			Home About us Contact

Different Quality (different + quality)

Distribution by Scientific Domains

Life Sciences	37%
Chemistry	33%
Medical Sciences	22%
2 Other Domains	8%

Selected Abstracts

Effects of Screw Eccentricity on the Initial Stability of the Acetabular Cup in Artificial Foam Bone of Different Qualities

ARTIFICIAL ORGANS, Issue 1 2010
Jui-Ting Hsu
Abstract Acetabular cup loosening is one of the major failure models of total hip replacement (THR), which is mostly due to insufficient initial stability of the cup. Previous studies have demonstrated that cup stability is affected by the quality of the host bone and the surgical skill when inserting screws. The purpose of this study was to determine the effects on the initial stability of the acetabular cup of eccentric screws in bone of different qualities. In this study, hemispherical cups were fixed into bone specimens constructed from artificial foam with three elastic moduli using one to three screws. The effects of two types of screw eccentricity (offset and angular) on the stability of the acetabular cup were also evaluated. The experimental results indicate that in the presence of ideal screwing, the cup was stable in bone specimens constructed from foam with the highest elastic modulus. In addition, increasing the number of ideal screws enhanced the cup stability, especially in bone specimens constructed from soft foam. Moreover, the cup stability was most affected by offset eccentric screw(s) in the hard-foam bone specimens and by angular eccentric screw(s) in the soft-foam bone specimens. The reported results indicate that the presence of screw eccentricity affects the initial stability of the acetabular cup. Surgeons should keep this in mind when performing screw insertions in THR. However, care is necessary when translating these results to the intraoperative situation due to the experiments being conducted under laboratory conditions, and hence, future studies should attempt to replicate the results reported here in vivo. [source]

THE PRACTICE OF HIGHER EDUCATION: IN PURSUIT OF EXCELLENCE AND OF EQUITY

EDUCATIONAL THEORY, Issue 4 2006
David Bridges
He considers whether some of the changes in practices linked to the massification of higher education have in fact resulted in the breakdown of higher education as a practice, at least on Alasdair MacIntyre's definition of the term. Specifically, Bridges examines whether higher education has lost its sense of the forms of human excellence around which its life is constructed. Finally, he points to issues of equity raised by the huge variety of forms that higher education now takes and asks whether this variety might mean that students are winning entry to some very different qualities of experience when judged against the requirement that they should contribute to the development of human excellence. [source]

,Best research practice': in pursuit of methodological rigour

JOURNAL OF ADVANCED NURSING, Issue 3 2001
Frances Maggs-Rapport BA MPhil CertEd FRSA
,Best research practice': in pursuit of methodological rigour Rationale.,This paper is based on the rationale that misuse of methodological notions in research publications lays research studies open to criticism and dismissal. Aim.,In search of ,best research practice', this paper aims to examine the different qualities of four major qualitative methodologies: ethnography, descriptive phenomenology, interpretative phenomenology/hermeneutics and critical social theory. Design.,The study presents a critical overview of methodological decision-making, illustrating the sorts of issues researchers must consider in order to justify to the readership and to themselves the employment of a particular methodology. This is presented alongside a general overview of qualitative research and a précis of each of the major qualitative methodologies. The paper describes the methodologies, salient features, and examines methodological similarities and differences. The paper concludes by examining the need for methodological rigour within the framework of the National Health Service (NHS) Executive's drive for evidence-based practice in health care. Recommendations.,It is hoped that the paper will stimulate a deeper exploration of methodological rigour in future research publications. [source]

Phototropism of Thalli and Rhizoids Developed from the Thallus Segments of Bryopsis hypnoides Lamouroux

JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 6 2006
Nai-Hao Ye
Abstract Newly regenerated thalli were used to study the phototropism of Bryopsis hypnoides Lamouroux under different qualities of light. Positive phototropism in the thalli and negative phototropism in the rhizoids of B. hypnoides were investigated and analyzed in terms of bending. Both thalli and rhizoids developed from thallus segments exhibited typical tip growth, and their photoreceptive sites for phototropism were also restricted to the apical hemisphere. The bending curvature of rhizoids and thalli were determined with unilateral lights at various wavelengths and different fluence rates after a fixed duration of illumination. The trends of bending from the rhizoid and thallus were coincident, which showed that the action spectrum had a large range, from ultraviolet radiation (366.5 nm) to green light (524 nm). Based on the bending curvatures, blue light had the highest efficiency, while the efficiency of longer wavelengths (>500 nm) was significantly lower. External Ca2+ had no effect on the bending curvature of thalli and rhizoids. Blue light (440 nm) induced thallus branching from rhizoids, while red light (650 nm) had no such effect. Fast-occurring chloroplast accumulation in the outermost cytoplasmic layer of the blue light (440 nm)-irradiated region in the rhizoid was observed, from which protrusions (new thalli) arose after 4 h of the onset of illumination, and this action was thought to be driven by the dynamics of actin microfilaments. (Managing editor: Wei Wang) [source]

Study of two different cold restructuring processes using two different qualities of hake (Merluccius capensis) muscle, with addition of microbial transglutaminase

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2009
Helena M Moreno
Abstract BACKGROUND: Microbial transglutaminase (MTGase) can improve the mechanical and functional properties of restructured fish products without the need of thermal gelation. The present study seeks to determine whether, for different setting times, MTGase activity in restructured hake muscle made with pieces or with homogenised muscle can be affected by the quality of the protein in the raw materials. RESULTS: As regards mechanical properties, samples of both qualities subjected to the two different processes attained a suitable consistency after setting for 24 h at 5 °C. The quality of the protein in the sample is important when pieces are used for restructuring, but not when sample is homogenised. Also, there were strong correlations between residual MTGase activity up to 12 h and mechanical properties and electrophoretic band density. Water binding capacity (WBC) was not significantly altered by MTGase addition. CONCLUSION: The experimental combination of 10 g kg,1 of MTGase, 15 g kg,1 of sodium chloride and 7.5 g kg,1 of sodium caseinate was suitable for the production of minimally processed raw restructured fish products made with two different qualities of fish protein and two different restructuring processes. In the restructured products made with pieces, the protein quality significantly affected final properties, but in finely homogenised product the protein quality was less important. Copyright © 2009 Society of Chemical Industry [source]

A Comparison of ICD Implantations in the United States Versus Italy

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2007
STEVEN M. GREENBERG M.D.
Background: The benefits conferred by implantable cardioverter defibrillators (ICDs) have expanded to primary prevention. The advancements in ICD therapy (ACT) registry in the United States and the Italian ICD registry (IIR) examine changing trends in ICD implantation in their respective countries. Data from these registries may be useful for comparison of transcontinental differences in ICD utilization. Methods: This study includes initial implantations in patients enrolled in ACT and IIR. A comparative analysis was performed for device indications based on primary or secondary prevention. Sub-group analyses by device types (single, dual chamber, or cardiac resynchronization) were performed. Results: This analysis included 4,547 primary implantations in ACT and 6,491 in IIR. The groups were similar with respect to age. There were 82% primary and 18% secondary prevention indications in ACT, versus 42% primary and 58% secondary prevention indications in IIR (P < 0.001). There was a significantly higher rate of dual chamber ICD implants in ACT than in IIR for both primary (35.7% vs 23.7%, P < 0.001) and secondary prevention (52.3% vs 36.9%, P < 0.001). Conversely, more CRT-D were implanted in IIR than in ACT (primary prevention 46.5% vs 32.0%; secondary prevention 29.0% vs 13.0%, P < 0.001). Conclusions: Significant differences were observed in the types of indications for ICDs between ACT and IIR. Device prescription differed significantly between countries. The specific reasons for differences in ICD implantation patterns in these two countries are unclear. These observations warrant further investigations to determine if these differences are associated with different qualities of life and clinical outcomes. [source]

Effects of deep and superficial experimentally induced acute pain on muscle sympathetic nerve activity in human subjects

THE JOURNAL OF PHYSIOLOGY, Issue 1 2009
A. R. Burton
Human studies conducted more than half a century ago have suggested that superficial pain induces excitatory effects on the sympathetic nervous system, resulting in increases in blood pressure (BP) and heart rate (HR), whereas deep pain is believed to cause vasodepression. To date, no studies have addressed whether deep or superficial pain produces such differential effects on muscle sympathetic nerve activity (MSNA). Using microneurography we recorded spontaneous MSNA from the common peroneal nerve in 13 awake subjects. Continuous blood pressure was recorded by radial arterial tonometry. Deep pain was induced by intramuscular injection of 0.5 ml hypertonic saline (5%) into the tibialis anterior muscle, superficial pain by subcutaneous injection of 0.2 ml hypertonic saline into the overlying skin. Muscle pain, with a mean rating of 4.9 ± 0.8 (s.e.m.) on a 0,10 visual analog scale (VAS) and lasting on average 358 ± 32 s, caused significant increases in MSNA (43.9 ± 10.0%), BP (5.4 ± 1.1%) and HR (7.0 ± 2.0%) , not the expected decreases. Skin pain, rated at 4.9 ± 0.6 and lasting 464 ± 54 s, also caused significant increases in MSNA (38.2 ± 12.8%), BP (5.1 ± 2.1%) and HR (5.6 ± 2.0%). The high-frequency (HF) to low-frequency (LF) ratio of heart rate variability (HRV) increased from 1.54 ± 0.25 to 2.90 ± 0.45 for muscle pain and 2.80 ± 0.52 for skin pain. Despite the different qualities of deep (dull and diffuse) and superficial (burning and well-localized) pain, we conclude that pain originating in muscle and skin does not exert a differential effect on muscle sympathetic nerve activity, both causing an increase in MSNA and an increase in the LF : HF ratio of HRV. Whether this holds true for longer lasting experimental pain remains to be seen. [source]

Effects of Screw Eccentricity on the Initial Stability of the Acetabular Cup in Artificial Foam Bone of Different Qualities

Simultaneous determination of eight major steroids from Polyporus umbellatus by high-performance liquid chromatography coupled with mass spectrometry detections

BIOMEDICAL CHROMATOGRAPHY, Issue 2 2010
Ying-yong Zhao
Abstract Polyporus umbellatus is a widely used diuretic herbal medicine. In this study, a high-performance liquid chromatography coupled with atmospheric pressure chemical ionization,mass spectrometric detection (HPLC-APCI-MS) method was developed for qualitative and quantitative analysis of steroids, as well as for the quality control of Polyporus umbellatus. The selectivity, reproducibility and sensitivity were compared with HPLC with photodiode array detection and evaporative light scattering detection (ELSD). Selective ion monitoring in positive mode was used for qualitative and quantitative analysis of eight major components and ,-ecdysterone was used as the internal standard. Limits of detection and quantification fell in the ranges 7,21 and 18,63 ng/mL for the eight analytes with an injection of 10 µL samples, and all calibration curves showed good linear regression (r2 > 0.9919) within the test range. The quantitative results demonstrated that samples from different localities showed different qualities. Advantages, in comparison with conventional HPLC,diode array detection and HPLC-ELSD, are that reliable identification of target compounds could be achieved by accurate mass measurements along with characteristic retention time, and the great enhancement in selectivity and sensitivity allows identification and quantification of low levels of constituents in complex Polyporus umbellatus matrixes. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Formation of buyer-seller trade networks in a quality-differentiated product market

CANADIAN JOURNAL OF ECONOMICS, Issue 3 2006
Ping Wang
Abstract We examine the formation of buyer-seller links when exchange can take place only if such a link exists. Sellers produce products of different qualities, and multiple sellers can form a sellers' association to pool their customers setting uniform prices. Buyers form trade links with individual sellers or sellers' associations. We show which buyer-seller links will form and find the set of links that are stable and show how these links influence prices. We also show that a trade network mismatch may occur where a high-quality good remains unsold even without an economy-wide excess supply of goods. Les auteurs examinent le processus de formation de liens acheteurs-vendeurs quand l'échange ne peut s'effectuer que si de tels liens existent. Les vendeurs produisent des biens de différentes qualités et un nombre de vendeurs peuvent former une association pour mettre en commun leurs clients et imposer des prix uniformes. Les acheteurs forment des liens commerciaux avec des vendeurs individuels ou avec leurs associations. On montre quels liens acheteurs-vendeurs vont se former, quels liens vont s'avérer stables, et comment ces liens influencent le niveau des prix. On montre aussi qu'un réseau de commerce peut être mal adapté et un bien de haute qualité resté sans preneur même s'il n'y a pas offre excédentaire de biens dans toute l'économie. [source]

Immediate early gene (ZENK, Arc) expression in the auditory forebrain of female canaries varies in response to male song quality

DEVELOPMENTAL NEUROBIOLOGY, Issue 3 2005
Stefan Leitner
Abstract In male songbirds, the song control pathway in the forebrain is responsible for song production and learning, and in females it is associated with the perception and discrimination of male song. However, experiments using the expression of immediate early genes (IEGs) reveal the activation of brain regions outside the song control system, in particular the caudomedial nidopallium (NCM) and the caudomedial mesopallium (CMM). In this study on female canaries, we investigate the role of these two regions in relation to playback of male songs of different quality. Male canaries produce elaborate songs and some contain syllables with a more complex structure (sexy syllables) that induce females to perform copulation solicitation displays (CSD) as an invitation to mate. Females were first exposed to playback of a range of songs of different quality, before they were finally tested with playback of songs containing either sexy or nonsexy syllables. We then sectioned the brains and used in situ hybridization to reveal brain regions that express the IEGs ZENK or Arc. In CMM, expression of ZENK mRNA was significantly higher in females that last heard sexy syllables compared to those that last heard nonsexy syllables, but this was not the case for NCM. Expression of Arc mRNA revealed no differences in either CMM or NCM in both experimental groups. These results provide evidence that in female canaries CMM is involved in female perception and discrimination of male song quality through a mechanism of memory reconsolidation. The results also have further implications for the evolution of complex songs by sexual selection and female choice. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005 [source]

Female canaries that respond and discriminate more between male songs of different quality have a larger song control nucleus (HVC) in the brain

DEVELOPMENTAL NEUROBIOLOGY, Issue 4 2002
Stefan Leitner
Abstract In male songbirds the song control pathway in the forebrain is responsible for song production and learning. In most species, females do not sing and have smaller nuclei in the song control pathway. Although the function of the pathway in females is assumed to be associated with the perception of male song, there is little direct evidence to support this view. In this study on female canaries, we investigate the role of two key nuclei in the song control pathway (HVC and lMAN) in relation to playback of male song. Male canaries produce elaborate songs that function to attract and stimulate females. The songs are constructed from smaller units called syllables, and special syllables with a more complex structure (sexy syllables) are known to induce females to perform copulation solicitation displays (CSD) as an invitation to mate. By using computer-edited experimental songs, we first show that females discriminate between songs by producing significantly more CSD to those containing sexy syllables. We then sectioned the brains and used in situ hybridization to reveal song nuclei containing androgen receptors. We report positive correlations between the size of HVC and both total CSD response and the amount of discrimination between sexy and nonsexy songs. We found no such relationships between these measures and the size of lMAN. These results provide some evidence to support the view that, in female canaries HVC is involved in female perception and discrimination of male song. The results also have implications for the evolution of complex male songs by sexual selection and female choice. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 294,301, 2002 [source]

Insulin therapy in type 2 diabetes: what is the evidence?

DIABETES OBESITY & METABOLISM, Issue 5 2009
Mariëlle J. P. Van Avendonk
Aim:, To systematically review the literature regarding insulin use in patients with type 2 diabetes mellitus Methods:, A Medline and Embase search was performed to identify randomized controlled trials (RCT) published in English between 1 January 2000 and 1 April 2008, involving insulin therapy in adults with type 2 diabetes mellitus. The RCTs must comprise at least glycaemic control (glycosylated haemoglobin (HbA1c), postprandial plasma glucose and /or fasting blood glucose (FBG)) and hypoglycaemic events as outcome measurements. Results:, The Pubmed search resulted in 943 hits; the Embase search gave 692 hits. A total of 116 RCTs were selected by title or abstract. Eventually 78 trials met the inclusion criteria. The studies were very diverse and of different quality. They comprised all possible insulin regimens with and without combination with oral medication. Continuing metformin and/or sulphonylurea after start of therapy with basal long-acting insulin results in better glycaemic control with less insulin requirements, less weight gain and less hypoglycaemic events. Long-acting insulin analogues in combination with oral medication are associated with similar glycaemic control but fewer hypoglycaemic episodes compared with NPH insulin. Most of the trials demonstrated better glycaemic control with premix insulin therapy than with a long-acting insulin once daily, but premix insulin causes more hypoglycaemic episodes. Analogue premix provides similar HbA1c, but lower postprandial glucose levels compared with human premix, without increase in hypoglycaemic events or weight gain. Drawing conclusions from the limited number of studies concerning basal,bolus regimen seems not possible. Some studies showed that rapid-acting insulin analogues frequently result in a better HbA1c or postprandial glucose without increase of hypoglycaemia than regular human insulin. Conclusion:, A once-daily basal insulin regimen added to oral medication is an ideal starting point. All next steps, from one to two or even more injections per day should be taken very carefully and in thorough deliberation with the patient, who has to comply with such a regimen for many years. [source]

Adjustment of Parental Investment in the Dung Beetle Onthophagus atripennis (Col., Scarabaeidae)

ETHOLOGY, Issue 12 2006
Shigeki Kishi
If parents can invest resources optimally per offspring, they should adjust the amount of investment in an offspring according to environmental heterogeneity. Many studies have demonstrated changes in egg size or the amount of resource supplied in response to environmental heterogeneity. However, it remains unclear whether parents simply know the resource type a priori or can assess resource quality and adjust the quantity of investment accordingly. We examined the parental capability to adjust the amount of investment per offspring by providing Onthophagus atripennis dung beetle parents with one of three dung types of different quality: monkey dung (high quality), cow dung (low quality), or a mixture of monkey and cow dung (medium quality). The beetle parents cooperatively produce dung brood masses each with one egg under the ground. The size of a brood mass, on which a larva can only feed until adult, represents a large part of the amount of investment. Parents produced a greater number of smaller brood masses given high-quality resource, while they compensated for low quality of the resource by providing a larger amount of the resource, at the cost of offspring number. However, despite this compensation in the amount of food, offspring raised on low-quality food was still smaller than offspring raised on high-quality food. Thus, O. atripennis parents assessed resource quality partly and adjusted the amount of resource provided for their offspring. [source]

Rearing conditions determine offspring survival independent of egg quality: a cross-foster experiment with Oystercatchers Haematopus ostralegus

IBIS, Issue 2 2006
MARTIJN VAN DE POL
Variation in rearing conditions, due either to parental or to environmental quality, can result in offspring of different quality (e.g. body condition, immune function). However, evidence is accumulating that egg size and composition can also affect offspring quality. In Oystercatchers Haematopus ostralegus, high-quality rearing conditions result in a higher quantity as well as quality of offspring. This is thought to be caused by increased parental food provisioning to the chicks in high-quality environments. However, variation in egg quality between rearing conditions could also affect the quantity and quality of offspring. Determining the mechanism and ontogeny of quality differences is important in unravelling the causes of variation in reproductive success. To disentangle the effects of egg quality, and quality of the rearing conditions, on the future survival of offspring, we cross-fostered complete clutches between nests. When reared under conditions of similar environmental quality, chicks originating from eggs laid in low-quality environments survived as well as chicks originating from eggs laid in a high-quality environment. However, chicks reared in high-quality environments survived twice as long as chicks reared in low-quality environments, independent of the environmental quality in which the eggs were laid. This suggests that variation in the future survival of offspring is primarily caused by differences in environmental and/or parental quality, with no clear effect of egg quality (size). [source]

Habitat-specific demography and source,sink dynamics in a population of Siberian jays

JOURNAL OF ANIMAL ECOLOGY, Issue 1 2010
Magdalena Nystrand
Summary 1.,There are a number of models describing population structure, many of which have the capacity to incorporate spatial habitat effects. One such model is the source,sink model, that describes a system where some habitats have a natality that is higher than mortality (source) and others have a mortality that exceeds natality (sink). A source can be maintained in the absence of migration, whereas a sink will go extinct. 2.,However, the interaction between population dynamics and habitat quality is complex, and concerns have been raised about the validity of published empirical studies addressing source,sink dynamics. In particular, some of these studies fail to provide data on survival, a significant component in disentangling a sink from a low quality source. Moreover, failing to account for a density-dependent increase in mortality, or decrease in fecundity, can result in a territory being falsely assigned as a sink, when in fact, this density-dependent suppression only decreases the population size to a lower level, hence indicating a ,pseudo-sink'. 3.,In this study, we investigate a long-term data set for key components of territory-specific demography (mortality and reproduction) and their relationship to habitat characteristics in the territorial, group-living Siberian jay (Perisoreus infaustus). We also assess territory-specific population growth rates (r), to test whether spatial population dynamics are consistent with the ideas of source,sink dynamics. 4.,Although average mortality did not differ between sexes, habitat-specific mortality did. Female mortality was higher in older forests, a pattern not observed in males. Male mortality only increased with an increasing amount of open areas. Moreover, reproductive success was higher further away from human settlement, indicating a strong effect of human-associated nest predators. 5.,Averaged over all years, 76% of the territories were sources. These territories generally consisted of less open areas, and were located further away from human settlement. 6.,The source,sink model provides a tool for modelling demography in distinct habitat patches of different quality, which can aid in identifying key habitats within the landscape, and thus, reduce the risk of implementing unsound management decisions. [source]

Rain forest promotes trophic interactions and diversity of trap-nesting Hymenoptera in adjacent agroforestry

JOURNAL OF ANIMAL ECOLOGY, Issue 2 2006
ALEXANDRA-MARIA KLEIN
Summary 1Human alteration of natural ecosystems to agroecosystems continues to accelerate in tropical countries. The resulting world-wide decline of rain forest causes a mosaic landscape, comprising simple and complex agroecosystems and patchily distributed rain forest fragments of different quality. Landscape context and agricultural management can be expected to affect both species diversity and ecosystem services by trophic interactions. 2In Central Sulawesi, Indonesia, 24 agroforestry systems, differing in the distance to the nearest natural forest (0,1415 m), light intensity (37·5,899·6 W/m,2) and number of vascular plant species (7,40 species) were studied. Ten standardized trap nests for bees and wasps, made from reed and knotweed internodes, were exposed in each study site. Occupied nests were collected every month, over a period totalling 15 months. 3A total of 13 617 brood cells were reared to produce adults of 14 trap-nesting species and 25 natural enemy species, which were mostly parasitoids. The total number of species was affected negatively by increasing distance from forest and increased with light intensity of agroforestry systems. The parasitoids in particular appeared to benefit from nearby forests. Over a 500-m distance, the number of parasitoid species decreased from eight to five, and parasitism rates from 12% to 4%. 4The results show that diversity and parasitism, as a higher trophic interaction and ecosystem service, are enhanced by (i) improved connectivity of agroecosystems with natural habitats such as agroforestry adjacent to rain forest and (ii) management practices to increase light availability in agroforestry, which also enhances richness of flowering plants in the understorey. [source]

Habitat fragmentation and adaptation: a reciprocal replant,transplant experiment among 15 populations of Lychnis flos-cuculi

JOURNAL OF ECOLOGY, Issue 5 2008
Gillianne Bowman
Summary 1Habitat fragmentation and variation in habitat quality can both affect plant performance, but their effects have rarely been studied in combination. We thus examined plant performance in response to differences in habitat quality for a species subject to habitat fragmentation, the common but declining perennial herb Lychnis flos-cuculi. 2We reciprocally transplanted plants between 15 fen grasslands in north-east Switzerland and recorded plant performance for 4 years. 3Variation between the 15 target sites was the most important factor and affected all measures of plant performance in all years. This demonstrates the importance of plastic responses to habitat quality for plant performance. 4Plants from smaller populations produced fewer rosettes than plants from larger populations in the first year of the replant,transplant experiment. 5Plant performance decreased with increasing ecological difference between grassland of origin and target grassland, indicating adaptation to ecological conditions. In contrast, plant performance was not influenced by microsatellite distance and hardly by geographic distance between grassland of origin and target grassland. 6Plants originating from larger populations were better able to cope with larger ecological differences between transplantation site and site of origin. 7Synthesis: In addition to the direct effects of target grasslands, both habitat fragmentation, through reduced population size, and adaptation to habitats of different quality, contributed to the performance of L. flos-cuculi. This underlines that habitat fragmentation also affects species that are still common. Moreover, it suggests that restoration projects involving L. flos-cuculi should use plant material from large populations living in habitats similar to the restoration site. Finally, our results bring into question whether plants in small habitat remnants will be able to cope with future environmental change. [source]

Prediction of Microbial and Sensory Quality of Cold Smoked Atlantic Salmon (Salmo salar) by Electronic Nose

JOURNAL OF FOOD SCIENCE, Issue 9 2005
Gudrun Olafsdottir
ABSTRACT: Quality changes of cold smoked salmon from 4 different smokehouses in Europe were monitored by a prototype gas-sensor array system, the FishNose. Samples were stored in different packaging (vacuum and Modified Atmosphere Packaging [MAP]) for up to 4 wk under controlled storage conditions at 5 °C and 10 °C. Quality criteria based on sensory attributes (sweet/sour, off, and rancid odor), and total viable counts and lactic acid bacteria counts were established and used for classification of samples based on the responses of the FishNose. The responses of the gas-sensors correlated well with sensory analysis of spoilage odor and microbial counts suggesting that they can detect volatile microbially produced compounds causing spoilage odors in cold-smoked salmon during storage. The system is therefore ideal for fast quality control related to freshness evaluation of smoked salmon products. Partial least squares (PLS) regression models based on samples from single producer showed better performance than a global model based on products from different producers to classify samples of different quality. [source]

Analysing the contribution of component cultivars and cultivar combinations to malting quality, yield and disease in complex mixtures

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2008
Adrian C Newton
Abstract BACKGROUND: Mixtures of cereal cultivars grown together generally enhance yield and reduce disease but end-users will not accept them for quality uses. Some combinations with very different quality may be problematic, others complementary. The common origin of Maris Otter for quality in winter barley may enable the benefits of complex mixtures to be exploited without quality compromises. RESULTS: Seven winter barley cultivar monocultures and all their equal proportion mixtures were trialled and data analysed by ANOVA, REML and principal component analyses to determine the contribution of particular varieties or combinations to crop performance. Agronomic yield was positively correlated with component number. Pipkin contributed negatively to thousand grain weight (TGW), but positively to several quality traits; Gleam negatively to the same quality traits but strongly positively to yield; and Melanie combined strong yield and TGW characteristics with neutral quality traits. Interactions in mixtures with Maris Otter, from which most of the cultivars are likely to derive some of their quality traits, were less apparent for quality than for yield. CONCLUSIONS: Complex mixtures gave yield benefits generally without compromising quality, and analysis methods were developed to identify the beneficial or negative effects of component cultivars on malting quality traits, thereby providing data for optimising mixtures design. Copyright © 2008 Society of Chemical Industry [source]

Evaluation and applicability of a purification method coupled with nested PCR for the detection of Toxoplasma oocysts in water

LETTERS IN APPLIED MICROBIOLOGY, Issue 5 2006
C. Kourenti
Abstract Aims:, To describe the development, evaluation and applicability of a complete method for the detection of Toxoplasma gondii in water. Methods and Results:, The method incorporated concentration of water samples by Al2(SO4)3 -flocculation, purification by discontinuous sucrose gradients and detection of toxoplasmic DNA by 18S-rRNA nested PCR. Tap water replicates and natural water samples were seeded with defined numbers of Toxoplasma oocysts and processed for evaluation studies. When applied to environmental samples, the method gave highest detection sensitivities of 100 oocysts in river water and 10 oocysts in well- and sea water. The method was finally applied in 60 water samples of different quality and origin collected over a 14-month period. Toxoplasmic DNA was detected in four samples. Conclusions:, The method offers an alternative towards improving current methods that can be used for the detection of Toxoplasma oocysts in environmental water samples. Significance and Impact of the Study:, The method in its current form will be helpful for assessment of Toxoplasma contamination in water resources, particularly after outbreak events. [source]

Real-life applications of the MULVADO software package for processing DOSY NMR data

MAGNETIC RESONANCE IN CHEMISTRY, Issue 2 2006
R. Huo
Abstract MULVADO is a newly developed software package for DOSY NMR data processing, based on multivariate curve resolution (MCR), one of the principal multivariate methods for processing DOSY data. This paper will evaluate this software package by using real-life data of materials used in the printing industry: two data sets from the same ink sample but of different quality. Also a sample of an organic photoconductor and a toner sample are analysed. Compared with the routine DOSY output from monoexponential fitting, one of the single channel algorithms in the commercial Bruker software, MULVADO provides several advantages. The key advantage of MCR is that it overcomes the fluctuation problem (non-consistent diffusion coefficient of the same component). The combination of non-linear regression (NLR) and MCR can yield more accurate resolution of a complex mixture. In addition, the data pre-processing techniques in MULVADO minimise the negative effects of experimental artefacts on the results of the data. In this paper, the challenges for analysing polymer samples and other more complex samples will also be discussed. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Critical assessment of the applicability of gas chromatography-combustion-isotope ratio mass spectrometry to determine amino sugar dynamics in soil

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 8 2009
Charlotte Decock
Amino sugars in soils have been used as markers of microbial necromass and to determine the relative contribution of bacterial and fungal residues to soil organic matter. However, little is known about the dynamics of amino sugars in soil. This is partly because of a lack of adequate techniques to determine ,turnover rates' of amino sugars in soil. We conducted an incubation experiment where 13C-labeled organic substrates of different quality were added to a sandy soil. The objectives were to evaluate the applicability of compound-specific stable isotope analysis via gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) for the determination of 13C amino sugars and to demonstrate amino sugar dynamics in soil. We found total analytical errors between 0.8 and 2.6, for the ,13C-values of the soil amino sugars as a result of the required ,13C-corrections for isotopic alterations due to derivatization, isotopic fractionation and analytical conditions. Furthermore, the ,13C-values of internal standards in samples determined via GC-C-IRMS deviated considerably from the ,13C-values of the pure compounds determined via elemental analyzer IRMS (with a variation of 9 to 10, between the first and third quartile among all samples). This questions the applicability of GC-C-IRMS for soil amino sugar analysis. Liquid chromatography-combustion-IRMS (LC-C-IRMS) might be a promising alternative since derivatization, one of the main sources of error when using GC-C-IRMS, is eliminated from the procedure. The high 13C-enrichment of the substrate allowed for the detection of very high 13C-labels in soil amino sugars after 1 week of incubation, while no significant differences in amino sugar concentrations over time and across treatments were observed. This suggests steady-state conditions upon substrate addition, i.e. amino sugar formation equalled amino sugar decomposition. Furthermore, higher quality substrates seemed to favor the production of fungal-derived amino sugars. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Assessing in vivo Fertilizing Capacity of Liquid-Preserved Boar Semen According to the ,Hanover Gilt Model'

REPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2003
F Ardón
Contents The goal of this study was to determine the ability of the Hanover gilt model to assess in vivo fertilizing capacity of preserved sperm and to consider whether any modifications to this model were needed. This model evaluates the fertilizing capacity of semen based on the fertilization rate, the rate of normal embryos and the accessory sperm count of 3,5-day embryos. Its distinguishing characteristics are the use of one-time insemination of sperm in reduced numbers, of spontaneously ovulating gilts and of ovulation detection through ultrasound examination of ovaries. Reduced sperm numbers allow for an accurate evaluation of the fertilizing potential of different semen treatments, thereby avoiding the compensatory effect of doses calibrated to maximize fertility. The model's usefulness was assessed in a trial run designed to compare the fertilizing capacity of liquid boar semen diluted into two different extenders. The diluent, the boar and the backflow, had no significant effect on any of the parameters studied. Gilts inseminated less than 24 h before ovulation had a significantly higher (p < 0.01) fertilization rate and accessory sperm cell count (p < 0.05) than those inseminated more than 24 h before ovulation. Very good/good embryos from homogeneous litters (only very good/good embryos were present) had a significantly higher (p < 0.01) accessory sperm count than those from heterogeneous litters (at least one embryo was of a different quality and/or oocytes were present). Both very good/good and degenerated/retarded embryos from heterogeneous litters had low accessory sperm numbers. This suggests that accessory sperm count is significantly related to the quality of the litter, but not to the quality of the embryo within gilts. It can be concluded that the Hanover gilt model is sensitive enough to show fertility differences (in this study, those associated with in vivo ageing of semen), while using relatively few gilts and little time. [source]

Crystallization and preliminary X-ray diffraction analysis of inositol 1,3,4,5,6-pentakisphosphate kinase from Arabidopsis thaliana

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 1 2010
Jose Ignacio Baños-Sanz
Inositol 1,3,4,5,6-pentakisphosphate kinase (IP5 2-K) is an enzyme involved in inositol metabolism that synthesizes IP6 (inositol 1,2,3,4,5,6-hexakisphosphate) from inositol 1,3,4,5,6-pentakisphosphate (IP5) and ATP. IP6 is the major phosphorus reserve in plants, while in mammals it is involved in multiple cellular events such as DNA editing and chromatin remodelling. In addition, IP6 is the precursor of other highly phosphorylated inositols which also play highly relevant roles. IP5 2-K is the only enzyme that phosphorylates the 2-OH axial position of the inositide and understanding its molecular mechanism of substrate specificity is of great interest in cell biology. IP5 2-K from Arabidopsis thaliana has been expressed in Escherichia coli as two different fusion proteins and purified. Both protein preparations yielded crystals of different quality, always in the presence of IP6. The best crystals obtained for X-ray crystallographic analysis belonged to space group P212121, with unit-cell parameters a = 58.124, b = 113.591, c = 142.478,Å. Several diffraction data sets were collected for the native enzyme and two heavy-atom derivatives using a synchrotron source. [source]

Ambiphilicity of Dichlorosilylene in a Single Molecule

CHEMISTRY - A EUROPEAN JOURNAL, Issue 1 2010
Rajendra
SiCl2as a simultaneous ,-donor and -acceptor: The reaction of the Lewis base stabilized dichlorosilylene L,SiCl2 with B(C6F5)3 (L=imidazol-2-ylidene derivative) afforded the first silylene donor acceptor L,SiCl2,B(C6F5)3 complex (shown here). Charge density analysis revealed that the two C,Si and Si,B donor bonds are of considerably different quality. However, plain bond length consideration might suggest simple CSi and SiB single bonds. [source]