bluuebunny/crossref_metadata_2025 huggingface dataset:
Familial Aggregation and Heritability of Electrocardiographic Intervals and Heart Rate in a Rural Chinese Population
Authors: Li Jianping , Huo Yong , Zhang Yan , Fang Zhian , Yang Jianhua , Zang Tonghua , Xu Xiping , Xu Xin
Published: April 2009

Background: Estimates of the genetic influences on electrocardiographic (ECG) parameters are inconsistent in previous reports, and no such studies have been performed in China. So we estimated genetic contributions to PR and QRS intervals and the rate‐adjusted QT interval (Bazett's QTc) in a Chinese rural population.

Methods: A total of 2909 subjects from 847 families were enrolled in the current study. Genetic contributions to ECG parameters were estimated in two ways: correlation coefficients among family members (father‐mother, parent‐offspring, first sibling‐other sibling) and the heritability of each of the ECG parameters.

Results: Our results showed significant correlations among family members on theses parameters: the correlation coefficients for PR interval, QRS duration, QTc interval, and HR, between parent‐sibling, and sibling‐sibling were 0.17 and 0.13, 0.18 and 0.23, 0.22 and 0.28, 0.19 and 0.18, respectively. The heritability for PR interval, QRS duration, QTc interval, and HR were estimated as 0.34, 0.43, 0.40, and 0.34, respectively.

Conclusion: Genetic factors, together with the environmental and other cofactors contribute no more than 60% to the variance of the ECG intervals, supporting the concept that multiple factors, including gene‐gene and gene‐environment interactions could influence ECG interval phenotypes, and genetic factors play a major role.
Correlation of Electrical and Mechanical Reverse Remodeling after Cardiac Resynchronization Therapy
Authors: Kamireddy Swapna , Agarwal Sunil Kumar , Adelstein Evan , Jain Sandeep , Saba Samir
Published: April 2009

Background: Cardiac resynchronization therapy (CRT) improves clinical outcome in many patients with refractory heart failure (HF). This study examined whether CRT is associated with reverse electrical remodeling by surface electrocardiogram (ECG).

Methods: Consecutive CRT recipients at the University of Pittsburgh Medical Center with >90 days of follow‐up were included in this analysis. ECG data were abstracted from medical records. Subjects with a relative increase of ≥15% in left ventricular ejection fraction (LVEF) after CRT were considered responders.

Results: A total of 113 patients (age 69 ± 11 years, men 70%, white 92%) were followed for a mean duration of 407 ± 290 (92–1439) days. Overall, LVEF increased after CRT (29 ± 13% vs 24 ± 9%; P < 0.01) and 50% of patients were responders. The mean native QRS interval among responders was higher than in nonresponders (163 ± 32 ms vs 148 ± 29 ms; P < 0.01). More than 3 months after CRT, there was no change in the paced QRS duration compared to baseline. Paced QRS duration, however, decreased among responders and increased among nonresponders and was significantly different by response status (P < 0.001). There was a significant correlation between increase in LVEF and decrease in paced QRS width in the overall population (r =−0.3; P < 0.01).

Conclusions: Among responders to CRT, the paced QRS width decreases significantly, whereas it increases among nonresponders. Given the paced nature of the QRS, the improved conduction probably reflects enhanced cell‐to‐cell coupling after CRT as opposed to improved conduction within the His‐Purkinje system. These findings have significant implications as to the mechanisms of benefit from CRT.
ST Segment “Hump” during Exercise Testing and the Risk of Sudden Cardiac Death in Patients with Hypertrophic Cardiomyopathy
Authors: Michaelides Andreas P. , Stamatopoulos Ilias , Antoniades Charalambos , Anastasakis Aris , Kotsiopoulou Christina , Theopistou Artemisia , Misailidou Maria , Fourlas Christos , Elliott Perry M. , Stefanadis Christodoulos
Published: April 2009

Background:The appearance of a discrete upward deflection of the ST segment termed “the ST hump sign” (STHS) during exercise testing has been associated with resting hypertension and exaggerated blood pressure response to exercise.

Objective:We investigated the prevalence and clinical significance of this sign in a population of patients with hypertrophic cardiomyopathy.

Methods:Eighty‐one patients with hypertrophic cardiomyopathy (HCM) who underwent cardiopulmonary exercise testing were followed in a retrospective cohort study for a mean period of 5.3 years.

Results:The appearance of the STHS at the peak of exercise testing was observed in 42 patients (52%), particularly in the inferior and the lateral leads. Patients with the STHS had higher fractional shortening and maximum left ventricular wall thickness and exhibited more frequently outflow tract gradient >30 mmHg at rest. Furthermore, the presence of STHS was a strong independent predictor of the risk of sudden cardiac death (SCD), as the latter occurred in eight of the patients with this sign (8/42, 19%) and in none of the patients without it (0/39, 0%) (P < 0.001).

Conclusion:The appearance of a “hump” at the ST segment during exercise testing appears to be a risk factor for SCD in patients with HCM. However, further studies are necessary to validate this finding in larger populations and to elucidate the mechanism of the appearance of the “hump.”
Nighttime Vagal Cardiac Control and Plasma Fibrinogen Levels in a Population of Working Men and Women
Authors: Von Känel Roland , Thayer Julian F. , Fischer Joachim E.
Published: April 2009

Background: Elevated plasma fibrinogen levels have prospectively been associated with an increased risk of coronary artery disease in different populations. Plasma fibrinogen is a measure of systemic inflammation crucially involved in atherosclerosis. The vagus nerve curtails inflammation via a cholinergic antiinflammatory pathway. We hypothesized that lower vagal control of the heart relates to higher plasma fibrinogen levels.

Methods: Study participants were 559 employees (age 17–63 years; 89% men) of an airplane manufacturing plant in southern Germany. All subjects underwent medical examination, blood sampling, and 24‐hour ambulatory heart rate recording while kept on their work routine. The root mean square of successive differences in RR intervals during the night period (nighttime RMSSD) was computed as the heart rate variability index of vagal function.

Results: After controlling for demographic, lifestyle, and medical factors, nighttime RMSSD explained 1.7% (P = 0.001), 0.8% (P = 0.033), and 7.8% (P = 0.007), respectively, of the variance in fibrinogen levels in all subjects, men, and women. Nighttime RMSSD and fibrinogen levels were stronger correlated in women than in men. In all workers, men, and women, respectively, there was a mean ± SEM increase of 0.41 ± 0.13 mg/dL, 0.28 ± 0.13 mg/dL, and 1.16 ± 0.41 mg/dL fibrinogen for each millisecond decrease in nighttime RMSSD.

Conclusions: Reduced vagal outflow to the heart correlated with elevated plasma fibrinogen levels independent of the established cardiovascular risk factors. This relationship seemed comparably stronger in women than men. Such an autonomic mechanism might contribute to the atherosclerotic process and its thrombotic complications.
Managing economic risk in value‐based marketing of fed cattle
Authors: Harri Ardian , Riley John Michael , Anderson John D. , Coble Keith H.
Published: April 2009

This research investigates optimal price risk management strategies for fed cattle producers engaged in grid pricing. Stochastic simulation is used to determine optimal hedge ratios for fed cattle priced on a live weight basis or on a series of grids that vary in terms of premium/discount structure as well as base price. Results indicate that the optimal hedging strategy is greatly affected by the base price used in a particular grid. This has significant implications for pricing efficiency in the cattle market. Base prices that are linked more closely with downstream markets offer the potential to improve pricing efficiency; however, the risk associated with these prices is difficult to manage effectively with existing futures instruments.
Modeling preference heterogeneity in stated choice data: an analysis for public goods generated by agriculture
Authors: Colombo Sergio , Hanley Nick , Louviere Jordan
Published: April 2009

Stated choice models based on the random utility framework are becoming increasingly popular in the applied economics literature. The need to account for respondents’ preference heterogeneity in such models has motivated researchers in agricultural, environmental, health, and transport economics to apply random parameter logit and latent class models. In most of the published literature these models incorporate heterogeneity in preferences through the systematic component of utility. An alternative approach is to investigate heterogeneity through the random component of utility, and covariance heterogeneity models are one means of doing this. In this article we compare these alternative ways of incorporating preference heterogeneity in stated choice models and evaluate the sensitivity of estimated welfare measures to which approach is selected. We find that a latent class approach fits our data best, but all the models perform well in terms of out‐of‐sample predictions. Finally, we discuss what criteria a researcher can use to decide which approach is most appropriate for a given data set.
Spatial integration at multiple scales: rice markets in Madagascar
Authors: Moser Christine , Barrett Christopher , Minten Bart
Published: April 2009

The dramatic increase in the price of rice and other commodities over the past year has generated new interest in how these markets work and how they can be improved. This article uses an exceptionally rich data set to test the extent to which markets in Madagascar are integrated across space at different scales of analysis and to explain some of the factors that limit spatial arbitrage and price equalization within a single country. We use rice price data across four quarters of 2000–2001 along with data on transportation costs and infrastructure availability for nearly 1,400 communes in Madagascar to examine the extent of market integration at three different spatial scales—subregional, regional, and national—and to determine whether non‐integration is due to high transfer costs or lack of competition. The results indicate that markets are fairly well integrated at the subregional level and that factors such as high crime rates, remoteness, and lack of information are among the factors limiting competition.
District‐level total factor productivity in agriculture: Western Cape Province, South Africa, 1952–2002
Authors: Conradie Beatrice , Piesse Jenifer , Thirtle Colin
Published: April 2009

This article measures total factor productivity (TFP) growth in Western Cape agriculture for 31 magisterial districts from 1952 to 2002 to illustrate the benefits of disaggregation compared with national TFPs. There is negative or low growth in the eastern districts and rapid growth in the western districts. The regions with substantial chicken, pigs, dairy, and, especially, export fruit production grew rapidly, whereas the sheep‐dominated Karoo had negative growth. Productivity growth correlates mostly with output mix, which in turn depends on irrigation investment. A similar program will be needed at the national level if prosperity is to be extended to black smallholders who currently lack access to water and other modern infrastructure.
The impact of water conservation and intensification technologies: empirical evidence for rice farmers in Ghana
Authors: Faltermeier Liane , Abdulai Awudu
Published: April 2009

This study employs the propensity score matching model to examine the impact of the adoption of water conservation and intensification technologies on farm output and income among small‐scale lowland rice farmers in the Northern Region of Ghana. The matching was conducted based on the Mahalanobis distance combined with the propensity score. Balancing tests by checking the mean standardized absolute bias in the matched sample were conducted as well as a sensitivity analysis was conducted to check for hidden bias due to unobservable selection. The empirical results show a positive and significant impact of the adoption of bunds technology on input demand as well as a positive but insignificant impact on output supply and net returns. Adopters of the dibbling technology were found to have higher output supply, whereas no statistically significant difference was found between the incomes of adopters and nonadopters of dibbling seed method. The results, however, reveal a positive and significant effect on output and net returns when the dibbling method is combined with intensified weeding. The estimates were found to be relatively insensitive to hidden bias.
Factors influencing the profitability of fertilizer use on maize in Zambia
Authors: Xu Zhiying , Guan Zhengfei , Jayne T.S. , Black Roy
Published: April 2009

Fertilizer use remains very low in most of Africa despite widespread agreement that much higher use rates are required for sustained agricultural productivity growth. This study uses longitudinal farm survey data to estimate maize yield response functions in a relatively high‐potential zone of Zambia to determine the profitability of fertilizer use under a range of small‐farm conditions found within this zone. The theoretical framework used in this study incorporates agronomic principles of the crop growth process. We generalize the asymmetric production models and define a concept of yield scaling factors. The model distinguishes different roles of inputs and non‐input factors in crop production. We estimate the effects of conventional production inputs as well as of household characteristics and government programs on maize yield. The results indicate that recommended fertilizer application rates in the two specific years were often unprofitable, given observed price conditions and the yield response to fertilizer. However, there was substantial variability in yield response to fertilizer based upon the rate of application, the timeliness of fertilizer availability, the use of animal draught power during land preparation, and whether the household incurred the death of an adult member in the past three years. These modifying factors, as well as variations in input and output prices due to proximity to roads and markets, substantially affected the profitability of fertilizer use on maize.
Breeding latitude and timing of spring migration in songbirds crossing the Gulf of Mexico
Authors: Langin Kathryn M. , Marra Peter P. , Németh Zoltán , Moore Frank R. , Kurt Kyser T. , Ratcliffe Laurene M.
Published: April 2009

Each spring, millions of songbirds migrate across the Gulf of Mexico on their way to breeding sites in North America. Data from radar and migration monitoring stations have revealed broad patterns in the spatial and temporal course of trans‐Gulf migration. Unfortunately, we have limited information on where these birds have previously spent the winter and where they are migrating to breed. Here we measure stable‐hydrogen isotopes in feathers (δDf) to infer the breeding latitude of five species of songbirds – hooded warblers Wilsonia citrina, American redstarts Setophaga ruticilla, black‐and‐white warblers Mniotilta varia, ovenbirds Seiurus aurocapilla, and northern waterthrushes S. noveboracensis– that were captured at a stopover site along the coast of southwestern Louisiana in spring 2004. Values of δDf across all species ranged from −163 to −35‰ (n=212), and within most species the range was consistent with the latitudinal extent of known breeding sites in central and eastern North America. Individuals that arrived first along the northern Gulf coast had δDf values indicative of southerly breeding sites in hooded warblers, American redstarts, black‐and‐white warblers, and ovenbirds, but no relationship was found between passage timing and δDf for northern waterthrushes. Our findings suggest that spring passage is often timed to coincide with the emergence of suitable conditions on breeding areas, with southern breeding birds migrating first.
Glucose infusions into peripheral veins in the management of neonatal hypoglycemia – 20% instead of 15%?
Authors: Vanhatalo T , Tammela O
Published: April 2009

Aim: To establish whether peripheral intravenous 20% glucose solutions would cause less local irritation, fewer cannulation changes and less weight gain than 15% glucose in newborn infants.

Methods: A total of 121 newborn infants with hypoglycemia were randomized to receive either 20% (group 20%, 60 infants) or 15% (group 15%, 61 infants) glucose infusions, which were initiated at 8 mg/kg/min rates and tapered according to the blood glucose levels. When the cannulation site had to be changed, signs of phlebitis at the previous cannulation site were scored (0–3). Number of cannulation site changes, durations of infusions and the infants’ daily weights were recorded.

Results: The median durations of infusions in groups 20 and 15% were 4 (range 2–7) days versus 4 (range 2–8) days and the median number of cannulation site changes were 1 (range 0–6) versus 1 (range 0–5), respectively. Thirty‐six infants in group 20% and 37 in group 15% developed some phlebitis, median severity scores being 1 (range 0–7) versus 15% 1 (range 0–8). The weights during the treatment were also similar.

Conclusion:  20% and 15% glucose solutions can be infused equally safely into peripheral veins in neonates.
A comparative study of sanitary napkins and absorbent nappy pads for urine output measurement in neonates
Authors: Dutta Sourabh , Saini Shiv Sajan , Narang Anil
Published: April 2009

Aim: To compare sanitary napkins and absorbent nappy pads (ANP) for urine output (UO) measurement.

Methods: Phase 1: Freshly passed neonatal urine (5, 10 and 15 mL) was poured onto preweighed sanitary napkins or ANP, which were juxtaposed to the genital area of manikins placed in incubators/warmers and weighed at ½, 1, 2, 4, 5 and 6 hr. Outcome was percentage weight change from baseline. Phase 2: Five very low birth weight boys in incubators had UO measurement by test tubes. A sanitary napkin or ANP was co‐applied with the test tube for 4 h each. Urine collected in the test tube was measured and poured on the device, which was reapplied. Weight and wetness were checked.

Results: Phase 1: Mean urine loss was 8.35, 13.8, 20.1, 25.2, 33.1, 38.7 and 42.6% at ½, 1, 2, 3, 4, 5 and 6 h, respectively (repeated measures ANOVA [RM‐ANOVA], p < 0.001). Loss was higher with ANP than sanitary napkins (32.1% vs. 13.4%, two‐way RM‐ANOVA, p = 0.001). There was less loss in incubators versus radiant warmers at 6 h (p = 0.09). Phase 2: There was 12.1 and 26% deficit with sanitary napkin and ANP, respectively. Wetness was felt in one and four cases, respectively.

Conclusion: Urinary losses are less from sanitary napkins than ANPs.
Labour increases the surface expression of two toll‐like receptors in the cord blood monocytes of healthy term newborns
Authors: Shen Chung‐Min , Lin Shih‐Chang , Niu Dau‐Ming , Kou Yu Ru
Published: April 2009

Aim: Mode of delivery may influence the innate immune system in newborns. We investigated the effect of maternal labour on the expression of two toll‐like receptors, TLR2 and TLR4, in monocytes obtained from healthy full‐term newborns.

Methods: Monocytes were obtained from cord blood of 48 newborns that have been vaginally delivered (VD) and 14 newborns delivered by elective caesarean section (CS) without labour. Peripheral blood was also obtained from 17 healthy adults. Surface expression of TLR2 and TLR4 in the monocytes was measured by antihuman TLR2 or TLR4 monoclonal antibody and immunofluorescence flow cytometry. TLR2 and TLR4 mRNA levels were evaluated by real‐time PCR.

Results: CS newborns had a significantly lower level of TLR2 and TLR4 surface expression on monocytes than VD newborns. No significant difference was found between the surface expression of VD newborns and healthy adults. TLR2 and TLR4 mRNA levels in monocytes did not vary among the three study groups.

Conclusion: Labour may up‐regulate TLR2 and TLR4 on the cord blood monocytes of newborns at the protein level. Since TLRs are an important part of the innate immune system, our findings suggest that labour may be immunologically beneficial to normal newborns.
ThermoFAD, a Thermofluor®‐adapted flavin ad hoc detection system for protein folding and ligand binding
Authors: Forneris Federico , Orru Roberto , Bonivento Daniele , Chiarelli Laurent R. , Mattevi Andrea
Published: April 2009

In living organisms, genes encoding proteins that contain flavins as a prosthetic group constitute approximately 2–3% of the total. The fluorescence of flavin cofactors in these proteins is a property that is widely employed for biochemical characterisation. Here, we present a modified Thermofluor® approach called ThermoFAD (Thermofluor®‐adapted flavin ad hoc detection system), which simplifies identification of optimal purification and storage conditions as well as high‐affinity ligands. In this technique, the flavin cofactor is used as an intrinsic probe to monitor protein folding and stability, taking advantage of the different fluorescent properties of flavin‐containing proteins between the folded and denatured state. The main advantage of the method is that it allows a large amount of biochemical data to be obtained using very small amounts of protein sample and standard laboratory equipment. We have explored several cases that demonstrate the reliability and versatility of this technique when applied to globular flavoenzymes, membrane‐anchored flavoproteins, and macromolecular complexes. The information gathered from ThermoFAD analysis can be very valuable for any biochemical and biophysical analysis, including crystallisation. The method is likely to be applicable to other classes of proteins that possess endogenous fluorescent cofactors and prosthetic groups.
Hyperefficient PrPSc amplification of mouse‐adapted BSE and scrapie strain by protein misfolding cyclic amplification technique
Authors: Fujihara Aiko , Atarashi Ryuichiro , Fuse Takayuki , Ubagai Kaori , Nakagaki Takehiro , Yamaguchi Naohiro , Ishibashi Daisuke , Katamine Shigeru , Nishida Noriyuki
Published: April 2009

Abnormal forms of prion protein (PrPSc) accumulate via structural conversion of normal PrP (PrPC) in the progression of transmissible spongiform encephalopathy. Under cell‐free conditions, the process can be efficiently replicated using in vitro PrPSc amplification methods, including protein misfolding cyclic amplification. These methods enable ultrasensitive detection of PrPSc; however, there remain difficulties in utilizing them in practice. For example, to date, several rounds of protein misfolding cyclic amplification have been necessary to reach maximal sensitivity, which not only take several weeks, but also result in an increased risk of contamination. In this study, we sought to further promote the rate of PrPSc amplification in the protein misfolding cyclic amplification technique using mouse transmissible spongiform encephalopathy models infected with either mouse‐adapted bovine spongiform encephalopathy or mouse‐adapted scrapie, Chandler strain. Here, we demonstrate that appropriate regulation of sonication dramatically accelerates PrPSc amplification in both strains. In fact, we reached maximum sensitivity, allowing the ultrasensitive detection of < 1 LD50 of PrPSc in the diluted brain homogenates, after only one or two reaction rounds, and in addition, we detected PrPSc in the plasma of mouse‐adapted bovine spongiform encephalopathy‐infected mice. We believe that these results will advance the establishment of a fast, ultrasensitive diagnostic test for transmissible spongiform encephalopathies.
Conformational stability and multistate unfolding of poly(A)‐specific ribonuclease
Authors: He Guang‐Jun , Zhang Ao , Liu Wei‐Feng , Cheng Yuan , Yan Yong‐Bin
Published: April 2009

Poly(A)‐specific ribonuclease (PARN) specifically catalyzes the degradation of the poly(A) tails of single‐stranded mRNAs in a highly processive mode. PARN participates in diverse and important intracellular processes by acting as a regulator of mRNA stability and translational efficiency. In this article, the equilibrium unfolding of PARN was studied using both guanidine hydrochloride and urea as chemical denaturants. The unfolding of PARN was characterized as a multistate process, but involving dissimilar equilibrium intermediates when denatured by the two denaturants. A comparison of the spectral characteristics of these intermediates indicated that the conformational changes at low concentrations of the chemical denaturants were more likely to be rearrangements of the tertiary and quaternary structures. In particular, an inactive molten globule‐like intermediate was identified to exist as soluble non‐native oligomers, and the formation of the oligomers was modulated by electrostatic interactions. An active dimeric intermediate unique to urea‐induced unfolding was characterized to have increased regular secondary structures and modified tertiary structures, implying that additional regular structures could be induced by environmental stresses. The dissimilarity in the unfolding pathways induced by guanidine hydrochloride and urea suggest that electrostatic interactions play an important role in PARN stability and regulation. The appearance of multiple intermediates with distinct properties provides the structural basis for the multilevel regulation of PARN by conformational changes.
Functional aspects of the solution structure and dynamics of PAF – a highly‐stable antifungal protein from Penicillium chrysogenum
Authors: Batta Gyula , Barna Teréz , Gáspári Zoltán , Sándor Szabolcs , Kövér Katalin E. , Binder Ulrike , Sarg Bettina , Kaiserer Lydia , Chhillar Anil K. , Eigentler Andrea , Leiter Éva , Hegedüs Nikoletta , Pócsi István , Lindner Herbert , Marx Florentine
Published: April 2009

Penicillium antifungal protein (PAF) is a promising antimycotic without toxic effects on mammalian cells and therefore may represent a drug candidate against the often lethal Aspergillus infections that occur in humans. The pathogenesis of PAF on sensitive fungi involves G‐protein coupled signalling followed by apoptosis. In the present study, the solution structure of this small, cationic, antifungal protein from Penicillium chrysogenum is determined by NMR. We demonstrate that PAF belongs to the structural classification of proteins fold class of its closest homologue antifungal protein from Aspergillus giganteus. PAF comprises five β‐strands forming two orthogonally packed β‐sheets that share a common interface. The ambiguity in the assignment of two disulfide bonds out of three was investigated by NMR dynamics, together with restrained molecular dynamics calculations. The clue could not be resolved: the two ensembles with different disulfide patterns and the one with no S–S bond exhibit essentially the same fold. 15N relaxation dispersion and interference experiments did not reveal disulfide bond rearrangements via slow exchange. The measured order parameters and the 3.0 ns correlation time are appropriate for a compact monomeric protein of this size. Using site‐directed mutagenesis, we demonstrate that the highly‐conserved and positively‐charged lysine‐rich surface region enhances the toxicity of PAF. However, the binding capability of the oligosaccharide/oligonucleotide binding fold is reduced in PAF compared to antifungal protein as a result of less solvent‐exposed aromatic regions, thus explaining the absence of chitobiose binding. The present study lends further support to the understanding of the documented substantial differences between the mode of action of two highly homologous antifungal proteins.
Effect of monovalent cations and G‐quadruplex structures on the outcome of intramolecular homologous recombination
Authors: Barros Paula , Boán Francisco , Blanco Miguel G. , Gómez‐Márquez Jaime
Published: April 2009

Homologous recombination is a very important cellular process, as it provides a major pathway for the repair of DNA double‐strand breaks. This complex process is affected by many factors within cells. Here, we have studied the effect of monovalent cations (K+, Na+, and NH4+) on the outcome of recombination events, as their presence affects the biochemical activities of the proteins involved in recombination as well as the structure of DNA. For this purpose, we used an in vitro recombination system that includes a protein nuclear extract, as a source of recombination machinery, and two plasmids as substrates for intramolecular homologous recombination, each with two copies of different alleles of the human minisatellite MsH43. We found that the presence of monovalent cations induced a decrease in the recombination frequency, accompanied by an increase in the fidelity of the recombination. Moreover, there is an emerging consensus that secondary structures of DNA have the potential to induce genomic instability. Therefore, we analyzed the effect of the sequences capable of forming G‐quadruplex on the production of recombinant molecules, taking advantage of the capacity of some MsH43 alleles to generate these kinds of structure in the presence of K+. We observed that the MsH43 recombinants containing duplications, generated in the presence of K+, did not include the repeats located towards the 5′‐side of the G‐quadruplex motif, suggesting that this structure may be involved in the recombination events leading to duplications. Our results provide new insights into the molecular mechanisms underlying the recombination of repetitive sequences.
Use of ultrasound to facilitate accurate femoral nerve block in the emergency department
Authors: Reid Nicole , Stella Julian , Ryan Matt , Ragg Michael
Published: April 2009

Objective:  To compare the accuracy of ultrasound (US)‐assisted femoral nerve blocks (FNB) with the fascial pop (FP) technique, examining the rates of success and complications.

Methods:  This is a prospective unblinded pseudo‐randomized controlled trial of US‐assisted versus FP FNB techniques. The primary outcome measure was nerve block stratified to level of blockade (intact, partial or complete) with FNB assessed by skin sensation. Participants were assessed at 15 and 60 min post nerve block.

Results:  Sixty‐seven patients were enrolled. Thirty‐four (50.7% [95% CI 44.7–56.8]) underwent the US‐assisted technique whereas thirty‐three (49.2% [95% CI 43.4–55.2]) underwent the FP technique. At 15 min, FNB using US was intact, partial or complete for 9 (26.5% [95% CI 22.5–30.4]), 15 (44.1% [95% CI 36.8–51.5]) and 10 (29.4% [95% CI 24.9–33.9]) patients, respectively, compared with 14 (42.4% [95% CI 35.3–49.6]), 17 (51.5% [95% CI 42.7–60.3]) and 2 (6.1% [95% CI 5.6–6.6]) patients, respectively (P = 0.038). There was no difference at 60 min. Complete block at 15 min was achieved in 10/34 patients (29% [95% CI 14.1–44.7]) in the US group and 2/33 patients (6% [95% CI −2.1–14.2]) in the FP group (P = 0.029); no difference was seen at 60 min. No complications were recorded in either group.

Conclusions:  A more complete blockade is achieved earlier using the US‐assisted technique. The US‐assisted technique will become the technique of choice for FNB in this department.
Review article: Indications for thoracolumbar imaging in blunt trauma patients: A review of current literature
Authors: O'Connor Enda , Walsham James
Published: April 2009

Thoracolumbar spine injury is a common complication of blunt multitrauma and up to one third of fractures are associated with spinal cord dysfunction. Delayed fracture diagnosis increases the risk of neurological complications. While validated screening guidelines exist for traumatic c‐spine injury equivalent guidelines for thoracolumbar screening are lacking. We conducted a literature review evaluating studies of thoracolumbar injury in trauma patients to generate indications for thoracolumbar imaging.

We performed MEDLINE and Pubmed searches using MeSH terms “Wounds, Nonpenetrating”, “Spinal Fractures”, “Spinal Injuries” and “Diagnostic Errors”, MeSH/subheading terms “Thoracic Vertebrae/injuries” and “Lumbar Vertebrae/injuries” and keyword search terms “thoracolumbar fractures”, “thoracolumbar injuries”, “thoracolumbar trauma”, “missed diagnoses” and “delayed diagnoses”. Limits and inclusion criteria were defined prior to searching.

We evaluated 16 articles; 5 prospective observational studies (1 cohort study) and 11 retrospective observational studies. Predictors of TL injury in prospective studies – high‐risk injury mechanism, distracting injury, impaired cognition, symptoms/signs of vertebral fracture and known cervical fracture – were defined and used to construct a decision algorithm, which in a total of 14189 trauma patients from all eligible studies recommended TL screening in 856(99.1%) of 864 patients with TL fractures and would probably have directed TL imaging in the remaining 8 patients.

There is limited low level evidence guiding surveillance TL imaging in adult blunt trauma patients. Despite this, we propose and evaluate an algorithm with a high negative predictive value for TL fractures. This should be incorporated into spinal injury assessment protocols.
Lost in translation: Maximizing handover effectiveness between paramedics and receiving staff in the emergency department
Authors: Owen Christine , Hemmings Lynn , Brown Terry
Published: April 2009

Objective:  The purpose of the present study is to investigate perceptions by paramedics and hospital receiving staff about what enables and constrains handover in the ED.

Methods:  This is a qualitative study of interviews with 19 paramedics, 15 nurses and 16 doctors (n = 50) from ambulance services and ED in two states of Australia.

Results:  Three main themes emerged that were evident at both sites and in the three professional groups. These were: difficulties in creating a shared cognitive picture, tensions between ‘doing’ and ‘listening’ and fragmenting communication.

Conclusion:  Recommendations arising from the present study as to how handover could be improved are the need for a common language between paramedics and staff in the ED, for shared experiences and understanding between the members of the team and for the development of a standardized approach to handover from paramedics to ED receiving staff.
The pulsar synchrotron: coherent radio emission
Authors: Contopoulos I.
Published: April 2009

We propose a simple physical picture for the generation of coherent radio emission in the axisymmetric pulsar magnetosphere that is quite different from the canonical paradigm of radio emission coming from the magnetic polar caps. In this first paper, we consider only the axisymmetric case of an aligned rotator. Our picture capitalizes on an important element of the magnetohydrodynamic (MHD) representation of the magnetosphere, namely the separatrix between the corotating closed-line region (the ‘dead zone’) and the open-field lines that originate in the polar caps. Along the separatrix flows the return current that corresponds to the main magnetospheric electric current emanating from the polar caps. Across the separatrix, both the toroidal and poloidal components of the magnetic field change discontinuously. The poloidal component discontinuity requires the presence of a significant annular electric current which has up to now been unaccounted for. We estimate the position and thickness of this annular current at the tip of the closed line region, and show that it consists of electrons (positrons) corotating with Lorentz factors on the order of 105, emitting incoherent synchrotron radiation that peaks in the hard X-rays. These particles stay in the region of highest annular current close to the equator for a path-length of the order of 1 m. We propose that, at wavelengths comparable to that path-length, the particles emit coherent radiation, with radiated power proportional to N2, where Nis the population of particles in the above path-length. We calculate the total radio power in this wavelength regime and its scaling with pulsar period and stellar magnetic field and show that it is consistent with estimates of radio luminosity based on observations.
DESCRIPTIVE SENSORY ANALYSIS OF TOOTHPASTE FLAVOR AND TEXTURE USING TWO SAMPLING METHODS: BRUSHING VERSUS SPOON TASTING
Authors: HIGHTOWER CARRITA A. , CHAMBERS IV EDGAR
Published: April 2009

Repeated testing of toothpaste using a brushing method can lead to dental sensitivity, which could compromise the effectiveness of descriptive evaluations. The objective of this research was to compare flavor and texture evaluations of toothpaste using two sampling methods, toothbrushing or spoon tasting, in a descriptive sensory analysis test. A highly trained descriptive sensory panel evaluated five commercially available toothpastes using the two sample delivery regimens. Changing the sample delivery method impacted key toothpaste attributes, including burn, nasal cooling, toothetch and associated flavor attributes such as overall mint, menthol and bitter, but no interaction of product and method was found for those attributes. The interaction between product and delivery technique, i.e., specific toothpastes react differently than others when the sampling technique is changed, occurred in graininess, foaminess, baking soda, oral cooling and tongue numbing. This research establishes that the delivery method for toothpaste during descriptive analysis has an impact on flavor evaluations. Although it is possible to use an alternate method, such as spoon tasting, for some toothpaste evaluations if the attributes of interest do not show interactions between product and method, researchers must give consideration to how alternate methods affect intensity of scores or other outcomes of the research.

PRACTICAL APPLICATIONS

Researchers seeking to use atypical sampling methods for various reasons (i.e., sample screening, limited resources, reducing evaluator's fatigue), especially for products such as toothpaste, must consider the objectives of a study and how an alternate technique will affect the outcome of the research. This research establishes that the delivery method of toothpaste during descriptive analysis has an impact on the flavor and texture evaluations. It is possible to use an alternate, such as sampling from a spoon for toothpaste evaluations, with the understanding that key attributes such as cooling and mint flavor will be amplified. The spoon method can be useful in screening when there is a need to efficiently gather information on a myriad of similar products, but it probably needs to be avoided in situations where products differ widely or key attributes are compromised.
Antimicrobial Activity of Catfish Gelatin Coating Containing Origanum (Thymus capitatus) Oil against Gram‐Negative Pathogenic Bacteria
Authors: Min B.J. , Oh J.‐H.
Published: April 2009

ABSTRACT:  The antimicrobial activity of origanum oil (OG) was determined against Salmonella Typhimurium and E. coli O157:H7. The efficacy of catfish gelatin coating containing selected concentrations of OG (0.5%, 1.0%, and 2.0%, v/v) was also investigated in catfish flesh irradiated, inoculated with both bacteria, and stored at selected temperatures. The antimicrobial activity of catfish gelatin coating was determined by cell counts during storage at 4 and 10 °C for 12 d. The color properties of catfish flesh coated with catfish gelatin containing OG were also measured. In the media, the inhibitory effects of OG against S. Typhimurium were greater than the inhibition effects against E. coli O157:H7, exhibiting complete inhibition against S. Typhimurium at the concentration greater than 0.5% (v/v). The incorporation of OG into catfish gelatin coating also inhibited both S. Typhimurium and E. coli O157:H7 in catfish flesh stored at 4 °C. The reduction of S. Typhimurium counts by gelatin coating containing 0%, 0.5%, 1%, 2% (v/v) OG were 0.58, 0.73, 1.16, and 1.76 log CFU/g, respectively, exhibiting the greatest effect at 2% (v/v) OG (P < 0.05). During storage at 10 °C, the reduction of S. Typhimurium counts by catfish gelatin coatings with 0%, 0.5%, 1%, and 2 % (v/v) OG were 0.67, 0.91, 1.32, and 2.05 log CFU/g, respectively. The incorporation of OG into catfish gelatin coating exhibited greater antimicrobial activity against S. Typhimurium than against E. coli O157:H7 at both temperatures. The lightness and yellowness of catfish flesh was not altered; however, the redness of catfish gelatin was decreased by catfish gelatin coating containing OG.
Saltiness and Acidity: Detection and Recognition Thresholds and Their Interaction Near the Threshold
Authors: Hatae Keiko , Takeutchi Fujio , Sakamoto Mariko , Ogasawara Yasushi , Akano Hirofumi
Published: April 2009

ABSTRACT:  Interaction of saltiness and acidity at the threshold level was studied employing 35 to 40 young female panelists. As a 1st step, the detection and recognition thresholds of salt, rice vinegar, and rice black vinegar have been measured for each panelist. To investigate the above interaction, the thresholds have been again measured for each panelist of salt, but this time, vinegar at half the concentration of each panelist's detection threshold was added to the salt solution. Similar measurement has been performed for vinegars with salt at half the concentration of each panelist's detection threshold. The data analysis has been done in 2 ways, namely, (1) by using Student's t‐test to detect the significant difference in average between the data with and without the added ingredient and (2) detecting significant deviations from zero in the individual shifts in 2 sensory tests among panelists who participated in the 2 measurements. In doing that, a conversion of the scale was necessary to correct the systematic skewness existing in the original data. As a result, both the detection and recognition thresholds of salt were decreased with the existence of the added vinegar ingredient (P < 0.001). This tendency was more pronounced with rice black vinegar than with rice vinegar. On the contrary, no significant changes in the threshold of both detection and recognition were observed when salt at the half concentration of the detection threshold was added to rice vinegar. The interaction therefore was found to be asymmetric.
Quality Changes of Highbush Blueberries Fruit Stored in CA with Different CO2Levels
Authors: Duarte Carolina , Guerra María , Daniel Peter , Camelo Andrés López , Yommi Alejandra
Published: April 2009

ABSTRACT: Quality changes of blueberries (Vacccinium corymbosumL. cv Brigitta) were evaluated during CA storage (0 °C) with different concentrations of CO2(5%, 10%, and 15%) combined with 5% O2, respectively. Atmospheric air (20.9% O2+ 0.03% CO2) was used as control. From samples taken at 0, 24, and 48 d of storage, unmarketable fruits and weight loss were recorded as well as color (h), firmness (g), soluble solid content (%), titratable acidity (% citric acid), ratio, and the monomeric anthocyanin content (ppm). At each sampling time, additional units were kept for 3 d at 10 °C to simulate retail holding conditions. Irrespective of gas concentration, 0.9% of the initial fresh weight was lost after 48 d at 0 °C. CA fruit had better quality than control at the 24 d sampling but due to the high number of unmarketable fruits, this advantage was not observed at 48 d at 0 °C. After 24 d of storage, fruits for CA treatments were more firm and had better color, with higher anthocyanin and acidity levels. Soluble solid content showed no significant differences throughout the cold storage period. Residual effect of CA storage was observed at the retail holding condition yielding better firmness, acidity, and ratio. However, the CO2level tested increased the number of unmarketable fruit in long‐term storage (48 d). Response of “Brigitta” blueberries to the different CO2levels studied was moderate and could be related to the high storage potential of this cultivar.
Characterization of Low Saturation Palm Oil Products after Continuous Enzymatic Interesterification and Dry Fractionation
Authors: Huey Saw Mei , Hock Chuah Cheng , Lin Siew Wai
Published: April 2009

ABSTRACT:  The lipase‐catalyzed interesterification of refined, bleached, deodorized palm olein with iodine value (IV) of 62 was studied in a pilot continuous packed‐bed reactor operating at 65 °C. Sn‐1,3 specific immobilized enzyme; Lipozyme® TL IM (Thermomyces Lanuginosa) from Novozyme A/S was used in this study. The interesterification reaction produced fully solidified fats at ambient temperature due to the production of trisaturated triacylglycerols (TAG) (PPP and PPS, where P = palmitic acid, S = stearic acid). The reaction also increased the percentage of triunsaturated TAG (OLL, OLO, and OOO, where O = oleic acid, L = linoleic acid). The interesterified product was then dry fractionated at temperatures of 9, 12, 15, 18, and 21 °C to separate the saturated fats from the unsaturated. The results show that IV of olein increased when the fractionation temperature (TFN) decreased. The highest IV of olein was 72, obtained from TFN at 9 °C. After interesterification and laboratory‐scale fractionation, the olein fractions contained higher unsaturation content ranging from 64.7% to 67.7% compared to the starting material (58.3%), while the saturation content was reduced from 41.7% to the range of 32.3% to 35.3%. The yields of these oleins were low with the range of 24.8% to 51.8% due to the limitation of the vacuum filtration. Ten kilograms of pilot‐scale fractionation with membrane press filter was used to determine the exact olein yield. At TFN of 12 °C, 67.1% of olein with saturation content of 33.9% was obtained.
Effects of pH Adjustment and Sodium Ions on Sour Taste Intensity of Organic Acids
Authors: Neta E.R.D. , Johanningsmeier S.D. , Drake M.A. , McFeeters R.F.
Published: April 2009

ABSTRACT:  Protonated organic acid species have been shown to be the primary stimuli responsible for sour taste of organic acids. However, we have observed that sour taste may be modulated when the pH of acid solutions is raised using sodium hydroxide. Objectives were to evaluate the effect of pH adjustment on sour taste of equimolar protonated organic acid solutions and to investigate the potential roles of organic anions and sodium ions on sour taste perception. Despite equal concentrations of protonated acid species, sour taste intensity decreased significantly with increased pH for acetic, lactic, malic, and citric acids (P < 0.05). Total organic anion concentration did not explain the suppression of sour taste in solutions containing a blend of 3 organic acids with constant concentration of protonated organic acid species and hydrogen ions and variable organic anion concentrations (R2= 0.480, P = 0.12). Sour taste suppression in these solutions seemed to be more closely related to sodium ions added in the form of NaOH (R2= 0.861, P = 0.007). Addition of 20 mM NaCl to acid solutions resulted in significant suppression of sour taste (P = 0.016). However, sour taste did not decrease with further addition of NaCl up to 80 mM. Presence of sodium ions was clearly shown to decrease sour taste of organic acid solutions. Nonetheless, suppression of sour taste in pH adjusted single acid solutions was greater than what would be expected based on the sodium ion concentration alone, indicating an additional suppression mechanism may be involved.