bluuebunny/crossref_metadata_2025_split huggingface dataset:
Population structure of Litopenaeus schmitti (Decapoda: Penaeidae) from the Brazilian coast identified using six polymorphic microsatellite loci
Authors: Maggioni R. , Rogers A. D. , Maclean N. 
Published: November 2003

AbstractThe population structure of the only Litopenaeus species occurring in Brazilian waters, the white shrimp L. schmitti, was surveyed by screening six microsatellite loci. High diversity (HE = 0.863; average number of alleles per locus = 37.8) was found across eight geographical locations (2°S to 27°S). Estimates of overall FST(0.0060) were low but significantly different from zero (P < 0.05). FST pairwise estimates and amova revealed a significant discontinuity around a major biogeographical boundary, near Cabo Frio, at 23°S. This separation may have been caused either by historical or on‐going hydrogeographical and/or selective factors.
Differential gene expression in two strains of the endoparasitic wasp Venturia canescens identified by cDNA‐amplified fragment length polymorphism analysis
Authors: Reineke A. , Schmidt O. , Zebitz C. P. W. 
Published: November 2003

AbstractIn the endoparasitic wasp Venturia canescens (Hymenoptera: Ichneumonidae) two genetically distinct lines, which differ at the VLP1 gene locus, appear to coexist sympatrically in thelytokous as well as arrhenotokous field and laboratory strains. Both lines display quite distinct morphological, physiological and behavioural variations, such as different oviposition strategies, egg numbers and growth rates during early embryonic development. To examine whether more than one gene is affected in the two lines, we applied cDNA‐amplified fragment length polymorphism analysis to examine patterns of gene expression in ovaries of both wasp lines. We show that a number of ovarian transcripts have an altered expression pattern in either line, which was further confirmed by virtual Northern blot analysis. Sequence analysis of the cDNA‐amplified fragment length polymorphism fragments revealed that some of the respective genes are expected to be involved in regulation of protein degradation during stress responses and in signal perception/transduction. The full‐length sequence of two transcription factors (a homeodomain containing protein and a zinc finger protein) differentially expressed in both lines was obtained by RACE‐polymerase chain reaction and their putative role in regulating key developmental processes during embryogenesis is discussed.
MHC diversity in two Acrocephalus species: the outbred Great reed warbler and the inbred Seychelles warbler
Authors: Richardson DAVID. S. , Westerdahl Helena 
Published: November 2003

AbstractThe Great reed warbler (GRW) and the Seychelles warbler (SW) are congeners with markedly different demographic histories. The GRW is a normal outbred bird species while the SW population remains isolated and inbred after undergoing a severe population bottleneck. We examined variation at Major Histocompatibility Complex (MHC) class I exon 3 using restriction fragment length polymorphism, denaturing gradient gel electrophoresis and DNA sequencing. Although genetic variation was higher in the GRW, considerable variation has been maintained in the SW. The ten exon 3 sequences found in the SW were as diverged from each other as were a random sub‐sample of the 67 sequences from the GRW. There was evidence for balancing selection in both species, and the phylogenetic analysis showing that the exon 3 sequences did not separate according to species, was consistent with transspecies evolution of the MHC.
Collembola as alternative prey sustaining spiders in arable ecosystems: prey detection within predators using molecular markers
Authors: Agustí N. , Shayler S. P. , Harwood J. D. , Vaughan I. P. , Sunderland K. D. , Symondson W. O. C. 
Published: November 2003

AbstractCollembola comprise a major source of alternative prey to linyphiid spiders in arable fields, helping to sustain and retain these predators as aphid control agents within the crop. Polymerase chain reaction primers were developed for the amplification, from spider gut samples, of DNA from three of the most abundant species of Collembola in wheat crops in Europe, namelyIsotoma anglicana,Lepidocyrtus cyaneusandEntomobrya multifasciata. The primers amplified fragments of the mitochondrial cytochrome oxidase subunit I (COI) gene and were designed following alignment of comparable sequences for a range of predator and prey species. Each of the primer pairs proved to be species‐specific to a Collembola species, amplifying DNA fragments from 211 to 276 base pairs in length. Following consumption of a single collembolan, prey DNA was detectable in 100% of spiders after 24 h of digestion. We report the first use of DNA‐based techniques to detect predation by arthropods on natural populations of prey in the field. All three species of Collembola were consumed by the spiders. By comparing the ratios of the Collembola species in the field with the numbers of spiders that gave positive results for each of those species, it was possible to demonstrate that the spiders were exercising prey choice. Overall, a single target species of Collembola was eaten by 48% of spiders while a further 16% of spiders contained DNA from two different species of Collembola. Preference was particularly evident forI. anglicana, the species most frequently found in spider guts yet the least numerous of the three target species in the field.
Predicting yield loss due to interference from two weed species using early observations of relative weed leaf area
Authors: VAN ACKER R. C. , LUTMAN P. J. W. , FROUD‐WILLIAMS R. J. 
Published: November 2003

SummaryExperiments were conducted on linseed (Linum usiãissimumL.) and autumn‐sown field bean (Vicia fahaL.) to test how well the relative leaf area‐based yield loss prediction model of Kropff & Spitters could estimate yield loss due to interference fromStellaria mediaL. (common chick‐weed) or barley (Hordeum vulgareL.) alone or a combination of bothS. media and barley. Damage coefficients were calculated for all comparisons. Generally, the model provided a better estimate of yield loss due to interference from barley than fromS. mediabecause of both the variability in crop yield response stemming fromS. media'splasticity and the generally minor crop yield response toS. mediainterference. The addition to the model of a parameter accounting for asymptotic yield loss was, generally, not warranted for eitherS. mediaor barley in the single‐weed species data sets. When bothS. mediaand barley were present as weed species in the crop, the model that fitted the data best for six out of 10 data sets was the one in which a separate damage coefficient was included for both species. There was no evidence that the presence ofS. mediainfluenced damage coefficient values for barley. However, in the presence of barley a parameter accounting for asymptotic yield loss was warranted forS. mediain the two‐weed species model. The combination of the addition of this parameter and the presence or barley affected the values of the damage coefficients forS. mediain the two‐weed species compared with the single‐weed species models. Consequently, it was shown for these two weed species that two‐weed species yield loss prediction models parameterized using data from single‐weed species experiments generally resulted in different estimates of yield loss in comparison with models parameterized using data from two‐weed species experiments.
Effects of isoproturon on photosynthesis in susceptible and resistant biotypes of Phalaris minor and wheat
Authors: SINGH S. , KIRKWOOD R. C. , MARSHALL G. 
Published: November 2003

SummaryWheat (cv. WH‐147) and five biotypes of Phalaris minor Retz. (KR‐1, H‐4, K‐2, H‐2 and J‐1) were treated with isoproturon in controlled environmental conditions to assess their level of resistance. Resistance of P. minor to isoproturon was found in the order of KR‐1 > H‐4 > K‐2 > H‐2 = J‐1. Compared with the susceptible (S) biotype (H‐2), the resistant (R) biotypes (KR‐1. H‐4 and K‐2) of P. minor required 13.0, 4.5 and 2.7 times higher doses of isoproturon for a 50% reduction in growth (GR50) and 2.4 times that of the S biotype (H‐2) by wheat. The corresponding figures for KR‐1, H‐4, K‐2 biotypes and wheat were 18, 4.1, 2.4 and 4.6 times based on dry weight reduction. The effect of isoproturon on photosynthesis was studied in vitro using five biotypes of P. minor and in viro with wheat. KR‐1 (R) and H‐2 (S) biotypes of P. minor. Under in vitro treatment conditions isoproturon inhibited the photosynthesis of all five P. minor biotypes, whereas in vivo the recovery was greater in the R biotype than in the wheat and the S biotype. Effects on chlorophyll fluorescence were also measured in wheat and the KR‐1 (R) and H‐2 (S) biotypes of P. minor. A 4‐h treatment of excised leaves incubaled in isoproluron solution (0.025 and 0.05 mm concentration) resulted in a decreased fluorescence coefficient (Fv Fm ratio in which Fv= variable fluorescence (Fm ‐ Fo): Fm= the maximum fluorescence and Fo= initial fiuorescence) in wheat (Triticum aestivum L.) and both biotypes of P. Minor. The recovery was, however, greater in the R biotype than in wheat and it was completely recovered within 24 h. No recovery was recorded in the case of the S biotype of P. minor and a greater recovery time was required for wheat than the R biotype. The higher dose required for growth inhibition in the R biotype and rapid recovery of oxygen evolution and fluorescence coeflicient under in viro conditions together with the absence of selectivity in vitro suggests that the target site was unaffected. It can be conjectured that resistance to isoproturon is most probably because of enhanced metabolism or sequestration of isoproturon, resulting in decreased target site delivery.
Modelling crop:weed interactions in wheat with ALMANAC
Authors: DEBAEKE P. , CAUSSANEL J. P. , KINIRY J. R. , KAFIZ B. , MONDRAGON G. 
Published: November 2003

SummaryALMANAC is a dynamic model for plant growth, water balance and soil nitrogen dynamics that can simulate on a daily basis two or more competing species. The simulation of competition for light is based on Beer's law, allowing a different extinction coefficient (k) for each species. Light is partitioned between species based on k‐values, leaf area index and plant heights. Total hiomass is simulated with radiation use efficiency and grain yield with a harvest index approach, sensitive to water stress. The model simulates competition for water and nutrients based on each species current rooting zone and demand by each species. The effect of crop management on the competition issue can he simulated. The model was evaluated in Dijon (France) using 4 years of experimental data on wheat:oat mixtures, differing in oat (Avena sativa L.) densities, the period of oat emergence, the date of weed suppression by herbicides and the wheat (Triticun aestivum L.) genotype. Additional data on oilseed rape (Brassica nupus L.) and vetch (Vilcia sauiva L.) competition in spring wheat were also used. The wheat grain yield was reasonably simulated with a root mean square error (RMSE) of 0.10‐0.35 t ha‐1. Corresponding values for oats were 0.10‐0.55 t ha‐1. The competitiveness of oats, oilseed rape and vetch was correctly simulated. The model appears as a reasonable tool for estimating damage thresholds in integrated weed control programmes.
Evaluation of a new combined SpO2/PtcCO2 sensor in anaesthetized paediatric patients
Authors: Dullenkopf Alexander , Bernardo Stefano Di , Berger Felix , Fasnacht Margrit , Gerber Andreas C. , Weiss Markus 
Published: November 2003

SummaryBackground The recently introduced TOSCA monitor (Linde Medical Sensors AG, Basel, Switzerland) combines pulse oximetry (SpO2) and transcutaneous PCO2 (PtcCO2) monitoring in a single ear sensor. The aim of the present study was to evaluate accuracy of the TOSCA monitor to estimate SaO2 and PaCO2 in anaesthetized children.Methods With approval of the hospital ethical committee and after obtaining informed parental consent, the TOSCA sensor was attached to one ear lobe of anaesthetized children in whom arterial access was established for cardiac catheterization or invasive blood pressure monitoring. SpO and PtcCO2 as well as SpO and PECO2 values from the anaesthesia monitoring (AS5; Datex‐Ohmeda, Helsinki, Finland) were compared with SaO2 and PaCO2 values from arterial blood gas analysis. Corresponding data were compared using Bland Altman bias analysis.Results A total of 111 blood samples were taken from 60 children (median age: 4.41 years; 0.35–16.13 years). SaO2 values ranged from 63 to 100% (median: 98.7%), PaCO2 ranged from 3.8 to 7.3 kPa (median: 4.6 kPa). Mean difference (±2 sd) between PaCO2 and PtcCO2 was –0.035 kPa (±0.74 kPa), between PaCO2 and PECO2 0.002 kPa (0.73 kPa), respectively (1 kPa = 7.3 mmHg). Bias and precision between SaO2 and SpO was –0.63% (±2.77%) and 0.13% (±4.52%) between SaO2 and SpO.Conclusions In anaesthetized children, the TOSCA ear sensor allows estimation of SaO2 and PaCO2, comparable in accuracy to endtidal capnometry and finger pulse oximetry. This makes the TOSCA monitor a helpful add‐on to respiratory monitoring in anaesthetized children, in situations, in which endtidal capnometry is unreliable or difficult to establish.
WTO Exceptions as Insurance
Authors: Fischer Ronald D. , Prusa Thomas J. 
Published: November 2003

AbstractThe paper formalizes the notion that GATT exceptions such as antidumping and escape clause actions can act as insurance for import competing sectors affected by adverse price shocks. The authors use a general‐equilibrium model with several import competing sectors and assume incomplete markets so that agents cannot contract insurance. It is shown that sector‐specific contingent protection measures are superior to uniform contingent tariffs as an insurance mechanism. A tax‐cum‐subsidy policy (i.e., taxing all sectors in order to subsidize the shocked sector) also improves welfare and is superior to contingent protection.
A Theory of International Strategic Alliance
Authors: Chen Zhiqi 
Published: November 2003

AbstractAs an alternative to exporting, a firm can enter a foreign market by forging a strategic alliance with its foreign counterpart. The alliance eliminates transportation costs and duplications in product distribution networks. At the same time, strategic alliance lessens competition between the firms so that it leads to smaller outputs and higher prices. The degree of lessening of competition depends on the firms’ ability to commit to output levels. In the case where the firms can credibly commit to output levels, the alliance effectively becomes a cartel, restoring prices to the monopoly level. On the other hand, if such commitment is not credible or not possible, prices will be lower than the monopoly level but will still be higher than that if firms had exported to each other's market directly. The welfare effects of the strategic alliance are in general ambiguous.
Devaluations and Consumption Smoothing
Authors: Bergin Paul R. 
Published: November 2003

AbstractThe paper considers the effect of a nominal exchange rate devaluation on the current account, using an intertemporal model that highlights the interaction between leisure and consumption. An analytical solution demonstrates that household behavior may differ markedly from the simple consumption smoothing emphasized in most previous literature. This distinction has special significance for demand shocks, in which output rises through a rise in labor input and hence a fall in leisure. In particular, consumption tends to move closely with increased output in this context, so a devaluation tends not to improve the current account. This result may cast doubt on the effectiveness of competitive devaluations.
Conditions for Factor Price Equalization in the Integrated World Economy Model
Authors: Qi Ling 
Published: November 2003

AbstractThe lens condition proposed by Deardorff in 1994 has been argued not to be sufficient for factor price equalization in general. This paper shows that the lens condition is necessary and sufficient both in the two‐factor case and in the three‐good case. The results imply that two is the largest number of factors for the lens condition to guarantee factor price equalization when the number of goods and that of countries are arbitrary. A sufficient condition for factor price equalization is also given in the case where the number of goods, that of countries, and that of factors are all arbitrary.
Oxygen accelerates the accumulation of mutations during the senescence and immortalization of murine cells in culture
Authors: Busuttil Rita A. , Rubio Miguel , Dollé Martijn E. T. , Campisi Judith , Vijg Jan 
Published: November 2003

SummaryOxidative damage is a causal factor in aging and cancer, but it is still not clear how DNA damage, the cellular responses to such damage and its conversion to mutations by misrepair or misreplication contribute to these processes. Using transgenic mice carrying a lacZ mutation reporter, we have previously shown that mutations increase with age in most organs and tissues in vivo. It has also been previously shown that mouse cells respond to oxidative stress, typical of standard culture conditions, by undergoing cellular senescence. To understand better the consequences of oxidative stress, we cultured mouse embryo fibroblasts (MEFs) from lacZ mice under physiological oxygen tension (3%) or the high oxygen tension (20%) associated with standard culture, and determined the frequency and spectrum of mutations. Upon primary culture, the mutation frequency was found to increase approximately three‐fold relative to the embryo. The majority of mutations were genome rearrangements. Subsequent culture in 20% oxygen resulted in senescence, followed by spontaneous immortalization. Immortalization was accompanied by an additional three‐fold increase in mutations, most of which were G:C to T:A transversions, a signature mutation of oxidative DNA damage. In 3% oxygen, by contrast, MEFs did not senesce and the mutation frequency and spectrum remained similar to primary cultures. These findings demonstrate for the first time the impact of oxidative stress on the genomic integrity of murine cells during senescence and immortalization.
RENAL RESEARCH INSTITUTE SYMPOSIUM: A System of Quality Management in Dialysis
Authors: Van Der Sande Frank M. , Kooman Jeroen P. , Ikenroth Laurie J. , Gommers Evelien P. , Leunissen Karel M. L. 
Published: November 2003

AbstractBecause of changes in legislation, dialysis may now be performed in all hospitals in The Netherlands, which could affect the quality of the therapy. Therefore a system of quality management in health care, and especially in dialysis, was developed. In this article the implementation and evaluation of such a system is described.
RENAL RESEARCH INSTITUTE SYMPOSIUM: Effective Diffusion Volume Flow Rates (Qe) for Urea, Creatinine, and Inorganic Phosphorous (Qeu, Qecr, QeiP) During Hemodialysis
Authors: Gotch Frank A. , Panlilio Froilan , Sergeyeva Olga , Rosales Laura , Folden Tom , Kaysen George , Levin Nathan 
Published: November 2003

AbstractIn vivo solute clearances can be estimated from dialyzer blood (Qb) and dialysate (Qd) flow rates and a solute‐ and dialyzer‐specific overall permeability membrane area product (KoA). However, these calculations require knowledge of the flow rate of the effective solute distribution volume in the flowing bloodstream (Qe) in order to calculate in vivo clearances and KoAs. We have determined Qe for urea, creatinine, and inorganic phosphorus from changes in concentrations across the blood compartment and mass balance between the blood and dialysate streams. We made four serial measurements over one dialysis in 23 patients and found that Qeu equals the total blood water flow rate, Qecr equals the plasma water flow rate plus 61% of red cell water flow rate, and QeiP is limited to the plasma water flow rate. Equations are derived to calculate Qe for each of these solutes from Qb and hematocrit and in vivo KoAs for each solute were calculated.
RENAL RESEARCH INSTITUTE SYMPOSIUM: Temperature Control by the Blood Temperature Monitor
Authors: Schneditz Daniel , Ronco Claudio , Levin Nathan 
Published: November 2003

AbstractThe rationale of temperature control during hemodialysis (HD) is to prevent heat accumulation, which increases body temperature and enhances hypotensive susceptibility. Treatments where thermal energy is neither delivered nor removed from the patient through the extracorporeal circulation (so‐called extracorporeal thermoneutral treatments) lead to a marked increase in body temperature and to considerable heat accumulation during HD. Since this accumulation of heat cannot be explained by increased heat production, it must be related to reduced heat dissipation through the body surface. Peripheral vasoconstriction, and cutaneous vasoconstriction in particular, compensating for the ultrafiltration‐induced decrease in blood volume is considered an important component in this setting. Therefore, to maintain temperature homeostasis, thermal energy has to be cleared from the patient by the extracorporeal system because cutaneous clearance of thermal energy is compromised intradialytically. The focus on dialysate temperature alone does not properly address the problem of controlled extracorporeal heat removal because dialysate temperature is only one of the variables involved in that process. These difficulties can be addressed by changing from the control of dialysate temperature to control of body temperature. Control of body temperature and temperature homeostasis is achievable by the physiologic feedback control system realized in the temperature control mode (T‐mode) of the blood temperature monitor (BTM). The delivery of isothermic dialysis, that is, dialysis where body temperature is controlled to remain constant during the treatment, has impressively improved hemodynamic stability in hypotension prone patients.
Modulatory Effect of Cyclooxygenase Inhibitors on Sildenafil-Induced Antinociception
Authors: Patil Chandrashekhar S. , Jain Naveen K. , Singh Amarjit , Kulkarni Shrinivas K. 
Published: November 2003

Peripheral activation of the NO-cGMP pathway has been implicated in various nociceptive conditions. The antinociceptive effect of the PDE-5 inhibitor, sildenafil, alone or in combination with cyclooxygenase inhibitor diclofenac and nimesulide, was assessed in the different animal models of peripheral nociception. In the present study we investigated the possible interaction between cyclooxygenase and NO-cGMP pathway in writhing assay and carrageenan-induced hyperalgesia in mice and rats, respectively. Sildenafil [1–2 mg/kg, i.p. or 50–100 µg/paw, intraplantar (i.pl.)], nimesulide (1–2 mg/kg, i.p. or 25–50 µg/paw, i.pl.) and diclofenac (1–2 mg/kg, i.p. or 25–50 µg/paw, i.pl.) exhibited an antinociceptive effect in both the models. When ineffective doses of sildenafil (0.5 mg/kg, i.p and 25 µg/paw, i.pl.) were co-administered with ineffective doses of nimesulide (0.5 mg/kg, i.p. and 10 µg/paw, i.pl.) and diclofenac (0.5 mg/kg, i.p. and 10 µg/paw, i.pl.), there was a significant increase in the antinociceptive effect in both the models of peripheral nociception. Further, the potentiation of the effect was blocked by <i>L</i>-NAME (20 mg/kg, i.p., 100 µg/paw, i.pl.), a non-selective NOS inhibitor and methylene blue (1 mg/kg, i.p.), a guanylate cyclase inhibitor. <i>L</i>-NAME or methylene blue itself had little or no effect on both the models of hyperalgesia. These results suggest that cyclooxygenase, NO and cGMP are relevant in the combination-induced antinociception. In conclusion, sildenafil induced antinociception, and its potentiation of the effect of the cyclooxygenase inhibitors nimesulide and diclofenac was probably mediated through the activation of the NO-cGMP pathway and inhibition of cyclic GMP degradation.