bluuebunny/crossref_metadata_2025 huggingface dataset:
ZebraBAN: a heterogeneous high‐performance energy efficient wireless body sensor network
Authors: Lu Xiyu , Chen Xinlei , Li Yong , Jin Depeng , Zeng Lieguang , Rashvand Habib F.
Published: August 2013

Recently, there are much research on wireless body sensor network (WBSN) as the growing demands of pervasive health and personal entertainment. Supporting high‐speed data transmission becomes a challenge in development of WBSN in medical and entertainment applications. In this study, the authors present ZebraBAN, a high‐speed low‐power WBSN based on single‐carrier ultra‐wideband (SC‐UWB) and IEEE 802.15.4. The heterogeneous network combines the strengths of SC‐UWB and IEEE 802.15.4 technologies while offsetting their weakness. Like SC‐UWB, the system achieves medium to high data rate and reduces radiation and power consumption at a low cost. Like IEEE 802.15.4, ZebraBAN achieves low data rate and low latency under low contention. In ZebraBAN, the authors introduce the idea of control plane and data plane for controlling multiple PHYs and MACs according to energy and data rate balance. Experimental results based on the prototype system are presented to evaluated the network performance. The result demonstrates that high reliability transmission for every sensor data stream within 4 m around the person, with a low‐power consumption for fabricated application specific integrated circuits (ASIC) about 8.2 mW when it works on transmitting one channel video. The network has a peak capacity of 100 Mbps that could support multiple sensor nodes, including four channel video stream and multiple low‐speed sensor datas.
Electro‐oxidation and simultaneous determination of amlodipine and atorvastatin in commercial tablets using carbon nanotube modified electrode
Authors: Mohammadi Ali , Moghaddam Abdolmajid Bayandori , Eilkhanizadeh Kordestan , Alikhani Elham , Mozaffari Shahla , Yavari Tahereh
Published: August 2013

Amlodipine besylate and atorvastatin calcium have been determined by the simultaneous voltammetric method at a multi‐walled carbon nanotubes:graphite (MWCNTs:G) paste electrode. In comparison with a glassy carbon electrode, the prepared electrode showed an increase in the peak current because of the high electroactive surface area and excellent electronic conductivity of MWCNTs. The dependence of currents and potentials on pH were investigated for these components at the surface of the MWCNTs:G paste electrode. Differential pulse voltammetry was applied as a sensitive technique for simultaneous determination of the drugs in commercial tablets. By anodic differential pulse voltammetry, the calibration plot was linear in the range of 2.5–100 µg/ml with standard deviation between 2.7–7.1 and 1.8–8.3% for amlodipine and atorvastatin, respectively. The detection limit was 1 µg/ml at the prepared electrode in the buffered solution pH 6.
Normal spinel CoCr2O4 and CoCr2O4/TiO2 nanocomposite as novel photocatalysts, for degradation of dyes
Authors: Shojaei Abdollah Fallah , Tabari Atefeh Roshan , Loghmani Mohammad Hassan
Published: August 2013

For the first time, CoCr2O4/TiO2 nanocomposite as a novel photocatalyst with different TiO2 contents have been prepared by the sol–gel method. The techniques of X‐ray diffraction (XRD), scanning electron microscopy and transmission electron microscopy (TEM) have been employed to characterise the synthesised nanocatalysts. The XRD and TEM results indicated that CoCr2O4 has a cubic normal spinel structure and the particle size of CoCr2O4 is about 30 nm. As the first report, degradation of methylene blue and methyl orange is performed by CoCr2O4 and CoCr2O4/TiO2 nanocomposite under ultraviolet irradiation. The results showed that the rate of degradation of dyes with CoCr2O4/TiO2 is much higher compared with that of CoCr2O4 and TiO2. The photocatalytic activities were carried out under varying parameters such as irradiation time, the pH of the solution, the catalyst amount and substrate concentration.
Bioreduction of chloroaurate ions using fruit extract Punica granatum (Pomegranate) for synthesis of highly stable gold nanoparticles and assessment of its antibacterial activity
Authors: Basavegowda Nagaraj , Sobczak‐Kupiec Agnieszka , Fenn Rebecca Isacc , Dinakar Salman
Published: August 2013

The design, synthesis and characterisation of biologically synthesised nanomaterials have become an area of significant interest. Presented is a report on the extracellular synthesis of gold nanoparticles using Punica granatum (Pomegranate) fruit extract as the reducing agent to synthesise Au nanoparticles. On treating aqueous chloroauric acid solutions with P. granatum fruit extract, rapid reduction of the chloroaurate ions is observed, leading to the formation of highly stable gold nanoparticles in solution. These nanoparticles showed an absorption peak at 536 nm in the UV–vis spectrum corresponding to the plasmon resonance of gold nanoparticles. Scanning electron microscopy analysis of the gold nanoparticles indicated that they ranged in size from 10 to 50 nm. The Fourier transform infrared spectroscopy spectrum confirmed the presence of main groups occurred in natural plant extract from P. granatum. The synthesised gold nanoparticles were active against Streptobacillus sp. and Escherichia coli.
Nanographene device fabrication using atomic force microscope
Authors: Ahmad Muneer , Seo Yongho , Choi Young Jin
Published: August 2013

A report is presented on the local anodic oxidation of graphene film prepared by chemical vapour deposition using contact mode atomic force microscopy. Raman spectroscopy was used to check the uniformity and thickness of large area graphene film. Various kinds of patterns such as lines, ribbons and further, more complex structures, such as hexagons, two‐terminal bar‐like devices, were written by varying the tip voltage from −6 to −12 V and the tip speed from 60 to 200 nm/s. It was found that one can easily write any kind of patterns by just manipulating the tip voltage and tip speed instead of concentrating on other factors such as controlled humidity conditions, applied force on the tip and tip current. Also, it is confirmed that with an increase in tip voltage and by slowing the tip movement during lithography, one can write very narrow and sharp patterns which are important factors for the fabrication of graphene‐based electronic devices.
New Group-Contribution Approach to Thermochemical Properties of Organic Compounds: Hydrocarbons and Oxygen-Containing Compounds
Authors: Verevkin S. P. , Emel'yanenko V. N. , Diky V. , Muzny C. D. , Chirico R. D. , Frenkel M.
Published: August 2013

A new group-contribution approach involving systematic corrections for 1,4-non-bonded carbon-carbon and carbon-oxygen interactions has been proposed. Limits of the applicability of the method, associated with the highly branched structures, were established. Experimental data for enthalpies of formation in the liquid phase, enthalpies of vaporization, and enthalpies of formation in the gas phase for alkanes, alkenes, alkynes, alkylbenzenes, alkanols, ethers, ketones and aldehydes, carboxylic acids, esters, and carbonates were collected and critically evaluated through dynamic data evaluation as implemented in the NIST ThermoData Engine. An automatic procedure for molecular structure “decomposition” was developed, and algorithms for the assessment of expanded uncertainties for the predicted property values were implemented. The combination of these software tools allows for ongoing improvements of the group-contribution parameter set as new experimental data become available. Fifty-two group-contribution parameters and their variances were evaluated for the proposed schema. Based on comparison of critically evaluated and predicted data for all classes of compounds studied, the performance of the new group formulation and associated parameters is superior to that originally suggested by Benson and the update by Cohen without an increase in the number of required parameters.
A brightness exceeding simulated Langmuir limit
Authors: Nakasuji Mamoru
Published: August 2013

When an excitation of the first lens determines a beam is parallel beam, a brightness that is 100 times higher than Langmuir limit is measured experimentally, where Langmuir limits are estimated using a simulated axial cathode current density which is simulated based on a measured emission current. The measured brightness is comparable to Langmuir limit, when the lens excitation is such that an image position is slightly shorter than a lens position. Previously measured values of brightness for cathode apical radii of curvature 20, 60, 120, 240, and 480 μm were 8.7, 5.3, 3.3, 2.4, and 3.9 times higher than their corresponding Langmuir limits, respectively, in this experiment, the lens excitation was such that the lens and the image positions were 180 mm and 400 mm, respectively. From these measured brightness for three different lens excitation conditions, it is concluded that the brightness depends on the first lens excitation. For the electron gun operated in a space charge limited condition, some of the electrons emitted from the cathode are returned to the cathode without having crossed a virtual cathode. Therefore, method that assumes a Langmuir limit defining method using a Maxwellian distribution of electron velocities may need to be revised. For the condition in which the values of the exceeding the Langmuir limit are measured, the simulated trajectories of electrons that are emitted from the cathode do not cross the optical axis at the crossover, thus the law of sines may not be valid for high brightness electron beam systems.
Origins of ion irradiation-induced Ga nanoparticle motion on GaAs surfaces
Authors: Kang M. , Wu J. H. , Sofferman D. L. , Beskin I. , Chen H. Y. , Thornton K. , Goldman R. S.
Published: August 2013

We have examined the origins of ion irradiation-induced nanoparticle (NP) motion. Focused-ion-beam irradiation of GaAs surfaces induces random walks of Ga NPs, which are biased in the direction opposite to that of ion beam scanning. Although the instantaneous NP velocities are constant, the NP drift velocities are dependent on the off-normal irradiation angle, likely due to a difference in surface non-stoichiometry induced by the irradiation angle dependence of the sputtering yield. It is hypothesized that the random walks are initiated by ion irradiation-induced thermal fluctuations, with biasing driven by anisotropic mass transport.
Real-time, auto-focusing digital holographic microscope using graphics processors
Authors: Doğar Mert , İlhan Hazar A. , Özcan Meriç
Published: August 2013

The most significant advantage of holographic imaging is that one does not need to do focusing alignment for the scene or objects while capturing their images. To focus on a particular object recorded in a digital hologram, a post-processing on the recorded image must be performed. This post-processing, so called the reconstruction, is essentially the calculation of wave propagation in free space. If the object's optical distance to the recording plane is not known a priori, focusing methods are used to estimate this distance. However, these operations can be quite time consuming as the hologram sizes increase. When there is a time constraint on these procedures and the image resolution is high, traditional central processing units (CPUs) can no longer satisfy the desired reconstruction speeds. Then, especially for real-time operations, additional hardware accelerators are required for reconstructing high resolution holograms. To this extend, today's commercial graphic cards offer a viable solution, as the holograms can be reconstructed tens of times faster with a graphics processing unit than with the state-of-the-art CPUs. Here we present an auto-focusing megapixel-resolution digital holographic microscope (DHM) that uses a graphics processing unit (GPU) as the calculation engine. The computational power of the GPU allows the DHM to work in real-time such that the reconstruction distance is estimated unsupervised, and the post-processing of the holograms are made completely transparent to the user. We compare DHM with GPU and CPU and present experimental results showing a maximum of 70 focused reconstructions per second (frps) with 1024 × 1024 pixel holograms.
Why is Boris algorithm so good?
Authors: Qin Hong , Zhang Shuangxi , Xiao Jianyuan , Liu Jian , Sun Yajuan , Tang William M.
Published: August 2013

Due to its excellent long term accuracy, the Boris algorithm is the de facto standard for advancing a charged particle. Despite its popularity, up to now there has been no convincing explanation why the Boris algorithm has this advantageous feature. In this paper, we provide an answer to this question. We show that the Boris algorithm conserves phase space volume, even though it is not symplectic. The global bound on energy error typically associated with symplectic algorithms still holds for the Boris algorithm, making it an effective algorithm for the multi-scale dynamics of plasmas.
Nuclear dynamics of decaying states: A semiclassical approach
Authors: Sisourat N.
Published: August 2013

A semiclassical method is proposed for carrying out molecular fragmentation simulations following electronic decay processes. The nuclear motion is treated classically during and after the electronic decay while a quantum mechanical description is used for the electron dynamics. The method is compared with full quantum results for benchmark examples. Good agreement is achieved. Such a method should be very useful for studying large systems for which a quantum description is not feasible.
Solar-blind AlxGa1−xN/AlN/SiC photodiodes with a polarization-induced electron filter
Authors: Rodak L. E. , Sampath A. V. , Gallinat C. S. , Chen Y. , Zhou Q. , Campbell J. C. , Shen H. , Wraback M.
Published: August 2013

Heterogeneous n-III-nitride/i-p silicon carbide (SiC) photodetectors have been demonstrated that enable the tailoring of the spectral response in the solar blind region below 280 nm. The negative polarization induced charge at the aluminum gallium nitride (AlxGa1−xN)/aluminum nitride (AlN) interface in conjunction with the positive polarization charge at the AlN/SiC interface creates a large barrier to carrier transport across the interface that results in the selective collection of electrons photoexcited to the Γ and L valleys of SiC while blocking the transport of electrons generated in the M valley. In addition, the AlxGa1−xN alloys act as transparent windows that enhance the collection of carriers generated by high energy photons in the fully depleted SiC absorption regions. These two factors combine to create a peak external quantum efficiency of 76% at 242 nm, along with a strong suppression of the long-wavelength response from 260 nm to 380 nm.
Hydrogen (deuterium) vibron frequency as a pressure comparison gauge at multi-Mbar pressures
Authors: Howie Ross T. , Gregoryanz Eugene , Goncharov Alexander F.
Published: August 2013

The Raman spectra of compressed hydrogen (deuterium) have been measured in the multi-Mbar pressure range in the diamond anvil cell using the position of the stressed first-order Raman diamond edge (DE) to estimate pressure. We find that the Raman spectra are very consistent in repeated experiments for the critical frequencies of the hydrogen (deuterium) bands at the phase transition pressure-temperature (P-T) points. However, measurements of pressure determined from the DE in different experiments vary substantially with virtually identical Raman spectra of H2 (D2), giving in some cases a pressure variation as high as 20 GPa. These variations do not only depend on sample and sample chamber geometry but also on the P-T path taken, thus making the DE pressure determination uncertain. Therefore, we propose in experiments on hydrogen (deuterium) to use the Raman frequency of the intramolecular vibration (vibron) of H2(D2) as a pressure sensor. By comparing the vibron frequencies and considering the geometrical changes of the sample chamber caused by very high pressures, we propose an alternative explanation to the recent claims of a transformation to a metallic liquid state of hydrogen (deuterium).
Reversible optical memory based on single-component phototropic liquid crystal
Authors: Sobolewska A. , Bartkiewicz S. , Mysliwiec J.
Published: August 2013

The authors report fully reversible holographic recording of the diffraction grating realized using the phenomenon of the photochemical phase transition of the single- component phototropic liquid crystal. The grating was formed as a result of the isotropic-to-nematic phase transition. The writing, reading, and erasure of the holograms were performed only by means of the light. A typical degenerate two-wave mixing experiment was used for the grating recording combined with a polarized optical microscope enabling the observation in the real time. The dynamics of the process was investigated as a function of the writing laser beams intensity from 30 mW/cm2 to 200 mW/cm2.
Doping-free silicon thin film solar cells using a vanadium pentoxide window layer and a LiF/Al back electrode
Authors: Jung Hyung Hwan , Kwon Jung-Dae , Lee Sunghun , Su Kim Chang , Nam Kee-Seok , Jeong Yongsoo , Chung Kwun-Bum , Yoon Ryu Seung , Ocak Tülay , Eray Aynur , Kim Dong-Ho , Park Sung-Gyu
Published: August 2013

This work describes the preparation of a doped layer-free hydrogenated amorphous silicon (a-Si:H) thin film solar cell consisting of a vanadium pentoxide (V2O5-x) window layer, an intrinsic a-Si:H absorber layer, and a lithium fluoride (LiF)/aluminum (Al) back electrode. The large difference between the work functions of the V2O5-x layer and the LiF/Al electrode permitted photogenerated carriers in the i-a-Si:H absorber layer to be effectively separated and collected. The effects of the V2O5-x layer thickness and the oxidation states on the photovoltaic performance were investigated in detail. X-ray photoelectron spectroscopy analysis confirmed that the major species of the sputtered V2O5-x thin films were V5+ and V4+. Optimization of the V2O5-x window layer yielded a power conversion efficiency of 7.04%, which was comparable to the power conversion efficiency of a typical a-Si:H solar cell (7.09%).
Mixture of [60] and [70]PCBM giving morphological stability in organic solar cells
Authors: Santo Yoshihide , Jeon Il , Sheng Yeo Kee , Nakagawa Takafumi , Matsuo Yutaka
Published: August 2013

Mix-PCBM, comprising [6,6]-phenyl-C61-butyric acid methyl ester (PC60BM) and [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM), is a promising acceptor material for use in organic solar cells with higher device stability and cost performance. The inverted photovoltaic device using poly(3-hexylthiophene) (P3HT) and mix-PCBM exhibited a power conversion efficiency (PCE) of 3.34% (open-circuit voltage = 0.63 V, short-circuit current density = 8.55 mA/cm2, and fill factor = 0.60), slightly higher than that using P3HT and PC60BM (PCE = 3.27%). More importantly, the mix-PCBM device was more stable to heating at 150 °C than the PC60BM device, due to little morphological change, which was characterized by atomic force microscope and light absorption measurements.
Electron barrier study of mid-wave infrared interband cascade photodetectors
Authors: Tian Z.-B. , Schuler-Sandy T. , Krishna S.
Published: August 2013

In this paper, we report our experimental investigation on the influence of electron barrier (eB) in mid-infrared interband cascade photodetectors. Even though earlier theoretical projection indicates that an eB with 2-pairs GaSb/AlSb quantum wells (QWs) is sufficient to block electrons direct tunneling between stages, our experimental results show that a thicker (with 6-pairs of GaSb/AlSb QWs) electron barrier could significantly reduce the device dark current, with little influence on the optical performance. The 5-stage devices have demonstrated a dark current density of 1.10 × 10−7 A/cm2 (at −5 mV) and a Johnson-limited D* of 1.81 × 1011 cmHz1/2/W (at 3.8 μm) at 150 K, respectively.
Nucleation-controlled gold-induced-crystallization for selective formation of Ge(100) and (111) on insulator at low-temperature (∼250 °C)
Authors: Park Jong-Hyeok , Suzuki Tsuneharu , Kurosawa Masashi , Miyao Masanobu , Sadoh Taizoh
Published: August 2013

Selective formation of Ge(100) and (111) on amorphous-insulator at low-temperatures (∼250 °C) is realized through gold-induced-crystallization using a-Ge/Au/SiO2 stacked-structures by combining interface-energy-modulation of substrates. Introduction of thin-Al2O3 layers (∼7 nm thickness) at a-Ge/Au interfaces enables large-grain (≥20 μm) Ge(111) formation, which is speculated to be due to suppression of random bulk-nucleation and domination of (111)-oriented interface-nucleation on SiO2. To examine this speculation, Al2O3-covered substrates are employed. This results in formation of Ge(100), due to energetically favorable (100)-oriented interface-nucleation on Al2O3. Consequently, large-grain (≥20 μm) Ge(100) and (111) are achieved on amorphous-insulators at 250 °C. This technique is very useful to realize flexible-electronics.
Wh-Questions in Colloquial Singapore English
Authors: Sato Yosuke
Published: August 2013

This paper discusses supplementary roles played by Bazaar Malay and Baba Malay in the genesis of wh-questions in Colloquial Singapore English (CSE). CSE has three options for wh-questions: (a) full wh-movement, (b) partial wh-movement, and (c) wh-in-situ, just like Bazaar Malay and Baba Malay. Whereas options (a) and (c) arose under pressure from English and Chinese, option (b) apparently challenges the Sinitic substrate hypothesis on CSE for two reasons. Firstly, neither Cantonese nor Hokkien possesses partial wh-movement. Secondly, it is mysterious how the apparent Malayic pattern could have entered the pool of CSE features within the predominantly Sinitic contact environment. This paper proposes that partial wh-movement was added onto the CSE grammar as an evolutionary ‘adaptive’ trait from Malay which survived selective Sinitic pressures due to congruence between Malay and Chinese. Both Cantonese and Hokkien possess a wh-topicalization structure, which is sufficiently similar to the partial structure in Malay. As a result, the former served as the template for Chinese speakers to analyze the latter as a congruence structure in the emerging variety. This result supports the recent view that typological congruence between Sinitic and Malay must be taken into account in any discussion of the origin/development of CSE grammar.
The Modernisation Process Through the Perceptions of Work–Family in Spain and Great Britain
Authors: Gaspar Marta Ortega
Published: August 2013

This paper explores the work–family conflict as perceived by working parents in two European countries, Spain and Great Britain (GB). Using data from the International Social Survey Programme, ISSP 2002, we examine the factors that explain the high level of conflict in the two countries, for both men and women. Whereas sex, age and having children at home impact the level of conflict in Spain, education level as a proxy for class is more relevant in the GB. The contrasting perceptions of the work–family conflict in the two countries may be taken as indicators of each country's stage in what has been called the ‘modernization process’. This study seeks to understand the relationship between the level of ‘modernization’ and the perception of a high level of conflict in the attempt to reconcile the work–family conflict, focusing on the process of ‘individualization’ on the one hand and measurement of ‘the perception of the level of conflict by sex’ on the other.1 The study argues that the difference between these high levels of conflict is explained by variables that refer to ascribed status in Spain (a pro-traditional model) but to acquired status in GB (a non-interventionist model) indicated by the influence of education level as a variable resulting from a person's effort.
Use of Lethal Short-Term Chlorine Exposures to Limit Release of Nonnative Freshwater Organisms
Authors: Ingersoll Christopher G , Brunson Eric L , Hardesty Doug K , Hughes Jamie P , King Brittany L , Phillips Catherine T
Published: August 2013

Fish hatcheries and other types of aquatic facilities are potential sources for the introduction of nonnative species of fish or aquatic invertebrates into watersheds. Chlorine has been suggested for use to kill organisms that might be released from the effluent of a facility. While acute LC50s (concentrations lethal to 50% of organisms exposed for up to 96 h) for chlorine are available for some species, short-term LC100s for chlorine have not been determined. The objective of this study is to establish concentrations of chlorine that are lethal to 100% of organisms after brief (1-, 5-, or 15-min) exposures. A total of 22 species were exposed to total residual chlorine concentrations (TRC) of 1, 10, or 25 mg TRC/L for 1, 5, or 15 min under static conditions followed by a 24-h postexposure recovery period in water without the addition of chlorine. Concentrations of chlorine resulting in 100% lethality of organisms were established for all of the species tested except for four species of mollusks or for a beetle. Exposures for 5 to 15 min to 10–25 mg TRC/L were the lowest combined time–chlorine treatments under which all of the fish tested and the other invertebrates tested (17 species) exhibited 100% lethality by the end of the initial chlorine exposures or after the 24-h recovery period.
Effect of maternal nitrogen and drought stress on seed dormancy and germinability of Amaranthus retroflexus
Authors: Karimmojeni Hassan , Bazrafshan Amir Hossein , Majidi Mohammad Mehdi , Torabian Shahram , Rashidi Behzad
Published: August 2013

Amaranthus retroflexus L. is an importunate annual weed in many cropping systems of different countries. The main aim of this study was to investigate the effects of maternal nitrogen and drought stress on the seed dormancy and germinability of A. retroflexus. Field experiment was carried out in a factorial based on randomized complete block design, with four potential levels of soil water (–2, −6, −8 and −10 bar) and three levels of nitrogen (0, 100 and 200 kg/ha). The germination characteristics of the seeds were measured at three different times (1 month, 6 months and 1 year after harvesting). Results showed that drought stress had positive effects on breaking of A. retroflexus seed dormancy until 6 months after seed harvesting. Seeds that were developed under severe water stress exhibited the highest germination percentage and germination rate. The results obtained from this study revealed that application of 100 kg/ha nitrogen during seed development increases germinability of A. retroflexus, whereas application of 200 kg/ha nitrogen induced seed dormancy. Furthermore, 100 kg/ha nitrogen application in the field along with 200 ppm gibberellic‐acid treatment during seed after‐ripening showed the highest germination percentage and germination rate for seeds after 6 months harvesting. Results also indicated that after‐ripening significantly increased seed germination and germination rate of A. retroflexus. These findings indicate that long‐term management of the soil seed bank in this species requires more stringent control due to the changes in germination timing, as detected in this study.
Isolation of sublineage I Nitrospira by a novel cultivation strategy
Authors: Fujitani Hirotsugu , Ushiki Norisuke , Tsuneda Satoshi , Aoi Yoshiteru
Published: August 2013

Nitrification is an important process in the biogeochemical nitrogen cycle and is widely exploited in biological wastewater treatment. Recently, Nitrospira has been recognized as the numerically dominant nitrite‐oxidizing bacterial genus and is primarily responsible for the second step of aerobic nitrification. Nevertheless, the physiological properties of Nitrospira remain poorly understood because the organisms are difficult to isolate and culture. Here, we report a novel cultivation strategy for obtaining members of the Nitrospira sublineage I in pure culture. The method combines: (i) selective enrichment of Nitrospira using a continuous feeding reactor and (ii) purification followed by sub‐cultivation via a cell sorting system by focusing on the unique characteristics of Nitrospira forming spherical micro‐colonies. This strategy is potentially applicable to other uncultured or unisolated Nitrospira and could accelerate the physiological and biochemical understandings of this important group of organisms.
Developmental cycle and host interaction of Rhabdochlamydia porcellionis, an intracellular parasite of terrestrial isopods
Authors: Sixt Barbara S. , Kostanjšek Rok , Mustedanagic Azra , Toenshoff Elena R. , Horn Matthias
Published: August 2013

Environmental chlamydiae are a diverse group of obligate intracellular bacteria related to well‐known pathogens of humans. To date, only very little is known about chlamydial species infecting arthropods. In this study, we used cocultivation with insect cells for recovery and maintenance of Rhabdochlamydia porcellionis, a parasite of the crustacean host Porcellio scaber. In vitro, the infection cycle of R. porcellionis was completed within 7 days, resulting in the release of infectious particles by host cell lysis. Lack of apoptosis induction during the entire course of infection, combined with a reduced sensitivity of infected cultures to experimentally induced programmed cell death, indicates that R. porcellionis like its human pathogenic relatives counteracts this host defence mechanism. Interestingly, the rod‐shaped variant of R. porcellionis, proposed to represent their mature infective stage, was not detected in cell culture, suggesting that its development may require prolonged maturation or may be triggered by specific conditions encountered only in the animal host. This first cell culture‐based system for the cultivation and investigation of an arthropod‐associated chlamydial species will help to better understand the biology of a so far neglected group of chlamydiae and its recently suggested potential to cause disease in humans.
Effects of Various Heat Treatments on Phenolic Profiles and Antioxidant Activities of Pleurotus eryngii Extracts
Authors: Li Siqian , Shah Nagendra P.
Published: August 2013

Free (FP) and bound phenolics (BP) were extracted from freeze dried (FD), oven dried (OD), as well as boiling treated (BT) Pleurotus eryngii samples. Free, bound, total phenolics were quantified using Folin–Ciocalteau assay. Qualitative and quantitative analysis of phenolic compounds were carried out using high‐performance liquid chromatography (HPLC) coupled with diode array detector (DAD), and a total of 8 phenolic compounds were detected. Free phenolic contents followed the order: Freeze‐dried free phenolics (FDFP) > Oven‐dried free phenolics (ODFP) > Boiling‐treated free phenolics (BTFP), and ranged from 95.42 (BTFP) to 442.50 (ODPF) μg gallic acid equivalents (GAE)/g dry weight (DW). Bound and total phenolic contents followed the order: FD > OD > BT, and ranged from 218.33 (BTBP) to 774.17 (FDBP) and 313.75 (BT total phenolics) to 1090.42 (FD total phenolics) μg GAE/g DW. Bound phenolics contributed 49.76% (OD), 69.59% (BT), and 71% (FD) of the total phenolic contents. All free and bound phenolic extracts were investigated for their antioxidant activities by 3 different assays, 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging activity, reducing power, and superoxide anion radical scavenging activity. FDFP showed strongest DPPH radical scavenging activity (IC50 at 32.61 μg/mL), ODFP showed strongest reducing power (IC50 at 26.31 μg/mL), and BTBP showed strongest superoxide anion radical scavenging activity (IC50 at 14.07 μg/mL).
Syntrophic growth with direct interspecies electron transfer as the primary mechanism for energy exchange
Authors: Shrestha Pravin Malla , Rotaru Amelia‐Elena , Aklujkar Muktak , Liu Fanghua , Shrestha Minita , Summers Zarath M. , Malvankar Nikhil , Flores Dan Carlo , Lovley Derek R.
Published: August 2013

Direct interspecies electron transfer (DIET) through biological electrical connections is an alternative to interspecies H2 transfer as a mechanism for electron exchange in syntrophic cultures. However, it has not previously been determined whether electrons received via DIET yield energy to support cell growth. In order to investigate this, co‐cultures of Geobacter metallireducens, which can transfer electrons to wild‐type G. sulfurreducens via DIET, were established with a citrate synthase‐deficient G. sulfurreducens strain that can receive electrons for respiration through DIET only. In a medium with ethanol as the electron donor and fumarate as the electron acceptor, co‐cultures with the citrate synthase‐deficient G. sulfurreducens strain metabolized ethanol as fast as co‐cultures with wild‐type, but the acetate that G. metallireducens generated from ethanol oxidation accumulated. The lack of acetate metabolism resulted in less fumarate reduction and lower cell abundance of G. sulfurreducens. RNAseq analysis of transcript abundance was consistent with a lack of acetate metabolism in G. sulfurreducens and revealed gene expression levels for the uptake hydrogenase, formate dehydrogenase, the pilus‐associated c‐type cytochrome OmcS and pili consistent with electron transfer via DIET. These results suggest that electrons transferred via DIET can serve as the sole energy source to support anaerobic respiration.
Arterial Peculiarities of the Thoracolumbar Spinal Cord in Rabbit
Authors: Mazensky D. , Danko J. , Petrovova E. , Mechirova E. , Prokes M.
Published: August 2013

The aim of this study was to investigate the arterial blood supply of the thoracolumbar spinal cord in rabbit. The study was carried out on twenty adult New Zealand white rabbits. Ten rabbits were used in the corrosion technique and ten rabbits in the dissection technique. After the killing, the vascular network was perfused with saline. Batson's corrosion casting kit no. 17 © was used as a casting medium. After polymerisation of the medium, in ten rabbits the maceration was carried out in KOH solution, and in ten other rabbits, formaldehyde was injected by the dissection technique into the vertebral canal. We found high variability of segmental arteries supplying blood to the spinal cord. There are 12 intercostal arteries and 1 costo‐abdominal artery. Dorsal branches arising from the dorsal surface of the aorta thoracica were found as follows: in 70% of the cases, 9 pairs were present; in 20% of the cases 8 pairs; and in 10% of the cases 10 pairs. The paired arteriae lumbales were present in 6 pairs in 90% of the cases and in 5 pairs in 10% of the cases. On the dorsal surface of spinal cord, we found two irregular longitudinal arteries in 70% of the cases, no longitudinal arteries in 20% of the cases and three irregular longitudinal arteries in 10% of the cases receiving dorsal branches of rami spinales. Among the dorsal branches observed in the thoracic region, 60.5% were left‐sided, 39.5% right‐sided and in the lumbar region, 52.5% were left‐sided and 47.5% right‐sided.
Effects of Reference Analgesics and Psychoactive Drugs on the Noxious Heat Threshold of Mice Measured by an Increasing‐Temperature Water Bath
Authors: Boros Melinda , Benkó Rita , Bölcskei Kata , Szolcsányi János , Barthó Loránd , Pethő Gábor
Published: August 2013

The study aimed at validating an increasing‐temperature water bath suitable for determining the noxious heat threshold for use in mice. The noxious heat threshold was determined by immersing the tail of the gently held awake mouse into a water container whose temperature was near‐linearly increased at a rate of 24°C/min. until the animal withdrew its tail, that is, heating attained the noxious threshold. The effects of standard analgesic, neuroleptic and anxiolytic drugs were investigated in a parallel way on both the noxious heat threshold and the psychomotor activity assessed by the open field test. Morphine, diclofenac and metamizol (dipyrone) elevated the heat threshold of mice with minimum effective doses of 6, 30 and 1000 mg/kg i.p., respectively. These doses of morphine and diclofenac failed to induce any remarkable effect on psychomotor activity in the open field test while that of metamizol exerted a profound inhibition. The anxiolytic diazepam and the neuroleptic droperidol at doses evoking a mild and moderate, respectively, psychomotor inhibition failed to alter the heat threshold. Combination of a subliminal dose of morphine (regarding both antinociceptive and psychomotor inhibitory action) with diclofenac, metamizol, diazepam or droperidol at doses also subliminal regarding the thermal antinociceptive effect elevated the noxious heat threshold without major additional effects in the open field test. It is concluded that the increasing‐temperature water bath is suitable for studying the thermal antinociceptive effects of morphine and diclofenac as well as the morphine‐sparing action of diclofenac, metamizol, droperidol and diazepam. Behavioural testing is recommended when testing analgesics.
Using Joint Utilities of the Times to Response and Toxicity to Adaptively Optimize Schedule–Dose Regimes
Authors: Thall Peter F. , Nguyen Hoang Q. , Braun Thomas M. , Qazilbash Muzaffar H.
Published: August 2013

A Bayesian two‐stage phase I–II design is proposed for optimizing administration schedule and dose of an experimental agent based on the times to response and toxicity in the case where schedules are non‐nested and qualitatively different. Sequentially adaptive decisions are based on the joint utility of the two event times. A utility function is constructed by partitioning the two‐dimensional positive real quadrant of possible event time pairs into rectangles, eliciting a numerical utility for each rectangle, and fitting a smooth parametric function to the elicited values. We assume that each event time follows a gamma distribution with shape and scale parameters both modeled as functions of schedule and dose. A copula is assumed to obtain a bivariate distribution. To ensure an ethical trial, adaptive safety and efficacy acceptability conditions are imposed on the (schedule, dose) regimes. In stage 1 of the design, patients are randomized fairly among schedules and, within each schedule, a dose is chosen using a hybrid algorithm that either maximizes posterior mean utility or randomizes among acceptable doses. In stage 2, fair randomization among schedules is replaced by the hybrid algorithm. A modified version of this algorithm is used for nested schedules. Extensions of the model and utility function to accommodate death or discontinuation of follow up are described. The method is illustrated by an autologous stem cell transplantation trial in multiple myeloma, including a simulation study.
PHOG: Photometric and geometric functions for textured shape retrieval
Authors: Biasotti S. , Cerri A. , Giorgi D. , Spagnuolo M.
Published: August 2013

In this paper we target the problem of textured 3D object retrieval. As a first contribution, we show how to include photometric information in the persistence homology setting, also proposing a novel theoretical result about multidimensional persistence spaces. As a second contribution, we introduce a generalization of the integral geodesic distance which fuses shape and color properties. Finally, we adopt a purely geometric description based on the selection of geometric functions that are mutually independent. The photometric, hybrid and geometric descriptions are combined into a signature, whose performance is tested on a benchmark dataset.
An Operator Approach to Tangent Vector Field Processing
Authors: Azencot Omri , Ben‐Chen Mirela , Chazal Frédéric , Ovsjanikov Maks
Published: August 2013

In this paper, we introduce a novel coordinate‐free method for manipulating and analyzing vector fields on discrete surfaces. Unlike the commonly used representations of a vector field as an assignment of vectors to the faces of the mesh, or as real values on edges, we argue that vector fields can also be naturally viewed as operators whose domain and range are functions defined on the mesh. Although this point of view is common in differential geometry it has so far not been adopted in geometry processing applications. We recall the theoretical properties of vector fields represented as operators, and show that composition of vector fields with other functional operators is natural in this setup. This leads to the characterization of vector field properties through commutativity with other operators such as the Laplace‐Beltrami and symmetry operators, as well as to a straight‐forward definition of differential properties such as the Lie derivative. Finally, we demonstrate a range of applications, such as Killing vector field design, symmetric vector field estimation and joint design on multiple surfaces.
Fitting Polynomial Volumes to Surface Meshes with Voronoï Squared Distance Minimization
Authors: Paillé Gilles‐Philippe , Poulin Pierre , Lévy Bruno
Published: August 2013

We propose a method for mapping polynomial volumes. Given a closed surface and an initial template volume grid, our method deforms the template grid by fitting its boundary to the input surface while minimizing a volume distortion criterion. The result is a point‐to‐point map distorting linear cells into curved ones. Our method is based on several extensions of Voronoi Squared Distance Minimization (VSDM) combined with a higher‐order finite element formulation of the deformation energy. This allows us to globally optimize the mapping without prior parameterization. The anisotropic VSDM formulation allows for sharp and semi‐sharp features to be implicitly preserved without tagging. We use a hierarchical finite element function basis that selectively adapts to the geometric details. This makes both the method more efficient and the representation more compact. We apply our method to geometric modeling applications in computer‐aided design and computer graphics, including mixed‐element meshing, mesh optimization, subdivision volume fitting, and shell meshing.
Consistent Volumetric Discretizations Inside Self‐Intersecting Surfaces
Authors: Sacht Leonardo , Jacobson Alec , Panozzo Daniele , Schüller Christian , Sorkine‐Hornung Olga
Published: August 2013

Decades of research have culminated in a robust geometry processing pipeline for surfaces. Most steps in this pipeline, like deformation, smoothing, subdivision and decimation, may create self‐intersections. Volumetric processing of solid shapes then becomes difficult, because obtaining a correct volumetric discretization is impossible: existing tet‐meshing methods require watertight input. We propose an algorithm that produces a tetrahedral mesh that overlaps itself consistently with the self‐intersections in the input surface. This enables volumetric processing on self‐intersecting models. We leverage conformalized mean‐curvature flow, which removes self‐intersections, and define an intrinsically similar reverse flow, which prevents them. We tetrahedralize the resulting surface and map the mesh inside the original surface. We demonstrate the effectiveness of our method with applications to automatic skinning weight computation, physically based simulation and geodesic distance computation.
Animation‐Aware Quadrangulation
Authors: Marcias Giorgio , Pietroni Nico , Panozzo Daniele , Puppo Enrico , Sorkine‐Hornung Olga
Published: August 2013

Geometric meshes that model animated characters must be designed while taking into account the deformations that the shape will undergo during animation. We analyze an input sequence of meshes with point‐to‐point correspondence, and we automatically produce a quadrangular mesh that fits well the input animation. We first analyze the local deformation that the surface undergoes at each point, and we initialize a cross field that remains as aligned as possible to the principal directions of deformation throughout the sequence. We then smooth this cross field based on an energy that uses a weighted combination of the initial field and the local amount of stretch. Finally, we compute a field‐aligned quadrangulation with an off‐the‐shelf method. Our technique is fast and very simple to implement, and it significantly improves the quality of the output quad mesh and its suitability for character animation, compared to creating the quad mesh based on a single pose. We present experimental results and comparisons with a state‐of‐the‐art quadrangulation method, on both sequences from 3D scanning and synthetic sequences obtained by a rough animation of a triangulated model.
Noise‐Adaptive Shape Reconstruction from Raw Point Sets
Authors: Giraudot Simon , Cohen‐Steiner David , Alliez Pierre
Published: August 2013

We propose a noise‐adaptive shape reconstruction method specialized to smooth, closed shapes. Our algorithm takes as input a defect‐laden point set with variable noise and outliers, and comprises three main steps. First, we compute a novel noise‐adaptive distance function to the inferred shape, which relies on the assumption that the inferred shape is a smooth submanifold of known dimension. Second, we estimate the sign and confidence of the function at a set of seed points, through minimizing a quadratic energy expressed on the edges of a uniform random graph. Third, we compute a signed implicit function through a random walker approach with soft constraints chosen as the most confident seed points computed in previous step.
Clinical assessment of delayed gastric emptying and diabetic complications using gastric emptying scintigraphy: Involvement of vascular disorder
Authors: Kotani Kohei , Kawabe Joji , Kawamura Etsushi , Kawano Naoya , Emoto Masanori , Yoshida Atsushi , Higashiyama Shigeaki , Morioka Tomoaki , Inaba Masaaki , Shiomi Susumu
Published: August 2013

Aim

Delayed gastric emptying, including gastroparesis, is a common complication in diabetes mellitus. The association between delayed gastric emptying and overall diabetic complications remains to be studied in detail. We analysed this association.

Methods

We performed gastric emptying scintigraphy of 99mTc‐diethylenetriaminepentaacetic acid in 34 patients with diabetes to measure the gastric emptying half‐times (T1/2) of the whole stomach (WS), proximal stomach (PS) and distal stomach (DS). We assessed T1/2, diabetic‐related factors and complications.

Results

The prevalence of autonomic neuropathy was higher in the group with delayed T1/2 of the WS than in the normal group. Analysis of intima‐media thickness (IMT) and ankle brachial pressure index (ABI), which are risk indicators for vascular disorder, showed that IMT of the carotid bulb was greater in the group with delayed T1/2 of the WS than in the normal group (2·41 mm [1·50–2·81] versus 1·40 mm [0·81–2·08], P = 0·015). T1/2 of the WS correlated positively with IMT of the carotid bulb (r = 0·391, P = 0·027) and negatively with ABI (r = −0·389, P = 0·028). These correlations were mainly attributed to PS and were the same in patients without autonomic neuropathy. In seven of nine patients who received scintigraphy again after diabetic treatment, glycosylated haemoglobin (HbA1c) levels decreased and T1/2 of the WS shortened compared with before treatment.

Conclusion

Vascular disorder, among other cofactors such as autonomic neuropathy, could be involved in the pathophysiology of delayed gastric emptying. Medium‐ to long‐term glycaemic control was associated with gastric emptying.