bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathways to Economic Well-Being Among Teenage Mothers in Great Britain
Authors: Schoon Ingrid , Polek Elzbieta
Published: June 2010

The present study examines pathways to independence from social welfare among 738 teenage mothers, participants of the 1970 British Cohort Study, who were followed up at age 30 years. Using a longitudinal design, a pathway model is tested, examining linkages between family social background, cognitive ability, school motivation, and individual investments in education, as well as work- and family-related roles. The most important factors associated with financial independence by age 30 are continued attachment to the labor market as well as a stable relationship with a partner (not necessarily the father of the child). Pathways to financial independence, in turn, are predicted through own cognitive resources, school motivation, and family cohesion. Implications of findings for policy making are discussed.
Interpersonal Identity Development in Different Groups of Siblings
Authors: Watzlawik Meike , Clodius Sandrine
Published: June 2010

With the help of German versions of the modified Utrecht-Groningen Identity Development Scales, we assessed interpersonal identity development of five different groups of siblings. Monozygotic, dizygotic same-sexed, and opposite-sexed twins, as well as same-sexed and opposite-sexed siblings (N = 214; average age 11.2, SD = 1.4) were interviewed three times (time interval: 1 year) in their home environments to examine commitment and exploration in the life domains siblings, best friends, and romantic relationships at each visit, as well as changes over time. Hierarchical analyses showed that, in general, the type of sibling dyad was not related to interpersonal identity development. Only monozygotic twins – being of the same genotype, same sex, and same age – derive more self-esteem from their sibling relationships. In general, a decrease in commitment toward the sibling and an increase of exploration in the life domains best friends and romantic relationships could be observed in all adolescents.
Unlucky Victims or Lucky Survivors?
Authors: Teigen Karl Halvor , Jensen Tine K.
Published: June 2010

Subjective experiences of good or bad luck appear to depend upon downward or upward comparisons with close counterfactuals. People exposed to disasters have both options: They were at the wrong place at the wrong time, but their fate could in many cases have been worse; so in a sense, they are unlucky victims, but lucky survivors. Interviews with 85 Norwegian tourists 9–11 months after they had been exposed to the tsunami disaster in Southeast Asia showed good luck to be a pivotal theme in a majority of the narratives. Nobody claimed they had been unfortunate or unlucky. Moreover, downward counterfactual thoughts and downward comparisons with others occurred 10 times more often than upward counterfactuals and upward comparisons. In a follow-up 2 years later, 95% answered they had been lucky. A contextual analysis revealed several facets of luck, including its relation to gratitude, guilt, and supernatural beliefs.
Anthropogenic nitrogen autotrophy and heterotrophy of the world's watersheds: Past, present, and future trends
Authors: Billen Gilles , Beusen Arthur , Bouwman Lex , Garnier Josette
Published: June 2010

Anthropogenic nitrogen autotrophy of a territory is defined as the nitrogen flux associated with local production of harvested crops and grass consumed by livestock grazing (in kg N/km2/yr). Nitrogen heterotrophy is the nitrogen flux associated with local food and feed consumption by humans and domestic animals. These two summarizing characteristics (anthropogenic nitrogen autotrophy and heterotrophy (ANAH)) indicate the degree of anthropogenic perturbation of the nitrogen cycle by agriculture and human consumption: their balance value provides information on either the potential for commercial export or the need to import agricultural goods; in a watershed, their vector sum is related to the nitrogen flux delivered to the sea. These indicators were calculated for all the watersheds in the Global Nutrient Export from Watersheds (NEWS) database for 1970 and 2000, as well as for 2030 and 2050, according to Millennium Ecosystem Assessment scenarios. During this 30 year period, many watersheds shifted from relatively balanced situations toward either more autotrophic or more heterotrophic conditions. This trend is predicted to become more pronounced over the next 50 years.
A comparison of EISCAT and SuperDARN F‐region measurements with consideration of the refractive index in the scattering volume
Authors: Gillies R. G. , Hussey G. C. , Sofko G. J. , Wright D. M. , Davies J. A.
Published: June 2010

Gillies et al. (2009) proposed the use of interferometric measurements of the angle of arrival as a proxy for the scattering region refractive index ns needed to estimate the line‐of‐sight Doppler velocity of the ionospheric plasma from HF [Super Dual Auroral Radar Network (SuperDARN)] radar observations. This study continues this work by comparing measurements of line‐of‐sight velocities by SuperDARN with tristatic velocity measurements by the EISCAT incoherent scatter radar from 1995 to 1999. From a statistical viewpoint, velocities measured by SuperDARN were lower than velocities measured by EISCAT. This can, at least partially, be explained by the neglect in the SuperDARN analysis of the lower‐than‐unity refractive index of the scattering structures. The elevation angle measured by SuperDARN was used as a proxy estimate of ns and this improved the comparison, but the velocities measured by SuperDARN were still lower. Other estimates of ns using electron densities Ne based on both EISCAT measurements and International Reference Ionosphere model values did not increase the SuperDARN velocities enough to attain the EISCAT values. It is proposed that dense structures that were of comparable size to the SuperDARN scattering volume partially help resolve the low‐velocity issue. These dense, localized structures would provide the Ne gradients required for generation of the coherent irregularities from which the SuperDARN radar waves scatter, whereas EISCAT incoherent radar measurements provide only the background Ne and not the density of the small‐scale structures. The low‐velocity SuperDARN results suggest that small‐scale dense structures with refractive indices well below unity must exist within the SuperDARN scattering volume and may contribute greatly to the scattering process.
Wave forcing in the stratosphere under doubled‐CO2 conditions in a 100‐year coupled chemistry‐climate model study
Authors: Winter B. , Bourqui M.
Published: June 2010

The impact of doubling atmospheric CO2 on the resolved‐wave forcing of the stratospheric flow, and thus on the Brewer‐Dobson circulation (BDC), is investigated with 100‐year timeslice simulations using a chemistry‐climate model, the IGCM‐FASTOC, coupled to a mixed‐layer slab ocean. The Arctic lower stratosphere in winter warms by up to 4 K, with associated weakening of the polar vortex and enhancement of the BDC. This change is related to a significant increase in the wave forcing near the vortex core starting in January, followed by an increased wave forcing at the lower edge of the polar vortex in February. Maximum wave forcing is found both to occur earlier in the winter and to be distributed over a longer period of time in the 2 × CO2 climate. The sensitivity to surface conditions is studied by repeating the CO2‐doubling experiments with prescribed interannually varying and fixed annual cycle monthly mean surface temperatures. In the absence of interannual variability, the BDC response is strongly attenuated. With interannual variability, the monthly mean prescribed surface temperatures lead to a similar dynamical response in the stratosphere as found with the interactive surface but with reduced magnitude.
Trend discrepancies among three best track data sets of western North Pacific tropical cyclones
Authors: Song Jin‐Jie , Wang Yuan , Wu Liguang
Published: June 2010

The hot debate over the influence of global warming on tropical cyclone (TC) activity in the western North Pacific over the past several decades is partly due to the diversity of TC data sets used in recent publications. This study investigates differences of track, intensity, frequency, and the associated long‐term trends for those TCs that were simultaneously recorded by the best track data sets of the Joint Typhoon Warning Center (JTWC), the Regional Specialized Meteorological Center (RSMC) Tokyo, and the Shanghai Typhoon Institute (STI). Though the differences in TC tracks among these data sets are negligibly small, the JTWC data set tends to classify TCs of category 2–3 as category 4–5, leading to an upward trend in the annual frequency of category 4–5 TCs and the annual accumulated power dissipation index, as reported by Webster et al. (2005) and Emanuel (2005). This trend and potential destructiveness over the period 1977–2007 are found only with the JTWC data set, but downward trends are apparent in the RSMC and STI data sets. It is concluded that the different algorithms used in determining TC intensity may cause the trend discrepancies of TC activity in the western North Pacific.
New Gulf Oil Leak Estimates Dwarf Original Figures
Authors: Showstack Randy
Published: June 2010

New estimates of the amount of oil flowing from BP's leaking oil well in the Gulf of Mexico are dramatically higher than initial numbers, according to figures released by U.S. Secretary of Energy Steven Chu, Secretary of the Interior Ken Salazar, and U.S. Geological Survey Director Marcia McNutt on 15 June. “The most likely flow rate of oil today is between 35,000 and 60,000 barrels per day,” based on estimates by U.S. government and independent scientists, they indicated.

“This estimate brings together several scientific methodologies and the latest information from the seafloor and represents a significant step forward in our effort to put a number on the oil that is escaping from BP's well,” Chu indicated. He noted the numbers could change with the collection of additional data, and he added that the administration has been focusing on responding to the upper end of the flow estimate.
Environmental, Geopolitical Change in the Arctic
Authors: Showstack Randy
Published: June 2010

With climate change rapidly transforming environmental and geopolitical conditions in the Arctic region, scientists and policy makers are calling for improved science observation capabilities and more attention to the region.

“We do not have a satisfactory observational capability in the Arctic, on the ground, using aircraft, or using satellites and spaceborne instruments,” said Martin Jeffries, program director of the Arctic Observing Network in the U.S. National Science Foundation's (NSF) Office of Polar Programs. He was one of the speakers at the 9 June Forum on Earth Observations IV, held in Washington, D.C. He noted that many U.S. federal agencies are engaged in data gathering and that NSF is working with some agencies to develop an interagency Arctic observing network.
Telling Others About the Science of Earth and Sky
Authors: Stern David P.
Published: June 2010

Public concerns nowadays often require familiarity with geophysics and astronomy. Many people wonder or worry about climate change, the greenhouse effect, nuclear energy, and energy in general, as well as space research, solar eruptions, magnetic fields inside and outside Earth, and space radiation. How can these people, including students and teachers, find out about such subjects?

Many turn to Wikipedia™. It can be quite useful, but this is an encyclopedia—often going into excessive detail, occasionally misleading (anyone can modify it), and rarely placing subjects in the broader context in which they belong. Just look up some of the subjects listed above! The general public, as well as students learning about Earth and space science, seek guidance, not just descriptions of subjects but also help in understanding them and placing them in an overall pattern.
AGU Scientists “Rock” Capitol Hill for Congressional Visits Day
Authors: Chell Kaitlin
Published: June 2010

Although Earth and space sciences may not always make national headlines, they are woven into a multitude of national policies that affect people in the United States and around the world. Issues such as energy, environment, hazards, and climate consistently are on the legislative docket of the U.S. Congress, and as a result, policy makers need to hear from Earth and space scientists who can offer their expertise. Twenty‐nine AGU members from 16 states did just that during the fifteenth annual Science‐Engineering‐Technology Congressional Visits Day (SET‐CVD) event on 28–29 April. AGU joined forces with dozens of other scientific and engineering societies, bringing nearly 300 scientists and engineers from across the country to Capitol Hill.
Caylor Receives 2009 Early Career Hydrologic Sciences Award
Authors: Rodríguez‐Iturbe Ignacio , Caylor Kelly C.
Published: June 2010

Kelly K. Caylor received the 2009 Early Career Hydrologic Sciences Award at the 2009 AGU Fall Meeting, held 14–18 December in San Francisco, Calif. The award is for significant early contributions to hydrologic science.
PIP4Kβ interacts with and modulates nuclear localization of the high-activity PtdIns5P-4-kinase isoform PIP4Kα
Authors: Bultsma Yvette , Keune Willem-Jan , Divecha Nullin
Published: June 2010

The β-isoform of PIP4K (PtdIns5P-4-kinase) regulates the levels of nuclear PtdIns5P, which in turn modulates the acetylation of the tumour suppressor p53. The crystal structure of PIP4Kβ demonstrated that it can form a homodimer with the two subunits arranged in opposite orientations. Using MS, isoform-specific antibodies against PIP4Ks, RNAi (RNA interference) suppression and overexpression studies, we show that PIP4Kβ interacts in vitro and in vivo with the PIP4Kα isoform. As the two isoforms phosphorylate the same substrate to generate the same product, the interaction could be considered to be functionally redundant. However, contrary to expectation, we find that PIP4Kβ has 2000-fold less activity towards PtdIns5P compared with PIP4Kα, and that the majority of PIP4K activity associated with PIP4Kβ comes from its interaction with PIP4Kα. Furthermore, PIP4Kβ can modulate the nuclear localization of PIP4Kα, and PIP4Kα has a role in regulating PIP4Kβ functions. The results of the present study suggest a rationale for the functional interaction between PIP4Kα and PIP4Kβ and provide insight into how the relative levels of the two enzymes may be important in their physiological and pathological roles.
Mesenchymal stromal cells improve renal injury in anti-Thy 1 nephritis by modulating inflammatory cytokines and scatter factors
Authors: Rampino Teresa , Gregorini Marilena , Bedino Giulia , Piotti Giovanni , Gabanti Elisa , Ibatici Adalberto , Sessarego Nadia , Piacenza Cristina , Balenzano Chiara Teresa , Esposito Pasquale , Bosio Francesca , Soccio Grazia , Frassoni Francesco , Dal Canton Antonio
Published: June 2010

MSC (mesenchymal stromal cells) can differentiate into renal adult cells, and have anti-inflammatory and immune-modulating activity. In the present study, we investigated whether MSC have protective/reparative effects in anti-Thy1 disease, an Ab (antibody)-induced mesangiolysis resulting in mesangioproliferative nephritis. We studied five groups of rats: (i) rats injected with anti-Thy1.1 Ab on day 0 (group A); (ii) rats injected with anti-Thy1.1 Ab on day 0+MSC on day 3 (group B); (iii) rats injected with anti-Thy1.1 Ab on day 0+mesangial cells on day 3 (group C); (iv) rats injected with saline on day 0+MSC on day 3 (group D); and (v) rats injected with saline on day 0 (group E). Rats were killed on days 1, 3, 7 and 14. MSC prevented the increase in serum creatinine, proteinuria, glomerular monocyte influx and glomerular histopathological injury. Furthermore, MSC suppressed the release of IL-6 (interleukin-6) and TGF-β (transforming growth factor-β), modulated glomerular PDGF-β (platelet-derived growth factor-β), and reset the scatter factors and their receptors, potentiating HGF (hepatocyte growth factor)/Met and inactivating MSP (macrophage-stimulating protein)/Ron (receptor origin nantaise). Few MSC were found in the kidney. These results indicate that MSC improve anti-Thy 1 disease not by replacing injured cells, but by preventing cytokine-driven inflammation and modulating PDGF-β and the scatter factors, i.e. systems that regulate movement and proliferation of monocytes and mesangial cells.
Effect of collisional quenching on the measurement of ion species mix in neutral beam injectors
Authors: Bharathi P. , Prahlad V.
Published: June 2010

A corona model is used in analyzing the Doppler shifted spectroscopy (DSS) data for estimating the ion species mix and beam species fractions in positive ion based neutral beam injectors. In this model the excited neutral atom is assumed to decay solely by a spontaneous radiative process. However, at the beam energies of 20–60 keV/amu, collisional quenching of the excited neutrals affects these estimations when background pressure exceeds 1 mTorr. We present here a modified corona model that takes into account the effects of collisional quenching. We also describe the results of application of the present model to a typical DSS data obtained in the first phase of operation of the SST-1 neutral beam injector.
On the Cauchy problem for a generalized Degasperis–Procesi equation
Authors: Wu Xinglong , Yin Zhaoyang
Published: June 2010

We mainly study the Cauchy problem of the generalized Degasperis–Procesi equation. First, we establish the local well posedness for the equation. Second, we give the precise blow-up scenario, a conservation law, and prove the equation has smooth solutions which blow up in finite time. Finally, we investigate the blow-up rate for the blow-up solutions.
Trapping single human osteoblast-like cells from a heterogeneous population using a dielectrophoretic microfluidic device
Authors: Thomas Rupert S. W. , Mitchell Peter D. , Oreffo Richard O. C. , Morgan Hywel
Published: June 2010

We describe a system for the isolation, concentration, separation, and recovery of human osteoblast-like cells from a heterogeneous population using dielectrophoretic ring traps. Cells flowing in a microfluidic channel are immobilized inside an electric field cage using negative dielectrophoresis. A planar ring electrode creates a closed trap while repelling surrounding cells. Target cells are identified by fluorescent labeling, and are trapped as they pass across a ring electrode by an automated system. We demonstrate recovery of small populations of human osteoblast-like cells with a purity of 100%, which in turn demonstrates the potential of such a device for cell selection from a heterogeneous population.
Exponential decay of correlation functions in many-electron systems
Authors: Kashima Yohei
Published: June 2010

For a class of tight-binding many-electron models on hypercubic lattices, the equal-time correlation functions at nonzero temperature are proved to decay exponentially in the distance between the center of positions of the electrons and the center of positions of the holes. The decay bounds hold in any space dimension in the thermodynamic limit if the interaction is sufficiently small depending on temperature. The proof is based on the U(1)-invariance property and volume-independent perturbative bounds of the finite dimensional Grassmann integrals formulating the correlation functions.
Liquid dielectrophoresis and surface microfluidics
Authors: Kaler Karan V. I. S. , Prakash Ravi , Chugh Dipankar
Published: June 2010

Liquid dielectrophoresis (L-DEP), when deployed at microscopic scales on top of hydrophobic surfaces, offers novel ways of rapid and automated manipulation of very small amounts of polar aqueous samples for microfluidic applications and development of laboratory-on-a-chip devices. In this article we highlight some of the more recent developments and applications of L-DEP in handling and processing of various types of aqueous samples and reagents of biological relevance including emulsions using such microchip based surface microfluidic (SMF) devices. We highlighted the utility of these devices for on-chip bioassays including nucleic acid analysis. Furthermore, the parallel sample processing capabilities of these SMF devices together with suitable on- or off-chip detection capabilities suggest numerous applications and utility in conducting automated multiplexed assays, a capability much sought after in the high throughput diagnostic and screening assays.
Separation by dielectrophoresis of dormant and nondormant bacterial cells of Mycobacterium smegmatis
Authors: Zhu Ke , Kaprelyants Arseny S. , Salina Elena G. , Markx Gerard H.
Published: June 2010

The dielectrophoretic behavior of active, dead, and dormant Mycobacterium smegmatis bacterial cells was studied. It was found that the 72-h-old dormant cells had a much higher effective particle conductivity (812±10 μS cm−1), almost double that of active cells (560±20 μS cm−1), while that of dead (autoclaved) M. smegmatis cells was the highest (950±15 μS cm−1) overall. It was also found that at 80 kHz, 900 μS cm−1 dead cells were attracted at the edges of interdigitated castellated electrodes by positive dielectrophoresis, but dormant cells were not. Similarly, at 120 kHz, 2 μS cm−1 active cells were attracted and dormant cells were not. Using these findings a dielectrophoresis-based microfluidic separation system was developed in which dead and active cells were collected from a given cell suspension, while dormant cells were eluted.
The influence of SiOx and SiNx passivation on the negative bias stability of Hf–In–Zn–O thin film transistors under illumination
Authors: Park Joon Seok , Kim Tae Sang , Son Kyoung Seok , Lee Kwang-Hee , Maeng Wan-Joo , Kim Hyun-Suk , Kim Eok Su , Park Kyung-Bae , Seon Jong-Baek , Choi Woong , Ryu Myung Kwan , Lee Sang Yoon
Published: June 2010

The stability of hafnium indium zinc oxide thin film transistors under negative bias stress with simultaneous exposure to white light was evaluated. Two different inverted staggered bottom gate devices, each with a silicon oxide and a silicon nitride passivation, were compared. The latter exhibits higher field effect mobility but inferior subthreshold swing, and undergoes more severe shifts in threshold voltage (VT) during negative bias illumination stress. The time evolution of VT fits the stretched exponential equation, which implies that hydrogen incorporation during the nitride growth has generated bulk defects within the semiconductor and/or at the semiconductor/gate dielectric interface.
Hydrothermal synthesis of ordered single-crystalline rutile TiO2 nanorod arrays on different substrates
Authors: Wang Hong-En , Chen Zhenhua , Leung Yu Hang , Luan Chunyan , Liu Chaoping , Tang Yongbing , Yan Ce , Zhang Wenjun , Zapien Juan Antonio , Bello Igor , Lee Shuit-Tong
Published: June 2010

We report the mild hydrothermal synthesis of single-crystalline rutile TiO2 nanorod arrays (NRAs). The method reported here shows great versatility and can be used to grow TiO2 NRAs on a large diversity of substrates including Si, Si/SiO2, sapphire, Si pillars, and fluorine doped tin oxide (FTO)-covered glass. The average diameter and length of the nanorods prepared at typical conditions are ∼60 nm and 400 nm, respectively. Dye-sensitized solar cells assembled with the TiO2 NRAs grown on the FTO-covered glass as photoanode were prepared with a photoconversion efficiency of ∼1.10%.
Wall-bounded turbulent flows at high Reynolds numbers: Recent advances and key issues
Authors: Marusic I. , McKeon B. J. , Monkewitz P. A. , Nagib H. M. , Smits A. J. , Sreenivasan K. R.
Published: June 2010

Wall-bounded turbulent flows at high Reynolds numbers have become an increasingly active area of research in recent years. Many challenges remain in theory, scaling, physical understanding, experimental techniques, and numerical simulations. In this paper we distill the salient advances of recent origin, particularly those that challenge textbook orthodoxy. Some of the outstanding questions, such as the extent of the logarithmic overlap layer, the universality or otherwise of the principal model parameters such as the von Kármán “constant,” the parametrization of roughness effects, and the scaling of mean flow and Reynolds stresses, are highlighted. Research avenues that may provide answers to these questions, notably the improvement of measuring techniques and the construction of new facilities, are identified. We also highlight aspects where differences of opinion persist, with the expectation that this discussion might mark the beginning of their resolution.
Photoexcited charge current for the presence of pure spin current
Authors: Liu Yu , Chen Yonghai , Wang Zhanguo
Published: June 2010

The asymmetric spin distribution in k space caused by the pure spin current (PSC) can introduce a photoexcited charge current (PECC). This provides us a practical scheme for direct detection of PSC. We demonstrate theoretically that the PECC related to the PSC depends sensitively on the wave vector and spin orientation of the carriers, more important, the helicity dependence of this PECC provides us a way to refine it from the helicity independent background current by tuning the polarized laser beams from left to right circular polarization.
Influence of electrode material on the resistive memory switching property of indium gallium zinc oxide thin films
Authors: Chen Min-Chen , Chang Ting-Chang , Tsai Chih-Tsung , Huang Sheng-Yao , Chen Shih-Ching , Hu Chih-Wei , Sze Simon M. , Tsai Ming-Jinn
Published: June 2010

The InGaZnO taken as switching layer in resistive nonvolatile memory is proposed in this paper. The memory cells composed of Ti/InGaZnO/TiN reveal the bipolar switching behavior that keeps stable resistance ratio of 102 with switching responses over 100 cycles. The resistance switching is ascribed to the formation/disruption of conducting filaments upon electrochemical reaction near/at the bias-applied electrode. The influence of electrode material on resistance switching is investigated through Pt/InGaZnO/TiN devices, which perform the unipolar and bipolar behavior as applying bias on Pt and TiN electrode, respectively. Experimental results demonstrate that the switching behavior is selective by the electrode.
Review Article—Dielectrophoresis: Status of the theory, technology, and applications
Authors: Pethig Ronald
Published: June 2010

A review is presented of the present status of the theory, the developed technology and the current applications of dielectrophoresis (DEP). Over the past 10 years around 2000 publications have addressed these three aspects, and current trends suggest that the theory and technology have matured sufficiently for most effort to now be directed towards applying DEP to unmet needs in such areas as biosensors, cell therapeutics, drug discovery, medical diagnostics, microfluidics, nanoassembly, and particle filtration. The dipole approximation to describe the DEP force acting on a particle subjected to a nonuniform electric field has evolved to include multipole contributions, the perturbing effects arising from interactions with other cells and boundary surfaces, and the influence of electrical double-layer polarizations that must be considered for nanoparticles. Theoretical modelling of the electric field gradients generated by different electrode designs has also reached an advanced state. Advances in the technology include the development of sophisticated electrode designs, along with the introduction of new materials (e.g., silicone polymers, dry film resist) and methods for fabricating the electrodes and microfluidics of DEP devices (photo and electron beam lithography, laser ablation, thin film techniques, CMOS technology). Around three-quarters of the 300 or so scientific publications now being published each year on DEP are directed towards practical applications, and this is matched with an increasing number of patent applications. A summary of the US patents granted since January 2005 is given, along with an outline of the small number of perceived industrial applications (e.g., mineral separation, micropolishing, manipulation and dispensing of fluid droplets, manipulation and assembly of micro components). The technology has also advanced sufficiently for DEP to be used as a tool to manipulate nanoparticles (e.g., carbon nanotubes, nano wires, gold and metal oxide nanoparticles) for the fabrication of devices and sensors. Most efforts are now being directed towards biomedical applications, such as the spatial manipulation and selective separation/enrichment of target cells or bacteria, high-throughput molecular screening, biosensors, immunoassays, and the artificial engineering of three-dimensional cell constructs. DEP is able to manipulate and sort cells without the need for biochemical labels or other bioengineered tags, and without contact to any surfaces. This opens up potentially important applications of DEP as a tool to address an unmet need in stem cell research and therapy.
Nonequilibrium carrier distribution in semiconductor photodetectors: Surface leakage channel under illumination
Authors: Yin Hao , Li Tian-xin , Hu Wei-da , Wang Wen-juan , Li Ning , Chen Xiao-shuang , Lu Wei
Published: June 2010

The nonequilibrium carrier distribution in an InGaAs/InP avalanche photodiode under light illumination is obtained by cross-sectional scanning capacitance microscopy combined with numerical simulation. The sheet density of negative surface charge is determined to be 1.85×1010 cm−2 on the native-oxidized InGaAs (110) face. This surface charge is found responsible for the accumulation of minority holes, which leads to an inversion layer at the sidewall surface of device in the absorption region under illumination exceeding 0.1 mW/cm2. The inversion depth increases up to 200 nm along with the enhancement of excitation intensity. This work suggests that a surface leakage channel may form in semiconductor photodetectors through detection light excitation.
Tunneling processes in thin MgO magnetic junctions
Authors: Teixeira J. M. , Ventura J. , Araujo J. P. , Sousa J. B. , Wisniowski P. , Freitas P. P.
Published: June 2010

Magnetic tunnel junctions (MTJs) with MgO barriers are used in a variety of applications, from read heads to novel microwave devices. In this work, we probed the temperature (T) dependence of the electrical transport of sputtered CoFeB/MgO/CoFeB MTJs with different barrier thicknesses (tb=0.75–1.35 nm). We show evidence that spin-polarized direct elastic tunneling is the dominant mechanism determining the T-dependence of the tunnel conductance (G) and magnetoresistance for tb≥0.85 nm. Also, the electronic thermal smearing near the Fermi level plays a key role in G(T). We observe the onset of pinholes for MTJs with 0.75 nm of MgO, with a transition to metallic-like transport.
In situ evolution of stress gradients in Cu films induced by capping layers
Authors: Murray Conal E. , Besser Paul R. , Witt Christian , Toney Michael
Published: June 2010

Depth-dependent stress distributions within copper films possessing capping layers were measured during in situ thermal anneals. Glancing-incidence x-ray diffraction measurements of SiCxNyHz capped Cu films revealed that a strain gradient near the cap/Cu interface, created by constraint imposed by the cap during its deposition process, decreased as the sample temperature increased to 350 °C. Although the increase in sample temperature allowed Cu to approach its equilibrium lattice spacing at the cap deposition temperature and minimize the corresponding stress gradient, both the gradient and concomitant increase in residual bulk stress of the Cu film reappeared after cooling to room temperature.
Phylogenetic analysis using rDNA reveals polyphyly of Oplophoridae (Decapoda:Caridea)
Authors: Chan Tin-Yam , Lei Ho Chee , Li Chi Pang , Chu Ka Hou
Published: June 2010

Molecular phylogenetic analysis on nine of the ten genera in the caridean family Oplophoridae Dana, 1852, as well as 14 other caridean families using mitochondrial 16S and nuclear 18S rRNA genes, does not support the monophyletic status of Oplophoridae. Two disparate groups of oplophorids are revealed, with different morphological characters and ecology. It is proposed that the family Oplophoridae is restricted to the three genera Oplophorus, Systellaspis and Janicella. These three genera tend to be distributed in shallower water than the other oplophorid genera, and can also be distinguished from them by certain morphological characters. They have a thicker integument, superficial cuticular photophores and larger eyes, and the molar process of their mandibles is greatly reduced or bears a deep channel. The family Acanthephyridae Bate, 1888 is resurrected for the other seven genera, which are generally distributed in deeper water and are characterised by red soft integument, no cuticular photophores, smaller eyes and well-developed molar process of the mandibles without a deep channel. The relationships between these two families and other caridean families could not be clearly resolved in this study.
Systematics of the Australian orb-weaving spider genus Demadiana with comments on the generic classification of the Arkyinae (Araneae:Araneidae)
Authors: Framenau Volker W. , Scharff Nikolaj , Harvey Mark S.
Published: June 2010

The orb-weaving spider subfamily Arkyinae L. Koch, 1872 is exclusively found in the Australasian region and its taxonomy and the systematic relationships within and between genera of this subfamily are poorly understood. We here revise the arkyine genus Demadiana Strand, 1929 to include six Australian species, four of which are described as new: Demadiana simplex (Karsch, 1878) (type species), D. carrai, sp. nov., D. cerula (Simon, 1908), comb. nov., D. complicata, sp. nov., D. diabolus, sp. nov., and D. milledgei, sp. nov. A phylogenetic analysis based on an updated araneid morphological data matrix including 57 genera of orb-weaving spiders identified Demadiana as a member of the araneid subfamily Arkyinae. A separate phylogenetic analysis for the genus at the species level showed little resolution within Demadiana, but did identify a monophyletic Demadiana supported by three putative synapomorphies: small unique setal pits with spherical sockets covering the carapace, sternum and the bases of the paturon (chelicerae), an extreme elongation of the trumpet-like aggregate spigots of the posterior lateral spinnerets and a distinct curvature of the embolus. We detail several new generic and species synonymies within Arkyinae. Aerea Urquhart, 1891 (type species Aerea alticephala Urquhart, 1891) and Neoarchemorus Mascord, 1968 (type species N. speechleyi Mascord, 1968) are regarded as junior synonyms of Arkys Walckenaer, 1837 (type species A. lancearius Walckenaer, 1837), resulting in Arkys speechleyi (Mascord, 1968), comb. nov. Aerea magnifica Urquhart, 1893 and Archemorus simsoni Simon, 1893 are regarded as junior synonyms of Aerea alticephala Urquhart, 1891, and Arkys nitidiceps Simon, 1908 is proposed as a junior synonym of Arkys walckenaeri Simon, 1879.
Expert judgments about transient climate response to alternative future trajectories of radiative forcing
Authors: Zickfeld Kirsten , Morgan M. Granger , Frame David J. , Keith David W.
Published: June 2010

There is uncertainty about the response of the climate system to future trajectories of radiative forcing. To quantify this uncertainty we conducted face-to-face interviews with 14 leading climate scientists, using formal methods of expert elicitation. We structured the interviews around three scenarios of radiative forcing stabilizing at different levels. All experts ranked “cloud radiative feedbacks” as contributing most to their uncertainty about future global mean temperature change, irrespective of the specified level of radiative forcing. The experts disagreed about the relative contribution of other physical processes to their uncertainty about future temperature change. For a forcing trajectory that stabilized at 7 Wm
-2
in 2200, 13 of the 14 experts judged the probability that the climate system would undergo, or be irrevocably committed to, a “basic state change” as ≥0.5. The width and median values of the probability distributions elicited from the different experts for future global mean temperature change under the specified forcing trajectories vary considerably. Even for a moderate increase in forcing by the year 2050, the medians of the elicited distributions of temperature change relative to 2000 range from 0.8–1.8 °C, and some of the interquartile ranges do not overlap. Ten of the 14 experts estimated that the probability that equilibrium climate sensitivity exceeds 4.5 °C is > 0.17, our interpretation of the upper limit of the “likely” range given by the Intergovernmental Panel on Climate Change. Finally, most experts anticipated that over the next 20 years research will be able to achieve only modest reductions in their degree of uncertainty.
Overexpression of ST6GalNAcV, a ganglioside-specific α2,6-sialyltransferase, inhibits glioma growth in vivo
Authors: Kroes Roger A. , He Huan , Emmett Mark R. , Nilsson Carol L. , Leach Franklin E. , Amster I. Jonathan , Marshall Alan G. , Moskal Joseph R.
Published: June 2010

Aberrant cell-surface glycosylation patterns are present on virtually all tumors and have been linked to tumor progression, metastasis, and invasivity. We have shown that expressing a normally quiescent, glycoprotein-specific α2,6-sialyltransferase (ST6Gal1) gene in gliomas inhibited invasivity in vitro and tumor formation in vivo. To identify other glycogene targets with therapeutic potential, we created a focused 45-mer oligonucleotide microarray platform representing all of the cloned human glycotranscriptome and examined the glycogene expression profiles of 10 normal human brain specimens, 10 malignant gliomas, and 7 human glioma cell lines. Among the many significant changes in glycogene expression observed, of particular interest was the observation that an additional α2,6-sialyltransferase, ST6 (α-
N
-acetyl-neuraminyl-2,3-β-galactosyl-1,3)-
N
-acetylgalactosaminide α2,6-sialyltransferase 5 (ST6GalNAcV), was expressed at very low levels in all glioma and glioma cell lines examined compared with normal brain. ST6GalNAcV catalyzes the formation of the terminal α2,6-sialic acid linkages on gangliosides. Stable transfection of ST6GalNAcV into U373MG glioma cells produced (
i
) no change in α2,6-linked sialic acid-containing glycoproteins, (
ii
) increased expression of GM2α and GM3 gangliosides and decreased expression of GM1b, Gb3, and Gb4, (
iii
) marked inhibition of in vitro invasivity, (
iv
) modified cellular adhesion to fibronectin and laminin, (
v
) increased adhesion-mediated protein tyrosine phosphorylation of HSPA8, and (
vi
) inhibition of tumor growth in vivo. These results strongly suggest that modulation of the synthesis of specific glioma cell-surface glycosphingolipids alters invasivity in a manner that may have significant therapeutic potential.
Indoor fungal composition is geographically patterned and more diverse in temperate zones than in the tropics
Authors: Amend Anthony S. , Seifert Keith A. , Samson Robert , Bruns Thomas D.
Published: June 2010

Fungi are ubiquitous components of indoor human environments, where most contact between humans and microbes occurs. The majority of these organisms apparently play a neutral role, but some are detrimental to human lifestyles and health. Recent studies that used culture-independent sampling methods demonstrated a high diversity of indoor fungi distinct from that of outdoor environments. Others have shown temporal fluctuations of fungal assemblages in human environments and modest correlations with human activity, but global-scale patterns have not been examined, despite the manifest significance of biogeography in other microbial systems. Here we present a global survey of fungi from indoor environments (
n
= 72), using both taxonomic and phylogeny-informative molecular markers to determine whether global or local indoor factors determine indoor fungal composition. Contrary to common ecological patterns, we show that fungal diversity is significantly higher in temperate zones than in the tropics, with distance from the equator being the best predictor of phylogenetic community similarity. Fungal composition is significantly auto-correlated at the national and hemispheric spatial scales. Remarkably, building function has no significant effect on indoor fungal composition, despite stark contrasts between architecture and materials of some buildings in close proximity. Distribution of individual taxa is significantly range- and latitude-limited compared with a null model of randomized distribution. Our results suggest that factors driving fungal composition are primarily global rather than mediated by building design or function.
T cell-engaging BiTE antibodies specific for EGFR potently eliminate KRAS- and BRAF-mutated colorectal cancer cells
Authors: Lutterbuese Ralf , Raum Tobias , Kischel Roman , Hoffmann Patrick , Mangold Susanne , Rattel Benno , Friedrich Matthias , Thomas Oliver , Lorenczewski Grit , Rau Doris , Schaller Evelyne , Herrmann Ines , Wolf Andreas , Urbig Thomas , Baeuerle Patrick A. , Kufer Peter
Published: June 2010

Epidermal growth factor receptor (EGFR)-specific monoclonal antibodies predominantly inhibit colorectal cancer (CRC) growth by interfering with receptor signaling. Recent analyses have shown that patients with CRC with mutated KRAS and BRAF oncogenes do not profit from treatment with such antibodies. Here we have used the binding domains of cetuximab and pantitumumab for constructing T cell-engaging BiTE antibodies. Both EGFR-specific BiTE antibodies mediated potent redirected lysis of KRAS- and BRAF-mutated CRC lines by human T cells at subpicomolar concentrations. The cetuximab-based BiTE antibody also prevented at very low doses growth of tumors from KRAS- and BRAF-mutated human CRC xenografts, whereas cetuximab was not effective. In nonhuman primates, no significant adverse events were observed during treatment for 3 wk at BiTE serum concentrations inducing, within 1 d, complete lysis of EGFR-overexpressing cancer cells. EGFR-specific BiTE antibodies may have potential to treat CRC that does not respond to conventional antibodies.
Structural basis for the allosteric control of the global transcription factor NtcA by the nitrogen starvation signal 2-oxoglutarate
Authors: Zhao Meng-Xi , Jiang Yong-Liang , He Yong-Xing , Chen Yi-Fei , Teng Yan-Bin , Chen Yuxing , Zhang Cheng-Cai , Zhou Cong-Zhao
Published: June 2010

2-oxogluatarate (2-OG), a metabolite of the highly conserved Krebs cycle, not only plays a critical role in metabolism, but also constitutes a signaling molecule in a variety of organisms ranging from bacteria to plants and animals. In cyanobacteria, the accumulation of 2-OG constitutes the signal of nitrogen starvation and NtcA, a global transcription factor, has been proposed as a putative receptor for 2-OG. Here we present three crystal structures of NtcA from the cyanobacterium
Anabaena
: the apoform, and two ligand-bound forms in complex with either 2-OG or its analogue 2,2-difluoropentanedioic acid. All structures assemble as homodimers, with each subunit composed of an N-terminal effector-binding domain and a C-terminal DNA-binding domain connected by a long helix (C-helix). The 2-OG binds to the effector-binding domain at a pocket similar to that used by cAMP in catabolite activator protein, but with a different pattern. Comparative structural analysis reveals a putative signal transmission route upon 2-OG binding. A tighter coiled-coil conformation of the two C-helices induced by 2-OG is crucial to maintain the proper distance between the two F-helices for DNA recognition. Whereas catabolite activator protein adopts a transition from off-to-on state upon cAMP binding, our structural analysis explains well why NtcA can bind to DNA even in its apoform, and how 2-OG just enhances the DNA-binding activity of NtcA. These findings provided the structural insights into the function of a global transcription factor regulated by 2-OG, a metabolite standing at a crossroad between carbon and nitrogen metabolisms.
Ultrahigh-resolution microstructural diffusion tensor imaging reveals perforant path degradation in aged humans in vivo
Authors: Yassa Michael A. , Muftuler L. Tugan , Stark Craig E. L.
Published: June 2010

The perforant path (PP) undergoes synaptic changes in the course of aging and dementia. Previous studies attempting to assess the integrity of the PP in humans using diffusion tensor imaging (DTI) were limited by low resolution and the inability to identify PP fibers specifically. Here we present an application of DTI at ultrahigh submillimeter resolution that has allowed us to successfully identify diffusion signals unique to the PP and compare the intensity of these signals in a sample of young adults and older adults. We report direct evidence of age-related PP degradation in humans in vivo. We find no evidence of such loss in a control pathway, the alveus, suggesting that these findings are not evidence for a global decline. We also find no evidence for specific entorhinal gray matter atrophy. The extent of PP degradation correlated with performance on a word-list learning task sensitive to hippocampal deficits. We also show evidence for gray matter diffusion signals consistent with pyramidal dendrite orientation in the hippocampus and cerebral cortex. Ultrahigh-resolution microstructural DTI is a unique biomarker that can be used in combination with traditional structural and functional neuroimaging methods to enhance detection of Alzheimer disease in its earliest stages, test the effectiveness of new therapies, and monitor disease progression.
Agonist of growth hormone-releasing hormone as a potential effector for survival and proliferation of pancreatic islets
Authors: Ludwig Barbara , Ziegler Christian G. , Schally Andrew V. , Richter Claudius , Steffen Anja , Jabs Normund , Funk Richard H. , Brendel Mathias D. , Block Norman L. , Ehrhart-Bornstein Monika , Bornstein Stefan R.
Published: June 2010

Therapeutic strategies for transplantation of pancreatic islet cells are urgently needed to expand β-cell mass by stimulating islet cell proliferation and/or prolonging islet cell survival. Control of the islets by different growth factors provides a potential venue for augmenting β-cell mass. In the present study, we show the expression of the biologically active splice variant-1 (SV-1) of growth hormone-releasing hormone (GHRH) receptor in rat insulinoma (INS-1) cells as well as in rat and human pancreatic islets. In studies in vitro of INS-1 cells, the GHRH agonist JI-36 caused a significant increase in cell proliferation and a reduction of cell apoptosis. JI-36 increased islet size and glucose-stimulated insulin secretion in isolated rat islets after 48–72 h. At the ultrastructural level, INS-1 cells treated with agonist JI-36 revealed a metabolic active stimulation state with increased cytoplasm. Coincubation with the GHRH antagonist MIA-602 reversed the actions of the agonist JI-36, indicating the specificity of this agonist. In vivo, the function of pancreatic islets was assessed by transplantation of rat islets under the kidney capsule of streptozotocin-induced diabetic non-obese diabetic-severe combined immunodeficiency (NOD-SCID) mice. Islets treated with GHRH agonist JI-36 were able to achieve normoglycemia earlier and more consistently than untreated islets. Furthermore, in contrast to diabetic animals transplanted with untreated islets, insulin response to an i.p. glucose tolerance test (IPGTT) in animals receiving islets treated with agonist Jl-36 was comparable to that of normal healthy mice. In conclusion, our study provides evidence that agonists of GHRH represent a promising pharmacological therapy aimed at promoting islet graft growth and proliferation in diabetic patients.