bluuebunny/crossref_metadata_2025 huggingface dataset:
Atypical medulloblastoma: A case series
Authors: Meshkini Ali , Vahedi Amir , Meshkini Mohammad , Alikhah Hossein , Naghavi-Behzad Mohammad
Published: April 2014

Medulloblastoma is common in children as a tumor of midline posterior fossa, which arises from vermis and appears as a homogenously enhancing hyperdense mass on computed tomography scan and is associated with the clinical picture of posterior fossa syndrome. This unique clinic-radiological pattern in considered "typical" medulloblastoma, but medulloblastomas does not follow the typical clinic-radiological pattern in a significant number of children and adult cases. We review here the previous reports of atypical or uncommon features of medulloblastoma and add our very rare atypical cases of medulloblastomas to this list. Medulloblastoma should be considered in all midline posterior fossa tumors, hemisphere and cerebellopontine angle despite having clinical and radiological features suggestive of other tumors. Definitive diagnosis requires histologic confirmation in all cases.
Giant cell tumor of the clivus with presence of epithelioid histiocytes
Authors: Agrawal Amit , Gali Rajsekhar , Shanthi Vissa , Ramakrishna Baddukonda , Mohan Kuppili Venkata
Published: April 2014

Giant cell tumor (GCT) is a benign neoplasm but locally aggressive tumor that uncommonly involves the skull bone. We report a case of a 62-year-old male presented with increasing headache and diplopia. Investigations were suggestive of an expanding mass lesion of the clivus. Histopathology was suggestive of diagnosed with GCT with abundant histiocytes.
Tetrylenes chelated by bifunctional β‐diketiminate ligand: structure and possible applications
Authors: Olejník Roman , Padělková Zdeňka , Mundil Robert , Merna Jan , Růžička Aleš
Published: April 2014

The synthesis and structure of heteroleptic tetrylenes containing bifunctional β‐diketiminate ligand are reported. Compounds were prepared via a protolytic reaction of free β‐diketimine {N‐[(2‐MeO)C6H5]}N═C(Me)CH═C(Me)N(H){N′‐[(2‐MeO)C6H5]} (LCOH) and {N‐[(2‐MeO)C6H5]}NCHCHCHN(H){N′‐[(2‐MeO)C6H5]} (LHOH), respectively, with corresponding bis(amide) – M[N(SiMe3)2]2 (M = Ge, Sn, Pb) – in equimolar ratio or via the salt elimination route from lithium precursors generated from LHOH/LCOH species and slight excess of SnCl2 or GeCl2.dioxane complex. Only heteroleptic complexes were obtained by the mentioned methods. Products were characterized by multinuclear NMR spectroscopy techniques and structures of four of them have been determined by X‐ray diffraction methods. Complexes LHOGeCl and LCOSnN(SiMe3)2 crystallize as monomers with the three‐coordinated metal centres by one chloro or amido ligand and one bidentate β‐diketiminato unit, in contrast to the structure of LCOSnCl, which reveals a dimeric character and compound LCOPbN(SiMe3)2, where the central atom of lead is five‐coordinated by methoxy groups of the ligand. Complex LCOSnN(SiMe3)2 was tested as a catalyst for polymerization of various epoxides. Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis, characterization, and properties of biodegradable poly(butylene succinate) modified with imide dihydric alcohol
Authors: He Wen , Lan Jianwu , Huang Xia , Shang Jiaojiao
Published: April 2014

A series of high molecular weight poly (butylene succinate) and its copolyester containing rigid imide units were synthesized in this article. The chemical structure and composition of the copolyesters were determined by 1H NMR spectroscopy and Fourier transform infrared spectroscope (FT‐IR). The thermal properties, crystallization behavior and mechanical properties of polymers were investigated using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide‐angle X‐ray diffraction (WAXD) and mechanical testing. The enzymatic degradation was investigated using pancreatic lipase solution. The results showed that the melting temperature (Tm) of the copolyester decreased with the increment in pyromellitic imide unit content. However, the thermal degradation temperature (5% decomposition temperature) changed little. Meanwhile, the enzymatic degradation rate of poly (butylene succinate) was enhanced. The mechanical properties showed that the tensile strength had a trend of decrease, but the elongation at break was improved with the increment in imide units. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40807.
DIETARY LUFENURON REDUCES EGG HATCH AND INFLUENCES PROTEIN EXPRESSION IN THE FRUIT FLY Bactrocera latifrons (HENDEL)
Authors: Chang Chiou Ling , Geib Scott , Cho Il Kyu , Li Qing X. , Stanley David
Published: April 2014

Lufenuron (LFN), a chitin synthase inhibitor, impacts the fertility of Ceratitis capitata, Bactrocera dorsalis, B. cucurbitae, and B. latifrons. We posed the hypothesis that LFN curtails egg hatch in the solanaceous fruit fly, B. latifrons. In this study, newly emerged virgin adults were sexed and fed for 12 days with varying concentrations of LFN‐laced agar diets until sexual maturation. Eggs were collected from 12‐d‐old adults and the egg hatch was assessed. Egg hatch decreased in adults reared on LFN‐treated diets. LFN‐treated media did not influence fertility after one gender was reared on experimental and the other on control media before mating. Exposure to LFN‐treated medium after mating led to reduced egg hatch. We infer that LFN is not a permanent sterilant, and reduced egg hatch depends on continuous exposure to dietary LFN after mating. Proteomic analysis identified two differentially expressed proteins, a pheromone binding protein and a chitin binding protein, between adults maintained on LFN‐treated and control diets. Expression of two genes encoding chitin synthase 2, and chitin binding protein, was altered in adults exposed to dietary LFN. LFN treatments also led to increased expression of two odorant binding proteins one in females and one in males. We surmise these data support our hypothesis and provide insight into LFN actions.
Visual representation of information as communicative practice
Authors: Snyder Jaime
Published: April 2014

Anyone who has clarified a thought or prompted a response during a conversation by drawing a picture has exploited the potential of image making to convey information. Images are increasingly ubiquitous in daily communication due to advances in visually enabled information and communication technologies (ICT), such as information visualization applications, image retrieval systems, and virtual collaborative work tools. Although images are often used in social contexts, information science research concerned with the visual representation of information typically focuses on the image artifact and system building. To learn more about image making as a form of social interaction and as a form of information practice, a qualitative study examined face‐to‐face conversations involving the creation of ad hoc visualizations (i.e., “napkin drawings”). Interactional sociolinguistic concepts of conversational involvement and coordination guided multimodal analysis of video‐recorded interactions that included spontaneous drawing. Findings show patterns in communicative activities associated with the visual representation of information. Furthermore, the activity of mark making contributes to the maintenance of conversational involvement in ways that are not always evident in the drawn artifact. This research has implications for the design and evaluation of visually enabled virtual collaboration environments, visual information extraction and retrieval systems, and data visualization tools.
Gastrointestinal Dysfunction in Children With Autism Spectrum Disorders
Authors: Kang Victor , Wagner George C. , Ming Xue
Published: April 2014

Gastrointestinal (GI) dysfunctions are frequently reported by parents of children with autism spectrum disorders (ASD) and have been recently recognized as a comorbid condition. However, the clinical significance of these GI dysfunctions remains to be delineated. This study describes the clinical characteristics, associated comorbid disorders, and endoscopic and colonoscopic evaluation of GI dysfunction in a cohort of 164 children with ASD evaluated at a pediatric neurology practice. Symptoms of GI dysfunction were prevalent: 49% of the children reported one or more chronic GI complaints, 22% exhibited diarrhea, 26% suffered from constipation. Furthermore 13% of the parents reported their children to suffer from bloating and/or being gassy and while 10% of the parents reported vomiting or gastroesophageal reflux problems. Similar rates of GI symptoms were reported among pre‐school and school‐aged children. Inflammation of the gut was found in 6 of the 12 subjects who underwent endoscopic and colonoscopic evaluations, however clinical symptoms did not predict the results of the evaluation. GI dysfunction was significantly associated with sleep disorders and food intolerance, but not with irritability or aggressiveness. In summary, GI dysfunction was prevalent in this cohort of children with ASD, observations consistent with the reports of parents and other clinicians. We conclude that the GI dysfunction in ASD requires proper evaluation and treatment. Autism Res 2014, 7: 501–506. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.
Endocannabinoids and energy homeostasis: An update
Authors: Cristino Luigia , Becker Thorsten , Di Marzo Vincenzo
Published: April 2014

The endocannabinoid system (ECS) is a widespread intercellular signaling system that plays a critical role in energy homeostasis, meant as the precise matching of caloric intake with energy expenditure which normally keeps body weight stable over time. Complex interactions between environmental and neurohormonal systems directly contribute to the balance of energy homeostasis. This review highlights established and more recent data on the brain circuits in which the ECS plays an important regulatory role, with focus on the hypothalamus, a region where numerous interacting systems regulating feeding, satiety, stress, and other motivational states coexist. Although not meant as an exhaustive review of the field, this article will discuss how endocannabinoid tone, in addition to reinforcing reward circuitries and modulating food intake and the salience of food, controls lipid and glucose metabolism in several peripheral organs, particularly the liver and adipose tissue. Direct actions in the skeletal muscle and pancreas are also emerging and are briefly discussed. This review provides new perspectives into endocannabinoid control of the neurochemical causes and consequences of energy homeostasis imbalance, a knowledge that might lead to new potential treatments for obesity and related morbidities. © 2014 BioFactors, 40(4):389–397, 2014
GC Separation of Enantiomers of Alkyl Esters of 2‐Bromo Substituted Carboxylic Acids Enantiomers on 6‐TBDMS‐2,3‐di‐alkyl‐ β‐ and γ‐Cyclodextrin Stationary Phases
Authors: Špánik Ivan , Kačeriaková Darina , Krupčík Jan , Armstrong Daniel Wayne
Published: April 2014

The gas chromatographic separation of enantiomers of 2‐Br carboxylic acid derivatives was studied on four different 6‐TBDMS‐2,3‐di‐O‐alkyl‐ β‐ and ‐γ‐CD stationary phases. The differences in thermodynamic data {ΔH and –ΔS} for the 15 structurally related racemates were evaluated. The influence of structure differences in the alkyl substituents covalently attached to the stereogenic carbon atom, as well as in the ester group of the homologous analytes, and the selectivity of modified β‐ and γ‐ cyclodextrin derivatives was studied in detail. The cyclodextrin cavity size, as well as elongation of alkyl substituents in positions 2 and 3 of 6‐TBDMS‐β‐CD, also affected their selectivity. The quality of enantiomeric separations is influenced mainly by alkyl chains of the ester group of the molecule and this appears to be independent of the CD stationary phase used. In some cases the separations occur as the result of external adsorption rather than inclusion complexations with the chiral selector. It was found that the temperature dependencies of the selectivity factor were nonlinear. Chirality 26:279–285, 2014. © 2014 Wiley Periodicals, Inc.
Sub‐second proton imaging of 13C hyperpolarized contrast agents in water
Authors: Truong Milton L. , Coffey Aaron M. , Shchepin Roman V. , Waddell Kevin W. , Chekmenev Eduard Y.
Published: April 2014

Indirect proton detection of 13C hyperpolarized contrast agents potentially enables greater sensitivity. Presented here is a study of sub‐second projection imaging of hyperpolarized 13C contrast agent addressing the obstacle posed by water suppression for indirect detection in vivo. Sodium acetate phantoms were used to develop and test water suppression and sub‐second imaging with frequency‐selective RF pulses using spectroscopic and imaging indirect proton detection. A 9.8 mm aqueous solution of 13C PHIP hyperpolarized 2‐hydroxyethyl‐13C‐propionate‐d2,3,3 (HEP),  ~25% was used for demonstration of indirect proton sub‐second imaging detection. Balanced 2D FSSFP (fast steady‐state free precession) allowed the recording of proton images with a field of view of 64 × 64 mm2 and spatial resolution 2 × 2 mm2 with total acquisition time of less than 0.2 s. In thermally polarized sodium 1‐13C‐acetate, 13C to 1H polarization transfer efficiency of 45.1% of the theoretically predicted values was observed in imaging detection corresponding to an 11‐fold overall sensitivity improvement compared with direct 13C FSSFP imaging. 13C to 1H polarization transfer efficiency of 27% was observed in imaging detection, corresponding to a 3.25‐fold sensitivity improvement compared with direct 13C FSSFP imaging with hyperpolarized HEP. The range of potential applications and limitations of this sub‐second and ultra‐sensitive imaging approach are discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Nonblocking collectives for scalable Java communications
Authors: Ramos Sabela , Taboada Guillermo L. , Expósito Roberto R. , Touriño Juan
Published: April 2014

This paper presents a Java implementation of the recently published MPI 3.0 nonblocking message passing collectives in order to analyze and assess the feasibility of taking advantage of these operations in shared memory systems using Java. Nonblocking collectives aim to exploit the overlapping between computation and communication for collective operations to increase scalability of message passing codes, as it has been carried out for nonblocking point‐to‐point primitives. This scalability has become crucial not only for clusters but also for shared memory systems because of the current trend of increasing the number of cores per chip, which is leading to the generalization of multi‐core and many‐core processors. Message passing libraries based on remote direct memory access, thread‐based progression, or implementing pure multi‐threading shared memory support could potentially benefit from the lack of imposed synchronization by nonblocking collectives. But, although the distributed memory scenario has been well studied, the shared memory one has not been tackled yet. Hence, nonblocking collectives support has been included in FastMPJ, a Message Passing in Java (MPJ) implementation, and evaluated on a representative shared memory system, obtaining significant improvements because of overlapping and lack of implicit synchronization, and with barely any overhead imposed over common blocking operations. Copyright © 2014 John Wiley & Sons, Ltd.
Design and analysis of an improved smartcard‐based remote user password authentication scheme
Authors: Islam SK Hafizul
Published: April 2014

With the fast development of the Internet and the telecommunication technologies, internet users are carrying out various electronic transactions over internet by means of the authentication protocols. To ensure efficient and robust online transaction, security of authentication protocol turns out to be a great concern nowadays. As a result, smartcard‐based password authentication and session key agreement scheme receives significant attention in recent years. In the literature, various authentication schemes have been proposed by the cryptographic research community. Recently, Li et al. analyze some security weaknesses of the authentication scheme of Chen et al. and propose an enhancement based on the discrete logarithm problem and computational Diffie–Hellman problem. This paper further cryptanalyzes the scheme of Li et al. and identifies various security loopholes and then constructs a modified authentication scheme as a remedy. The security and efficiency evaluations demonstrate that our scheme has more security features and low computation costs than the related schemes. Copyright © 2014 John Wiley & Sons, Ltd.
Development and Control of Multi‐Degree‐of‐Freedom Mobile Robot for Acquisition of Road Environmental Modes
Authors: Murata Naoya , Katsura Seiichiro
Published: April 2014

The acquisition of information about the environment around a mobile robot is important for purposes such as controlling the robot from a remote location and in situations such as that when the robot is running autonomously. In some research, audiovisual information has been used. However, the acquisition of information about force sensation, which is included in environmental information, has not been well investigated. The mobile‐hapto, which is a remote control system with force information, has been proposed, but the robot used for the system can acquire only the horizontal components of forces. For this reason, in this research a three‐wheeled mobile robot consisting of seven actuators was developed and a control system was created for it. The robot can acquire information about horizontal and vertical forces without using force sensors. By using this robot, detailed information on the forces in the environment can be acquired and the operability of the robot and its ability to adjust to the environment are expected to improve.
Relationship Between Reaction Rate of Perfluorocarboxylic Acid Decomposition at a Plasma–Liquid Interface and Adsorbed Amount
Authors: Matsuya Yuriko , Takeuchi Nozomi , Yasuoka Koichi
Published: April 2014

Perfluorooctanoic acid (PFOA: C7F15COOH) in water is effectively decomposed by plasma generated at a gas–liquid interface. During the decomposition of PFOA, perfluorocarboxylic acids (PFCAs: ) with shorter carbon chains (n = 1–6) are generated as by‐products. Since these PFCAs are surfactants, they are adsorb onto the gas–liquid interface and show high surface concentrations. This study investigated the relationship between the adsorbed amount of PFCA and the rate of decomposition by a direct current plasma. The adsorbed amount of PFCA at the gas–liquid interface increased as the length of the carbon chain increased, resulting in a higher rate of decomposition. However, the reaction rate reached saturation at a certain adsorption amount, depending on the discharge current.
Electrical Breakdown and Space Charge Formation at High‐Temperature Region in Long‐Time Heating Treatment PVC
Authors: Miura Masakazu , Fukuma Masumi , Kishida Satoru
Published: April 2014

Polyvinyl chloride (PVC) is widely used as an insulating material in various electrical products. It is reported that an exothermic reaction reaching temperatures above 150 °C can be caused by overload currents or inferior electrical wire connections before the ignition of electrical products. The exothermic phenomenon may cause deterioration of insulating properties in PVC due to its chemical decomposition. It is necessary to clarify the degradation of insulating properties in PVC under thermal stress exceeding 150 °C for the safe use of electric products. In this investigation the space charge distribution and conduction current in the heat‐treated PVC sheet were measured in the range from room temperature to 200 °C in the presence of a dc electric field, using a high‐temperature PEA system. Positive charge injection and increasing conduction currents were observed before breakdown above 100 °C in 100 °C 300‐h heat‐treated samples and in non–heat‐treated samples. The results indicate the thermal breakdown process from the analysis of conduction currents and electric fields. In samples exposed to higher temperatures (150 °C 100 h), the breakdown strength deteriorated strongly in the range from room temperature to 90 °C. Increases in conduction current were observed in the entire temperature range before breakdown of the 150 °C 100‐h heat‐treated PVC. This indicates that heat treatment above 150 °C degrades the breakdown properties in the range from room temperature to 90 °C due to thermal decomposition accompanied by dehydrochlorination in PVC. The electric field is intensified near the cathode due to positive charge accumulation, and the breakdown strength begins to deteriorate only above 90 °C. This shows that thermal stress exceeding 150 °C causes deterioration of insulating properties and that the breakdown process is affected by space charge formation in PVC.
Experimental Study of Islanding‐Prevention Method by Harmonic Injection Synchronized with Exciting Current Harmonics of Pole Transformer
Authors: Yoshida Yoshiaki , Suzuki Hirokazu , Fujiwara Koji , Ishihara Yoshiyuki
Published: April 2014

As distributed generators (DGs) such as photovoltaic (PV) systems are increasingly used in distribution systems, quick prevention of islanding caused by power system failure is essential to assure electrical safety. Various islanding protection methods have been used practically, but the conventional active systems tend to increase the detection time, because mutual interference occurs between active signals due to asynchronous states. A new active islanding detection method, the frequency feedback method with step reactive power injection, also has the possibility of extending the detection time in the so‐called perfect balance area (PBA). Thus we propose a novel method of islanding‐prevention by harmonic injection synchronized with the exciting current harmonics of the pole transformer. We performed an experimental study using prototype inverters equipped with the proposed method. We have shown the feasibility of detecting islanding quickly and reliably, even if the islanding state is in the PBA. The experimental results demonstrate that mutual interference does not occur due to asynchronous states between active signals, and also that the proposed method is applicable to islanding detection system in clustered installation of PV systems.
A green route to synthesize layered double hydroxides
Authors: Zhang Yuchao , Wang Juan , Liu Xunjun , Gao Pengran , Gong Chunxia , Lei Lixu
Published: April 2014

This article demonstrates a green route for synthesis of Ca‐doped [Mg3Al(OH)8]Cl from a reaction of AlCl3·6H2O, Mg(OH)2, Ca(OH)2, and NH3·H2O in water, which produces only the desired solid product and a by‐product NH4Cl in the mother solution; therefore, they can be separated easily by filtration or centrifugation. Being carefully designed, enough NH4Cl can be crystallized from the mother solution, which could be used as a fertilizer; while the distilled water be used to wash the products for the last time; the mother solution that still contains some NH4Cl and filtrate from the first time washing of the product can be used to prepare the LDH again. By using cheaper Mg(OH)2 and Ca(OH)2 instead of MgCl2·6H2O and CaCl2·2H2O, the process is more economic and produces less NH4Cl. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 234–239, 2015
Influence of root characteristics and soil variables on the uprooting mechanics of Avena sativa and Medicago sativa seedlings
Authors: Edmaier Katharina , Crouzy Benoît , Ennos Roland , Burlando Paolo , Perona Paolo
Published: April 2014

The success of seedlings and rejuvenated woody debris growing on river bedforms depends on the resistance to uprooting by flow provided by their simple root architecture. Avena sativa and Medicago sativa seedlings were used in flume experiments as prototypes for juvenile riparian plants. Very little is known about the magnitude of root anchoring forces and the role of secondary roots of such simple root systems.

We performed 1550 vertical uprooting experiments on Avena sativa and Medicago sativa seedlings grown in quartz sand. Seedlings were pulled up by direct traction using a wheel driven by a computer‐controlled motor and the force was recorded. Roots were scanned and architectural parameters (root length and number of roots) determined. Uprooting force and work (the integral of the applied force times the distance over which it is applied) were then related to root architecture and soil variables.

Resistance to uprooting increased with decreasing sediment size and sediment moisture content. The initial response of the root–soil system to uprooting showed linear elastic behaviour with modulus increasing with plant age. While the maximum uprooting force was found to increase linearly with total root length and be mainly dependent on the length of the main root, uprooting work followed a power law and has to be related to the whole root system. Thus, for the young plants we considered, secondary roots are responsible for the ability to withstand environmental disturbances in terms of duration rather than magnitude. This distinction between primary and secondary roots can be of crucial importance for seedlings of riparian species germinating on river bars and islands where inundation is a main cause of mortality. Beyond clarifying the biomechanical role of soil and root variables, the uprooting statistics obtained are useful in interpreting and designing ecomorphodynamic flume experiments. Copyright © 2014 John Wiley & Sons, Ltd.
Modeling planform evolution of a mud‐dominated meandering river: Quinn River, Nevada, USA
Authors: Matsubara Yo , Howard Alan D.
Published: April 2014

A depth‐averaged linearized meander evolution model was calibrated and tested using the field data collected at the Quinn River in the Black Rock Desert, Nevada. Two approaches used to test the model were: (1) simulating meander evolution and comparing the results with the observed 38 year migration pattern; and (2) fitting the model parameters to present bank asymmetry (the ratio of the maximum bank gradients on opposite sides of the channel). The data required as input were collected in the field during a high flow in May 2011 and from aerial photographs and LiDAR data. Both approaches yielded similar results for the best fit parameter values. The bank asymmetry analysis showed that the bank asymmetry and the velocity perturbation have high correlation at close to zero spatial lag while the maximum correlation between the bank asymmetry and maximum bend curvature is offset by about 25 m. The model sufficiently replicated 38 years of channel migration, with a few locations significantly under‐ or over‐predicted. Inadequacies of the flow model and/or variation in bank properties unaccounted for are most likely the causes for these discrepancies. Flow through the Quinn River was also simulated by a more general 3D model. The downstream pattern of near‐bank shear stresses simulated by the 3D model is nearly identical to those resulting from the linearized flow model. Topographic profiles across interior bends are essentially invariant over a wide range of migration rates, suggesting that the traditional formulation that cut bank erosion processes govern migration rates is appropriate for the Quinn River. Copyright © 2014 John Wiley & Sons, Ltd.
On multiple‐access relay channel with common message
Authors: Osmani‐Bojd Mohammad , Hodtani Ghosheh Abed
Published: April 2014

In this paper, we obtain a general achievable rate region for discrete memoryless multiple‐access relay channel (DM‐MARC) with common message via partial decode and forward strategy and regular block Markov encoding/backward decoding. This general achievable rate region, as an extension of the achievability part of the relay channel via partial decode and forward strategy to the MARC, subsumes the previous known achievable rate regions for multiple‐access channel with common message and MARC. Also, by applying Fano's inequality, we derive an outer bound for DM‐MARC with common message. By extending the discrete alphabet results to the continuous alphabet, an inner bound for Gaussian MARC (GMARC) is achieved. As expected, our results for the Gaussian MARC includes the previous results for the Gaussian multiple‐access channel with and without common message and the Gaussian relay channel as special cases. Finally, by considering a specific topology for MARC, performance of GMARC with common message versus the position of the relay is investigated numerically. Also, it is shown that our achievable rate region is larger than the previous rate region of GMARC with common message with irregular encoding/successive decoding. Copyright © 2014 John Wiley & Sons, Ltd.
A compressive sensing‐based approach to end‐to‐end network traffic reconstruction utilising partial measured origin‐destination flows
Authors: Nie Laisen , Jiang Dingde , Guo Lei
Published: April 2014

Traffic matrices describe the volume of traffic flowing from origin nodes to destination nodes. As one of the most crucial input parameters for network activities, it is employed to perform a great number of network management tasks. However, traffic matrix estimation is unavailable and has a highly ill‐posed nature, which means that it is significantly difficult to ensure the accuracy for estimating traffic matrices. Thus, it is a challenge to obtain the precise end‐to‐end network traffic. In this paper, we investigate the problem of network traffic estimation and propose a novel compressive sensing‐based approach using partial measured origin‐destination (OD) flows. As a purely data‐driven method, we first propose a strategy to select a small subset of the measured OD flows. We then put forward an optimal greedy adaptive dictionary learning algorithm in order to make the traffic matrix sparse. Furthermore, we model the traffic matrix estimation problem by a fundamental inference problem, which is ill‐posed and obeys the constraints of compressive sensing. In other words, the estimation model is a convex optimisation problem. In the process, we validate the performance of our method by real traffic data. Simulation results indicate that our method can trace the shape of each OD flow much more precisely. Copyright © 2014 John Wiley & Sons, Ltd.
Ant mounds as a source of sediment in a tropical rainforest?
Authors: Schmidt Lena Katharina , Zimmermann Alexander , Elsenbeer Helmut
Published: April 2014

In Lutzito catchment on Barro Colorado Island, Panama, extraordinarily high suspended‐sediment yields of 1–2 Mg ha−1 year−1 were generated despite the dense forest cover coinciding with erosion‐resistant soils. We hypothesized that ant mounding activity is an important zoogeomorphological mechanism in this area, providing relevant quantities of easily transportable material at the soil surface. To test this hypothesis, all ant mound material was collected collected for dry mass determination from thirty 4 m2 plots installed in the study area every 1–3 days during the 39‐day sampling period. Additionally, three ground‐nesting ant species responsible for mounds in the study area, Ectatomma ruidum, Trachymyrmex cornetzi and Strumigenys marginiventris, were identified. On the basis of the total of 1.38 kg of material collected in the wet season of 2011, the estimate for the whole 8 months wet season amounts to 725 kg ha−1. As this value is in the same order of magnitude as sediment output, it shows that ants may act as important ecosystem engineers and contribute to sediment production here by providing large quantities of fine‐grained, readily erodible material at the soil surface for subsequent transport to the streambed. Copyright © 2014 John Wiley & Sons, Ltd.
On the induced‐fit mechanism of substrate‐enzyme binding structures of nylon‐oligomer hydrolase
Authors: Baba Takeshi , Harada Ryuhei , Nakano Masayoshi , Shigeta Yasuteru
Published: April 2014

We present a detailed computational investigation of the induced‐fit motion in a nylon‐oligomer hydrolase (NylB) upon substrate binding. To this aim, we resort on the recently introduced parallel cascade selection molecular dynamics approach, allowing for an accelerated access to the set of conformational changes from an open‐ to a closed‐state structure to form the enzyme‐substrate complex in a specific induce‐fit mechanism. The structural investigation is quantitatively complemented by free energy analyses within the umbrella sampling algorithm accompanied by weighted histogram analysis. We find that the stabilization free energy is about 1.4 kcal/mol, whereas the highest free energy barrier to be overcome is about 2.3 kcal/mol. Conversely, the energetic contribution for the substrate binding is about 20 kcal/mol, as estimated from Generalized Born/Surface Area. This means that the open‐close induced‐fit motion could occur frequently once the substrate binds to the open state of NylB. © 2014 Wiley Periodicals, Inc.
Efficacy of occlusion of hepatic artery and risk of carbon dioxide gas embolism during laparoscopic hepatectomy in a pig model
Authors: Makabe Kenji , Nitta Hiroyuki , Takahara Takeshi , Hasegawa Yasushi , Kanno Shoji , Nishizuka Satoshi , Sasaki Akira , Wakabayashi Go
Published: April 2014

Background

The important point in safely performing laparoscopic hepatectomy (LH) is to control bleeding. The aims of this study were: (i) to assess the bleeding reduction effect by occlusion of the hepatic artery in LH; and (ii) to evaluate the risk of carbon dioxide (CO2) gas embolism (GE) in the case of high pneumoperitoneum (PP).

Methods

Nine piglets underwent laparoscopic left medial lobe and left lateral lobe resection, receiving either occlusion of the hepatic artery (hepatic artery clamping group: HACG, n = 9) or no occlusion (hepatic artery declamping group: HADCG, n = 9) using a PP of 15 mmHg. In addition, we observed changes in hemodynamics induced by PP. The state of GE was observed using transesophageal echocardiography (TEE) during LH (n = 8). GE was graded as grade 0 (none), grade 1 (minor), and grade 2 (major).

Results

The HACG had significantly less bleeding compared to the HADCG (P < 0.01). During LH, four animals showed grade 1 (37.5%) and one animal showed grade 2 (12.5%) GE at 15 mmHg. At 20 mmHg, all animals showed grade 2 (100%) GE.

Conclusion

The occlusion of the hepatic artery in LH reduces blood loss. The control of bleeding from the hepatic vein is feasible with a high PP, but there is a possibility of GE.
Facile Synthesis of Pyrazoline Derivatized Amides via Sydnone Ring Cleavage
Authors: Taj Tasneem , Kamble Ravindra R. , Marganakop Sheetal B.
Published: April 2014

In the present investigation, we have utilized 3‐[3′‐(5″‐aryl‐2″‐pyrazolin‐3″‐yl)]phenylsydnones 1a–c to couple two biodynamic moieties in amide derivatives 7, 8, 9, 10. The compounds 1a–c were brominated to 4‐bromo‐3‐[3′‐(5″‐aryl‐2″‐pyrazolin‐3″‐yl)]phenylsydnone 2, which were further reacted with secondary amines to form the title compounds. These novel molecules were subjected to antitubercular activity against Mycobacterium tuberculae (H37Rv) and antioxidant activity assay.
Microwave and Ultrasound‐Assisted Synthesis of Thiosemicarbazones and Their Corresponding (4,5‐Substituted‐thiazol‐2‐yl)hydrazines
Authors: Carradori Simone , Secci Daniela , D'Ascenzio Melissa , Chimenti Paola , Bolasco Adriana
Published: April 2014

Hantzsch cyclization of thiosemicarbazone intermediates is a very popular approach to the synthesis of substituted thiazoles. We developed a convenient microwave and ultrasound‐assisted method both for the synthesis of 1‐(alkyliden/cycloalkyliden/aryliden)thiosemicarbazone intermediates and their cyclization into (4,5‐substituted‐thiazol‐2‐yl)hydrazines. The search for optimal reaction conditions included the use of different catalysts (Lewis acids and resins) and solvents at discrete temperatures, pressures, and irradiation powers. Comparing yields, reaction times, and efforts proved that microwave and ultrasound‐assisted techniques outmatch conventional heating and have a remarkable influence on the synthesis.
Short Synthesis of Enantiopure Thieno[2,3‐f]triazolo[1,5‐a][1,4]diazepines and Thieno[2,3‐f][1,4]diazepin‐5‐ones
Authors: Molteni Giorgio
Published: April 2014

Starting from 2‐carboxy‐3‐thenylazide 1 and enantiopure amines 2 as the chiral building blocks, we developed a two‐step synthesis of the title compounds involving an intramolecular azide cycloaddition as the key step.
Convenient and Industrially Viable Process for Preparation of Zolmitriptan
Authors: Neelakandan K. , Manikandan H. , Santosha N. , Prabhakaran B.
Published: April 2014

The present invention provides a convenient and industrially viable process for preparation of zolmitriptan. The invention specifically relates to a method for obtaining (S)‐4‐(4‐hydrazinobenzyl)‐1,3‐oxazolidin‐2‐one hydrochloride of desired purity by separation and isolation in a particular pH range to give higher yield and purity.
Design, Synthesis, and Herbicidal Activities of 3‐Aryl‐4‐substituted‐5‐[3‐(trifluoromethyl)phenoxy]‐1,2,4‐triazoles
Authors: Liu Man‐Yun , Shi De‐Qing
Published: April 2014

In order to find novel bleaching herbicide lead compounds, a series of novel 3‐aryl‐4‐substituted‐5‐[3‐(trifluoromethyl)phenoxy]‐1,2,4‐triazoles were designed and synthesized by the multi‐step reactions. N‐(Arylformamido)phenylthioureas undergo ring closure in the presence of sodium hydroxide to generate 3‐aryl‐4‐substituted‐4H‐[1,2,4]triazol‐5‐thiols 1, which reacted with methyl sulfate in the presence of K2CO3 to give 3‐aryl‐5‐methylsulfanyl‐4‐substituted‐4H‐[1,2,4]triazoles 2. The target compounds 4 were synthesized by the oxidation of 2 in the presence of H2O2 and Na2WO4, followed by the substitution with 3‐(trifluoromethyl)phenol in moderate to good yields. Their structures were confirmed by IR, 1H NMR, EI–MS, and elemental analyses. The preliminary bioassay indicated that some of them displayed moderate to good selective herbicidal activity against Brassica campestris L at the concentration of 100 µg/mL. Compounds 4c and 4i possessed 75.0% and 82.6% inhibition against Brassica campestris L at the concentration of 100 µg/mL. However, the target compounds 4 showed weak herbicidal activity against Echinochloa crus‐galli at the concentration of 100 and 10 µg/mL.
Synthesis and Herbicidal Activities of 3‐Trifluoromethyl‐5‐[3‐(trifluoromethyl)phenoxy]‐1,2,4‐Triazol‐4‐Schiff Bases
Authors: Zhang Han‐Yun , Shi De‐Qing
Published: April 2014

In order to find novel bleaching herbicide lead compounds, a series of novel 3‐(trifluoromethyl)‐4‐(arylimino)‐5‐[3‐(trifluoromethyl)phenoxy]‐1,2,4‐triazoles were designed and synthesized by the multi‐step reactions. Their structures were confirmed by IR, 1H NMR, EI‐MS and elemental analyses. The preliminary bioassay indicated that compounds 4b, 4f, and 4h possessed 69.4%, 72.6%, and 88.5% inhibition against Brassica campestris L at the concentration of 100 mg/L. Generally speaking, this type of compounds exhibited weak herbicidal activity and might be not suitable as herbicide lead compound for further optimization.
Synthesis and characterization of [N‐methyl‐3H]loperamide
Authors: Filer Crist N. , Egan Judith A. , Nugent Richard P.
Published: April 2014

Loperamide is a piperidine butyramide mu‐opiate receptor agonist and currently employed to treat diarrhea. Because a single past report of tritiating loperamide was limited to only a very low specific activity product without technical details or extensive analysis, the synthesis of [N‐methyl‐3H]loperamide at high specific activity is now described in detail. An imine precursor was alkylated with [3H]methyl iodide to obtain a quaternary intermediate, which was then reacted with 4‐(4‐chlorophenyl)‐4‐hydroxypiperidine to afford the desired product [N‐methyl‐3H]loperamide, characterized by thin layer chromatography (TLC), HPLC, MS, UV, and proton‐decoupled tritium NMR.
Density and demography of snowshoe hares in central Colorado
Authors: Ivan Jacob S. , White Gary C. , Shenk Tanya M.
Published: April 2014

To improve understanding of snowshoe hare ecology in the Southern Rockies and enhance the ability of agency personnel to manage subalpine landscapes for snowshoe hares (Lepus americanus) and lynx (Lynx canadensis) in the region, we estimated snowshoe hare density, survival, and recruitment in west‐central Colorado, USA from July 2006–March 2009. We sampled 3 types of forest stands that purportedly provide good habitat for hares: 1) mature Engelmann spruce (Picea engelmannii)–subalpine fir (Abies lasiocarpa), 2) early seral, even‐aged lodgepole pine (Pinus contorta), and 3) mid‐seral, even‐aged lodgepole pine that had been pre‐commercially thinned. In all forest types and all seasons, snowshoe hare densities were <1.0 hares/ha. During summer, hare densities [±SE] were highest in early seral lodgepole pine (0.20 [0.01] to 0.66 [0.07] hares/ha), lowest in mid‐seral lodgepole pine (0.01 [0.04] to 0.03 [0.03] hares/ha), and intermediate in mature spruce‐fir (0.01 [0.002] to 0.26 [0.08] hares/ha). During winter, densities were more similar among the 3 stand types. Annual survival of hares was highest in mature spruce‐fir (0.14 [0.05] to 0.20 [0.07]) and similar between the 2 lodgepole stand types (0.10 [0.03] to 0.16 [0.06]). Stand attributes indicative of dense cover were positively correlated with density estimates and explained relatively more spatial process variance in hare densities than other attributes. These same attributes were not positively correlated with hare survival. Both density and survival of hares in early seral lodgepole stands were positively correlated with the extent of similar stands in the surrounding landscape. Recruitment of juvenile hares occurred during all 3 summers in early seral lodgepole stands, 2 of 3 summers in mature spruce‐fir stands, and in only 1 of 3 summers in mid‐seral lodgepole. Based on estimates of density and demography specific to each forest type, we conclude that managers should maintain mature spruce‐fir and early seral lodgepole stand types rather than thinned, mid‐seral lodgepole stands to benefit snowshoe hares (and by association lynx) in central Colorado. Given the more persistent nature of spruce‐fir compared to early seral lodgepole, and the fact that such stands cover considerably more area, mature spruce‐fir may be the most valuable forest type for snowshoe hares in the region. © 2014 The Wildlife Society.
Detection probability of least tern and piping plover chicks in a large river system
Authors: Roche Erin A. , Shaffer Terry L. , Anteau Michael J. , Sherfy Mark H. , Stucker Jennifer H. , Wiltermuth Mark T. , Dovichin Colin M.
Published: April 2014

Monitoring the abundance and stability of populations of conservation concern is often complicated by an inability to perfectly detect all members of the population. Mark‐recapture offers a flexible framework in which one may identify factors contributing to imperfect detection, while at the same time estimating demographic parameters such as abundance or survival. We individually color‐marked, recaptured, and re‐sighted 1,635 federally listed interior least tern (Sternula antillarum; endangered) chicks and 1,318 piping plover (Charadrius melodus; threatened) chicks from 2006 to 2009 at 4 study areas along the Missouri River and investigated effects of observer‐, subject‐, and site‐level covariates suspected of influencing detection. Increasing the time spent searching and crew size increased the probability of detecting both species regardless of study area and detection methods were not associated with decreased survival. However, associations between detection probability and the investigated covariates were highly variable by study area and species combinations, indicating that a universal mark‐recapture design may not be appropriate. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Incorporating environmental considerations in managing Egyptian geese on golf courses in South Africa
Authors: Mackay Beth , Little Rob M. , Amar Arjun , Hockey Phil A. R.
Published: April 2014

Egyptian geese (Alopochen aegyptiaca) occur in large numbers on golf courses in southwestern South Africa. They cause physical and financial damage to the courses and are a nuisance to golfers and golf course managers. Most control measures used to reduce the problem have been unsuccessful. We investigated the potential for environmental management options by determining which landscape features attract geese to certain areas within golf courses and cause them to avoid others. Goose vigilance levels were lower in use than in non‐use areas regardless of group size (t1 = 5.837, P ≤ 0.001, F1 = 53.877, P ≤ 0.001). This behavior suggested that geese were attracted to some areas because they perceive them to be safer. Landscape features that attracted Egyptian geese were large open patches of lawn (>1.5 ha) and proximity to water bodies (<100 m). Water bodies should not be adjacent to open foraging or loafing areas. Other modifications may include planting herbaceous vertical vegetation around water bodies and open fairways to reduce habitat openness and predator visibility. Our results suggest that the level of the goose problem at any golf course is a consequence of the intrinsic properties of that course and not influenced by the extent of the problem at nearby golf courses. © 2014 The Wildlife Society.
A mariner transposon vector adapted for mutagenesis in oral streptococci
Authors: Nilsson Martin , Christiansen Natalia , Høiby Niels , Twetman Svante , Givskov Michael , Tolker‐Nielsen Tim
Published: April 2014

This article describes the construction and characterization of a mariner‐based transposon vector designed for use in oral streptococci, but with a potential use in other Gram‐positive bacteria. The new transposon vector, termed pMN100, contains the temperature‐sensitive origin of replication repATs‐pWV01, a selectable kanamycin resistance gene, a Himar1 transposase gene regulated by a xylose‐inducible promoter, and an erythromycin resistance gene flanked by himar inverted repeats. The pMN100 plasmid was transformed into Streptococcus mutans UA159 and transposon mutagenesis was performed via a protocol established to perform high numbers of separate transpositions despite a low frequency of transposition. The distribution of transposon inserts in 30 randomly picked mutants suggested that mariner transposon mutagenesis is unbiased in S. mutans. A generated transposon mutant library containing 5000 mutants was used in a screen to identify genes involved in the production of sucrose‐dependent extracellular matrix components. Mutants with transposon inserts in genes encoding glycosyltransferases and the competence‐related secretory locus were predominantly found in this screen.
A new approach to a bridging tensor
Authors: Wang Yan‐Chao , Huang Zheng‐Ming
Published: April 2014

Bridging Model is an efficient micromechanical theory which can be used to predict the effective thermomechanical as well as strength properties of a fiber reinforced composite. The key to the Bridging Model is a bridging tensor, which was obtained on Eshelby's inclusion method [Huang and Zhou, Strength of Fibrous Composites, Vol. 53, Zhejiang University Press, Springer, Hangzhou, (2011)]. A different approach to the closed‐form expressions for the elements of a bridging tensor is presented in this work. The method is based on averaging the stress fields of a single‐fiber inclusion embedded within an infinite matrix subjected to various load conditions. By solving the bridging equations between the averaged stress components in the fiber and those in the matrix, the exact expressions for the bridging tensor elements are obtained. The Bridging Model can be established by neglecting some small quantities in the bridging tensor elements. Effective elastic moduli of a unidirectional (UD) composite are expressed as functions of a bridging tensor. Comparisons of predicted elastic properties of a total number of 18 UD composites on simplified and the exact bridging tensors are made. POLYM. COMPOS., 36:1417–1431, 2015. © 2014 Society of Plastics Engineers