bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of barriers for physical activity in Portuguese adolescents
Authors: Gomes Hilário , Pinto Diogo , Sequeira Sebastião , Santos Luís , Marques Adilson , Carreiro da Costa Francisco
Published: November 2011

The aim of this study was to analyse the prevalence of barriers to physical activity (PA) among adolescents according to gender and practice of PA. A total of 2580 adolescents (1310 boys, 1270 girls) aged ranged between 10 and 18 years old (mean 13±2 y) participated in this study. The data was collected through a questionnaire on PA's participation and barriers to PA. Qui-square tests were performed to analyse the differences between the gender and the practice of PA on perceived barriers. Only 29% of boys and 12% of girls were considered active. The most common barriers to the engagement in PA were the same for boys and girls. Nevertheless there were significant differences between the two genders. The number one barrier was – lack of time (boys 16%, girls 26%,p<0.001), the second was interest in doing another thing (boys 9%, girls 13%,p=0.003), and the third was the perception of not having enough skills (boys 5%, girls 10%,p<0.001). Girls reported higher importance to shame (p=0.004) and to the costs (p=0.001) associated with PA. For the group of active students the main barrier was lack of time (9%) while the less active students cited more often the interest of doing something else (12%) and not having enough skills (9%). Additional relevant differences were observed between active and inactive students on the importance of the barrier, lack of time (p<0.001), not being in shape (p=0.001), the perception of not having enough skills (p<0.001), costs (p=0.002) and interest in doing another thing (p<0.001). All of these reasons were more prevalent for inactive students except physically active students cited more often the lack of time (89% vs 3%,p<0.001). Lack of time is the most cited barrier for boys and girls. In general, perceived barriers for the practice of PA were more prevalent for girls than for boys. The inactive students reported more motives than the active ones.
The physiological effect of 800 mcg and 1600 mcg inhaled salbutamol during a football specific treadmill run at high ambient temperatures
Authors: Dickinson J , Hu J , Chester N , Drust B , Whyte G , Loosemore M
Published: November 2011

The World Anti-doping Agency stipulates that athletes who declare salbutamol use should not exceed 1600 μg over a 24 h period. No studies have investigated the physiological effect of 1600 μg of inhaled salbutamol on intermittent sports. This study investigated the physiological effect of inhaling 800 μg and 1600 μg of salbutamol prior to a football specific run at high ambient temperatures. Five male non-asthmatic football players (mean+SD; age 24+4 y; weight 71+4 kg; height 175+5 cm) volunteered. Participants attended the lab on three occasions to inhale either a placebo (PLA), 800 μg of salbutamol (800SAL) or 1600 μg of salbutamol (1600SAL) 15 min prior to performing a football-specific run for 45 min at 30°C. The football specific run consisted of seven stages which included two high intensity stages and five low intensity stages. During each stage VO2, RER, HR and blood lactate was measured. Repeated measures ANOVA were performed to investigate the changes in VO2, RER, HR and blood lactate during each stage. Significance was assumed if p<0.05. During stage one and two HR was higher (p=0.010; p=0.013) in 800SAL (143.3+10.3 b.min-1; 148.0+12.2 b.min-1) and 1600SAL (141.6+2.5 b.min-1; 147.0+4.0 b.min-1) when compared to PLA (119.3+11.9 b.min-1; 129.3+9.6 b.min-1). Following stage two blood lactate was higher (p=0.020) in 800SAL (4.2+1.8 mmol.l-1) and 1600SAL (4.5+1.6 mmol.l-1) when compared with PLA (2.4+1.2 mmol.l-1). Following stage five blood lactate was higher (p=0.014) in 800SAL (4.2+1.6 mmol.l-1) and 1600SAL (5.0+1.4 mmol.l-1) when compared with PLA (2.8+1.0 mmol.l-1). The increased HR (stages one and two) and increased blood lactate concentration (stages two and five) observed following salbutamol inhalation, suggestssupratherapeuticdoses of salbutamol may increase the physiological cost during a football match.
The epidemiology of cross country skiing injuries
Authors: Howes J , Droog S J , Evans J , Wood I M , Wood A M
Published: November 2011

There is little literature about the epidemiology of injuries sustained while conducting cross country skiing due to the disparate nature of these athletes. The Royal Marines regularly deploys to Norway to conduct cross country ski-training and cold weather warfare training which presents a unique opportunity to analyse injuries sustained while conducting this sport. A total of 1200 personnel deployed to Norway in 2010 over a 14 week period. Patients who sustained injuries who were unable to continue training were returned to the UK. All data on personnel returned to the UK due to injury or illness was prospectively collected and basic epidemiology recorded. 53 patients (incidence 44/1000 personnel) were returned to the UK 20/53 (38%) of all cases were musculoskeletal injuries (incidence 17/1000 personnel). 15/20 musculoskeletal injuries were sustained while conducting cross country ski training (incidence 13/1000). Injuries sustained while skiing: 5/15 sustained anterior shoulders dislocation, 5/15 Grade 1–3 MCL/LCL tears, 2/15 sustained ACJ injuries, 1/15 crush fracture T11/T12, 1/15 tibial plateau fracture and 1/15 significant ankle sprain. The most common injury regardless of cause was anterior shoulder dislocation 6/20 (incidence 5/1000). Our results suggest that cross country ski training has a high injury rate requiring evacuation back to the UK. In our study group the high injury rate is possibly due to the rapid transition from non-skier to skiing with a bergen and weapon. Doctors covering Royal Marine training should have appropriate sports and exercise medical training, and rehabilitation units supporting the Royal Marines should expect sudden increases in referrals when large-scale cross country ski training is being conducted.
Photoperiod has a stronger impact than irradiance on the source–sink relationships in the sink-limited species Erythronium americanum
Authors: Gandin Anthony , Dizengremel Pierre , Lapointe Line
Published: November 2011

Under sink-limited conditions, source activity is modulated to remain in balance with the use of carbohydrates by the sink, but this feedback control has been studied in only a few systems so far. Sink and source activities were investigated throughout the season. Plants were subjected to two photoperiod regimes combined with two irradiance levels to produce three different daily amounts of photons. Net photosynthetic rate and the photochemical efficiency of photosynthesis were initially higher under a long photoperiod, but decreased early in the growth season, whereas they remained fairly constant until a few days before leaf senescence under a short photoperiod. The rates of starch and biomass accumulation in the bulb were also faster under a long photoperiod at the beginning of the season but reached similar levels under both short and long photoperiods later on. Response to photoperiod cannot be explained by changes in daily amounts of photons, as none of the variables reported were affected by instantaneous or daily irradiance. It appears that the total amount of carbohydrate synthesized under a long photoperiod was in excess compared to the ability of the sink to store or use them, inducing a feedback inhibition of net photosynthetic rate to restore the source–sink balance.
The infection process of Puccinia xanthii f. sp. ambrosiae-trifidae on Ambrosia trifida
Authors: Zhang Ping , Lu Guo-zhong , Sun Xiao-dong , Zhang Wei , Qu Bo , Tian Xiu-ling
Published: November 2011

Puccinia xanthii Schwein. f. sp. ambrosiae-trifidae S.W.T. Batra is an obligate parasitic rust fungus of Ambrosia trifida Linn. Field investigations in Liaoning Province, China, showed that it is an effective biocontrol agent of this alien invasive weed. Its infection of the plant was observed by light microscopy combined with Coomassie Brilliant Blue R-250 staining. We report the infection process, including teliospore germination and basidiospore formation on the host leaf surface, penetration of host tissue, and development of fungal hyphae within the host tissue. Fresh teliospores began to germinate from the germ pore within 1 h under suitable conditions and soon produced basidiospores or secondary basidiospores. Basidiospores falling on host leaves germinated from the end of the basidiospore opposite to the apiculus. Appressoria of germ tubes tended to orient along leaf epidermis cell ridges or at junctions near stomata rather than fixing randomly on the leaf surface. These germ tubes grew for short or longer distances before forming appressoria. The rust fungus directly penetrated the host epidermis by infectious pegs rather than through stomata. Within host tissues, the rust fungus formed intraepidermal vesicles, primary hyphae, intracellular hyphae, and M-haustoria. The intricate infectious structures formed by P. xanthii f. sp. ambrosiae-trifidae on or in host tissues suggest that the rust fungus is a suitable organism for researching the interaction between the pathogen and host plant.
Photodynamically active phthalocyanine building blocks for click chemistry
Authors: Novakova Veronika , Kopecky Kamil , Miletin Miroslav , Ivincova Jana , Zimcik Petr
Published: November 2011

Synthesis of symmetrical and unsymmetrical zinc phthalocyanines from two different precursors 4,5-bis(tert-butylsulfanyl)phthalonitrile (A) and N-(3-azidopropyl)-2,3-dicyanoquinoxaline-6-carboxamide (B) is described. Congeners of AAAA, AAAB, ABAB and AABB type were isolated by a chromatographic technique, however, the congener of BBBB type had to be prepared in a separate reaction. The adjacent and opposite isomers were also separated and fully characterized. Isolated phthalocyanines contained different number of azide groups, a substrate for highly efficient Cu(I) -catalyzed azide-alkyne 1,3-dipolar cycloaddition ("click chemistry"). All phthalocyanines absorbed strongly (ε over 150 000 M-1.cm-1) over 700 nm. Their singlet oxygen quantum yields were determined in DMF and ranged from 0.63 to 0.79, fluorescence quantum yields in DMF were considerably lower in the range 0.03–0.06. All these properties make them suitable building blocks for a simple modification and a synthesis of phthalocyanines with better tuned properties for photodynamic therapy.
VACUUM POLARIZATION IN A COSMIC STRING SPACETIME INDUCED BY FLAT BOUNDARY
Authors: BEZERRA DE MELLO EUGÊNIO R. , SAHARIAN ARAM A.
Published: November 2011

In this paper we analyze the vacuum expectation values of the field squared and the energy-momentum tensor associated to a massive scalar field in a higher dimensional cosmic string spacetime, obeying Dirichlet or Neumann boundary conditions on the surface orthogonal to the string.
GRAVITATIONAL WAVES FROM EJECTION OF JET SUPERLUMINAL COMPONENTS AND PRECESSION OF ACCRETION DISKS DYNAMICALLY DRIVEN BY BARDEEN-PETTERSON EFFECT
Authors: MOSQUERA CUESTA HERMAN J. , SÁNCHEZ LUIS A. , PARDO DANIEL ALFONSO , CAPRONI ANDERSON , ABRAHAM ZULEMA , NUÑEZ LUIS HENRY QUIROGA
Published: November 2011

Jet superluminal components are recurrently ejected from active galactic nuclei, micro-quasars, T-Tauri star, and several other astrophysical systems, including gamma-ray burst sources. The mechanism driving this powerful phenomenon is not properly settled down yet. In this article we suggest that ejection of ultrarelativistic components may be associated to the superposition of two actions: precession of the accretion disk induced by the Kerr black hole (KBH) spin, and fragmentation of the tilted disk; this last being an astrophysical phenomenon driven by the general relativistic Bardeen-Petterson (B-P) effect. As fragmentation of the accretion disk takes place at the B-P transition radius, the incoming material that get trapped in this sort of Lagrange internal point will forcibly precess becoming a source of continuous, frequency-modulated gravitational waves. At resonance blobs can be expelled at ultrarelativistic velocities from the B-P radius. The launching of superluminal components of jets should produce powerful gravitational wave (GW) bursts during its early acceleration phase, which can be catched on the fly by current GW observatories. Here we compute the characteristic amplitude and frequency of such signals and show that they are potentially detectable by the GW observatory LISA.
CAPACITANCE MEASUREMENTS AND ELECTROSTATIC CALIBRATIONS IN EXPERIMENTS MEASURING THE CASIMIR FORCE
Authors: DECCA R. S. , FISCHBACH E. , KLIMCHITSKAYA G. L. , KRAUSE D. E. , LÓPEZ D. , MOHIDEEN U. , MOSTEPANENKO V. M.
Published: November 2011

We discuss the possibility of determining the properties and quality of spherical surfaces used in precise experiments with the help of capacitance measurements. The results of this kind measurements for the lens-plane and sphere-plane, Au coated surfaces are compared with theoretical predictions from various models of perfect and broken sphericity. It is shown that capacitance measurements are incapable of discriminating between models of perfect and modified centimeter-size spherical surfaces in an experiment demonstrating the anomalous scaling law for the electric force. Claims to the contrary in the recent literature are explained by the use of improper comparison. The data from capacitance measurements in an experiment measuring the Casimir force by means of a micromechanical torsional oscillator employing micrometer-size spheres are shown to be in excellent agreement with theoretical predictions using the model of a perfect spherical surface.
GENERAL RELATIVITY AND WEYL FRAMES
Authors: ROMERO C. , FONSECA-NETO J. B. , PUCHEU M. L.
Published: November 2011

We present the general theory of relativity in the language of a non-Riemannian geometry, namely, Weyl geometry. We show that the new mathematical formalism may lead to different pictures of the same gravitational phenomena, by making use of the concept of Weyl frames. We show that, in this formalism, it is possible to construct a scalar-tensor gravitational theory that is invariant with respect to the so-called Weyl tranformations and reduces to general relativity in a particular frame, the Riemann frame. In this approach the Weyl geometry plays a fundamental role since it appears as the natural geometrical setting of the theory when viewed in an arbitrary frame. Our starting point is to build an action that is manifestly invariant with respect to Weyl transformations. When this action is expressed in more familiar terms of Riemannian geometry we find that the theory has some similarities with Brans-Dicke theory of gravity. We illustrate this point with an example in which a known Brans-Dicke vacuum solution may appear when reinterpreted in a particular Weyl frame.
SOME REMARKS ON f(R) THEORIES OF GRAVITY
Authors: JORÁS SERGIO E.
Published: November 2011

In this paper, I make a brief review of f(R) theories and their shortcomings — with some emphasis on the latter. I constrain myself to f(R) theories, the current acceleration of the (homegeneous) universe and the metric formalism (except at the very end).
TOPOLOGICAL PROPERTIES FROM EINSTEIN'S EQUATIONS
Authors: MONTE EDMUNDO M.
Published: November 2011

In this work we propose a new procedure on how to extract global information of a space-time. We consider a space-time immersed in a higher dimensional space and formulate the equations of Einstein through the Frobenius conditions of immersion. Through an algorithm and implementation into algebraic computing system we calculate normal vectors from the immersion to find the second fundamental form. We make an application for a static space-time with spherical symmetry. We solve Einstein's equations in the vacuum and obtain space-times with different topologies.
NON-COMMUTATIVE EINSTEIN EQUATIONS AND SEIBERG–WITTEN MAP
Authors: ASCHIERI PAOLO , DI GREZIA ELISABETTA , ESPOSITO GIAMPIERO
Published: November 2011

The Seiberg–Witten map is a powerful tool in non-commutative field theory, and it has been recently obtained in the literature for gravity itself, to first order in non-commutativity. This paper, relying upon the pure-gravity form of the action functional considered in Ref. 2, studies the expansion to first order of the non-commutative Einstein equations, and whether the Seiberg–Witten map can lead to a solution of such equations when the underlying classical geometry is Schwarzschild. We find that, if one first obtains the non-commutative field equations by varying the action of Ref. 2 with respect to all non-commutative fields, and then tries to solve these equations by expressing the non-commutative fields in terms of the commutative ones via Seiberg–Witten map, no solution of these equations can be obtained when the commutative background is Schwarzschild.
TIME EVOLUTION OF SCALAR-TENSOR COSMOLOGIES IN THE GENERAL RELATIVITY LIMIT
Authors: SAAL MARGUS , JÄRV LAUR , KUUSK PIRET
Published: November 2011

We consider Friedmann-Lemaître-Robertson-Walker flat cosmological models in the framework of general Jordan frame scalar-tensor theories of gravity in two different cases: in the dust matter dominated era and in the potential dominated era. Motivated by the local weak field constraints and by cosmological observations, we develop and use an approximation scheme for the regime close to the so-called limit of general relativity. The ensuing nonlinear approximate equations for the scalar field can be solved analytically in cosmological time in both cases. We find criteria for the functions ω and V characterizing a scalar-tensor theory, to determine whether the theory does or does not possess solutions converging to general relativity asymptotically in time. The converging solutions can be subsumed under two principal classes: exponentional or polynomial convergence, and damped oscillations around general relativity. The classes of scalar-tensor theories of gravity which contain these types of solutions and satisfy observational constraints, are candidates to explain possible deviations from the standard ΛCDM model. Finally, the effective equation of state parameter w eff is used to illustrate possible asymptotic cosmological dynamics.
SEARCHING COSMOLOGICAL MODELS FROM THE PHENOMENOLOGY OF LARGE ACCELERATORS
Authors: KLIPPERT RENATO , DE LORENCI VITORIO A. , LI SHI-YUAN
Published: November 2011

The matter state appearing just after the inelastic hadronic collisions, presently called 'glasma', is here taken as the dominant matter-energy content of the early universe. As a result, an anisotropic cosmological toy-model is obtained in the limit of early times. This is a simple example of a collider physics motivated cosmology, the relevance of which relying in the occurrence of a true cosmic singularity (as usual big-bang models) despite the fact that the resulting metric tensor is regular everywhere.
BLACK HOLE AS A SUPERCOLLIDER
Authors: ZASLAVSKII O. B.
Published: November 2011

Recently, it was found that in the vicinity of the black hole horizon of a rotating black hole two particles can collide in such a way that the energy in their centre of mass frame becomes infinite (so-called BSW effect). I give a brief review of basic features of this effect and show that this is a generic property of rotating black holes. In addition, there exists its counterpart for radial motion of charged particles in the charged black hole background. Simple kinematic explanation is suggested that is based on observation that all massive particles fall in two classes. In the first case (by definition, "usual particles"), the velocity approaches that of light on the horizon in the locally-nonrotating frame due to special relationship between the energy and the angular momentum. In the second case, it tends to some value less than speed of light. As a result, the relative velocity also tends to the speed of light with infinitely growing Lorentz factor.
VACUUM ENERGY INDUCED BY AN IMPENETRABLE FLUX TUBE OF FINITE RADIUS
Authors: GORKAVENKO V. M. , SITENKO YU. A. , STEPANOV O. B.
Published: November 2011

We consider the effect of the magnetic field background in the form of a tube of the finite transverse size on the vacuum of the quantized charged massive scalar field which is subject to the Dirichlet boundary condition at the edge of the tube. The vacuum energy is induced, being periodic in the value of the magnetic flux enclosed in the tube. The dependence of the vacuum energy density on the distance from the tube and on the coupling to the space-time curvature scalar is comprehensively analyzed.
Glutamate transporter dysfunction associated with nerve injury-induced pain in mice
Authors: Napier Ian A. , Mohammadi Sarasa A. , Christie MacDonald J.
Published: November 2011

Dysfunction at glutamatergic synapses has been proposed as a mechanism in the development of neuropathic pain. Here we sought to determine whether peripheral nerve injury-induced neuropathic pain results in functional changes to primary afferent synapses. Signs of neuropathic pain as well as an induction of glial fibrillary acidic protein in immunostained spinal cord sections 4 days after partial ligation of the sciatic nerve indicated the induction of neuropathic pain. We found that following nerve injury, no discernable change to kinetics of dl-α-amino-3-hydroxy-5-methylisoxazole-propionic acid (AMPA) or N-methyl-d-aspartate receptor (NMDAR)-mediated evoked excitatory postsynaptic currents (eEPSCs) could be observed in dorsal horn (lamina I/II) neurons compared with those of naïve mice. However, we did find that nerve injury was accompanied by slowed decay of the early phase of eEPSCs in the presence of glutamate transporter inhibition by the competitive nontransportable inhibitor dl-threo-β-benzyloxyaspartic acid (TBOA). Concomitantly, expression patterns for the two major glutamate transporters in the spinal cord, excitatory amino acid transporters (EAAT) 1 and EAAT2, were found to be reduced at this time (4 days postinjury). We then sought to directly determine whether nerve injury results in glutamate spillover to NMDARs at dorsal horn synapses. By employing the use-dependent NMDAR blocker (±)MK-801 to block subsynaptic receptors, we found that although TBOA-induced spillover to extrasynaptic receptors trended to increased activation of these receptors after nerve injury, this was not significant compared with naïve mice. Together, these results suggest the development of neuropathic pain involves subtle changes to glutamate transporter expression and function that could contribute to neuropathic pain during excessive synaptic activity.
Molecular Diagnostics, Targeted Therapy, and the Indication for Allogeneic Stem Cell Transplantation in Acute Lymphoblastic Leukemia
Authors: Oyekunle Anthony , Haferlach Torsten , Kröger Nicolaus , Klyuchnikov Evgeny , Zander Axel Rolf , Schnittger Susanne , Bacher Ulrike
Published: November 2011

In recent years, the panel of known molecular mutations in acute lymphoblastic leukemia (ALL) has been continuously increased. In Philadelphia-positive ALL, deletions of theIKZF1gene were identified as prognostically adverse factors. These improved insights in the molecular background and the clinical heterogeneity of distinct cytogenetic subgroups may allow most differentiated therapeutic decisions, for example, with respect to the indication to allogeneic HSCT within genetically defined ALL subtypes. Quantitative real-time PCR allows highly sensitive monitoring of the minimal residual disease (MRD) load, either based on reciprocal gene fusions or immune gene rearrangements. Molecular diagnostics provided the basis for targeted therapy concepts, for example, combining the tyrosine kinase inhibitor imatinib with chemotherapy in patients with Philadelphia-positive ALL. Screening forBCR-ABL1mutations in Philadelphia-positive ALL allows to identify patients who may benefit from second-generation tyrosine kinase inhibitors or from novel compounds targeting the T315I mutation. Considering the central role of the molecular techniques for the management of patients with ALL, efforts should be made to facilitate and harmonize immunophenotyping, cytogenetics, and molecular mutation screening. Furthermore, the potential of high-throughput sequencing should be evaluated for diagnosis and follow-up of patients with B-lineage ALL.
Improvement of Physicochemical Characteristics of Monoepoxide Linoleic Acid Ring Opening for Biolubricant Base Oil
Authors: Salimon Jumat , Salih Nadia , Abdullah Bashar Mudhaffar
Published: November 2011

For environmental reasons, a new class of environmentally acceptable and renewable biolubricant based on vegetable oils is available. In this study, oxirane ring opening reaction of monoepoxide linoleic acid (MEOA) was done by nucleophilic addition of oleic acid (OA) with using p‐toluene sulfonic acid (PTSA) as a catalyst for synthesis of 9(12)‐hydroxy‐10(13)‐oleoxy‐12(9)‐octadecanoic acid (HYOOA) and the physicochemical properties of the resulted HYOOA are reported to be used as biolubricant base oils. Optimum conditions of the experiment using D‐optimal design to obtain high yield% of HYOOA and lowest OOC% were predicted at OA/MEOA ratio of 0.30 : 1 (w/w), PTSA/MEOA ratio of 0.50 : 1 (w/w), reaction temperature at 110 ∘C, and reaction time at 4.5 h. The results showed that an increase in the chain length of the midchain ester resulted in the decrease of pour point (PP) −51∘C, increase of viscosity index (VI) up to 153, and improvement in oxidative stability (OT) to 180.94 ∘C.
A Comparison of Imaging Techniques to Monitor Tumor Growth and Cancer Progression in Living Animals
Authors: Puaux Anne-Laure , Ong Lai Chun , Jin Yi , Teh Irvin , Hong Michelle , Chow Pierce K. H. , Golay Xavier , Abastado Jean-Pierre
Published: November 2011

Introduction and Purpose. Monitoring solid tumor growth and metastasis in small animals is important for cancer research. Noninvasive techniques make longitudinal studies possible, require fewer animals, and have greater statistical power. Such techniques include FDG positron emission tomography (FDG-PET), magnetic resonance imaging (MRI), and optical imaging, comprising bioluminescence imaging (BLI) and fluorescence imaging (FLI). This study compared the performance and usability of these methods in the context of mouse tumor studies. Methods. B16 tumor-bearing mice (n=4 for each study) were used to compare practicality, performance for small tumor detection and tumor burden measurement. Using RETAAD mice, which develop spontaneous melanomas, we examined the performance of MRI (n=6 mice) and FDG-PET (n=10 mice) for tumor identification. Results. Overall, BLI and FLI were the most practical techniques tested. Both BLI and FDG-PET identified small nonpalpable tumors, whereas MRI and FLI only detected macroscopic, clinically evident tumors. FDG-PET and MRI performed well in the identification of tumors in terms of specificity, sensitivity, and positive predictive value. Conclusion. Each of the four methods has different strengths that must be understood before selecting them for use.
Life-Threatening Hypocalcemia following Subtotal Parathyroidectomy in a Patient with Renal Failure and Previous Roux-en-Y Gastric Bypass Surgery
Authors: Palal Betsy , Sinsakul Marvin , Reutrakul Sirimon
Published: November 2011

Background.Roux-en-Y gastric bypass (RYGB) can result in calcium and vitamin D deficiency. Parathyroid surgery carries the risk of immediate and long-term hypocalcemia.Methods and Results.We describe a 54-year-old woman with history of end-stage renal disease and gastric bypass surgery who developed calciphylaxis requiring a 3.5-gland parathyroidectomy. Seven weeks later, she presented with weakness, perioral numbness, leg cramps, a positive Chvostek's sign, hypotension, prolonged QT-interval, and serum calcium of 5.4 mg/dL. Oral and intravenous calcium, calcitriol, and high calcium bath hemodialysis were given. She required 18 days of intravenous calcium and an outpatient maintenance regimen of calcitriol 6 mcg/day, calcium carbonate 8 grams/day, calcium citrate 1.2 grams/day, and ergocalciferol 50,000 IU/week.Conclusion.The patient's life-threatening prolonged hypocalcemia and large requirements of calcium and calcitriol were due to a combination of malabsorption, hypoparathyroidism, and renal failure. Special considerations should be given to bariatric surgery patients undergoing neck exploration.
Use of Cyclosporine in Uterine Transplantation
Authors: Saso Srdjan , Logan Karl , Abdallah Yazan , Louis Louay S. , Ghaem-Maghami Sadaf , Smith J. Richard , Del Priore Giuseppe
Published: November 2011

Uterine transplantation has been proposed as a possible solution to absolute uterine factor infertility untreatable by any other option. Since the first human attempt in 2000, various teams have tried to clarify which immunosuppressant would be most suitable for protecting the allogeneic uterine graft while posing a minimal risk to the fetus. Cyclosporine A (CsA) is an immunosuppressant widely used by transplant recipients. It is currently being tested as a potential immunosuppressant to be used during UTn. Its effect on the mother and fetus and its influence upon the graft during pregnancy have been of major concern. We review the role of CsA in UTn and its effect on pregnant transplant recipients and their offspring.
Reflux Revisited: Advancing the Role of Pepsin
Authors: Bardhan Karna Dev , Strugala Vicki , Dettmar Peter W.
Published: November 2011

Gastroesophageal reflux disease is mediated principally by acid. Today, we recognise reflux reaches beyond the esophagus, where pepsin, not acid, causes damage. Extraesophageal reflux occurs both as liquid and probably aerosol, the latter with a further reach. Pepsin is stable up to pH 7 and regains activity after reacidification. The enzyme adheres to laryngeal cells, depletes its defences, and causes further damage internally after its endocytosis. Extraesophageal reflux can today be detected by recognising pharyngeal acidification using a miniaturised pH probe and by the identification of pepsin in saliva and in exhaled breath condensate by a rapid, sensitive, and specific immunoassay. Proton pump inhibitors do not help the majority with extraesophageal reflux but specifically formulated alginates, which sieve pepsin, give benefit. These new insights may lead to the development of novel drugs that dramatically reduce pepsinogen secretion, block the effects of adherent pepsin, and give corresponding clinical benefit.
Unraveling the Relationship between Smoking and Weight: The Role of Sedentary Behavior
Authors: Kaufman Annette , Augustson Erik M. , Patrick Heather
Published: November 2011

Research has shown that current smokers have a lower mean body mass index (BMI) than never and former smokers, with former smokers having the highest mean BMI. A number of physiological mechanisms have been hypothesized to explain this pattern, but few studies have explored the possible role of behavioral factors. Using data from the cross-sectional National Health and Nutrition Examination Survey 1999–2006, this descriptive study explored the associations among smoking status, sedentary behavior, and two anthropometric measures (BMI and waist circumference (WC)). Sedentary behavior was significantly higher among current smokers compared to never and former smokers; former smokers had higher levels of sedentary behavior compared to never smokers. The association between smoking status and anthropometric outcomes was moderated by sedentary behavior, with current smokers evidencing higher BMI and WC at higher levels of sedentary behavior compared to lower levels of sedentary behavior. Results are discussed in terms of their implications for interventions, particularly with respect to postcessation weight gain.
Global Characterization of the SRC-1 Transcriptome Identifies ADAM22 as an ER-Independent Mediator of Endocrine-Resistant Breast Cancer
Authors: McCartan Damian , Bolger Jarlath C. , Fagan Aílis , Byrne Christopher , Hao Yuan , Qin Li , McIlroy Marie , Xu Jianming , Hill Arnold D. , Gaora Peadar Ó , Young Leonie S.
Published: November 2011

The development of breast cancer resistance to endocrine therapy results from an increase in cellular plasticity that permits the emergence of a hormone-independent tumor. The steroid coactivator protein SRC-1, through interactions with developmental proteins and other nonsteroidal transcription factors, drives this tumor adaptability. In this discovery study, we identified ADAM22, a non-protease member of the ADAM family of disintegrins, as a direct estrogen receptor (ER)-independent target of SRC-1. We confirmed SRC-1 as a regulator of ADAM22 by molecular, cellular, and in vivo studies. ADAM22 functioned in cellular migration and differentiation, and its levels were increased in endocrine resistant-tumors compared with endocrine-sensitive tumors in mouse xenograft models of human breast cancer. Clinically, ADAM22 was found to serve as an independent predictor of poor disease-free survival. Taken together, our findings suggest that SRC-1 switches steroid-responsive tumors to a steroid-resistant state in which the SRC-1 target gene ADAM22 has a critical role, suggesting this molecule as a prognostic and therapeutic drug target that could help improve the treatment of endocrine-resistant breast cancer. Cancer Res; 72(1); 220–9. ©2011 AACR.
Leflunomide Induces Apoptosis in Fludarabine-Resistant and Clinically Refractory CLL Cells
Authors: Dietrich Sascha , Krämer Oliver H. , Hahn Esther , Schäfer Claudia , Giese Thomas , Hess Michael , Tretter Theresa , Rieger Michael , Hüllein Jennifer , Zenz Thorsten , Ho Anthony D. , Dreger Peter , Luft Thomas
Published: November 2011

Purpose: Environmental conditions in lymph node proliferation centers protect chronic lymphocytic leukemia (CLL) cells from apoptotic triggers. This situation can be mimicked by in vitro stimulation with CD40 ligand (CD40L) and interleukin 4 (IL-4). Our study investigates the impact of the drug leflunomide to overcome apoptosis resistance of CLL cells.

Experimental Design: CLL cells were stimulated with CD40L and IL-4 and treated with fludarabine and the leflunomide metabolite A771726.

Results: Resistance to fludarabine-mediated apoptosis was induced by CD40 activation alone stimulating high levels of BCL-XL and MCL1 protein expression. Apoptosis resistance was further enhanced by a complementary Janus-activated kinase (JAK)/STAT signal induced by IL-4. In contrast, CLL proliferation required both a CD40 and a JAK/STAT signal and could be completely blocked by pan-JAK inhibition. Leflunomide (A771726) antagonized CD40L/IL-4–induced proliferation at very low concentrations (3 μg/mL) reported to inhibit dihydroorotate dehydrogenase. At a concentration of 10 μg/mL, A771726 additionally attenuated STAT3/6 phosphorylation, whereas apoptosis of CD40L/IL-4–activated (“resistant”) CLL cells was achieved with higher concentrations (IC50: 80 μg/mL). Apoptosis was also effectively induced by A771726 in clinically refractory CLL cells with and without a defective p53 pathway. Induction of apoptosis involved inhibition of NF-κB activity and loss of BCL-XL and MCL1 expression. In combination with fludarabine, A771726 synergistically induced apoptosis (IC50: 56 μg/mL).

Conclusion: We thus show that A771726 overcomes CD40L/IL-4–mediated resistance to fludarabine in CLL cells of untreated as well as clinically refractory CLL cells. We present a possible novel therapeutic principle for attacking chemoresistant CLL cells. Clin Cancer Res; 18(2); 417–31. ©2011 AACR.
A Combined Epigenetic Therapy Equals the Efficacy of Conventional Chemotherapy in Refractory Advanced Non–Small Cell Lung Cancer
Authors: Rodríguez-Paredes Manuel , Esteller Manel
Published: November 2011

A new study by Juergens and colleagues provides the first successful example of a combined epigenetic therapy capable of achieving results similar to those of conventional chemotherapy in refractory metastatic non–small cell lung cancer. Furthermore, the authors describe interesting blood-based DNA methylation biomarkers that may be useful in predicting clinical response. Cancer Discovery; 1(7); 557–9. ©2011 AACR.

Commentary on Juergens et al., p. 598.
Molecular Biomarker of Inflammatory Response Is Associated with Rebleeding in Spontaneous Intracerebral Hemorrhage
Authors: Wang Kuo-Wei , Cho Chung-Lung , Chen Han-Jung , Liang Cheng-Loong , Liliang Po-Chou , Tsai Yu-Duan , Wang Hao-Kuang , Lu Kang
Published: November 2011

Background and Purpose: Rebleeding in spontaneous intracerebral hemorrhage (ICH) is a major cause of morbidity and mortality among stroke survivors. Due to the links between inflammation and rebleeding, we hypothesized that the biomarkers of inflammation are associated with the pathogenesis of rebleeding in ICH. We sought to investigate whether these biomarkers and clinical variables on admission can provide prognostic information on the risk of rebleeding. Methods: This prospective study enrolled 59 consecutive patients with spontaneous ICH. We determined the concentrations of interleukin-10 (IL-10), intercellular adhesion molecule-1, and complement 3 in blood samples obtained on admission. Results: Univariate analysis indicated that hematoma volume, leukocyte count, hydrocephalus, and plasma IL-10 levels were associated with rebleeding. Multivariate logistic regression analysis indicated that hydrocephalus (95% CI of OR, 1.6–26.7) and IL-10 (95% CI of OR, 1.03–1.22) were independently associated with an increased probability of rebleeding. Conclusion: These data suggest that IL-10, a molecular biomarker of inflammatory response in the early acute phase of ICH, is associated with subsequent rebleeding.
Bronchoepithelial Expression of CXCR1 and CXCR2 Does Not Facilitate Transepithelial Migration of Neutrophils
Authors: Schulz Christian , Stoelcker Benjamin , Ruhland Brigitte , Jentsch Nico , Steege Andreas
Published: November 2011

Background: Neutrophilic airway inflammation is one of the key features of chronic obstructive pulmonary disease (COPD). The chemokine receptors 1 (CXCR1) and 2 (CXCR2) are expressed in the bronchial mucosa during chronic inflammation and might be of importance for transepithelial migration of neutrophils. Objectives: This study addressed the role of bronchoepithelial CXCR1 and CXCR2 expression with respect to transepithelial migration of neutrophils. Methods: Primary bronchial epithelial cells (PBECs) derived from COPD patients and healthy controls as well as transiently CXCR1- and CXCR2-transfected Calu-6 cells were used for transepithelial migration assays of neutrophils under various conditions. Epithelial CXCR1 and CXCR2 expression was verified by means of flow cytometry. Results: Transepithelial migration of neutrophils was significantly increased following lipopolysaccharide pretreatment of epithelial cells. Transient transfection of CXCR1 and CXCR2 neither augmented the transepithelial migration of neutrophils, nor did the selective blockade of CXCR1 and CXCR2 have any significant effect on neutrophilic transepithelial migration. In addition, no differences were found in PBECs and neutrophils derived from healthy controls and COPD patients. Conclusions: The data of the present study do not support the hypothesis that bronchoepithelial expression of CXCR1 and/or CXCR2 facilitate transepithelial migration of neutrophils.
The Initiation of Modern “Soft Snowball” and “Hard Snowball” Climates in CCSM3. Part I: The Influences of Solar Luminosity, CO2 Concentration, and the Sea Ice/Snow Albedo Parameterization
Authors: Yang Jun , Peltier W. Richard , Hu Yongyun
Published: November 2011

The “Snowball Earth” hypothesis, proposed to explain the Neoproterozoic glacial episodes in the period 750–580 million years ago, suggested that the earth was globally covered by ice/snow during these events. This study addresses the problem of the forcings required for the earth to enter such a state of complete glaciation using the Community Climate System Model, version 3 (CCSM3). All of the simulations performed to address this issue employ the geography and topography of the present-day earth and are employed to explore the combination of factors consisting of total solar luminosity, CO2 concentration, and sea ice/snow albedo parameterization that would be required for such an event to occur. The analyses demonstrate that the critical conditions beyond which runaway ice–albedo feedback will lead to global freezing include 1) a 10%–10.5% reduction in solar radiation with preindustrial greenhouse gas concentrations; 2) a 6% reduction in solar radiation with 17.5 ppmv CO2; or 3) 6% less solar radiation and 286 ppmv CO2 if sea ice albedo is equal to or greater than 0.60 with a snow albedo of 0.78, or if sea ice albedo is 0.58 with a snow albedo equal to or greater than 0.80. These bifurcation points are very sensitive to the sea ice and snow albedo parameterizations. Moreover, “soft Snowball” solutions are found in which tropical open water oceans stably coexist with year-round snow-covered low-latitude continents, implying that tropical continental ice sheets would actually be present. The authors conclude that a “soft Snowball” is entirely plausible, in which the global sea ice fraction may reach as high as 76% and sea ice margins may extend to 10°S(N) latitudes.
Soil Moisture Estimation Using Thermal Inertia: Potential and Sensitivity to Data Conditions
Authors: Matsushima Dai , Kimura Reiji , Shinoda Masato
Published: November 2011

Thermal inertia retrieval using a thermal infrared remote sensing technique has been examined as a possible method for estimating soil moisture. This method is an application of the theory that thermal inertia highly correlates with soil water content. This study shows a method for retrieving thermal inertia from a heat budget model of the earth’s surface using radiative surface temperatures, insolation, and meteorological data observed in field experiments. In bare to sparsely vegetated areas, this method has the potential to estimate subsurface soil moisture with a precision of ±3%–4% of the daily volumetric soil moisture content at a significance level of 5%, which is enough to roughly classify thermal inertia estimates into a few levels of soil moisture (e.g., wet, middle, and dry). The analysis also includes an examination of the practical performance of the thermal inertia estimation according to the temporal resolution of the data, assuming the use of satellite and routine meteorological data. It is found that the following combination of data can achieve the precision given above: radiative surface temperature from geostationary/multiple polar orbiting satellites, insolation retrieved from geostationary satellite data, and routine meteorological data.
Emergence of NK-cell progenitors and functionally competent NK-cell lineage subsets in the early mouse embryo
Authors: Tang Yanjuan , Peitzsch Claudia , Charoudeh Hojjatollah Nozad , Cheng Min , Chaves Patricia , Jacobsen Sten Eirik W. , Sitnicka Ewa
Published: November 2011

The earliest stages of natural killer (NK)–cell development are not well characterized. In this study, we investigated in different fetal hematopoietic tissues how NK-cell progenitors and their mature NK-cell progeny emerge and expand during fetal development. Here we demonstrate, for the first time, that the counterpart of adult BM Lin−CD122+NK1.1−DX5− NK-cell progenitor (NKP) emerges in the fetal liver at E13.5. After NKP expansion, immature NK cells emerge at E14.5 in the liver and E15.5 in the spleen. Thymic NK cells arise at E15.5, whereas functionally competent cytotoxic NK cells were present in the liver and spleen at E16.5 and E17.5, respectively. Fetal NKPs failed to produce B and myeloid cells but sustained combined NK- and T-lineage potential at the single-cell level. NKPs were also found in the fetal blood, spleen, and thymus. These findings show the emergence and expansion of bipotent NK/T-cell progenitor during fetal and adult lymphopoiesis, further supporting that NK/T-lineage restriction is taking place prethymically. Uncovering the earliest NK-cell developmental stages will provide important clues, helping to understand the origin of diverse NK-cell subsets, their progenitors, and key regulators.
Psychoanalysis, Secularism, and Sexuality
Authors: Watson Janell
Published: November 2011

In this interview, feminist historian Joan Wallach Scott discusses her first encounters with critical theory, the early days of teaching women's history, her turn to the history of the present, her work on the history of feminism, her book on the Muslim veil, and her current project on secularism. Scott was trained as a social historian of France, and her first book was The Glassworkers of Carmaux: French Craftsmen and Political Action in a Nineteenth-Century City. With Louise Tilly she authored Women, Work, and Family. As founding director of Brown University's Pembroke Center for Teaching and Research on Women, Scott participated in a feminist theory reading group with scholars such as Naomi Schor and Elizabeth Weed. Her seminal essay, “Gender: A Useful Category of Historical Analysis,” reflects this encounter with theory. At first her strongest theoretical influence was Michel Foucault. Her most recent work has taken the form of histories of the present, beginning with two genealogical studies of contemporary French feminism, Only Paradoxes to Offer and Parité! She only gradually became interested in Freud and Jacques Lacan. In Politics of the Veil, psychoanalysis proved useful in her analysis of the Muslim head-scarf controversies in French schools, and it plays an even more prominent role in her forthcoming book, The Fantasy of Feminist History. She recently led a seminar on secularism at the Institute for Advanced Study in Princeton, where she is on the faculty. She is currently interested in Freud, whom she reads as a secular theorist of sexuality.
One World in Relation
Authors: Diawara Manthia
Published: November 2011

In 2009, equipped with a camera, Manthia Diawara followed Édouard Glissant on the Queen Mary II in a transatlantic journey from South Hampton, United Kingdom, to Brooklyn, New York. This extraordinary voyage, six days and five nights, resulted in an intellectual biography in which Glissant elaborates on his theory of Relation and the concept of “Tout-monde.” This conversation is from that film: Édouard Glissant: One World in Relation (2009).
A Vigil of Departure
Authors: Martin Marilyn
Published: November 2011

This article, based on the catalogue of his 2010–11 retrospective exhibition, assesses Louis Khehla Maqhubela’s contribution to South African art. Born in Durban in 1939, Maqhubela also lived in Soweto and studied at Johannesburg’s Polly Street Art Centre. By winning the overall Artist of Fame and Promise Award in 1966, he became the first to cross the divide between black and white artists. The three months spent abroad as part of that prize enabled him to break out of the conventions of “township art,” and further change and new artistic directions followed his emigration first to Ibiza, then to London.
Probing White Guilt, Pursuing White Redemption: William Kentridge’s 9 Drawings for Projection
Authors: Erickson Peter
Published: November 2011

William Kentridge’s 9 Drawings for Projection present white characters in the context of apartheid caught between guilt and redemption, with special attention to the intermediate terrain. Felix in Exile, the fifth film, suggests that the dismantling of the structures of white racism requires a long-term excavation of the white psyche. The quest for whites’ full understanding of their apartheid legacy is tricky because of the fine line between self-examination and self-absorption. The later films beautifully dramatize the vulnerability of white characters as they cross the line and blur crucial distinctions. Kentridge’s call for a political art of “ambiguity, contradiction, uncompleted gestures and uncertain endings” has great integrity but may also condone insufficiency and may itself need scrutiny and revision.