bluuebunny/crossref_metadata_2025 huggingface dataset:
Testing the variation of fundamental constants with astrophysical and spectroscopic data1This review is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.
Authors: Olive Keith A.
Published: May 2011

In many theories of unified interactions, there are additional degrees of freedom that may allow for the variation of the fundamental constants of nature. I will review the motivation for and theoretical relations between such variations. I will then review the various astrophysical and experimental constraints on the variations of constants and their dependence on spectroscopic data.
High accuracy radiative data for plasma opacities1This article is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.
Authors: Nahar Sultana N.
Published: May 2011

Opacity, which gives the measure of the radiation transport in plasmas, is caused by the repeated absorption and emission of the propagating radiation by the constituent plasma elements. Microscopically, opacity (κ) depends mainly on two radiative processes: (i) photo-excitation (bound-bound transition) and (ii) photo-ionization (bound-free transition) in addition to electron-photon scattering. The monochromatic opacity κ(ν) at photon frequency ν is determined by the atomic parameters, oscillator strengths (f), and photo-ionization cross sections (σPI). However, total monochromatic opacity is obtained from summed contributions of all possible transitions from all ionization stages of all elements in the source. The calculation of accurate parameters for such a large number of transitions has been the main problem for obtaining accurate opacities. The overall mean opacity, such as the Rosseland mean opacity (κR), depends also on the physical conditions, such as temperature, density, elemental abundances, and equation of state. The necessity for high-precision calculations for opacities may be exemplified by the existing problems, such as the determination of solar elemental abundances. With new computational developments under the Iron Project, we are able to calculate more accurate atomic parameters, such as oscillator strengths for large number of transitions using the relativistic Breit–Pauli R-matrix (BPRM) method. We are finding new features in photo-ionization, such as the existence of extensive and dominant resonant structures in the high-energy region not studied before. These new data should provide more accurate opacities in high-temperature plasmas and can be used to investigate the well-known solar abundance problem.
Laboratory measurements of oscillator strengths and their astrophysical applications1This review is part of a Special Issue on the 10th International Colloquium on Atomic Spectra and Oscillator Strengths for Astrophysical and Laboratory Plasmas.
Authors: Pickering J.C. , Blackwell-Whitehead R. , Thorne A.P. , Ruffoni M. , Holmes C.E.
Published: May 2011

We present an overview of current needs for accurate laboratory atomic transition probabilities (log(gf)) for astrophysical applications, particularly for iron group element spectra in the IR, optical, UV, and VUV spectral regions. Examples are given of our recent measurements, undertaken using the combination of high-resolution Fourier transform spectrometry and time-resolved laser-induced fluorescence. Laboratory measured log(gf) values are particularly important for the determination of elemental abundances in astrophysical objects. Advances in astronomical instrumentation, particularly access to underexplored regions (IR, vacuum UV,VUV), require improved accuracy and completeness of the atomic database for meaningful analyses of astrophysical spectra.
Two-pile interaction factor revisited
Authors: Chen S.L. , Song C.Y. , Chen L.Z.
Published: May 2011

A rigorous analytical method is developed for calculating the interaction factor between two identical piles subjected to vertical loads. Following the scheme proposed by Muki and Sternberg, the problem is formulated by decomposing the pile soil system into an extended soil mass and two fictitious piles. With the consideration of the compatibility condition that the axial strain of the fictitious pile be equal to the corresponding strain average over the extended soil, a Fredholm integral equation of the second kind governing the unknown axial forces along fictitious piles is established and then solved using numerical procedures. The real pile head settlement is subsequently calculated based on the determined fictitious pile forces and finally, the desired pile interaction factor is derived. Comparison with existing solutions confirms that the conventional interaction factor approach does tend to overestimate the interaction and may cause considerable errors for long compressible piles. Numerical results for the interaction factor between two piles in both semi-infinite and finite layered soils are presented over a wide range of pile and soil parameters, and also the settlement behaviour of a 3 × 3 pile group embedded in a semi-infinite soil is studied by virtue of the newly established interaction factor.
An empirical model for the evaluation of the degree of saturation of shallow soils in relation to rainfalls
Authors: Valentino Roberto , Montrasio Lorella , Losi Gian Luca , Bittelli Marco
Published: May 2011

The evaluation of shallow soils water content is very important in many fields, and different hydrological models are widely applied to simulate field-scale water flow and soil water content. The degree of saturation of a shallow soil is a time-varying variable, depending on different weather conditions. In many applications, it is useful to directly correlate the soil degree of saturation to time series of rainfall amount. This paper presents a simplified empirical model, which allows for computation of the soil degree of saturation using readily available climate data on air temperature and rainfall depths. The model is tested with in situ measurements of soil water content collected at three sites in the Emilia Romagna region in northern Italy. The experimental data are compared with the results obtained from the simplified model over an observation period of almost 5 years. The model has been used to generate soil water content time series at different depths and requires a separate calibration for each depth where the degree of saturation is computed. A discussion on the model’s calibration is also carried out to clarify the model sensitivity to the different parameters and the choice of input data.
Measured performance of a 26 m deep top-down excavation in downtown Shanghai
Authors: Tan Yong , Li Mingwen
Published: May 2011

Via a long-term comprehensive instrumentation program, the performance of a 26 m deep metro station excavation constructed by the top-down method in downtown Shanghai was extensively examined. The measured excavation responses included diaphragm wall deflections, wall settlements, ground settlements, uplifts of interior steel columns, axial forces of propping struts, groundwater table levels, and settlements of adjacent buildings and utility pipelines. Based on the analyses of field data, the following major findings were obtained: (i) the concrete struts along with the floor slabs effectively suppressed later wall movements and consequently reduced the chance that the maximum wall deflections would occur above the excavation surfaces, (ii) with the progress of excavation to a lower depth, the diaphragm walls underwent a serrated settlement pattern over time, (iii) no significant post-excavation wall deflection occurred, (iv) the relationship between the interior column uplifts and the maximum wall deflections can be described by a linear equation, and (v) most system loads due to soil removal were carried by the concrete struts along with the floor slabs. The struts sustained mainly the released earth pressures due to the exposure of the adjacent portions of diaphragm walls, and the soil removal distant from the struts imposed limited effects on the strut axial forces.
Passive earth-pressure coefficients by upper-bound numerical limit analysis
Authors: Antão Armando N. , Santana Teresa G. , Vicente da Silva Mário , da Costa Guerra Nuno M.
Published: May 2011

A three-dimensional (3D) numerical implementation of the limit analysis upper-bound theorem is used to determine passive horizontal earth-pressure coefficients. An extension technique allowing determination of the 3D passive earth pressures for any width-to-height ratios greater than 7 is presented. The horizontal passive earth-pressure coefficients are presented and compared with solutions published previously. Results of the ratio between the 3D and two-dimensional horizontal passive earth-pressure coefficients are shown and found to be almost independent of the soil-to-wall friction ratio. A simple equation is proposed for calculating this passive earth-pressure ratio.
Field monitoring and analysis of twin 3660 mm inside diameter induced trench culverts installed under 21.7 m of fill
Authors: McGuigan Benjamin L. , Valsangkar Arun J.
Published: May 2011

Although several induced trench field instrumentations have been reported in the literature, none have been for twin culverts. This paper describes a field instrumentation of twin 3660 mm inside diameter concrete culverts installed in an induced trench under 21.7 m of fill. Earth pressures were measured at the crown, shoulder, springline, haunch, and invert locations. Average earth pressures measured at the crown and springline were 0.67 and 0.32 times the overburden, respectively. Due to the large culvert size, proper compaction in the haunch regions was not achieved and the bedding was lightly compacted for constructability reasons. These factors resulted in high earth pressures at the inverts (greater than approximately 1400 kPa) and low pressures at the haunches (32–165 kPa). Numerical modelling was used to determine a vertical earth load of 0.87 times the soil prism load. The twin induced trench condition resulted in vertical earth loads 6% higher and 30% lower than the single induced trench and twin positive projecting conditions, respectively. The induced trench method therefore appears to be a viable installation option for large-diameter twin culverts, provided that issues related to bedding and constructability are addressed.
EMBODIED CONCEPT DISCOVERY THROUGH QUALITATIVE ACTION MODELS
Authors: KOŠMERLJ ALJAŽ , BRATKO IVAN , ŽABKAR JURE
Published: May 2011

We present a novel approach to embodied learning of qualitative models. We introduce algorithm STRUDEL that enables an autonomous robot to discover new concepts by performing experiments in its environment. The robot collects data about its actions and its observations of the environment. From the obtained data, the robot learns qualitative descriptive models of the effects that its actions have in the environment. Models are learned using inductive logic programming. We describe two experiments with a humanoid robot Nao in which Nao learns descriptive qualitative models which contain what can be interpreted as simple definitions of the concepts of movability and stability.
FUZZY QUALITATIVE LINK ANALYSIS FOR ACADEMIC PERFORMANCE EVALUATION
Authors: BOONGOEN TOSSAPON , SHEN QIANG , PRICE CHRIS
Published: May 2011

Many approaches have been developed for academic performance evaluation using various fuzzy techniques. Initial methods rely greatly on experts' specification of analytical parameters, without making use of valuable information embedded in collected data. Given this insight, fuzzy rule induction has recently been studied as a data-driven alternative. Despite its efficiency and reported performance, the fuzzy subsethood metric representing the strength of relations between system variables is only used at a coarse level, with the underlying semantics being unfortunately distorted via a local re-scaling scheme. To overcome this problem, a novel fuzzy classification system is introduced in this paper, in which the existing measure is used to its full potential via the methodology of qualitative link analysis. With a network representation where variables and their relations are encoded as graph nodes and edges, the classification of a new instance conceptually becomes a problem of link-based similarity estimation that can be effectively resolved using the proposed fuzzy qualitative model. This new approach has been evaluated against the existing rule-based method, revealing significant advantages of the present work.
AN INVERTING CIRCUMFERENTIAL SUTURE FOR FLEXOR TENORRAPHY
Authors: Sullivan P. J. , Hirpara K. M. , Healy C. E. , Dockery P. , Kelly J. L.
Published: May 2011

Zone two flexor tendon repair remains challenging with significant outcome variation using recognised techniques. Tendon adhesion formation results in poor outcomes and rehabilitation regimes aim to limit this. Some repairs augment strength, but increasing bulk mitigates against movement. This novel epitendinous technique causes tendon inversion with potential gliding benefits and improved outcomes.

60 porcine tendons were randomised to a 2-stranded modified Kessler or a 4-stranded Adelaide repair, then sudivided into three different circumferential technique groups: locked running, Silfverskiold, or a new inverting repair. Tendon load to failure (LTF), 2 mm gap formation, bulking effect and method of failure were analysed during digital tensiometry.

Four-stranded repairs demonstrated better LTF than 2-stranded techniques. The inverting epitendinous and Silfverskiold repairs showed higher LTF characteristics than the locked running suture, and better tissue holding capacity.

The inverting repair has similar properties to commonly used suturing methods and the conformation creates a smooth inverted repair.
INTRAMEDULLARY FIXATION OF PROXIMAL PHALANGEAL FRACTURES THROUGH A VOLAR EXTRA-TENDON SHEATH APPROACH
Authors: Itadera Eichi , Oikawa Yasuhiro , Shibayama Masataka , Kobayashi Tomoko , Moriya Hideshige
Published: May 2011

We present an operative technique and the results of intramedullary fixation of proximal phalangeal shaft fractures through a volar extra-tendon sheath approach. A J-shaped nail, which is a curved Kirschner wire sharply bent at the proximal end, was inserted from the palmar aspect of the proximal phalangeal base. Six fingers of the six patients (all male) were treated with this method. The mean age of the patients was 51 years (range, 20–69 years). There were four open and two closed fractures. All fingers attained successful fracture union and one of them had correction loss. No patient complained of pain at the final follow-up, and the average of total active motion was 223° (190° – 255°). This method may be an alternative for treatments of the proximal phalangeal shaft fractures because of its less invasive nature, although it does not offer anatomical reduction.
SURGICAL TREATMENT OF NEUROGENIC THORACIC OUTLET SYNDROME SECONDARY TO THE CLAVICLE HAEMATOGENIC SUBACUTE OSTEOMYELITIS
Authors: Kapickis Martins , Lahiri Amitabha , Pupelis Guntars
Published: May 2011

A rare case of neurogenic thoracic outlet syndrome secondary to subacute osteomyelitis (SOM) of clavicle is presented. It was treated successfully with scalenectomy combined with clavicle and first rib resection and reconstruction of the clavicle using vascularised seventh rib transfer. Various issues involved in the diagnosis and management of such a case are discussed.
OSTEOCHONDROMA OF THE LUNATE WITH EXTENSOR TENDONS RUPTURE OF THE INDEX FINGER: A CASE REPORT
Authors: Katayama Takeshi , Ono Hiroshi , Furuta Kazuhiro
Published: May 2011

Osteochondroma rarely develops from the carpal bones. We report a first case in which a dorsal osteochondroma of the lunate caused attritional rupture of the tendon of the extensor indicis proprius and a tendon of the extensor digitorum communis of index finger.
SPONTANEOUS ULNAR DISLOCATION OF THE INDEX, LONG, RING AND SMALL FINGER EXTENSOR TENDONS AT THE METACARPOPHALANGEAL JOINTS: A CASE REPORT
Authors: Tanabe Katsuhisa , Nakajima Takaya , Sogo Eiji
Published: May 2011

Finger extensor tendon dislocation at the metacarpophalangeal joint is caused by various etiologies, such as trauma, congenital anomaly, or rheumatoid arthritis. When the dislocation occurs with no etiology, this is called spontaneous dislocation. Although spontaneous extensor tendon dislocation in one, two or three fingers has been described, to our knowledge, simultaneous dislocation in four fingers has not been reported. In this paper, we report a spontaneous ulnar dislocation of all the extensor tendons in the index, long, ring, and small fingers. Repair of the radial sagittal bands of the extensor digitorum communis of the middle and ring fingers reduced dislocation of all the extensor tendons in four fingers.
LOCKED METACARPOPHALANGEAL JOINT OF THE LITTLE FINGER DUE TO HYPEREXTENSION INJURY: A CASE REPORT
Authors: Ikeda Masayoshi , Kobayashi Yuka , Saito Ikuo , Oka Yoshinori
Published: May 2011

We treated a rare case of locked metacarpophalangeal joint of the little finger due to a hyperextension injury. The mechanism of the occurrence was considered to be closely similar to those that happened in the thumb, and the locking was successfully released by a manual reduction without complication.
AVULSION OF FLEXOR DIGITORUM PROFUNDUS SECONDARY TO RECURRENT ENCHONDROMA
Authors: Nomura T. , Nakamura T. , Sato K. , Toyama Y. , Ikegami H.
Published: May 2011

We report a case of avulsion of the flexor digitorum profundus secondary to recurrent enchondroma. The tumor was curetted with bone grafting of cancellous bone from the distal radius, and the fragment avulsed by the flexor digitorum profundus tendon was fixed to its original site using a pullout suture through the distal phalanx to the nail. The lesion healed and function recovered 6 years after surgery.
OSTEOCUTANEOUS RADIAL FOREARM FREE FLAPS: PROPHYLACTIC FIXATION OF DONOR SITE USING LOCKING PLATE AUGMENTED WITH MINERAL CEMENT
Authors: Ya'ish F. , Waton A. , B'Durga H. , Nanu A.
Published: May 2011

Prophylactic plating of donor site in osteocutaneous radial forearm free flaps have demonstrated improvement in fracture rates. Previous series used conventional plating systems which rely on plate-bone friction forces to generate stability and can result in iatrogenic fractures if not accurately contoured. Locking plates have superior stability and do not require contouring. This retrospective series reports our experience using locking plate fixation augmented with calcium phosphate mineral cement. Twenty patients' records were reviewed; 13 were alive and reviewed clinically. Mean radiological follow-up was 28.2 months. Two deceased patients had donor site fractures diagnosed on the first postoperative radiograph. These fractures were related to technical fixation errors and failure to apply correct locking fixation principles. None of the other patients with proper locking fixation had fractures or metalwork related complications. We believe that locking fixation augmented with mineral cement can provide more biological stability and enhance restoration of bone structural strength.
NOVEL AND COST-EFFECTIVE SYNTHESIS OF SILVER NANOCRYSTALS: A GREEN SYNTHESIS
Authors: ARSHI NISHAT , AHMED FAHEEM , ANWAR M. S. , KUMAR SHALENDRA , KOO BON HEUN , LU JUNQING , LEE CHAN GYU
Published: May 2011

This paper reports the study on the synthesis and characterization of silver nanocrystals by a two-step synthesis procedure. The first step is the solution-free hand grinding of silver foil and sugar at room temperature for few minutes. The second step is the thermal decomposition of silver/sugar composite to form silver nanocrystals. The as-synthesized silver nanocrystals were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet visible (UV/Vis) spectroscopy, atomic force microscopy (AFM) and transmission electron microscopy (TEM) studies. The XRD pattern showed a face-centered cubic structure (single phase) with high crystallinity. The lattice parameters calculated from XRD pattern were found to be a = 4.12 Å for silver nanocrystals with average grain size of ~ 19 nm. The energy dispersive analysis of X-rays (EDAX) of silver nanocrystals confirmed the presence of silver and no peak of any secondary phase was detected. FESEM and AFM studies showed that the crystals have cube-like morphology. TEM results showed that the size of silver nanocrystals was found to be ~ 22 nm. This novel synthesis route, not reported earlier, would be a promising candidate for a variety of future applications of silver nanocrystals.
CHROMIUM-RICH COATINGS WITH WS2 NANOPARTICLES CONTAINING FULLERENE-LIKE STRUCTURE
Authors: EIDELMAN O. , FRIEDMAN H. , ROSENTSVEIG R. , MOSHKOVITH A. , PERFILIEV V. , COHEN S. R. , FELDMAN Y. , RAPOPORT L. , TENNE R.
Published: May 2011

In this work chromium-rich coatings impregnated with fullerene-like (IF)-WS2 nanoparticles were deposited on stainless steel substrates. The coatings were obtained from a trivalent chromium bath at pH 2 by galvanostatic electrodeposition. Zinc and cobalt salts were added to the aqueous solution in small amounts serving as cationic growth promoters. Photodeposition of tin-palladium nanoparticles was used as seeding enhancer for the co-deposition of the fullerene-like nanoparticles. The coatings were characterized by a number of techniques and were found to show a decreasing gradient of the IF nanoparticles towards the film-substrate interface. Tribological tests showed that in contrast to the substrate and the pure metal coating, the IF-containing films exhibit low friction and wear.
EFFECT OF Co3O4 NANOPARTICLE ON THE PROPERTY OF BARIUM TITANATE CERAMIC
Authors: VITTAYAKORN W. C. , BUNJONG D. , RUANGPHANIT A. , VITTAYAKORN N.
Published: May 2011

Effects of the Co3O4 nanoparticle on the phase formation, microstructure and dielectric properties of barium titanate ceramics are investigated in this study. Co3O4 -doped BaTiO3 ceramics were prepared by the conventional mixed oxide method followed by normal sintering in air. Systematic studies of X-ray diffraction (XRD), scanning electron microscopy and dielectric spectroscopy with varying doping levels were performed. The cell parameters, tetragonality and crystallite size of doped ceramics also were calculated from XRD data. Results showed that the single phase of BaTiO3 gave no evidence of unwanted peak forms in any of the samples. Cubic phase occurred after adding Co3O4 at 0.25 mol%. Various grain sizes and shapes were found in this system. Finally, adding Co3O4 in BaTiO3 ceramics resulted in shifting of the Curie point to a lower temperature. The composition, x = 0.25, showed different dielectric behavior, which related to appearance of the cubic phase and fine grain microstructure.
Moving Picture Recording and Observation of Visible Femtosecond Light Pulse Propagation
Authors: Kakue Takashi , Aihara Masayuki , Takimoto Tetsuya , Awatsuji Yasuhiro , Nishio Kenzo , Ura Shogo , Kubota Toshihiro
Published: May 2011

We succeeded in recording and observing a spatially and temporally continuous moving picture of visible femtosecond light pulse propagation by using light-in-flight recording by holography, for the first time. We applied second-harmonic generation (SHG) to a NIR femtosecond light pulse from a mode-locked Ti:sapphire laser to generate a visible femtosecond light pulse. The center wavelength and duration of the generated light pulse were 400 nm and ∼100 fs, respectively. We acquired a moving picture of a visible and collimated femtosecond light pulse that propagated on a diffuser plate for 145 ps.
Fabrication and Piezoelectric Property of Highly Textured CaBi2Nb2O9 Ceramics by Tape Casting
Authors: Chen Huanbei , Fu Fang , Zhai Jiwei
Published: May 2011

Textured high-Curie-point lead-free piezoelectric ceramics, CaBi2Nb2O9 (CBN), were prepared by the tape casting method. Highly textured ceramics with a single phase and 95% Lotgering factor were obtained by the templated grain growth (TGG) technique. The textured CBN ceramics had a higher piezoelectric constant (d
33 = 17.8 pC/N) than their non textured counterparts (d
33 = 6.2 pC/N) prepared by a conventional solid-state sintering process. Furthermore, they had excellent thermostable of piezoelectric properties from room temperature to near Curie temperature. This type of textured CBN ceramic that can be prepared using the low-cost and scalable tape casting technique should be a promising candidate for high-temperature piezoelectric applications.
Intestinal SR-BI is upregulated in insulin-resistant states and is associated with overproduction of intestinal apoB48-containing lipoproteins
Authors: Hayashi Amanda A. , Webb Jennifer , Choi Joanna , Baker Chris , Lino Marsel , Trigatti Bernardo , Trajcevski Karin E. , Hawke Thomas J. , Adeli Khosrow
Published: May 2011

Intestinal lipid dysregulation is a common feature of insulin-resistant states. The present study investigated alterations in gene expression of key proteins involved in the active absorption of dietary fat and cholesterol in response to development of insulin resistance. Studies were conducted in two diet-induced animal models of insulin resistance: fructose-fed hamster and high-fat-fed mouse. Changes in the mRNA abundance of lipid transporters, adenosine triphosphate cassette (ABC) G5, ABCG8, FA-CoA ligase fatty acid translocase P4, Niemann-Pick C1-Like1 (NPC1L1), fatty acid transport protein 4 (FATP4), and Scavenger Receptor Class B Type I (SR-BI), were assessed in intestinal fragments (duodenum, jejunum, and ileum) using quantitative real-time PCR. Of all the transporters evaluated, SR-B1 showed the most significant changes in both animal models examined. A marked stimulation of SR-B1 expression was observed in all intestinal segments examined in both insulin-resistant animal models. The link between SR-BI expression and intestinal lipoprotein production was then examined in the Caco-2 cell model. SR-B1 overexpression in Caco-2 cells increased apolipoprotein B (apoB) 100 and apoB48 secretion, whereas RNAi knock down of SR-B1 decreased secretion of both apoB100 and apoB48. We also observed changes in subcellular distribution of SR-B1 in response to exogenous lipid and insulin. Confocal microscopy revealed marked changes in SR-BI subcellular distribution in response to both exogenous lipids (oleate) and insulin. In summary, marked stimulation of intestinal SR-BI occurs in vivo in animal models of diet-induced insulin resistance, and modulation of SR-BI in vitro regulates production of apoB-containing lipoprotein particles. We postulate that apical and/or basolateral SR-BI may play an important role in intestinal chylomicron production and may contribute to chylomicron overproduction normally observed in insulin-resistant states.
Early neural responses to strength training
Authors: Selvanayagam Victor S. , Riek Stephan , Carroll Timothy J.
Published: May 2011

The neural adaptations that accompany strength training have yet to be fully determined. Here we sought to address this topic by testing the idea that strength training might share similar mechanisms with some forms of motor learning. Since ballistic motor learning is accompanied by a shift in muscle twitches induced by transcranial magnetic stimulation (TMS) toward the training direction, we sought to investigate if these changes also occur after single isometric strength training sessions with various contraction duration and rate of force development characteristics (i.e., brief or sustained ballistic contractions or slow, sustained contractions). Twitch force resultant vectors and motor-evoked potentials (MEPs) induced by TMS were measured before and after single sessions of strength training involving the forearm muscles. Participants ( n = 12) each performed three training protocols (each consisting of 4 sets of 10 repetitions) and served as their own control in a counterbalanced order. All three training protocols caused a significant ( P < 0.05) shift in TMS-induced twitch force resultant vectors toward the training direction, followed by a gradual shift back toward the pretraining direction. The strongest effect was found when training involved both ballistic and sustained force components. There were no large or consistent changes in the direction of twitches evoked by motor nerve stimulation for any of the three training protocols. We suggest that these early neural responses to strength training, which share similar corticospinal changes to motor learning, might reflect an important process that precedes more long-term neural adaptation that ultimately enhance strength.
Hypoxic exercise training causes erythrocyte senescence and rheological dysfunction by depressed Gardos channel activity
Authors: Mao Tso-Yen , Fu Li-Lan , Wang Jong-Shyan
Published: May 2011

Despite enhancing cardiopulmonary and muscular fitness, the effect of hypoxic exercise training (HE) on hemorheological regulation remains unclear. This study investigates how HE modulates erythrocyte rheological properties and further explores the underlying mechanisms in the hemorheological alterations. Twenty-four sedentary males were randomly divided into hypoxic (HE; n = 12) and normoxic (NE; n = 12) exercise training groups. The subjects were trained on 60% of maximum work rate under 15% (HE) or 21% (NE) O2condition for 30 min daily, 5 days weekly for 5 wk. The results demonstrated that HE 1) downregulated CD47 and CD147 expressions on erythrocytes, 2) decreased actin and spectrin contents in erythrocytes, 3) reduced erythrocyte deformability under shear flow, and 4) diminished erythrocyte volume changed by hypotonic stress. Treatment of erythrocytes with H2O2that mimicked in vivo prooxidative status resulted in the cell shrinkage, rigidity, and phosphatidylserine exposure, whereas HE enhanced the eryptotic responses to H2O2. However, HE decreased the degrees of clotrimazole to blunt ionomycin-induced shrinkage, rigidity, and cytoskeleton breakdown of erythrocytes, referred to as Gardos effects. Reduced erythrocyte deformability by H2O2was inversely related to the erythrocyte Gardos effect on the rheological function. Conversely, NE intervention did not significantly change resting and exercise erythrocyte rheological properties. Therefore, we conclude that HE rather than NE reduces erythrocyte deformability and volume regulation, accompanied by an increase in the eryptotic response to oxidative stress. Simultaneously, this intervention depresses Gardos channel-modulated erythrocyte rheological functions. Results of this study provide further insight into erythrocyte senescence induced by HE.
PKB signaling and atrogene expression in skeletal muscle of aged mice
Authors: Gaugler Megan , Brown Alicia , Merrell Erin , DiSanto-Rose Maria , Rathmacher John A. , Reynolds Thomas H.
Published: May 2011

The purpose of this study was to determine if PKB signaling is decreased and contractile protein degradation is increased in extensor digitorum longus (EDL) and soleus (SOL) muscles from middle-aged (MA) and aged (AG) mice. We also examined the effect of age on atrogene expression in quadriceps muscle. PKB activity, as assessed by Thr308and Ser473phosphorylation, was significantly higher in EDL and SOL muscles from AG than MA mice. The age-related increase in PKB activity appears to be due to an increase in expression of the kinase, as PKB-α and PKB-β levels were significantly higher in EDL and SOL muscles from AG than MA mice. The phosphorylation of forkhead box 3a (FOXO3a) on Thr32, a PKB target, was significantly higher in EDL muscles from AG than MA mice. The rate of contractile protein degradation was similar in EDL and SOL muscles from AG and MA mice. Atrogin-1 and muscle-specific RING finger protein 1 (MuRF-1) mRNA levels did not change in muscles from AG compared with MA mice, indicating that ubiquitin-proteasome proteolysis does not contribute to sarcopenia. A significant decrease in Bcl-2 and 19-kDa interacting protein 3 (Bnip3) and GABA receptor-associated protein 1 (Gabarap1) mRNA was observed in muscles from AG compared with MA mice, which may contribute to age-related contractile dysfunction. In conclusion, the mechanisms responsible for sarcopenia are distinct from experimental models of atrophy and do not involve atrogin-1 and MuRF-1 or enhanced proteolysis. Finally, a decline in autophagy-related gene expression may provide a novel mechanism for impaired contractile function and muscle metabolism with advancing age.
Less is more: standard warm-up causes fatigue and less warm-up permits greater cycling power output
Authors: Tomaras Elias K. , MacIntosh Brian R.
Published: May 2011

The traditional warm-up (WU) used by athletes to prepare for a sprint track cycling event involves a general WU followed by a series of brief sprints lasting ≥50 min in total. A WU of this duration and intensity could cause significant fatigue and impair subsequent performance. The purpose of this research was to compare a traditional WU with an experimental WU and examine the consequences of traditional and experimental WU on the 30-s Wingate test and electrically elicited twitch contractions. The traditional WU began with 20 min of cycling with a gradual intensity increase from 60% to 95% of maximal heart rate; then four sprints were performed at 8-min intervals. The experimental WU was shorter with less high-intensity exercise: intensity increased from 60% to 70% of maximal heart rate over 15 min; then just one sprint was performed. The Wingate test was conducted with a 1-min lead-in at 80% of optimal cadence followed by a Wingate test at optimal cadence. Peak active twitch torque was significantly lower after the traditional than experimental WU (86.5 ± 3.3% vs. 94.6 ± 2.4%, P < 0.05) when expressed as percentage of pre-WU amplitude. Wingate test performance was significantly better ( P < 0.01) after experimental WU (peak power output = 1,390 ± 80 W, work = 29.1 ± 1.2 kJ) than traditional WU (peak power output = 1,303 ± 89 W, work = 27.7 ± 1.2 kJ). The traditional track cyclist's WU results in significant fatigue, which corresponds with impaired peak power output. A shorter and lower-intensity WU permits a better performance.
Primary ciliary dyskinesia: evaluation using cilia beat frequency assessment via spectral analysis of digital microscopy images
Authors: Olm Mary A. K. , Kögler João E. , Macchione Mariangela , Shoemark Amelia , Saldiva Paulo H. N. , Rodrigues Joaquim C.
Published: May 2011

Ciliary beat frequency (CBF) measurements provide valuable information for diagnosing of primary ciliary dyskinesia (PCD). We developed a system for measuring CBF, used it in association with electron microscopy to diagnose PCD, and then analyzed characteristics of PCD patients.1The CBF measurement system was based on power spectra measured through digital imaging. Twenty-four patients suspected of having PCD (age 1–19 yr) were selected from a group of 75 children and adolescents with pneumopathies of unknown causes. Ten healthy, nonsmoking volunteers (age ≥17 yr) served as a control group. Nasal brush samples were collected, and CBF and electron microscopy were performed. PCD was diagnosed in 12 patients: 5 had radial spoke defects, 3 showed absent central microtubule pairs with transposition, 2 had outer dynein arm defects, 1 had a shortened outer dynein arm, and 1 had a normal ultrastructure. Previous studies have reported that the most common cilia defects are in the dynein arm. As expected, the mean CBF was higher in the control group ( P < 0.001) and patients with normal ultrastructure ( P < 0.002), than in those diagnosed with cilia ultrastructural defects (i.e., PCD patients). An obstructive ventilatory pattern was observed in 70% of the PCD patients who underwent pulmonary function tests. All PCD patients presented bronchial wall thickening on chest computed tomography scans. The protocol and diagnostic techniques employed allowed us to diagnose PCD in 16% of patients in this study.
High-fat diet overrules the effects of training on fiber-specific intramyocellular lipid utilization during exercise
Authors: Van Proeyen Karen , Szlufcik Karolina , Nielens Henri , Deldicque Louise , Van Dyck Raf , Ramaekers Monique , Hespel Peter
Published: May 2011

In this study, we compared the effects of endurance training in the fasted state (F) vs. the fed state [ample carbohydrate intake (CHO)] on exercise-induced intramyocellular lipid (IMCL) and glycogen utilization during a 6-wk period of a hypercaloric (∼+30% kcal/day) fat-rich diet (HFD; 50% of kcal). Healthy male volunteers (18–25 yrs) received a HFD in conjunction with endurance training (four times, 60–90 min/wk) either in F ( n = 10) or with CHO before and during exercise sessions ( n = 10). The control group ( n = 7) received a HFD without training and increased body weight by ∼3 kg ( P < 0.001). Before and after a HFD, the subjects performed a 2-h constant-load bicycle exercise test in F at ∼70% maximal oxygen uptake rate. A HFD, both in the absence (F) or presence (CHO) of training, elevated basal IMCL content by ∼50% in type I and by ∼75% in type IIa fibers ( P < 0.05). Independent of training in F or CHO, a HFD, as such, stimulated exercise-induced net IMCL breakdown by approximately twofold in type I and by approximately fourfold in type IIa fibers. Furthermore, exercise-induced net muscle glycogen breakdown was not significantly affected by a HFD. It is concluded that a HFD stimulates net IMCL degradation by increasing basal IMCL content during exercise in type I and especially IIa fibers. Furthermore, a hypercaloric HFD provides adequate amounts of carbohydrates to maintain high muscle glycogen content during training and does not impair exercise-induced muscle glycogen breakdown.
Inhibition of Histone Lysine Methylation Enhances Cancer–Testis Antigen Expression in Lung Cancer Cells: Implications for Adoptive Immunotherapy of Cancer
Authors: Rao Mahadev , Chinnasamy Nachimuthu , Hong Julie A. , Zhang Yuwei , Zhang Mary , Xi Sichuan , Liu Fang , Marquez Victor E. , Morgan Richard A. , Schrump David S.
Published: May 2011

Cancer–testis antigens (CTA), such as NY-ESO-1, MAGE-A1, and MAGE-A3, are immunogenic proteins encoded by genes, which are normally expressed only in male germ cells but are activated by ill-defined epigenetic mechanisms in human tumors, including lung cancers. Previously, we reported induction of these CTAs in cancer cells, but not normal cells, by DNA-demethylating agents and histone deacetylase inhibitors using clinically achievable exposure conditions. In the present study, we evaluated chromatin alterations associated with repression/activation of cancer–testis genes in lung cancer cells to further develop gene-induction regimens for cancer immunotherapy. Repression of NY-ESO-1, MAGE-A1, and MAGE-A3 coincided with DNA hypermethylation, recruitment, and binding of polycomb-group proteins, and histone heterochromatin modifications within the promoters of these genes. Derepression coincided with DNA demethylation, dissociation of polycomb proteins, and presence of euchromatin marks within the respective promoters. Short hairpin RNAs were used to inhibit several histone methyltransferases (KMT) and histone demethylases (KDM) that mediate histone methylation and repress gene expression. Knockdown of KMT6, KDM1, or KDM5B markedly enhanced deoxyazacytidine (DAC)-mediated activation of these cancer–testis genes in lung cancer cells. DZNep, a pharmacologic inhibitor of KMT6 expression, recapitulated the effects of KMT6 knockdown. Following DAC–DZNep exposure, lung cancer cells were specifically recognized and lysed by allogeneic lymphocytes expressing recombinant T-cell receptors recognizing NY-ESO-1 and MAGE-A3. Combining DNA-demethylating agents with compounds, such as DZNep, that modulate histone lysine methylation may provide a novel epigenetic strategy to augment cancer–testis gene expression as an adjunct to adoptive cancer immunotherapy. Cancer Res; 71(12); 4192–204. ©2011 AACR.
Tumor Galectin-1 Mediates Tumor Growth and Metastasis through Regulation of T-Cell Apoptosis
Authors: Banh Alice , Zhang Jing , Cao Hongbin , Bouley Donna M. , Kwok Shirley , Kong Christina , Giaccia Amato J. , Koong Albert C. , Le Quynh-Thu
Published: May 2011

Galectin-1 (Gal-1), a carbohydrate-binding protein whose secretion is enhanced by hypoxia, promotes tumor aggressiveness by promoting angiogenesis and T-cell apoptosis. However, the importance of tumor versus host Gal-1 in tumor progression is undefined. Here we offer evidence that implicates tumor Gal-1 and its modulation of T-cell immunity in progression. Comparing Gal-1–deficient mice as hosts for Lewis lung carcinoma cells where Gal-1 levels were preserved or knocked down, we found that tumor Gal-1 was more critical than host Gal-1 in promoting tumor growth and spontaneous metastasis. Enhanced growth and metastasis associated with Gal-1 related to its immunomodulatory function, insofar as the benefits of Gal-1 expression to Lewis lung carcinoma growth were abolished in immunodeficient mice. In contrast, angiogenesis, as assessed by microvessel density count, was similar between tumors with divergent Gal-1 levels when examined at a comparable size. Our findings establish that tumor rather than host Gal-1 is responsible for mediating tumor progression through intratumoral immunomodulation, with broad implications in developing novel targeting strategies for Gal-1 in cancer. Cancer Res; 71(13); 4423–31. ©2011 AACR.
Navitoclax (ABT-263) Accelerates Apoptosis during Drug-Induced Mitotic Arrest by Antagonizing Bcl-xL
Authors: Shi Jue , Zhou Yuan , Huang Hsiao-Chun , Mitchison Timothy J.
Published: May 2011

Combining microtubule-targeting antimitotic drugs with targeted apoptosis potentiators is a promising new chemotherapeutic strategy to treat cancer. In this study, we investigate the cellular mechanism by which navitoclax (previously called ABT-263), a Bcl-2 family inhibitor, potentiates apoptosis triggered by paclitaxel and an inhibitor of kinesin-5 (K5I, also called a KSP inhibitor), across a panel of epithelial cancer lines. By using time-lapse microscopy, we showed that navitoclax has little effect on cell death during interphase, but strongly accelerates apoptosis during mitotic arrest, and greatly increases the fraction of apoptosis-resistant cells that die. By systematically knocking down individual Bcl-2 proteins, we determined that Mcl-1 and Bcl-xL are the primary negative regulators of apoptosis during prolonged mitotic arrest. Mcl-1 levels decrease during mitotic arrest because of an imbalance between synthesis and turnover, and turnover depends in part on the MULE/HUWE1 E3 ligase. The combination of Mcl-1 loss with inhibition of Bcl-xL by navitoclax causes rapid apoptosis in all lines tested. Variation in expression levels of Mcl-1 and Bcl-xL largely determines variation in response to antimitotics alone, and antimitotics combined with navitoclax, across our panel. We concluded that Bcl-xL is a critical target of Bcl-2 family inhibitors for enhancing the lethality of antimitotic drugs in epithelial cancers, and combination treatment with navitoclax and a spindle specific antimitotic, such as a K5I, might be more effective than paclitaxel alone. Cancer Res; 71(13); 4518–26. ©2011 AACR.
Glycolytic Phenotype and AMP Kinase Modify the Pathologic Response of Tumor Xenografts to VEGF Neutralization
Authors: Nardo Giorgia , Favaro Elena , Curtarello Matteo , Moserle Lidia , Zulato Elisabetta , Persano Luca , Rossi Elisabetta , Esposito Giovanni , Crescenzi Marika , Casanovas Oriol , Sattler Ulrike , Mueller-Klieser Wolfgang , Biesalski Barbara , Thews Oliver , Canese Rossella , Iorio Egidio , Zanovello Paola , Amadori Alberto , Indraccolo Stefano
Published: May 2011

VEGF antagonists are now widely used cancer therapeutics, but predictive biomarkers of response or toxicity remain unavailable. In this study, we analyzed the effects of anti-VEGF therapy on tumor metabolism and therapeutic response by using an integrated set of imaging techniques, including bioluminescence metabolic imaging, 18-fluorodeoxyglucose positron emission tomography, and MRI imaging and spectroscopy. Our results revealed that anti-VEGF therapy caused a dramatic depletion of glucose and an exhaustion of ATP levels in tumors, although glucose uptake was maintained. These metabolic changes selectively accompanied the presence of large necrotic areas and partial tumor regression in highly glycolytic tumors. In addition, we found that the central metabolic protein kinase AMP-activated protein kinase (AMPK)—a cellular sensor of ATP levels that supports cell viability in response to energy stress—was activated by anti-VEGF therapy in experimental tumors. AMPK-α2 attenuation increased glucose consumption, tumor cell sensitivity to glucose starvation, and tumor necrosis following anti-VEGF therapy. Taken together, our findings reveal functional links between the Warburg effect and the AMPK pathway with therapeutic responses to VEGF neutralization in tumor xenograft models. Cancer Res; 71(12); 4214–25. ©2011 AACR.
In VivoPersistence, Tumor Localization, and Antitumor Activity of CAR-Engineered T Cells Is Enhanced by Costimulatory Signaling through CD137 (4-1BB)
Authors: Song De-Gang , Ye Qunrui , Carpenito Carmine , Poussin Mathilde , Wang Li-Ping , Ji Chunyan , Figini Mariangela , June Carl H. , Coukos George , Powell Daniel J.
Published: May 2011

Human T cells engineered to express a chimeric antigen receptor (CAR) specific for folate receptor-α (FRα) have shown robust antitumor activity against epithelial cancers in vitro but not in the clinic because of their inability to persist and home to tumor in vivo. In this study, CARs were constructed containing a FRα-specific scFv (MOv19) coupled to the T-cell receptor CD3ζ chain signaling module alone (MOv19-ζ) or in combination with the CD137 (4-1BB) costimulatory motif in tandem (MOv19-BBζ). Primary human T cells transduced to express conventional MOv19-ζ or costimulated MOv19-BBζ CARs secreted various proinflammatory cytokines, and exerted cytotoxic function when cocultured with FRα+ tumor cells in vitro. However, only transfer of human T cells expressing the costimulated MOv19-BBζ CAR mediated tumor regression in immunodeficient mice bearing large, established FRα+ human cancer. MOv19-BBζ CAR T-cell infusion mediated tumor regression in models of metastatic intraperitoneal, subcutaneous, and lung-involved human ovarian cancer. Importantly, tumor response was associated with the selective survival and tumor localization of human T cells in vivo and was only observed in mice receiving costimulated MOv19-BBζ CAR T cells. T-cell persistence and antitumor activity were primarily antigen-driven; however, antigen-independent CD137 signaling by CAR improved T-cell persistence but not antitumor activity in vivo. Our results show that anti-FRα CAR outfitted with CD137 costimulatory signaling in tandem overcome issues of T-cell persistence and tumor localization that limit the conventional FRα T-cell targeting strategy to provide potent antitumor activity in vivo. Cancer Res; 71(13); 4617–27. ©2011 AACR.