bluuebunny/crossref_metadata_2025 huggingface dataset:
EPR study of Ni distribution in LaNiy Co1–yO3 solid solutions (0 ≤ y ≤ 0.25)
Authors: Ivanova S. , Zhecheva E. , Stoyanova R.
Published: June 2008

The distribution of Ni in LaNiy Co1–y O3 solid solutions was examined by means of EPR spectroscopy. For the assignment of the EPR signals, La1–x Srx CoO3 oxides were used as reference for Co3+–Co4+ magnetic clusters. For the oxides heated at 600 °C, the EPR spectra of LaNiy Co1–y O3 consist of a signal due to magnetic Ni clusters, while the oxides prepared at 700 °C display an EPR signal due to ferromagnetic coupled Co3+ and Co4+ impurity ions that do not form magnetic clusters. LaNiy Co1–y O3 samples prepared at T > 700 °C are EPR “silent”. The effect of the preparation method and the preparation temperature on the formation of Ni clusters is discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and characterization of Fe3Si/SiO2 structures for spintronics
Authors: Mantovan R. , Georgieva M. , Fanciulli M. , Goikhman A. , Barantcev N. , Lebedinskii Yu. , Zenkevich A.
Published: June 2008

The Fe3Si thin film is a good candidate as ferromagnetic electrode in spintronics devices due to its high spin polarization and high Curie temperature. The use of Fe3Si in contact with a thin SiO2 barrier can have various applications in practical devices, such as magnetic tunnel junctions. We report on the synthesis of Fe3Si/SiO2 structures, in one vacuum cycle, by pulsed laser deposition and glow‐discharge plasma oxidation followed by vacuum annealing. The structural and morphological characterization of the Fe3Si/SiO2 stacks is performed by in‐situ X‐ray photoelectron spectroscopy and with atomic force microscopy. Using a 57Fe tracer layer, conversion electron Mössbauer spectroscopy is performed at the Fe3Si/SiO2 interface, proving the formation of a ferromagnetic phase with no paramagnetic inclusions. Our experimental results indicate that the Fe3Si/SiO2 stack is a promising system for application in spintronics devices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Paramagnetic and ferromagnetic resonance studies on dilute magnetic semiconductors based on GaN
Authors: Kammermeier T. , Dhar S. , Ney V. , Manuel E. , Ney A. , Ploog K. H. , Lo F.‐Y. , Melnikov A. , Wieck A. D.
Published: June 2008

Magnetic resonance studies were preformed on the dilute magnetic semiconductor Gd:GaN. In samples grown by molecular beam epitaxy resonances were observed at temperatures below 50 K. The temperature dependence of the resonance field and the line width suggest a ferromagnetic origin. No similar signals were found in Gd implanted samples even for a Gd concentration ten times higher. At temperatures close to 5 K additional signals were observed near g = 2 in these samples. They are superimposed by a strong substrate signal which is observable in all samples and is attributed to nitrogen donors on sites of different symmetry in the SiC substrate crystal. Different possible explanations of our findings are discussed with special regard to a model suggesting magnetically polarized spheres of influence. By means of magnetic resonance we can not corroborate ferromagnetism at room temperature in Gd:GaN as suggested by SQUID data. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chemoselective Nanowire Fuses: Chemically Induced Cleavage and Electrical Detection of Carbon Nanofiber Bridges
Authors: Li Bo , Shang Lu , Marcus Matthew S. , Clare Tami Lasseter , Perkins Edward , Hamers Robert J.
Published: June 2008

A new type of nanoscale bioswitch based on the electrical detection of chemically induced cleavage of chemical bonds, which bind individual nanowires across a pair of electrodes is demonstrated. Carbon nanofibers are manipulated using dielectrophoresis to form single‐nanowire bridges across microelectrode junctions, and are anchored through a biomolecular interaction. Once in place, chemically induced cleavage of a recognition site along the bonds linking the nanowire to the electrodes allows the nanowire to be easily removed by a flow of fluid; this removal can be detected in real time via changes in the AC electrical response. This form of sensing is inherently digital in nature as the removal of a single nanowire produces a sudden decrease in the current between electrodes and is essentially a chemoselective fuse. These results suggest that this sensing principle could be a general method for digital chemical and/or biological sensing using individual nanowires.
Low‐Dimensional, Hinged Bar‐code Metal Oxide Layers and Free‐Standing, Ordered Organic Nanostructures from Turbostratic Vanadium Oxide
Authors: O'Dwyer Colm , Lavayen Vladimir , Fuenzalida David , Lozano Harold , Ana Maria A. Santa , Benavente Eglantina , González Guillermo , Sotomayor Torres Clivia M.
Published: June 2008

Both low‐dimensional bar‐coded metal oxide layers, which exhibit molecular hinging, and free‐standing organic nanostructures can be obtained from unique nanofibers of vanadium oxide (VOx). The nanofibers are successfully synthesized by a simple chemical route using an ethanolic solution of vanadium pentoxide xerogel and dodecanethiol resulting in a double bilayered laminar turbostratic structure. The formation of vanadium oxide nanofibers is observed after hydrothermal treatment of the thiol‐intercalated xerogel, resulting in typical lengths in the range 2–6 µm and widths of about 50–500 nm. We observe concomitant hinging of the flexible nanofiber lamina at periodic hinge points in the final product on both the nanoscale and molecular level. Bar‐coded nanofibers comprise alternating segments of organic–inorganic (thiols–VOx) material and are amenable to segmented, localized metal nanoparticle docking. Under certain conditions free‐standing bilayered organic nanostructures are realized.
Gossypol analysis in cottonseed oil by HPLC
Authors: Chamkasem N.
Published: June 2008

Gossypol in cottonseed oil was selectively separated by the extraction of cottonseed oil with a hexane and N,N dimethyl formamide:water (2∶1, v/v) solvent mixture. After filtration, the extract was injected into the HPLC with the elution time less than 15 min. The spectrophotometric method showed 2 to 5 times higher values of gossypol content in different types of glanded cottonseed oil than did the HPLC method. This is probably due to the gossypol derivatives and coloring interferences reacting with p‐anisidine to develop color and increasing the absorbance reading, whereas gossypol was separated and detected in the HPLC method.
Factors affecting refining losses in rice (Oryza sativa L.) bran oil
Authors: Mishra Arvind , Gopalakrishna A. G. , Prabhakar J. V.
Published: June 2008

Components of rice bran oil have been assessed for their effect on refining losses. Rice bran oil used in the study had the following (percent) analysis: free fatty acids, 6.8; phosphatides, 1.25; wax, 2.85; monoglycerides, 1.67; diglycerides, 4.84, and oryzanol, 1.85; the rest (80.74) was mostly triglycerides. The phosphatides and mono‐ and diglycerides had no noticeable effect on refining losses at levels of up to 2% in the oil. Waxes and oryzanol increased the refining losses substantially. In model experiments where these were incorporated into peanut oil individually and in combination, the wax at as low a level as 1% increased the refining losses by about 80% more than control and the refining losses increased with concentration of wax. Oryzanol had a similar effect. When wax and oryzanol were present together in the oil, the effect was synergistic—the refining losses were higher than the sum of their individual effects. Phosphatides, mono‐ and diglycerides tended to reduce the adverse effect of wax and oryzanol. The main components responsible for higher than normal refining losses in rice bran oil have been identified as wax and oryzanol.
Oleochemical surfactants and lubricants in the textile industry
Authors: Proffitt Thomas J. , Thomas Patterson H.
Published: June 2008

This paper reviews the published literature on the uses of oleochemical surfactants and lubricants in the textile industry with a dual emphasis on textile technology and effects that oleochemicals can have on that technology. Oleochemical derivatives are used in the textile industry as surfactants, emulsifiers, wetting agents, antistatic agents, softeners, antimicrobial agents, water and oil repellents, antisoil agents, lubricants, cohesive agents and dyeing assistants. The relationship between the amount of fatty acid derivatives consumed in textile operations and global fiber production is discussed. Small amounts of oleochemicals acting at interfaces are invaluable in their effects on textiles. Oleochemical surfactant chemical and physical properties of importance in textile operations are described, and the relationships between certain properties of oleochemicals and their performance on textile fibers are reviewed. The basic principles and technology of spin finishes and textile processing aids are discussed. The effects of oleochemical surfactants in dyeing and as finishing agents for textile fibers are described briefly. The conclusion presents the prognosis for the future of oleochemicals in the textile industry.
THE CORRESPONDENCE OF THOMAS HOBBES: SOME NEW ITEMS
Authors: MALCOLM NOEL , TOLONEN MIKKO
Published: June 2008

This article presents the full text of a hitherto unpublished letter to Hobbes, and provides details of three other items from his correspondence which have not survived. The unpublished letter is from the Oxford academic Thomas Barlow, thanking Hobbes for a copy of Hobbes's De homine; that copy also survives, and details are given of Barlow's critical annotations on it. Where the three non-extant letters are concerned, some information about them has been gleaned from entries in nineteenth-century dealers' and auctioneers' catalogues; in one case, a letter concerning telescopes from the marquess of Newcastle, those details are supplemented by other evidence, from Newcastle's household papers. Finally, some alleged items of Hobbes's correspondence are described and discounted, and two new manuscripts of known letters are listed.
Active Labour Market Policy and Unemployment Scarring: A Ten-year Swedish Panel Study
Authors: STRANDH MATTIAS , NORDLUND MADELENE
Published: June 2008

Previous studies have shown mixed results concerning the effects of participation in active labour market policy programmes (ALMPs) on the longer-term scars in the form of poor income development and low job stability following the end of an unemployment spell. Most previous studies, however, have been limited both in the time frame used and to particular programmes. We argue that human capital investments are long-term investments and should therefore also be investigated from a long-term perspective. ALMP training and ALMPs as subsidised employment also represent different types of human capital investments that may produce effects that are differently distributed over time. In order to handle these issues, this article uses a longitudinal register-based dataset in which all long-term (more than six months) unemployed Swedes in 1993, who had no labour market problems in 1992, were followed for ten years. We found positive effects of ALMP participation concerning both the probability of reaching pre-unemployment incomes and a reduction in the hazard of exiting the labour market, while the effect on the probability of having an unemployment-free year was mixed. The effects of the two forms of ALMPs were differently distributed over time, with ALMP employment having an immediate effect that decreased relatively quickly and ALMP training having a longer-term effect.
Social Policy Digest Online
Authors: Bennett Fran , Jones Ken
Published: June 2008

The Social Policy Digest went online in the summer of 2003. This means that the
Digest, which used to be printed as part of the Journal
of Social Policy, is now only available via the web.
Computer-aided-symbolic dynamic modeling for Stewart-platform manipulator
Authors: Lin J. , Chen C.-W.
Published: June 2008

The Stewart platform manipulator is a fully kinematic linkage system that has major mechanical differences from typical serial link robots. It is a six-axis parallel robot manipulator with a high force-to-weight ratio and good positioning accuracy that exceeds that of a conventional serial link robot arm. This study examines the dynamic equations and control methodology for a Stewart platform. Because manual symbolic expansion of Stewart platform robot dynamic equations is tedious, time-consuming, and prone to errors, an automated derivation process is highly desired. The main goal of this work is to present an efficient procedure for computer generation of dynamic equations for a Stewart platform manipulator. As MATLAB has a powerful signal processing toolbox along with symbolic processing capabilities and is widely used as a common technical computing environment in many universities and research laboratories, the objective of this study was to develop a MATLAB-based approach for symbolic computation for a parallel linked robot. Additionally, a computed-torque control methodology is utilized for such a structure. Simulation results demonstrate the effectiveness of the proposed control methodology.
REPEAT ANTENATAL CORTICOSTEROIDS: SHOULD IT BE PRESCRIBED AND IF SO WHEN AND HOW?
Authors: LEUNG TAK YEUNG , SAHOTA DALJIT SINGH
Published: June 2008

Corticosteroid treatment before preterm delivery was shown to be effective in reducing neonatal respiratory distress syndrome (RDS) more than three decades ago. The beneficial effect of steroids was further confirmed by Roberts and Dalziel's meta-analysis of 21 randomised controlled studies (RCT), which was published as a Cochrane Review in 2006. The authors concluded that the administration of a single course of steroids improved neonatal outcome, reducing RDS by 60%, periventricular haemorrhage (PVH) and necrotizing enterocolitis (NEC) by half, and neonatal death (NND) by 70%. However, these beneficial effects do not last for more than 7 days. Furthermore, steroids take at least 24 hours to be fully effective. Hence, it was advocated in the 1990's that regular weekly booster courses be given in order to maintain the therapeutic effects in high risk cases, as the timing of preterm birth cannot be readily predicted.
Plasma vitamin C: what does it measure?
Authors: Ness AR , Khaw KT , Bingham S , Day NE
Published: June 2008

Objective:

To examine the association between self-reported consumption of foods and plasma vitamin C levels.

Design:

A cross-sectional analysis of dietary data and plasma vitamin C levels. Subjects placed the following foods into frequency categories: fresh fruit, leafy greens, other vegetables, fatty fish, other fish, chicken, meat, meat products, eggs, cheese and brown bread. The six frequency categories ranged from ‘never’ to ‘at least daily’. Plasma vitamin C was measured by fluorometric assay.

Setting:

A population-based cohort study in Norfolk, UK.

Subjects:

598 men and 566 women aged 45–74 years not taking vitamin supplements.

Results:

Plasma vitamin C was positively correlated with intake of fresh fruit (r = 0.29 in men and r = 0.25 in women, P < 0.001), leafy greens (r = 0.20 in men P < 0.001, r = 0.13 in women P < 0.01), other vegetables (r = 0.20 in men P < 0.001, r = 0.14 in women P < 0.01) and brown bread (r = 0.28 in men, r = 0.17 in women, P < 0.001) and negatively associated with intake of meat products (r = −0.13 in men P = 0.02, r = −0.10 in women P < 0.01). The difference in plasma vitamin C between never and daily eaters of brown bread was 13.6 μmol l−1 in men and 9.9 μmol l−1 in women, P < 0.001

Conclusions:

These data suggest that plasma vitamin C is not only a marker of foods rich in vitamin C but of certain patterns of food consumption. Such patterns are likely to be population specific and might explain inconsistencies in biomarker–disease associations.
Transcriptional regulation of PSA-NCAM mediated neuron–glial plasticity in the adult hypothalamus
Authors: Parkash Jyoti , Kaur Gurcharan
Published: June 2008

Gonadotropin releasing hormone (GnRH)-secreting neurons in mammal's project principally to the median eminence-arcuate (ME-ARC) region where they make contact with basal lamina and open into the pericapillary space of the primary hypophyseal portal plexus. In the present study we report the expression of polysialylated form of neural cell adhesion molecule (PSA-NCAM) on the cell bodies of GnRH-secreting neurons and on glial cells in the medial preoptic area (mPOA) of the hypothalamus in both the proestrous and diestrous phases of cycling rats, using dual immunohistofluorescent staining. Regulation of PSA-NCAM occurs via regulation of PSA biosynthesis by the polysialyltransferase enzyme (PST-1). Therefore, we studied the expression of PST mRNA and GnRH in GnRH-releasing cell bodies by combining fluorescent in situ hybridization with immunohistofluorescence, and expression of PST mRNA in the mPOA using northern blotting. We observed dynamic upregulation of PSA-NCAM on GnRH cell bodies in the proestrous phase, accompanied by enhanced expression of PST-1 mRNA. The present results indicate that PSA-NCAM has a permissive role in the structural remodeling of GnRH neurons. Enhanced expression of mRNA encoding PST-1 in the proestrous phase indicates that the biosynthesis of PSA and, thus, PSA-NCAM is regulated at the transcriptional level.
Development of the online MM5 tracer model and its applications to air pollution episodes in Istanbul, Turkey and Sahara dust transport
Authors: Chen S.‐H. , Dudhia J. , Kain J. S. , Kindap T. , Tan E.
Published: June 2008

An online tracer model, based on the fifth‐generation Penn State/NCAR Mesoscale model, was developed. The new model includes full representation of processes for advection, boundary layer mixing, subgrid cumulus convective mixing, and sedimentation of tracers. The model was used in two very different applications to document its potential utility. The first application involves pollutant transport to Istanbul, Turkey, focusing on two high‐pollution episodes in January 2002. To better maintain large scale features, model simulations were nudged to reanalysis for this application. Using a semi‐idealized approach, it was shown that much of the pollution that affected Istanbul during these events may have come from other highly polluted cities located upstream, rather than just local emission sources. Pollutants from upstream sources were trapped in the boundary layer by statically stable low‐level conditions and efficient transport to Istanbul was supported by strong northwesterly flow near the surface. The second application involves the transport of dust from the Sahara Desert to the Atlantic Ocean, and the potential role of this dust and the dry, warm Saharan Air Layer (SAL) in the genesis and development of Tropical Storm Chantal in 2001. No nudging was applied to this case study since it may degrade small scale features, which were important to dust saltation. The dust uplifting and transport during the earlier period of Chantal's life cycle were simulated to show a potential link between Sahara dust and Chantal's evolution. Results show strong evidence that Chantal started interacting with SAL and dust at a very early stage of storm development after propagating into the eastern Atlantic Ocean. Moreover, it was found that the peak of the averaged surface dust flux occurred in the early morning right before the mixed boundary layer developed, and the mechanism of dust uptake for this event, nocturnal low‐level jets, was different from those previously documented.
Importance of anthropogenic inputs and continental‐derived dust for the distribution and flux of water‐soluble nitrogen and phosphorus species in aerosol within the atmosphere over the East China Sea
Authors: Chen Hung‐Yu , Chen Liang‐De
Published: June 2008

We analyzed 156 aerosol samples, including 10 dust storm samples, collected from January to December 2005 at a coastal site on the southern East China Sea at Keelung city, Taiwan, for water‐soluble major ions, nitrogen, and phosphorus species. In addition, 4‐d back trajectories of air masses arriving daily at the sampling site were calculated to determine the potential aerosol source regions. The obtained concentrations of major ions indicate that a continental source was dominant from January to May and from November to December, a local source during July, and an oceanic source from September to October. The measured atmospheric concentrations of nitrogen and phosphorus species show clear seasonal variations and correspond to the different sources and weather conditions. During the dust storm period, dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) concentrations showed statistically significant linear relationships with the amount of aerosol particles, suggesting a continental source. The results of a factor analysis of combined major ions and DIN and DIP indicate that crustal sources, marine sources, and combustion sources are the three major controlling factors during the non‐dust‐storm period. Natural and anthropogenic land sources and marine sources are the most influential factors in terms of the distribution of aerosol during the dust storm period. A strong correlation was also found between DIN and DIP, indicating similar sources and transportation mechanisms. The results of flux calculations indicate that aerosols derived from dust storms and biomass burning provide 12 ± 8% and 46 ± 36% of total DIN and 16 ± 10% and 46 ± 38% of total DIP, respectively. Consequently, the inputs of aerosol derived from biomass burning may be an important source of nitrogen and phosphorus in aerosols over the East China Sea.
Fat Infiltration in Muscle: New Evidence for Familial Clustering and Associations With Diabetes
Authors: Miljkovic‐Gacic Iva , Wang Xiaojing , Kammerer Candace M. , Gordon Christopher L. , Bunker Clareann H. , Kuller Lewis H. , Patrick Alan L. , Wheeler Victor W. , Evans Rhobert W. , Zmuda Joseph M.
Published: June 2008

Objective: Increased fat infiltration in skeletal muscle has been associated with diabetes. Quantitative computed tomography (QCT) can be used to measure muscle density, which reflects the lipid content of skeletal muscle such that greater fat infiltration in skeletal muscle is associated with lower muscle density. The relative contribution of genetic and environmental factors to fat infiltration in skeletal muscle has not been assessed. Therefore, our aim is to determine genetic and environmental contributions to measures of skeletal muscle composition, and describe their associations with type 2 diabetes in multigenerational families of African ancestry.

Methods and Procedures: Peripheral QCT (pQCT) measures of skeletal muscle density were obtained for the calf in 471 individuals (60% women; mean 43 years) belonging to eight large, multigenerational Afro‐Caribbean families (mean family size 51 individuals; 3,535 relative pairs).

Results: The proportion of variance in muscle density due to additive genetic effects (residual heritability) was 35.0% (P < 0.001) and significant covariates (age, gender, BMI, and parity) explained 55.0% of the total phenotypic variation in muscle density. Muscle density was lower (P < 0.001) in 62 diabetics (69.5 mg/cm3) than in 339 nondiabetics (74.3 mg/cm3) and remained significant after adjusting for age, gender, and BMI (P = 0.005) or age, gender, and waist circumference (P = 0.01).

Discussion: Our results provide new evidence that ectopic lipid deposition in skeletal muscle is a heritable trait and is associated with diabetes, independent of overall and central obesity in families of African heritage. Genome‐wide screens and candidate gene studies are warranted to identify the genetic factors contributing to ectopic deposition of skeletal muscle fat.
Serum Resistin and Polymorphisms of Androgen Receptor CAGn and GGNn and Aromatase TTTAn
Authors: Hernández A. González , de León A. Cabrera , Coello S. Dominguez , González D. Almeida , Pérez M. C. Rodríguez , Díaz B. Brito , Aguirre‐Jaime A. , Díaz‐Chico B. N.
Published: June 2008

There is evidence that androgens are regulators of insulin resistance (IR), and may be involved in the regulation of resistin, a cytokine that has been related with IR. Earlier studies found that androgen receptor length polymorphisms CAGn and GGNn and the aromatase polymorphism TTTAn may influence receptor or enzyme activity and serum concentrations of androgens. This study was designed to determine whether polymorphism length was related to serum resistin concentration and to other variables related with IR. In 1,580 persons chosen randomly from the general population of the Canary Islands (Spain), we measured polymorphism length, waist circumference, waist/hip ratio, BMI, and serum glucose concentration. In smaller subgroups, we also measured C‐peptide (n = 677), resistin (n = 583), and leptin concentration (n = 754) and estimated IR (homeostasis model assessment‐IR (HOMA2‐IR)). In men, polymorphism length correlated with resistin concentration (CAGn, r = 0.13, P = 0.031; TTTAn, r = 0.15, P = 0.005; GGNn, r = −0.15, P = 0.026), and the correlations were confirmed in multivariate regression models. The length of CAGn and TTTAn correlated inversely with C‐peptide (r = −0.13, P = 0.016 and r = −0.21, P < 0.001, respectively) and with estimated IR (r = −0.12, P = 0.032 and r = −0.19, P = 0.001, respectively). In men, length of the CAGn, GGNn, and TTTAn was associated with serum resistin concentration. These results support the hypothesis that androgens may be involved in the regulation of resistin. Resistin may be a link between IR and androgens.
Ionic correlations in the inhomogeneous atmosphere surrounding cylindrical polyions: Catalytic effects of polyions
Authors: Piñero J. , Bhuiyan L. B. , Reščič J. , Vlachy V.
Published: June 2008

The structural properties of linear polyelectrolyte solutions in the presence of a salt as evidenced through ionic correlations in the inhomogeneous atmosphere around a polyion and their consequence such as the catalytic potential are studied by using Monte Carlo simulation techniques. The simulations are performed on the cylindrical cell model where a uniformly charged hard cylinder mimics the linear polyion, which is caged in its own cylindrical cell containing counterions and salt. The cell (volume) average of the interionic correlations is presented as a function of the polyion and salt concentrations and ion radius. These results are utilized to study the catalytic effects of polyions as manifested through the changes in the collision frequency between ions in the double layer surrounding the polyion relative to that in the pure electrolyte solution. The reported results suggest a strong influence of the added salt/polyelectrolyte concentration ratio on the structural properties of the solution and hence on ion-ion collision frequency. The machine simulations are supplemented by nonlinear Poisson-Boltzmann results. Fair agreement between two different theoretical methods of calculating the collision frequency is obtained.
Sum-frequency generation: Polarization surface spectroscopy analysis of the vibrational surface modes on the basal face of ice Ih
Authors: Groenzin Henning , Li Irene , Shultz Mary Jane
Published: June 2008

In recent years, sum-frequency generation (SFG) has been used to investigate numerous interfaces including aqueous interfaces. A longstanding challenge to interpretation of the SFG results, along with the related aqueous-solution infrared and Raman spectra, is a lack of connection between features in the broad hydrogen-bonded region and molecular-level interactions or configurations. This paper reports results of a newly developed polarization analysis of the generated sum-frequency signal as a function of wavelength both to deconvolute spectral resonances and to characterize the dynamic polarization associated with the resonances. Operationally, the polarization angle of the generated sum frequency is determined by identifying the null angle. The technique is hence termed polarization-angle null analysis or PAN. PAN applied to ice is very powerful; it reveals that the hydrogen-bonded region of the basal face of ice Ih contains at least five oscillators, each with a distinct polarization. The dynamic polarizability of the longest wavelength oscillator is nearly entirely transverse (perpendicular to the surface normal, i.e., in the surface plane); in contrast, the shortest wavelength oscillator is almost entirely longitudinal (along the surface normal).
Nonlinear theory of kinetic Alfvén waves propagation and multiple filament formation
Authors: Sharma R. P. , Malik M. , Singh H. D.
Published: June 2008

In this paper, the filamentation of kinetic Alfvén waves (KAWs) has been studied by assuming that the incident Gaussian beam of KAWs may not remain Gaussian during the filament formation. The solution of the nonlinear dynamical equation of KAWs has been obtained by developing the semi-analytical approach in solar wind plasma. Magnetic field structures of the KAW have been presented in x-z plane. The analytical theory using eikonal approximation has been used beyond the paraxial domain. The effect on spectral index of the turbulence has also been studied.
Electronic properties of self-assembled alkyl monolayers on Ge surfaces
Authors: Sharp I. D. , Schoell S. J. , Hoeb M. , Brandt M. S. , Stutzmann M.
Published: June 2008

Covalent attachment of alkyl monolayers on (111) and (100) oriented Ge surfaces was achieved via thermal hydrogermylation with 1-octadecene (C18H36), a process which is directly analogous to the well-known hydrosilylation reaction on Si. Current-voltage (IV) and high frequency capacitance-voltage (CV) measurements were performed on these metal-insulator-semiconductor structures with a liquid Hg contact to the organic layers. Strongly rectifying diodes with no surface Fermi level pinning are observed and the specific interfacial band bending is determined for both intrinsic and moderately n-type doped samples.
Improvement of Drought Tolerance and Grain Yield in Common Bean by Overexpressing Trehalose-6-Phosphate Synthase in Rhizobia
Authors: Suárez Ramón , Wong Arnoldo , Ramírez Mario , Barraza Aarón , Orozco María del Carmen , Cevallos Miguel A. , Lara Miguel , Hernández Georgina , Iturriaga Gabriel
Published: June 2008

Improving stress tolerance and yield in crops are major goals for agriculture. Here, we show a new strategy to increase drought tolerance and yield in legumes by overexpressing trehalose-6-phosphate synthase in the symbiotic bacterium Rhizobium etli. Phaseolus vulgaris (common beans) plants inoculated with R. etli overexpressing trehalose-6-phosphate synthase gene had more nodules with increased nitrogenase activity and higher biomass compared with plants inoculated with wild-type R. etli. In contrast, plants inoculated with an R. etli mutant in trehalose-6-phosphate synthase gene had fewer nodules and less nitrogenase activity and biomass. Three-week-old plants subjected to drought stress fully recovered whereas plants inoculated with a wild-type or mutant strain wilted and died. The yield of bean plants inoculated with R. etli overexpressing trehalose-6-phosphate synthase gene and grown with constant irrigation increased more than 50%. Macroarray analysis of 7,200 expressed sequence tags from nodules of plants inoculated with the strain overexpressing trehalose-6-phosphate synthase gene revealed upregulation of genes involved in stress tolerance and carbon and nitrogen metabolism, suggesting a signaling mechanism for trehalose. Thus, trehalose metabolism in rhizobia is key for signaling plant growth, yield, and adaptation to abiotic stress, and its manipulation has a major agronomical impact on leguminous plants.
A Novel Plant Ferredoxin-Like Protein and the Regulator Hor Are Quorum-Sensing Targets in the Plant Pathogen Erwinia carotovora
Authors: Sjöblom Solveig , Harjunpää Heidi , Brader Günter , Palva E. Tapio
Published: June 2008

Quorum sensing (QS), a population-density-sensing mechanism, controls the production of the main virulence determinants, the plant cell-wall-degrading enzymes (PCWDEs) of the soft-rot phytopathogen Erwinia carotovora subsp. carotovora. In this study, we used random transposon mutagenesis with a gusA reporter construct to identify two new QS-controlled genes encoding the regulator Hor and a plant ferredoxin-like protein, FerE. The QS control of the identified genes was executed by the QS regulators ExpR1 and ExpR2 and mediated by the global repressor RsmA. Hor was shown to contribute to bacterial virulence at least partly through its control of PCWDE production. Our results showed that FerE contributes to oxidative stress tolerance and in planta fitness of the bacteria and suggest that QS could be central to control of oxidative stress tolerance. The presence of the FerE protein appears to be rather unique in heterotrophic bacteria and suggests an acquisition of the corresponding gene from plant host by horizontal gene transfer.
George Patrick John Rushworth Jellicoe, 2nd Earl Jellicoe. 4 April 1918 — 22 February 2007
Authors: Waldegrave William
Published: June 2008

George Jellicoe had at least five (and very nearly six) different careers, all of them successful. Two of them were brought to an end as the result of separate imbroglios involving women, the contemporary reactions to which now seem antique—particularly the first, involving as it did Foreign Office disapproval of the break–up of his first marriage, an event that led to his exceptionally happy second marriage to Philippa Dunne. In all of his careers, however—as soldier and first commander of the Special Boat Service (SBS); as diplomat; as Minister and politician;as businessman; and as champion of science, and particularly medical science, in Whitehall and Westminster—he left unusual stocks of affection and admiration behind him, whether among the Cretanpeasants alongside whom he fought the Germans, or the Fellows of the Royal Society with whom he fought the Treasury. A sixth career as Olympic sportsman might have been his if he had chosen: in1948 he was invited to train with the British Winter Olympics team, either for the Cresta Run or as a skier.
Hybridization versus conservation: are domestic cats threatening the genetic integrity of wildcats (Felis silvestris silvestris) in Iberian Peninsula?
Authors: Oliveira Rita , Godinho Raquel , Randi Ettore , Alves Paulo C
Published: June 2008

Cross-breeding between wild and free-ranging domestic species is one of the main conservation problems for some threatened species. The situation of wildcats (Felis silvestris silvestris) in Europe is a good example of this critical phenomenon. Extensive hybridization was described in Hungary and Scotland, contrasting with occasional interbreeding in Italy and Germany. First analyses in Portugal revealed a clear genetic differentiation between wild and domestic cats; however, four hybrids were detected. Here, we extended the approach to Iberian Peninsula using multivariate and Bayesian analyses of multilocus genotypes for 44 Portuguese wildcats, 31 Spanish wildcats and 109 domestic cats. Globally, wild and domestic cats were significantly differentiated (FST=0.20,p<0.001) and clustered into two discrete groups. Diverse clustering methods and assignment criteria identified an additional hybrid in Portugal, performing a total of five admixed individuals. The power of admixture analyses was assessed by simulating hybrid genotypes, which revealed that used microsatellites were able to detect 100, 91 and 85% of first-generation hybrids, second-generation genotypes and backcrosses, respectively. These findings suggest that the true proportion of admixture can be higher than the value estimated in this study and that the improvement of genetic tools for hybrids detection is crucial for wildcat conservation.
Sympatric, parapatric or allopatric: the most important way to classify speciation?
Authors: Butlin Roger K , Galindo Juan , Grahame John W
Published: June 2008

The most common classification of modes of speciation begins with the spatial context in which divergence occurs: sympatric, parapatric or allopatric. This classification is unsatisfactory because it divides a continuum into discrete categories, concentrating attention on the extremes, and it subordinates other dimensions on which speciation processes vary, such as the forces driving differentiation and the genetic basis of reproductive isolation. It also ignores the fact that speciation is a prolonged process that commonly has phases in different spatial contexts. We use the example of local adaptation and partial reproductive isolation in the intertidal gastropodLittorina saxatilisto illustrate the inadequacy of the spatial classification of speciation modes. Parallel divergence in shell form in response to similar environmental gradients in England, Spain and Sweden makes this an excellent model system. However, attempts to demonstrate ‘incipient’ and ‘sympatric’ speciation involve speculation about the future and the past. We suggest that it is more productive to study the current balance between local adaptation and gene flow, the interaction between components of reproductive isolation and the genetic basis of differentiation.
Temporal coherence of aboveground net primary productivity in mesic grasslands
Authors: Heisler Jana L. , Knapp Alan K.
Published: June 2008

Synchrony in ecological variables over wide geographic areas suggests that large‐scale environmental factors drive the structure and function of ecosystems and override more local‐scale environmental variation. Described also as coherence, this phenomenon has been documented broadly in the ecological literature and has recently received increasing attention as scientists attempt to quantify the impacts of global changes on organisms and their habitats. Using a mesic grassland site in North America, we assessed coherence in ecosystem function by quantifying similarity in aboveground net primary production (ANPP) dynamics in 48 permanent sampling locations (PSLs) over a 16‐yr period. Our primary objective was to characterize coherence across a broad geographic region (with similar ecosystem structure and function), and we hypothesized that precipitation and a similar fire frequency would strengthen coherence between PSLs. All 48 PSLs at our site (Konza Prairie Biological Station, Manhattan, KS, USA; KPBS) were exposed to a similar regional driver of ANPP (precipitation); however, local drivers (including differences in fire frequency and soil depth at different topographic positions) varied strongly among individual PSLs. For the purpose of this assessment, the watershed‐level experimental design of KPBS was considered a model, which represented different fire management strategies across the Great Plains Region. Our analyses revealed a site‐level (KPBS) coherence in ANPP dynamics of 0.53 for the period of 1984–1999. Annual fire enhanced coherence among PSLs to 0.76, whereas less frequent fire (fire exclusion or a 4‐yr fire return interval) failed to further increase coherence beyond that of the KPBS site level. Soil depth also strongly influenced coherence among PSLs with shallow soils at upland sites showing strong coherence across fire regimes and annually burned uplands closely linked to annual precipitation dynamics. The lack of coherence in ecosystem function in PSLs with deep soils and low fire frequencies suggests that conservation and management efforts will need to be more location specific in such areas where biotic interactions may be more important than regional abiotic drivers.
New mutations in C1GALT1C1 in individuals with Tn positive phenotype
Authors: Karamatic Crew Vanja , Singleton Belinda K. , Green Carole , Parsons Stephen F. , Daniels Geoff , Anstee David J.
Published: June 2008

Tn polyagglutination results from inactivating mutations in C1GALT1C1, an X‐borne gene encoding a core 1 β3‐galactosyltransferase‐specific molecular chaperone (cosmc) required for the functioning of T‐synthase (β 1,3‐galactosyltransferase), a glycosyltransferase essential for the correct biosynthesis of O‐glycans. This study found novel inactivating mutations (Glu152Lys, Ser193Pro and Met1Ile) in the coding sequence of C1GALT1C1 in three Tn positive individuals and a complete lack of C1GALT1C1 cDNA expression was observed in an additional Tn positive individual. In addition, expression of ST6GALNAC1, which encodes (α‐N‐acetyl‐neuraminyl‐2,3‐β‐galactosyl‐1, 3)‐N‐acetylgalactosaminide α‐2,6‐sialyltransferase 1 and gives rise to sialyl‐Tn antigen, was present at comparable levels in normal and Tn‐positive human erythroblasts. Expression studies of wild‐type and Tn positive C1GALT1C1 cDNA in the Jurkat cell line confirmed that the amino acid substitutions observed in Tn are inactivating. Analysis of the transcriptome of cultured normal and Tn positive erythroblasts revealed numerous differences in gene expression. Reduced transcript levels for fatty acid binding protein 5 (FABP5) and plexin D1 (PLXND1), and increased levels for aquaporin 3 (AQP3) were confirmed by quantitative real‐time polymerase chain reaction. These data show that alteration of O‐glycan structures resulting from T‐synthase deficiency is accompanied by altered expression of a wide variety of genes in erythroid cells.
CD39 is incorporated into plasma microparticles where it maintains functional properties and impacts endothelial activation
Authors: Banz Yara , Beldi Guido , Wu Yan , Atkinson Ben , Usheva Anny , Robson Simon C.
Published: June 2008

Plasma microparticles (MPs, <1·5 μm) originate from platelet and cell membrane lipid rafts and possibly regulate inflammatory responses and thrombogenesis. These actions are mediated through their phospholipid‐rich surfaces and associated cell‐derived surface molecules. The ectonucleotidase CD39/ecto‐nucleoside triphosphate diphosphohydrolase1 (E‐NTPDase1) modulates purinergic signalling through pericellular ATP and ADP phosphohydrolysis and is localized within lipid rafts in the membranes of endothelial‐ and immune cells. This study aimed to determine whether CD39 associates with circulating MPs and might further impact phenotype and function. Plasma MPs were found to express CD39 and exhibited classic E‐NTPDase ecto‐enzymatic activity. Entpd1 (Cd39) deletion in mice produced a pro‐inflammatory phenotype associated with quantitative and qualitative differences in the MP populations, as determined by two dimensional‐gel electrophoresis, western blot and flow cytometry. Entpd1‐null MPs were also more abundant, had significantly higher proportions of platelet‐ and endothelial‐derived elements and decreased levels of interleukin‐10, tumour necrosis factor receptor 1 and matrix metalloproteinase 2. Consequently, Cd39‐null MP augment endothelial activation, as determined by inflammatory cytokine release and upregulation of adhesion molecules in vitro. In conclusion, CD39 associates with circulating MP and may directly or indirectly confer functional properties. Our data also suggest a modulatory role for CD39 within MP in the exchange of regulatory signals between leucocytes and vascular cells.
Enduring consequences of parenting for risk behaviors from adolescence into early adulthood
Authors: Reading Richard
Published: June 2008

.
 
Roche K. M.,
Ahmed S. &
Blum R. W.
(
2008
)

,
66
,
2023
–
2034
.
 
DOI: 10.1016/j.socscimed.2008.01.009
.
Effects of prolonged and exclusive breastfeeding on child behavior and maternal adjustment: evidence from a large, randomized trial
Authors: Reading Richard
Published: June 2008

.
 
Kramer M. S.,
Fombonne E.,
Igumnov S.,
Vanilovich I.,
Matush L.,
Mironova E.,
Bogdanivich N.,
Tremblay R. E.,
Chalmers B.,
Zhang X. &
Platt R. W.
,
for the PROBIT study group
(
2008
)

,
121
,
e435
–
e440
.
 
DOI: 10.1542/peds.2007‐1248
.

Objective  The objective of this study was to assess the long‐term effects of breastfeeding on child behaviour and maternal adjustment.

Methods  We followed up children who were in the Promotion of Breastfeeding Intervention Trial, a cluster‐randomized trial of a breastfeeding promotion intervention based on the World Health Organization/United Nations Children's Fund Baby‐Friendly Hospital Initiative. A total of 17 046 healthy, breastfeeding mother–infant pairs were enrolled from 31 Belarussian maternity hospitals and affiliated polyclinics; 13 889 (81.5%) were followed up at 6.5 years. Mothers and teachers completed the Strengths and Difficulties Questionnaire and supplemental questions bearing on internalizing and externalizing behavioural problems. Mothers also responded to questions concerning their relationships to their partner and child and their breastfeeding of subsequently born children.

Results  The experimental intervention led to a large increase in exclusive breastfeeding at 3 months (43.3% vs. 6.4%) and a significantly higher prevalence of any breastfeeding at all ages up to and including 12 months. No significant treatment effects were observed on either the mother or the teacher Strengths and Difficulties Questionnaire ratings of total difficulties, emotional symptoms, conduct problems, hyperactivity, peer problems, or prosocial behaviour or on the supplemental behavioural questions. We found no evidence of treatment effects on the parent's marriage or on the mother's satisfaction with her relationships with her partner or child, but the experimental intervention significantly increased the duration of any breastfeeding, and mothers in the experimental group were nearly twice as likely to breastfeed exclusively the next‐born child for at least 3 months.

Conclusions  On the basis of the largest randomized trial ever conducted in the area of human lactation, we found no evidence of risks or benefits of prolonged and exclusive breastfeeding for child and maternal behaviour. Breastfeeding promotion does, however, favourably affect breastfeeding of the subsequent child.
Chronic obstructive pulmonary disease in patients admitted with heart failure
Authors: Iversen K. K. , Kjaergaard J. , Akkan D. , Kober L. , Torp‐Pedersen C. , Hassager C. , Vestbo J. , Kjoller E. ,   The ECHOS‐Lung Function Study Group
Published: June 2008

Objective.  Chronic obstructive pulmonary disease (COPD) is an important differential diagnosis in patients with heart failure (HF). The primary aims were to determine the prevalence of COPD and to test the accuracy of self‐reported COPD in patients admitted with HF. Secondary aims were to study a possible relationship between right and left ventricular function and pulmonary function.

Design.  Prospective substudy.

Setting.  Systematic screening at 11 centres.

Subjects.  Consecutive patients (n = 532) admitted with HF requiring medical treatment with diuretics and an episode with symptoms corresponding to New York Heart Association class III‐IV within a month prior to admission.

Interventions.  Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were measured by spirometry and ventricular function by echocardiography. The diagnosis of COPD and HF were made according to established criteria.

Results.  The prevalence of COPD was 35%. Only 43% of the patients with COPD had self‐reported COPD and one‐third of patients with self‐reported COPD did not have COPD based on spirometry. The prevalence of COPD in patients with preserved left ventricular ejection fraction (i.e. LVEF ≥45%) was significantly higher than in patients with impaired LVEF (41% vs. 31%, P = 0.03). FEV1 and FVC were negatively correlated with right ventricular end‐diastolic diameter and tricuspid annular plane systolic excursion and FVC positively correlated with systolic gradient across the tricuspid valve.

Conclusion.  Chronic obstructive pulmonary disease is frequent in patients admitted with HF and self‐reported COPD only identifies a minority. The prevalence of COPD was high in both patients with systolic and nonsystolic HF.