bluuebunny/crossref_metadata_2025 huggingface dataset:
Influenza A Virus Expresses High Levels of an Unusual Class of Small Viral Leader RNAs in Infected Cells
Authors: Umbach Jennifer L. , Yen Hui-Ling , Poon Leo L. M. , Cullen Bryan R.
Published: September 2010

Evidence has recently accumulated suggesting that small noncoding RNAs, and particularly microRNAs, have the potential to strongly affect the replication and pathogenic potential of a range of human virus species. Here, we report the use of deep sequencing to comprehensively analyze small viral RNAs (18 to 27 nucleotides [nt]) produced during infection by influenza A virus. Although influenza A virus differs from most other RNA viruses in that it replicates its genome in the nucleus and is therefore exposed to the nuclear microRNA processing factors Drosha and DGCR8, we did not observe any microRNAs encoded by influenza virus genes. However, influenza virus infection did induce the expression of very high levels—over 100,000 copies per cell by 8 h postinfection—of a population of 18- to 27-nt small viral leader RNAs (leRNAs) that originated from the precise 5′ ends of all eight influenza virus genomic RNA (vRNA) segments. Like the vRNAs themselves, our data indicate that the leRNAs also bear a 5′-terminal triphosphate and are therefore not capable of functioning as microRNAs. Instead, the high-level production of leRNAs may imply a role in another aspect of the viral life cycle, such as regulation of the switch from viral mRNA transcription to genomic RNA synthesis.

IMPORTANCE
Influenza A virus is an important human pathogen that has the potential to give rise to serious pandemics. Here, we demonstrate that influenza A virus induces the expression of very high levels of small viral leader RNAs (leRNAs) within hours of infection. These RNAs are unusual in that they bear a 5′ triphosphate and originate from the very 5′ ends of the eight viral genomic RNA (vRNA) segments. Their high expression may imply an important role in the viral life cycle that could potentially serve as a novel target for antiviral drugs.
Actual and projected growth and yields of Populus 'Tristis #1' under intensive culture
Authors: Ek Alan R. , Dawson David H.
Published: September 2010

Yields and related stand characteristics of Populus 'Tristis #1' cuttings based on 4 years of growth under intensive culture (fertilization and irrigation) at square spacings of 0.75, 1, and 2 ft (0.23, 0.30 and 0.61 m) in northern Wisconsin are reported. Stem and branch wood yields were 40 390, 45 132, and 27 567 lb/acre (45 272, 50 586, and 30 899 kg/ha) for these spacings, and current annual increment peaked at age 3 for the 0.75- and 1-ft spacings. Tree growth and competition information from these plots was then used to calibrate a stand growth simulation model to develop yield projections to the 10- to 25-year range for the above plus 4-, 8-, and 12.7-ft (1.22-, 2.44-, and 3.87-m) spacings. Mean annual increment in terms of stem and branch wood dry weight for the projections peaked at about 8–15 years for all six spacings with values in the range of 13 881 – 16 584 lb/acre (15 559 – 18 588 kg/ha), respectively. The maximum mean annual increment was obtained at age 15 with a 4-ft spacing. Results further indicate substantial product-oriented flexibility in the choice of spacings and rotation ages since curves of mean annual increment are both similar and relatively flat in the 10- to 20-year range, except for the two widest spacings. A discussion of stand model projection methodology, reliability, and limitations is presented along with suggestions for more refined projections.
An input–output model of public forest management
Authors: Flick Warren A.
Published: September 2010

Input–output analysis can be used to model the multiresource systems of public forestry agencies. The model provides interdependency coefficients which predict the changes in forest outputs and budget and labor inputs as a function of net production goals. The model also gives shadow prices of forest outputs which are interpreted as the prices implied by public decisions. The model is tested in western Oregon and has useful applications to a variety of planning problems. In each application, the model allows managers to foresee the system-wide consequences of specific management programs, thereby improving the basis for multiple-use decisions.
Biomass and nitrogen distribution in four 13-year-old loblolly pine plantations in the Hilly Coastal Plain of Alabama
Authors: Larsen H. S. , Carter M. C. , Gooding J. W. , Hyink D. M.
Published: September 2010

Four old-field loblolly pine (Pinustaeda L.) plantations of equal age and original spacing on sites of average quality in the Hilly Coastal Plain of Alabama, U.S.A., were sampled. Dry weights and nitrogen contents of all plant biomass components were estimated, including roots, to a 0.61-m depth. Soil nitrogen was estimated to the same depth. Dry weights and nitrogen contents per tree were comparable with those of earlier studies if allowance was made for different season of sampling. Estimated total aboveground mean annual accumulations of biomass and nitrogen 13 years after planting were 8100 kg/ha and 21.4 kg/ha, respectively. Trees comprise 84% of the plant mass and contained 61% of the N associated with plant tissue. However, the N content of the system's plant biomass was only 13% of the total; the remaining 87% was in the soil. Total-tree harvesting, even with stump extraction, would remove only about 7% of the ecosystem's nitrogen. Per hectare estimates obtained in the study differed considerably from some earlier estimates, indicating the need for additional studies in stands of different ages on sites of varying quality.
Vegetative propagation of Piceaglauca by tissue culture
Authors: Campbell Robert A. , Durzan Donald J.
Published: September 2010

By using tissue culture methods, multiple complete white spruce plants were regenerated from individual hypocotyl segments. The plants thrived and grew vigorously after transfer from in vitro culture to soil in pots. There are indications that the method will work with tissue collected from mature trees as well. This provides a potential means for the vegetative propagation of superior genotypes for reforestation.
LOW DENSITY NUCLEAR MATTER IN FERMI ENERGY COLLISIONS
Authors: QIN L. , HAGEL K. , WADA R. , CHEN Z. , HUANG M. , KOWALSKI S. , BOTTOSSO C. , SHLOMO S. , BARBUI M. , BONASERA A. , RODRIGUES M. , NATOWITZ J. B. , RÖPKE G. , FABRIS D. , LUNARDON M. , MORETTO S. , NEBBIA G. , PESENTE S. , VIESTI G. , CINAUSERO M. , PRETE G. , RIZZI V. , KEUTGEN T. , El MASRI Y. , MAJKA Z.
Published: September 2010

Recent heavy ion reaction studies aimed at elucidating the properties of low density matter produced in near Fermi-energies are discussed. At the lowest densities and temperatures large alpha mass fractions are observed. The symmetry free energies derived from isoscaling analyses are far above those obtained in common effective interaction calculations, reflecting cluster formation, primarily of alpha particles, not included in such calculations. Theoretical modeling of these results requires the consideration of cluster formation and medium modifications of cluster properties.
THE PROMINENT ROLE OF THE HEAVIEST FRAGMENT IN MULTIFRAGMENTATION AND PHASE TRANSITION FOR HOT NUCLEI
Authors:   Indra and Aladin Collaborations, BORDERIE B. , BONNET E. , LE NEINDRE N. , PIANTELLI S. , RADUTA Ad. R. , RIVET M. F. , GALICHET E. , GULMINELLI F. , MERCIER D. , TAMAIN B. , BOUGAULT R. , PÂRLOG M. , FRANKLAND J. D. , CHBIHI A. , WIELECZKO J. P. , GUINET D. , LAUTESSE P. , GAGNON-MOISAN F. , ROY R. , VIGILANTE M. , ROSATO E. , DAYRAS R. , ŁUKASIK J.
Published: September 2010

The role played by the heaviest fragment in partitions of multifragmenting hot nuclei is emphasized. Its size/charge distribution (mean value, fluctuations and shape) gives information on properties of fragmenting nuclei and on the associated phase transition.
THE COLLECTIVITY IN CSR 129Xe+129Xe COLLISIONS
Authors: XIE FEI , WU KEJUN , LIU FENG
Published: September 2010

The Heavy Ion Research Facility in Lanzhou (HIRFL) – Cooler Storage Ring (CSR), which can gather few hundreds MeV/nucleon for heavy ion beam energy in the external-target experiments, could make a significant contribution in studying the property of dense matter. By using a Relativistic Transport Model(ART1.0), we study the collectivity of identified hadrons in 129 Xe +129 Xe collisions in CSR energy regions. Our investigation indicates that the anisotropic flow reaches its extremum around 500 MeV/nucleon of beam energy. The system size and EOS dependence on anisotropic flow show that directed flow is very sensitive to the equation of state.
HBT CORRELATION AS A PROBE OF EoS
Authors: LI QINGFENG
Published: September 2010

Based on the UrQMD and the CRAB analyzing program, HBT correlators of nucleons and pions are calculated with beam energies ranging from SIS up to RHIC. It is found that the HBT correlator and the ratio between the HBT radii RO and RS are sensitive to the stiffness of the EoS. A relatively stiff EoS is favored from the RO/RS ratio of pions. For the two-nucleon correlation at SIS beam energies, it is found that both the symmetry potential energy and conditions of constructing clusters at the late stage influence the correlator with the same power.
PROBING THE DENSITY DEPENDENCE OF SYMMETRY ENERGY AT SUBSATURATION DENSITY WITH HICs
Authors: ZHANG YINGXUN , TSANG M. B. , LI ZHUXIA , DANIELEWICZ P. , LYNCH W. G. , LU XIAOHUA
Published: September 2010

The reaction mechanism of the central collisions and peripheral collisions for 112,124 Sn + 112,124 Sn at E/A = 50 MeV is investigated within the framework of the Improved Quantum Molecular Dynamics model. The results show that multifragmentation process is an important mechanism at this energy region, and the influence of the cluster emission on the double n / p ratios and the isospin transport ratio is important. Furthermore, three observables, double n / p ratios, isospin diffusion and the rapidity distribution of the ratio R7 for 112,124 Sn +112,124 Sn at E/A = 50 MeV are analyzed with the Improved Quantum Molecular Dynamics model. The results show that these three observables are sensitive to the density dependence of the symmetry energy. By comparing the calculation results to the data, the consistent constraint on the density dependence of the symmetry energy from these three observables is obtained.
THE AB-INITIO APPROACH TO NUCLEAR MATTER AND ITS EXTREME STATES
Authors: SAMMARRUCA FRANCESCA
Published: September 2010

In this talk, I will review several issues related to the nuclear matter equation of state, with particular emphasis on isospin-asymmetric matter. I will stress the importance of pursuing a microscopic approach towards a better understanding of dense and exotic matter.
SHAPE EVOLUTION OF HIGHLY DEFORMED 75Kr AND PROJECTED SHELL MODEL DESCRIPTION
Authors: YANG YING-CHUN , SUN YANG , TRIVEDI T. , PALIT R. , SHEIKH J. A.
Published: September 2010

A study of recently-measured high spin states of 75 Kr is carried out by using the Projected Shell Model. Calculations are performed up to spin I = 33/2 for the positive parity band and I = 27/2 for the negative parity band. Irregularities found in moment of inertia and in the deduced transition quadrupole moments Q t of the two bands are discussed in terms of the alignment of g 9/2 protons. Our study provides an insight into the shape evolution of the well-deformed nucleus 75 kr .
THE ORIENTATIONAL-AVERAGE EFFECTS OF HEAVY-ION COLLISIONS INDUCED BY DEFORMED NUCLEI AT INTERMEDIATE ENERGY
Authors: CAO X. G. , CAI X. Z. , ZHANG G. Q. , MA Y. G. , CHEN J. G. , FANG D. Q. , GUO W. , LIU G. H. , TIAN W. D. , WANG H. W.
Published: September 2010

The deformed projectiles and targets are expected to play different roles in heavy-ion collisions (HICs) at intermediate energy compared with spherical ones. With an isospin dependent quantum molecular dynamics (IDQMD) model, in despite of averaging all the orientations of axisymmetric deformed 24 Mg + 24 Mg collisions, it is still found that NN collision number, nuclear stopping power (R) and multiplicity of fragments have considerable differences compared with spherical 24 Mg + 24 Mg collisions.
FURTHER EXTENDED THEORIES OF GRAVITATION: PART II
Authors: FATIBENE L. , FERRARIS M. , FRANCAVIGLIA M. , MERCADANTE S.
Published: September 2010

We shall present and analyze two examples of extended theories of gravitation in Palatini formalism with matter that couples to the connection. This will show that the class of Further Extended Theories of Gravitation introduced in [1] does not trivially reduce to f(R) models. It will also produce an example of theory that on-shell endows space–time with a non-trivial Weyl geometry where the connection is not induced by the metric structure (though it is compatible with it in the sense of Ehlers–Pirani–Schild; see [2]).
Soleus muscle in glycosylation-deficient muscular dystrophy is protected from contraction-induced injury
Authors: Gumerson Jessica D. , Kabaeva Zhyldyz T. , Davis Carol S. , Faulkner John A. , Michele Daniel E.
Published: September 2010

The glycosylation of dystroglycan is required for its function as a high-affinity laminin receptor, and loss of dystroglycan glycosylation results in congenital muscular dystrophy. The purpose of this study was to investigate the functional defects in slow- and fast-twitch muscles of glycosylation-deficient Largemyd mice. While a partial alteration in glycosylation of dystroglycan in heterozygous Largemyd/+ mice was not sufficient to alter muscle function, homozygous Largemyd/myd mice demonstrated a marked reduction in specific force in both soleus and extensor digitorum longus (EDL) muscles. Although EDL muscles from Largemyd/myd mice were highly susceptible to lengthening contraction-induced injury, Largemyd/myd soleus muscles surprisingly showed no greater force deficit compared with wild-type soleus muscles even after five lengthening contractions. Despite no increased susceptibility to injury, Largemyd/myd soleus muscles showed loss of dystroglycan glycosylation and laminin binding activity and dystrophic pathology. Interestingly, we show that soleus muscles have a markedly higher sarcolemma expression of β1-containing integrins compared with EDL and gastrocnemius muscles. Therefore, we conclude that β1-containing integrins play an important role as matrix receptors in protecting muscles containing slow-twitch fibers from contraction-induced injury in the absence of dystroglycan function, and that contraction-induced injury appears to be a separable phenotype from the dystrophic pathology of muscular dystrophy.
Imaging of oxygen gradients in monolayer cultured cells using green fluorescent protein
Authors: Takahashi Eiji , Sato Michihiko
Published: September 2010

Gradients of Po2 between capillary blood and mitochondria are the driving force for diffusional O2 delivery in tissues. Hypoxic microenvironments in tissues that result from diffusional O2 gradients are especially relevant in solid tumors because they have been related to a poor prognosis. To address the impact of tissue O2 gradients, we developed a novel technique that permits imaging of intracellular O2 levels in cultured cells at a subcellular spatial resolution. This was done, with the sensitivity to O2 ≤3%, by the O2-dependent red shift of green fluorescent protein (AcGFP1) fluorescence. Measurements were carried out in a confluent monolayer of Hep3B cells expressing AcGFP1 in the cytoplasm. To establish a two-dimensional O2 diffusion model, a thin quartz glass slip was placed onto the monolayer cells to prevent O2 diffusion from the top surface of the cell layer. The magnitude of the red shift progressively increased as the distance from the gas coverslip interface increased. It reached an anoxic level in cells located at ∼220 μm and ∼690 μm from the gas coverslip boundary at 1% and 3% gas phase O2, respectively. Thus the average O2 gradient was 0.03 mmHg/μm in the present tissue model. Abolition of mitochondrial respiration significantly dampened the gradients. Furthermore, intracellular gradients of the red shift in mitochondria-targeted AcGFP1 in single Hep3B cells suggest that the origin of tissue O2 gradients is intracellular. Findings in the present two-dimensional O2 diffusion model support the crucial role of tissue O2 diffusion in defining the O2 microenvironment in individual cells.
Genetic downregulation of AMPK-α isoforms uncovers the mechanism by which metformin decreases FA uptake and oxidation in skeletal muscle cells
Authors: Bogachus Lindsey D. , Turcotte Lorraine P.
Published: September 2010

Metformin is known to improve insulin sensitivity in part via a rise in AMP-activated protein kinase (AMPK) activity and alterations in muscle metabolism. However, a full understanding of how metformin alters AMPK-α1 vs. AMPK-α2 activation remains unknown. To study this question, L6 skeletal muscle cells were treated with or without RNAi oligonucleotide sequences to downregulate AMPK-α1 or AMPK-α2 protein expression and incubated with or without 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR) or metformin and/or insulin. In contrast to AICAR, which preferentially activated AMPK-α2, metformin preferentially activated AMPK-α1 in a dose- and time-dependent manner. Metformin increased ( P < 0.05) glucose uptake and plasma membrane (PM) Glut4 in a dose- and time-dependent manner. Metformin significantly reduced palmitate uptake ( P < 0.05) and oxidation ( P < 0.05), and this was accompanied by a similar decrease ( P < 0.05) in PM CD36 content but with no change in acetyl-CoA carboxylase (ACC) phosphorylation ( P > 0.05). AICAR and metformin similarly increased ( P < 0.05) nuclear silent mating-type information regulator 2 homolog 1 (SIRT1) activity. Downregulation of AMPK-α1 completely prevented the metformin-induced reduction in palmitate uptake and oxidation but only partially reduced the metformin-induced increase in glucose uptake. Downregulation of AMPK-α2 had no effect on metformin-induced glucose uptake, palmitate uptake, and oxidation. The increase in SIRT1 activity induced by metformin was not affected by downregulation of either AMPK-α1 or AMPK-α2. Our data indicate that, in muscle cells, the inhibitory effects of metformin on fatty acid metabolism occur via preferential phosphorylation of AMPK-α1, and the data indicate that cross talk between AMPK and SIRT1 does not favor either AMPK isozyme.
Differential gene expressions in atrial and ventricular myocytes: insights into the road of applying embryonic stem cell-derived cardiomyocytes for future therapies
Authors: Ng Sze Ying , Wong Chun Kit , Tsang Suk Ying
Published: September 2010

Myocardial infarction has been the leading cause of morbidity and mortality in developed countries over the past few decades. The transplantation of cardiomyocytes offers a potential method of treatment. However, cardiomyocytes are in high demand and their supply is extremely limited. Embryonic stem cells (ESCs), which have been isolated from the inner cell mass of blastocysts, can self-renew and are pluripotent, meaning they have the ability to develop into any type of cell, including cardiomyocytes. This suggests that ESCs could be a good source of genuine cardiomyocytes for future therapeutic purposes. However, problems with the yield and purity of ESC-derived cardiomyocytes, among other hurdles for the therapeutic application of ESC-derived cardiomyocytes (e.g., potential immunorejection and tumor formation problems), need to be overcome before these cells can be used effectively for cell replacement therapy. ESC-derived cardiomyocytes consist of nodal, atrial, and ventricular cardiomyocytes. Specifically, for treatment of myocardial infarction, transplantation of a sufficient quantity of ventricular cardiomyocytes, rather than nodal or atrial cardiomyocytes, is preferred. Hence, it is important to find ways of increasing the yield and purity of specific types of cardiomyocytes. Atrial and ventricular cardiomyocytes have differential expression of genes (transcription factors, structural proteins, ion channels, etc.) and are functionally distinct. This paper presents a thorough review of differential gene expression in atrial and ventricular myocytes, their expression throughout development, and their regulation. An understanding of the molecular and functional differences between atrial and ventricular myocytes allows discussion of potential strategies for preferentially directing ESCs to differentiate into chamber-specific cells, or for fine tuning the ESC-derived cardiomyocytes into specific electrical and contractile phenotypes resembling chamber-specific cells.
Dehydration followed by sham rehydration contributes to reduced neuronal activation in vasopressinergic supraoptic neurons after water deprivation
Authors: Knight W. David , Ji Lisa L. , Little Joel T. , Cunningham J. Thomas
Published: September 2010

This experiment tested the role of oropharyngeal and gastric afferents on hypothalamic activation in dehydrated rats instrumented with gastric fistulas and allowed to drink water or isotonic saline compared with euhydrated controls (CON). Rats were water-deprived for 48 h (48 WD) or 46 h WD with 2 h rehydration with water (46+W) or isotonic saline (46+S). 46+W and 46+S rats were given water with fistulas open (46+WO/46+SO, sham) or closed (46+WC/46+SC). Compared with CON, water deprivation increased and water rehydration decreased plasma osmolality, while sham rehydration had no effect. Water deprivation increased c-Fos staining in the lamina terminalis. However, none of the sham or rehydration treatments normalized c-Fos staining in the lamina terminalis. Analysis of AVP and c-Fos-positive neurons in the supraoptic nucleus (SON) revealed reduced colocalization in 46+WO and 46+SC rats compared with 48 WD and 46+SO rats. However, 46+WO and 46+SC rats had higher c-Fos staining in the SON than 46+WC or CON rats. Examination of c-Fos in the perinuclear zone (PNZ) revealed that sham and rehydrated rats had increased c-Fos staining to CON, while 48 WD and 46+SO rats had little or no c-Fos staining in this region. Thus, preabsorptive reflexes contribute to the regulation of AVP neurons in a manner independent of c-Fos expression in the lamina terminalis. Further, this reflex pathway may include inhibitory interneurons in the PNZ region surrounding the SON.
CCAAT/enhancer binding protein-δ expression is increased in fast skeletal muscle by food deprivation and regulates myostatin transcription in vitro
Authors: Allen David L. , Cleary Allison S. , Hanson Andrea M. , Lindsay Sarah F. , Reed Jason M.
Published: September 2010

We recently demonstrated that mRNA levels of three members of the CCAAT/enhancer binding factor (C/EBP) family of transcription factors are increased in skeletal muscle following 12 days of spaceflight. In the present study, we further explored the expression of C/EBP-δ in atrophying fast skeletal muscle by examining its expression in muscle from food-deprived (FD) mice, and investigated its role in regulating the expression of the secreted antigrowth factor myostatin. C/EBP-δ mRNA and protein levels were significantly increased by 2 days of food deprivation in the tibialis anterior (TA) muscle, and expression of both myostatin and C/EBP-δ mRNA during food deprivation was attenuated by injection with the glucocorticoid inhibitor RU486. The increase in myostatin mRNA levels with food deprivation appears to be at least partially transcriptionally driven, since levels of myostatin pre-mRNA were significantly increased in the TA muscle. C/EBP-δ mRNA levels and promoter activity were significantly increased by transfection of C2C12 myotubes with a glucocorticoid receptor construct and 24 h of treatment with the synthetic glucocorticoid dexamethasone. Furthermore, activity of the C/EBP-δ promoter was significantly increased with as little as 1 h of dexamethasone treatment, while activity of the mouse myostatin promoter was only significantly increased with longer treatment periods of 24 h or more. Activity of the myostatin promoter-reporter construct was significantly increased in C2C12 myotubes by cotransfection with expression constructs for C/EBP-α, -β, and -δ, with C/EBP-δ having the greatest effect. The myostatin promoter contains two potential C/EBP binding sequences, a CCAAT box, and a C/EBP binding element (CBE). Mutation of the CCAAT box attenuated basal myostatin promoter activity but potentiated C/EBP-δ-activated myostatin promoter activity in C2C12 myotubes in vitro, while mutation of the CBE abolished glucocorticoid receptor and C/EBP-δ responsiveness. The present results support a model in which glucocorticoid-induced increases in C/EBP-δ expression may contribute to myostatin transcription during atrophic states.
Top-down control analysis of the cadmium effects on molluscan mitochondria and the mechanisms of cadmium-induced mitochondrial dysfunction
Authors: Kurochkin Ilya O. , Etzkorn Markus , Buchwalter David , Leamy Larry , Sokolova Inna M.
Published: September 2010

Cadmium (Cd) is a toxic metal and an important environmental pollutant that can strongly affect mitochondrial function and bioenergetics in animals. We investigated the mechanisms of Cd action on mitochondrial function of a marine mollusk (the eastern oyster Crassostrea virginica ) by performing a top-down control analysis of the three major mitochondrial subsystems (substrate oxidation, proton leak, and phosphorylation). Our results showed that the substrate oxidation and proton leak subsystems are the main targets for Cd toxicity in oyster mitochondria. Exposure to 12.5 μM Cd strongly inhibited the substrate oxidation subsystem and stimulated the proton conductance across the inner mitochondrial membrane. Proton conductance was also elevated and substrate oxidation inhibited by Cd in the presence of a mitochondrially targeted antioxidant, MitoVitE, indicating that Cd effects on these subsystems were to a large extent ROS independent. Cd did not affect the kinetics of the phosphorylation system, indicating that it has negligible effects on F1, FOATP synthase and/or the adenine nucleotide transporter in oyster mitochondria. Cd exposure altered the patterns of control over mitochondrial respiration, increasing the degree of control conferred by the substrate oxidation subsystem, especially in resting (state 4) mitochondria. Taken together, these data suggest that Cd-induced decrease of mitochondrial efficiency and ATP production are predominantly driven by the high sensitivity of substrate oxidation and proton leak subsystems to this metal.
Leupeptin-based inhibitors do not improve the mdx phenotype
Authors: Selsby Joshua , Pendrak Klara , Zadel Monica , Tian Zuozhen , Pham Jennifer , Carver Ted , Acosta Pedro , Barton Elisabeth , Sweeney H. Lee
Published: September 2010

Calpain activation has been implicated in the disease pathology of Duchenne muscular dystrophy. Inhibition of calpain has been proposed as a promising therapeutic target, which could lessen the protein degradation and prevent progressive fibrosis. At the same time, there are conflicting reports as to whether elevation of calpastatin, an endogenous calpain inhibitor, alters pathology. We compared the effects of pharmacological calpain inhibition in the mdx mouse using leupeptin and a proprietary compound (C101) that linked the inhibitory portion of leupeptin to carnitine (to increase uptake into muscle). Administration of C101 for 4 wk did not improve muscle histology, function, or serum creatine kinase levels in mdx mice. Mdx mice injected daily with leupeptin (36 mg/kg) for 6 mo also failed to show improved muscle function, histology, or creatine kinase levels. Biochemical analysis revealed that leupeptin administration caused an increase in m-calpain autolysis and proteasome activity, yet calpastatin levels were similar between treated and untreated mdx mice. These data demonstrate that pharmacological inhibition of calpain is not a promising intervention for the treatment of Duchenne muscular dystrophy due to the ability of skeletal muscle to counter calpain inhibitors by increasing multiple degradative pathways.
Eicosapentaenoic acid restores diabetic tubular injury through regulating oxidative stress and mitochondrial apoptosis
Authors: Taneda Sekiko , Honda Kazuho , Tomidokoro Kimiko , Uto Kenta , Nitta Kosaku , Oda Hideaki
Published: September 2010

The present study was designed to elucidate a possible mechanism of hyperglycemia-induced tubular injury and to examine a therapeutic potential of dietary eicosapentaenoic acid (EPA) for the prevention of diabetic kidney disease. Utilizing streptozotocin-induced diabetic mice, the extents of albuminuria and histological injuries were monitored at 2 wk after diabetic induction. Reactive oxygen species (ROS) production, apoptosis, and hypoxia in the kidney were evaluated by immunohistochemistry and Western blotting. An in vitro study was performed using rat proximal tubular cells (NRK-52E) to confirm the protective effect of EPA for methylglyoxal (MG)-induced ROS generation and staurosporine (STS)-induced mitochondrial apoptosis. The extents of albuminuria and histological tubular injuries were significantly lower in EPA-treated diabetic mice compared with untreated diabetic mice. The levels of lipid peroxidation product (4-hydroxy-2-nonenal), oxidative DNA damage (8-hydoxy-deoxyguanosine), and mitochondrial apoptosis (TUNEL, caspase-9, cleaved caspase-3, and cytochrome c release) in the tubular cells were also significantly lower in EPA-treated diabetic mice. Furthermore, hypoxia-inducible factor (HIF)-1α expression was significantly upregulated in the kidney tissues from EPA-treated mice compared with untreated diabetic mice. MG-induced ROS overproduction and STS-induced mitochondrial apoptosis in NRK-52E cells were significantly reduced by EPA treatment in vitro. These results indicated that the ROS generation and mitochondrial apoptosis were involved in hyperglycemia-induced tubular injury and EPA had a beneficial effect by suppressing ROS generation and mitochondrial apoptosis partly through augmentation of an HIF-1α response in diabetic kidney disease.
Direct comparison of in vivo Achilles tendon moment arms obtained from ultrasound and MR scans
Authors: Fath Florian , Blazevich Anthony J. , Waugh Charlie M. , Miller Stuart C. , Korff Thomas
Published: September 2010

Accurate and reliable estimation of muscle moment arms is a prerequisite for the development of musculoskeletal models. Numerous techniques are available to estimate the Achilles tendon moment arm in vivo. The purposes of this study were 1) to compare in vivo Achilles tendon moment arms obtained using the center of rotation (COR) and tendon excursion (TE) methods and 2) to assess the reliability of each method. For the COR method, magnetic resonance (MR) images from nine participants were obtained at ankle angles of −15°, 0°, and +15° and analyzed using Reuleaux' method. For the TE method, the movement of the gastrocnemius medialis-Achilles tendon junction was recorded using ultrasonography as the ankle was passively rotated through its range of motion. The Achilles tendon moment arm was obtained by differentiation of tendon displacement with respect to ankle angular excursion using seven different differentiation techniques. Moment arms obtained using the COR method were significantly greater than those obtained using the TE method ( P < 0.01), but results from both methods were well correlated. The coefficient of determination between moment arms derived from the COR and TE methods was highest when tendon displacement was linearly differentiated over a ±10° interval ( R2 = 0.94). The between-measurement coefficient of variation was 3.9% for the COR method and 4.5–9.7% for the TE method, depending on the differentiation technique. The high reliabilities and strong relationship between methods demonstrate that both methods are robust against their limitations. The large absolute between-method differences (∼25–30%) in moment arms have significant implications for their use in musculoskeletal models.
Bowman-Birk inhibitor attenuates dystrophic pathology in mdx mice
Authors: Morris C. A. , Selsby J. T. , Morris L. D. , Pendrak K. , Sweeney H. L.
Published: September 2010

Bowman-Birk inhibitor concentrate (BBIC), a serine protease inhibitor, has been shown to diminish disuse atrophy of skeletal muscle. Duchenne muscular dystrophy (DMD) results from a loss of dystrophin protein and involves an ongoing inflammatory response, with matrix remodeling and activation of transforming growth factor (TGF)-β1 leading to tissue fibrosis. Inflammatory-mediated increases in extracellular protease activity may drive much of this pathological tissue remodeling. Hence, we evaluated the ability of BBIC, an extracellular serine protease inhibitor, to impact pathology in the mouse model of DMD (mdx mouse). Mdx mice fed 1% BBIC in their diet had increased skeletal muscle mass and tetanic force and improved muscle integrity (less Evans blue dye uptake). Importantly, mdx mice treated with BBIC were less susceptible to contraction-induced injury. Changes consistent with decreased degeneration/regeneration, as well as reduced TGF-β1 and fibrosis, were observed in the BBIC-treated mdx mice. While Akt signaling was unchanged, myostatin activitation and Smad signaling were reduced. Given that BBIC treatment increases mass and strength, while decreasing fibrosis in skeletal muscles of the mdx mouse, it should be evaluated as a possible therapeutic to slow the progression of disease in human DMD patients.
Spatially Distributed Encoding of Covert Attentional Shifts in Human Thalamus
Authors: Hulme Oliver J. , Whiteley Louise , Shipp Stewart
Published: September 2010

Spatial attention modulates signal processing within visual nuclei of the thalamus—but do other nuclei govern the locus of attention in top-down mode? We examined functional MRI (fMRI) data from three subjects performing a task requiring covert attention to 1 of 16 positions in a circular array. Target position was cued after stimulus offset, requiring subjects to perform target detection from iconic visual memory. We found positionally specific responses at multiple thalamic sites, with individual voxels activating at more than one direction of attentional shift. Voxel clusters at anatomically equivalent sites across subjects revealed a broad range of directional tuning at each site, with little sign of contralateral bias. By reference to a thalamic atlas, we identified the nuclear correspondence of the four most reliably activated sites across subjects: mediodorsal/central-intralaminar (oculomotor thalamus), caudal intralaminar/parafascicular, suprageniculate/limitans, and medial pulvinar/lateral posterior. Hence, the cortical network generating a top-down control signal for relocating attention acts in concert with a spatially selective thalamic apparatus—the set of active nuclei mirroring the thalamic territory of cortical “eye-field” areas, thus supporting theories which propose the visuomotor origins of covert attentional selection.
Contribution of the Premotor Cortex to Consolidation of Motor Sequence Learning in Humans During Sleep
Authors: Nitsche Michael A. , Jakoubkova Michaela , Thirugnanasambandam Nivethida , Schmalfuss Leonie , Hullemann Sandra , Sonka Karel , Paulus Walter , Trenkwalder Claudia , Happe Svenja
Published: September 2010

Motor learning and memory consolidation require the contribution of different cortices. For motor sequence learning, the primary motor cortex is involved primarily in its acquisition. Premotor areas might be important for consolidation. In accordance, modulation of cortical excitability via transcranial DC stimulation (tDCS) during learning affects performance when applied to the primary motor cortex, but not premotor cortex. We aimed to explore whether premotor tDCS influences task performance during motor memory consolidation. The impact of excitability-enhancing, -diminishing, or placebo premotor tDCS during rapid eye movement (REM) sleep on recall in the serial reaction time task (SRTT) was explored in healthy humans. The motor task was learned in the evening. Recall was performed immediately after tDCS or the following morning. In two separate control experiments, excitability-enhancing premotor tDCS was performed 4 h after task learning during daytime or immediately before conduction of a simple reaction time task. Excitability-enhancing tDCS performed during REM sleep increased recall of the learned movement sequences, when tested immediately after stimulation. REM density was enhanced by excitability-increasing tDCS and reduced by inhibitory tDCS, but did not correlate with task performance. In the control experiments, tDCS did not improve performance. We conclude that the premotor cortex is involved in motor memory consolidation during REM sleep.
Neural Representation During Visually Guided Reaching in Macaque Posterior Parietal Cortex
Authors: Heider Barbara , Karnik Anushree , Ramalingam Nirmala , Siegel Ralph M.
Published: September 2010

Visually guided hand movements in primates require an interconnected network of various cortical areas. Single unit firing rate from area 7a and dorsal prelunate (DP) neurons of macaque posterior parietal cortex (PPC) was recorded during reaching movements to targets at variable locations and under different eye position conditions. In the eye position–varied task, the reach target was always foveated; thus eye position varied with reach target location. In the retinal-varied task, the monkey reached to targets at variable retinotopic locations while eye position was kept constant in the center. Spatial tuning was examined with respect to temporal (task epoch) and contextual (task condition) aspects, and response fields were compared. The analysis showed distinct tuning types. The majority of neurons changed their gain field tuning and retinotopic tuning between different phases of the task. Between the onset of visual stimulation and the preparatory phase (before the go signal), about one half the neurons altered their firing rate significantly. Spatial response fields during preparation and initiation epochs were strongly influenced by the task condition (eye position varied vs. retinal varied), supporting a strong role of eye position during visually guided reaching. DP neurons, classically considered visual, showed reach related modulation similar to 7a neurons. This study shows that both area 7a and DP are modulated during reaching behavior in primates. The various tuning types in both areas suggest distinct populations recruiting different circuits during visually guided reaching.
Laparoscopic Splenectomy for Hairy Cell Leukemia in Pregnancy
Authors: Adeniji Beni Adegoke , Fallas Moses , Incerpi Marc , Hamburg Solomon , Katz Robert , Ogunyemi Dotun
Published: September 2010

Objective. We present a successful case of laparoscopic splenectomy for a massively enlarged spleen at 25 weeks of gestation for hairy cell leukemia in pregnancy in a woman with initial hemoglobin of 4.3 gm/dl and platelet count of 18,000/mm3.Study Design. Case report.Results. This report provides an approach to management that may be applicable in those cases where thrombocytopenia or other clinical imperatives preclude delaying treatment till after pregnancy.Conclusion. Hairy cell leukemia is a clonal B-Cell malignancy, for which there is very limited experience worldwide for its management when it occurs during pregnancy. Laparoscopic splenectomy should be considered as a therapeutic option, even with a significantly enlarged spleen, in order to avoid the risks of fetal exposure to chemotherapeutic agents. Unique considerations relating to pregnancy are highlighted.
Multiplicity of Solutions for Gradient Systems Using Landesman‐Lazer Conditions
Authors: da Silva Edcarlos D.
Published: September 2010

We establish existence and multiplicity of solutions for an
elliptic system which presents resonance at infinity of Landesman‐Lazer type. In order to describe the resonance, we use an eigenvalue problem with indefinite weights. In all results, we use Variational Methods, Morse Theory and Critical Groups.
The Effects of Coupling Agents on the Properties of Polyimide/Nano‐Al2O3 Three‐Layer Hybrid Films
Authors: Liu Lizhu , Weng Ling , Song Yuxia , Gao Lin , Lei Qingquan
Published: September 2010

PI/nano‐Al2O3 hybrid films were prepared by ultrasonic‐mechanical method. Before addition, nano‐Al2O3 particles were firstly modified with different coupling agents. The micromorphology, thermal stability, mechanical properties, and electric breakdown strength of hybrid films were characterized and investigated. Results indicated that nano‐Al2O3 particles were homogeneously dispersed in the PI matrix by the addition of coupling agents. The thermal stability and mechanical properties of PI/nano‐Al2O3 composite films with KH550 were the best. The tensile strength and elongation at break of PI composite film were 119.1 MPa and 19.1%, which were 14.2% and 78.5% higher than unmodified PI composite film, respectively.
Classification of Triangle‐Free 223 Configurations
Authors: Al-Azemi Abdullah , Betten Anton
Published: September 2010

The 157, 211 triangle‐free symmetric 223 configurations are classified and some of their
properties are examined. We conclude that each such configuration has a blocking set. Further
properties like transitivity on lines, self‐duality, and self‐polarity are discussed.
Management of Pain in Children with Burns
Authors: Gandhi M. , Thomson C. , Lord D. , Enoch S.
Published: September 2010

Burn injuries are common in children under 10 years of age. Thermal injury is the most common mechanism of injury and scalds account for >60% of such injuries. All children with burns will experience pain, regardless of the cause, size, or burn depth. Undertreated pain can result in noncompliance with treatment and, consequently, prolonged healing. It is acknowledged that the monitoring and reporting of pain in children with burns has generally been poor. Due to the adverse physiological and emotional effects secondary to pain, adequate pain control is an integral and requisite component in the management of children with burns. A multidisciplinary approach is frequently necessary to achieve a robust pain relief. Key to successful treatment is the continuous and accurate assessment of pain and the response to therapy. This clinical review article discusses the essential aspects of the pathophysiology of burns in children provides an overview of pain assessment, the salient principles in managing pain, and the essential pharmacodynamics of commonly used drugs in children with burn injuries. Both pharmacological and nonpharmacological treatment options are discussed, although a detailed review of the latter is beyond the scope and remit of this article.
Acoustic Echo Cancellation Embedded in Smart Transcoding Algorithm between 3GPP AMR‐NB Modes
Authors: Thepie Fapi Emmanuel Rossignol , Pastor Dominique , Beaugeant Christophe , Taddei Hervé
Published: September 2010

Acoustic Echo Cancellation (AEC) is a necessary feature for mobile devices when the acoustic coupling between the microphone and the loudspeaker affects the communication quality and intelligibility. When implemented inside the network, decoding is required to access the corrupted signal. The AEC performance is strongly degraded by nonlinearity introduced by speech codecs. The Echo Return Loss Enhancement (ERLE) can be less than 10 dB for low bit rate speech codecs. We propose in this paper a coded domain AEC integrated in a smart transcoding strategy which directly modifies the Code Excited Linear Prediction (CELP) parameters. The proposed system addresses simultaneously problems due to network interoperability and network voice quality enhancement. The ERLE performance of this new approach during transcoding between Adaptive Multirate‐NarrowBand (AMR‐NB) modes is above 45 dB as required in Global System for Mobile Communications (GSM) specifications.
Global Modeling of the Oceanic Source of Organic Aerosols
Authors: Myriokefalitakis Stelios , Vignati Elisabetta , Tsigaridis Kostas , Papadimas Christos , Sciare Jean , Mihalopoulos Nikolaos , Facchini Maria Cristina , Rinaldi Matteo , Dentener Frank J. , Ceburnis Darius , Hatzianastasiou Nikos , O′Dowd Colin D. , van Weele Michiel , Kanakidou Maria
Published: September 2010

The global marine organic aerosol budget is investigated by a 3‐dimensional chemistry‐transport model considering recently proposed parameterisations of the primary marine organic aerosol (POA) and secondary organic aerosol (SOA) formation from the oxidation of marine volatile organic compounds. MODIS and SeaWiFS satellite data of Chlorophyll‐a and ECMWF solar incoming radiation, wind speed, and temperature are driving the oceanic emissions in the model. Based on the adopted parameterisations, the SOA and the submicron POA marine sources are evaluated at about 5 Tg yr−1 (~1.5 Tg C yr−1) and 7 to 8 Tg yr−1 (~4 Tg C yr−1), respectively. The computed marine SOA originates from the dimethylsulfide oxidation (~78%), the potentially formed dialkyl amine salts (~21%), and marine hydrocarbon oxidation (~0.1%). Comparison of calculations with observations indicates an additional marine source of soluble organic carbon that could be partially encountered by marine POA chemical ageing.
Oblique Du-Fort Frankel Beam Propagation Method
Authors: Chan Ken , Sewell Philip , Vukovic Ana , Benson Trevor
Published: September 2010

The oblique BPM based on the Du-Fort Frankel method is presented. The paper demonstrates the accuracy and the computational improvements of the scheme compared to the oblique BPM based on Crank-Nicholson (CN) scheme.
Simple Synthesis and Luminescence Characteristics of PVP-Capped GeO2Nanoparticles
Authors: Wu Wei , Zou Xu , Li Quanjun , Liu Bingbing , Liu Bo , Liu Ran , Liu Dedi , Li Zepeng , Cui Wen , Liu Zhaodong , Li Dongmei , Cui Tian , Zou Guangtian
Published: September 2010

Polyvinylpyrrolidone (PVP)-capped rutile GeO2nanoparticles were synthesized through a facile hydrothermal process. The obtained nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), and photoluminescence spectroscopy (PL). The capped GeO2nanoparticles showed significantly enhanced luminescence properties compared with those of the uncapped ones. We attributed this result to the effect of reducing surface defects and enhancing the possibility of electron-hole recombination of the GeO2nanoparticles by the PVP molecules. PVP-capped GeO2nanoparticles have potential application in optical and electronic fields.
Body Composition as Determinant of Thrombin Generation in Plasma
Authors: Beijers Hanneke J.B.H. , Ferreira Isabel , Spronk Henri M.H. , Bravenboer Bert , Dekker Jacqueline M. , Nijpels Giel , ten Cate Hugo , Stehouwer Coen D.A.
Published: September 2010

Objective—

The association between obesity and cardiovascular disease and venous thromboembolism might, at least partially, be explained by a hypercoagulable state. The extent to which body fat mass and its distribution contribute to a hypercoagulable state is unknown. In this study, we investigated the association between body composition and thrombin generation and evaluated the potential mediating role of low-grade inflammation.

Methods and Results—

We studied 586 individuals from the Hoorn Study (mean age, 69.7±6.5 years, 298 women) in whom body composition was assessed by whole body dual-energy absorptiometry. Thrombin generation was measured using the Calibrated Automated Thrombogram. Multiple regression analyses showed a positive association between total body fat and thrombin generation in women but not in men. In addition, detailed analyses of regional body composition showed that central but not peripheral fat mass was associated with greater thrombin generation and that there was a trend toward an inverse association with peripheral lean mass. The reported positive associations were partially attenuated by low-grade inflammation, however.

Conclusion—

Body fat mass, in particular a central pattern of fat distribution, is associated with higher levels of thrombin generation in elderly women but not in men. This association may partially be explained by adiposity-related low-grade inflammation, but this hypothesis needs to be further investigated in mechanistic/prospective studies.