bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Dietary Fiber and Growth Hormone on Colonic Adaptation in Short Bowel Syndrome Treated by Enteral Nutrition
Authors: Xu Jianmin , Zhong Yunshi , Jin Dayong , Zhang Hongwei , Wu Zhaohan 
Published: May 2008

AbstractBackgroundColon adaptation can partially compensate for the reduced capacity of nutrient absorption in patients with short bowel syndrome (SBS).ObjectiveThe aim of this study was to assess the effect of combined treatment with enteral nutrition (EN), dietary fiber, and recombinant human growth hormone (rhGH) on promoting colonic adaptation.MethodsA group of 40 male Sprague‐Dawley rats undergoing up to 80% to 85% small intestine resection were randomly assigned to four groups of 10 rats each: enteral nutrition (EN, the control); enteral nutrition/dietary fiber (EF); enteral nutrition/rhGH (EG); and enteral nutrition/dietary fiber/rhGH (EFG). All groups received isonitrogenous, isocaloric enteral feeding for 21 days. Body weight, daily nitrogen balance, colonic morphology, DNA, insulin‐like growth factor‐1/IGF‐1 receptor (IGF‐1)/IGF‐1R) expression were determined.ConclusionMorphologic adaptation of the colon (including increased mucosal thickness and plica height, enlarged surface area, increased hyditloid cells) was observed on postoperative day 21. GH is superior to fiber in several aspects: increasing colon diameters (0.46 ± 0.03 vs. 0.38 ± 0.02 cm, P < 0.05), villous height (356 ± 23 vs. 307 ± 21 μm, P < 0.05) and total surface area (15,222 ± 1344 vs. 13,178 ± 1727 μm2, P < 0.05). Increased DNA content—1.66 ± 0.13 (EG) and 1.71 ± 0.13 (EGF) vs. 1.28 ± 0.11(EF), P < 0.05—in the colon was also found in the EG and EGF groups. GH administration led to a significant increase in plasma IGF‐1 (439.6 ± 88.3 ng/ml in the EG group, 455.4 ± 107.4 ng/ml in the EGF group) and growth hormone (9.29 ± 6.49 ng/ml in the EG group, 9.68 ± 3.26 ng/ml in the EGF group) as compared to the EN group (IGF‐1, 328.7 ± 68.1 ng/ml; GH, 5.81 ± 2.41 ng/ml) and the EF group (IGF‐1, 356.4 ± 52.1 ng/ml; GH, 6.51 ± 4.66 ng/ml). Analysis of IGF‐1 and IGF‐1 receptor mRNA also demonstrated a significantly higher IGF‐1 mRNA in the EG and EFG groups than in the EN and EF groups. Colon functional adaptation was also associated with accelerated absorptive function of water in the EF, EG, and EGF groups. Improved nutritional status (body weight, nitrogen retention, plasma protein) were seen in the EG and EGF groups. Dietary fiber, in combination with growth factor, synergistically promoted colon adaptation in the SBS animal model and facilitated maintenance of daily nutritional needs in rodents.
Influence of Fatty Acid Profile of Total Parenteral Nutrition Emulsions on the Fatty Acid Composition of Different Tissues of Piglets
Authors: Amusquivar E. , Sánchez M. , Hyde M. J. , Laws J. , Clarke L. , Herrera E. 
Published: May 2008

AbstractTotal parenteral nutrition (TPN) studies in human babies of very‐low‐birth‐weight suggest that the lipid emulsions currently available are not optimum for neonatal nutrition. Since fatty acid metabolism in human and pigs is very similar, the present study examines how lipid emulsions used in clinical TPN (i.e. ClinOleic, Intralipid, Lipofundin or Omegaven), with different fatty acid compositions, administered to neonatal piglets for 7 days, influenced their tissue fatty acid composition as compared to those enterally fed with a sow milk replacer. A positive linear relationship was found between the proportion of all individual fatty acids in the lipid emulsions or in the milk replacer versus those in plasma, skeletal muscle, subcutaneous fat, liver, heart, pancreas, stomach or intestine total lipids or in brain phospholipids, the latter showing the lowest correlation coefficient. With the exception of brain, the proportion of either oleic acid or α‐linolenic acid in the individual tissues was correlated with those present in the corresponding lipid emulsion or milk replacer, whereas the proportion of linoleic acid correlated significantly with all the tissues studied. With the exception of brain phospholipids, both eicosapentaenoic and docosahexaenoic acids were higher in the tissues of piglets receiving Omegaven than in all other groups. In conclusion, with the exception of the brain, fatty acid composition of plasma and different tissues in piglets are strongly influenced by the fatty acid profile of TPN emulsions. Fatty acid composition of brain phospholipids are, however, much less influenced by dietary composition, indicating an active and efficient metabolism that ensures its appropriate composition at this key stage of development.
Phase Transition of Sunflower Oil as Affected by the Oxidation Level
Authors: Calligaris Sonia , Arrighetti Gianmichele , Barba Luisa , Nicoli Maria Cristina 
Published: May 2008

AbstractThe influence of the oxidation level on the phase transition behavior of sunflower oil was evaluated by differential scanning calorimetry (DSC) and synchrotron X‐ray diffraction (XRD) at both small and wide angles. The crystallization was monitored at a cooling/heating rate of 2 °C/min from 20 to −80 °C and vice versa applying both techniques. The triacylglycerols organize in two double‐chain length structures: α 2L (61.87 Å) and β′ 2L (82.89 Å). The crystalline structure changes upon oxidation. In particular, the intensity of the XRD peak associated with the double‐chain structure of β′, as well as its crystallization and melting enthalpy, significantly decreases as the oxidation level increases.
Standing waves for nonlinear Schrödinger equations with singular potentials
Authors: Byeon Jaeyoung , Wang Zhi-Qiang 
Published: May 2008

We study semiclassical states of nonlinear Schrödinger equations with anisotropic type potentials which may exhibit a combination of vanishing and singularity while allowing decays and unboundedness at infinity. We give existence of spike type standing waves concentrating at the singularities of the potentials.

Résumé
Nous étudions les états semi-classiques des équations de Schrödinger non linéaires avec potentiels de type anisotropiques qui peuvent tendre vers zéro à l'infini, pour lesquels des phénomènes d'évanescence et de singularité sont possibles. Nous donnons l'existence d'ondes stationnaires se concentrant aux singularités des potentiels.
Medication adherence in patients with chronic non‐malignant pain: Is there a problem?
Authors: Broekmans Susan , Dobbels Fabienne , Milisen Koen , Morlion Bart , Vanderschueren Steven 
Published: May 2008

ABSTRACTHealth care providers, treating patients with chronic non‐malignant pain, often experience that medication is not as effective as expected. It is important to realize that the effectiveness of a pharmacological treatment can be influenced by the way the medication is taken. Medication adherence is a topic that gains more attention, especially in chronic conditions, because it affects treatment outcome. A systematic review of studies on medication adherence in patients with chronic non‐malignant pain was performed to gain insight in the prevalence of the problem, the impact on treatment outcome, influencing variables and interventions. Searching several electronic databases (Medline, CINAHL, Psychinfo and Cochrane), 14 relevant articles were found. The results indicate that medication non‐adherence is common in patients with chronic non‐malignant pain. Both overuse and underuse of medication occurs. However, due to the scarce literature and important methodological limitations, it is not possible to make firm conclusions concerning the impact on outcome, influencing variables and optimal intervention strategies. This review highlights some important gaps in the adherence literature in a chronic non‐malignant pain population and sets the stage for future research.
An analysis of the impact of timberland, farmland and commercial real estate in the asset allocation decisions of institutional investors
Authors: Waggle Doug , Johnson Don T. 
Published: May 2008

AbstractWe examine the effects of including timberland, farmland and commercial real estate in a mixed asset portfolio with stocks, government bonds and T‐Bills. Using both smoothed and unsmoothed returns (as per Geltner [Geltner, D. (1993). Estimating market values from appraised values without assuming an efficient market. Journal of Real Estate Research, 8, 25–345.]) and both constrained and unconstrained allocation assumptions (as per Eichhorn, Gupta and Stubbs [Eichhorn, D., Gupta, F., & Stubbs, E. (1998). Using constraints to improve the robustness of asset allocation. Journal of Portfolio Management, Spring, 41–48.]), we employ Markowitz portfolio optimization and find widely varying allocation outcomes. However, timberland entered nearly all portfolios, accounting for large percentages in several scenarios, while farmland entered only low‐risk portfolios. At lower risk levels, commercial real estate dominates the real estate allocation but as acceptable risk levels rise, timberland supplants commercial real estate as the primary component of the portfolio's real estate allocation.
Genetic causes and consequences of the breakdown of self-incompatibility: case studies in the Brassicaceae
Authors: MABLE BARBARA K. 
Published: May 2008

SummaryThe genetic consequences of inbreeding is a subject that has received thorough theoretical attention and has been of interest to empirical biologists since the time of Darwin. Particularly for species with genetically controlled mechanisms to promote outcrossing (self-incompatibility or SI systems), it is expected that high levels of genetic load should accumulate through sheltering of deleterious recessive mutations. Nevertheless, transitions to selfing are common across angiosperms, which suggests that the potentially negative consequences of reduced heterozygosity and genetic diversity are balanced by other factors, such as reproductive assurance. This mini-review focuses on empirical research in the Brassicaceae to emphasize some of the genetic consequences of shifts to inbreeding in terms of mechanisms for loss of SI, changes in genetic diversity following loss of SI, and inbreeding depression in relation to outcrossing history. Despite the long history of theoretical attention, there are still some surprisingly large gaps in our understanding in each of these areas. Rather than providing a complete overview, examples are drawn predominantly from published and emerging data fromArabidopsis thalianaand its relatives to highlight recent progress and remaining questions. We are currently on the brink of major breakthroughs in understanding due both to advances in sequencing technology and a shift in focus from crop plants to natural populations, where critical factors such as population structure, phylogeography, demographic history, partial compatibility and individual variation can be taken into account when investigating the nature of the selective forces regulating mating system evolution.
Prior selfing and the selfing syndrome in animals: an experimental approach in the freshwater snailBiomphalaria pfeifferi
Authors: TIAN-BI YVES-NATHAN T. , N'GORAN ELIEZER K. , N'GUETTA SIMON-PIERRE , MATTHYS BARBARA , SANGARE ABDOURAHAMANE , JARNE PHILIPPE 
Published: May 2008

SummaryInbreeding species of hermaphroditic animals practising copulation have been characterized by few copulations, no waiting time (the time that an isolated individual waits for a partner before initiating reproduction compared with paired individuals) and limited inbreeding (self-fertilization) depression. This syndrome, which has never been fully studied before in any species, is analysed here in the highly selfing freshwater snailBiomphalaria pfeifferi. We conducted an experiment under laboratory conditions over two generations (G1and G2) using snails sampled from two populations (100 individuals per population). G1individuals were either isolated or paired once a week (potentially allowing for crosses), and monitored during 29 weeks for growth, fecundity and survival. Very few copulations were observed in paired snails, and there was a positive correlation in copulatory activity (e.g. number of copulations) between the male and female sexual roles. The waiting time was either null or negative, meaning that isolated individuals initiated reproduction before paired ones. G2offspring did not differ in hatching rate and survival (to 28 days) between treatments, but offspring from paired individuals grew faster than those from isolated individuals. On the whole, the self-fertilization depression was extremely low in both populations. Another important result is that paired G1individuals began laying (selfed) eggs several weeks prior to initiating copulation: this is the first characterization of prior selfing (selfing initiated prior to any outcrossing) in a hermaphroditic animal. A significant population effect was observed on most traits studied. Our results are discussed with regard to the maintenance of low outcrossing rates in highly inbreeding species.
Effective population size and tests of neutrality at cytoplasmic genes inArabidopsis
Authors: WRIGHT STEPHEN I. , NANO NARDIN , FOXE JOHN PAUL , DAR VAQAAR-UN NISA 
Published: May 2008

SummaryCytoplasmic genomes typically lack recombination, implying that genetic hitch-hiking could be a predominant force structuring nucleotide polymorphism in the chloroplast and mitochondria. We test this hypothesis by analysing nucleotide polymorphism data at 28 loci across the chloroplast and mitochondria of the outcrossing plantArabidopsis lyrata, and compare patterns with multiple nuclear loci, and the highly selfingArabidopsis thaliana. The maximum likelihood estimate of the ratio of effective population size at cytoplasmic relative to nuclear genes inA. lyratadoes not depart from the neutral expectation of 0·5. Similarly, the ratio of effective size inA. thalianais close to unity, the neutral expectation for a highly selfing species. The results are thus consistent with neutral organelle polymorphism in these species or with comparable effects of hitch-hiking in both cytoplasmic and nuclear genes, in contrast to the results of recent studies on gynodioecious taxa. The four-gamete test and composite likelihood estimation provide evidence for very low levels of recombination in the organelles ofA. lyrata, although permutation tests do not suggest that adjacent polymorphic sites are more closely linked than more distant sites across the two genomes, suggesting that mutation hotspots or very low rates of gene conversion could explain the data.
When gametophytic self-incompatibility meets gynodioecy
Authors: EHLERS BODIL K. , SCHIERUP MIKKEL H. 
Published: May 2008

SummaryThe occurrence of gynodioecy among angiosperms appears to be associated with self-compatibility. We use individual-based simulations to investigate the conditions for breakdown of a gametophytic self-incompatibility system in gynodioecious populations and make a comparison with hermaphroditic populations where the conditions are well known. We study three types of mutations causing self-compatibility. We track the fate of these mutations in both gynodioecious and hermaphroditic populations, where we vary the number of S-alleles, inbreeding depression and selfing rate. We find that the conditions for breakdown are less stringent if the population is gynodioecious and that the breakdown of self-incompatibility tends to promote stability of gynodioecious populations since it results in a higher frequency of females. We also find that fecundity selection has a large effect on the probability of breakdown of self-incompatibility, in particular if caused by a mutation destroying the female function of the S-locus.
Mating system and recombination affect molecular evolution in fourTriticeaespecies
Authors: HAUDRY A. , CENCI A. , GUILHAUMON C. , PAUX E. , POIRIER S. , SANTONI S. , DAVID J. , GLÉMIN S. 
Published: May 2008

SummaryMating systems and recombination are thought to have a deep impact on the organization and evolution of genomes. Because of the decline in effective population size and the interference between linked loci, the efficacy of selection is expected to be reduced in regions with low recombination rates and in the whole genome of self-fertilizing species. At the molecular level, relaxed selection is expected to result in changes in the rate of protein evolution and the pattern of codon bias. It is increasingly recognized that recombination also affects non-selective processes such as the biased gene conversion towards GC alleles (bGC). Like selection, this kind of meiotic drive in favour of GC over AT alleles is expected to be reduced in weakly recombining regions and genomes. Here, we investigated the effect of mating system and recombination on molecular evolution in fourTriticeaespecies: two outcrossers (Secale cerealeandAegilops speltoides) and two selfers (Triticum urartuandTriticum monococcum). We found that GC content, possibly driven by bGC, is affected by mating system and recombination as theoretically predicted. Selection efficacy, however, is only weakly affected by mating system and recombination. We investigated the possible reasons for this discrepancy. A surprising one is that, in outcrossing lineages, selection efficacy could be reduced because of high substitution rates in favour of GC alleles. Outcrossers, but not selfers, would thus suffer from a ‘GC-induced’ genetic load. This result sheds new light on the evolution of mating systems.
The number, age, sharing and relatedness ofS-locus specificities inPrunus
Authors: VIEIRA JORGE , FONSECA NUNO A. , SANTOS RAQUEL A. M. , HABU TSUYOSHI , TAO RYUTARO , VIEIRA CRISTINA P. 
Published: May 2008

SummaryIn gametophytic self-incompatibility systems, many specificities (different ‘lock-and-key’ combinations) are maintained by frequency-dependent selection for very long evolutionary times. In Solanaceae, trans-specific evolution (the observation that an allele from one species may be more closely related to an allele from another species than to others from the same species) has been taken as an argument for the very old age of specificities. In this work, by determining, for the first time, the age of extantPrunusspecies, we show that this reasoning cannot be applied to Prunoideae. Furthermore, since our sample size is large (allS-RNaseencoding the female component andSFBencoding the male component GenBank sequences), we were able to estimate the age of the oldestPrunusspecificities. By doing so, we show that the lower variability levels at thePrunus S-locus, in comparison with Solanaceae, is due to the younger age ofPrunusalleles, and not to a difference in silent mutation rates. We show that the ancestor to extantPrunusspecies harboured at least 102 specificities, in contrast to the maximum of 33 observed in extantPrunusspecies. Since the number of specificities that can be maintained in a population depends on the effective population size, this observation suggests a bottleneck inPrunusevolutionary history. Loss of specificities may have occurred during this event. Using only information on amino acid sites that determine specificity differences, and a simulation approach, we show that a model that assumes closely related specificities are not preferentially lost during evolution, fails to predict the observed degree of specificity relatedness.
A selective sweep in or near theSilene latifoliaX-linked geneSlssX
Authors: FILATOV D. A. 
Published: May 2008

SummaryThe most prominent feature of Y chromosomes is that they do not recombine and are usually genetically degenerate, containing only a few genes. White campionSilene latifoliahas evolved sex chromosomes relatively recently, probably within the last 10–15 million years. Perhaps due to its recent origin, the Y chromosome in this species has not completely degenerated and most isolated X-linked genes have intact Y-linked homologues. A gene encoding a protein with strong homology to spermidine synthases,Slss, is the exception to this rule, as the Y-linked copy of this gene has apparently lost its function. Here I report evidence for a recent selective sweep in the X-linked copy of this gene (SlssX) that could reflect compensatory evolution in an X-linked gene that has lost a functional Y-linked homologue. The spread and fixation of an advantageous mutation inSlssXhas resulted in a dramatic loss of genetic diversity and an excess of high-frequency derived polymorphisms in this gene. As the sweep has not affected the closely linkedDD44Xgene, the selective advantage of the mutation that has driven the sweep in theSlssXgene might have been less than 1%.
The effect of a barrier to gene flow on patterns of geographic variation
Authors: BARTON N. H. 
Published: May 2008

SummaryExplicit formulae are given for the effects of a barrier to gene flow on random fluctuations in allele frequency; these formulae can also be seen as generating functions for the distribution of coalescence times. The formulae are derived using a continuous diffusion approximation, which is accurate over all but very small spatial scales. The continuous approximation is confirmed by comparison with the exact solution to the stepping stone model. In both one and two spatial dimensions, the variance of fluctuations in allele frequencies increases near the barrier; when the barrier is very strong, the variance doubles. However, the effect on fluctuations close to the barrier is much greater when the population is spread over two spatial dimensions than when it occupies a linear, one-dimensional habitat: barriers of strength comparable with the dispersal range (B≈σ) can have an appreciable effect in two dimensions, whereas only barriers with strength comparable with the characteristic scale (B\! \approx\! L \equals \sigma \sol \sqrt {2 \mu}\hskip2) are significant in one dimension (μ is the rate of mutation or long-range dispersal). Thus, in a two-dimensional population, barriers to gene flow can be detected through their effect on the spatial pattern of genetic marker alleles.
Angiostrongylus costaricensis egg antigen for the immunodiagnosis of abdominal angiostrongyliasis
Authors: Mesén-Ramírez P. , Abrahams-Sandí E. , Fernández-Quesada K. , Morera P. 
Published: May 2008

AbstractAngiostrongylus costaricensis is the aetiological agent of human abdominal angiostrongyliasis, a parasitic disease reported from the United States to Argentina, with a widespread occurrence of the nematode throughout Central and South America. This study assesses the performance of A. costaricensis eggs as antigen in an enzyme-linked immunosorbent assay (ELISA), for the determination of parasite-specific IgG1 antibodies. The specificity and the sensitivity of the method were 87% and 90.5%, respectively. Through this test it was possible to demonstrate a sharp and early decline in IgG1 antibody in serum samples taken from patients with histopathological diagnosis of abdominal angiostrongyliasis at different time points after surgical treatment. The present work demonstrated the usefulness of the egg antigen in the development of a specific diagnostic test for abdominal angiostrongylosis.