective 1,3-dipolar polycycloadditions of tetraphenylethene (TPE)-containing diazides 1,3 and bis(aroylacetylene) 4 are initiated by simple heating, affording poly(aroyltriazole)s (PATAs) PI,PIII with high molecular weights in high yields. The PATAs are completely soluble in common organic solvents and stable at temperatures up to 358,C. Thanks to their TPE units, the polymers show aggregation-induced emission and work as explosive sensors with high sensitivity. The PATAs are optically transparent in the whole visible spectral region. Their refractive indexes can be tuned to a great extent (,n,,,0.08) by simply changing their alkyl spacer lengths. The modified Abb numbers of the PATAs are very high (up to 273), indicative of very low optical dispersions in the telecommunication-important wavelength region. UV irradiation through a photomask quenches the light emissions of the polymers, enabling the generation of two-dimensional fluorescent images without development. The polymers can be readily photo-crosslinked, yielding three-dimensional patterns with high resolutions. [source]

Islam in Northern Mozambique: A Historical Overview

Liazzat Bonate
This article is a historical overview of two issues: first, that of the dynamics of Islamic religious transformations from pre-Portuguese era up until the 2000s among Muslims of the contemporary Cabo Delgado, Nampula, and to a certain extent, Niassa provinces. The article argues that historical and geographical proximity of these regions to East African coast, the Comoros and northern Madagascar meant that all these regions shared a common Islamic religious tradition. Accordingly, shifts with regard to religious discourses and practices went in parallel. This situation began changing in the last decade of the colonial era and has continued well into the 2000s, when the so-called Wahhabis, Sunni Muslims educated in the Islamic universities of the Arab world brought religious outlook that differed significantly from the historical local and regional conceptions of Islam. The second question addressed in this article is about relationships between northern Mozambican Muslims and the state. The article argues that after initial confrontations with Muslims in the sixteenth century and up until the last decade of the colonial era, the Portuguese rule pursued no concerted effort in interfering in the internal Muslim religious affairs. Besides, although they occupied and destroyed some of the Swahili settlements, in particular in southern and central Mozambique, other Swahili continued to thrive in northern Mozambique and maintained certain independence from the Portuguese up until the twentieth century. Islam there remained under the control of the ruling Shirazi clans with close political, economic, kinship and religious ties to the Swahili world. By establishing kinship and politico-economic ties with the ruling elites of the mainland in the nineteenth century, these families were also instrumental in expanding Islam into the hinterland. Only at the beginning of the twentieth century, the Portuguese rule took full control of the region as a result of military conquests of the ,effective occupation', and imposed new legal and administrative colonial system, called Indigenato, impacting Muslims of northern Mozambique to a great extent. After the independence in 1975, and especially since 1977, the post-independence Frelimo government adopted militant atheism and socialist Marxism, which was short-lived and was abolished in 1983 owing to popular resistance and especially, because of government's perception that its religious policies were fuelling the opposition groups to take arms and join the civil war. The 1980s and 1990s were marked by an acute rivalry and conflicts between the two emerging national umbrella Islamic organizations, the Islamic Council and the Islamic Congress, each representing largely pro-Sufi and anti-Sufi positions. In the 2000s, these organizations became overshadowed by new and more dynamic organizations, such as Ahl Al-Sunna. [source]

Sustainable consumption and the financial sector: analysing the markets for responsible investment in Hong Kong and Japan

Jacob ParkArticle first published online: 6 APR 200
Abstract The origins of the modern socially responsible investment (SRI) movement can be traced to the turbulent period in the 1960s when powerful social undercurrents including environmentalism and anti-war activism fuelled a rise, in a radical change, in the way society viewed faith, values and commerce. Today, nearly 1 out of every US$9 under professional management in the US is currently invested using social investment strategies while the European green and ethical investment market is estimated to be ,1 trillion or as much as 10,15% of the total funds under management. While some preliminary figures and analyses exist for countries outside these two regions, SRI has been, to date, largely explored within the context of North America and Europe. This is unfortunate as the sustainability of SRI as a consumer market is going to depend, to a great extent, to what happens outside of North America and Europe, and most notably in the rapidly developing Asian economies. In this article, I will explore the development of SRI as a mainstream financial consumer instrument in industrialized (Japan) and emerging (Hong Kong/China) economies of the Asia Pacific region. To fully analyse the SRI market development in Hong Kong and Japan, I will examine the following three issues and questions: first, how does the sustainable consumption framework offer a useful lens from which to explore SRI, and why is the Asia Pacific market and policy context so important for the broader issue of sustainable consumption? Second, what precisely is SRI and how did it develop into an important global financial investment vehicle? Third, how did the SRI market develop in the case of Hong Kong and Japan? I will then conclude the article with some analysis on the important lessons SRI market development in Hong Kong and Japan hold for market sustainability of the financial sector and sustainable consumption. [source]

Effect of hydrogen peroxide treatment on the quality of raw cream

The effect of hydrogen peroxide on the attributes of raw cream was studied. The samples with 500 mg/kg and 1500 mg/kg hydrogen peroxide (H2O2) were compared with an untreated control sample. The results indicated that the addition of hydrogen peroxide prevented, to a great extent, the development of lipolysis, proteolysis and acidity, as well as the growth of psychrotrophic microorganisms. However, the treatment had a negative effect on the oxidative stability of the cream. [source]

Application of a genetic algorithm in an artificial neural network to calculate the resonant frequency of a tunable single-shorting-post rectangular-patch antenna

Shyam S. Pattnaik
Abstract In this article, an efficient application of a genetic algorithm (GA) in an artificial neural network (ANN) to calculate the resonant frequency of a coaxially-fed tunable rectangular microstrip-patch antenna is presented. For a normal feed-forward back-propagation algorithm, with a compromise between time and accuracy, it is difficult to train the network to achieve an acceptable error tolerance. The selection of suitable parameters of ANNs in a feed-forward network leads to a high number of man-hours necessary to train a network efficiently. However, in the present method, the GA is used to reduce the man-hours while training a neural network using the feed forward-back-propagation algorithm. It is seen that the training time has also been reduced to a great extent while giving high accuracy. The results are in very good agreement with the experimental results. 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005. [source]

A model for evaluating the effectiveness of middle managers' training courses: evidence from a major banking organization in Greece

Ekaterini Galanou
Contemporary management thinking embraces the organizational training theory that sustainable success rests, to a great extent, upon a systematic evaluation of training interventions. However, the evidence indicates that few organizations take adequate steps to assess and analyse the quality and outcomes of their training. The authors seek to develop the existing literature on training evaluation by proposing a new model, specific to management training, which might encourage more and better evaluation by practitioners. Their thesis is that training evaluation is best if it can be based on criteria derived from the objectives of the training and they draw on the management effectiveness literature to inform their proposed model. The study seeks to examine the effect of six evaluation levels , reactions, learning, job behaviour, job performance, organizational team performance and some wider, societal effects , in measuring training interventions with regard to the alterations to learning, transfer and organizational impact. The model was tested with data obtained from 190 middle managers employed by a large banking organization in Greece and the results suggest that there is considerable consistency in the evaluation framework specified. The paper discusses these results and draws conclusions about their practical implications. The study's limitations are considered and some future research needs identified. [source]

Telling the Truth, Naming the Power and Confessing our Faith in the Market: The Missiological Implications of the Accra Confession

Roderick R. Hewitt
This article argues that the neoliberal economic order that undergirds the contemporary phase of globalization is, to a great extent, linked to the demise of Christendom in Western society and the emergence of a post-Christendom culture and this carries major missiological implications for the church. Fidelity to the Christian faith requires affirming God's sovereignty over all of God's creation and this necessitates resisting the deceptive economic idolatry that is at work in our world. The methodology of engagement involves taking sides on issues and choices that are unclear and complex. Using Caribbean hermeneutics in a re-reading of Rev. 17 and 18, I suggest that the Book of Revelation serves as a potent signpost to address the contemporary Babylonian system that is controlling the world economic order. The Accra Confession and the Agape Call to Love and Action do not leave room for the church's ministry and mission to be neutral. Although the forces of opposition are strong, I argue that the church that remains faithful in doing Christ's mission cannot be defeated. [source]

Rheological properties and processability of chemically modified poly(ethylene terephthalate- co -ethylene isophthalate)

Masayuki Yamaguchi
Abstract Rheological properties and extrusion processability have been evaluated for poly(ethylene terephthalate- co -ethylene isophthalate) (P(ET-EI)) modified by a styrene-acrylate-based copolymer with glycidyl functionality in an extruder. Adding a small amount of the modifier enhances melt elasticity to a great extent. Consequently, modified P(ET-EI) exhibits excellent processability without sagging, that is, downward deformation of extrudates by gravitational force. Considering that molecular weight and its distribution hardly change, which is confirmed by GPC measurements, generation of long-chain branches is responsible for the rheological properties and thus the processability. 2007 Wiley Periodicals, Inc. Adv Polym Techn 25:236,241, 2006; Published online in Wiley InterScience ( DOI 10.1002/adv.20078 [source]

Rheological properties of LDPE processed by conventional processing machines

Masayuki Yamaguchi
Abstract The impact of applied processing history and the postprocessing annealing on the rheological properties of low-density polyethylene (LDPE) have been studied employing various kinds of conventional processing machines. Processing by a corotating twin-screw extruder (Co-TSE) and an internal batch mixer depressed the drawdown force, one of the elastic properties of a melt, to a great extent, even though molecular weight and the polydispersity did not change. On the other hand, the sample processed by a two-roll mill exhibited the drawdown force as high as the original pellets, which is owing to the intermittent stress history instead of the relentless one in the Co-TSE and the internal batch mixer. Furthermore, the effect of screw configuration in the Co-TSE has also been investigated. It was found that the processing by conveying screws depressed the drawdown force and melt fracture more than that by kneading blocks as long as the torque and the residence time are the same. The large, abrupt, and frequent change in flow direction in the Co-TSE with kneading blocks prohibits the molecular orientation, which leads to disentanglement associated with long-chain branches. 2003 Wiley Periodicals, Inc. Adv Polym Techn 22: 179,187, 2003; Published online in Wiley InterScience ( DOI 10.1002/adv.10047 [source]

Assessing competency in nursing: a comparison of nurses prepared through degree and diploma programmes

Michael Clinton MSc
Aims and objectives., The present study aimed to investigate the competencies of qualifiers from three-year degree and three-year diploma courses in England at one, two and three years after qualification. Background., The provision of three-year preregistration nursing degrees in the UK has increased in recent years and in many colleges degrees are offered alongside the existing three-year diploma courses. Yet little is known about the relationship between these different education programmes and the competence of qualifiers. Methods., A cross-sectional survey design was employed to make comparisons of both self-reported and line-manager-rated competencies of graduate and diplomate nurses who had qualified up to three years previously. Instruments., A revised version of the Nursing Competencies Questionnaire was used to measure both overall competence and also eight specific nursing competencies. A shortened version of this scale was also used to assess internal consistency across measures. Two additional competencies, research awareness and policy awareness, were also measured. Results., Structural equation modelling found very little difference in the overall competence and specific competencies of graduates and diplomates. Where differences were found in the self-report data, diplomates scored more highly than graduates in the constructs of planning and social participation; however, these differences became non-significant when background variables were controlled for. Limitations., The findings are interpreted with caution due to the size of differences, the size of some of the samples of respondents and the developmental stage of the instrument used. Conclusions., It does not appear that graduates and diplomates in England differ in their level of competence to any great extent as measured by the Nursing Competencies Questionnaire. Areas of further work are discussed in the light of the findings. Relevance to clinical practice., While this may alleviate concerns about clinical disparities between the two groups, it raises questions about the proposed benefits to nursing of three-year preregistration degrees in terms of quality of care during the first three years of qualification. [source]

A computer attitude scale for computer science freshmen and its educational implications

G.E. Palaigeorgiou
Abstract The successful integration of computers in educational environments depends, to a great extent, on students' attitudes towards them. Widely used computer attitude scales (CASs) focus on the beliefs of typical computer users and do not reveal the more refined attitudes of groups that use computers extensively and develop unique relations with them. This study presents the development and validation of a CAS especially designed for computer science freshmen (CASF). The scale consists of five factors, namely, self-confidence in previous knowledge, hardware usage anxiety, computer engagement, fears of long-lasting negative consequences of computer use and evaluation of positive consequences of computers in personal and social life. Using an analytic computer experience construct, the scale's components were related to multiple aspects of students' computer experience. CASF responses can inform a variety of instructional decisions and classroom management strategies for the first phase of the students' studies. [source]


ABSTRACT The study of different strategies for prolonging the shelf life of fresh minced beef patties was addressed in this work. Fresh minced beef was supplemented with thymol (THY) at levels of 250, 500 and 750 mg per kg of ground beef. Treated samples were packed using a high barrier film and stored in refrigerated conditions (4C) under ordinary atmosphere packaging and modified atmosphere packaging (MAP) conditions for 16 days. The microbiological quality decay kinetic was determined by monitoring the following microorganisms: Enterobacteriaceae, Pseudomonas spp., lactic acid bacteria, Brochothrix thermosphacta, coliforms and total psychrotrophic viable count. Results show that THY, working alone, was effective on coliforms and Enterobacteriaceae, whereas it does not seem to inhibit to a great extent the growth of the other microbial populations. On the other hand, an increased amount of THY, under MAP conditions, had better effects on the product quality, with a consequent prolongation of the shelf life. PRACTICAL APPLICATIONS Great interest is developing in food bio-preservation, because of the ever-increasing needs to protect consumers' health and to valorize the naturalness and safety of food products. However, very few works have been carried out on the applications of bio-preservatives to extend the shelf life of fresh meat products. This study, therefore, was mainly initiated to evaluate the possibility of extending the shelf life of packed fresh meat patties by a combination of thymol (THY) to other extrinsic factors such as storage temperatures and modified atmosphere during packaging. Interesting results were obtained suggesting that THY can perform an efficient synergy with modified atmosphere conditions and could be advantageously utilized by the meat industry. [source]

Preservation of Microstructure in Peach and Mango during High-pressure-shift Freezing

L. Otero
ABSTRACT: A histological technique was used to evaluate modifications on the microstructure of peach and mango due to classical methods of freezing and those produced by high-pressure-shift freezing (HPSF). With the high-pressure-shift method, samples are cooled under pressure (200 MPa) to -20C without ice formation, then pressure is released to atmospheric pressure (0.1 MPa). The high level of supercooling (approximately 20C) leads to uniform and rapid ice nucleation throughout the volume of the specimen. This method maintained the original tissue structure to a great extent. Since problems associated with thermal gradients are minimized, high-pressure-shift freezing prevented quality losses due to freeze-cracking or large ice crystal presence. [source]

Mapping the characteristics of the radical ring-opening polymerization of a cyclic ketene acetal towards the creation of a functionalized polyester

Peter Plikk
Abstract Radical ring-opening polymerization of cyclic ketene acetals is a means to achieve novel types of aliphatic polyesters. 2-methylene-1,3-dioxe-5-pene is a seven-membered cyclic ketene acetal containing an unsaturation in the 5-position in the ring structure. The double bond functionality enables further reactions subsequent to polymerization. The monomer 2-methylene-1,3-dioxe-5-pene was synthesized and polymerized in bulk by free radical polymerization at different temperatures, to determine the structure of the products and propose a reaction mechanism. The reaction mechanism is dependent on the reaction temperature. At higher temperatures, ring-opening takes place to a great extent followed by a new cyclization process to form the stable five-membered cyclic ester 3-vinyl-1,4-butyrolactone as the main reaction product. Thereby, propagation is suppressed and only small amounts of other oligomeric products are formed. At lower temperatures, the cyclic ester formation is reduced and oligomeric products containing both ring-opened and ring-retained repeating units are produced at higher yield. 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4587,4601, 2009 [source]


ABSTRACT R -index is an important statistic for testing and measuring product effects. The validation and merits of R-index are to a great extent due to the fact that it is closely related to the famous Mann,Whitney U statistic. Based on this fortunate relationship, statistical analyses for R-index are explored. The statistical analyses include estimations of R-index and its null and nonconditional variances with and without assuming continuity of data; difference and similarity tests using R-index; powers and sample sizes for the tests; linking R-index with Thurstonian , (or d,). The new techniques developed in the paper extend greatly the original R-index analysis for categorical ratings data. It is expected that the recognition of the profound theoretical origin of R-index and the available statistical analyses for R-index will provide the impetus for the resurgence of interest in using R-index in sensory and consumer researches. [source]

Miracles of love: The use of metaphor in egg donor ads1

Pamela Hobbs
In recent years, the appearance of egg donor advertisements in American college newspapers, sometimes offering five- and six-figure fees to ,genetically gifted' donors, has given rise to critical comment on both sides of the Atlantic, and has caused some to fear that the use of these procedures will eventually result in the creation of ,designer babies' with preselected genetic qualities. Whether such fears will be realized depends, to a great extent, upon how both the participants themselves and society as a whole come to view and understand these procedures. This article explores emerging images of assisted reproduction through an analysis of the use of metaphor in egg donor ads that appeared in the student newspaper of the University of California, Los Angeles. I argue that the attitudes displayed in these ads result from a mapping of existing cultural stereotypes associated with biological parenthood, including the role of childbearing in marriage and ,coupledom', onto the assisted-reproduction process, and that these metaphors are used precisely because they construct this cultural model and adapt it to the new reality of the assisted-conception experience. [source]

Influence of amylases on the rheological and molecular properties of partially damaged wheat starch

Pedro Leman
Abstract The effects of Bacillus subtilis, porcine pancreatic and Aspergillus oryzae ,-amylases, sweet potato ,-amylase and Bacillus stearothermophilus maltogenic amylase (BStA) on the rheological properties (measured with a Rapid Visco Analyser) of partially damaged wheat starch were studied and the accompanying changes in starch molecular properties were analysed by high-performance size exclusion chromatography. Pasting and gelation of starch slurries (with an increased level of damaged starch) were significantly affected by the supplemented amylases and greatly depended on the mode of action and properties of the enzymes added. In general, at low endo-amylase concentrations, peak, hot paste and cold paste viscosities were more reduced for enzyme-supplemented partially damaged starch than for enzyme-supplemented native wheat starch, demonstrating the significance of damaged starch levels in determining amylase functionality. Higher dosages of thermostable amylases ruled out most of the differences between amylase-supplemented native starch and partially damaged starches, except for BStA. Furthermore, the (limited) endo-action of BStA determines to a great extent the rheological properties of the starch paste. These results contribute to a better understanding of (maltogenic) amylase functionality in processing (damaged) starch-containing foods. Copyright 2006 Society of Chemical Industry [source]

Inhibition of aflatoxin B1 production of Aspergillus flavus, isolated from soybean seeds by certain natural plant products

Y.L. Krishnamurthy
Abstract Aims:, The inhibitory effect of cowdung fumes, Captan, leaf powder of Withania somnifera, Hyptis suaveolens, Eucalyptus citriodora, peel powder of Citrus sinensis, Citrus medica and Punica granatum, neem cake and pongamia cake and spore suspension of Trichoderma harzianum and Aspergillus niger on aflatoxin B1 production by toxigenic strain of Aspergillus flavus isolated from soybean seeds was investigated. Methods and Results:, Soybean seed was treated with different natural products and fungicide captan and was inoculated with toxigenic strain of A. flavus and incubated for different periods. The results showed that all the treatments were effective in controlling aflatoxin B1 production. Captan, neem cake, spore suspension of T. harzianum, A. niger and combination of both reduced the level of aflatoxin B1 to a great extent. Leaf powder of W. somnifera, H. suaveolens, peel powder of C. sinensis, C. medica and pongamia cake also controlled the aflatoxin B1 production. Conclusions:, All the natural product treatments applied were significantly effective in inhibiting aflatoxin B1 production on soybean seeds by A. flavus. Significance and Impact of the Study:, These natural plant products may successfully replace chemical fungicides and provide an alternative method to protect soybean and other agricultural commodities from aflatoxin B1 production by A. flavus. [source]

Encapsulation and/or Release Behavior of Bovine Serum Albumin within and from Polylactide-Grafted Dextran Microspheres

Tatsuro Ouchi
Abstract Summary: Polylactide (PLA)-grafted dextran (Dex- graft -PLA) of various contents of sugar units was synthesized by anionic polymerization of L -lactide (L -LA) using the alkoxide of partially trimethylsilylated dextran (TMSDex) and subsequently removing the trimethylsilyl (TMS) groups. The copolymer showed different solubility from L -LA homopolymer with increasing the content of sugar units. We prepared bovine serum albumin (BSA)-loaded microspheres (MS)s according to a water-in-oil-in-water emulsion-solvent evaporation/extraction method using methylene chloride/DMSO as an organic cosolvent. MSs prepared from Dex- graft -PLA [MS(Dex- graft -PLA)s] exhibited higher loading efficiency of BSA than MSs prepared from PLLA [MS(PLLA)s]. The in vitro release rate of BSA from MS(Dex- graft -PLA) was faster than that from MS(PLLA). BSA released from MS(Dex- graft -PLA) maintained the secondary structure of native BSA to a great extent, compared with BSA released from MS(PLLA). Confocal fluorescence images of the differential interference micrographs over the fluorescence images of MS(PLLA) and MS(Dex- graft -PLA). [source]

Thermo-Responsive Organic/Inorganic Hybrid Hydrogels based on Poly(N -vinylcaprolactam)

Wouter Loos
Abstract A new type of ,intelligent' hydrogels has been developed in the form of organic/inorganic hybrid materials by making use of the sol-gel technology. Poly(N -vinylcaprolactam) (PVCL) has been incorporated in these materials for its thermo-responsive properties. The synthesis of the hybrid hydrogels was achieved by the in situ formation of an inorganic silica phase in the presence of an aqueous solution of high molecular weight PVCL. This methodology results in the preparation of micro-heterogeneous systems in which silica particles of nanometer dimensions act as physical cross-links for the PVCL molecules. Hydrogen bonds between the remaining non-condensed silanol groups and the PVCL carbonyl functions, together with physical entanglements, are responsible for the strong interactions between the organic and inorganic phases. Stress-strain tests on highly swollen materials demonstrated that the unique structure of these thermo-responsive hybrid hydrogels improves the mechanical stability to a great extent as compared to conventional hydrogels. Transmission measurements demonstrate that the presence of the inorganic phase does not influence the cloud point temperatures of PVCL significantly. On the other hand, the response of the reinforced hybrid hydrogels to temperature becomes less pronounced for increasing silica fractions. The reversibility of the swelling/deswelling process has been demonstrated by swelling experiments as a function of temperature. PVCL/SiO2 hybrid hydrogels. [source]

Proteome analysis of non-model plants: A challenging but powerful approach

Sebastien Christian Carpentier
Abstract Biological research has focused in the past on model organisms and most of the functional genomics studies in the field of plant sciences are still performed on model species or species that are characterized to a great extent. However, numerous non-model plants are essential as food, feed, or energy resource. Some features and processes are unique to these plant species or families and cannot be approached via a model plant. The power of all proteomic and transcriptomic methods, that is, high-throughput identification of candidate gene products, tends to be lost in non-model species due to the lack of genomic information or due to the sequence divergence to a related model organism. Nevertheless, a proteomics approach has a great potential to study non-model species. This work reviews non-model plants from a proteomic angle and provides an outline of the problems encountered when initiating the proteome analysis of a non-model organism. The review tackles problems associated with (i) sample preparation, (ii) the analysis and interpretation of a complex data set, (iii) the protein identification via MS, and (iv) data management and integration. We will illustrate the power of 2DE for non-model plants in combination with multivariate data analysis and MS/MS identification and will evaluate possible alternatives. 2008 Wiley Periodicals, Inc., Mass Spec Rev 27: 354,377, 2008 [source]