bluuebunny/crossref_metadata_2025 huggingface dataset:
Involvement of Glutamate Transporter-1 in Neuroprotection against Global Brain Ischemia-Reperfusion Injury Induced by Postconditioning in Rats
Authors: Zhang Weiqiao , Miao Yifeng , Zhou Sanquan , Wang Baofeng , Luo Qizhong , Qiu Yongming
Published: November 2010

Ischemic postconditioning refers to several transient reperfusion and ischemia cycles after an ischemic event and before a long duration of reperfusion. The procedure produces neuroprotective effects. The mechanisms underlying these neuroprotective effects are poorly understood. In this study, we found that most neurons in the CA1 region died after 10 minutes of ischemia and is followed by 72 hours of reperfusion. However, brain ischemic postconditioning (six cycles of 10 s/10 s reperfusion/re-occlusion) signiﬁcantly reduced neuronal death. Signiﬁcant up-regulation of Glutamate transporter-1 was found after 3, 6, 24, 72 hours of reperfusion. The present study showed that ischemic postconditioning decreases cell death and that upregulation of GLT-1 expression may play an important role on this effect.
Hepatitis C Virus: Propagation, Quantification, and Storage
Authors: Yi MinKyung
Published: November 2010

Hepatitis C virus (HCV) is a leading cause of chronic liver diseases, including chronic hepatitis, cirrhosis, and hepatocellular carcinoma. HCV is well known for its restricted tropism and it does not replicate well in animal species other than humans and chimpanzees. Since classical in vitro propagation of natural HCV isolates is not possible, a protocol for the rescue of infectious virus from cDNA clones (genotype 1a pH77S and genotype 2a pJFH‐1) transfected as RNA into permissive cells is described here. Because these two molecular clones behave differently in their ability to propagate and produce infectious virus, different methods for propagation of these two viral strains are described. Methods for infectious virus titration, which can be accomplished by counting foci of infected cells following immunostaining for viral antigen expression in cells infected with serial dilutions of a virus harvest (focus forming unit, or FFU, assay), are also provided. Curr. Protoc. Microbiol. 19:15D.1.1‐15D.1.11. © 2010 by John Wiley & Sons, Inc.
A High‐Throughput Approach for Studying Virus Replication in Yeast
Authors: Pogany Judit , Panavas Tadas , Serviene Elena , Nawaz‐ul‐Rehman Muhammad Shah , D. Nagy Peter
Published: November 2010

Viruses are intracellular pathogens that are dependent on viral and host factors for multiplication. Model hosts, such as yeast, can be very valuable in identifying host factors involved in viral replication. Yeast is also useful for studies on functional interactions of host factors with viral proteins and/or virus nucleic acids. The advantages of using yeast include the availability of a single gene–deletion library and the essential gene library (yTHC); the controllable small‐ or large‐scale expression of viral proteins and nucleic acids; and the rapid growth of yeast strains. Procedures that facilitate high‐throughput analysis of host factors and plant and animal RNA virus replication in yeast, with a plant virus (tombusvirus; TBSV) and an animal virus (nodavirus; FHV) as examples, are described. Curr. Protoc. Microbiol. 19:16J.1.1‐16J.1.15. © 2010 by John Wiley & Sons, Inc.
Intelligent Wood Assemblies: Incorporating Found Geometry and Natural Material Complexity
Authors: Enns Jonathan
Published: November 2010

The onset of digital technology has seen the embracing on nonstandard design techniques that use standardised materials, typified by the use of milled plywood. Jonathan Enns describes a project that he has developed at Princeton seeking to harness the irregular and materially complex nature of the innate geometry in timber in such as way as to directly characterise the final design. Copyright © 2010 John Wiley & Sons, Ltd.
High‐temperature oxidation of aniline to highly ordered polyaniline–sulfate salt with a nanofiber morphology and its use as electrode materials in symmetric supercapacitors
Authors: Palaniappan Srinivasan , Sydulu Singu Bal , Prasanna Taneeru Lakshmi , Srinivas Pabba
Published: November 2010

In this study, for the first time, aniline was oxidized by ammonium persulfate (APS) at higher temperatures without any protic acid, and APS acted as an oxidizing agent and a protonating agent. During the oxidation of aniline by APS, sulfuric acid formation occurred, and the sulfuric acid was incorporated into polyaniline (PANI) as a dopant. PANI–sulfate samples were characterized by IR spectroscopy, X‐ray diffraction, and scanning electron microscopy techniques. In this methodology, a highly ordered PANI–sulfate salt (H2SO4) with a nanofiber morphology was synthesized. Interestingly, a PANI base was also obtained with a highly ordered structure with an agglomerated netlike nanofiber morphology. PANI–H2SO4 was used as an electrode material in a symmetric supercapacitor cell. Electrochemical characterization, including cyclic voltammetry (CV), charge–discharge (CD), and impedance analysis, was carried out on the supercapacitor cells. In this study, the maximum specific capacitance obtained was found to be 273 F/g at 1 mV/s. Scan rate from cyclic voltammetry and 103 F/g at 1 mA discharge current from CD measurement. Impedance measurement was carried out at 0.6 V, and it showed a specific capacitance of 73.2 F/g. The value of the specific capacitance and energy and power densities for the PANI–H2SO4 system were calculated from CD studies at a 5‐mA discharge rate and were found to be 43 F/g, 9.3 W h/kg, and 500 W/kg, respectively, with 98–100% coulombic efficiency. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Thermal and mechanical properties of anhydride‐cured epoxy resins with different contents of biobased epoxidized soybean oil
Authors: Altuna F. I. , Espósito L. H. , Ruseckaite R. A. , Stefani P. M.
Published: November 2010

Thermosetting resins were synthesized by the partial replacement of the synthetic epoxy prepolymer based on diglycidyl ether of bisphenol A (DGEBA) with increasing amounts of epoxidized soybean oil (ESO) with methyltetrahydrophthalic anhydride as a crosslinking agent and 1‐methyl imidazole as an initiator. Calorimetric studies showed a drop in the reaction heat with ESO content; this was associated with the lower reactivity of oxirane rings in ESO due to steric constrains. The effects of the replacement of increasing amounts of synthetic DGEBA with ESO on the network properties, such as the storage modulus (E′) in the glassy and rubbery regions, glass‐transition temperature (Tg), and impact and compressive properties were examined. All formulations were transparent, although phase‐separated morphologies were evidenced by scanning electron microscopy observations. The intensity of the transmitted light passed to a minimum at a short reaction time associated with the cloud point and then increased continuously until the refractive index of the dispersed phase approximated that of the continuous phase at complete conversion. The combination of DGEBA with 40 wt % ESO resulted in a resin with an optimum set of properties; E′ in the glassy state was 93% of that of the neat DGEBA resin, Tg decreased only about 11°C, and the impact strength increased about 38% without a loss of transparency. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of annealing on the crystallization and properties of electrospun polylatic acid and nylon 6 fibers
Authors: Cho Ah‐Ra , Shin Dong Myeong , Jung Hyun Wook , Hyun Jae Chun , Lee Joo Sung , Cho Daehwan , Joo Yong Lak
Published: November 2010

Electrospinning experiments for solutions of two polymers with different crystallization rates, polylatic acid (PLA), and nylon 6 solutions have been carried out. Hexafluoroisopropanol (HFIP) was used as a common solvent to dissolve both PLA and nylon 6. Using the fact that nylon 6 has the faster crystallization rate than PLA, the effect of thermal annealing conditions on the crystal structures of two electrospun fibers has mainly been studied via thermal and mechanical analysis. First, optimal conditions for the formation of uniform nanofibers have been determined by observing their morphology and rheological properties. Thermal analysis revealed that PLA as‐spun fiber exhibits cold crystallization due to insufficient crystal growth in spinline. Also, the effect of thermal annealing on the structural change of nylon 6 fibers including the degree of flow‐induced crystallization is totally different from that of PLA fibers. Finally, tensile measurements of annealed fibers show that the ultimate tensile strength and Young's modulus gradually increases with increasing annealing time for both PLA and nylon 6 mats, resulting from the further growth of crystal structures. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Model‐based linear clustering
Authors: Yan Guohua , Welch William J. , Zamar Ruben H.
Published: November 2010

The authors propose a profile likelihood approach to linear clustering which explores potential linear clusters in a data set. For each linear cluster, an errors‐in‐variables model is assumed. The optimization of the derived profile likelihood can be achieved by an EM algorithm. Its asymptotic properties and its relationships with several existing clustering methods are discussed. Methods to determine the number of components in a data set are adapted to this linear clustering setting. Several simulated and real data sets are analyzed for comparison and illustration purposes. The Canadian Journal of Statistics 38: 716–737; 2010 © 2010 Statistical Society of Canada
Optimal estimation in surrogate outcome regression problems
Authors: Duan Xiaogang , Qin Jing , Wang Qihua
Published: November 2010

The authors consider a double robust estimation of the regression parameter defined by an estimating equation in a surrogate outcome set‐up. Under a correct specification of the propensity score, the proposed estimator has smallest trace of asymptotic covariance matrix whether the “working outcome regression model” involved is specified correct or not, and it is particularly meaningful when it is incorrectly specified. Simulations are conducted to examine the finite sample performance of the proposed procedure. Data on obesity and high blood pressure are analyzed for illustration. The Canadian Journal of Statistics 38: 633–646; 2010 © 2010 Statistical Society of Canada
Heterosynaptic enhancement of the excitability of hippocampal mossy fibers by long‐range spill‐over of glutamate
Authors: Uchida Takeshi , Fukuda Satoshi , Kamiya Haruyuki
Published: November 2010

Several classes of ionotropic receptors have been reported to depolarize the axonal membrane of hippocampal mossy fibers. Both kainate receptors and GABAA receptors are localized on axons and/or presynaptic terminals, and these receptors have been known to be activated by synaptically released glutamate and GABA which spill out from the synaptic clefts. However the relative contribution of these two receptors in modulating the excitability of mossy fiber axon was not reported so far. In this study, we revealed that glutamate spilled out from commissural/associational synapses evoked the facilitation of antidromic population spikes of mossy fibers. Increase in amplitude and decrease in latency of population spikes suggest that the number of recruited mossy fibers increases by depolarization of axonal membrane. Application of non‐NMDA receptor antagonist CNQX (10 μM) almost abolished this effect. TBOA (30 μM), an inhibitor of glutamate transporter, prolonged the duration of heterosynaptic facilitation. These results suggest that glutamate released from distant commissural/associational synapses spills out from synaptic cleft and activates the kainate receptors on the mossy fibers of CA3 region, and plays a major role in modulating presynaptic excitability than GABA. © 2010 Wiley Periodicals, Inc.
Nutritional reference values for Opuntia ficus‐indica determined by means of the boundary‐line approach
Authors: Blanco‐Macías Fidel , Magallanes‐Quintanar Rafael , Valdez‐Cepeda Ricardo D. , Vázquez‐Alvarado Rigoberto , Olivares‐Sáenz Emilio , Gutiérrez‐Ornelas Erasmo , Vidales‐Contreras Juan A. , Murillo‐Amador Bernardo
Published: November 2010

Optimum concentrations and/or sufficiency ranges of nutrients are useful for a correct diagnosis and improvement of nutrient status of cultivated plants. To develop boundary‐line approach (BLA) standards for Opuntia ficus‐indica L., a database of N, P, K, Ca, and Mg concentrations in 1‐year‐old cladodes and cladodes fresh‐matter yield was used. The BLA optimum concentrations (associated with estimated maximum yield) for O. ficus‐indica were: N = 13.1 g kg–1, P = 3.2 g kg–1, K = 44.4 g kg–1, Ca = 38.1 g kg–1, and Mg = 17.3 g kg–1. The BLA sufficiency ranges at 95% yield were 8.4–20.3 g kg–1 for N, 2.4–4.2 g kg–1 for P, 38.2–50.8 g kg–1 K, 31.8–45.2 g kg–1 for Ca, and 14.3–20.9 g kg–1 for Mg. The BLA standards are comparable to those obtained in a previous study using compositional‐nutrient‐diagnosis (CND) approach.
Neotyphodium endophytes trigger salt resistance in tall and meadow fescues
Authors: Reza Sabzalian Mohammad , Mirlohi Aghafakhr
Published: November 2010

Infection with Neotyphodium spp. endophytes increases resistance to drought stress and soil mineral imbalances in tall fescue (Festuca arundinacea Schreb. = Lolium arundinaceum (Schreb.) S. J. Darbysh.) and meadow fescue (Festuca pratensis Huds. = Lolium pratense (Huds.) Darbysh.). We hypothesized that resistance of these grasses to salinity stress may also be attributed to endophyte infection. Two tall fescue genotypes, Fa75 and Fa83, and one meadow fescue genotype, Fp60, infected (E+) with their endophytic fungi, Neotyphodium coenophialum (Glenn, Bacon and Hanlin) and N. uncinatum (Glenn, Bacon and Hanlin), respectively, and their noninfected counterparts (E–) were cultured in nutrient solution at three salinity levels of 0, 85, and 170 mM NaCl. Except for genotype Fa75, E+ plants exhibited higher leaf survival rates than E– clones at a high salinity level (170 mM). Root dry matter was higher in E+ than in E– plants, but shoot dry matter was not affected by endophyte infection. This resulted in a lower shoot‐to‐root ratio in E+ plants (1.63) compared with E– plants (2.40). Sodium (Na+) and chloride (Cl–) concentrations were greater in roots of E– than in E+ clones. In shoots, Na+ and Cl– concentrations were not affected by the endophyte. In contrast, E+ plants accumulated more potassium (K+), which resulted in a greater K+ : Na+ ratio in shoots of E+ than in those of E– plants. Our results show that endophyte infection reduced Na+ and Cl– concentrations in tall fescue and meadow fescue roots but increased K+ concentrations in the shoots. Based on these results, we conclude that endophyte‐infected grasses may thrive better in salinity‐stress environments.
Determination of the different components of cadmium short‐term uptake by roots
Authors: Redjala Tanegmart , Sterckeman Thibault , Louis Morel Jean
Published: November 2010

As the various components of the cadmium (Cd) root sink have not been clearly described, there is a need to precisely measure the respective contributions of apoplast and symplast to short‐term root Cd uptake and to explain the linear component of the absorption isotherms. A new method of fractionating Cd in roots was applied to two plant species with contrasting abilities to accumulate Cd: maize (Zea mays) and a Cd‐hyperaccumulating ecotype of alpine pennycress (Noccaea caerulescens). Their roots were exposed for 1 h to increasing concentrations of labeled Cd. Series of desorption baths were used to obtain the root apoplastic Cd in combination with a brief freezing step in liquid nitrogen to separate the intracellular metal from the apoplastic one. The apoplastic uptake accounted for 15% to 82% and for 48% to 96% of the total Cd uptake of maize and of alpine pennycress roots, respectively. In the case of maize, the concentration‐dependent symplastic net flux fitted a biphasic Michaelis‐Menten function, while in the case of alpine pennycress, a Michaelis‐Menten‐plus‐linear function proved a better fit. The second component of the symplastic net flux may reflect absorption through a low‐affinity transport system. Short‐term Cd uptake by roots is dominated by the high‐affinity transport system for exposure concentrations below 1 μM for maize and 0.2 μM for alpine pennycress, while cell‐wall binding prevailed for higher exposure concentrations.
Optically detunable, inductively coupled coil for self‐gating in small animal magnetic resonance imaging
Authors: Korn Matthias , Umathum Reiner , Schulz Jessica , Semmler Wolfhard , Bock Michael
Published: November 2010

An inductively coupled coil concept is presented, which improves the compensation of physiological motion by the self‐gating (SG) technique. The animal is positioned in a conventional volume coil encompassing the whole animal. A small, resonant surface coil (SG‐coil) is placed on the thorax so that its sensitive region includes the heart. Via inductive coupling the SG‐coil amplifies selectively the MR signal of the beating heart. With an optical detuning mechanism, this coupling can be switched off during acquisition of the MR image information, whereas it is active during SG data sampling to provide the physiological information. In vivo experiments on a mouse show an amplification of the SG signal by at least 40%. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Mammalian target of rapamycin complex 1 is involved in differentiation of regenerating myofibers in vivo
Authors: Miyabara Elen H. , Conte Talita C. , Silva Meiricris T. , Baptista Igor L. , Bueno Carlos , Fiamoncini Jarlei , Lambertucci Rafael H. , Serra Carmen S. , Brum Patricia C. , Pithon‐curi Tania , Curi Rui , Aoki Marcelo S. , Oliveira Antonio C. , Moriscot Anselmo S.
Published: November 2010

This work was undertaken to provide further insight into the role of mammalian target of rapamycin complex 1 (mTORC1) in skeletal muscle regeneration, focusing on myofiber size recovery. Rats were treated or not with rapamycin, an mTORC1 inhibitor. Soleus muscles were then subjected to cryolesion and analyzed 1, 10, and 21 days later. A decrease in soleus myofiber cross‐section area on post‐cryolesion days 10 and 21 was accentuated by rapamycin, which was also effective in reducing protein synthesis in these freeze‐injured muscles. The incidence of proliferating satellite cells during regeneration was unaltered by rapamycin, although immunolabeling for neonatal myosin heavy chain (MHC) was weaker in cryolesion+rapamycin muscles than in cryolesion‐only muscles. In addition, the decline in tetanic contraction of freeze‐injured muscles was accentuated by rapamycin. This study indicates that mTORC1 plays a key role in the recovery of muscle mass and the differentiation of regenerating myofibers, independently of necrosis and satellite cell proliferation mechanisms. Muscle Nerve 42: 778–787, 2010
Synthesis of polyimides containing triphenylamine‐substituted triazole moieties for polymer memory applications
Authors: Wang Kun‐Li , Liu Yi‐Liang , Shih I‐Hao , Neoh Koon‐Gee , Kang En‐Tang
Published: November 2010

A series of thermally stable aromatic polyimides containing triphenylamine‐substituted triazole moieties (AZTA‐PI)s were prepared and characterized. The glass transition temperatures (Tg) of the polyimides were found to be in the range of 262–314 °C. The polyimides obtained by chemical imidization had inherent viscosities of 0.25–0.44 dL g−1 in N‐methyl‐2‐pyrrolidinone. The number average molecular weights (Mn) and weight average molecular weights (Mw) were 1.9–3.2 × 104 and 3.2–5.6 × 104, respectively, and the polydispersity indices (PDI = Mw/Mn) were in the range of 1.70–1.78. A resistive switching device was constructed from the 4,4′‐hexafluoroisopropylidenediphthalic dianhydride‐based soluble polyimide (AZTA‐PIa) in a sandwich structure of indium‐tin oxide/polymer/Al. The as‐fabricated device can be switched from the initial low‐conductivity (OFF) state to the high‐conductivity (ON) state at a switching threshold voltage of 2.5 V under either positive or negative electrical sweep, with an ON/OFF state current ratio in the order of 105 at −1 V. The device is able to remain in the ON state even after turning off the power or under a reverse bias. The nonvolatile and nonrewritable natures of the ON state indicate that the device is a write‐once read‐many times (WORM) memory. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Synthesis of a novel graft copolymer with hyperbranched poly(glycerol) as core and “Y”‐shaped polystyrene‐b‐poly(ethylene oxide)2 as side chains
Authors: Pan Mugang , Wang Guowei , Zhang Yannan , Huang Junlian
Published: November 2010

The graft copolymers composed of “Y”‐shaped polystyrene‐b‐poly(ethylene oxide)2 (PS‐b‐PEO2) as side chains and hyperbranched poly(glycerol) (HPG) as core were synthesized by a combination of “click” chemistry and atom transfer radical polymerization (ATRP) via “graft from” and “graft onto” strategies. Firstly, macroinitiators HPG‐Br were obtained by esterification of hydroxyl groups on HPG with bromoisobutyryl bromide, and then by “graft from” strategy, graft copolymers HPG‐g‐(PS‐Br) were synthesized by ATRP of St and further HPG‐g‐(PS‐N3) were prepared by azidation with NaN3. Then, the precursors (Bz‐PEO)2‐alkyne with a single alkyne group at the junction point and an inert benzyl group at each end was synthesized by sequentially ring‐opening polymerization (ROP) of EO using 3‐[(1‐ethoxyethyl)‐ethoxyethyl]‐1,2‐propanediol (EEPD) and diphenylmethylpotassium (DPMK) as coinitiator, termination of living polymeric species by benzyl bromide, recovery of protected hydroxyl groups by HCl and modification by propargyl bromide. Finally, the “click” chemistry was conducted between HPG‐g‐(PS‐N3) and (Bz‐PEO)2‐alkyne in the presence of N,N,N′,N″,N”‐pentamethyl diethylenetriamine (PMDETA)/CuBr system by “graft onto” strategy, and the graft copolymers were characterized by SEC, 1H NMR and FTIR in details. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Easy synthesis and ring‐opening polymerization of 5‐Z‐amino‐δ‐valerolactone: New degradable amino‐functionalized (Co)polyesters
Authors: Blanquer Sebastien , Tailhades Julien , Darcos Vincent , Amblard Muriel , Martinez Jean , Nottelet Benjamin , Coudane Jean
Published: November 2010

Novel 5‐Z‐amino‐δ‐valerolactone (5‐NHZ‐VL) was synthesized with an aim to prepare degradable polyesters and copolyesters having amino pendant groups. Following a straightforward and efficient synthetic pathway, 5‐NHZ‐VL was obtained in only two steps and up to 50% yield. The monomer was fully characterized by 1H NMR, 13C NMR, ESI mass spectrometry, and HPLC. Various conventional conditions were tested for this lactone ring‐opening polymerization and led to the novel corresponding poly(5‐NHZ‐VL) (Mn = 7000 g/mol; PD = 1.2). Following this homopolymerization, 5‐NHZ‐VL was copolymerized with ε‐caprolactone to generate a family of copolyesters with an amino‐group content ranging from 10 to 80%. Finally, the polyelectrolyte poly(5‐NH3+‐VL) was recovered by removal of the protecting group under acidic conditions, and integrity of the polyester backbone was confirmed by 1H NMR. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Metallocene supported on a polyhedral oligomeric silsesquioxane‐modified silica: Structural characterization and catalytic activity for ethylene polymerization
Authors: García‐Orozco Ivan , Velilla Teresa , Galland Griselda B. , dos Santos Joaõ Henrique Z. , Williams Roberto J.J. , Quijada Raúl
Published: November 2010

Preliminary results on the activity of metallocene supported over a polyhedral oligomeric silsesquioxane (POSS)‐modified silica for ethylene polymerization (Bianchini et al., J Polym Sci Part A: Polym Chem 2005, 43, 5465–5476) were extended showing the effect of large variations of the amount of both POSS and metallocene on the catalyst activity. Diffuse reflectance infrared spectroscopy results showed that at low concentrations (<1 wt %), POSS was physically adsorbed on SiOH groups present in the silica surface through H‐bonds. At larger concentrations, POSS was adsorbed by covalent bonds with the silica surface. The metallocene catalyst was adsorbed either on the silica surface by interactions with residual SiOH groups or in the organic branches of the POSS. It was found that the highest contribution to the catalyst activity arose from the metallocene directly adsorbed on the silica support. The effect of POSS to increase the catalyst activity was mainly due to its effect as a horizontal spacer of metallocene molecules adsorbed on the silica surface. An optimum range of POSS and metallocene adsorbed on the silica support was found that gave catalyst activities close to the one of the homogeneous system while doubling the molar mass of the polyethylene produced. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
A novel way to numerically characterize DNA sequences and its application
Authors: Guo Ying , Wang Yan‐fang , Zhang Sheng‐li
Published: November 2010

We presented a novel way to numerically characterize DNA sequences based on the graphical representation for the sequences comparison and analysis. Instead of calculating the leading eigenvalues of the matrix for graphical representation, we computed curvature and torsion of curves as the descriptor to numerically characterize DNA sequences. The new method was tested on three data sets: the coding sequences of β‐globin gene, all of their exons, and 24 coronavirus geneomes from NCBI. The similarities/dissimilarities and phylogenetic tree of these species verify the validity of our method. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Clinical and biomechanical analyses to select a suture material for uvulopalatopharyngeal surgery
Authors: Huang Tsung‐Wei , Cheng Po‐Wen , Chan Yen‐Hui , Wang Chi‐Te , Fang Kai‐Min , Young Tai‐Horng
Published: November 2010

OBJECTIVE

The selection of the degradation pattern of suture materials is critical in uvulopalatopharyngeal surgery because of the complex oral environment such as the constant presence of saliva; the microbial accumulation; and the functions related to speech, mastication, and swallowing. The aim of the study was to identify appropriate suture materials for uvulopalatopharyngeal surgery by analyzing the clinical and biomechanical results obtained using four different absorbable suture materials.

STUDY DESIGN

A randomized open‐label trial.

SETTING

Tertiary referral center.

SUBJECTS AND METHODS

Eighty patients with obstructive sleep apnea syndrome who had undergone microdebrider‐assisted extended uvulopalatoplasty were randomized into the four suture groups: sutures of polyglycolide (Dexon) and copolymers of polyglycolide and other degradable polymers (Polysorb, Monocryl, Maxon). Handling characteristics, surgical outcomes, Young's modulus reduction, morphologic changes by scanning electron microscope, and saliva absorption test were analyzed.

RESULTS

Monocryl (poly(glycolide‐co‐∊‐caprolactone)) had the optimal handling characteristics and exhibited two‐stage degradation: sufficient tensile strength was maintained initially to allow wound healing, and then the suture degraded rapidly to avoid irritation. In contrast, the hydrolytic degradation of Dexon, Polysorb, and Maxon seemed to involve only an approximately single‐stage process in the oral environment. Moreover, a large amount of debris was observed among filaments in Dexon and Polysorb, whereas only some scattered debris accumulated on Monocryl and Maxon under scanning electron microscope.

CONCLUSION

Poly(glycolide‐co‐∊‐caprolactone) has good handling characteristics and degrades in two stages. It is a suitable suture material for uvulopalatopharyngeal surgery.
Assessment of microvascular anastomosis training in otolaryngology residencies: Survey of United States program directors
Authors: Luginbuhl Adam J. , Pribitkin Edmund A. , Krein Howard , Heffelfinger Ryan N.
Published: November 2010

OBJECTIVE

To assess current microvascular training strategies in otolaryngology residency programs.

STUDY DESIGN

Cross‐sectional study.

SETTING

U.S. otolaryngology residency programs.

SUBJECTS AND METHODS

A total of 104 U.S. otolaryngology program directors received surveys inquiring about program size, the presence of fellowship training in microvascular surgery, the number of microvascular cases per month, the use of microvascular animal laboratory, and whether residents, fellows, or co‐attendings assist in the anastomoses.

RESULTS

A 51 percent response rate was achieved, and of the 54 programs that responded, 78 percent reported no microvascular fellowship positions in plastics or head and neck reconstruction. A total of 52 percent reported performing three or fewer microvascular surgeries per month. Of the programs that did not have a microvascular fellow, only five (12%) performed eight or more surgeries per month. A total of 65 percent of the programs reported that residents assist during the anastomosis at least 75 percent of the time. Of the programs where residents assist 75 percent or more of the time, 70 percent have a formal training in microvascular technique ranging from demonstrating laboratory competencies to multiday courses. A total of 48 percent of the responding programs report having an animal laboratory for microvascular surgery. All animal laboratories used the rat as the model.

CONCLUSION

Many programs find value in providing residents with microvascular training, both in the operating room and in the laboratory. Only a small minority of programs without fellowship positions responded that they perform microvascular surgery on a regular basis (4 or more surgeries per month).
Paleoecological and biogeographical implications of late Pleistocene noble marten (Martes americana nobilis) in eastern Washington State, USA
Authors: Lyman R. Lee
Published: November 2010

A mandible identified as noble marten (Martes americana nobilis) recovered from sediments dating to 11,800 cal yr BP and a humerus identified as M. a. cf. nobilis recovered from sediments dating from 13,100 to 12,500 cal yr BP at the Marmes Rockshelter archaeological site in southeastern Washington represent the first record of this taxon in the state. Mammalian taxa associated with the Marmes Rockshelter noble marten represent a diversity of open mesic habitats corroborating earlier analyses of other records of the noble marten in the western United States and exemplify how paleozoologists determine the ecology and environmental predilections of extinct taxa. The recovery site represents the topographically lowest record of this species in western North America and the farthest north record in the United States. Future research should examine known late-Quaternary Martes spp. remains from British Columbia and Alberta to fill in the 2200-km geographic gap in the known distribution of this taxon between a record in the northern Yukon and those in the western United States, and to refine our knowledge of noble marten paleoecology.
Influence of nozzle-exit boundary-layer conditions on the flow and acoustic fields of initially laminar jets
Authors: BOGEY C. , BAILLY C.
Published: November 2010

Round jets originating from a pipe nozzle are computed by large-eddy simulations (LES) to investigate the effects of the nozzle-exit conditions on the flow and sound fields of initially laminar jets. The jets are at Mach number 0.9 and Reynolds number 105, and exhibit exit boundary layers characterized by Blasius velocity profiles, maximum root-mean-square (r.m.s.) axial velocity fluctuations between 0.2 and 1.9% of the jet velocity, and momentum thicknesses varying from 0.003 to 0.023 times the jet radius. The far-field noise is determined from the LES data on a cylindrical surface by solving the acoustic equations. Jets with a thinner boundary layer develop earlier but at a slower rate, yielding longer potential cores and lower centreline turbulent intensities. Adding random pressure disturbances of low magnitude in the nozzle also increases the potential core length and reduces peak r.m.s. radial velocity fluctuations in the shear layer. In all the jets, the shear-layer transition is dominated by vortex rolling-ups and pairings, which generate strong additional acoustic components, but also amplify the downstream-dominant low-frequency noise component when the exit boundary layer is thick. The introduction of inlet noise however results in weaker pairings, thus spectacularly reducing their contributions to the sound field. This high sensitivity to the initial conditions is in good agreement with experimental observations.
A perspective of Batchelor's research in micro-hydrodynamics
Authors: HINCH JOHN
Published: November 2010

Batchelor made his name with research in turbulence in the 1940s and 1950s. He became disillusioned with turbulence at the Marseille meeting in 1961. At the end of the 1960s, he started his second wave of research on low-Reynolds-number suspensions of particles. Ten years after he died, I will describe his key results, what was before and what followed. Eight of his 10 most cited papers are in micro-hydrodynamics.
Local responses to a forest park in western Uganda: alternate narratives on fortress conservation
Authors: Hartter Joel , Goldman Abraham
Published: November 2010

Most research on attitudes to parks in sub-Saharan Africa has been in savannah regions and areas of low population density. Expulsion, exclusion and the imposition of external control are dominant themes, resulting in negative responses to parks, particularly those that represent hard-edged so-called fortress conservation. Our research in the densely populated area around a mid altitude forest park in western Uganda found an alternate narrative in which, despite its hard-edged fortress features, most people view Kibale National Park favourably. Based on a geographically random sample in two agricultural areas neighbouring the Park, our results indicate that most households felt they benefit from the Park and only a small proportion cited negative impacts. Rather than direct economic returns, the benefits most commonly noted by respondents can be characterized as ecosystem services. Most individual respondents and a large majority of the local political leaders said that the Park should continue to exist. Crop raiding by animals from the Park is a problem in some locations but resource restrictions and expulsion were not widely cited by our respondents. The fact that the large majority of residents migrated to the area after the Park was established may be an important explanatory factor for these responses, and this is also likely to be the case for many other mid altitude tropical forest parks, the demographic and land-use histories of which differ from those around many savannah parks.
A CHEBYSHEV PSEUDO-SPECTRAL METHOD FOR SOLVING FRACTIONAL-ORDER INTEGRO-DIFFERENTIAL EQUATIONS
Authors: SWEILAM N. H. , KHADER M. M.
Published: November 2010

A Chebyshev pseudo-spectral method for solving numerically linear and nonlinear fractional-order integro-differential equations of Volterra type is considered. The fractional derivative is described in the Caputo sense. The suggested method reduces these types of equations to the solution of linear or nonlinear algebraic equations. Special attention is given to study the convergence of the proposed method. Finally, some numerical examples are provided to show that this method is computationally efficient, and a comparison is made with existing results.
Temporal variation and climate dependence of soil respiration and its components along a 3000 m altitudinal tropical forest gradient
Authors: Zimmermann Michael , Meir Patrick , Bird Michael I. , Malhi Yadvinder , Ccahuana Adan J. Q.
Published: November 2010

To simulate the effect of temperature on soil respiration rates, we translocated soil cores among four sites (3030, 1500, 1000, and 200 m asl) along an altitudinal tropical forest gradient in the Peruvian Andes, traversing a difference in mean annual temperature of 13.9°C. Rates of total (Rs) and heterotrophic (Rsh) respiration were measured twice a month from April 2007 to March 2009 and additionally for full 24 h periods. The diurnal range in Rs increased with altitude; this variation was mainly root and litter derived, whereas Rsh varied only slightly over full 24 h periods. Although mean annual daytime Rs rates were not significantly different among the four sites (4.45–4.05 μmol CO2 m−2 s−1), the annual amount of respired C decreased with increasing altitude from 1639 g C m−2 yr−1 at 200 m asl to 1064 g C m−2 yr−1 at 3030 m asl. The contribution of Rsh to Rs was not correlated with elevation and ranged from 25% to 60%. The temperature dependence of Rs was lower at the midelevation sites (Q10 of 2.07 and 2.94 at 1500 and 1000 m asl, respectively) than at the highest and lowest sites of the gradient (Q10 of 4.33 and 6.92 at 3030 and 200 m asl, respectively). The temperature sensitivity of Rsh was higher for the sites at 3030 and 200 m asl and increased with time, i.e., with the loss of the most labile C pools.
Solar wind driving of magnetospheric ULF waves: Field line resonances driven by dynamic pressure fluctuations
Authors: Claudepierre S. G. , Hudson M. K. , Lotko W. , Lyon J. G. , Denton R. E.
Published: November 2010

Several observational studies suggest that solar wind dynamic pressure fluctuations can drive magnetospheric ultralow‐frequency (ULF) waves on the dayside. To investigate this causal relationship, we present results from Lyon‐Fedder‐Mobarry (LFM) global, three‐dimensional magnetohydrodynamic (MHD) simulations of the solar wind–magnetosphere interaction. These simulations are driven with synthetic solar wind input conditions where idealized ULF dynamic pressure fluctuations are embedded in the upstream solar wind. In three of the simulations, a monochromatic, sinusoidal ULF oscillation is introduced into the solar wind dynamic pressure time series. In the fourth simulation, a continuum of ULF fluctuations over the 0–50 mHz frequency band is introduced into the solar wind dynamic pressure time series. In this numerical experiment, the idealized solar wind input conditions allow us to study only the effect of a fluctuating solar wind dynamic pressure, while holding all of the other solar wind driving parameters constant. We show that the monochromatic solar wind dynamic pressure fluctuations drive toroidal mode field line resonances (FLRs) on the dayside at locations where the upstream driving frequency matches a local field line eigenfrequency. In addition, we show that the continuum of upstream solar wind dynamic pressure fluctuations drives a continuous spectrum of toroidal mode FLRs on the dayside. The characteristics of the simulated FLRs agree well with FLR observations, including a phase reversal radially across a peak in wave power, a change in the sense of polarization across the noon meridian, and a net flux of energy into the ionosphere.
Correlation between the ionospheric WN4 signature and the upper atmospheric DE3 tide
Authors: Wan W. , Xiong J. , Ren Z. , Liu L. , Zhang M.‐L. , Ding F. , Ning B. , Zhao B. , Yue X.
Published: November 2010

The present work studies the correlation relationship between the longitudinal ionospheric structure of wave number 4 (WN4) and the upper atmospheric tide of nonmigrating tidal mode DE3 (diurnal eastward wave number 3). Global ionospheric maps produced by the Jet Propulsion Laboratory were used to deduce the latitudinal integration of total electron content in the low‐latitude ionosphere, and TIDI/TIMED observations were used to retrieve the atmospheric zonal and meridional winds. By applying Fourier filtering and fitting techniques, the WN4 wave and DE3 tidal components are derived from the ionospheric and upper atmospheric observations, respectively. We found that the observed WN4 wave and DE3 zonal wind components experience very similar annual and interannual variations, but the DE3 meridional wind component behaves in a quite different manner. Both WN4 and DE3 zonal winds are very intense during northern summer and autumn; they also appear in the later spring, but tend to vanish in winter. Their amplitudes increase as the solar activity decreases, and both are stronger in the quasi‐biennial oscillation (QBO) eastward wind phase than in the westward phase. At the same time, the DE3 meridional wind likes to occur only in winter and seems not change with solar activity and QBO phase. We further studied the correlation between the WN4 wave and the two wind components of the DE3 tide. We found that the cross‐correlation coefficient between the WN4 wave and the DE3 zonal wind is much larger, while that between the WN4 wave and the DE3 meridional wind is relatively smaller. Such different correlations are attributed to the different latitudinal symmetry of different DE3 wind components. The DE3 zonal wind is likely in latitudinally symmetric tidal mode; hence, it can efficiently affect the F region ion drifts. In contrast, the meridional wind is mainly in antisymmetric mode and thus seldom affects the ionospheric drifts. The present results support the suggestion that the longitudinal WN4 structure in the ionospheric F region originates from the symmetric modes, mainly the zonal wind component, of the upper atmospheric nonmigrating tidal mode DE3 in the ionospheric E region.
Statistical characteristics and significance of low‐frequency instability associated with magnetic dipolarizations in the near‐Earth plasma sheet
Authors: Park M. Y. , Lee D.‐Y. , Ohtani S. , Kim K. C.
Published: November 2010

Magnetic dipolarization has been considered as a key element of substorm phenomena. In this work we investigate the spectral features of the magnetic dipolarization fluctuations in frequency‐time space by using the continuous wavelet transform technique. We present details of the analysis for three specific examples and the statistical results for 82 magnetic dipolarizations that occurred at X > ∼−11.5 RE in the near‐Earth plasma sheet. We focus on a low‐frequency regime defined here as 0.005 to 0.03 Hz for convenience sake (typically well below local proton gyrofrequency). On the basis of the three specific events, we explicitly demonstrate that the magnetic dipolarization fluctuations can be dominated by intense waves at one or more (typically 2–3) discrete frequencies in the low‐frequency regime. Statistically, we find that this is the case for 59 (about 72%) out of the 82 events. In addition, we find that such a wave starts to grow in amplitude, thus implying occurrence of instability, typically minutes prior to the dipolarization onset time. The estimated exponential growth time is less than 2 min for ∼68% out of the 72% events. The statistically averaged frequency for the strongest wave is ∼0.01Hz, which we argue is in the regime of ballooning instability. All these features are most clearly seen in the compressional component of magnetic fluctuations. For two of the three example events, it is demonstrated that the magnetic fluctuations on the perpendicular plane are linearly polarized for a given frequency while a more comprehensive statistical study of polarization features is left for a future work. On the basis of the results obtained in this work we conclude that the association of low‐frequency instability with substorm‐associated dipolarizations can be quite significant from a statistical viewpoint.
Influence of the Amazon/Orinoco Plume on the summertime Atlantic climate
Authors: Vizy Edward K. , Cook Kerry H.
Published: November 2010

A plume of fresh water forms in the Atlantic due to discharge from the Amazon and Orinoco rivers and creates a stable barrier layer near the surface that is associated with warm sea surface temperature anomalies (SSTAs). The boreal summer atmospheric response to this sea surface temperature (SST) forcing is investigated using a regional atmospheric model. Results from two ensembles, one with the plume SSTA removed, and the other with an idealized plume SSTA imposed, reveal that the scale of the SSTA forcing is large enough to influence the summer climate over the tropical western Atlantic and Central America. Rainfall increases over the SSTAs and downstream over the Caribbean Sea and Central America, as sensible and latent heating associated with the plume SSTAs force a Rossby/Kelvin wave dynamical response. The result is westward shift by 12° of longitude of the North Atlantic subtropical anticyclone, a northward repositioning of the summertime subtropical anticyclone extension over the Gulf of Mexico, and increased moisture convergence into Central America. Warm SSTAs associated with the plume also influence simulated summer tropical Atlantic storms. The presence of the plume increases the number of Atlantic basin storms by 60% (i.e., 4.66 more storms). An increase in storm intensity also occurs, with a 61% increase of the number of storms that reach tropical storm and hurricane strength. However, these storms tend to be shorter lived and are associated with a 12% decrease in the number of tropical storm days. Storm trajectories also shift westward over the western Atlantic associated with the presence of the plume, bringing them closer to the U.S. coast as both the steering winds and vertical wind shear over the Atlantic are modified. These results suggest that the August storm systems may be more likely to track closer to the U.S. coast and/or over the Gulf of Mexico. Since the Amazon and Orinoco rivers are fed primarily by rainfall in the Amazon Basin during austral summer, the influence of the plume SSTs on Atlantic climate is an example of interhemispheric forcing of climate variability across seasons.
Heterotopic pregnancy: incidental finding at laparoscopy after spontaneous abortion
Authors: Casa A. , Montanino‐Oliva M. , De Matteis G. , Primicerio M. , Cirese E.
Published: November 2010

Heterotopic pregnancy is the coexistence of intrauterine and extrauterine pregnancy. Laparoscopy was performed in a woman complaining of abdominal pain, 2 weeks after a spontaneous abortion. During surgery an abdominal implant was discovered and removed. Histological examination showed this to be an abdominal pregnancy. Although the present case was not a life‐threatening condition, it is important to be aware of this rare and potentially deadly condition, even in patients who do not present any risk factors for multiple or ectopic gestation.
Developing mathematical problem solving skills
Authors: Abidin B. , Hartley J.R.
Published: November 2010

Abstract Problem solving often requires a representation of given information in a structured form which can stimulate and support the problem solving process. FunctionLab is a computer based learning environment meeting this requirement and designed to assist problem solving and the development of problem solving skills in algebra word problems. A feature of the system is its interface design which incorporates tools for students to represent problem information as generic and dynamic process models which support investigatory learning and illustrate the structural characteristics of solutions. The design of FunctionLab is described together with an initial evaluation study of its effects on problem solving performances and methods of solution.