bluuebunny/crossref_metadata_2025 huggingface dataset:
Effort and Contribution of T‐DNA Insertion Mutant Library for Rice Functional Genomics Research in China: Review and Perspective
Authors: Chang Yuxiao , Long Tuan , Wu Changyin
Published: October 2012

With the completion of the rice (Oryza sativa L.) genome‐sequencing project, the rice research community proposed to characterize the function of every predicted gene in rice by 2020. One of the most effective and high‐throughput strategies for studying gene function is to employ genetic mutations induced by insertion elements such as T‐DNA or transposons. Since 1999, with support from the Ministry of Science and Technology of China for Rice Functional Genomics Programs, large‐scale T‐DNA insertion mutant populations have been generated in Huazhong Agricultural University, the Chinese Academy of Sciences and the Chinese Academy of Agricultural Sciences. Currently, a total of 372,346 mutant lines have been generated, and 58,226 T‐DNA or Tos17 flanking sequence tags have been isolated. Using these mutant resources, more than 40 genes with potential applications in rice breeding have already been identified. These include genes involved in biotic or abiotic stress responses, nutrient metabolism, pollen development, and plant architecture. The functional analysis of these genes will not only deepen our understanding of the fundamental biological questions in rice, but will also offer valuable gene resources for developing Green Super Rice that is high‐yielding with few inputs even under the poor growth conditions of many regions of Africa and Asia.
Nicotine hair concentrations in dogs exposed to environmental tobacco smoke: a pilot study
Authors: Knottenbelt C. M. , Bawazeer S. , Hammond J. , Mellor D. , Watson D. G.
Published: October 2012

Objectives

To investigate the association between dog hair nicotine concentration and owner‐reported exposure to environmental tobacco smoke to establish whether dogs are exposed to significant, detectable amounts of environmental tobacco smoke in the home.

Methods

Hair was collected from 23 dogs exposed to environmental tobacco smoke and from 15 dogs reportedly not exposed to environmental tobacco smoke. Hair was washed to remove adhered nicotine, digested in 1 M NaOH and extracted using solid phase extraction. Nicotine concentration was measured by high‐resolution mass spectrometry. Results were analysed using a Kruskall‐Wallis test and post hoc pair‐wise comparisons using a Mann–Whitney test to assess significance between exposure groups.

Results

The different exposure groups were significantly different (P < 0·001) for both hair and surface nicotine. Pair‐wise comparisons were significant at P < 0·05 for all categories except unexposed and occasionally exposed groups (P = 0·076).

Clinical Significance

Dog hair nicotine concentration appears to be strongly associated with reported exposure to environmental tobacco smoke. The range and median of hair nicotine concentration in dogs exposed to environmental tobacco smoke was similar to those reported in children. This suggests that dog hair could provide a useful method of determining the amount of environmental tobacco smoke exposure in all environments common to pets and children.
Does the Domestic Value Added Induced by China's Exports Really Belong to China?
Authors: Duan Yuwan , Yang Cuihong , Zhu Kunfu , Chen Xikang
Published: October 2012

Since 2001, the exports of foreign‐invested enterprises (FIEs) have accounted for more than 50 percent of China's total exports. As foreign capital occupies a high proportion of the total capital of FIEs, most FIEs' capital gains are foreign factor income. Although these gains are calculated as a part of China's GDP, they do not belong to China's national income. To determine the real contribution of exports to China's welfare, the present paper analyses the impact of exports on China's national income using a non‐competitive input–output model capturing processing trade. The results show that every US$1000 of China's exports generates US$506.8 of national income. The real contribution of exports to China's welfare is much smaller than what we expected. This suggests that China should endeavor to improve the gains from international markets or find another engine to maintain its economic growth.
Effect of microplasmin on the clearance of vitreous haemorrhage from an experimental model in rabbits
Authors: Gad Elkareem Ashraf M. , de Smet Marc D.
Published: October 2012

Purpose:  Microplasmin is known to alter the structure of the vitreous gel. The current experiments were designed to assess its ability to enhance clearance of an experimentally induced vitreous haemorrhage, and to compare it to ovine hyaluronidase.

Methods:  Twenty‐five rabbits were used for this experiment, divided into five groups; groups 1–3 are microplasmin‐treated eyes with 25, 75 and 125 μg, respectively. Group 4 treated with 55 IU of hyaluronidase, while group 5 was treated with normal saline (control). Eyes were injected in the mid‐vitreous with 0.05 ml of autologous blood obtained from the marginal ear vein. One week later, all the groups were injected with the test solution injected in mid‐vitreous as stated above. Clearance of the vitreous haemorrhage was assessed weekly indirect ophthalmoscopy for 8 weeks.

Results:  Microplasmin‐treated eyes showed a significant clearance of the vitreous haemorrhage in a dose‐dependent fashion, where group 3 (125 μg) had the highest clearance rate in comparison with control eyes. Hyaluronidase‐treated eyes showed a similar clearance rate as group 3. In addition, group 3 showed a complete posterior vitreous detachment, which did not develop in hyaluronidase‐treated eyes.

Conclusion:  Microplasmin may be a useful agent to accelerate the clearance of vitreous haemorrhage.
Brain antioxidant status in a high pressure–induced rat model of glaucoma
Authors: Ferreira Sandra M. , Lerner Fabian , Reides Claudia G. , Brunzini Ricardo , Llesuy Susana F.
Published: October 2012

Purpose:  The goal of the present study is to establish the antioxidant status in the brain of a high pressure–induced rat model.

Methods:  Ocular hypertension was induced in rats (n = 12) cauterizing two episcleral veins under a surgical microscope. A sham procedure (n = 12) was performed in the control group. The markers evaluated in the brain 7 days after surgery were as follows: spontaneous chemiluminescence, protein carbonylation, nitrite concentration, total reactive antioxidant potential (TRAP), ascorbic acid, glutathione, vitamin E and activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase.

Results:  Chemiluminescence in glaucoma was 55% higher than in controls (393 ± 20 cpm/mg protein, p < 0.001). Protein carbonylation in glaucoma was 93% higher than in controls (1.15 ± 0.18 nmol/mg protein, p < 0.001). Nitrite concentration was 5.30 ± 0.25 μM for glaucoma (controls 4.41 ± 0.24 μM, p < 0.05). Total reactive antioxidant potential decreased by 42% in glaucoma (controls 153 ± 14 μM Trolox, p < 0.001). Ascorbic acid was 67 ± 26 μM for glaucoma (controls 275 ± 22 μM, p < 0.001). Vitamin E was 0.58 ± 0.05 μmol/g organ for glaucoma (controls 1.10 ± 0.06 μmol/g organ, p < 0.01). Glutathione was 1.98 ± 0.13 μmol/g organ for glaucoma (controls 8.19 ± 0.71 μmol/g organ, p < 0.001). Superoxide dismutase and GPx were increased in glaucoma by 42 and 59%, respectively (p < 0.05).

Conclusions:  Reactive oxygen and nitrogen species were increased in glaucoma, the increase in chemiluminescence, protein carbonylation and nitrite levels could be evidenced by this situation. The decrease in nonenzymatic antioxidants and a compensatory increase in SOD and GPx activity may have been a consequence of an increase in oxidative processes.
Using corrected serum chloride and predicted bicarbonate concentrations to interpret acid‐base status in dogs
Authors: Meltesen Holly S. , Bohn Andrea A.
Published: October 2012

Background

Changes in water balance and the presence of unmeasured anions perturb the inverse relationship between serum chloride (Cl) and bicarbonate (HCO3) concentrations in people, affecting accurate interpretation of acid‐base status.

Objectives

The aim of this study was to demonstrate that corrected serum Cl and predictedHCO3concentrations, based on serum sodium (Na) concentration and anion gap (AG), would be inversely correlated and could be used to better characterize causes of acid‐base disorders in dogs.

Methods

In this retrospective study, electrolyte data from dogs with at least one abnormality in serum Na, Cl, orHCO3concentrations were analyzed. Profiles were classified before and after calculations using 2 methods, a modified Feldman and an institutional method, to correct Cl concentration and predictHCO3concentrations based on Na concentration andAG. Dogs were classified as low (L), normal (N), or high (H) based on Cl (first letter) andHCO3(second letter) concentrations, as follows:LL,LN,LH,NL,NN,NH,HL,HN, orHH.

Results

For profiles from 261 dogs, reclassifying corrected Cl and predictedHCO3concentrations resulted in a shift from the initial classification into a different one in 73% of dogs; in most cases, the shift was toLH,NN, orHLcategories. Albumin concentration was a significant factor in acid‐base balance.

Conclusions

When interpreting acid‐base status based on results of a standard biochemical panel, erroneous conclusions can be drawn if concentrations of Na, unmeasured anions, and albumin are not taken into account. The inverse relationship between serum Cl andHCO3concentrations may be used to identify frequent acid‐base disorders as well as to unmask abnormalities obscured by irregularities in water balance orAG.
Science Talk: Preservice Teachers Facilitating Science Learning in Diverse Afterschool Environments
Authors: Cartwright Tina Johnson
Published: October 2012

The purpose of this study was to assess the impact a community‐based service learning program might have on preservice teachers' science instruction during student teaching. Designed to promote science inquiry, preservice teachers learned how to offer students more opportunities to develop their own ways of thinking through utilization of an afterschool science program that provided them extended opportunities to practice their science teaching skills. Three preservice teachers were followed to examine and evaluate the transfer of this experience to their student teaching classroom. Investigation methods included field observations and semi‐structured, individual interviews. Findings indicate that preservice teachers expanded their ideas of science inquiry instruction to include multiple modes of formative assessment, while also struggling with the desire to give students the correct answer. While the participants' experiences are few in number, the potential of afterschool teaching experience serving as an effective learning experience in preservice teacher preparation is significant. With the constraints of high‐stakes testing, community‐based service learning teaching opportunities for elementary and middle‐school preservice teachers can support both the development and refinement of inquiry instruction skills.
Rate of Change: AP Calculus Students' Understandings and Misconceptions After Completing Different Curricular Paths
Authors: Teuscher Dawn , Reys Robert E.
Published: October 2012

This study examined Advanced Placement Calculus students' mathematical understanding of rate of change, after studying four years of college preparatory (integrated or single‐subject) mathematics. Students completed the Precalculus Concept Assessment (PCA) and two open‐ended tasks with questions about rates of change. After adjusting for prior achievement with the Iowa Algebra Aptitude Test, students from these two paths performed comparably (F = 3.54, p = .063) on the PCA. Student errors on the three instruments revealed a lack of understanding of the interpretation or meaning of rate of change regardless of the curricular path. Students successfully calculated the rate of change of linear functions; however, when the function was not linear, students struggled to calculate it, model it on a graph, or interpret it in a real‐world context.
The Effect of a Modified Moore Method on Attitudes and Beliefs in Precalculus
Authors: Bailey Brad , Cooper Thomas E. , Briggs Karen S.
Published: October 2012

As part of a study on the effects of teaching with a Modified Moore Method (MMM), a survey containing 20 items from Schoenfeld's (1989) investigation of attitudes and beliefs about mathematics was administered to students in undergraduate precalculus classes. The study included one section of precalculus taught with an MMM, a student‐centered and inquiry‐based teaching method, and two sections taught using traditional lecture methods. The survey was administered one week into the semester, following the drop/add date, and during the last week of classes. In this paper, we discuss the findings of the attitudes and beliefs portions of the survey and correlations with scores on a common final exam. We looked for differences between the MMM and traditional sections as well as gender differences. There were only a few differences in the attitudes and beliefs among the students, although there were more changes for females than males and all the significant differences were positive. The correlation between attitudes and beliefs and final exam scores was much stronger in the traditionally taught classes than in the MMM class. When separated by gender, only the reported attitudes and beliefs of the females in the traditional class significantly correlated with final exam scores.
Proteomic evidence of a paedomorphic evolutionary process within a marine snail species: a strategy for adapting to extreme ecological conditions?
Authors: Diz A. P. , Páez de la Cadena M. , Rolán‐Alvarez E.
Published: October 2012

The exposed and sheltered ecotypes of the marine snail Littorina saxatilis from European rocky shores are considered a key model system to study adaptation and ecological speciation. Previous studies showed that two ecotypes (RB and SU) of this species in NW Spain have adapted differently to different shore levels and microhabitats. In order to understand how this divergent adaptive process has been accomplished, we followed a quantitative proteomic approach to investigate the proteome variation in a number of different biological factors, that is, ecotype, ontogeny and their interactions. This approach allowed testing the hypothesis that one of the ecotypes has evolved by paedomorphosis, and also whether or not the molecular mechanisms related to ecotype differentiation are set up in early developmental stages. Additionally, the identification of some candidate proteins using mass spectrometry provides some functional insights into these evolutionary processes. Results from this study provided evidence of higher ontogenetic differentiation at proteome level in the RB (metamorphic) than in SU (paedomorphic) ecotype that point to the possibility of juvenile stage retention in this latter ecotype. The level of protein expression (proteome) differences between ecotypes maintained nearly constant from late embryonic stages to adulthood, although some proteins involved in these changes considerably differed in embryonic compared to other ontogenetic stages. Paedomorphosis may be the evolutionary response of the SU ecotype of solving the trade‐off during sexually immaturity that is caused by the evolution of small size arising from adaptation to the wave‐exposed habitat. Some potential candidate genes of adaptation related to energetic metabolism have been identified, providing a promising baseline for future functional analyses.
Effects of different dietary protein levels and DL‐methionine supplementation on hair growth and pelt quality in mink (Neovision vision)
Authors: Zhang H. H. , Jiang Q. K. , Sun W. L. , Xu C. , Cong B. , Yang F. H. , Li G. Y.
Published: October 2012

The effect of different dietary protein levels and DL‐methionine (Met) supplementation on hair growth and the resulting pelt quality in mink was studied. Four groups of male mink were fed with four isocaloric diets containing 32% (P32), 24% (P24), 16% (P16) or P24+Met (0.8%) crude protein of dry matter (DM) from September to December. Skin biopsies were taken at the pelting. Histological techniques and computer‐assisted light microscopy were used to determine the ratio of activity (ROA) of under hairs and guard hairs respectively. The results showed that when the dietary protein level reduced from 32% to 16%, body length, number and diameter of under hairs and guard hairs of minks declined, and pelt length and pelt weight of minks decreased significantly (p < 0.05). These parameters were similar between P32 and P24 with Met supplementation (p > 0.05). The hair follicle density of the winter coat was not influenced by the dietary protein levels and Met supplementation (p > 0.05). Low‐protein diets content led to a reduction of hair follicle developing to next phase. It was documented that 24% crude protein of DM with Met supplementation during growing‐furring period was sufficient for minks to express their genetic capacity to develop hair follicles and achieve the prime fur characteristics. Overall this study demonstrated that hair growth and hair properties in pelts are very dependent on the dietary protein and Met supply in the growing‐furring period of minks.
Ulva (Chlorophyta, Ulvales) Biodiversity in the North Adriatic Sea (Mediterranean, Italy): Cryptic Species and New Introductions
Authors: Wolf Marion A. , Sciuto Katia , Andreoli Carlo , Moro Isabella
Published: October 2012

Ulva Linnaeus (Ulvophyceae, Ulvales) is a genus of green algae widespread in different aquatic environments. Members of this genus show a very simple morphology and a certain degree of phenotypic plasticity, heavily influenced by environmental conditions, making difficult the delineation of species by morphological features alone. Most studies dealing with Ulva biodiversity in Mediterranean waters have been based only on morphological characters and a modern taxonomic revision of this genus in the Mediterranean is not available. We report here the results of an investigation on the diversity of Ulva in the North Adriatic Sea based on molecular analyses. Collections from three areas, two of which subject to intense shipping traffic, were examined, as well as historical collections of Ulva stored in the Herbarium Patavinum of the University of Padova, Italy. Molecular analyses based on partial sequences of the rbcL and tufA genes revealed the presence of six different species, often with overlapping morphologies: U. californica Wille, U. flexuosa Wulfen, U. rigida C. Agardh, U. compressa Linnaeus, U. pertusa Kjellman, and one probable new taxon. U. californica is a new record for the Mediterranean and U. pertusa is a new record for the Adriatic. Partial sequences obtained from historical collections show that most of the old specimens are referable to U. rigida. No specimens referable to the two alien species were found among the old herbarium specimens. The results indicate that the number of introduced seaweed species and their impact on Mediterranean communities have been underestimated, due to the difficulties in species identification of morphologically simple taxa as Ulva.
Identification of specific regions in hepatitis C virus core, NS2 and NS5A that genetically interact with p7 and co‐ordinate infectious virus production
Authors: Gouklani H. , Beyer C. , Drummer H. , Gowans E. J. , Netter H. J. , Haqshenas G.
Published: October 2012

The p7 protein of hepatitis C virus (HCV) is a small, integral membrane protein that plays a critical role in virus replication. Recently, we reported two intergenotypic JFH1 chimeric viruses encoding the partial or full‐length p7 protein of the HCV‐A strain of genotype 1b (GT1b; Virology; 2007; 360:134). In this study, we determined the consensus sequences of the entire polyprotein coding regions of the wild‐type JFH1 and the revertant chimeric viruses and identified predominant amino acid substitutions in core (K74M), NS2 (T23N, H99P) and NS5A (D251G). Forward genetic analysis demonstrated that all single mutations restored the infectivity of the defective chimeric genomes suggesting that the infectious virus production involves the association of p7 with specific regions in core, NS2 and NS5A. In addition, it was demonstrated that the NS2 T23N facilitated the generation of infectious intergenotypic chimeric virus encoding p7 from GT6 of HCV.
The val66met polymorphism of brain‐derived neurotrophic factor is associated with human esophageal hypersensitivity
Authors: Vasant D. H. , Payton A. , Mistry S. , Thompson D. G. , Hamdy S.
Published: October 2012

Background  Recent evidence implicates brain‐derived neurotrophic factor (BDNF) in visceral hypersensitivity and pain in functional gastrointestinal disorders. We hypothesized that presence of the val66met polymorphism in the BDNF gene would be linked to increased esophageal sensitivity to electrical stimulation.

Methods  A total of 39 healthy volunteers (20 males, mean age 30) compliant with inclusion criteria after screening procedures were genotyped for BDNF polymorphisms and completed an Hospital Anxiety and Depression Scale (HADS) questionnaire. Sensory (ST) and pain (PT) thresholds in the proximal (PE) and distal (DE) esophagus were determined using electrical stimuli to a swallowed intraluminal catheter with bipolar electrodes by an investigator blinded to the subjects’ genotype. For comparison, somatic ST and PT (hand and foot) were also tested. HADS scores together with esophageal and somatic thresholds were then correlated with BDNF polymorphism status.

Key Results  Eleven of 39 (28%) volunteers had at least one Met allele (Met carriers). When compared with Val/Val, Met carriers had lower esophageal PT (Median PT [mA]: Val/Val vs Met carriers, PE; 49.4 vs 44.3, P = 0.033, DE: 63.8 vs 55.4, P = 0.045) with higher proportion of Val/Val subjects in the upper quartile for PT in both PE (P = 0.021) and DE (P = 0.033), yet similar somatic PT (Median PT [mA] Hand; 33.6 vs 38.0, P = 0.22, Foot; 44.7 vs 44.0, P = 0.48). Sensitivity results were independent of anxiety (P = 0.66) and depression (P = 0.33) scores.

Conclusions & Inferences  val66met BDNF polymorphisms are associated with increased esophageal sensitivity to experimental electrical stimulation. Thus, BDNF genotype may be a useful biomarker for electrical sensitivity in the healthy human esophagus.
The in vitro study of ursolic acid and oleanolic acid inhibiting cariogenic microorganisms as well as biofilm
Authors: Zhou L , Ding Y , Chen W , Zhang P , Chen Y , Lv X
Published: October 2012

Objective

The aim of this study was to examine the effect of ursolic acid (UA) and oleanolic acid (OA), triterpenoid compounds that are isolated from many edible and medicinal plants, on cariogenic microorganisms and biofilms.

Methods

A microtitre plate dilution assay was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of UA and OA against two Actinomyces spp. and four Streptococcus spp. The antibacterial activity of UA and OA was assessed by crystal violet staining, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM).

Results

UA and OA displayed differential antibacterial activities against the six tested bacteria, with UA showing greater antibacterial activity than OA. Furthermore, the two drugs had greater antibacterial activity against Actinomyces spp. than Streptococcus spp. UA and OA at 1/4 MIC can reduce bacterial biofilm formation, whereas higher UA concentrations displayed antibacterial activity against Actinomyces viscosus and Streptococcus mutans in mature biofilms. For instance, 2.0 mg ml−1 UA was sufficient to kill an A. viscosus biofilm.

Conclusions

UA and OA inhibit the growth of cariogenic microorganisms, which suggests that UA and OA have considerable potential as antibacterial agents for dental caries prevention.
Peroxisome proliferator‐activated receptor (PPAR) γ polymorphism, vitamin D, bone mineral density and periodontitis in postmenopausal women
Authors: Wang Y , Sugita N , Yoshihara A , Iwasaki M , Miyazaki H , Nakamura K , Yoshie H
Published: October 2012

Objectives

PPARg regulates bone metabolism and inflammation. Our previous study suggested PPARg Pro12Ala polymorphism to represent a susceptibility factor for periodontitis in pregnant Japanese women. Several recent papers have drawn attention to a possible link between low bone mineral density (BMD) and periodontitis in postmenopausal women. Since the pathogenesis for both involve bone remodeling, they might share common risk factors such as gene polymorphisms and vitamin D level. The present study investigated possible associations between the PPARgPro12Ala polymorphism, periodontitis, BMD and serum 25(OH)D in postmenopausal Japanese women.

Materials and Methods

PPARgPro12Ala genotypes of 359 women were determined by PCR‐RFLP. BMD and periodontal parameters of each woman were measured. Serum 25(OH)D levels were determined by radioimmunoassay.

Results

PPARgPro12Ala polymorphism was not associated with periodontitis or BMD as an independent factor. Serum 25(OH)D was significantly higher in Ala allele carriers compared to non‐carriers. Only in the Ala allele carriers, positive correlations were found between mean clinical attachment level and BMD, between BMD and 25(OH)D, and between percentage of sites with probing depth ≥4 mm and 25(OH)D.

Conclusions

PPARgPro12Ala polymorphism was not independently associated with periodontitis or BMD. However, the polymorphism might be a modulator of the relationship between the two conditions in postmenopausal Japanese women.
A chloroplast‐derived Toxoplasma gondii GRA4 antigen used as an oral vaccine protects against toxoplasmosis in mice
Authors: del L. Yácono María , Farran Inmaculada , Becher Melina L. , Sander Valeria , Sánchez Vanesa R. , Martín Valentina , Veramendi Jon , Clemente Marina
Published: October 2012

The parasitic protozoan Toxoplasma gondii, the causal agent of toxoplasmosis, can infect most mammals and birds. In human medicine, T. gondii can cause complications in pregnant women and immunodeficient individuals, while in veterinary medicine, T. gondii infection has economic importance due to abortion and neonatal loss in livestock. Thus, the development of an effective anti‐Toxoplasma vaccine would be of great value. In this study, we analysed the expression of T. gondii GRA4 antigen by chloroplast transformation (chlGRA4) in tobacco plants and evaluated the humoral and cellular responses and the grade of protection after oral administration of chlGRA4 in a murine model. The Western blot analysis revealed a specific 34‐kDa band mainly present in the insoluble fractions. The chlGRA4 accumulation levels were approximately 6 μg/g of fresh weight (equivalent to 0.2% of total protein). Oral immunization with chlGRA4 resulted in a decrease of 59% in the brain cyst load of mice compared to control mice. ChlGRA4 immunization elicited both a mucosal immune response characterized by the production of specific IgA, and IFN‐γ, IL‐4 and IL‐10 secretion by mesenteric lymph node cells, and a systemic response in terms of GRA4‐specific serum antibodies and secretion of IFN‐γ, IL‐4 and IL‐10 by splenocytes. Our results indicate that oral administration of chlGRA4 promotes the elicitation of both mucosal and systemic balanced Th1/Th2 responses that control Toxoplasma infection, reducing parasite loads.
Influence of nitrate supplementation on VO2 kinetics and endurance of elite cyclists
Authors: Christensen P. M. , Nyberg M. , Bangsbo J.
Published: October 2012

The present study examined if an elevated nitrate intake would improve VO2 kinetics, endurance, and repeated sprint capacity in elite endurance athletes.

Ten highly trained cyclists (72 ± 4 mL O2/kg/min, mean ± standard deviation) underwent testing for VO2 kinetics (3 × 6 min at 298 ± 28 W), endurance (120 min preload followed by a 400‐kcal time trial), and repeated sprint capacity (6 × 20 s sprints, recovery 100 s) during two 6‐day periods in randomized order with a daily ingestion of either 0.5 L beetroot (BR) juice to increase nitrate levels or a 0.5 L placebo (PLA) drink with blackcurrant juice. Plasma NOx (nitrate + nitrite) levels were higher (P < 0.01) in BR (147 ± 102 and 159 ± 103 μM after 4 and 6 days of beverage intake, respectively) compared with PLA (41 ± 10 and 40 ± 7 μM). VO2 kinetics and exercise economy were the same in BR and PLA. Time‐trial performance was similar with an average completion time of 18:20 and 18:37 min:s in BR and PLA, respectively, with average power outputs of 290 ± 43 W in BR and 285 ± 44 W in PLA. Peak and mean power during repeated sprinting were similar in BR and PLA.

In contrast to observations in moderately trained subjects intake of BR juice had no effect on VO2 kinetics and performance in elite cyclists.
Are the infrared thermography findings skin temperature‐dependent? a study on neck pain patients
Authors: Zaproudina Nina , Airaksinen Olavi , Närhi Matti
Published: October 2012

Background

Skin temperature (Tsk) disorders have been proposed as sign of impaired innervation in several conditions, but the influence of different factors on the infrared thermography (IRT) findings remains unclear.

Methods

The relations between the Tsk and δT (side‐to‐side temperature difference) values, and influence of age, gender, anthropometric characteristics and pain intensity on those values were analysed in non‐specific neck pain (NP) patients (n = 91) using mixed model analysis. IRT findings were also compared in subgroups of NP patients: with cold (CHNPP, n = 21) or warm hands (WHNPP, n = 56) and healthy controls, with cold (CHC, n = 11) or warm hands (WHC, n = 19). Also, the stability of δT values in CHNPP was examined.

Results

Only the area of measurement and the actual Tsk influenced the δT values. CHNPP demonstrated higher δT values in distal parts, compared with WHNPP and controls, but those values vanished when their hands turned warm. δT values in CHNPP were related to the pain intensity. The findings of WHNPP and WHC did not differ.

Conclusion

Our results suggest that the δT values as signs of impaired Tsk regulation are dynamic and better detectable in cold skin. The results underline the need of caution in interpretation of IRT findings.
Identification of a novel allele, HLA‐B*37:04:02, from a registered donor of the China Marrow Donor Program
Authors: Li J.‐P. , Li X.‐F. , Zhang X. , Zhang K.‐L. , Liu X.‐Z.
Published: October 2012

B*37:04:02 has 1 nt change from B*37:04:01 at nt 618 where G→A (codon 206 GCG→GCA) resulting in no coding change.
Does Final Market Demand Elasticity Influence the Location of Export Processing? Evidence from Multinational Decisions in China
Authors: Liu Xuepeng , Lovely Mary E. , Ondrich Jan
Published: October 2012

Given the importance many developing countries attach to attracting foreign investors engaged in export‐processing activities, surprisingly little is known about the sensitivity of these investors to local wage differences and the role played by final product market conditions. Using data on 2,884 foreign‐invested manufacturing projects in China, we estimate the importance of host province wages to firm’s location choice and investigate how this sensitivity varies with demand conditions facing the industry in China’s largest export market, the United States. We use the profit function to show theoretically that firms’ ability to pass wage costs through to final markets matters for location choice and we test the implications of the theory using a control‐function technique for conditional logit developed byPetrin and Train. As predicted, we find that investors facing more elastic demand in the US market are more sensitive to wages across export‐processing locations. Taking both the factor intensity of the activity and final market demand elasticity into account, we find that investors producing homogenous goods, such as metals, chemicals, and food processing, are more likely to be attracted by relatively low wages than those producing differentiated goods. We also find that while OECD investors are more responsive to wage differences than are investors from Hong Kong, Taiwan and Macau, they are less likely to choose a location that has received a large share of prior foreign investment.
α1‐Adrenergic receptor control of the cerebral vasculature in humans at rest and during exercise
Authors: Purkayastha Sushmita , Saxena Ashwini , Eubank Wendy L. , Hoxha Besim , Raven Peter B.
Published: October 2012

New findings

What is the central question of this study?

Despite the abundance of sympathetic nerve fibres emanating from the cervical and stellate ganglia that innervate the cerebral arteries, the role of the sympathetic nervous system in regulation of cerebral vasculature in humans remains equivocal.

What is the main finding and its importance?

The findings from this study support the role of the sympathetic nervous system, mediated by activation of α1‐adrenoreceptors, in dynamic cerebral autoregulation and cerebral vascular tone at rest and during moderate dynamic exercise. Blockade of the α1‐adrenoreceptors impaired dynamic cerebral autoregulation and attenuated any increases in cerebral vascular tone during moderate dynamic exercise in healthy humans.

We tested the hypothesis that pharmacological blockade of α1‐adrenoreceptors (by prazosin), at rest and during steady‐state dynamic exercise, would impair cerebral autoregulation and result in cerebral vasodilatation in healthy humans. In 10 subjects, beat‐to‐beat mean arterial pressure and mean middle cerebral artery blood velocity were determined at rest and during low (Ex90) and moderate workload (Ex130) on an upright bicycle ergometer without and with prazosin. Plasma noradrenaline concentrations increased significantly from rest to Ex130 during control conditions (from 1.8 ± 0.2 to 3.2 ± 0.3 pmol (ml plasma)−1). In the control conditions, the transfer function gain between mean arterial pressure and mean middle cerebral artery blood velocity in the low‐frequency range was decreased at Ex90 (P= 0.035) and Ex130 (P= 0.027) from rest. A significant increase in critical closing pressure (CCP) was also observed in the control conditions from rest to Ex90 to Ex130 (from 18 ± 3 to 24 ± 4 to 31 ± 4 mmHg). An average of 74 ± 2% blockade of blood pressure response was achieved with oral prazosin. Following blockade, plasma noradrenaline concentrations further increased at rest and during Ex130 from the control value (from 2.6 ± 0.3 to 4.4 ± 0.5 pmol (ml plasma)−1). Prazosin also resulted in an increase in low‐frequency gain (P < 0.003) compared with the control conditions. Prazosin blockade abolished the increases in CCP during Ex130 and increased the cerebrovascular conductance index (P= 0.018). These data indicate that in the control conditions a strengthening of cerebral autoregulation occurred with moderate dynamic exercise that is associated with an increase in CCP as a result of the exercise‐mediated augmentation of sympathetic activity. Given that α1‐adrenergic receptor blockade attenuated the increase in dynamic cerebral autoregulation and CCP, we conclude that increases in sympathetic activity have a role in establishing cerebral vascular tone in humans.
Dopamine D1 receptors control exercise hyperpnoea in mice
Authors: Iwase Michiko , Izumizaki Masahiko , Tsuchiya Naoto , Homma Ikuo
Published: October 2012

New findings

What is the central question of this study?

Measurement of ventilation (as well as simultaneous recording of ventilation and pulmonary gas exchange) in exercising mice has not been studied thoroughly. We evaluated ventilation in association with metabolic changes during constant‐load exercise in mice and examined the role of D1 receptors in addition to the D2 receptors previously studied. This reliable method can be used in gene‐manipulated mice.

What is the main finding and its importance?

We showed that the D1 receptors participate in resting ventilation and exercise hyperpnoea in parallel with metabolic changes during the steady state in mice. The metabolic control of D1 receptors was important for maintenance of the steady state.

Previously, we undertook simultaneous recording of ventilation and pulmonary gas exchange in mice and revealed that dopamine D2 receptors participate in exercise hyperpnoea via behavioural control of ventilation with unchanged pulmonary gas exchange. Here, we examined the hypothesis that D1 receptors also contribute to exercise hyperpnoea using a D1 receptor antagonist (SCH 23390; SCH) that crosses the blood–brain barrier, with the same recording technique and protocol as in the previous study. The respiratory responses of mice injected with saline or SCH (50 μg (kg body weight)−1, i.p.) were compared during constant‐load exercise at 6 m min−1. Each mouse was set in an airtight treadmill chamber equipped with a differential pressure transducer and open‐circuit system with a mass spectrometer. At rest, SCH‐injected mice had significantly reduced respiratory frequency, minute ventilation and pulmonary gas exchange compared with saline‐injected mice. Ventilation during hyperoxic gas inhalation and hypercapnic ventilatory responses between groups were similar. Abrupt increases and sequential declines to the steady‐state level were produced by treadmill exercise in both groups of mice. Treatment with SCH lowered the increased levels of respiratory frequency, tidal volume and minute ventilation during the steady state, as well as reducing the O2 uptake, CO2 output and body temperature throughout treadmill exercise. These data suggest that D1 receptors contribute to a resting ventilation level and exercise hyperpnoea during the steady state in parallel with metabolic changes. Notably, the metabolic control of D1 receptors was important for maintenance of the steady state, and D1 receptors in hypothalamic nuclei could be involved in this modulation.
A Continuum Approach to Thermomass Theory
Authors: Sellitto A. , Cimmelli V. A.
Published: October 2012

A continuum approach to the thermomass theory for nonlinear heat transport is developed and its compatibility with the general framework of continuum thermodynamics is investigated. The heat flux is supposed to depend on the absolute temperature together with a vectorial internal variable, which is proportional to the drift velocity of the heat carriers. A generalized heat-transport equation, which is capable to bring Fourier, Maxwell–Cattaneo–Vernotte and thermomass-theory equations as special cases is derived. Propagation of heat waves along a nonequilibrium steady state is analyzed as well.
Thermal Modeling and Analysis of a Thermal Barrier Coating Structure Using Non-Fourier Heat Conduction
Authors: Akwaboa Stephen , Mensah Patrick , Beyazouglu Ebubekir , Diwan Ravinder
Published: October 2012

This paper presents a numerical solution of the hyperbolic heat conduction equation in a thermal barrier coating (TBC) structure under an imposed heat flux on the exterior of the TBC. The non-Fourier heat conduction equation is used to model the heat conduction in the TBC system that predicts the heat flux and the temperature distribution. This study presents a more realistic approach to evaluate in-service performance of thin layers of TBCs typically found in hot sections of land based and aircraft gas turbine engines. In such ultrafast heat conduction systems, the orders of magnitude of the time and space dimensions are extremely short which renders the traditional Fourier conduction law, with its implicit assumption of infinite speed of thermal propagation, inaccurate. There is, therefore, the need for an advanced modeling approach for the thermal transport phenomenon taking place in microscale systems. A hyperbolic heat conduction model can be used to predict accurately the transient temperature distribution of thermal barrier structures of turbine blades. The hyperbolic heat conduction equations are solved numerically using a new numerical scheme codenamed the mean value finite volume method (MVFVM). The numerical method yields minimal numerical dissipation and dispersion errors and captures the discontinuities such as the thermal wave front in the solution with reliable accuracy. Compared with some traditional numerical methods, the MVFVM method provides the ability to model the behavior of the single phase lag thermal wave following its reflection from domain boundary surfaces. In addition, parametric studies of properties of the substrate on the temperature and the heat flux distributions in the TBC revealed that relaxation time of the substrate material, unlike the thermal diffusivity and thermal conductivity has very little effect on the transient thermal response in the TBC. The study further showed that for thin film structures subject to short time durations of heat flux, the hyperbolic model yields more realistic results than the parabolic model.
Thermal Actuation Using Nanocomposites: A Computational Analysis
Authors: Xu Y. , Li G.
Published: October 2012

In this paper, we propose the use of Si/Ge nanocomposite materials to improve the performance of microthermal actuators. Nanocomposites with a high electrical to thermal conductivity ratio can facilitate a rapid temperature change within a short distance, enabling a high temperature increase in a large region of the actuator beams. The total structural thermal expansion and, consequently, the actuation distance can be increased significantly. A top-down quasi-continuum multiscale model is presented for the computational analysis of nanocomposite based thermal actuators. In the multiscale model, the thermo-mechanical response of the actuator due to Joule heating is modeled using classical continuum theories, while the thermal and electrical properties of doped Si and Si/Ge nanocomposite materials are obtained from atomistic level descriptions. An iterative procedure is carried out between the calculations at the two length scales until a self-consistent solution is obtained. Numerical results indicate that incorporating Si/Ge nanocomposites in thermal actuators can significantly increase their energy efficiency and mechanical performance. In addition, parametric studies show that the size of the nanocomposite region and atomic percentage of the material components have significant effects on the overall performance of the actuators.
Solution of the Radiative Transfer Equation in Three-Dimensional Participating Media Using a Hybrid Discrete Ordinates: Spherical Harmonics Method
Authors: Sankar Maathangi , Mazumder Sandip
Published: October 2012

In this article, a new hybrid solution to the radiative transfer equation (RTE) is proposed. Following the modified differential approximation (MDA), the radiation intensity is first split into two components: a “wall” component, and a “medium” component. Traditionally, the wall component is determined using a viewfactor-based surface-to-surface exchange formulation, while the medium component is determined by invoking the first-order spherical harmonics (P1) approximation. Recent studies have shown that although the MDA approach is accurate over a large range of optical thicknesses, it is prohibitive for complex three-dimensional geometry with obstructions, both from a computational efficiency as well as memory standpoint. The inefficiency stems from the use of the viewfactor-based approach for determination of the wall-emitted component. In this work, instead, the wall component is determined directly using the control angle discrete ordinates method (CADOM). The new hybrid method was validated for both two-dimensional (2D) and three-dimensional (3D) geometries against benchmark Monte Carlo results for gray media in which the optical thickness was varied over a large range. In all cases, the accuracy of the hybrid method was found to be within a few percent of Monte Carlo results, and comparable to the solutions of the RTE obtained directly using CADOM. Finally, the new hybrid method was explored for 3D nongray media in the presence of reflecting walls and various scattering albedos. As a noteworthy advantage, irrespective of the conditions used, it was always found to be computationally more efficient than standalone CADOM and up to 15 times more efficient than standalone CADOM for optically thick media with strong scattering.
Heat and Mass Transfer in Power-Law Nanofluids Over a Nonisothermal Stretching Wall With Convective Boundary Condition
Authors: Khan Waqar A. , Reddy Gorla Rama Subba
Published: October 2012

A boundary layer analysis that has been presented for the heat and mass transfer in power-law nanofluids over a stretching surface with convective boundary condition are investigated numerically. The surface nanoparticle concentration is kept constant. A power-law model is used for non-Newtonian fluids, whereas Brownian motion and thermophoresis effects are incorporated in the nanofluid model. A similarity transformation is used to reduce mass, momentum, thermal energy, and nanoparticles concentration equations into nonlinear ordinary differential equations which are solved numerically by using a finite difference method. The effects of nanofluid parameters, suction/injection, and convective parameters and generalized Pr and Le numbers on dimensionless functions, skin friction, local Nusselt, and Sherwood numbers are shown graphically. The quantitative comparison of skin friction and heat transfer rates with the published results for special cases is shown in tabular form and is found in good agreement.
Optimized Laminar Axisymmetrical Nozzle Design Using a Numerically Validated Thwaites Method
Authors: Versailles Philippe , Bergthorson Jeffrey M.
Published: October 2012

This paper presents the Thwaites method as an accurate and efficient design tool for laminar, axisymmetrical nozzles. Based on historical developments, it is improved to describe internal flows with highly favorable pressure gradients in cylindrical coordinates. The calculation of the core flow velocity distribution based on the continuity equation is proposed as a replacement to other sophisticated numerical methods. A remarkably good agreement is obtained when comparing the results of the current Thwaites method against those of computational fluid dynamics (CFD) simulations, for which the integral boundary layer thicknesses are calculated with equations developed from first principles in the course of the work. This consistency among the results and the low time and resource costs of the Thwaites method confirm its applicability and usefulness as an engineering design and optimization tool.
A Multizone Model of an Economizer in a 600 MW Boiler Unit
Authors: Jizhou Wang , Yanping Zhang , Yu Li , Shuhong Huang
Published: October 2012

In this paper, a multizone model is developed to investigate the performance of an economizer under all conditions. The model primarily determines the economizer’s distribution parameters under all conditions with a small computational cost. Both the steady-state and dynamic behavior are calculated. These results are shown to be accurate and reliable using a computational fluid dynamic (CFD) model and the operational data obtained from a 600 MW boiler unit in Hubei province, China. Additionally, the model is used to predict the distribution characteristics during some fault conditions.