bluuebunny/crossref_metadata_2025 huggingface dataset:
Juvenile–adult tree associations in a continental Mediterranean ecosystem: no evidence for sustained and general facilitation at increased aridity
Authors: Granda Elena , Escudero Adrián , de la Cruz Marcelino , Valladares Fernando
Published: September 2011

Question

How do tree species identity, microhabitat and water availability affect inter‐ and intra‐specific interactions between juvenile and adult woody plants?

Location

Continental Mediterranean forests in Alto Tajo Natural Park, Guadalajara, Spain.

Methods

A total of 2066 juveniles and adults of four co‐occurring tree species were mapped in 17 plots. The frequency of juveniles at different microhabitats and water availability levels was analysed using log‐linear models. We used nearest‐neighbour contingency table analysis of spatial segregation and J‐functions to describe the spatial patterns.

Results

We found a complex spatial pattern that varied according to species identity and microhabitat. Recruitment was more frequent in gaps for Quercus ilex, while the other three species recruited preferentially under shrubs or trees depending on the water availability level. Juveniles were not spatially associated to conspecific adults, experiencing segregation from them in many cases. Spatial associations, both positive and negative, were more common at higher water availability levels.

Conclusions

Our results do not agree with expectations from the stress‐gradient hypothesis, suggesting that positive interactions do not increase in importance with increasing aridity in the study ecosystem. Regeneration patterns are species‐specific and depend on microhabitat characteristics and dispersal strategies. In general, juveniles do not look for conspecific adult protection. This work contributes to the understanding of species co‐existence, proving the importance of considering a multispecies approach at several plots to overcome limitations of simple pair‐wise comparisons in a limited number of sites.
VARIABILITY OF STARCH‐BASED THICKENED DRINKS FOR PATIENTS WITH DYSPHAGIA IN THE HOSPITAL SETTING
Authors: PAYNE CLARE , METHVEN LISA , FAIRFIELD CAROL , GOSNEY MARGOT , BELL ALAN E.
Published: September 2011

Starch‐based thickening agents may be prescribed for patients with dysphagia. Thickened fluids alter variables of the swallow reflex, allowing more time for bolus manipulation without compromising airway closure. This investigation explored the variation in viscosity and physical characteristics of thickened drinks prepared in different media under laboratory conditions and compared the results with those of thickened drinks presented to dysphagic patients in one hospital. The rheological characteristics were tested on a simple plastometer and a Bohlin CVOR rheometer (Malvern Instruments, Worcestershire, UK). Samples prepared to “syrup” consistency both in the laboratory and in the hospital were significantly different from each other (P < 0.0001). This was also the case for samples prepared to “custard” consistency. Differences existed not only in viscosity, but drinks prepared in different media produced different rheological matrices. This signifies different viscoelastic behaviors that may effect manipulation in the mouth. From this study, preparation of thickened drinks using starch‐based instant thickening powders appears to be a highly variable practice.

PRACTICAL APPLICATIONS

The research has highlighted differences in the preparation of thickened drinks for patients with dysphagia among guidelines, descriptors, manufacturers' instruction and actual preparation in the hospital setting. The differences in the final thickness and rheology produced when preparing drinks of different types and temperatures were significant and may have clinical consequences. The results can be used to provide advice and recommendations when preparing drinks in practice.
A note on the triple product property for subsets of finite groups
Authors: Neumann Peter M.
Published: September 2011

The triple product property (TPP) for subsets of a finite group was introduced by Henry Cohn and Christopher Umans in 2003 as a tool for the study of the complexity of matrix multiplication. This note records some consequences of the simple observation that if (S1,S2,S3) is a TPP triple in a finite group G, then so is (dS1a,dS2b,dS3c) for any a,b,c,d∈G.

Let si:=∣Si∣ for 1≤i≤3. First we prove the inequality s1(s2+s3−1)≤∣G∣ and show some of its uses. Then we show (something a little more general than) that if G has an abelian subgroup of index v, then s1s2s3 ≤v2 ∣G∣.
Experimental Study of Vibration Damping in a Modified Elastic Wedge of Power-Law Profile
Authors: Bayod J. Javier
Published: September 2011

The objective of this research is to evaluate and propose a modified elastic wedge as passive damping system for structural damping. An elastic wedge is a plate whose thickness decreases smoothly toward zero. It has been proposed as an effective passive damping system to reduce structural vibration, especially in the high frequency range. Several authors have researched elastic wedge theory and showed that if the thickness of a plate decreases toward zero following a power law function, the flexural waves traveling in that plate do not suffer reflection along their path. That energy accumulates at the zero thickness edge, which results in a very efficient damping. In practice, manufacturing a zero thickness edge is not possible and a large amount of the wave energy is reflected at the thinner edge. However, when a small quantity of damping material is added on that edge, a very effective damping can be achieved. The damping effectiveness of the elastic wedge increases proportionally to the thinness of the edge for a given quantity of the added damping material. However, manufacturing of an elastic wedge with a very thin edge is economically costly since high precision machining is required. This presents a problem for practical implementation into the manufacturing line. In this paper, a modified elastic wedge is proposed to facilitate manufacturing and to reduce cost so that practical implementation is possible. In the proposed modified elastic wedge, the thin edge has a thickness achievable with conventional tools. Then, to increase its damping effectiveness, the thin edge is extended for some length with constant thickness. Finally, damping material is added on the extended part. Experimental and finite element method (FEM) frequency response analyses were carried out with a modified elastic wedge. The results show that the proposed modified elastic wedge can also achieve very effective vibration damping, especially in the high frequency range, while being manufactured with conventional tools. This method is currently under evaluation for noise reduction in structures of large dimensions, like platelike components of ship structures, or other machinery to reduce vibration and noise emission, and where cost and manufacturing accuracy limit the application of the conventional elastic wedge.
Semi Analytical Solution to Transient Start of Weakly Underexpanded Turbulent Jet
Authors: Chitsaz Iman , Saidi Mohammad Hassan , Mozafari Ali Asghar
Published: September 2011

This study presents a semi analytical solution for the transient weakly underexpanded jet. Different polytropic processes are compared with available experimental data in the literature to assess the best process for steady and transient weakly underexpanded jets. The steady state results agree reasonably well with the experimental and analytical data. It is also shown that isentropic process evaluates steady injection better than other processes. Tip penetration of transient results was compared with available data in literature, and no exact agreement for isothermal and isentropic is observed. This appears due to the linearization of equation of state. It is suggested that more accurate linearization with a combination of process should be used for transient injection. Effects of pressure ratio and exit velocity on the pressure profile are shown. It is also concluded that during injection locations of shock cells do not vary with pressure ratios while are affected by exit velocity.
Live Attenuated Malaria Vaccine Designed to Protect Through Hepatic CD8
+
T Cell Immunity
Authors: Epstein J. E. , Tewari K. , Lyke K. E. , Sim B. K. L. , Billingsley P. F. , Laurens M. B. , Gunasekera A. , Chakravarty S. , James E. R. , Sedegah M. , Richman A. , Velmurugan S. , Reyes S. , Li M. , Tucker K. , Ahumada A. , Ruben A. J. , Li T. , Stafford R. , Eappen A. G. , Tamminga C. , Bennett J. W. , Ockenhouse C. F. , Murphy J. R. , Komisar J. , Thomas N. , Loyevsky M. , Birkett A. , Plowe C. V. , Loucq C. , Edelman R. , Richie T. L. , Seder R. A. , Hoffman S. L.
Published: September 2011

The efficacy of a sporozoite-based malaria vaccine is tested in humans, nonhuman primates, and mice.
Predictors of change in sports participation in Latino and non-Latino children
Authors: Corder Kirsten , Crespo Noe C , van Sluijs Esther M F , Sallis James F , Shadron Lisa M , Moody Jamie S , Elder John P
Published: September 2011

Background

Few prospective studies have examined predictors of change in specific physical activity (PA) behaviours in different ethnic groups.

Purpose

To assess predictors of change in sports participation in Latino and non-Latino 5–8 year-old children in San Diego, California.

Methods

Average sports participation frequency (days/week) was assessed by validated parent-report at baseline (Nov 2006–May 2008) and 1 year later in 541 children (45.0% male, 41.1% Latino; mean±SD age: 6.6±0.7 years) taking part in an obesity prevention study (Project MOVE). Biological (sex, age, Body Mass Index z-score), socio-cultural (ethnicity, income, care giver education), parental (PA rules, PA encouragement) and environmental factors (home PA equipment, PA location) were assessed at baseline. Associations between change in sports participation and potential predictors were studied using multilevel linear regression stratified by Latino ethnicity, adjusted for sex, baseline sport participation, study condition and recruitment area.

Results

Sports participation increased over 1 year (mean change: +0.5 days; p<0.001) and change was similar for boys and girls (p=0.95), but Latino children showed a greater increase (p=0.03). The number of locations used for PA (p=0.024) and the total frequency of PA location use (p=0.018) were positively associated with increased sports participation among Latinos. No predictors were identified for non-Latino children.

Conclusions

Only factors relating to PA location were identified as predictors of change in sports participation for Latino children. Interventions targeting specific PA behaviours such as sports participation may need to consider PA locations for Latino children and be tailored for specific ethnic groups.
Suppression of information on the prevalence and prevention of exercise-associated hyponatraemia
Authors: Shephard Roy J
Published: September 2011

It has been suggested recently that financial links between manufacturers of sports drinks and professional Sports Science organisations in North America have suppressed information on the existence and ways of preventing an epidemic of exercise-associated hyponatraemia (EAH). This article reviews evidence for the prevalence of both biochemical and clinical hyponatraemia. It concludes that a limited number of cases of EAH occur after ultra-long distance events, particularly when performed under cold and wet conditions, and that some eight deaths have been associated with EAH since 1985. However, this information has been widely reported, both in North America and in other parts of the world. Claims of an ‘epidemic’ seem unwarranted, and there is no solid evidence supporting the claim that information has been suppressed because of ties between sports scientists and sports drink manufacturers.
A computational model for asynchronous oocyte growth dynamics in a batch-spawning fish
Authors: Li Zhenhong , Villeneuve Daniel L. , Jensen Kathleen M. , Ankley Gerald T. , Watanabe Karen H.
Published: September 2011

A computational model of oocyte growth dynamics (i.e., oocyte recruitment, growth, and spawning) in a batch-spawning fish, fathead minnow (FHM, Pimephales promelas), has been developed. The model provides a quantitative link between oocyte growth dynamics and biochemical processes in FHMs through the absorption of vitellogenin (a lipoprotein precursor of egg yolk proteins) into oocytes, which contributes significantly to oocyte growth in fish. The model simulates the number and volume of oocytes in different batches within a FHM ovary. Model-predicted clutch sizes and spawning intervals matched the experimental data well for both unexposed FHMs and FHMs exposed to 17β-trenbolone (a relatively stable metabolite of trenbolone acetate, a synthetic androgen used as a growth promoter in livestock). Overall, the model presents a novel approach to simulating oocyte growth dynamics in a batch-spawning fish and meets an urgent need in ecotoxicological studies to link the effects of endocrine disrupting chemicals at a biochemical level to adverse effects upon reproduction.
A model for estimating mortality of Atlantic salmon,Salmo salar, between spawning events
Authors: Hubley P. Bradford , Gibson A. Jamie F.
Published: September 2011

We developed a Bayesian hierarchical model to estimate annual mortality of repeat-spawning Atlantic salmon, Salmo salar, that distinguishes between mortality rates and the confounding effects of consecutive-year and alternate-year repeat-spawning strategies. The model provides annual estimates of two mortality rates: mortality in the first year (Z1), a time period during which salmon are primarily in freshwater (staging, spawning, and overwintering) followed by a brief period at sea, and mortality in the second year (Z2) when salmon are predominantly at sea. When fit to data for the LaHave River (Nova Scotia, Canada) salmon population, Z1 showed an increasing trend throughout the time series, whereas Z2 also increased but in a single, stepwise manner. Once a time series of mortality rates was separated from the other life-history parameters, we were able to demonstrate how they could be used for examining the influence of environmental conditions by comparing the estimated mortality rate time series with the North Atlantic Oscillation Index (NAOI). This comparison uncovered a statistically significant correlation between the NAOI and the survival in the second year after spawning that would not have been evident had the mortality estimation model not been developed.
Sockeye salmon (Oncorhynchus nerka) return after an absence of nearly 90 years: a case of reversion to anadromy
Authors: Godbout L. , Wood C.C. , Withler R.E. , Latham S. , Nelson R.J. , Wetzel L. , Barnett-Johnson R. , Grove M.J. , Schmitt A.K. , McKeegan K.D.
Published: September 2011

We document the recent reappearance of anadromous sockeye salmon ( Oncorhynchus nerka ) that were thought to have been extirpated by the construction of hydroelectric dams on the Coquitlam and Alouette rivers in British Columbia, Canada, in 1914 and 1927, respectively. Unexpected downstream migrations of juveniles during experimental water releases into both rivers in 2005 and 2006 preceded upstream return migrations of adults in 2007 and 2008. Genetic (microsatellite and mitochondrial DNA) markers and stable isotope (δ34S and87Sr/86Sr) patterns in otoliths confirm that both the juvenile downstream migrants and adult upstream migrants were progeny of nonanadromous sockeye salmon (kokanee) that inhabit Coquitlam and Alouette reservoirs. Low genetic diversity and evidence of genetic bottlenecks suggest that the kokanee populations in both reservoirs originated from relatively few anadromous individuals that residualized after downstream migration was largely prevented by the construction of dams. Once given an opportunity for upstream and downstream migration, both populations appear capable of reverting to a successful anadromous form, even after 25 generations.
Wingless homolog Wnt11 suppresses bacterial invasion and inflammation in intestinal epithelial cells
Authors: Liu Xingyin , Wu Shaoping , Xia Yinglin , Li Xi Emma , Xia Yuxuan , Zhou Zhongren David , Sun Jun
Published: September 2011

Wnt11 plays an essential role in gastrointestinal epithelial proliferation, and previous investigations have focused on development and immune responses. However, the roles of how enteric bacteria regulate Wnt11 and how Wnt11 modulates the host response to pathogenic bacteria remain unexplored. This study investigated the effects of Salmonella infection on Wnt activation in intestinal epithelial cells. We found that Wnt11 mRNA and protein expression were elevated after Salmonella colonization. Wnt11 protein secretion in epithelial cells was also elevated after bacterial infection. Furthermore, we demonstrated that pathogenic Salmonella regulated Wnt11 expression and localization in vivo. We found a decrease in Salmonella invasion in cells with Wnt11 overexpression compared with cells with normal Wnt11 level. IL-8 mRNA in Wnt11-transfected cells was low; however, it was enhanced in cells with a low level of Wnt11 expression. Functionally, Wnt11 overexpression inhibited Salmonella-induced apoptosis. AvrA is a known bacterial effector protein that stabilizes β-catenin, the downstream regulator of Wnt signaling, and inhibits bacterially induced intestinal inflammation. We observed that Wnt11 expression, secretion, and transcriptional activity were regulated by Salmonella AvrA. Overall, Wnt11 is involved in the protection of the host intestinal cells by blocking the invasion of pathogenic bacteria, suppressing inflammation, and inhibiting apoptosis. Wnt11 is a novel and important contributor to intestinal homeostasis and host defense.
Pretreatment with the probiotic VSL#3 delays transition from inflammation to dysplasia in a rat model of colitis-associated cancer
Authors: Appleyard Caroline B. , Cruz Myrella L. , Isidro Angel A. , Arthur Janelle C. , Jobin Christian , De Simone Claudio
Published: September 2011

Evidence supports involvement of microflora in the transition of chronic inflammation to neoplasia. We investigated the protective efficacy of the probiotic VSL#3 in a model of colitis-associated colorectal cancer. Chronic colitis was induced in Sprague-Dawley rats by administration of trinitrobenzene sulfonic acid (TNBS), followed 6 wk later by systemic reactivation. To induce colitis-associated dysplasia and cancer, the animals received TNBS (intravenously) twice a week for 10 wk. One group received VSL#3 in drinking water from 1 wk before colitis induction until death. The colons were examined for damage and presence of dysplasia or cancer. Samples were analyzed for cell proliferation and apoptosis, vitamin D receptor (VDR) expression, angiogenic factors, and presence of alkaline sphingomyelinase or phosphatase. Microbial community composition was evaluated by terminal restriction fragment-length polymorphism analysis of the bacterial 16S rRNA gene. None of the probiotic-treated animals developed carcinoma, and no high-grade dysplasia was found in either the proximal or mid colon. In contrast, 29% of the animals in the control group developed carcinoma in one or more regions of the colon. VSL#3-treated animals had significantly less damage than the vehicle treated-controls in all areas of the colon, and this correlated with decreased richness and diversity of the mucosally adherent microbiota. Treatment with the probiotic increased the antiangiogenic factor angiostatin, VDR expression, and alkaline sphingomyelinase. We concluded that pretreatment with the probiotic VSL#3 can attenuate various inflammatory-associated parameters, delaying transition to dysplasia and cancer, thus offering its potential therapeutic use in patients with long-standing colitis.
Swimming training improves the vasodilator effect of angiotensin-(1–7) in the aorta of spontaneously hypertensive rat
Authors: Silva Denise M. R. , Gomes-Filho Ary , Olivon Vania C. , Santos Tassia M. S. , Becker Lenice K. , Santos Robson A. S. , Lemos Virginia S.
Published: September 2011

Introduction: endothelial dysfunction plays a critical role in the pathogenesis of hypertension. It is well established that physical training has beneficial effects on the cardiovascular system. We recently reported that angiotensin-(1–7) [Ang-(1–7)] concentration and the Mas receptor expression is increased in the left ventricle of trained spontaneous hypertensive rats (SHR). The vascular effects of Ang-(1–7) in trained animals remain so far unknown. In the present study we investigated the effects of physical training on the vasodilator effect of Ang-(1–7) in the aorta of SHR. Methodology: normotensive Wistar rats and SHR were subjected to an 8-wk period of 5% overload of body weight swimming training. Changes in isometric tension were recorded on myograph. Western blot was used to investigate Ang-(1–7) receptors expression. Results: in aortas from normotensive rats Ang-(1–7) and ACh induced a concentration-dependent vasodilator effect, which was not modified by the physical training. Vessels from SHR had an impaired vasodilator response to Ang-(1–7) and ACh. The swimming training strongly potentiated the vasodilator effect induced by Ang-(1–7) in SHR, but did not modify the effect of ACh. Interestingly, Mas receptor protein expression was substantially increased by physical training in SHR. In trained SHR, the vasodilator effect of Ang-(1–7) was abrogated by removal of the endothelium and by the selective Ang-(1–7) receptor antagonists A-779 and d-Pro7-Ang-(1–7). l-NAME decreased Ang-(1–7) vasodilator response and indomethacin abolished the remaining dilatory response. Conclusion: physical training increased Mas receptors expression in SHR aortas, thereby improving the vasodilator effect of Ang-(1–7) through an endothelium-dependent mechanism involving nitric oxide and prostacyclin.
Characterization of the liver kinase B1-mouse protein-25 -Ste-20-related adaptor protein complex in adult mouse skeletal muscle
Authors: Smith Cody D. , Compton Richard A. , Bowler Joshua S. , Kemp Jonathan T. , Sudweeks Sterling N. , Thomson David M. , Winder William W.
Published: September 2011

In liver, the AMP-activated protein kinase kinase (AMPKK) complex was identified as the association of liver kinase B1 (LKB1), mouse protein 25 (MO25α/β), and Ste-20-related adaptor protein (STRADα/β); however, this complex has yet to be characterized in skeletal muscle. We demonstrate the expression of the LKB1-MO25-STRAD complex in skeletal muscle, confirm the absence of mRNA splice variants, and report the relative mRNA expression levels of these proteins in control and muscle-specific LKB1 knockout (LKB1−/−) mouse muscle. LKB1 detection in untreated control and LKB1−/− muscle lysates revealed two protein bands (50 and 60 kDa), although only the heavier band was diminished in LKB1−/− samples [55 ± 2.5 and 13 ± 1.5 arbitrary units (AU) in control and LKB1−/−, respectively, P < 0.01], suggesting that LKB1 is not represented at 50 kDa, as previously cited. The 60-kDa LKB1 band was further confirmed following purification using polyethylene glycol (43 ± 5 and 8.4 ± 4 AU in control and LKB1−/−, respectively, P < 0.01) and ion-exchange fast protein liquid chromatography. Mass spectrometry confirmed LKB1 protein detection in the 60-kDa protein band, while none was detected in the 50-kDa band. Coimmunoprecipitation assays demonstrated LKB1-MO25-STRAD complex formation. Quantitative PCR revealed significantly reduced LKB1, MO25α, and STRADβ mRNA in LKB1−/− muscle. These findings demonstrate that the LKB1-MO25-STRAD complex is the principal AMPKK in skeletal muscle.
Cardiac and vascular responses to thigh cuffs and respiratory maneuvers on crewmembers of the International Space Station
Authors: Hamilton Douglas R. , Sargsyan Ashot E. , Garcia Kathleen , Ebert Douglas J. , Whitson Peggy A. , Feiveson Alan H. , Alferova Irina V. , Dulchavsky Scott A. , Matveev Vladimir P. , Bogomolov Valery V. , Duncan J. Michael
Published: September 2011

Background: the transition to microgravity eliminates the hydrostatic gradients in the vascular system. The resulting fluid redistribution commonly manifests as facial edema, engorgement of the external neck veins, nasal congestion, and headache. This experiment examined the responses to modified Valsalva and Mueller maneuvers measured by cardiac and vascular ultrasound (ECHO) in a baseline steady state and under the influence of thigh occlusion cuffs available as a countermeasure device (Braslet cuffs). Methods: nine International Space Station crewmember subjects (expeditions 16–20) were examined in 15 experiment sessions 101 ± 46 days after launch (mean ± SD; 33–185). Twenty-seven cardiac and vascular parameters were obtained with/without respiratory maneuvers before and after tightening of the Braslet cuffs (162 parameter states/session). Quality of cardiac and vascular ultrasound examinations was assured through remote monitoring and guidance by investigators from the NASA Telescience Center in Houston, TX, and the Mission Control Center in Korolyov, Moscow region, Russia. Results: 14 of 81 conditions (27 parameters measured at baseline, Valsalva, and Mueller maneuver) were significantly different when the Braslet was applied. Seven of 27 parameters were found to respond differently to respiratory maneuvers depending on the presence or absence of thigh compression. Conclusions: acute application of Braslet occlusion cuffs causes lower extremity fluid sequestration and exerts commensurate measurable effects on cardiac performance in microgravity. Ultrasound techniques to measure the hemodynamic effects of thigh cuffs in combination with respiratory maneuvers may serve as an effective tool in determining the volume status of a cardiac or hemodynamically compromised patient at the “microgravity bedside.”
The role of sympathetic nervous system in the development of neurogenic pulmonary edema in spinal cord-injured rats
Authors: Šedý Jiří , Zicha Josef , Nedvídková Jara , Kuneš Jaroslav
Published: September 2011

The pronounced activation of sympathetic nervous system is a necessary prerequisite for the development of neurogenic pulmonary edema (NPE) in rats with balloon compression of spinal cord. In this study we examined whether this is a consequence of rapid activation of spinal pathways leading to sympathetic venoconstriction, blood pressure rise, and reflex bradycardia. We found that NPE development can be prevented by epidural upper thoracic anesthesia or by transection of the upper spinal cord. This indicates an important role of spinal pathways activation. NPE development can also be prevented by moderate blood loss, supporting the role of blood redistribution to pulmonary circulation. In rats developing NPE the catecholamine surge following spinal cord compression involved not only a dramatic increase of circulating norepinephrine but also of epinephrine levels. The pretreatment of rats with α-1 adrenoceptor blocker prazosin, α-2 adrenoceptor blocker yohimbine, or calcium channel blocker nifedipine prevented NPE development, whereas the effect of β-adrenoceptor blockade with propranolol was less convincing. In conclusion, considerable activation of thoracic spinal pathways, followed by marked catecholamine secretion, play a major role in the development of NPE in spinal cord-injured rats. Enhanced α-adrenergic nifedipine-sensitive vasoconstriction is responsible for observed blood pressure changes, subsequent baroreflex bradycardia, and blood volume redistribution, which represent major pathogenetic mechanisms of NPE development.
Rapamycin decreases airway remodeling and hyperreactivity in a transgenic model of noninflammatory lung disease
Authors: Kramer Elizabeth L. , Hardie William D. , Mushaben Elizabeth M. , Acciani Thomas H. , Pastura Patricia A. , Korfhagen Thomas R. , Hershey Gurjit Khurana , Whitsett Jeffrey A. , Le Cras Timothy D.
Published: September 2011

Airway hyperreactivity (AHR) and remodeling are cardinal features of asthma and chronic obstructive pulmonary disease. New therapeutic targets are needed as some patients are refractory to current therapies and develop progressive airway remodeling and worsening AHR. The mammalian target of rapamycin (mTOR) is a key regulator of cellular proliferation and survival. Treatment with the mTOR inhibitor rapamycin inhibits inflammation and AHR in allergic asthma models, but it is unclear if rapamycin can directly inhibit airway remodeling and AHR, or whether its therapeutic effects are entirely mediated through immunosuppression. To address this question, we utilized transforming growth factor-α (TGF-α) transgenic mice null for the transcription factor early growth response-1 (Egr-1) (TGF-α Tg/Egr-1ko/ko mice). These mice develop airway smooth muscle thickening and AHR in the absence of altered lung inflammation, as previously reported. In this study, TGF-α Tg/Egr-1ko/ko mice lost body weight and developed severe AHR after 3 wk of lung-specific TGF-α induction. Rapamycin treatment prevented body weight loss, airway wall thickening, abnormal lung mechanics, and increases in airway resistance to methacholine after 3 wk of TGF-α induction. Increases in tissue damping and airway elastance were also attenuated in transgenic mice treated with rapamycin. TGF-α/Egr-1ko/ko mice on doxycycline for 8 wk developed severe airway remodeling. Immunostaining for α-smooth muscle actin and morphometric analysis showed that rapamycin treatment prevented airway smooth muscle thickening around small airways. Pentachrome staining, assessments of lung collagen and fibronectin mRNA levels, indicated that rapamycin also attenuated fibrotic pathways induced by TGF-α expression for 8 wk. Thus rapamycin reduced airway remodeling and AHR, demonstrating an important role for mTOR signaling in TGF-α-induced/EGF receptor-mediated reactive airway disease.
Dose-dependent increases in flow-mediated dilation following acute cocoa ingestion in healthy older adults
Authors: Monahan Kevin D. , Feehan Robert P. , Kunselman Allen R. , Preston Amy G. , Miller Debra L. , Lott Mary E. J.
Published: September 2011

An inverse relation exists between intake of flavonoid-rich foods, such as cocoa, and cardiovascular-related mortality. Favorable effects of flavonoids on the endothelium may underlie these associations. We performed a randomized, double-blind, placebo-controlled study to test the hypothesis that acute cocoa ingestion dose dependently increases endothelium-dependent vasodilation, as measured by an increase in brachial artery flow-mediated dilation (FMD), in healthy older adults. Measurements were obtained before (preingestion) and after (1- and 2-h postingestion) ingestion of 0 (placebo), 2, 5, 13, and 26 g of cocoa in 23 adults (63 ± 2 yr old, mean ± SE). Changes in brachial artery FMD 1- and 2-h postingestion compared with preingestion were used to determine the effects of cocoa. FMD was unchanged 1 (Δ−0.3 ± 0.2%)- and 2-h (Δ0.1 ± 0.1%) after placebo (0 g cocoa). In contrast, FMD increased both 1-h postingestion (2 g cocoa Δ0.0 ± 0.2%, 5 g cocoa Δ0.8 ± 0.3%, 13 g cocoa Δ1.0 ± 0.3%, and 26 g cocoa Δ1.6 ± 0.3%: P < 0.05 compared with placebo for 5, 13, and 26 g cocoa) and 2-h postingestion (2 g cocoa Δ0.5 ± 0.3%, 5 g cocoa Δ1.0 ± 0.3%, 13 g cocoa Δ1.4 ± 0.2%, and 26 g cocoa Δ2.5 ± 0.4%: P < 0.05 compared with placebo for 5, 13, and 26 g cocoa) on the other study days. A serum marker of cocoa ingestion (total epicatechin) correlated with increased FMD 1- and 2-h postingestion ( r = 0.44–0.48; both P < 0.05). Collectively, these results indicate that acute cocoa ingestion dose dependently increases brachial artery FMD in healthy older humans. These responses may help to explain associations between flavonoid intake and cardiovascular-related mortality in humans.
Severe Neuropsychiatric Reaction in a Deployed Military Member after Prophylactic Mefloquine
Authors: Peterson Alan L. , Seegmiller Robert A. , Schindler Libby S.
Published: September 2011

Recent studies of military personnel who have deployed to Iraq and Afghanistan have reported a number of combat-related psychiatric disorders such as posttraumatic stress disorder, depression, and traumatic brain injury. This case report involves a 27-year-old male active-duty US military service member who developed severe depression, psychotic hallucinations, and neuropsychological sequelae following the prophylactic use of the antimalarial medication mefloquine hydrochloride. The patient had a recent history of depression and was taking antidepressant medications at the time of his deployment to the Middle East. Psychiatrists and other health care providers should be aware of the possible neuropsychiatric side effects of mefloquine in deployed military personnel and should consider the use of other medications for malaria prophylaxis in those individuals who may be at increased risk for side effects.
Retroperitoneal Leiomyosarcoma Presenting as Lower Gastrointestinal Bleeding: A Case Report and Review of the Literature
Authors: Ventura Dominic G. , Thakkar Shyam J. , Farah Katie
Published: September 2011

We report the first known case of a retroperitoneal leiomyosarcoma that presented with an endoscopically defined source of gastrointestinal bleeding in the colon. A 68-year-old male with a history of diverticulosis, hypertension, and hypercholesterolemia who complained of a 3-month history of abdominal pain, nausea, and intermittent hematochezia presented for evaluation of large volume hematochezia and lightheadedness. Colonoscopy revealed left-sided diverticulosis and rectal varices without stigmata of recent bleed. CT scan showed a 26 × 20 × 13 cm heterogeneous retroperitoneal mass and multiple hypodense hepatic lesions. Liver biopsy revealed leiomyosarcoma. In summary, although surgery is the mainstay of treatment, resectability has not improved significantly. Early recognition and aggressive surgery are keys to long-term survival.
Novel Sonic Hedgehog Mutation in a Couple with Variable Expression of Holoprosencephaly
Authors: Aguinaga M. , Llano I. , Zenteno J. C. , Kofman Alfaro S.
Published: September 2011

Holoprosencephaly (HPE) is the most common developmental defect of the forebrain and midface in humans. sporadic and inherited mutations in the human sonic hedgehog (SHH) gene cause 37% of familial HPE. A couple was referred to our unit with a family history of two spontaneous first trimester miscarriages and a daughter with HPE who presented early neonatal death. The father had a repaired median cleft lip, absence of central incisors, facial medial hypoplasia, and cleft palate. Intelligence and a brain CT scan were normal. Direct paternal sequencing analysis showed a novel nonsense mutation (W127X). Facial characteristics are considered as HPE microforms, and the pedigree suggested autosomal dominant inheritance with a variable expression of the phenotype. This study reinforces the importance of an exhaustive evaluation of couples with a history of miscarriages and neonatal deaths with structural defects.
Ten Years of Severe Vitreomacular Traction Syndrome without Functional Damage Demonstrated by Optical Coherence Tomography
Authors: Reibaldi Michele , Avitabile Teresio , Uva Maurizio Giacinto , Occhipinti Francesco , Toro Mario , Zagari Marco , Russo Andrea
Published: September 2011

Introduction.To describe anatomical and functional features in one patient with 10 years of severe vitreomacular traction syndrome (VTS) without functional damage demonstrated by optical coherence tomography (OCT).Patient and Methods.One patient with a history of 10 years VTS, with best-corrected visual acuity of 20/32, was followed up with OCT. Follow-up examinations, 3 months for the first year after diagnosis and every 6 months for the subsequent years, were performed.Results.Follow-up examinations showed no change anatomically and functionally. Far and near visual acuity was unchanged. OCT by Heidelberg Spectralis did not evidence differences from Stratus OCT images.Conclusion.VTS can be stable anatomically and functionally for 10 years. OCT is a valuable diagnostic tool in understanding the configuration of vitreomacular adhesion, followup, and eventually planning the surgical approach for operating on VTS.
A Phase 2 Trial of Dasatinib in Patients with Advanced HER2-Positive and/or Hormone Receptor–Positive Breast Cancer
Authors: Mayer Erica L. , Baurain Jean-Francois , Sparano Joseph , Strauss Lewis , Campone Mario , Fumoleau Pierre , Rugo Hope , Awada Ahmad , Sy Oumar , Llombart-Cussac Antonio
Published: September 2011

Purpose: SRC-family kinases (SFK) are involved in numerous oncogenic signaling pathways. A phase 2 trial of dasatinib, a potent oral tyrosine kinase inhibitor of SFKs, was carried out in patients with human epidermal growth factor receptor 2–positive (HER2+) and/or hormone receptor–positive (HR+) advanced breast cancer.

Experimental Design: Patients with measurable tumors and progression after chemotherapy and HER2 and/or HR-targeted agents in adjuvant or metastatic settings (maximum of two prior metastatic setting regimens) received twice daily dasatinib. Primary endpoint was Response Evaluation Criteria in Solid Tumors–defined response rate. Secondary endpoints included toxicity and limited pharmacokinetics.

Results: Seventy patients (55 years median age) were treated, 83% of HER2+ patients had received prior HER2-directed therapy, and 61% of HR+ patients had received prior endocrine therapy in the advanced setting. Dasatinib starting dose was reduced from 100 to 70 mg twice daily to limit toxicity. Median therapy duration was 1.8 months in both dose groups and most discontinuations were due to progression. Of 69 evaluable patients, three had confirmed partial responses and six had stable disease for 16 weeks or more (disease control rate = 13.0%); all nine of these tumors were HR+ (two were also HER2+). The most common drug-related toxicities were gastrointestinal complaints, headache, asthenia, and pleural effusion. Grade 3–4 toxicity occurred in 37% of patients and was comparable between doses; drug-related serious adverse events were less frequent with 70 mg twice daily than 100 mg twice daily.

Conclusion: Limited single-agent activity was observed with dasatinib in patients with advanced HR+ breast cancer. Clin Cancer Res; 17(21); 6897–904. ©2011 AACR.
BCR–ABL Transcript Dynamics Support the Hypothesis That Leukemic Stem Cells Are Reduced during Imatinib Treatment
Authors: Stein Andrew M. , Bottino Dean , Modur Vijay , Branford Susan , Kaeda Jaspal , Goldman John M. , Hughes Timothy P. , Radich Jerald P. , Hochhaus Andreas
Published: September 2011

Purpose: Imatinib induces a durable response in most patients with Philadelphia chromosome–positive chronic myeloid leukemia, but it is currently unclear whether imatinib reduces the leukemic stem cell (LSC) burden, which may be an important step toward enabling safe discontinuation of therapy. In this article, we use mathematical models of BCR–ABL levels to make inferences on the dynamics of LSCs.

Experimental Design: Patients with at least 1 BCR–ABL transcript measurement on imatinib were included (N = 477). Maximum likelihood methods were used to test 3 potential hypotheses of the dynamics of BCR–ABL transcripts on imatinib therapy: (i) monoexponential, in which there is little, if any, decline in BCR–ABL transcripts; (ii) biexponential, in which patients have a rapid initial decrease in BCR–ABL transcripts followed by a more gradual response; and (iii) triexponential, in which patients first exhibit a biphasic decline but then have a third phase when BCR–ABL transcripts increase rapidly.

Results: We found that most patients treated with imatinib exhibit a biphasic decrease in BCR–ABL transcript levels, with a rapid decrease during the first few months of treatment, followed by a more gradual decrease that often continues over many years.

Conclusions: We show that the only hypothesis consistent with current data on progenitor cell turnover and with the long-term, gradual decrease in the BCR–ABL levels seen in most patients is that these patients exhibit a continual, gradual reduction of the LSCs. This observation may explain the ability to discontinue imatinib therapy without relapse in some cases. Clin Cancer Res; 17(21); 6812–21. ©2011 AACR.
Comparative Temporospatial Expression Profiling of Murine Amelotin Protein during Amelogenesis
Authors: Somogyi-Ganss Eszter , Nakayama Yohei , Iwasaki Kengo , Nakano Yukiko , Stolf Daiana , McKee Marc D. , Ganss Bernhard
Published: September 2011

Tooth enamel is formed in a typical biomineralization process under the guidance of specific organic components. Amelotin (AMTN) is a recently identified, secreted protein that is transcribed predominantly during the maturation stage of enamel formation, but its protein expression profile throughout amelogenesis has not been described in detail. The main objective of this study was to define the spatiotemporal expression profile of AMTN during tooth development in comparison with other known enamel proteins. A peptide antibody against AMTN was raised in rabbits, affinity purified and used for immunohistochemical analyses on sagittal and transverse paraffin sections of decalcified mouse hemimandibles. The localization of AMTN was compared to that of known enamel proteins amelogenin, ameloblastin, enamelin, odontogenic ameloblast-associated/amyloid in Pindborg tumors and kallikrein 4. Three-dimensional images of AMTN localization in molars at selected ages were reconstructed from serial stained sections, and transmission electron microscopy was used for ultrastructural localization of AMTN. AMTN was detected in ameloblasts of molars in a transient fashion, declining at the time of tooth eruption. Prominent expression in maturation stage ameloblasts of the continuously erupting incisor persisted into adulthood. In contrast, amelogenin, ameloblastin and enamelin were predominantly found during the early secretory stage, while odontogenic ameloblast-associated/amyloid in Pindborg tumors and kallikrein 4 expression in maturation stage ameloblasts paralleled that of AMTN. Secreted AMTN was detected at the interface between ameloblasts and the mineralized enamel. Recombinant AMTN protein did not mediate cell attachment in vitro. These results suggest a primary role for AMTN in the late stages of enamel mineralization.
Contextual Determination of Human Thinking: About Some Conceptual and Methodological Obstacles in Psychology Studies
Authors: Sorsana Christine , Trognon Alain
Published: September 2011

This theoretical paper discusses some conceptual and methodological obstacles that one encounters when analyzing the contextual determination of thinking in psychology. First, we comment upon the various representations of the ‘cognitive’ individual that have been formed over the years – from the epistemic subject to the psychological subject, and finally, to the psychosocial actor. Second, we recall the main criticisms of ‘methodological solipsism’ found in cognitive psychology research, and we discuss heuristic methods for analyzing the contextual determination of thinking in psychological studies. Finally, we propose an analysis of some data using the approach based on interlocutory logic as a way to formalize reasoning moves and their transformations in the unfolding interaction.
Reliable and Valid Assessment of Clinical Bronchoscopy Performance
Authors: Konge Lars , Larsen Klaus Richter , Clementsen Paul , Arendrup Henrik , von Buchwald Christian , Ringsted Charlotte
Published: September 2011

Background: There have been several attempts to systematically assess performance in bronchoscopy. Earlier validation studies have used bronchoscopy simulators, not real-life performance in patients. Objectives: The aim of this study was to explore the reliability and validity of an assessment tool aimed for the use in a clinical setting. Methods: Five junior residents, 5 senior residents and 9 consultants performed 3 bronchoscopies each. All 57 bronchoscopies were video-recorded and assessed blindly and independently by two bronchoscopy experts using the new assessment tool. Results: The interrater reliability was high, with Cronbach’s α = 0.86. Assessment of 3 bronchoscopies by a single rater had a generalizability coefficient of 0.84. The correlation between experience and performance was good (Pearson correlation = 0.76). There were significant differences between the groups for all aspects of the assessment, but post hoc tests showed different discriminative abilities. Conclusions: This new tool for assessing clinical bronchoscopy performance has a high interrater reliability. One rater assessing performance of 3 bronchoscopies ensures sufficient reliability. The assessment tool demonstrated sufficient construct validity.
Does Patient Gender Affect Outcomes after Concomitant Coronary Artery Bypass Graft and Aortic Valve Replacement? An Australian Society of Cardiac and Thoracic Surgeons Database Study
Authors: Saxena Akshat , Poh Chin-Leng , Dinh Diem T. , Reid Christopher M. , Smith Julian A. , Shardey Gilbert C. , Newcomb Andrew E.
Published: September 2011

Objectives: Women undergoing isolated coronary artery bypass graft (CABG) surgery have been previously shown to be at an independently increased risk for post-operative morbidity and mortality. However, there are considerably less data on whether this trend remains true in patients undergoing concomitant aortic valve replacement (AVR) and CABG surgery. The aim of our study was to investigate this pertinent issue. Methods: Data obtained between June 2001 and December 2009 by the Australasian Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database Program were retrospectively analysed. Demographic, operative data and post-operative complications were compared between male and female patients using χ2 and t tests. Long-term survival analysis was performed using Kaplan-Meier survival curves and the log-rank test. Independent risk factors for short- and long-term mortality were identified using binary logistic and Cox regression, respectively. Results: Concomitant AVR and CABG surgery was undertaken in 2,563 patients; 31.8% were female. Female patients were older (mean age 76 vs. 73 years; p < 0.001) and presented more often with hypertension (p < 0.001) but less often with severely impaired ejection fraction (p < 0.001), peripheral vascular disease (p < 0.001) and triple vessel disease (p < 0.001). Women did not demonstrate an increased risk of 30-day mortality (4.8 vs. 3.3%) on univariate (p = 0.069) or multivariate (p = 0.236) analysis. Female gender was independently associated with post-operative myocardial infarction (p = 0.022) and red blood cell transfusion (p < 0.001). There was no difference in long-term survival between men and women on multivariate analysis (p = 0.413). Conclusion: Female gender is not associated with poorer short- or long-term outcomes after concomitant CABG and AVR surgery.
Developmental Context(s): Mediating Learning through Language Ideologies
Authors: Razfar Aria , Rumenapp Joseph C.
Published: September 2011

This paper argues for an expanded notion of context and the mediational tools that frame language learning. More specifically, we argue for a more explicit understanding of language ideologies as a key mediating tool and object in learning and development. Language ideologies bring coherence to the interaction of macro-historical processes, micro-discursive practices, and the emerging context(s) of development. The article begins with a framing of the argument within the historical genesis of ‘context’ in sociocultural research. We argue for a cohesive model of language ideologies, activity, and the social organization of learning. Then we proceed to illustrate the multiplicity of mediational artifacts that can be analyzed using a language ideologies perspective. We illustrate our case by drawing on multiple sources of evidence collected in the course of an ethnographic case study of three English learner classrooms. Finally we discuss the implications in light of restrictive language policies and learning outcomes for English learners and other speakers of ‘nonstandard’ varieties.