bluuebunny/crossref_metadata_2025 huggingface dataset:
InAs/GaSb superlattice focal plane arrays for high-resolution thermal imaging
Authors: Rehm R. , Walther M. , Schmitz J. , Fleißner J. , Fuchs F. , Ziegler J. , Cabanski W.
Published: July 2006

The first fully operational mid-IR (3–5 μm) 256×256 IR-FPA camera system based on a type-II InAs/GaSb short-period superlattice showing an excellent noise equivalent temperature difference below 10 mK and a very uniform performance has been realized. We report on the development and fabrication of the detecor chip, i.e., epitaxy, processing technology and electro-optical characterization of fully integrated InAs/GaSb superlattice focal plane arrays. While the superlattice design employed for the first demonstrator camera yielded a quantum efficiency around 30%, a superlattice structure grown with a thicker active layer and an optimized V/III BEP ratio during growth of the InAs layers exhibits a significant increase in quantum efficiency. Quantitative responsivity measurements reveal a quantum efficiency of about 60% for InAs/GaSb superlattice focal plane arrays after implementing this design improvement.
High-performance IR detectors at SCD present and future
Authors: Nesher O. , Klipstein P.
Published: July 2006

For over 27 years, SCD has been manufacturing and developing a wide range of high performance infrared detectors, designed to operate in either the mid-wave (MWIR) or the long-wave (LWIR) atmospheric windows. These detectors have been integrated successfully into many different types of system including missile seekers, time delay integration scanning systems, hand-held cameras, missile warning systems and many others. SCD’s technology for the MWIR wavelength range is based on its well established 2D arrays of InSb photodiodes. The arrays are flip-chip bonded to SCD’s analogue or digital signal processors, all of which have been designed in-house. The 2D focal plane array (FPA) detectors have a format of 320×256 elements for a 30-μm pitch and 480×384 or 640×512 elements for a 20-μm pitch. Typical operating temperatures are around 77–85 K. Five years ago SCD began to develop a new generation of MWIR detectors based on the epitaxial growth of antimonide based compound semiconductors (ABCS). This ABCS technology allows band-gap engineering of the detection material which enables higher operating temperatures and multi-spectral detection. This year SCD presented its first prototype FPA from this program, an InAlSb based detector operating at a temperature of 100 K. By the end of this year SCD will introduce the first prototype MWIR detector with a 640×512 element format and a pitch of 15 μm. For the LWIR wavelength range SCD manufactures both linear Hg1−xCdxTe (MCT) detectors with a line of 250 elements and time delay and integration (TDI) detectors with formats of 288×4 and 480×6. Recently, SCD has demonstrated its first prototype uncooled detector which is based on VOx technology and which has a format of 384×288 elements, a pitch of 25 μm, and a typical NETD of 50 mK at F/1. In this paper, we describe the present technologies and products of SCD and the future evolution of our detectors for the MWIR and LWIR detection.
Study on the possibilities of controlling the laser output beam properties by an intracavity deformable mirror
Authors: Rabczuk G. , Sawczak M.
Published: July 2006

The possibilities of controlling the laser beam properties by a deformable mirror introduced into the laser optical cavity were studied theoretically and experimentally. The experiments were performed under conditions of an industrial high power transverse flow cw CO2 laser operating with a stable resonator of a folded configuration. A deformable bimorph mirror of a surface profile controlled by the voltage applied to the mirror electrodes is implemented to the laser system as a back cavity mirror or as a one of the inner folding mirrors. The near-and far-field characteristics of the laser beam versus the resonator configuration controlled by the changes of the focal length of the deformable mirror are discussed in the paper. The analysis reveals that the resonator with an inner deformable mirror is much more sensitive to the mirror curvature variations than the resonator in which the deformable mirror is used as a back cavity mirror. The presented results show that dynamic and controllable changes in the resonator properties result in the controlled modification and optimisation of the laser output power and spatial parameters of the laser radiation.
One dimensional model of dye-doped nematic layer for holography
Authors: Derfel G. , Buczkowska M. , Parka J.
Published: July 2006

The layer of electrically conducting nematic liquid crystal doped with photosensitive dye and confined between polyimide coated electrodes can serve as a diffraction grating. In this paper, the deformations of the nematic director field induced in such a system by external voltage were studied numerically by means of one-dimensional model. The dissociation and recombination of ions were taken into account according to weak electrolyte model. The director orientation in the deformed layers and the distributions of the electric field and of the ion concentrations were calculated for blocking and for conducting electrodes. The effective extraordinary refractive index was also determined as a function of average ion concentration.
Impressing technology of optical Bragg’s gratings on planar optical sol-gel waveguides
Authors: Pustelny T. , Zielonka I. , Tyszkiewicz C. , Karasiński P. , Pustelny B.
Published: July 2006

The aim of the presented investigations was to develop a technique of producing Bragg’s grating couplers on planar waveguides. Waveguides are obtained by means of the sol-gel technology. The introduction of a light beam into the structure of the waveguide is in the case of planar or strip optical systems always an essential technical problem, requiring simple and reproducible solutions without extending excessively the waveguide structure. The paper presents a technology of producing grating couplers by impressing the pattern of the network while forming the planar waveguide structure applying the sol-gel method. Some remarks concerning the sol-gel technology are also presented. The results of investigations on grating couplers obtained in such a way have been discussed, too.

Attention has been drawn to the possibility of using such structures in optoelectronic sensors, particularly gas sensors, including sensors of water vapour as well as toxic gases.
The Second-Year Experience: Turning Attention to the Academy's Middle Children
Authors: Gahagan Jimmie , Hunter Mary Stuart
Published: July 2006

Sophomores are the quiet ones, finishing avoided general education courses, changing their academic majors and residences, and worrying about finances. Jimmie Gahagan and Stuart Hunter describe new efforts to bring these students out of the shadows and help them succeed.
Effects of training on age estimation
Authors: Sörqvist Patrik , Eriksson Mårten
Published: July 2006

This study examined the possibility to improve accuracy of age estimates through training. Thirty‐four participants were divided into an experimental and a control group. The sessions included a pre‐test before training, six feedback or no‐feedback training tests and a post‐test after training. The experimental group performed the feedback tests and the control group the no‐feedback tests. Training was found to improve age estimation accuracy, particularly estimations of old stimuli, and training with feedback seemed to be superior to training without feedback. No difference was found between the groups at pre‐test, but at post‐test the experimental group exhibited greater accuracy in age estimation. Moreover, the experimental group increased its accuracy between the pre‐ and post‐tests. Copyright © 2006 John Wiley & Sons, Ltd.
Enhancing children's event recall after long delays
Authors: Rooy David La , Pipe Margaret‐Ellen , Murray Janice E.
Published: July 2006

The effects of context reinstatement as means of enhancing 5‐ and 6‐year‐old children's event memory in repeated interviews after a 6‐month delay were examined. Children were interviewed immediately after the event (baseline interview) and twice at a 6‐month delay, with 24 hours between interviews. The first 6‐month interview was conducted in a perfect‐context reinstatement (n = 15), imperfect‐context reinstatement (n = 16), or no‐context reinstatement (n = 15) condition. The second 6‐month interview was conducted 24 hours later with no‐context reinstatement for all children. Context reinstatement attenuated the effects of delay on recall. The accuracy of the details reported was greater in the perfect‐context compared to the imperfect‐context and no‐context conditions. Details repeated between the immediate‐baseline interview and in the first 6‐month interview were more accurate than details repeated between the first and second 6‐month interview. There was no increase in recall (hypermnesia) across the first and second 6‐month interviews in any condition. Practical implications of these findings are discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Delayed recovery of working memory following day‐case surgery
Authors: Stollery Brian
Published: July 2006

Post‐operative recovery of cognitive function is an important outcome measure following surgical anaesthesia. This study examined the influence of task complexity in 12 patients undergoing elective day‐case surgery using reaction time tasks that differed in their stimulus‐response mapping rules (compatible, incompatible, working memory). Tasks were administered at baseline, and at 1, 4 and 24 hours post‐surgery. Compared to a reference group of 18 non‐anaesthetised volunteers, the patient group showed considerable slowing one hour post‐operatively. This slowing remained at the time of discharge (4‐hours), was absent the next day, and did not vary as a function of task complexity. Only attentional lapses in the working memory task were sensitive to the recovery process and residual impairment remained the next day. The findings indicate that tasks requiring efficient access to working memory are impaired for longer than tasks simply requiring access to information passively retained in short‐term memory. Copyright © 2006 John Wiley & Sons, Ltd.
Nutritional support for patients suffering from intestinal graft‐versus‐host disease after allogeneic hematopoietic stem cell transplantation
Authors: Imataki Osamu , Nakatani Shigetoshi , Hasegawa Terumi , Kondo Miki , Ichihashi Kiyoko , Araki Mitsuko , Ishida Toshihiko , Kim Sung‐Won , Mori Shin‐ichiro , Fukuda Takahiro , Tobinai Kensei , Tanosaki Ryuji , Makimoto Atsushi , Takaue Yoichi
Published: July 2006

Background:

Patients who exhibit gastrointestinal (GI) involvement due to graft‐versus‐host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (SCT) are often recommended to withhold oral intake (NPO) to avoid further damage to the GI mucosa. However, it is possible that continuing oral intake could be beneficial in many patients compared to total parenteral nutrition (TPN).

Objective:

The primary objective of this prospective study was to evaluate whether programmed step‐ladder oral dieting (enteral nutrition; EN) is feasible and beneficial for these patients.

Methods:

A total of 18 patients who exhibited GI‐acute GVHD (stage I to III gut GVHD) after SCT received an EN dieting program, and changes in clinical and laboratory parameters were compared to those in a control cohort of 17 patients who were placed on NPO with TPN. Patients with GVHD were included prospectively and those with intestinal bleeding/obstruction, severe pancreatitis, and cytomegalovirus enterocolitis were excluded.

Results:

None of the patients in the EN group experienced significant adverse events, including exacerbation of GI symptoms. Although there was no statistically significant difference in the volume or frequency of diarrhea or the time to complete dietary recovery, parameters including body weight and serum levels of total protein and albumin tended to improve faster in the EN group.

Conclusion:

The EN diet is safely applicable to patients suffering from GI involvement by GVHD. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Comparison of perforation risk among physicians, other medical professionals and general adults with acute appendicitis in Taiwan
Authors: Deng C-Y , Huang N , Chou Y-J , Hsu Y-J , Chen L-S , Chou P
Published: July 2006

Background

This study aimed to compare the risk of appendiceal perforation among physicians, other medical professionals and general adults, when hospitalized for acute appendicitis.

Methods

National population-based data for 92 143 patients with acute appendicitis, aged 20 years or more, who underwent appendicectomy or drainage of an appendiceal abscess in Taiwan from 1996 to 2001 were analysed retrospectively. The outcome measure was appendiceal perforation. Patients were categorized as physicians (Western medical doctors), other medical professionals (such as dentists or nurses) or general adults (not medical professionals). Adjusted odds ratios and 95 per cent confidence intervals (c.i.) were estimated by multiple logistic regression.

Results

Multivariable analysis showed that appendiceal perforation was 0·67 (95 per cent c.i. 0·46 to 0·96) and 0·78 (95 per cent c.i. 0·62 to 0·99) times less likely in physicians and other medical professionals respectively than in general adults, after adjusting for patient and admitting hospital characteristics, and for calendar year.

Conclusion

The risk of perforation was significantly lower among physicians and other medical professionals than in general adults. Medical knowledge, familiarity with the healthcare system and better patient–doctor communication may have been contributory factors.
Analysis of stapling versus endoloops in appendiceal stump closure
Authors:   Swiss Association of Laparoscopic and Thoracoscopic Surgery Study Group, Beldi G , Vorburger S A , Bruegger L E , Kocher T , Inderbitzin D , Candinas D
Published: July 2006

Background

The effectiveness of various appendiceal stump closure methods has not been evaluated systematically. The aim of this study was to compare the morbidity of stump closure by stapling or use of endoloops.

Methods

A non-concurrent cohort study of prospectively acquired data was performed. The primary outcome variable was the rate of intra-abdominal surgical-site infection. Secondary outcome measures were complications, duration of intervention, hospital stay, rate of readmission to hospital and the difference in direct costs of the operation.

Results

Staples were used in 60·5 per cent and endoloops in 39·5 per cent of 6486 patients operated on for suspected appendicitis between January 1995 and December 2003. Among 4489 patients with acute appendicitis the rate of intra-abdominal surgical-site infection was 0·7 per cent in the stapler group and 1·7 per cent in the endoloop group (P = 0·004). The rate of readmission to hospital was 0·9 and 2·1 per cent respectively (P = 0·001).

Conclusion

Application of a stapler for transection and closure of the appendiceal stump in patients with acute appendicitis lowered the risk of postoperative intra-abdominal surgical-site infection and the need for readmission to hospital.
Current UK practice of thromboprophylaxis for breast surgery
Authors: Kirwan C C , McCollum C N , Bundred N J , Byrne G J
Published: July 2006

A plea for evidence
Effect of Compressed CO2 on the Critical Micelle Concentration and Aggregation Number of AOT Reverse Micelles in Isooctane
Authors: Chen Jing , Zhang Jianling , Han Buxing , Feng Xiaoying , Hou Minqiang , Li Wenjing , Zhang Zhaofu
Published: July 2006

The effect of compressed CO2 on the critical micelle concentration (cmc) and aggregation number of sodium bis‐2‐ethylhexylsulfosuccinate (AOT) reverse micelles in isooctane solution was studied by UV/Vis and florescence spectroscopy methods in the temperature range of 303.2–318.2 K and at different pressures or mole fractions of CO2 (X). The capacity of the reverse micelles to solubilize water was also determined by direct observation. The standard Gibbs free energy (Δ${G{{{\rm m}\hfill \atop {^\circ}\hfill}}}$), standard enthalpy (Δ${H{{{\rm m}\hfill \atop {^\circ}\hfill}}}$), and standard entropy (Δ${S{{{\rm m}\hfill \atop {^\circ}\hfill}}}$) for the formation of the reverse micelles were calculated by using the cmc data determined. It was discovered that the cmc versus X curve and the Δ${G{{{_{{\rm m}}}\hfill \atop {^\circ}\hfill}}}$ versus X curve for a fixed temperature have a minimum, and the aggregation number and water‐solubilization capacity of the reverse micelles reach a maximum at the X value corresponding to that minimum. These results indicate that CO2 at a suitable concentration favors the formation of and can stabilize AOT reverse micelles. A detailed thermodynamic study showed that the driving force for the formation of the reverse micelles is entropy.
Syntheses, Structural Studies, and Magnetic Properties of Divalent Cu and Co Selenites with Organic Constituents
Authors: Feng Mei‐Ling , Prosvirin Andrey V. , Mao Jiang‐Gao , Dunbar Kim R.
Published: July 2006

Six new divalent metal selenites have been synthesized by hydro‐/solvothermal methods which leads to the incorporation of the organic template as a cation or a ligand. The structure of [H2pip][Cu(SeO3)2] (1) (pip=piperazine) features 1D anionic chains of [Cu(SeO3)2]2−which are cross‐linked by the template cations through hydrogen bonds into a 2D layer. In [Cu(C3H4N2)(SeO3)] (2) the organic template is coordinated to the copper(II) ion of the inorganic Cu(SeO3) layer. The isostructural compounds [H2en][M(HSeO3)2Cl2] (en=ethylenediamine; M=Cu (3), Co (4)) contain layers of [MCl2(HSeO3)2]2−units (M=Cu, Co), which are cross‐linked by the template cations via hydrogen bonds into a 3D network. The structure of [H2en][Cu2(SeO3)2(HSeO3)]2⋅H2O (5), consists of a pillared layered architecture in which the Cu(SeO3) layers are further interconnected by bridging hydrogen selenite groups (the pillar). The compound [H2pip][Cu2(Se2O5)3] (6), which crystallizes as a 3D open framework represents the first organically templated metal diselenite. These new compounds are thermally stable up to at least 170 °C. All of the compounds exhibit fairly strong antiferromagnetic interactions. More interestingly, compounds3and4behave as a weak ferromagnets below the critical temperatures ofTc=12 and 8 K, respectively, and both of them exhibit spin‐flop phase transitions around 800±100 Oe.
Promoting culturally appropriate colorectal cancer screening through a health educator
Authors: Tu Shin‐Ping , Taylor Vicky , Yasui Yutaka , Chun Alan , Yip Mei‐Po , Acorda Elizabeth , Li Lin , Bastani Roshan
Published: July 2006

BACKGROUND.

Colorectal cancer (CRC) is a leading cause of cancer mortality in the US. Surveys reveal low CRC screening levels among Asians in the US, including Chinese Americans.

METHODS.

A randomized controlled trial was conducted with Chinese patients to evaluate a clinic‐based, culturally and linguistically appropriate intervention promoting fecal occult blood test (FOBT) screening. The multifaceted intervention included a trilingual and bicultural health educator, bilingual materials (a video, a motivational pamphlet, an informational pamphlet, and FOBT instructions), and three FOBT cards. Patients in the control arm received usual care. Our primary outcome measure was FOBT screening within 6 months after randomization. The proportion of FOBT completion in the intervention and control arms was compared by using a chi‐square test, and logistic regression analysis was performed to adjust for the effects of sociodemographic variables and prior screening history. Potential effect modifications were also tested by using logistic regression models.

RESULTS.

Our intervention had a strong effect on FOBT completion (intervention group, 69.5%; control group, 27.6%), and the adjusted odds of FOBT slightly increased to over 6‐fold greater in the intervention arm compared with the control arm. No effect modification by age, gender, language, insurance, or prior FOBT was found.

CONCLUSIONS.

The authors' multifaceted, culturally appropriate intervention significantly increased FOBT screening in a group of low‐income and less‐acculturated minority patients. Given the large effect size, future research should determine the effective core component(s) that can increase CRC screening in both the general and minority populations. Cancer 2006. © 2006 American Cancer Society.
Environmental taxation in the natural resource extraction sector: is it a good idea?
Authors: Söderholm Patrik
Published: July 2006

The purpose of this paper is to analyze the economics of taxing virgin raw materials for environmental reasons. The theoretical discussion is general in scope but empirically we focus on the case of aggregate taxation in three European countries. The motives for environmental taxation of aggregates are mixed, and not all motives find strong support in the economics literature. For instance, the conservation motive may be valid if a relevant market failure can be identified, but, in the presence of a well defined owner of the resource, resource scarcity is often not a sufficient condition for policy intervention. Under some conditions a tax levied per ton of aggregates extracted may be motivated by the presence of environmental externalities at the extraction stage. Still, such a tax provides no direct incentives to reduce the relevant externalities, since the only way of avoiding the tax is to reduce production. In this respect the UK tax appears to be particularly inefficient; it uses one policy instrument to address a number of different environmental externalities at the extraction stage (noise, dust, visual intrusion, loss of amenity and damage to biodiversity), and it is uniform across quarries although the associated externalities are likely to be highly site specific. Overall the paper concludes that taxing output or use typically represents a ‘second‐best’ policy alternative, which could be used when, for instance, the monitoring of non‐point‐source emissions and/or efficient property rights regimes are hard to implement. The fact that virgin resource taxes often address rather diffuse (not to say unimportant) environmental problems may however make them hard to promote effectively on the political arena. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Wind power policy options in finland – analysis of energy policy actors' views
Authors: Varho Vilja
Published: July 2006

Governments around the world are responding to the environmental problems caused by energy production by promoting wind power and other renewable forms of energy. Country specific political and ideological issues affect the choice of policy instruments. For example, although Finland and Sweden are already part of the same Nordic electricity market, they use different renewable energy policy instruments. The views about suitable policy instruments also vary within the Finnish energy sector. This paper is based on analysis of interviews with 25 energy sector actors that affect wind power policy in Finland. They used a number of process‐oriented and value‐based criteria to evaluate policies. Emphasis on deregulated market conditions was found to be strong, and to limit methods that are considered appropriate for supporting wind power. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Characterizing the policy instrument mixes for municipal waste in Sweden and England
Authors: Persson Åsa
Published: July 2006

In the search for effective environmental policy instruments (EPIs), the interest in combining environmental policy instruments – such as taxes and charges, tradable permit schemes, voluntary agreements, information measures, and traditional command‐and‐control regulation – in synergistic policy mixes has intensified recently (OECD, 2001a). However, there is also a need to analyse the longer term pattern in the choice of instruments for a cumulative policy mix. The aim of this paper is to examine two aspects of this pattern – diversity and coerciveness – in the field of municipal waste management in Sweden and England. Based on an inventory of instruments adopted at the national level in 1995–2005, it is concluded that the diversity has increased in both countries, although the national instrument preferences differ. Two contrasting hypotheses on coerciveness in the sequencing of instruments are then tested; the ‘minimal‐coercion’ hypothesis by Doern and Wilson (1974) and van der Doelen's (1998) ‘give‐and‐take’ strategy. It is found that Sweden has made relatively consistent choices of more coercive instruments, while a pattern of ‘give‐and‐take’ of positive and negative instruments can be discerned in the instrument mix in England. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
The variability of environmental protection expenditures between sectors in Sweden
Authors: Hammar Henrik , Löfgren Åsa
Published: July 2006

The focus of this paper is on environmental protection investments for reducing emissions to air in the pulp and paper industry and in the energy and heating industry. We use data on environmental protection investments to assess the costs for environmental protection in order to characterize the potential differences between these two industries in their ability to adapt to national policymaking. We find that the energy and heating industry invests more than the pulp and paper industry in relation to their revenues. This pattern is also true if we look at the type of environmental protection investment (i.e. clean technology or end‐of‐pipe solutions). That the pulp and paper industry is less investment intensive with regards to environmental protection is in line with what can be expected, i.e. firms in a competitive market do not seem to have the same possibility of internalizing the external cost of production in response to ‘green’ consumer demand. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Structural and Magnetic Studies of Copper(II) and Zinc(II) Coordination Complexes Containing Nitroxide Radicals as Chelating Ligands
Authors: Ito Akihiro , Nakano Yoshiaki , Urabe Masashi , Tanaka Kazuyoshi , Shiro Motoo
Published: July 2006

The mononuclear transition metal complexes [Cu(CF3SO3)212](1a), [Zn(CF3SO3)212] (1b), [Cu(CF3SO3)222]·2CH3CN (2a), and [Zn(CF3SO3)222]·2CH3CN (2b) have been preparedfrom the newly synthesized doxyl nitroxide ligands 4,4‐dimethyl‐2,2‐di(2‐pyridyl)oxazolidine‐N‐oxyl (1) and 4,4‐dimethyl‐2,2‐bis[2‐(3‐methylpyridyl)]oxazolidine‐N‐oxyl (2) and M(CF3SO3)2 (M = CuII or ZnII). These metal–nitroxide complexes have been structurally and magnetically characterized. In all complexes, the four pyridyl groups coordinate in equatorial coordination sites and the two nitroxide groups in axial coordination sites, which means that the central metal ion acquires a distorted N4O2 octahedral configuration. The variable‐temperature magnetic susceptibility data show that complexes 1b and 2b exhibit paramagnetic behavior, and hence a very weak intraligand magnetic interaction could be estimated [JNO–NO = –0.64 (1b) and 0.14 cm–1 (2b)]. The χmT values of 1a and 2a decrease continuously with decreasing temperature until they reach a nearly constant value at around 50 K, thereby indicating an intramolecular antiferromagnetic interaction between the CuII ion and the nitroxide ligands for both 1a and 2a [JCu–NO = –81.6 (1a) and–78.1 cm–1 (2b)]. These magnetic behaviors are supported by density functional theory calculations and are discussed in connection with the specific structural features. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A Poly(bicyclic dimer) and a Cyclic Tetramer: Ligand Isomerism of S2O2 Macrocycles During the Assembly of Supramolecular Silver(I) Complexes
Authors: Lee So Young , Seo Joobeom , Yoon Il , Kim Chung‐Sik , Choi Kyu Seong , Kim Jae Sang , Lee Shim Sung
Published: July 2006

Two isomeric S2O2 macrocycles (L1 and L2) with a 14‐membered cavity have been synthesised as a model system with different binding modes. Self‐assembly reactions of L1 and L2 with silver perchlorate afford the respective ligand‐directed cyclic oligomer complexes with different shapes: a poly(bicyclic dimer) (1) and a discrete cyclic tetramer (2). The formation of these supramolecular complexes is discussed in terms of conformational discrimination of two isomeric macrocycles due to ring rigidity and interdonor distances.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
A ZnII‐Based Chiral Crystalline Nanotube
Authors: Zhang Hong‐Tao , Li Yi‐Zhi , Wang Tian‐Wei , Nfor Emmanuel N. , Wang Hua‐Qin , You Xiao‐Zeng
Published: July 2006

A novel metal‐organic chiral nanotube, {[Zn(C14H10N2O4)·(H2O)4]2·H2O}n (1), with the walls consisting of homochiral triple‐stranded right‐handed (P) helices has been constructed by the reaction of acyclic ligands and zinc ions. All guest water molecules are arranged in a helical fashion inside the hydrophilic channel of the nanotube. This coordination polymer shows blue‐emitting fluorescence and displays a second harmonic generation (SHG) response in the solid state.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
An integrated microfluidic chip for DNA/RNA amplification, electrophoresis separation and on‐line optical detection
Authors: Huang Fu‐Chun , Liao Chia‐Sheng , Lee Gwo‐Bin
Published: July 2006

This study presents an integrated microfluidic chip capable of performing DNA/RNA (deoxyribonucleic acid/ribonucleic acid) amplification, electrokinetic sample injection and separation, and on‐line optical detection of nucleic acid products in an automatic mode. In the proposed device, DNA/RNA samples are first replicated using a micromachine‐based PCR module or reverse transcription PCR (RT‐PCR) module and then transported by a pneumatic micropump to a sample reservoir. The samples are subsequently driven electrokinetically into a microchannel, where they are separated electrophoretically and then detected optically by a buried optical fiber. The various modules of the integrated microfluidic chip are fabricated from cheap bio‐compatible materials, such as PDMS, polymethylmethacrylate, and soda‐lime glass. The functionality of the proposed device is demonstrated through its successful application to the DNA‐based bacterial detection of Streptococcus pneumoniae and the RNA‐based detection of Dengue‐2 virus. It is shown that the low thermal inertia of the PCR/RT‐PCR modules reduces the sample and reagent consumption and shortens the reaction time. With less human intervention, the subsequent DNA separation and detection could be performed in an automatic mode. The integrated microfluidic device proposed in this study represents a crucial contribution to the fields of molecular biology, genetic analysis, infectious disease detection, and other biomedical applications.
State estimation of networks with distributed generation
Authors: Cobelo Iñigo , Shafiu Ahmed , Jenkins Nick , Strbac Goran
Published: July 2006

The nature and control of existing distribution networks limits the amount of distributed generation that can be connected. To increase the penetration of distributed generation a distribution management system controller (DMSC) can be used. The use of a DMSC requires a state estimator algorithm that provides an estimate of the network state in real time. In this paper, a state estimation algorithm based on the methods used on transmission networks is presented. The application of these methods into distribution networks requires existing measuring systems to be supplemented with the addition of new real‐time measurements, and the use of load estimates. Copyright © 2006 John Wiley & Sons, Ltd.
A fuzzy‐tuned genetic algorithm for optimal reconfigurations of radial distribution network
Authors: Sahoo N. C. , Ranjan R. , Prasad K. , Chaturvedi A.
Published: July 2006

A large amount of power can be saved by optimal reconfiguration of radial distribution systems (RDS). Moreover, by transferring loads from the strongly loaded feeders to the lightly loaded ones, the reconfiguration of RDS can also achieve balancing of feeder loads and alleviate overload conditions. This paper presents a new approach for optimal reconfiguration of RDS based on a fuzzy‐tuned genetic algorithm by minimizing real power loss and improving loading pattern of the feeder. The proposed algorithm overcomes the combinatorial nature of the reconfiguration problem and deals with the optimization of a non‐linear, non‐continuous objective function. The main features of the proposed genetic approach for network reconfiguration are: preserving radial property of the network without islanding any load point by an elegant coding scheme and an efficient convergence characteristic attributed to tuned mutation using fuzzy logic. The proposed algorithm is tested for seven case studies on a 69‐bus RDS. Copyright © 2006 John Wiley & Sons, Ltd.
A second‐order BGK scheme for the equations of radiation hydrodynamics
Authors: Jiang Song , Sun Wenjun
Published: July 2006

We present a second‐order BGK scheme for the equations of multidimensional radiation hydrodynamics (RHE) in zero diffusion limit by using the generalized Maxwellian (Comput. Fluids 2000; 29:917–933) and the second‐order BGK scheme for the Euler equations (J. Comput. Phys. 1993; 109:53–66; Gas Kinetic Scheme for Unsteady Compressible Flow Simulations. Lecture Note Series 1998‐03. Von Kárman Institute for Fluid Dynamics, 1998). This extends a (first‐order) kinetic flux vector splitting scheme (KFVS) for RHE (Tang and Wu (2000)) to a second‐order BGK scheme. Several one‐ and two‐dimensional numerical examples demonstrate improvement of the scheme in accuracy and resolution compared with the KFVS scheme (Tang and Wu (2000)) and the first‐order BGK scheme. Copyright © 2006 John Wiley & Sons, Ltd.
A numerical simulation on diffuser‐nozzle based piezoelectric micropumps with two different numerical models
Authors: Jeong Jin , Kim Chang Nyung
Published: July 2006

This study has been conducted to compare two different numerical models for the evaluation of the performance characteristics of a diffuser‐nozzle based piezoelectric micropump. Here, the transient displacements of the membrane and the flow characteristics in the piezoelectric micropump have been closely investigated with the FSI model and the prescribed deformation model for two different frequencies. It has been found that the behaviour of the membrane computed with the FSI model is not in accordance with that with the prescribed deformation model, and that the net flow rate with the FSI model is larger than that with the prescribed deformation model. Therefore, the choice of numerical model is very important in conducting numerical analysis for piezoelectric micropumps. The results of this study can be utilized as basic data for the design and analysis of piezoelectric micropumps. Copyright © 2006 John Wiley & Sons, Ltd.
On stabilized finite element methods for the Stokes problem in the small time step limit
Authors: Bochev Pavel B. , Gunzburger Max D. , Lehoucq Richard B.
Published: July 2006

Recent studies indicate that consistently stabilized methods for unsteady incompressible flows, obtained by a method of lines approach may experience difficulty when the time step is small relative to the spatial grid size. Using as a model problem the unsteady Stokes equations, we show that the semi‐discrete pressure operator associated with such methods is not uniformly coercive. We prove that for sufficiently large (relative to the square of the spatial grid size) time steps, implicit time discretizations contribute terms that stabilize this operator. However, we also prove that if the time step is sufficiently small, then the fully discrete problem necessarily leads to unstable pressure approximations. The semi‐discrete pressure operator studied in the paper also arises in pressure‐projection methods, thereby making our results potentially useful in other settings. Copyright © 2006 John Wiley & Sons, Ltd.
Array comparative genomic hybridization reveals a very high frequency of deletions of the long arm of chromosome 6 in testicular lymphoma
Authors: Bosga‐Bouwer Anneke G. , Kok Klaas , Booman Marije , Boven Ludolf , van der Vlies Pieter , van den Berg Anke , van den Berg Eva , de Jong Bauke , Poppema Sibrand , Kluin Philip
Published: July 2006

Despite the fact that numerous studies have been performed on diffuse large B‐cell lymphoma (DLBCL), only few have concerned extranodal lymphomas occurring in the testis. We performed a cytogenetic and molecular study of 17 testicular non‐Hodgkin lymphomas, of which 14 were proven primary DLBCL of the testis. Cytogenetic analysis revealed in 8 out of 11 evaluable cases a structural abnormality of the long arm of chromosome 6, with deletion or addition of material of unknown origin, and with breakpoints spanning the region 6q12‐6q23. The cytogenetic findings were confirmed by fluorescent in situ hybridization (FISH) with a chromosome 6 painting probe. Using array based‐comparative genomic hybridization on 16 evaluable cases, including 5 cases not tested by cytogenetics or FISH, 14 (88%) showed chromosome 6q deletions. We identified two regions of minimal deletion (RMD), at 104–113 Mb (6q16.3‐q21) and 137.5–138.8 Mb (6q23.3), respectively. In one case, we observed a 2.7 Mb homozygous deletion ranging from 135.3 to 138.0 Mb that partly overlapped with the RMD at 6q23.3. Our study indicates that 6q deletions play a major pathogenetic role in DLBCL of the testis and that many of these deletions are part of unbalanced translocations. © 2006 Wiley‐Liss, Inc.
Hydrological and biogeochemical processes in a changing Amazon: results from small watershed studies and the large‐scale biosphere‐atmosphere experiment
Authors: Neill Christopher , Elsenbeer Helmut , Krusche Alex V. , Lehmann Johannes , Markewitz Daniel , de O. Figueiredo Ricardo
Published: July 2006

The Amazon Basin is the world's largest tropical forest region and one where rapid human changes to land cover have the potential to cause significant changes to hydrological and biogeochemical processes. The Large‐Scale Biosphere‐Atmosphere Experiment in Amazonia (LBA) is a multidisciplinary, multinational research program led by Brazil. The goal of LBA is to understand how the Amazon Basin functions as a regional entity in the earth system and how these functions are changing as a result of ongoing human activity. This compilation of nine papers focuses on a central LBA question in the area of nutrient dynamics and surface water chemistry—how do changes in land use alter fluxes of dissolved and particulate materials from uplands across riparian zones and down the channels of river corridors? These papers cover work conducted in small watersheds on a wide range of topics within the spirit and geographical focus area of LBA: water balance and runoff generation, nutrient transformations in riparian zones and stream channels, carbon fluxes in water moving from land to water and the influence of soils on flowpath structure and stream chemistry. Important new insights can be gained from these and other studies. Forest clearing for pastures results in a decrease in soil hydraulic conductivity that forces water into surficial flowpaths throughout most of the rainy season across wide regions of the Amazon. Riparian zones along small forest streams appear to be very effective in removing nitrate arriving from the uplands, while forest streams take up nitrate at very low rates, allowing them to travel downstream for long distances. Although substantial, the contribution of dissolved organic C (DOC) to the carbon flux from forests to streams appears to be lower than the flux of dissolved inorganic C that is subsequently outgassed as CO2. Remaining key challenges within LBA will be to synthesize existing data sets on river networks, soils, climate, land use and planned infrastructure for the Amazon to develop models capable of predicting hydrologic and biogeochemical fluxes at a variety of scales relevant to the development of strategies for sustainable management of the Amazon's remarkable forest, soil and freshwater resources. Copyright © 2006 John Wiley & Sons, Ltd.
The biogeochemistry of dissolved nitrogen, phosphorus, and organic carbon along terrestrial‐aquatic flowpaths of a montane headwater catchment in the Peruvian Amazon
Authors: Saunders Thomas J. , McClain Michael E. , Llerena Carlos A.
Published: July 2006

Dissolved nitrogen (N), phosphorus (P), and organic carbon (C) were sampled along two transects in a first‐order montane tropical (2414 m.a.s.l.) rainforest catchment of the Peruvian Amazon to investigate spatial and temporal controls on nutrient concentrations from uplands to streams. Surface and subsurface waters along transects were sampled during baseflow conditions and following rainfall events from March 2002 to March 2003. During baseflow conditions, we observed strong terrestrial controls on N, P, and dissolved organic carbon (DOC) concentrations in streams. Median NO3− concentrations were relatively constant during both dry and wet seasons in stream water (dry, 0·8 µM; wet, 1·7 µM) compared to upland soil water (dry, 15·5 µM; wet, 32·5 µM) despite significant seasonal fluctuations of NO3− in the upland, riparian, and hyporheic zones. During the dry season, concentrations of dissolved organic N (DON) also decreased markedly between the upland and the stream. Despite this decrease, DON remained the dominant component of total stream water dissolved N. Dissolved organic P (DOP) and soluble reactive P (SRP) concentrations generally followed a spatial trend inverse to that of N. Low median SRP concentrations were recorded during dry and wet seasons in the upland (dry, 0·11 µM; wet, 0·08 µM) while the highest median SRP concentrations were in stream water (dry, 0·22 µM; wet, 0·20 µM). DOP also dominated total dissolved P concentrations from the upland to the stream. Stoichiometric ratios of dissolved N and P contrasted between the upland (DON:DOP = 734, dissolved inorganic N (DIN):SRP = 166; dry season) and the stream (DON:DOP = 3, DIN:SRP = 12; dry season), indicating a clear divergence of nutrient composition between terrestrial and aquatic systems. Under baseflow conditions, strong mechanisms in the terrestrial environment and at the terrestrial–aquatic interface controlled the nutrient concentrations in the stream and buffered the seasonal fluctuations occurring in the terrestrial environment. In contrast, storm flowpaths may short‐circuit baseflow nutrient controls, thereby exporting a pulse of nutrients to the stream. Understanding the influences of storms in headwater catchments will be a valuable next step in determining the effects of changing precipitation regimes on the nutrient status of montane tropical forests and their receiving waters. Copyright © 2006 John Wiley & Sons, Ltd.
Identification of novel genes associated with astrocytoma progression using suppression subtractive hybridization and real‐time reverse transcription‐polymerase chain reaction
Authors: van den Boom Jörg , Wolter Marietta , Blaschke Britta , Knobbe Christiane B. , Reifenberger Guido
Published: July 2006

To identify novel genes involved in glioma progression we performed suppression subtractive hybridization combined with cDNA array analysis on 4 patients with primary low‐grade gliomas of World Health Organization (WHO) grade II that recurred as secondary glioblastomas (WHO grade IV). Eight genes showing differential expression between primary and recurrent tumors in 3 of the 4 patients were selected for further analysis using real‐time reverse transcription‐PCR on a series of 10 pairs of primary low‐grade and recurrent high‐grade gliomas as well as 42 astrocytic gliomas of different WHO grades. These analyses revealed that 5 genes, i.e., AMOG (ATP1B2, 17p13.1), APOD (3q26.2‐qter), DMXL1 (5q23.1) DRR1 (TU3A, 3p14.2) and PSD3 (KIAA09428/HCA67/EFA6R, 8p22), were expressed at significantly lower levels in secondary glioblastomas as compared to diffuse astrocytomas of WHO grade II. In addition, AMOG, DRR1 and PSD3 transcript levels were significantly lower in primary glioblastomas than in diffuse astrocytomas. Treatment of glioma cell lines with 5‐aza‐2′‐deoxycytidine and trichostatin A resulted in increased expression of AMOG and APOD transcripts. Sequencing of sodium bisulfite‐modified DNA demonstrated AMOG promoter hypermethylation in the glioma cell lines and 1 primary anaplastic astrocytoma with low AMOG expression. Taken together, we identified interesting novel candidate genes that likely contribute to glioma progression and provide first evidence for a role of epigenetic silencing of AMOG in malignant glioma cells. © 2006 Wiley‐Liss, Inc.
Neuropathology, tremor and electromyogram in rats exposed to manganese phosphate/sulfate mixture
Authors: Salehi Fariba , Normandin Louise , Krewski Daniel , Kennedy Greg , Philippe Suzanne , Zayed Joseph
Published: July 2006

In Canada, Methylcyclopentadienyl manganese tricarbonyl (MMT) replaced tetraethyl lead in gasoline as an antiknock agent from 1976 until 2003. The combustion of MMT leads to increased manganese (Mn) concentrations in the atmosphere, and represents one of the main sources of human exposure to Mn. The nervous system is the major target of the toxicity of Mn and Mn compounds. The purpose of this study was to investigate exposure‐response relationships for neuropathology and tremor, and the associated electromyogram (EMG), following subchronic inhalation exposure of rats to a mixture of Mn phosphate/sulfate particles. Rats were exposed 6 h per day, 5 days per week for 13 consecutive weeks at 30, 300 or 3000 µg m−3 Mn phosphate/sulfate mixture and compared with controls. Half of the rats had EMG electrodes implanted in the gastrocnemius muscle of the hind limb to assess tremor at the end of Mn exposure. Two days after the end of Mn exposure, rats were killed by exsanguination and Mn concentrations in the brain (caudate putamen, globus pallidus and frontal cortex) were determined by neutron activation analysis while neuropathology was assessed by counting neuronal cells in 2.5 mm × 2.5 mm grid areas. Increased Mn concentrations were observed in all brain sections at the highest level of exposure. The neuronal cell loss was significantly different in the globus pallidus and the caudate putamen at the highest level of exposure (3000 µg m−3). No sign of tremor was observed among the rats. In conclusion, exposure to a high level of Mn phosphate/sulfate mixture brought on neuropathological changes in a specific area of the brain; however, no sign of tremor was observed. Copyright © 2006 John Wiley & Sons, Ltd.
Treatment of chromate‐polluted groundwater in a 200 dm3 pilot bioreactor fed with hydrogen
Authors: Battaglia‐Brunet Fabienne , Touzé Solène , Michel Caroline , Ignatiadis Ioannis
Published: July 2006

Chromate is a highly soluble, toxic and carcinogenic oxyanion commonly found in groundwaters and soils. A 200 dm3 pilot bioreactor was designed to treat typical Cr(VI)‐polluted groundwater. A fixed bed column was filled with pozzolana, inoculated with a bacterial population containing the sulfate‐reducing organism Desulfomicrobium norvegicum and fed with an H2 + CO2 gas mixture. The pilot was operated under continuous feed conditions for 3 months, first with a synthetic solution and then with real polluted groundwater containing 15 mg dm−3 Cr(VI). The residence time was decreased to 7 h, while the Cr(VI) concentration in the outflow remained lower than 0.2 mg dm−3. The bacterial population did not need any organic carbon supply thanks to acetogenesis. The highest Cr(VI) reduction rate was 2.2 mg dm−3 h−1. The CO2 flow rate was regulated in order to maintain the pH in the interval 7.5–8.5. The CO2 consumption rate increased with feed flow rate and sulfate reduction activity. The process worked satisfactorily between 10 and 35 °C. Copyright © 2006 Society of Chemical Industry