bluuebunny/crossref_metadata_2025 huggingface dataset:
Strain–Stress Analysis of AlGaN/GaN Heterostructures With and Without an AlN Buffer and Interlayer
Authors: Öztürk M. K. , Altuntaş H. , Çörekçi S. , Hongbo Y. , Özçelik S. , Özbay E.
Published: June 2010

Abstract: The strain–stress analysis of AlxGa1−xN/GaN (x = 0.3) heterostructures with and without a high‐temperature HT‐AlN interlayer (IL) grown on sapphire (Al2O3) substrates and AlN buffer/Al2O3templates via metal organic chemical vapour deposition (MOCVD) was carried out based on the precise measurement of the lattice parameters by using high‐resolution X‐ray diffraction (HRXRD). Thea‐ andc‐lattice parameters were measured from the peak positions that were obtained by rocking the theta axis at the vicinity of the symmetric and asymmetric plane reflection angles, followed by the in‐plane and out‐of‐plane strains. Then, the biaxial and hydrostatic components were extracted from the total strain values that were obtained and were then discussed in the present study as the effect of the HT‐AlN buffer and IL. The AlN buffer layer (BL) affects the strain values of the AlGaN ternary layer (TL). A further effect was realized by inserting an AlN IL between GaN BL and AlGaN TL. However, the experimental results also show that an AlN IL changes the strain behaviour in thea‐ andc‐directions of the AlGaN TL from the tensile to compressive and the compressive to tensile type, respectively. These similar behaviours were observed in hydrostatic strain, biaxial strain and stress. Their reasons are explained with an effectivea‐lattice parameter, post‐growth cooling and lattice and thermal mismatches.
Confirmation of Principal Residual Stress Directions in Rectilinear Components by Neutron Diffraction
Authors: Robinson J. S. , Hughes D. J. , Truman C. E.
Published: June 2010

Abstract:  Large magnitude residual stresses in precipitation hardened aluminium alloys are a consequence of inhomogeneous plastic deformation arising from thermal strains. Thermal gradients develop because of the metallurgical requirement to quench the material rapidly from the solution treatment temperature. Characterisation of the resulting residual stresses can be usefully performed by neutron diffraction. For rectilinear shapes, it is usually assumed that the orthogonal directions of the sample are coincident with the principal stress directions. To test this assumption, residual strains were measured in a rectilinear block of the aluminium alloy 7449 using the SALSA neutron strain analyser. The strains at a single point in the forging were measured as a function of orientation; that is the forging was rotated around the three orthogonal axes of a coordinate system with its origin at the measurement point. Analysis of the neutron diffraction data allowed the determination of the full three‐dimensional strain and stress tensors which confirmed that the orthogonal directions of the forging did coincide with the principal stress directions.
ON THE ROBUSTNESS OF RANGE‐BASED VOLATILITY ESTIMATORS
Authors: Akay Ozgur (Ozzy) , Griffiths Mark D. , Winters Drew B.
Published: June 2010

We empirically examine Parkinson's range‐based volatility estimate in the federal funds market, which is unique because institutional regulations create a predictable pattern in interday volatility. We find that range‐based volatility estimates and standard deviations produce the expected volatility pattern. We also find that at trading pressure points where microstructure noise should be greatest, range‐based estimates are less than the standard deviations. Thus, we support the argument that range‐based volatility estimates remove the upward bias created by microstructure noise. We find that the Parkinson method is the most efficient range‐based volatility measure among a set of alternates in this market.
Leg Symptom Categories and Rates of Mobility Decline in Peripheral Arterial Disease
Authors: McDermott Mary M. , Ferrucci Luigi , Liu Kiang , Guralnik Jack M. , Tian Lu , Liao Yihua , Criqui Michael H.
Published: June 2010

OBJECTIVES: To determine whether asymptomatic lower extremity peripheral arterial disease (PAD) and leg symptoms other than intermittent claudication (IC) in PAD are associated with faster functional decline than in people with both PAD and IC.

DESIGN: Prospective, observational study.

SETTING: Chicago‐area medical center.

PARTICIPANTS: Four hundred fifteen people with PAD followed annually for up to 7 years.

MEASUREMENTS: At baseline, patients with PAD were categorized into symptom categories, including IC; leg pain on exertion and rest; participants who could walk through exertional leg pain (pain/carry on); and participants who never experienced exertional leg pain, even during the 6‐minute walk (always asymptomatic). Outcomes included mobility loss (becoming unable to walk one‐quarter of a mile or walk up and down one flight of stairs without assistance) and becoming unable to complete the 6‐minute walk without stopping. Analyses adjusted for age, sex, comorbidities, ankle brachial index, and other confounders.

RESULTS: Always‐asymptomatic participants (hazard ratio (HR)=2.94, 95% confidence interval (CI)=1.39–6.19, P=.005) and those with leg pain on exertion and rest (HR=2.89, 95% CI=1.47–5.68, P=.002) had greater mobility loss than participants with IC. Participants with PAD with leg pain/carry on were less likely (P=.047) to become unable to walk for 6 minutes continuously without stopping than participants with IC.

CONCLUSION: The ABI identifies patients with asymptomatic PAD and those with atypical leg symptoms who are at risk for greater mobility decline than participants without PAD and participants with PAD with IC.
Testing for Cointegration between House Prices and Economic Fundamentals
Authors: Zhou Jian
Published: June 2010

Economic theory predicts three possibilities for the cointegration relationship between house prices and economic fundamentals: linear cointegration, nonlinear cointegration and no cointegration. In contrast, the empirical literature has only examined linear cointegration. This article argues that ignoring nonlinear cointegration may lead to misleading conclusions that no cointegration exists between house prices and the fundamentals. To illustrate this point, I test for cointegration for ten U.S. cities and find that only one city shows evidence of linear cointegration. Further analysis using the two‐step testing procedure yields evidence of nonlinear cointegration for six other cities. Still, there are three cities left out without evidence of nonlinear cointegration. Further studies are needed to test for other forms of nonlinear cointegration before a conclusion of no cointegration can be reached for the remaining three cities.
Modeling fertilizer externalities around Palo Verde National Park, Costa Rica
Authors: Arriagada Rodrigo A. , Sills Erin O. , Pattanayak Subhrendu K. , Cubbage Frederick W. , González Eugenio
Published: June 2010

Irrigated rice farming in Costa Rica involves use of agrochemicals that pollute important wetlands ecosystems, such as the Palo Verde National Park in the northeastern province of Guanacaste. We characterize rice farming in this region, apply duality theory to estimate conditional factor demand for fertilizer, and then simulate the impacts of alternative policies on fertilizer use. Using a normalized profit function, we also estimate policy impacts on farmer profits. As expected, prices of rice seeds and fertilizer significantly affect use of fertilizer. Price incentives or taxes could encourage farming practices that reduce the threat to downstream ecosystems.
Twist is inversely associated with claudins in germ cell tumors of the testis
Authors: VÄRE PÄIVI , SOINI YLERMI
Published: June 2010

Väre P, Soini Y. Twist is inversely associated with claudins in germ cell tumors of the testis. APMIS 2010; 118: 640–7.

We investigated the expression of claudins 1, 3–7 and transcriptional factor twist in a set of testicular germ cell tumors. The material consisted of 17 seminomas, 13 teratomas, 9 teratocarcinomas, 20 embryonal carcinomas and 9 mixed germ cell tumors. They were immunostained with antibodies to claudins 1, 3–7 and twist. As expected, all claudins were variably present in germ cell tumors with epithelial elements or differentiation, but the intensity of expression varied depending on the claudin type. Mesenchymal elements in teratomatous tumors remained negative for claudins. Expression of different claudins was less intense and inconsistent in other types of germ cell tumors. Choriocarcinomatous elements in germ cell tumors expressed relatively strongly claudin 4 and weaker positivity for claudins 5–7, while claudins 1 and 3 were negative. Seminomas showed expression only for claudins 5 and 7. The transcriptional factor twist was most strongly expressed in seminoma followed by embryonal carcinoma. Twist expression was inversely associated with several claudins (claudins 1, 3, 4 and 6). Germ cell tumors vary in their expression of claudins 1–7. Twist expression was inversely associated with several claudins, suggesting that it takes part in the downregulation of claudins in testicular tumors.
Medical device related pressure ulcers in hospitalized patients
Authors: Black Joyce M , Cuddigan Janet E , Walko Maralyn A , Didier L Alan , Lander Maria J , Kelpe Maureen R
Published: June 2010

Most pressure ulcers occur over bony prominences such as heels and the sacrum. However, the National Pressure Ulcer Advisory Panel recognises that pressure ulcers can also occur on any tissue under pressure and thereby can develop beneath medical devices. This article reports on results from a secondary analysis of existing data collected by The Nebraska Medical Center on pressure ulcer quality improvement initiatives and outcomes. The purpose of this study was to quantify the extent of the problem and identify risk factors for medical device related (MDR) pressure ulcer development in hospitalised patients. A subset of data collected during eight quarterly pressure ulcer incidence and prevalence studies (N = 2178) was created and analysed. The overall rate of hospital‐acquired pressure ulcers was 5·4% (113 of 2079). The proportion of patients with hospital‐acquired ulcers related to medical devices was 34·5% (39 of 113). Findings indicate that if a patient had a medical device, they were 2·4 times more likely to develop a pressure ulcer of any kind. Numerous risk factors for pressure ulcer development were identified; however, none differentiated between those with MDR and traditional pressure ulcers.
Can High School Achievement Tests Serve to Select College Students?
Authors: Cimetta Adriana D. , D'Agostino Jerome V. , Levin Joel R.
Published: June 2010

Postsecondary schools have traditionally relied on admissions tests such as the SAT
and ACT to select students. With high school achievement assessments in place in many states, it is important to ascertain whether scores from those exams can either supplement or supplant conventional admissions tests. In this study we examined whether the Arizona Instrument to Measure Standards (AIMS) high school tests could serve as a useful predictor of college performance. Stepwise regression analyses with a predetermined order of variable entry revealed that AIMS generally did not account for additional performance variation when added to high school grade‐point average (HSGPA) and SAT. However, in a cohort of students that took the test for graduation purposes, AIMS did account for about the same proportion of variance as SAT when added to a model that included HSGPA. The predictive value of both SAT and AIMS was generally the same for Caucasian, Hispanic, and Asian American students. The ramifications of universities using high school achievement exams as predictors of college success, in addition to or in lieu of traditional measures, are discussed.
Application of Think Aloud Protocols for Examining and Confirming Sources of Differential Item Functioning Identified by Expert Reviews
Authors: Ercikan Kadriye , Arim Rubab , Law Danielle , Domene Jose , Gagnon France , Lacroix Serge
Published: June 2010

This paper demonstrates and discusses the use of think aloud protocols (TAPs) as an approach for examining and confirming sources of differential item functioning(DIF). The TAPs are used to investigate to what extent surface characteristics of the items that are identified by expert reviews as sources of DIF are supported by empirical evidence from examinee thinking processes in the English and French versions of a Canadian national assessment. In this research, the TAPs confirmed sources of DIF identified by expert reviews for 10 out of 20 DIF items. The moderate agreement between TAPs and expert reviews indicates that evidence from expert reviews cannot be considered sufficient in deciding whether DIF items are biased and such judgments need to include evidence from examinee thinking processes.
EFFECTS OF HIGH PRESSURE PROCESSING ON SOYBEAN BETA‐CONGLYCININ
Authors: ZHANG HONGKANG , LI LITE , MITTAL G.S.
Published: June 2010

Effects of high pressure processing on conformational changes of soybean β‐conglycinin was studied by means of sulfhydryl groups detection, spectrofluorimetry, ultraviolet difference spectra, circular dichroism and electrophoresis. Significantly more sulflhydryl groups as well as hydrophobic regions and amino acid residues, which had ultraviolet absorbance had been found after high pressure processing (≥300 MPa). The CD analysis indicated that some of the ordered structures ofα‐helix andβ‐structure were destroyed and converted to random coil after processing at 500 MPa for 10 min. Electrophoresis analysis revealed that β‐conglycinin could be denatured and might be dissociated into subunits after high pressure processing (≥300 MPa).

PRACTICAL APPLICATIONS

The use of high pressure for food processing is now getting an increasing interest in the food industry because of the consumer's demand for convenience foods of the highest quality in terms of natural flavor and taste, and which are free from additives and preservatives. It is a possible alternative to temperature treatment. Soybean proteins play an important role in food consumption worldwide. The objectives of this study were to reveal the conformational changes of soybean β‐conglycinin after high pressure processing. The results will help the application of high pressure technology in soybean protein processing.
Dynamic Cardiovascular Risk Assessment in Elderly People
Authors: Harris Scott , Tepper David , Ip Randy
Published: June 2010

Abstract.  Objectives. This study sought to determine whether serial measurement of N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) in com‐munity‐dwelling elderly people would provide additional prognostic information to that from traditional risk factors.

Background. Accurate cardiovascular risk stratification is challenging in elderly people.

Methods. NT‐proBNP was measured at baseline and 2 to 3 years later in 2975 community‐dwelling older adults free of heart failure in the longitudinal Cardiovascular Health Study (CHS). This investigation examined the risk of new‐onset heart failure (HF) and death from cardiovascular causes associated with baseline NT‐proBNP and changes in NT‐proBNP levels, adjusting for potential confounders.

Results. NT‐proBNP levels in the highest quintile (>267.7 pg/mL) were independently associated with greater risks of HF (hazard ratio [HR], 3.05; 95% confidence interval [CI], 2.46–3.78) and cardiovascular death (HR, 3.02; 95% CI, 2.36–3.86) compared with the lowest quintile (<47.5 pg/mL). The inflection point for elevated risk occurred at NT‐proBNP 190 pg/mL. Among participants with initially low NT‐proBNP (<190 pg/mL), those with a >25% increase on follow‐up to >190 pg/mL (21%) were at greater adjusted risk for HF (HR, 2.13; 95% CI, 1.68–2.71) and cardiovascular death (HR, 1.91; 95% CI, 1.43–2.53) compared with those with sustained low levels. Among participants with initially high NT‐proBNP, those with a >25% increase (40%) were at higher risk for HF (HR, 2.06; 95% CI, 1.56–2.72) and cardiovascular death (HR, 1.88; 95% CI, 1.37–2.57), whereas those with a >25% decrease to ≤190 pg/mL (15%) were at lower risk for HF (HR, 0.58; 95% CI, 0.36–0.93) and cardiovascular death (HR, 0.57; 95% CI, 0.32–1.01) compared with those with unchanged high values.

Conclusions. NT‐proBNP levels independently predict HF and cardiovascular death in older adults. NT‐proBNP levels frequently change over time, and these fluctuations reflect dynamic changes in cardiovascular risk.

deFilippi CR, Christenson RH, Gottdiener JS, et al. Dynamic cardiovascular risk assessment in elderly people. The role of repeated N‐terminal pro‐B‐type natriuretic testing. J Am Coll Cardiol. 2010; 55: 441‐450.
Sources of Suspended‐Sediment Flux in Streams of the Chesapeake Bay Watershed: A Regional Application of the SPARROW Model1
Authors: Brakebill John W. , Ator Scott W. , Schwarz Gregory E.
Published: June 2010

Brakebill, John W., Scott W. Ator, and Gregory E. Schwarz, 2010. Sources of Suspended‐Sediment Flux in Streams of the Chesapeake Bay Watershed: A Regional Application of the SPARROW Model. Journal of the American Water Resources Association (JAWRA) 46(4): 757‐776. DOI: 10.1111/j.1752‐1688.2010.00450.x

Abstract:  We describe the sources and transport of fluvial suspended sediment in nontidal streams of the Chesapeake Bay watershed and vicinity. We applied SPAtially Referenced Regressions on Watershed attributes, which spatially correlates estimated mean annual flux of suspended sediment in nontidal streams with sources of suspended sediment and transport factors. According to our model, urban development generates on average the greatest amount of suspended sediment per unit area (3,928 Mg/km2/year), although agriculture is much more widespread and is the greatest overall source of suspended sediment (57 Mg/km2/year). Factors affecting sediment transport from uplands to streams include mean basin slope, reservoirs, physiography, and soil permeability. On average, 59% of upland suspended sediment generated is temporarily stored along large rivers draining the Coastal Plain or in reservoirs throughout the watershed. Applying erosion and sediment controls from agriculture and urban development in areas of the northern Piedmont close to the upper Bay, where the combined effects of watershed characteristics on sediment transport have the greatest influence may be most helpful in mitigating sedimentation in the bay and its tributaries. Stream restoration efforts addressing floodplain and bank stabilization and incision may be more effective in smaller, headwater streams outside of the Coastal Plain.
Radiation‐inducible human tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) gene therapy: a novel treatment for radioresistant uveal melanoma
Authors: Zhou Yixiong , Song Xin , Jia Renbin , Wang Haibo , Dai Liyan , Xu Xiaofang , Gu Ping , Ge Shengfang , Fan Xianqun
Published: June 2010

Uveal melanoma (UM) is one of the most therapy‐resistant cancers. Radiotherapy is the preferred treatment for most cases of UM. However, some UM cells, such as the SP6.5 or OM431 cell lines, are relatively radioresistant. In this study, we attempted to improve the current UM therapy using an adenovirus radio‐inducible gene therapy system. The antitumor adenovirus was constructed by inclusion of the radiation‐inducible early growth response gene 1 (EGR1) promoter and the anticancer tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) gene. We demonstrated that the UM SP6.5 and OM431 cell lines were susceptible to the TRAIL‐induced antitumor effect. TRAIL expression was enhanced in the adenovirus containing EGR1/TRAIL (Ad‐ET) treatment group by radiotherapy, whereas Ad‐ET significantly increased cell death and apoptosis caused by radiotherapy. In mice bearing xenograft tumors, apoptotic cells were detected in pathological tumor sections. Adenovirus Ad‐ET combined with radiation therapy significantly inhibited tumor growth compared with the other treatment groups (P < 0.01). Our findings indicate that radioresponsive gene therapy has the potential to be a more effective and specific therapy for UM because the therapeutic gene can be spatially or temporally controlled by exogenous radiation.
Advances in Cardiac Pacing: Beyond the Transvenous Right Ventricular Apical Lead
Authors: Kapa Suraj , Bruce Charles J. , Friedman Paul A , Asirvatham Samuel J.
Published: June 2010

While for decades right ventricular (RV) apical pacing has been the standard of care for patients requiring pacemaker or defibrillator lead placement, investigators have sought alternatives to achieve more physiologic electrical activation of the heart and reduce long‐term pathologic effects of nonphysiologic apical pacing. These investigations have included attempts at identifying superior pacing sites within the right atrium and RV and development of new leads to enhance specificity of sensing and capture. This review focuses on recent advances in alternative sites for pacing and developments in novel pacing technology ranging from intramyocardial electrodes to leadless pacemakers. First, there have been several studies demonstrating potential benefits of site‐specific pacing, including His bundle pacing and RV outflow tract pacing in potentially attenuating electromechanical dyssynchrony and long‐term functional decline seen with RV apical pacing. Available options for lead placement have been enhanced by development of intramyocardial electrodes that may significantly reduce far‐field oversensing and nonchamber specific capture. With development of intramyocardial electrodes, the potential for atrioventricular septal pacing has recently been described, making synchronous activation of both ventricles with a one‐lead system possible without crossing the tricuspid valve and offering an alternative to modern cardiac resynchronization therapy (CRT). Finally, recent advances in leadless pacemaker systems using ultrasound or magnetic fields are briefly discussed. The results of these studies suggest that there may be options to the RV apex, made possible by novel lead and pacemaker technology. These advances can potentially aid in reducing long‐term negative effects of chronic pacemaker therapy.
Prehypertension: the Rationale for Early Drug Therapy
Authors: Fuchs Flávio Danni
Published: June 2010

Blood pressure within prehypertensive levels confers higher cardiovascular risk by two means. At first, these levels are associated with higher risk for cardiovascular events, starting at BP values as low as 115/75 mmHg, and doubling at each 20 mmHg for systolic or 10 mmHg for diastolic BP. Prehypertension is also an intermediate stage for full hypertension, which develops in an annual rate of 7 out 100 individuals with 40–50 years of age. The precocious drug intervention in patients with prehypertension is therefore appealing. In individuals with previous cardiovascular disease or diabetes the use of BP‐lowering agents is compulsory, since the 18–42% reduction of major cardiovascular events demonstrated in randomized clinical trials translates in palpable clinical benefit. In the absence of higher baseline risk, the absolute benefit of treatment is presumably small and was not demonstrated to date. These individuals could be candidate to treatment with the aim to prevent the development of full hypertension. The long‐lasting effectiveness of non‐drug therapies is low outside the controlled conditions of randomized clinical trials, and there are evidences that the use of BP‐lowering drugs reduces the incidence of hypertension in individuals with prehypertension by more than 60%. Clinical trials testing the efficacy and safety of BP agents to prevent hypertension in a population‐based perspective are required. In the meantime, it is worthy to present the option to start low doses of BP agents for individuals with prehypertension without co‐morbidities who do not respond to the prescription of lifestyle modification.
Oxidative Stress Impairs Endothelial Function in Nondipper Hypertensive Patients
Authors: Maio Raffaele , Perticone Maria , Sciacqua Angela , Tassone Eliezer J. , Naccarato Paola , Bagnato Chiara , Iannopollo Gianmarco , Sesti Giorgio , Perticone Francesco
Published: June 2010

Aims: Essential hypertension, as well as other established cardiovascular risk factors, is associated with endothelial dysfunction. Hypertensive patients with a nondipper circadian pattern have a greater risk of cerebrovascular and cardiovascular complications in comparison with those with a dipper circadian pattern. In this study, we evaluated the association between nondipper pattern and endothelial function in patients with essential hypertension. Methods: We evaluated the forearm blood flow (FBF) response to intraarterial acetylcholine (ACh), an endothelium‐dependent vasodilator, and sodium nitroprusside (SNP), an endothelium‐independent vasodilator, infusions in 190 hypertensive patients stratified according to dipper and nondipper status. The FBF was measured by strain‐gauge plethysmography. Effects of oxidative stress on FBF were evaluated by intraarterial infusion of vitamin C. Ambulatory BP monitorings were obtained by a validated oscillometric device (SpaceLabs 90207 Monitor Inc., Issaquah, WA, USA). Results: Systolic and diastolic blood pressures were higher during daytime and lower during night‐time in dipper subjects than in nondippers. The peak percent increase in ACh‐stimulated FBF was higher in dippers than in nondippers (473% vs. 228%, P < 0.001). The FBF responses to SNP were similar in dipper and nondipper patients. The FBF response to ACh during coinfusion of vitamin C was higher in nondippers rather than in dipper hypertensives. Conclusions: Present data demonstrate that endothelium‐dependent vasodilation is impaired in patients who have nondipper hypertension. The effects of vitamin C on impaired ACh‐stimulated vasodilation support the hypothesis that oxidative stress contributes to endothelial dysfunction of nondipper hypertensive patients.
Role of Zolpidem in the Management of Insomnia
Authors: Dang Amit , Garg Amit , Rataboli Padmanabh V.
Published: June 2010

Insomnia is a common condition that affects one's ability to sleep comfortably and consequently to work effectively. Its etiology is multifactorial and involves plethora of risk factors. Consequences can vary from mild sleepiness to more sever psychiatric disturbances and ischemic stroke. Despite several diagnostic criteria it is poorly diagnosed and less often treated. Benzodiazepines formed the mainline therapy for many years till the advent of newer nonbenzodiazepine group of drugs including zolpidem. Zolpidem is an imidazo‐pyridine compound that enhances the GABAAreceptor function by interaction with Omega‐1 receptor subtype. Its pharmacokinetic profile allows the patients to use it later in the night when having trouble falling asleep without any residual cognitive impairment the next morning. It has rapid onset of action, improves total sleep duration, and reduces night‐time awakenings. Its adverse effect profile is satisfactory as it appears to have low addiction potential. This review will focus on the current role of zolpidem in the management of insomnia.
REVIEW: An Approach for Neuroprotective Therapies of Secondary Brain Damage after Excitotoxic Retinal Injury in Mice
Authors: Ito Yasushi , Shimazawa Masamitsu , Hara Hideaki
Published: June 2010

Background: Many current therapeutic strategies for several eye diseases, such as glaucoma, retinal ischemia, and optic neuropathy, are focused on protection of the retinal ganglion cells (RGCs). In fact, loss of visual field, including irreversible blindness, is caused by RGC damage in these diseases. However, recent evidence suggests that the RGC damage extends to visual center in brain: the visual impairment induced by these diseases may result not only from RGC loss, but also from neuronal degeneration within the visual center in brain. Objective: To protect neurons within the visual center in the brain, as well as retinal treatment, for the prevention of visual disorder in these diseases. Methods: Once considered difficult to study the visual center in brain following RGCs loss, because obtaining the human samples that are suitable for the study may be difficult. In addition, the monkey, mainly used as glaucomatous model, is relatively high cost and needs to long experiment‐span. Here, we focused on mice, because of their high degree of availability, relatively low cost, and amenability to experimental and genetic manipulation. Conclusion: In this review, we describe time‐dependent alterations in the visual center in brain following RGCs loss, and whether some drugs prevent the neuronal damage of the visual center in the brain.
Seroprevalence and Risk Factors forToxoplasma gondiiInfection on Finishing Swine Reared in the Umbria Region, Central Italy
Authors: Veronesi F. , Ranucci D. , Branciari R. , Miraglia D. , Mammoli R. , Fioretti D. P.
Published: June 2010

Toxoplasma gondiiis a worldwide zoonotic protozoan parasite and pork is considered the major meat source ofToxoplasmainfection in humans. To determine the prevalence of infection ofToxoplasma gondiiin pigs reared in the Umbria Region (Central Italy), blood samples of 960 pigs from 10 different farms (96 for each farm) were randomly collected and tested for antibodies (IgG) againstT. gondiiusing an IFA assay. Sera were screened at 1/16 titrr and the endpoint titre was determined. Farm management questionnaires were completed and used to develop descriptive statistics on the tested farms as well as to determine measures of association for risk factors for the presence ofT. gondii‐seropositive pigs. A total of 155 seropositive pigs (16.14%) were identified; within herds prevalence ranged from 8.33 to 25%. The statistical analysis identified all‐in‐all‐out housing and cleaning method as risk factors forToxoplasmainfection.
Effect of two feeds and submaximal exercise on plasma norepinephrine and epinephrine
Authors: GABBARD MARIE L. , WICKLER S. J. , COGGER E. A. , STIFFLER D.
Published: June 2010

4 Arabian horses were used in a randomised, repeated measure design to examine plasma norepinephrine and epinephrine responses to 2 common feeds and subsequent exercise. On each of 4 sampling periods, 2 horses were fed one of 2 isoenergetic meals, either 100% corn or 100% alfalfa, at 22% of their estimated daily energy requirement. Two hours after the meal, each horse was exercised submaximally in 3 consecutive 10 min runs of increasing intensity. Mean ± s.e. heart rates were 132 ± 2, 140 ± 1 and 147 ± 2 beats/min, respectively. Norepinephrine values (nmol/l) were higher in resting horses fed alfalfa (mean ± s.e. 1.98 ± 0.25) than in those fed corn. Epinephrine values were not different between diets (4.48 ± 1.00 alfalfa and 3.86 ± 0.84 corn). During exercise, norepinephrine increased from 2.00 ± 0.45 to 3.24 ± 0.74 for alfalfa and from 0.80 ± 0.17 to 1.79 ± 0.29 for corn fed horses. There was a significant effect of meal with norepinephrine values being higher on alfalfa than on corn. During exercise, epinephrine levels did not change and there was no effect of feed type. These results indicate that a single high soluble carbohydrate meal, fed at 22% of NRC estimates, did not increase sympathetic activity during submaximal exercise.
Climatic energy demand of horses
Authors: MORGAN EMMA KARIN M.
Published: June 2010

The objective of this study was to determine the climatic energy demand i.e. the non‐evaporative heat loss expressed in watts per square metre (W/m2) of horses at low temperatures. Five horses were used; 4 Standardbred trotters and 1 Shetland pony stallion. The horses were fed for maintenance and light work and housed in a warm environment (15–20°C). Measurements were made in a climate chamber at 6 different temperatures; ‐3, 6, 15, 20, 30 and 37°C. Each horse was in the climate chamber for 1.5 h on each occasion. The measuring period was 1 h. A hygrometric tent inside the climate chamber was used to measure evaporative heat loss. Ambient air temperature, radiant temperature, deep body temperature, skin and coat temperatures were measured and, together with cutaneous evaporative heat loss, used to calculate the non‐evaporative heat loss. The lower critical temperature (LCT) was estimated for each horse in the study. The average LCT of horses acclimatised to an indoor temperature of 15–29°C was 18.2°C. At LCT the average total heat loss was 127 W/m2. The corresponding partitioned heat loss was 96 W/m2 non‐evaporative and 31 W/m2 evaporative. The results show an average maximal tissue thermal resistance of 0.076 K·m2/W and an average thermal resistance of the coat of 0.087 K·m2/W. The climatic energy demand for these horses was 3 W/m2·°C for temperatures below LCT in dry and calm conditions. For a 500 kg horse this additional energy requirement could be met by an extra 0.15 kg hay/°C below LCT. Smaller and lighter weight horses need relatively more feed in cold conditions.
Physiological responses of donkeys to treadmill exercise and conditioning: a pilot study
Authors: FOSTER ERICA L. , MATTHEWS NORA S. , TAYLOR T. S. , POTTER G. D. , WELFARE R. E. , ERICKSON S. W. , WILLIAMS J. D.
Published: June 2010

Five healthy standard donkeys were subjected to exercise tests on a treadmill before and after conditioning. After the pre‐conditioning trial, the donkeys worked 3 days/week for 60 min pulling a cart at increasing trot duration and 2 days/week for 20 min in a round pen for the 28 day conditioning period. During the trial, donkeys worked at 1.5–2 m/s on an 11% grade for a distance of 1830 m. Heart rate, respiratory rate and body temperature were recorded before, 10 min into exercise, immediately following and 1, 5, 10, 20, 30, and 60 min after exercise. Arterial samples for blood gas measurements and venous samples for measurement of lactate [La−], glucose and triglyceride concentrations also were collected.

Mean blood [La−] in unconditioned donkeys increased from 1.25 mmol/l at rest to 3.48 mmol/l at 1 min after exercise. Conditioning resulted in decreased heart rate and lactate and blood glucose concentrations during recovery. There were no effects of exercise or conditioning on triglyceride concentrations or blood gas values.
Kinematics of blood lactate concentration during an incremental treadmill test in saddle horses
Authors: GALLOUX P. , BARREY E. , AUVINET B. , VALETTE J. P. , WOLTER R.
Published: June 2010

The purpose of this study was to investigate the kinetics of blood lactate concentration in 5 saddle horses during an incremental test on an inclined treadmill (3%). In order to mimic field conditions, the exercise test consisted of five 3 min bouts at increasing speeds (7.5, 8.3, 9.2 and 10 m/s); each bout being followed by 1 min rest. Blood samples were taken prior to each step, every minute during each step and every 30 s during each rest period. At low intensities of exercise, stability of blood lactate concentration was sometimes observed during the first minutes of the bout, followed by an increase in the second part. At higher intensities, blood lactate concentration rose more quickly and no stability was observed. Lactate concentration in the blood sample taken at t3′30 during the rest period, often reached a higher value than in the preceeding bout. The VLa4 calculated from blood lactate concentrations obtained at t3′ and t3′30 were not significantly different (P>0.05); mean ± s.d. 9.8 ± 0.7 and 9.8 ± 0.6 m/s, respectively. By using the blood lactate concentrations obtained at t4', the VLa4 appeared higher (mean ± s.d. 10.1 ±0.7 m/s).
Blood gas changes during incremental and sprint exercise
Authors: CHRISTLEY R. M. , EVANS D. L. , HODGSON D. R. , ROSE R. J.
Published: June 2010

We investigated and compared arterial blood gas and ventilatory changes during rapid acceleration sprint and during incremental treadmill exercise. Seven clinically normal racehorses completed standardised incremental exercise tests and rapid acceleration tests at speeds calculated to elicit 115% V̇o2max. Arterial oxygen tension decreased (P<.001) between 15 s (mean ± s.d. 103.8 ± 14.3 mmHg) and 30 s (85.0 ± 7.7 mmHg) after the onset of rapid acceleration exercise, but did not change significantly during the remainder of the sprint. This was accompanied by an increase in Paco2 of 5.9 mmHg (P<.05). Despite reductions in Sao2 during exercise, Cao2 did not change due to increases in haemoglobin concentration. Heart rate increased rapidly (P<.001) during the first 15 s of exercise and thereafter remained constant. The mean maximum speed during the incremental test (11.4 ± 0.5m/s) was not significantly different to the speed calculated to elicit 115% V̇o2max during the sprint test (12.2 ± 0.8 m/s). The mean peak HR and Hb during the sprint test were significantly less than during the incremental test. However, there were no significant differences in the maximum or minimum values achieved for other variables.

We conclude that rapid acceleration exercise is accompanied by rapid changes in blood gas variables, reaching steady state within 45 s. Blood gas responses during the simpler incremental test describe maximal changes during high‐intensity sprint exercise.
High‐altitude effects on respiratory gases, acid‐base balance and pulmonary artery pressures in equids
Authors: GREENE HOLLY M. , WICKLER S. J. , ANDERSON T. P. , COGGER E. A. , LEWIS C. C. , WYLE A.
Published: June 2010

Arterial and venous blood were analysed at rest and post exercise for pH, Pco2, and Po2, and bicarbonate ([HCO3−]), base excess (BE), and strong ion difference (SID) were calculated in response to a 10 day sojourn to 3800 m. Pulmonary artery pressures (PAP) were measured at rest Post exercise samples were restricted to venous blood. The equids (n = 6) experienced a profound hypoxia‐hypocapnia and a respiratory alkalosis. Pao2 decreased 42% and Paco2 41%. Paco2 increased to 80% of initial values after 8 days at altitude. Arterial [HCO3−] decreased by 34%; however, it returned to normal by Day 4. Base excess decreased initially, but increased at altitude with time. Strong ion difference was decreased during the altitude exposure and continued to be depressed even after return to low altitude. Pulmonary artery pressure increased 63% on Day 1 of exposure (from 27.9 ± 2 to 45.4 ± 3 mmHg); Days 2 and 6 averaged 36.3 ± 3 and 37.5 ± 3 mmHg. Thirty‐six hours after return to 225 m, most variables (except [SID] and post exercise BE) returned to normal. The most profound changes in the indicators of gas exchange, at altitude, occurred during the first 3 days and only [HCO3−] returned to normal during the subsequent acclimatisation to altitude.
Comparison of exercise variables measured during intensity of simulated training to variables at maximal effort in Standardbreds
Authors: PRINGLE J. , MacMILLAN K. , BRIAND H. , STäMPFLI H.
Published: June 2010

The heart rate changes during routine training in a group of 8 actively racing Standardbreds were used to simulate the training work on a treadmill (ST) and indices of exercise compared to maximal effort (MAX) on the treadmill. The following parameters were recorded during treadmill work: heart rate, velocity, O2 consumption, respiratory and stride frequency, and stride length. Blood lactate concentrations were measured before and after each work test.

Heart rate during simulated training was mean ± s.d. 87.8 ± 5.5% heart rate in MAX, one of the 8 horses working <80% of maximal HR and 2 of the 8 horses working above 90% maximal heart rate. Mean ± s.d. oxygen consumption during the ST was 75.1% ± 8.4% MAX, but correlated poorly against percentage heart rate for individual horses (r2 = 0.02). At similar velocities for the ST and MAX, only respiratory frequency differed significantly (P>0.05), being higher during the ST.

Most horses worked at intensities based on heart rate consistent with proposed guidelines of 80–90% of maximal heart rate. However, in 3 of the 8 horses work intensity of insufficient or excessive amounts may have occurred.
Effects of electrolyte and glycerol supplementation on recovery from endurance exercise
Authors: II H. C. SCHOTT , DüSTERDIECK KATJA F. , EBERHART SUSAN W. , WOODY KRISTINA A. , REFSAL K. R. , COENEN M.
Published: June 2010

Incomplete recovery from endurance exercise after an overnight rest period is reflected by persisting weight loss and an elevated plasma aldosterone concentration, even in successful competitors. To determine whether supplementation with high doses of electrolytes, with or without glycerol, enhances recovery, the following were measured in 6 Arabian horses before and after completion of a 60 km treadmill exercise test simulating an endurance ride and after 12, 24, 48, and 72 h of recovery: bodyweight; plasma osmolality; plasma concentrations of protein, electrolytes, aldosterone and cortisol; and urine and faecal electrolyte concentrations. Before and during the exercise test, horses were supplemented with a total of 2.4 ml/kg bwt of water (W); 0.2 g/kg bwt KCl and 0.4 g/kg bwt NaCl in 2.4 ml/kg bwt of water (E); or 0.2 g/kg bwt KCl and 0.4 g/kg bwt NaCl in 2.4 ml/kg bwt (3 g/kg bwt) of glycerol (GE). Although weight loss after completion of the simulated ride was greater (P<.01) for W (3.2%) than for E and GE (1.0 and 0.9%, respectively), horses supplemented with E or GE experienced further weight loss by 24 h after the simulated ride (2.2 and 2.1% for E and GE, respectively) while body weight with W remained unchanged (3.0%) from the finish value. After 48 h of recovery, bodyweight was not different from the starting values with E and GE but remained decreased (P<.01) with W throughout the recovery period (2.2% persisting weight loss after 72 h of recovery). Plasma osmolality and plasma Na+and Cl−concentrations increased (P<.01) and plasma protein concentration decreased (P<.01) after the exercise test with E and GE but were unchanged with W. Plasma osmolality and protein and electrolyte concentrations returned to pre‐exercise values within 12 h of recovery with the exception of a persistent increase in plasma Na+concentration with GE. The greatest plasma aldosterone concentration was measured after 12 h of recovery with W (1357 pmol/l) and was greater (P<.02) than that with E and GE (24 and 304 pmol/l, respectively). Urine production during the simulated ride increased (P<.01) with GE and resulted in loss of ˜20% and essentially 100% of supplemented Na+and K+, respectively. In contrast, electrolyte losses in faeces were unaffected by electrolyte or glycerol supplementation. In conclusion, supplementation with high doses of electrolytes as hypertonic oral pastes attenuated weight loss during a simulated endurance ride (by enhancing voluntary water intake); however, it did not prevent development of significant weight loss during the initial 24 h of recovery. Glycerol administration resulted in no benefits, and actually increased urine electrolyte losses, in comparison to supplementation with electrolytes alone.
Effect of walking velocity on forelimb kinematics and kinetics
Authors: KHUMSAP S. , CLAYTON H. M. , LANOVAZ J. L. , BOUCHEY M.
Published: June 2010

A database of biomechanical variables obtained from normal horses walking at a range of velocities is needed for comparison with the variables obtained from lame horses in which velocity cannot be predetermined. The objective was to investigate velocity‐dependent changes in selected kinematic variables, ground reaction forces (GRF) and net joint energies in the forelimb and to develop statistical equations to calculate expected values of these variables for horses walking at different velocities. Five sound horses walked at a range of velocities (0.82 to 1.91 m/s) over a force plate. Kinematic data were recorded simultaneously for 51 trials. Kinematic, GRF and energetic variables were determined using standard methods. Correlation and simple regression analyses between velocity and measured variables were performed. An increase in walking velocity was correlated with an increase in stride length and decreases in stride and stance duration. Vertical, braking and propulsive impulses decreased as a consequence of the large reduction in stance duration, even though peak vertical, braking and propulsive GRFs increased. There was no significant increase in energy generation at any of the forelimb joints, indicating that muscle activity was not the source of the increase in GRFs. Changes in the longitudinal GRFs appeared to be influenced by velocity‐dependent increases in head and neck oscillations. The equations obtained in this study can be used to calculate the expected normal variables from a range of walking velocities and to detect deviations from normal values in lame horses.
Evaluation of the force acting on the back of the horse with an English saddle and a side saddle at walk, trot and canter
Authors: WINKELMAYR B. , PEHAM C. , FRÜHWIRTH B. , LICKA T. , SCHEIDL M.
Published: June 2010

Reasons for performing study: Force transmission under an English saddle (ES) at walk, trot and canter is commonly evaluated, but the influence of a side saddle (SS) on the equine back has not been documented.

Hypothesis: Force transmission under a SS, with its asymmetric construction, is different from an ES in walk, trot and canter, expressed in maximum overall force (MOF), force in the quarters of the saddle mat, and centre of pressure (COP). The biomechanics of the equine back are different under a SS compared to ES.

Methods: Thirteen horses without clinical signs of back pain ridden in an indoor riding school with both saddles were measured using an electronic saddle sensor pad. Synchronous kinematic measurements were carried out with tracing markers placed along the back in front of (withers, W) and behind the saddle (4th lumbar vertebra, L4). At least 6 motion cycles at walk, trot and canter with both saddles (ES, SS) were measured. Out of the pressure distribution the maximum overall force (MOF) and the location of the centre of pressure (COP) were calculated.

Results: Under the SS the centre of pressure was located to the right of the median and slightly caudal compared to the COP under the ES in all gaits. The MOF was significantly different (P<0.01) between saddles. At walk, L4 showed significantly larger (P<0.01) vertical excursions under the ES. Under the SS relative horizontal movement of W was significantly reduced (P<0.01) at trot, and at canter the transversal movement was significantly reduced (P<0.01). In both trot and canter, no significant differences in the movement of L4 were documented.

Conclusions and potential relevance: The results demonstrate that the load under a SS creates asymmetric force transmission under the saddle, and also influences back movement. To change the load distribution on the back of horses with potential back pain and as a training variation, a combination of both riding styles is suitable.
Impact of Thermodiffusion on Carbon Nanotube Growth by Chemical Vapor Deposition
Authors: Lysaght Andrew C. , Chiu Wilson K. S.
Published: June 2010

Thermal diffusion, the process by which a multicomponent mixture develops a concentration gradient when exposed to a temperature gradient, has been studied in order to understand if its inclusion is warranted in the modeling of single-wall carbon nanotubes (SWNTs) synthesis by thermal chemical vapor deposition (CVD). A fully coupled reactor-scale model employing conservation of mass, momentum, species, and energy equations with detailed gas phase and surface reaction mechanisms has been utilized to describe the evolution of hydrogen and hydrocarbon feed streams as they undergo transport, as well as homogeneous and heterogeneous chemical reaction within a CVD reactor. Steady state velocity, temperature, and concentration fields within the reactor volume are determined, as well as concentrations of adsorbed species and SWNT growth rates. The effect of thermodiffusion in differing reactor conditions has been investigated to understand the impact on SWNT growth. Thermal diffusion can have a significant impact on SWNT growth, and the first approximation of the thermal diffusion factor, based on the Chapman–Enskog molecular theory, is sufficient for modeling thermophoretic behavior within a CVD reactor. This effect can be facilitatory or inhibitory, based on the thermal and mass flux conditions. The results of this investigation are useful in order to optimize model and reactor designs to promote optimal SWNT deposition rates.