bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanism of LiAlO2 decomposition during the GaN growth on (100) γ-LiAlO2
Authors: Mogilatenko A. , Neumann W. , Richter E. , Weyers M. , Velickov B. , Uecker R.
Published: July 2007

c -plane oriented GaN nucleation layers have been grown on (100) γ-LiAlO2 substrates by hydride vapor phase epitaxy. Longer recrystallization time favors the decomposition of the LiAlO2 substrate underneath the layers. The LiAlO2 decomposition at the GaN/LiAlO2 interface is accompanied by the formation of the epitaxial LiAl5O8 crystallites which are at least partly surrounded by cavities in the LiAlO2 matrix. The results suggest a mechanism that explains the spontaneous separation of thick GaN layers from LiAlO2 substrates during post-growth cooling down.
Hydrodynamics of torsional probes for atomic force microscopy in liquids
Authors: Basak Sudipta , Beyder Arthur , Spagnoli Chiara , Raman Arvind , Sachs Fredrick
Published: July 2007

Improving the force resolution of atomic force microscopy for soft samples in liquid requires soft cantilevers with reduced hydrodynamic cross section. Single and dual axis torsion levers [Beyder and Sachs, 2006] are an attractive technology. They have reduced area and reduced drift due to the symmetric support [Beyder et al., 2006] can add a second dimension using two independent axes. Here we investigate the hydrodynamics of these probes using three-dimensional transient fluid-structure interaction models with comparison to the experimental data. The computed Q factors and wet/dry resonance frequencies of different modes compare well with experimental measurements indicating that continuum viscous hydrodynamics can be used effectively to predict probe performance. The modeling further explores cross-axis hydrodynamic coupling and the influence of a nearby sample plane to provide guidance on approach algorithms and the possibilities of parametric detection.
Aligned carbon nanotubes for through-wafer interconnects
Authors: Xu Ting , Wang Zhihong , Miao Jianmin , Chen Xiaofeng , Tan Cher Ming
Published: July 2007

Through-wafer interconnects by aligned carbon nanotube for three-dimensional stack integrated chip packaging applications have been reported in this letter. Two silicon wafers are bonded together by tetra-ethyl-ortho-silicate. The top wafer (100μm thick) with patterned through-holes allows carbon nanotubes to grow vertically from the catalyst layer (Fe) on the bottom wafer. By using thermal chemical vapor deposition technique, the authors have demonstrated the capability of growing aligned carbon nanotube bundles with an average length of 140μm and a diameter of 30μm from the through holes. The resistivity of the bundles is measured to be 0.0097Ωcm by using a nanomanipulator.
Highly hydrophilic conversion on oriented TiO2 thin films synthesized by a facile spin-coating method
Authors: Miyauchi Masahiro , Tokudome Hiromasa
Published: July 2007

Single crystalline rectangular shape nanorods with an anatase or rutile TiO2 were synthesized by a soft-chemical process. These nanorods were highly dispersed in aqueous solutions and their surfaces have well-defined crystal faces, i.e., anatase (100) and rutile (110) faces. Highly oriented thin films with either an anatase and rutile phase were fabricated by facile spin coating of these colloidal solutions of nanorods without an annealing procedure. The surfaces of these films exhibited highly hydrophilic conversion under white fluorescent light bulb illumination.
Bimetallic oxide nanoparticles CoxMoyO as charge trapping layer for nonvolatile memory device applications
Authors: Liu Chien-Wei , Cheng Chin-Lung , Huang Sung-Wei , Jeng Jin-Tsong , Shiau Shiuan-Hua , Dai Bau-Tong
Published: July 2007

The reduced CoxMoyO bimetallic oxide nanoparticles (BONs) embedded in the hafnium oxynitride high-k dielectric have been developed by means of the chemical vapor deposition method. Capacitance-voltage (C-V) measurements estimate that a charge trap states density of 1.1×1012cm−2 and a flatband voltage shift of 700mV were achieved during the C-V hysteresis sweep at ±5V. Scanning electron microscopy image displays that the CoxMoyO BONs with a diameter of ∼4–20nm and a surface density of ∼1×1011cm−2 were obtained. The writing characteristics measurements illustrate that the memory effect is mainly due to the holes trapping.
Quantitative analysis of ternary vapor mixtures using a microcantilever-based electronic nose
Authors: Pinnaduwage L. A. , Zhao W. , Gehl A. C. , Allman S. L. , Shepp A. , Mahmud K. K. , Leis J. W.
Published: July 2007

The authors report the identification and quantification of the components of a ternary vapor mixture using a microcantilever-based electronic nose. An artificial neural network was used for pattern recognition. Dimethyl methyl phosphonate vapor in ppb concentrations and water and ethanol vapors in ppm concentrations were quantitatively identified either individually or in binary and ternary mixtures at varying concentrations.
In-plane Littrow lasing of broad photonic crystal waveguides
Authors: Khayam O. , Cambournac C. , Benisty H. , Ayre M. , Brenot R. , Duan G.-H. , Pernice W.
Published: July 2007

Broad photonic crystal waveguides forming open resonators are shown to support an hitherto unnoticed lasing pattern. The feedback for lasing originates in Littrow-type reflections of higher-order modes from the waveguide boundaries. The authors employ plane wave and finite-difference time-domain simulations of bulk crystal and waveguide to substantiate the concept of a distributed Littrow reflector. Experimental results are reported for a 10-μm-wide photonic crystal waveguide deeply etched into InP substrate. In-plane lasing and low modal threshold gain due to longer path lengths are the key features of this resonator.
Sign reversals in the dielectric anisotropy as functions of temperature and frequency in SmA* phase
Authors: Song Jang-Kun , Manna U. , Fukuda Atsuo , Vij J. K.
Published: July 2007

The authors observe the sign reversals in the dielectric anisotropy as functions of temperature and of frequency in SmA* phase, for the first time. The sign reversal in the dielectric anisotropy with frequency arises from the molecular relaxation process (fluctuations around the short axis), the same mechanism as for the dual frequency nematics. On the contrary, the sign reversal with temperature is due to the soft mode, which is a dominant collective relaxation process in SmA* phase and increases ϵ⊥′ sharply with decreasing temperature as the soft mode becomes more dominant close to the SmCA* to SmA* transition temperature. We find that the alignment of the cell can be controlled by applying fields of appropriate frequencies at certain temperatures. This method is so effective that we can obtain a homeotropic aligned cell that had previously been planarily aligned by applying an external alternating electric field.
Improvement of Pt Schottky contacts to n-type ZnO by KrF excimer laser irradiation
Authors: Oh Min-Suk , Hwang Dae-Kue , Lim Jae-Hong , Choi Yong-Seok , Park Seong-Ju
Published: July 2007

High quality Pt Schottky contact to n-type ZnO was formed using KrF excimer laser. A pulsed laser irradiation of n-type ZnO in O2 pressure of 0.1Mtorr, prior to Pt metal deposition, considerably improved the rectifying characteristics. The Schottky barrier heights of 0.73 and 0.85eV were obtained from the current-voltage (I-V) and capacitance-voltage (C-V) measurements, respectively. The cathodoluminescence and Auger electron spectroscopy results indicated that the improvement in rectifying characteristics can be attributed to a removal of surface carbon and hydrogen contaminants and a reduction of subsurface donorlike point defects by the KrF excimer laser irradiation.
Observation of room-temperature ferroelectricity in tetragonal strontium titanate thin films on SrTiO3 (001) substrates
Authors: Kim Y. S. , Kim D. J. , Kim T. H. , Noh T. W. , Choi J. S. , Park B. H. , Yoon J.-G.
Published: July 2007

The authors investigated the ferroelectric properties of strontium titanate (STO) thin films deposited on SrTiO3 (001) substrates with SrRuO3 electrodes. The STO layer was grown coherently on the SrTiO3 substrate without in-plane lattice relaxation, but its out-of-plane lattice constant increased with a decrease in the oxygen pressure during deposition. Using piezoresponse force microscopy and P-V measurements, the authors showed that the tetragonal STO films possess room-temperature ferroelectricity. The authors discuss the possible origins of the observed ferroelectricity.
Genome sequencing and comparative analysis of
Saccharomyces cerevisiae
strain YJM789
Authors: Wei Wu , McCusker John H. , Hyman Richard W. , Jones Ted , Ning Ye , Cao Zhiwei , Gu Zhenglong , Bruno Dan , Miranda Molly , Nguyen Michelle , Wilhelmy Julie , Komp Caridad , Tamse Raquel , Wang Xiaojing , Jia Peilin , Luedi Philippe , Oefner Peter J. , David Lior , Dietrich Fred S. , Li Yixue , Davis Ronald W. , Steinmetz Lars M.
Published: July 2007

We sequenced the genome of
Saccharomyces cerevisiae
strain YJM789, which was derived from a yeast isolated from the lung of an AIDS patient with pneumonia. The strain is used for studies of fungal infections and quantitative genetics because of its extensive phenotypic differences to the laboratory reference strain, including growth at high temperature and deadly virulence in mouse models. Here we show that the ≈12-Mb genome of YJM789 contains ≈60,000 SNPs and ≈6,000 indels with respect to the reference S288c genome, leading to protein polymorphisms with a few known cases of phenotypic changes. Several ORFs are found to be unique to YJM789, some of which might have been acquired through horizontal transfer. Localized regions of high polymorphism density are scattered over the genome, in some cases spanning multiple ORFs and in others concentrated within single genes. The sequence of YJM789 contains clues to pathogenicity and spurs the development of more powerful approaches to dissecting the genetic basis of complex hereditary traits.
Feedback activation of factor XI by thrombin does not occur in plasma
Authors: Pedicord Donna L. , Seiffert Dietmar , Blat Yuval
Published: July 2007

In this study, we tested the hypothesis that factor XI (FXI) activation occurs in plasma following activation of the extrinsic pathway by thrombin-mediated feedback activation. We used two different assays: (
i
) a direct measurement of activated FXI by ELISA and (
ii
) a functional assay that follows the activation of the coagulation cascade in the presence or absence of a FXI inhibiting antibody by monitoring thrombin activity. We failed to detect any FXI activation or functional contribution to the activation of the coagulation cascade in platelet poor or platelet-rich plasma, when activation was initiated by thrombin or tissue factor. Additionally, we found that, in the absence of a contact system inhibitor during blood draw, contact activation of FXI can mistakenly appear as thrombin- or tissue-factor-dependent activation. Thus, activation of FXI by thrombin in solution or on the surface of activated platelets does not appear to play a significant role in a plasma environment. These results call for reevaluation of the physiological role of the contact activation system in blood coagulation.
The Dynamics of Intraurban Quantile House Price Indexes
Authors: Coulson N. Edward , McMillen Daniel P.
Published: July 2007

Estimating price indexes for different quantiles shows how prices vary for homes that are in different stages of the filtering process. The paper describes a filtering model and its implication for the dynamic interaction of housing prices at these various stages. A time-series analysis of quantile price indexes for three municipalities near Chicago supports the predictions of the filtering model.
Water for All: How To Combine Public Management with Commercial Practice for the Benefit of the Poor?
Authors: Gilbert Alan
Published: July 2007

Water is critical to improving the health and welfare of the expanding urban populations of the South. Unfortunately, few cities in poor countries have managed to develop institutions able to supply the poor with water, let alone take away the waste. One city that has managed to do so is Bogota, Colombia. The results of this public company are impressive and have been achieved by adopting some elements of neo-liberal economic thought and by maintaining independence from political pressure. Recently, however, the water company's operations, and particularly its efficiency and pricing policy, have come under attack from a new left-of-centre mayor. The paper explores the legitimacy of some of the attacks and examines whether they constitute fair political debate or a means of undermining what, by the standards of the South, is an effective company.
Shadow Places: Patterns of Spatial Concentration and Incorporation of Irregular Immigrants in the Netherlands
Authors: Leerkes Arjen , Engbersen Godfried , van San Marion
Published: July 2007

In Western countries, irregular immigrants constitute a sizeable segment of the population. By combining quantitative and qualitative research methods, this article describes and explains irregular immigrants' patterns of spatial concentration and incorporation in the Netherlands. So far these spatial patterns have not been described and explained systematically, neither in the Netherlands nor elsewhere. The article shows that illegal residence is selectively embedded in the (urban) social structure in various ways. The authors argue that irregular immigrants are likely to be spatially concentrated and incorporated in similar ways in other Western countries; now and in the foreseeable future.
The Effects of Politics on Local Tax Setting: Evidence from France
Authors: Dubois Eric , Leprince Matthieu , Paty Sonia
Published: July 2007

This paper investigates the hypothesis that local politics has an impact on local taxation in the French public sector by using a cross-sectional dataset on departments in 1999. Political variables are included in a tax-setting equation to provide empirical evidence whether local governments in France adopt business taxation behaviour closer to the Leviathan government hypothesis, with higher tax rates when political competition decreases, or to the partisan government hypothesis, with differences in tax rates according to partisan variables. It is shown that the wider the seat's margin, the lower the tax rates, and that this cut is weaker in the case of a left-wing local majority than a right-wing majority. It is therefore concluded that the partisan government hypothesis is more supported by the French data than the Leviathan one, even after controlling for tax interdependencies between departments.
The Rat Mammary Gland: Morphologic Changes as an Indicator of Systemic Hormonal Perturbations Induced by Xenobiotics
Authors: Lucas Julia N. , Rudmann Daniel G. , Credille Kelly M. , Irizarry Armando R. , Peter Augustine , Snyder Paul W.
Published: July 2007

The development and morphology of the rat mammary gland are dependent upon several hormones including estrogens, androgens, progesterone, growth hormone and prolactin. In toxicology studies, treatment with xenobiotics may alter these hormones resulting in changes in the morphology of reproductive tissues such as the mammary gland. In the rat, male and female mammary glands exhibit striking morphologic differences that can be altered secondary to hormonal perturbations. Recognizing these morphologic changes can help the pathologist predict potential xenobiotic-induced perturbations in the systemic hormonal milieu. This review examines the development of the rat mammary gland and the influence of sex hormones on the morphology of the adult male and female rat mammary gland. Specific case examples from the literature and data from our laboratory highlight the dynamic nature of the rat mammary gland in response to hormonal changes.
Review of the Application of RNA Interference Technology in the Pharmaceutical Industry
Authors: Martineau Henny M. , Pyrah Ian T.
Published: July 2007

Ribonucleic acid (RNA) interference (RNAi) is a recently discovered phenomenon whereby the introduction of double stranded (ds) RNA into the cytoplasm of the cell results in the specific and efficient degradation of complementary messenger (m) RNA and, therefore, reduced protein production. It was discovered by chance during attempts to develop flowers with increased colour intensity. The specific nature of the inhibition of protein production of cells has resulted in an explosion of research to understand and exploit RNAi. The technique is now established in in vitro systems, and much work is focussed in adapting RNAi for in vivo application. The potential of the technology in understanding physiological and pathological processes is significant, while its development as a therapeutic agent holds much promise as targeted agents. This review will describe the basic biological processes that drive RNAi, indicate current areas of areas research, and forecast future areas of development.
Early Onset of Spontaneous Renal Preneoplastic and Neoplastic Lesions in Young Conventional Rats in Toxicity Studies
Authors: Lanzoni Anna , Piaia Alessandro , Everitt Jeffrey , Faustinelli Ivo , Defazio Rossella , Cavaliere Luca , Cristofori Patrizia
Published: July 2007

Although occurring in aged laboratory rodents, spontaneous renal tumour are unknown in animals younger than 18 weeks. A survey on renal preneoplastic and neoplastic lesions has been performed on Sprague-Dawley rats from general toxicology studies over the period January 2004—May 2006. Data from 2249 rats necropsied and 1206 rats (688 males and 518 females) examined microscopically from 52 studies, are reported. The age range at necropsy was between 12 and 18 weeks and all the animals were obtained from the same supplier. Three cases of tubular carcinoma, 1 tubular adenoma, and 4 cases of atypical tubular hyperplasia were observed in 5 females and 3 males from both control and treated groups from 6 studies with unrelated test compounds. In treated rats, the lesions were considered spontaneous in nature, rather than related to treatment, because of: (1) their sporadic incidence, (2) the short duration of the studies, and (3) the absence of similar lesions in other rats given the same test compound. These lesions are considered a recently occurring spontaneous finding, and the similarities with the familial renal cancer models, namely the Eker and the Nihon models, strongly suggest genetic factors as responsible for the lesions.
A Retrospective Analysis of Toxicogenomics in the Safety Assessment of Drug Candidates
Authors: Foster William R. , Chen Shen-Jue , He Aiqing , Truong Amy , Bhaskaran Vasanthi , Nelson David M. , Dambach Donna M. , Lehman-McKeeman Lois D. , Car Bruce D.
Published: July 2007

Toxicogenomics is considered a valuable tool for reducing pharmaceutical candidate attrition by facilitating earlier identification, prediction and understanding of toxicities. A retrospective evaluation of 3 years of routine transcriptional profiling in non-clinical safety studies was undertaken to assess the utility of toxicogenomics in drug safety assessment. Based on the analysis of studies with 33 compounds, marked global transcriptional changes (>4% transcripts at p < 0.01) were shown to be a robust biomarker for dosages considered to be toxic. In general, there was an inconsistent correlation between transcription and histopathology, most likely due to differences in sensitivity to focal microscopic lesions, to secondary effects, and to events that precede structural tissue changes. For 60% of toxicities investigated with multiple time-point data, transcriptional changes were observed prior to changes in traditional study endpoints. Candidate transcriptional markers of pharmacologic effects were detected in 40% of targets profiled. Mechanistic classification of toxicity was obtained for 30% of targets. Furthermore, data comparison to compendia of transcriptional changes provided assessments of the specificity of transcriptional responses. Overall, our experience suggests that toxicogenomics has contributed to a greater understanding of mechanisms of toxicity and to reducing drug attrition by empiric analysis where safety assessment combines toxicogenomic and traditional evaluations.
Animal Models of Stomach Carcinogenesis
Authors: Tsukamoto Tetsuya , Mizoshita Tsutomu , Tatematsu Masae
Published: July 2007

Although incidences of stomach cancer have decreased over the past several decades, the disease remains an important public health problem. To identify pathological and molecular biochemical mechanisms, various experimental animal models have been established in rats and mice with chemical carcinogens including N-methyl- N′-nitro- N-nitrosoguanidine (MNNG) and N-methyl-N-nitrosourea (MNU). Helicobacter pylori ( H. pylori) is one of the most important factors for human stomach disorders, including neoplasia, and the H. pylori-infected and carcinogen-treated Mongolian gerbil (MG) has proven very useful for analyses of underlying processes. The findings with this model support the hypothesis that intestinal metaplasia is important not as a precancerous lesion but rather as a paracancerous condition and that intestinalization of stomach cancer progresses with chronic inflammation. Furthermore, dose-dependent enhancing effects of salt on stomach carcinogenesis could be demonstrated in MGs treated with MNU and H. pylori modifying surface mucous gel layer. H. pylori itself only causes chronic inflammation and acts as a promoter of stomach carcinogenesis in experimental models. Based on the precise pathological diagnosis of stomach lesions such as noncancerous heterotopic proliferative glands (HPG) and adenocarcinomas, a basis for understanding mechanisms of carcinogenesis has been established on which chemoprevention can be modeled.
Social exclusion
Authors: Gray Anne
Published: July 2007

Lawless, P., Martin, R. and Hardy, S. 1998: UNEMPLOYMENT AND SOCIAL EXCLUSION: LANDSCAPES OF LABOUR INEQUALITY London: Regional Studies Association with Jessica Kingsley Press, £17.95 paper

Madanipour, A., Cars, G. and Allen, J. 1998: SOCIAL EXCLUSION IN EUROPEAN CITIES: PROCESSES, EXPERIENCES AND RESPONSES London: Regional Studies Association with Jessica Kingsley Press, £17.95 paper
Book reviews
Authors: Simon David , Billon Philippe
                      Le , Power Marcus
Published: July 2007

Communities and Reconstruction in Angola,edited by Paul Robson. Occasional Paper 1, Development Workshop, Guelph, Canada, 2001. 183pp. ISBN 0–9688768–0–1, £12.00 pbk. Reviewed by David Simon.

Angola: Front Afro‐Stalinism to Petro‐Diamond Capitalismby Tony Hodges, published by James Currey, 2001. Reviewed by Philippe Le Billon

Running Guns: The Global black market in Small ArmsbyLora Lumpe (ed.), Zed Books, London. ISBN 1 85649 873 5 (pbk) ,(2000). Reviewed by Marcus Power.

Angola's War Economy: The Role of Oil and Diamondsby Jakkie Cilliers and Christian Dietrich (eds.) (2000), Institute of Security Studies Pretoria, ISS, Pretoria. ISBN 0–620–26645–7 (pbk). Reviewed by Marcus Power.
Reviews
Authors: Malaba Luke , Cohen Robin
Published: July 2007

How long will South Africa survive?by R.W. Johnson, London: Mac‐millan, 1975, £3.95 paper

Chibaro: African Mine Labour in Southern Rhodesia 1900–1933,by Charles van Onselen (Pluto Press, London, 1976) 325pp. £7.50

Labour Perspectives on South Africa,edited by Wolfgang H. Thomas (David Philip, Cape Town, 1974) 259pp. Labour Organization and the African Worker,edited by D.B. Horner (South African Institute of Race Relations, Johannesburg, 1975) 77pp. The Durban Strikes 1973, prepared by the Institute for Industrial Education (I.I.E. — Raven Press, Durban — Johannesburg, 1974).
Reviews
Authors: Cooper David , Klein Martin A.
Published: July 2007

Beyond the Sociology of Developmentedited by Ivor Oxaal, Tony Barnett and David Booth, London, Routledge, 1975; 295pp, paperback £3.95. Sociology and Development, edited by Emmanuel De Kadt and Gavin Williams, London, Tavistock, 1974.

L'esclavage en Afrique précolonialeedited by Claude Meillassoux, François Maspero, Paris, 1975.
Reviews
Authors: Aidoo Akwasi , Munslow Barry
Published: July 2007

The Political Economy of Race and Class in South Africa,by Bernard Makhosezwe Magubane, (Monthly Review Press, New York and London, 1979), 364pp, notes, index. $18.50.

Amilcar Cabral, Unity and Struggle(Heinemann Educational Books, London 1980, pp.298, £2.25).
Reviews
Authors: Kimble Judy , Markakis John
Published: July 2007

The Ethiopian Revolutionby Fred Halliday and Maxine Molyneux, (London: Verso and New Left Books, 1981) 304 pages, £5.95 paperback.
Reviews
Authors: Cliffe Lionel , Pankhurst Donna , Lawrence Peter
Published: July 2007

Philip Raikes, Modernising Hunger: Famine, Food Surplus & Farm Policy,James Currey for Catholic Institute for International Relations, London, 1989; hb £25, pb £9.95.

Food and Agriculture Organisation of the the United Nations, African Agriculture: the Next 25 Years,
Rome, 1986; The World Bank,
Poverty and Hunger: Issues and Options for Food Security in Developing Countries,IBRD/The World Bank, Washington, D.C.1986.

Mechanization and Maize: Agriculture and the Politics of Technology Transfer in East Africaby Constance G. Anthony (New York, Columbia University Press, 1988) xiv + 178pp ISBN 0 231 06596 5 hb; Agricultural Mechanization and the Evolution of Farming Systems in East Africaby Prabu Prabhu Pingali, Yves Bigot and Hans P. Binswanger (Baltimore, Johns Hopkins (for the World Bank), 1987) viii + 216pp, ISBN 0 8018 3502 X, $14.50 hb.
Book reviews
Authors: Cohen Robin , Seddon David
Published: July 2007

Alternatives to Independence: Explorations in Post‐Colonial Relationsby Helen M. Hintjens (Aldershot: Dartmouth, 1995).

Africa's Choices: After Thirty Years of the World Bank,by Michael Barratt Brown, Penguin Books, 1995, pp. 433, £8.99 (UK).
Alcohol and drug use and related problems in the medical profession
Authors: Ball J.R.B.
Published: July 2007

Abstract: Although the physical health of doctors compares favourably with that of the general population, they have an increased prevalence of alcohol and drug problems and a higher suicide rate. Data from the U.S.A. indicate that approximately 10% of physicians become dependent on psychoactive drugs or alcohol at some time during their careers. Dynamic influences in their upbringing, pressure of work and ready access to drugs may all predispose to drug or alcohol misuse. Some strategies for handling stress are presented. Self‐prescription of psychoactive drugs is to be avoided.
The School — Influences and Approaches
Authors: Tudor R.
Published: July 2007

Abstract: In this paper some of the influences which may put young people at risk in relation to drug use are examined. Adult role models are cited as being important influences in encouraging positive behaviour in young people. The school curriculum, in which information and understanding are presented in context can be used to influence the behaviour and decisions of young people. Effective schooling can only be achieved against a background of effective parenting.
Beyond the Disease Concept of Addiction: Towards an Integration of the Moral and Scientific Perspectives
Authors: Drew L.R.H.
Published: July 2007

Abstract: This article examines governing images of drug use. It is proposed that there are preferable alternatives to the classical disease concept and its modifications (typified by the psycho‐bio‐social model of drug use). The characteristics of addictions, issues in treatment, and the elements of effective treatment approaches are described. Criticisms of the disease concept are reviewed. A new governing image must be able to accommodate the insights of science, the advances of technology, the wisdom of tradition and the reality of the moral dimension of living. The ‘way of life leading to predicaments’ model of drug use is described.
Structure‐Function Relationships in the Growing Hexa‐Coordinate Hemoglobin Sub‐Family
Authors: de Sanctis Daniele , Pesce Alessandra , Nardini Marco , Bolognesi Martino , Bocedi Alessio , Ascenzi Paolo
Published: July 2007

Hemoglobin and related heme proteins, generally referred to as 'globins', reversibly bind gaseous diatomic ligands (O2, NO, and CO) to a penta‐coordinate heme iron atom, the ligand filling the sixth coordination site. Over the last decade, several new globins have been reported to display a functionally‐relevant hexa‐coordinate heme iron atom, whose sixth coordination site is taken by an endogenous protein ligand. The reversible intramolecular hexa‐ to penta‐coordination process at the heme‐Fe atom modulates exogenous ligand binding properties of hexa‐coordinate globins. Here, we review current knowledge on hexa‐coordinate globins in terms of their structural and functional properties. IUBMB Life, 56: 643‐651, 2004
Age of acquisition predicts naming and lexical-decision performance above and beyond 22 other predictor variables: An analysis of 2,342 words
Authors: Cortese Michael J. , Khanna Maya M.
Published: July 2007

Age of acquisition (AoA) ratings were obtained and were used in hierarchical regression analyses to predict naming and lexical-decision performance for 2,342 words (from Balota, Cortese, Sergent-Marshall, Spieler, & Yap, 2004). In the analyses, AoA was included in addition to the set of predictors used by Balota et al. (2004). AoA significantly predicted latency performance on both tasks above and beyond the standard predictor set. However, AoA was more strongly related to lexical-decision performance than to naming performance. Finally, the previously reported effect of imageability on naming latencies by Balota et al. was not significant with AoA included as a factor. These results are consistent with the idea either that AoA has a semantic/lexical locus or that AoA effects emerge primarily in situations in which the input–output mapping is arbitrary.
Reconstruction of the vertebrate ancestral genome reveals dynamic genome reorganization in early vertebrates
Authors: Nakatani Yoichiro , Takeda Hiroyuki , Kohara Yuji , Morishita Shinichi
Published: July 2007

Although several vertebrate genomes have been sequenced, little is known about the genome evolution of early vertebrates and how large-scale genomic changes such as the two rounds of whole-genome duplications (2R WGD) affected evolutionary complexity and novelty in vertebrates. Reconstructing the ancestral vertebrate genome is highly nontrivial because of the difficulty in identifying traces originating from the 2R WGD. To resolve this problem, we developed a novel method capable of pinning down remains of the 2R WGD in the human and medaka fish genomes using invertebrate tunicate and sea urchin genes to define ohnologs, i.e., paralogs produced by the 2R WGD. We validated the reconstruction using the chicken genome, which was not considered in the reconstruction step, and observed that many ancestral proto-chromosomes were retained in the chicken genome and had one-to-one correspondence to chicken microchromosomes, thereby confirming the reconstructed ancestral genomes. Our reconstruction revealed a contrast between the slow karyotype evolution after the second WGD and the rapid, lineage-specific genome reorganizations that occurred in the ancestral lineages of major taxonomic groups such as teleost fishes, amphibians, reptiles, and marsupials.
Unique genes in giant viruses: Regular substitution pattern and anomalously short size
Authors: Ogata Hiroyuki , Claverie Jean-Michel
Published: July 2007

Large DNA viruses, including giant mimivirus with a 1.2-Mb genome, exhibit numerous orphan genes possessing no database homologs or genes with homologs solely in close members of the same viral family. Due to their solitary nature, the functions and evolutionary origins of those genes remain obscure. We examined sequence features and evolutionary rates of viral family-specific genes in three nucleo-cytoplasmic large DNA virus (NCLDV) lineages. First, we showed that the proportion of family-specific genes does not correlate with sequence divergence rate. Second, position-dependent nucleotide statistics were similar between family-specific genes and the remaining genes in the genome. Third, we showed that the synonymous-to-nonsynonymous substitution ratios in those viruses are at levels comparable to those estimated for vertebrate proteomes. Thus, the vast majority of family-specific genes do not exhibit an accelerated evolutionary rate, and are thus likely to specify functional polypeptides. On the other hand, these family-specific proteins exhibit several distinct properties: (1) they are shorter, (2) they include a larger fraction of predicted transmembrane proteins, and (3) they are enriched in low-complexity sequences. These results suggest that family-specific genes do not correspond to recent horizontal gene transfer. We propose that their characteristic features are the consequences of the specific evolutionary forces shaping the viral gene repertoires in the context of their parasitic lifestyles.
Solution structure of the zinc finger HIT domain in protein FON
Authors: He Fahu , Umehara Takashi , Tsuda Kengo , Inoue Makoto , Kigawa Takanori , Matsuda Takayoshi , Yabuki Takashi , Aoki Masaaki , Seki Eiko , Terada Takaho , Shirouzu Mikako , Tanaka Akiko , Sugano Sumio , Muto Yutaka , Yokoyama Shigeyuki
Published: July 2007

The zinc finger HIT domain is a sequence motif found in many proteins, including thyroid hormone receptor interacting protein 3 (TRIP‐3), which is possibly involved in maturity‐onset diabetes of the young (MODY). Novel zinc finger motifs are suggested to play important roles in gene regulation and chromatin remodeling. Here, we determined the high‐resolution solution structure of the zinc finger HIT domain in ZNHIT2 (protein FON) from Homo sapiens, by an NMR method based on 567 upper distance limits derived from NOE intensities measured in three‐dimensional NOESY spectra. The structure yielded a backbone RMSD to the mean coordinates of 0.19 Å for the structured residues 12–48. The fold consists of two consecutive antiparallel β‐sheets and two short C‐terminal helices packed against the second β‐sheet, and binds two zinc ions. Both zinc ions are coordinated tetrahedrally via a CCCC‐CCHC motif to the ligand residues of the zf‐HIT domain in an interleaved manner. The tertiary structure of the zinc finger HIT domain closely resembles the folds of the B‐box, RING finger, and PHD domains with a cross‐brace zinc coordination mode, but is distinct from them. The unique three‐dimensional structure of the zinc finger HIT domain revealed a novel zinc‐binding fold, as a new member of the treble clef domain family. On the basis of the structural data, we discuss the possible functional roles of the zinc finger HIT domain.
The solution structure of ParD, the antidote of the ParDE toxin–antitoxin module, provides the structural basis for DNA and toxin binding
Authors: Oberer Monika , Zangger Klaus , Gruber Karl , Keller Walter
Published: July 2007

ParD is the antidote of the plasmid‐encoded toxin–antitoxin (TA) system ParD–ParE. These modules rely on differential stabilities of a highly expressed but labile antidote and a stable toxin expressed from one operon. Consequently, loss of the coding plasmid results in loss of the protective antidote and poisoning of the cell. The antidote protein usually also exhibits an autoregulatory function of the operon. In this paper, we present the solution structure of ParD. The repressor activity of ParD is mediated by the N‐terminal half of the protein, which adopts a ribbon‐helix‐helix (RHH) fold. The C‐terminal half of the protein is unstructured in the absence of its cognate binding partner ParE. Based on homology with other RHH proteins, we present a model of the ParD–DNA interaction, with the antiparallel β‐strand being inserted into the major groove of DNA. The fusion of the N‐terminal DNA‐binding RHH motif to the toxin‐binding unstructured C‐terminal domain is discussed in its evolutionary context.
Domain folding and flexibility of Escherichia coli FtsZ determined by tryptophan site‐directed mutagenesis
Authors: Díaz‐Espinoza Rodrigo , Garcés Andrea P. , Arbildua José J. , Montecinos Felipe , Brunet Juan E. , Lagos Rosalba , Monasterio Octavio
Published: July 2007

FtsZ has two domains, the amino GTPase domain with a Rossmann fold, and the carboxyl domain that resembles the chorismate mutase fold. Bioinformatics analyses suggest that the interdomain interaction is stronger than the interaction of the protofilament longitudinal interfaces. Crystal B factor analysis of FtsZ and detected conformational changes suggest a connection between these domains. The unfolding/folding characteristics of each domain of FtsZ were tested by introducing tryptophans into the flexible region of the amino (F135W) and the carboxyl (F275W and I294W) domains. As a control, the mutation F40W was introduced in a more rigid part of the amino domain. These mutants showed a native‐like structure with denaturation and renaturation curves similar to wild type. However, the I294W mutant showed a strong loss of functionality, both in vivo and in vitro when compared to the other mutants. The functionality was recovered with the double mutant I294W/F275A, which showed full in vivo complementation with a slight increment of in vitro GTPase activity with respect to the single mutant. The formation of a stabilizing aromatic interaction involving a stacking between the tryptophan introduced at position 294 and phenylalanine 275 could account for these results. Folding/unfolding of these mutants induced by guanidinium chloride was compatible with a mechanism in which both domains within the protein show the same stability during FtsZ denaturation and renaturation, probably because of strong interface interactions.
Age and growth of the dusky grouper Epinephelus marginatus (Lowe 1834) in an exploited population of the western Mediterranean Sea
Authors: Reñones O. , Piñeiro C. , Mas X. , Goñi R.
Published: July 2007

The age and growth of the dusky grouper, Epinephelus marginatus, in the Balearic Islands (western Mediterranean) were studied by otolith analysis from a sample of 358 specimens ranging in total length (LT) from 6·6 to 105·6 cm. The specimens came from commercial artisanal and recreational spear fisheries between 1999 and 2003. Otoliths grew asymmetrically throughout the range of LT studied, showing a clear pattern of alternating translucent and opaque bands. Marginal increment analysis of specimens up to 8 years‐old indicated that a single opaque band was formed each year during spring and summer. Whole otoliths allowed ageing specimens up to 10 years old, but above that age whole otoliths yielded lower age estimates than sectioned otoliths. The maximum estimated age was 61 years, which significantly extends the estimated life span of the species from a maximum of 36 years in a previous study. The von Bertalanffy growth parameters were estimated as L∞= 95·5 cm LT, K= 0·087 and TO=−1·12. The study revealed differences in mean LT at age and age structure between the shallow‐ and deep‐water samples which may be attributed to different fishing pressure and environmental conditions.
Burst and coast use, swimming performance and metabolism of Atlantic cod Gadus morhua in sub‐lethal hypoxic conditions
Authors: Dutil J.‐D. , Sylvestre E.‐L. , Gamache L. , Larocque R. , Guderley H.
Published: July 2007

Prolonged swimming capacity (critical swimming speed, Ucrit, protocol) and metabolism were measured for 14 Atlantic cod Gadus morhua exposed to seven oxygen levels within the non‐lethal range normally encountered in the Gulf of St Lawrence (35 to 100% saturation). Burst‐and‐coast swimming was triggered earlier (at lower speeds) in hypoxia, and burst‐and‐coast movements were more frequent in hypoxia than in normoxia at low speeds. Furthermore, the metabolic scope beyond the metabolic rate at which Atlantic cod resorted to burst‐and‐coast movements decreased gradually as ambient oxygen concentration dropped. Overall, fewer burst‐and‐coast movements were observed in hypoxia while the distance swum in burst‐and‐coast mode remained c. 1% of the total distance swam in all tests. Oxygen availability had no effect on the rate of increase in metabolic rate with increasing velocity <50 cm s−1, but limited swimming performances and metabolic rate at higher speeds. The prevailing low oxygen tensions on the bottom in the deep channels may impair the swimming capacity of Atlantic cod in the estuary and northern Gulf of St Lawrence.
Annual cycle of stored spermatozoa within the ovaries of Helicolenus dactylopterus dactylopterus (Teleostei, Scorpaenidae)
Authors: Vila S. , Munoz M. , Sabat M. , Casadevall M.
Published: July 2007

The aim of this work was to analyse the ultrastructure of storage crypts and stored spermatozoa, and to describe changes during the annual reproductive cycle of the bluemouth Helicolenus dactylopterus dactylopterus, which has internal fertilization and a zygoparous mode of reproduction. Spermatozoa had elongated heads and long midpieces, two characteristics which are thought to be fairly advanced and correlated with internal fertilization, as is the case of the bluemouth. A remarkable spermatozoon feature was the retention of a significant quantity of cytoplasm around the head, a condition that appeared to be related to nourishment during the long storage period, up to 10 months in the intraovarian crystal structures of the female. Male sex cells’ protection against the female immune system was ensured by junctional complexes between the crypt cells composed of tight junctions and desmosomes.
Epidural anaesthesia for Caesarean section in a patient with Devic's Syndrome
Authors: Gunaydin B. , Akcali D. , Alkan M.
Published: July 2007

The anaesthetic management of a 29‐year‐old paraplegic woman suffering from Devic's Syndrome scheduled to undergo Caesarean section under epidural anaesthesia is presented. The case is discussed with particular reference to the risk of autonomic hyperreflexia.
A comparison of shallow Danish and Canadian lakes and implications of climate change
Authors: JACKSON LELAND J. , LAURIDSEN TORBEN L. , SØNDERGAARD M. , JEPPESEN ERIK
Published: July 2007

1. Winter temperatures differ markedly on the Canadian prairies compared with Denmark. Between 1 January 1998 and 31 December 2002, average weekly and monthly temperatures did not drop below 0 °C in the vicinity of Silkeborg, Denmark. Over this same time, weekly average temperatures near Calgary, Alberta, Canada, often dropped below −10 °C for 3–5 weeks and the average monthly temperature was below 0 °C for 2–4 months. Accordingly, winter ice conditions in shallow lakes in Canada and Denmark differed considerably.

2. To assess the implications of winter climate for lake biotic structure and function we compared a number of variables that describe the chemistry and biology of shallow Canadian and Danish lakes that had been chosen to have similar morphometries.

3. The Danish lakes had a fourfold higher ratio of chlorophyll‐a: total phosphorus (TP). Zooplankton : phytoplankton carbon was related to TP and fish abundance in Danish lakes but not in Canadian lakes. There was no significant difference in the ratio log total zooplankton biomass : log TP and the Canadian lakes had a significantly higher proportion of cladocerans that were Daphnia. These differences correspond well with the fact that the Danish lakes have more abundant and diverse fish communities than the Canadian lakes.

4. Our results suggest that severe Canadian winters lead to anoxia under ice and more depauperate fish communities, and stronger zooplankton control on phytoplankton in shallow prairie lakes compared with shallow Danish lakes. If climate change leads to warmer winters and a shorter duration of ice cover, we predict that shallow Canadian prairie lakes will experience increased survivorship of planktivores and stronger control of zooplankton. This, in turn, might decrease zooplankton control on phytoplankton, leading to ‘greener’ lakes on the Canadian prairies.
Periphyton responds differentially to nutrients recycled in dissolved or faecal pellet form by the snail grazer Theodoxus fluviatilis
Authors: LIESS ANTONIA , HAGLUND ANN‐LOUISE
Published: July 2007

1. We aimed to separate the effects of grazers on periphyton via grazing from that of nutrient recycling from their faecal pellets.

2. We set up three different experimental treatments (snails/no snails/faecal pellets) and sampled over 16 days. The ‘snail’ treatment contained a low density (snail biomass c. 14 g−2) of the gastropod grazer Theodoxus fluviatilis and the ‘faecal pellet’ treatment received the same amount of faecal pellets as were produced in the ‘snail’ treatment. Whereas the ‘faecal pellet’ treatment provided extra nutrients to periphyton from the faeces, the ‘snail’ treatment provided nutrients in the form of both faeces and in excreta. There was also direct grazing on periphyton in the ‘snail’ treatment. The ‘no snail’ was not grazed and received no nutrients in faeces or excreta.

3. We measured periphyton C, N and P content, chlorophyll‐a (chl‐a), primary production, bacterial biomass, bacterial production and bacterial respiratory activity. In the water column we measured dissolved inorganic N and soluble reactive P.

4. Snails increased the amount of dissolved inorganic N in the water. On day 16, the periphyton N : P ratio in the ‘faecal pellet’ treatment was lower, and periphyton P content was higher, than in the other two treatments. N : P ratios decreased over time in the ‘faecal pellet’ treatment. Primary and bacterial production were positively correlated in all treatments.

5. Algal chl‐a and primary production of periphyton per unit area and periphyton chl‐a : C ratios increased over the 16 day in the ‘snail’ treatment, and thus excretion of dissolved N by snails had a stronger positive effect on the periphyton community than N and P in faecal pellets.

6. Our data show that excretion and egestion can have different effects on periphyton, probably because of the higher proportion of dissolved N in excreta and the higher proportion of P recycled in faecal pellets. The relative effect of nutrients recycled in egesta or in excretions, probably depends on the form of nutrient limitation of the periphyton. Further, the different components of the periphyton matrix could react differently to the different forms of nutrient recycling.

7. We conclude that direct grazing effects are less important than nutrient effects when nutrients are limiting and grazing pressure is low. Further, the spatial separation of different grazing effects can lead to differences in periphyton production and nutrient stoichiometry. This might be an explanation for the patchiness of periphyton in nature.
Self‐care ability in a group of elderly Swedish people: a phenomenological study
Authors: Rnt Olle Söderhamn
Published: July 2007

Self‐care ability in a group of elderly Swedish people: a phenomenological study The aims of this study were to describe self‐care ability in a group of Swedish elderly and to elucidate the meaning of actualizing this self‐care ability into self‐care activity. Two different phenomenological methods were applied in the analyses of 11 self‐reports written by home dwelling elderly in the community. The eidetic structure of self‐care ability was twofold; it entailed, first, being present to the opportunity to act on certain perceived influences on the body and, second, alone or with support from somebody else to be able to bring about a change in attitude towards one's personal lifestyle or life situation. The meaning of actualizing this ability was interpreted as self‐realization or self‐transcendence.