bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of biogas digestion on the environmental impact and energy balances in organic cropping systems using the life-cycle assessment methodology
Authors: Michel Jens , Weiske Achim , Möller Kurt
Published: March 2010

A life-cycle assessment (LCA) was carried out to compare the environmental performance of different organic cropping systems with and without digestion of slurry and crop residues. The aims of the present study are: (1) to compare the environmental performance of organic farming dairy systems with the currently prevalent animal housing systems [solid farmyard manure (FYM) versus liquid slurry] as the main reference systems; (2) to analyze the effect of the implementation of a biogas digestion system on the consumption of fossil fuels and production of electrical energy; (3) to quantify the effects of the implementation of a biogas digestion system on the environment; and (4) to compare the obtained net energy yields with other means of obtaining energy by using the farmland area. The considered impact categories are greenhouse gas (GHG) balances, acidification, eutrophication and groundwater pollution. LCA results indicated that total emissions in systems based on FYM are much higher than in liquid slurry systems for most of the considered impact categories. The benefits of digestion of stable wastes in comparison with the reference system without digestion are mainly (1) the net reduction of the emissions of GHG and (2) energy recovery from produced biogas, while the disadvantages can be higher emissions of NH3 after spreading. The effects of additional biogas digestion of biomass such as crop residues (e.g., straw of peas and cereals) and cover crops are: (1) an optimization of the N-cycle and therewith higher yields; (2) higher energy production per unit arable land; (3) a further reduction of the GHG balance; but (4) higher N-related environmental burdens like eutrophication and acidification. The offsets of fossil fuel emissions were the largest GHG sink in most of the biogas digestion systems. The inclusion of a biogas plant into organic cropping systems and the use of the available wastes for production of energy largely increased the overall productivity of the farming system and matched very well the basic principles of organic farming such as a high self-sufficiency of the cropping system and reducing as much as possible the environmental impact of farming.
Narcissism and Perceived Inequity in Attractiveness in Romantic Relationships
Authors: Rohmann Elke , Bierhoff Hans-Werner , Schmohr Martina
Published: March 2010

In three studies of romantic relationships (N = 253, N = 81, and N = 98) the hypothesis was tested that high narcissists, relative to low narcissists, distort the assessment of equity in attractiveness. Narcissism was measured by the Narcissistic Personality Inventory. In Study 1 the hypothesis was confirmed. In Study 2 it was shown that although narcissism correlated significantly with self-esteem, it was the unique variance in narcissism which predicted the tendency to feel underbenefited in respect to attractiveness. Finally in Study 3, dyadic data were analyzed on the basis of the Actor-Partner Interdependence Model. The data of 49 couples who lived together were included. The dyadic analysis indicated that actor narcissism exerted the expected influence on perceived inequity in attractiveness, whereas partner narcissism explained no additional variance. High narcissists felt more underbenefited than low narcissists. The analysis of dyadic data in Study 3 indicates that the link between narcissism and equity in attractiveness turns out to be an intrapersonal phenomenon because only actor narcissism, not partner narcissism, is significantly correlated with perceived inequity. In addition, partial intraclass correlations revealed that if one partner tended to feel underbenefited, the other partner tended to feel overbenefited. The results are explained on the basis of the agentic model of narcissism. All three studies consistently revealed a gender effect indicating that women felt more underbenefited than men in terms of attractiveness.
An Application of Affective Events Theory to Workplace Bullying
Authors: Glasø Lars , Vie Tina Løkke , Holmdal Gry Rotnes , Einarsen Ståle
Published: March 2010

Within the framework of Affective Events Theory (AET), this study examines emotional experiences as a potential mediator between exposure to bullying and job satisfaction and intention to leave, respectively. We also investigate to what extent trait anxiety and trait anger moderate the relationships between these variables. The results show that the relationships between bullying and both job satisfaction and intentions to leave are partly mediated by the targets’ emotional experiences. Trait anxiety moderates the relationship between exposure to bullying and the targets’ negative emotions. Trait anxiety and trait anger did not moderate the relationship between bullying and the outcomes. The results support the validity of AET, while simultaneously indicating exposure to bullying as a strong stressor in its own right.
Strong velocity weakening and powder lubrication of simulated carbonate faults at seismic slip rates
Authors: Han Raehee , Hirose Takehiro , Shimamoto Toshihiko
Published: March 2010

High‐velocity friction tests were conducted on solid and hollow cylinders of Carrara (calcite) marble, dolomite marble, silicate‐bearing calcite marble, and calcite gouge to investigate the strength of carbonate faults during seismic slip. The experiments, performed at normal stresses of 0.6–14.7 MPa, slip rates of 0.03–1.60 m/s, and room temperature in a rotary‐shear friction testing machine, yielded an extraordinarily low steady state friction coefficient (<0.1) at slip rates of ∼1.1–1.2 m/s. The slip‐weakening distance of 4–28 m became shorter at higher normal stress or frictional work rate. Strong velocity weakening was observed not only in steady state but also in nonsteady state friction, while the slip rate was changing; thus slip deceleration was accompanied by fault strength recovery. Large, rapid temperature rises in narrow shear localization zones (less than a few micrometers) induced carbonate decomposition, such as the breakdown of calcite into aggregates of CaO nanograins and CO2 in Carrara marble. Scanning electron microscope observation revealed that the shear localization zone in the highly porous decomposition product was a layer of scattered small grains (mostly <1 μm in diameter). These microstructures and the measured high permeability (∼10−14 m2) of the decomposed marble indicate that the dominant weakening mechanism in our experiments was possibly powder lubrication. Powder rheology at high slip rates is not yet well understood, but the frictional behavior of nanograins appears to be strongly velocity dependent. If decarbonation occurs during seismic slip in natural carbonate faults, powder lubrication may make the faults slippery even under fluid‐drained conditions.
Insights into active tectonics of eastern Taiwan from analyses of geodetic and geologic data
Authors: Huang Wen‐Jeng , Johnson Kaj M. , Fukuda Jun'ichi , Yu Shui‐Beih
Published: March 2010

About 50 mm/yr of convergence between the Philippine Sea and Eurasian plates is absorbed in eastern Taiwan, and it remains unclear how the convergence is partitioned among active faults. The Longitudinal Valley fault (LVF), the most seismically active fault in eastern Taiwan, creeps at the surface in the south and not in the north; however, it is unclear how much of the fault is locked or creeping at depth. To address these problems, we model Holocene and interseismic deformation of elastic lithospheric blocks moving over a viscoelastic asthenosphere in eastern Taiwan. Through a fully probabilistic scheme, we invert GPS, interferometric synthetic aperture radar, creepmeter, and Holocene marine terrace data for block motions, fault slip rates, and distribution of interseismic creep. The data are explained with four blocks separated by three faults, Central Range fault, LVF, and an offshore fault. The model explains the essential features of interseismic and Holocene deformation. We find that 35–55 mm/yr of slip on the offshore fault is necessary to fit marine terrace uplift rates, which is a larger fraction of the plate convergence than previously recognized. The LVF has a Holocene slip rate of 20–30 mm/yr with approximately equal magnitudes of reverse‐slip and left‐lateral strike‐slip components. Only about half of the surface area of the Longitudinal Valley fault appears to be locked. The southern segment of the LVF creeps at a rate of 5–28 mm/yr down to a depth of 15–20 km, while the northern segment is locked from the surface to a depth of 20 km.
Wind‐generated eddy characteristics in the lee of the island of Hawaii
Authors: Yoshida Sachiko , Qiu Bo , Hacker Peter
Published: March 2010

Weekly satellite sea surface height (SSH) anomaly data are used to clarify the mesoscale eddy characteristics in the lee of the island of Hawaii, the largest island in the Hawaiian Island chain. The lee eddy variability can be separated into two geographical regions. In the immediate lee southwest of Hawaii (Region E), eddy signals have a predominant 60 day period and a short life‐span, whereas in the region along 19°N west of ∼160°W (Region W), the eddy variability is dominated by 100 day signals and extends over a broad region. By applying a linear Ekman pumping model forced by the weekly QuikSCAT wind data, we find that the observed 60 day eddy signals originate in the southwest corner of Hawaii and are induced by the local 60 day wind stress curl variability associated with the blocking of the trade wind by the island of Hawaii. The relationship between the wind forcing and the observed SSH signals demonstrates the role of the ocean as an integrator that responds more effectively to the low‐frequency synoptic atmospheric forcing (∼60 days) than to the higher‐frequency forcing (∼30 days). Since the large‐amplitude 60 day SSH anomalies take 1–2 weeks to fully develop, it is possible that real‐time observed wind stress data can be used for the prediction of these anomalies. In contrast to the wind‐induced 60 day eddy signals in the lee of the island of Hawaii, the 100 day eddy signals in Region W are likely generated by the instability of the sheared North Equatorial Current and Hawaii Lee Countercurrent.
An assessment of surface heat fluxes from J‐OFURO2 at the KEO and JKEO sites
Authors: Tomita Hiroyuki , Kubota Masahisa , Cronin Meghan F. , Iwasaki Shinsuke , Konda Masanori , Ichikawa Hiroshi
Published: March 2010

The daily mean air‐sea heat fluxes over the global oceans have been developed as the version 2 of Japanese Ocean Flux data sets with use of Remote sensing Observations (J‐OFURO2). Net heat flux is available from 1988 to 2006, and the turbulent heat flux is available from 1988 to 2007. To assess the accuracy of the J‐OFURO2 product over the Kuroshio Extension region, air‐sea heat fluxes and related state variables were compared with independent in situ observations from the Kuroshio Extension Observatory (KEO) and JAMSTEC KEO (JKEO) surface moorings. Although seasonal biases were found, these tended to cancel out over the total period, resulting in a total bias and RMS in J‐OFURO2 net heat fluxes of 8.6 and 56.8 W/m2, respectively. Comparisons with other global air‐sea heat flux products from numerical weather prediction, i.e., the National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis (NRA1), the NCEP/Department of Energy reanalysis (NRA2), and satellite observations, i.e., Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite data and merged product, i.e., Objectively Analyzed Air‐Sea Fluxes were also conducted at the KEO and JKEO sites. Comparison results show that the total and seasonal biases are smallest compared with other products, and J‐OFURO2 air‐sea heat fluxes are best data set for air‐sea interaction study over the Kuroshio Extension region.
Enhancing RNAi efficiency by inserting Nuclear factor-κB binding sequence into SiRNA expression cassette
Authors: Yi Jianzhong , Liu Chenqian
Published: March 2010

RNAi based applications have been widely used to manipulate cellular phenotypes, analyze gene function and as a promising molecular therapy, however, there are rare reports in how to target the SiRNA expression constructs from the cytoplasm to nucleus. In this study, we inserted NF-κB binding sequence into the SiRNA expression cassette to enhance RNAi efficiency, tested this propose by use of tRNAval and human H1 promoters, and eGFP and luciferase as reporter protein. The results showed that inserting NF-κB binding sequence at the 3’-terminal of the SiRNA expression construct could enhance RNAi efficiency.
Inequivalent solutions for Dirac spin-12 particles under conservation of parity I
Authors: Liu C. J.
Published: March 2010

Inequivalent invariance constraints upon solutions for Dirac spin-12 particles under conservation of space inversion, time reversal, and charge conjugation have been established, respectively, from standard representation. For space inversion we explicitly show that the wave functions for zero mass neutrinos satisfy only one constraint. For free particles we show that the conventional plane wave solutions as well as Foldy–Wouthuysen representation conditionally comply with the inversion constraints. As a result, only two positive energy solutions and two negative energy solutions can be established. Instead, by law of conservation of parity one shall obtain four linearly independent plane wave solutions which hold not only for positive energies but also for negative energies. We explicitly point out why conventional approach fails to obtain such result. In contrast with free particles one expects intuitively that in a Coulomb field, one can establish twice as many as conventional solutions. Indeed, one shall find easily from inversion constraints that additional linearly independent degenerate bound states have to be established. We present the explicit result.
Hexagonal SiGe quantum dots and nanorings on Si(110)
Authors: Lee C.-H. , Liu C. W. , Chang H.-T. , Lee S. W.
Published: March 2010

The hexagonal shapes of Si0.13Ge0.87 quantum dots (QDs) and rings on Si(110) reflect the lattice symmetry of the top two Si layers on Si, which is different from that on Si(100). The formation time of nanorings on Si(110) is much longer than that on Si(100). This is probably due to the slow diffusion of Ge and Si on Si(110) substrate. Based on both transmission electron microscopy and Raman spectroscopy, the formation of SiGe nanorings can be attributed to Ge outdiffusion from the top of the central SiGe QDs during in situ annealing. Moreover, the Si cap layer is essential for nanorings formation. The uncapped QDs cannot transform into rings even after a long time annealing.
Selective absorption enhancement in organic solar cells using light incoupling layers
Authors: Meiss Jan , Furno Mauro , Pfuetzner Steffen , Leo Karl , Riede Moritz
Published: March 2010

We show that capping layers of tris-(8-hydroxy-quinolinato)-aluminum Alq3 enable increased absorption and photocurrent in organic solar cells (OSCs) when using transparent metal films as top electrodes. Furthermore, by varying the capping layer thickness, the optical field in the OSC is tuned for selective wavelengths, opening a possibility of influencing the external quantum efficiency for specific absorber materials. It is described how a second maximum of the optical field intensity can be utilized, which is a concept significant for tandem solar cells. Indium tin oxide (ITO)-free OSCs are presented which show the influence of capping layer on efficiency, saturation, fill factor, and open-circuit voltage, with numerical calculations supporting the experimental evidence of layer-selective enhancement.
A nonsequential turbulent mixing process
Authors: Duplat J. , Innocenti C. , Villermaux E.
Published: March 2010

We study the relaxation of an initially segregated scalar mixture in a randomly stirred medium, aiming at describing the overall concentration distribution of the mixture, its shape, and its rate of deformation as it evolves toward uniformity. An ever dispersing mixture is realized by releasing a plume of scalar in a large scale, sustained turbulent medium on the axis and in the far field of a turbulent jet. The fluid particles constitutive of the plume are soon resolved into a set of stretched sheets whose rates of diffusive smoothing build up the overall mixture concentration distribution. The randomness of the particle’s net elongation at a given instant of time induces a distribution of the mixing time from which molecular diffusion becomes effective in erasing the concentration differences. This ingredient is shown to rule the composition of this dispersing mixture, providing a detailed analytic description of the overall concentration distribution. It compares favorably with experiments using three different passive scalars, suggesting that the mixture composition results from a nonsequential, one-step lengthening process distributed among the sheets.
Inertial particle resuspension in a turbulent, square duct flow
Authors: Yao J. , Fairweather M.
Published: March 2010

Particle resuspension in a turbulent, square duct flow is studied using large eddy simulation combined with Lagrangian particle tracking under conditions of one-way coupling, with the particle equation of motion solved with the Stokes drag, lift, buoyancy, and gravitational force terms. Here, resuspension is taken to mean the movement of particles in close proximity to the duct walls back in to the mainstream of the flow. The flow considered has a bulk Re=250 k, with four particle sizes ranging from 5 to 500 μm examined. The results demonstrate that turbulence-driven secondary flows within the duct play an important role in the resuspension process. In the vertical direction, resuspension is promoted by the drag force arising from the secondary flows, which is balanced by the gravitational force, with this effect increasing with decreasing particle size. In the horizontal direction, particle resuspension is promoted by the particle’s inertial force, with this effect increasing with increasing particle size. For resuspension in both directions, the drag force dominates small particle resuspension, while for large particles the lift force is also a contributing factor. In the horizontal direction, the effect of the lift force varies with the direction of the secondary flow and becomes more significant when a particle is large or close to the duct wall. The influence of the lift force is also larger in the vertical than in the horizontal direction due to the effects of gravity.
The properties of dimers confined between two charged plates
Authors: Hatlo Marius M. , Bohinc Klemen , Lue Leo
Published: March 2010

We consider two like-charged planar surfaces immersed in solution of oppositely charged dimer counterions with a bond length l. To analyze this system, we extend and employ a self-consistent field theory that has been shown to be accurate from the weak to the intermediate through to the strong coupling regimes. In the limit of very short dimers, the results converge to the results for pointlike divalent ions. Near the surfaces, the dimers lie parallel to the charged plates. In the intermediate coupling regime, the dimers are aligned perpendicularly to the surface when they are a distance l from a surface. In the weak coupling regime, the interactions are only repulsive. At slightly higher couplings, there is a minimum in the variation of the free energy with distance at approximately the bond length of the dimers, which arises from bridging conformations of the dimers. In the intermediate coupling regime, an additional minimum in the free energy is observed at much smaller distances, which is due to the correlations between the dimers. For large dimer bond lengths, this minimum is metastable with respect to the previous minimum. However, as the bond length decreases, this minimum becomes the stable, while the minimum associated with the dimer bond length becomes metastable and eventually disappears. For shorter dimer bond length the attractive interaction is the result of correlations between counterions and charges on the surfaces. We find that dimers can mediate attractive interaction between like-charged surfaces in the intermediate coupling regime. The analysis of orientations confirms the bridging mechanism for sufficiently long dimers, whereas at high electrostatic couplings charge correlations contribute to the attraction.
Gain and noise of high-performance long wavelength superlattice infrared detectors
Authors: Soibel Alexander , Ting David Z.-Y. , Hill Cory J. , Lee Mike , Nguyen Jean , Keo Sam A. , Mumolo Jason M. , Gunapala Sarath D.
Published: March 2010

We experimentally investigate the noise and gain of high-performance long-wavelength superlattice (SL) infrared photodetectors. We compare a recently demonstrated SL heterodiode, which exhibits an electrical gain much larger than unity, with a SL photodetector without gain to show that the electrical gain in these devices originates from the device structure rather than from the SL absorber. We directly measure the noise spectra of a high performance SL, and show that 1/f noise is not intrinsically present in these structures. However, we find that a very large extraneous frequency-dependent noise can be generated by side-wall leakage currents. Analysis of the noise and gain indicate that the exact dependence of the shot noise on the dark current in these SL heterodiodes can be different from that in the diffusion-limited diode homojunction.
Strain-driven alignment of In nanocrystals on InGaAs quantum dot arrays and coupled plasmon-quantum dot emission
Authors: Urbańczyk A. , Hamhuis G. J. , Nötzel R.
Published: March 2010

We report the alignment of In nanocrystals on top of linear InGaAs quantum dot (QD) arrays formed by self-organized anisotropic strain engineering on GaAs (100) by molecular beam epitaxy. The alignment is independent of a thin GaAs cap layer on the QDs revealing its origin is due to local strain recognition. This enables nanometer-scale precise lateral and vertical site registration between the QDs and the In nanocrystals and arrays in a single self-organizing formation process. The plasmon resonance of the In nanocrystals overlaps with the high-energy side of the QD emission leading to clear modification of the QD emission spectrum.
Transmission efficiency of surface plasmon polaritons across gaps in gold waveguides
Authors: Flynn Richard A. , Vurgaftman Igor , Bussmann Konrad , Simpkins B. S. , Kim Chul Soo , Long James P.
Published: March 2010

A far-field microscopy approach is introduced that measures the transmittance of surface plasmon polaritons across gaps in plasmonic waveguides. Local plasmon intensity is monitored through radiation scattered from discontinuities placed before and after the gap. An unusually broad range of gap sizes, 30 nm to 16 μm, is reported for optically thick, 5 μm wide Au stripe-waveguides excited at 860 nm wavelength. Transmittances approach 100% for a 30 nm gap and remain as high as 50% for a 1 μm gap. Finite-element analysis yields transmittances in agreement with experiment and finds gap losses are dominated by radiation scattered into the substrate and air.
Temperature dependent nucleation and annihilation of individual magnetic vortices
Authors: Mihajlović G. , Patrick M. S. , Pearson J. E. , Novosad V. , Bader S. D. , Field M. , Sullivan G. J. , Hoffmann A.
Published: March 2010

We studied the temperature dependence of the magnetization reversal in individual submicron permalloy disks with micro-Hall and bend-resistance magnetometry. The nucleation field exhibits a nonmonotonic dependence with positive and negative slopes at low and high temperatures, respectively, while the annihilation field monotonically decreases with increasing temperature, but with distinctly different slopes at low and high temperatures. Our analysis suggests that at low temperatures vortex nucleation and annihilation proceeds via thermal activation over an energy barrier, while at high temperatures they are governed by a temperature dependence of the saturation magnetization.
Plasmon stimulated emission in arrays of bimetallic structures coated with dye-doped dielectric
Authors: Krishnan A. , Frisbie S. P. , Grave de Peralta L. , Bernussi A. A.
Published: March 2010

We report results on the propagation modes in plasmonic structures incorporating a gain medium using Fourier-plane leakage radiation microscopy. We demonstrate that high contrast images and detailed mode propagation information can be obtained with arrays of dielectric loaded surface plasmon waveguides. Clear interference effects were observed in the Fourier-plane images corresponding to arrays of bimetallic stripes coated with a gain material. This indicates coherent superposition of leaked fluorescence from coupled adjacent waveguides as a result of plasmon stimulated emission.
Educational Inequality under China's Rural–Urban Divide: The Hukou System and Return to Education
Authors: Fu Qiang , Ren Qiang
Published: March 2010

We use microsample data from the 2005 (1%) National Population Sample Survey in southeast China and examine the relationship between the effect of hukou status on income and return to education under China's rural–urban divide. For labor-market return we find that: (1) the influence of hukou status is deeply rooted in an indivdual's other key features (occupation, years of schooling, and working location) in the labor market, and (2) hukou status affects labor-market return primarily through its influence on people's return to education. Assisted by spline regression models, we find that the gap of return to education among people with different hukou status increases as years of schooling decrease, and reaches its peak in primary education. The data overwhelmingly suggest that individuals' human capital was largely determined by the place (rural versus urban) where they were born and received their compulsory education, which highlights the role of China's rural–urban divide in shaping people's labor-market return.
Early childhood service development and intersectoral collaboration in rural Australia
Authors: Johns Susan
Published: March 2010

There is a paucity of research into the development of intersectoral collaborations designed to support early childhood development in rural communities. Drawing on findings from a qualitative study conducted in three small rural communities in Tasmania, this paper will examine community-based intersectoral collaborations involving government and non-government organisations from the health and allied health, education and community service sectors. The paper analyses the process of developing intersectoral collaborations from the perspective of early childhood health and wellbeing. The specific focus is on collaborations that build family and community capacity. Findings indicate that three groups of factors operate interdependently to influence collaborations: social capital, leadership and environmental factors. Each community has different leadership sources, structures and processes, shaped by levels of community social capital, and by environmental factors such as policy and resources. Effective models of early childhood development require strong local and external leadership. Rural communities that are able to identify and harness the skills, knowledge and resources of internal and external leaders are well positioned to take greater ownership of their own health and wellbeing. The paper provides guidelines for developing and enhancing the capacity of rural communities at different stages of collaborative readiness.
Induction of TGF-β1 and TGF-β1–dependent predominant Th17 differentiation by group A streptococcal infection
Authors: Wang Beinan , Dileepan Thamotharampillai , Briscoe Sarah , Hyland Kendra A. , Kang Johnthomas , Khoruts Alexander , Cleary P. Patrick
Published: March 2010

Recurrent group AStreptococcus(GAS) tonsillitis and associated autoimmune diseases indicate that the immune response to this organism can be ineffective and pathological. TGF-β1 is recognized as an essential signal for generation of regulatory T cells (Tregs) and T helper (Th) 17 cells. Here, the impact of TGF-β1 induction on the T-cell response in mouse nasal-associated lymphoid tissue (NALT) following intranasal (i.n.) infections is investigated. ELISA and TGF-β1-luciferase reporter assays indicated that persistent infection of mouse NALT with GAS sets the stage for TGF-β1 and IL-6 production, signals required for promotion of a Th17 immune response. As predicted, IL-17, the Th17 signature cytokine, was induced in a TGF-β1 signaling-dependent manner in single-cell suspensions of both human tonsils and NALT. Intracellular cytokine staining and flow cytometry demonstrated that CD4+IL-17+T cells are the dominant T cells induced in NALT by i.n. infections. Moreover, naive mice acquired the potential to clear GAS by adoptive transfer of CD4+T cells from immunized IL-17A+/+mice but not cells from IL-17A−/−mice. These experiments link specific induction of TGF-β1 by a bacterial infection to an in vivo Th17 immune response and show that this cellular response is sufficient for protection against GAS. The association of a Th17 response with GAS infection reveals a potential mechanism for destructive autoimmune responses in humans.
Ordering human CD34+CD10−CD19+pre/pro-B-cell and CD19−common lymphoid progenitor stages in two pro-B-cell development pathways
Authors: Sanz Eva , Muñoz-A. Norman , Monserrat Jorge , Van-Den-Rym Ana , Escoll Pedro , Ranz Ismael , Álvarez-Mon Melchor , de-la-Hera Antonio
Published: March 2010

Studies here respond to two long-standing questions: Are human “pre/pro-B” CD34+CD10−CD19+and “common lymphoid progenitor (CLP)/early-B” CD34+CD10+CD19−alternate precursors to “pro-B” CD34+CD19+CD10+cells, and do the pro-B cells that arise from these progenitors belong to the same or distinct B-cell development pathways? Using flow cytometry, gene expression profiling, and Ig VH-D-JHsequencing, we monitor the initial 10 generations of development of sorted cord blood CD34highLineage−pluripotential progenitors growing in bone marrow S17 stroma cocultures. We show that (i) multipotent progenitors (CD34+CD45RA+CD10−CD19−) directly generate an initial wave of Pax5+TdT−“unilineage” pre/pro-B cells and a later wave of “multilineage” CLP/early-B cells and (ii) the cells generated in these successive stages act as precursors for distinct pro-B cells through two independent layered pathways. Studies by others have tracked the origin of B-lineage leukemias in elderly mice to the mouse B-1a pre/pro-B lineage, which lacks the TdT activity that diversifies the VH-D-JHIg heavy chain joints found in the early-B or B-2 lineage. Here, we show a similar divergence in human B-cell development pathways between the Pax5+TdT−pre/pro-B differentiation pathway that gives rise to infant B-lineage leukemias and the early-B pathway.
Motor output evoked by subsaccadic stimulation of primate frontal eye fields
Authors: Corneil Brian D. , Elsley James K. , Nagy Benjamin , Cushing Sharon L.
Published: March 2010

In addition to its role in shifting the line of sight, the oculomotor system is also involved in the covert orienting of visuospatial attention. Causal evidence supporting this premotor theory of attention, or oculomotor readiness hypothesis, comes from the effect of subsaccadic threshold stimulation of the oculomotor system on behavior and neural activity in the absence of evoked saccades, which parallels the effects of covert attention. Here, by recording neck-muscle activity from monkeys and systematically titrating the level of stimulation current delivered to the frontal eye fields (FEF), we show that such subsaccadic stimulation is not divorced from immediate motor output but instead evokes neck-muscle responses at latencies that approach the minimal conduction time to the motor periphery. On average, neck-muscle thresholds were ∼25% lower than saccade thresholds, and this difference is larger for FEF sites associated with progressively larger saccades. Importantly, we commonly observed lower neck-muscle thresholds even at sites evoking saccades ≤5° in magnitude, although such small saccades are not associated with head motion. Neck-muscle thresholds compare well with the current levels used in previous studies to influence behavior or neural activity through activation of FEF neurons feeding back to extrastriate cortex. Our results complement this previous work by suggesting that the neurobiologic substrate that covertly orients visuospatial attention shares this command with head premotor circuits in the brainstem, culminating with recruitment in the motor periphery.
Role of host protein glutaredoxin 3 in the control of transcription during bacteriophage Φ2954 infection
Authors: Qiao Jian , Qiao Xueying , Sun Yang , Mindich Leonard
Published: March 2010

Bacteriophage Φ2954 contains three dsRNA genomic segments, designated L, M, and S. The RNA is located inside a core particle composed of multiple copies of a major structural protein, an RNA-dependent RNA polymerase, a hexameric NTPase, and an auxiliary protein. The core particle is covered by a shell of protein P8, and this structure is enclosed within a lipid-containing membrane. We have found that normal infection of the host
Pseudomonas syringae
is dependent on the action of a host protein, glutaredoxin 3 (GrxC). GrxC removes the P8 shell from the infecting particle and binds to the inner core. Removal of P8 activates the transcription of segments S and M, whereas binding of GrxC to the core particle activates the transcription of segment L. The differences in transcription behavior are due to the preference of the polymerase for G as the first base of the transcript. Transcripts of segments S and M begin with GCAA, whereas those of segment L begin with ACAA. The binding of GrxC to the particle results in changes in polymerase activity. Mutations resulting in independence of GrxC are found in the gene for protein P1, the major structural protein of the inner core particle.
Diabetes-accelerated memory dysfunction via cerebrovascular inflammation and Aβ deposition in an Alzheimer mouse model with diabetes
Authors: Takeda Shuko , Sato Naoyuki , Uchio-Yamada Kozue , Sawada Kyoko , Kunieda Takanori , Takeuchi Daisuke , Kurinami Hitomi , Shinohara Mitsuru , Rakugi Hiromi , Morishita Ryuichi
Published: March 2010

Recent epidemiological studies suggest that diabetes mellitus is a strong risk factor for Alzheimer disease. However, the underlying mechanisms remain largely unknown. In this study, to investigate the pathophysiological interaction between these diseases, we generated animal models that reflect the pathologic conditions of both diseases. We crossed Alzheimer transgenic mice (APP23) with two types of diabetic mice (
ob
/
ob
and NSY mice), and analyzed their metabolic and brain pathology. The onset of diabetes exacerbated Alzheimer-like cognitive dysfunction without an increase in brain amyloid-β burden in double-mutant (APP
+
-
ob
/
ob
) mice. Notably, APP
+
-
ob
/
ob
mice showed cerebrovascular inflammation and severe amyloid angiopathy. Conversely, the cross-bred mice showed an accelerated diabetic phenotype compared with
ob
/
ob
mice, suggesting that Alzheimer amyloid pathology could aggravate diabetes. Similarly, APP
+
-NSY fusion mice showed more severe glucose intolerance compared with diabetic NSY mice. Furthermore, high-fat diet feeding induced severe memory deficits in APP
+
-NSY mice without an increase in brain amyloid-β load. Here, we created Alzheimer mouse models with early onset of cognitive dysfunction. Cerebrovascular changes and alteration in brain insulin signaling might play a pivotal role in this relationship. These findings could provide insights into this intensely debated association.
Lack of p21 expression links cell cycle control and appendage regeneration in mice
Authors: Bedelbaeva Khamilia , Snyder Andrew , Gourevitch Dmitri , Clark Lise , Zhang Xiang-Ming , Leferovich John , Cheverud James M. , Lieberman Paul , Heber-Katz Ellen
Published: March 2010

Animals capable of regenerating multiple tissue types, organs, and appendages after injury are common yet sporadic and include some sponge, hydra, planarian, and salamander (i.e., newt and axolotl) species, but notably such regenerative capacity is rare in mammals. The adult MRL mouse strain is a rare exception to the rule that mammals do not regenerate appendage tissue. Certain commonalities, such as blastema formation and basement membrane breakdown at the wound site, suggest that MRL mice may share other features with classical regenerators. As reported here, MRL fibroblast-like cells have a distinct cell-cycle (G2/M accumulation) phenotype and a heightened basal and wound site DNA damage/repair response that is also common to classical regenerators and mammalian embryonic stem cells. Additionally, a neutral and alkaline comet assay displayed a persistent level of intrinsic DNA damage in cells derived from the MRL mouse. Similar to mouse ES cells, the p53-target p21 was not expressed in MRL ear fibroblasts. Because the p53/p21 axis plays a central role in the DNA damage response and cell cycle control, we directly tested the hypothesis that p21 down-regulation could functionally induce a regenerative response in an appendage of an otherwise nonregenerating mouse strain. Using the ear hole closure phenotype, a genetically mapped and reliable quantitative indicator of regeneration in the MRL mouse, we show that the unrelated Cdkn1a
tmi/Tyj
/J p21
−/−
mouse (unlike the B6129SF2/J WT control) closes ear holes similar to MRL mice, providing a firm link between cell cycle checkpoint control and tissue regeneration.
Protein-assisted self-assembly of multifunctional nanoparticles
Authors: Nikitin Maxim P. , Zdobnova Tatiana A. , Lukash Sergey V. , Stremovskiy Oleg A. , Deyev Sergey M.
Published: March 2010

A bioengineering method for self-assembly of multifunctional superstructures with in-advance programmable properties has been proposed. The method employs two unique proteins, barnase and barstar, to rapidly join the structural components together directly in water solutions. The properties of the superstructures can be designed on demand by linking different agents of various sizes and chemical nature, designated for specific goals. As a proof of concept, colloidally stable trifunctional structures have been assembled by binding together magnetic particles, quantum dots, and antibodies using barnase and barstar. The assembly has demonstrated that the bonds between these proteins are strong enough to hold macroscopic (5 nm–3 μm) particles together. Specific interaction of such superstructures with cancer cells resulted in fluorescent labeling of the cells and their responsiveness to magnetic field. The method can be used to join inorganic moieties, organic particles, and single biomolecules for synergistic use in different applications such as biosensors, photonics, and nanomedicine.
L-amino acids catalyze the formation of an excess of D-glyceraldehyde, and thus of other D sugars, under credible prebiotic conditions
Authors: Breslow Ronald , Cheng Zhan-Ling
Published: March 2010

Previous work by us, and others, has shown that the formation of amino acids on prebiotic earth with the geometric arrangement called the L configuration can be understood. Some meteorites of the carbonaceous chondritic type deliver unusual amino acids, with alpha-methyl groups, which have an excess of the L isomers. We previously showed that in decarboxylative transamination reactions under credible prebiotic conditions they produce normal amino acids that also have a preference for the L isomer, as is found in our proteins. We, and others, showed that as little as a 1% excess of the L isomers could be amplified up to a 95/5 ratio of L over D on simple evaporation of a solution, so life could start with such a solution in which the dominant L isomers would be selectively chosen. We now find that the geometry of sugars referred to D, as in D-ribose or D-glucose, is not an independent mystery. D-glyceraldehyde, the simplest sugar with a D center, is the basic unit on which other sugars are built. We find that the synthesis of glyceraldehyde by reaction of formaldehyde with glycolaldehyde is catalyzed under prebiotic conditions to D/L ratios greater than 1, to as much as 60/40, by a representative group of L-amino acids (with the exception of L-proline). The D/L glyceraldehyde ratio in water solution is amplified to 92/8 using simple selective solubilities of the D and the DL forms. This D center would then be carried into the prebiotic syntheses of larger sugars.
Dally-like core protein and its mammalian homologues mediate stimulatory and inhibitory effects on Hedgehog signal response
Authors: Williams Elizabeth H. , Pappano William N. , Saunders Adam M. , Kim Min-Sung , Leahy Daniel J. , Beachy Philip A.
Published: March 2010

The distribution and activities of morphogenic signaling proteins such as Hedgehog (Hh) and Wingless (Wg) depend on heparan sulfate proteoglycans (HSPGs). HSPGs consist of a core protein with covalently attached heparan sulfate glycosaminoglycan (GAG) chains. We report that the unmodified core protein of Dally-like (Dlp), an HSPG required for cell-autonomous Hh response in
Drosophila
embryos, alone suffices to rescue embryonic Hh signaling defects. Membrane tethering but not specifically the glycosylphosphatidylinositol linkage characteristic of glypicans is critical for this cell-autonomous activity. Our studies further suggest divergence of the two
Drosophila
and six mammalian glypicans into two functional families, an activating family that rescues cell-autonomous Dlp function in Hh response and a family that inhibits Hh response. Thus, in addition to the previously established requirement for HSPG GAG chains in Hh movement, these findings demonstrate a positive cell-autonomous role for a core protein in morphogen response in vivo and suggest the conservation of a network of antagonistic glypican activities in the regulation of Hh response.
Hypothalamic and pituitary c-Jun N-terminal kinase 1 signaling coordinately regulates glucose metabolism
Authors: Belgardt Bengt F. , Mauer Jan , Wunderlich F. Thomas , Ernst Marianne B. , Pal Martin , Spohn Gabriele , Brönneke Hella S. , Brodesser Susanne , Hampel Brigitte , Schauss Astrid C. , Brüning Jens C.
Published: March 2010

c-Jun N-terminal kinase (JNK) 1-dependent signaling plays a crucial role in the development of obesity-associated insulin resistance. Here we demonstrate that JNK activation not only occurs in peripheral tissues, but also in the hypothalamus and pituitary of obese mice. To resolve the importance of JNK1 signaling in the hypothalamic/pituitary circuitry, we have generated mice with a conditional inactivation of JNK1 in nestin-expressing cells (JNK1
ΔNES
mice). JNK1
ΔNES
mice exhibit improved insulin sensitivity both in the CNS and in peripheral tissues, improved glucose metabolism, as well as protection from hepatic steatosis and adipose tissue dysfunction upon high-fat feeding. Moreover, JNK1
ΔNES
mice also show reduced somatic growth in the presence of reduced circulating growth hormone (GH) and insulin-like growth factor 1 (IGF1) concentrations, as well as increased thyroid axis activity. Collectively, these experiments reveal an unexpected, critical role for hypothalamic/pituitary JNK1 signaling in the coordination of metabolic/endocrine homeostasis.
Ghrelin
O
-acyltransferase (GOAT) is essential for growth hormone-mediated survival of calorie-restricted mice
Authors: Zhao Tong-Jin , Liang Guosheng , Li Robert Lin , Xie Xuefen , Sleeman Mark W. , Murphy Andrew J. , Valenzuela David M. , Yancopoulos George D. , Goldstein Joseph L. , Brown Michael S.
Published: March 2010

Ghrelin
O
-acyltransferase (GOAT) attaches octanoate to proghrelin, which is processed to ghrelin, an octanoylated peptide hormone that stimulates release of growth hormone (GH) from pituitary cells. Elimination of the gene encoding ghrelin or its receptor produces only mild phenotypes in mice. Thus, the essential function of ghrelin is obscure. Here, we eliminate the
Goat
gene in mice, thereby eliminating all octanoylated ghrelin from blood. On normal or high fat diets,

Goat
−/−

mice grew and maintained the same weights as wild-type (WT) littermates. When subjected to 60% calorie restriction, WT and

Goat
−/−

mice both lost 30% of body weight and 75% of body fat within 4 days. In both lines, fasting blood glucose initially declined equally. After 4 days, glucose stabilized in WT mice at 58–76 mg/dL. In

Goat
−/−

mice, glucose continued to decline, reaching 12–36 mg/dL on day 7. At this point, WT mice showed normal physical activity, whereas

Goat
−/−

mice were moribund. GH rose progressively in calorie-restricted WT mice and less in

Goat
−/−

mice. Infusion of either ghrelin or GH normalized blood glucose in

Goat
−/−

mice and prevented death. Thus, an essential function of ghrelin in mice is elevation of GH levels during severe calorie restriction, thereby preserving blood glucose and preventing death.
Religion in the Workplace: Correlates and Consequences of Individual Behavior
Authors: Day Nancy E.
Published: March 2010

Religion is an increasingly important aspect of diversity management. However, while much scholarly work exists regarding spirituality, little addresses relationships between religiosity and individual outcomes that may affect organizational functioning. Reviewing past research from psychology and management literatures, this paper describes correlates of religiosity that may affect individual behavior in the workplace, such as physical and mental health, coping, concern for others, creativity, commitment, ethical behavior, prejudice, intelligence and personality. Recommendations for future research call for theory-based conceptualizations with well-articulated measures conducted in organizational samples.
Virtuous Leadership: A Theoretical Model and Research Agenda
Authors: PEARCE CRAIG L. , WALDMAN DAVID A. , CSIKSZENTMIHALY MIHALY
Published: March 2010

In this manuscript we attempt to shed light on the concept of virtuous leadership. We first attempt to identify the nature of virtuous leadership. Next, we specify two potential antecedents of virtuous vertical leadership. Specifically, we identify the personal characteristic of responsibility disposition as well as environmental cues as potential predictors of subsequent virtuous leadership. Moreover, we articulate how virtuous vertical leadership might result in virtuous shared leadership. We also demonstrate how both vertical and shared virtuous leadership can act as key factors in the creation of organizational learning. Importantly, we specify several important research implications of our theoretical model. Finally, we illustrate several practical considerations when it comes to developing and enhancing virtuous leadership.
Spirituality and Servant Leader Behavior
Authors: BEAZLEY DEBRA , GEMMILL GARY
Published: March 2010

This empirical study was designed to examine the relationship of the personal spirituality beliefs of servant leaders to their actual behavior as servant leaders. For purposes of the study the Spiritual Assessment Scale was used to measure spirituality beliefs while the leadership portion
of the Servant Organizational Leadership Assessment inventory was used to measure servant leadership behavior. The research subjects for the study were 62 managers and 97 subordinates who were employed by TD Industries in Dallas, Texas; an organization that purports to use servant leadership
philosophy. The research results revealed that the more managers were perceived as servant leaders the more likely they were to have both stronger spirituality beliefs particularly in those related to moral philosophies that emphasize the virtues of honesty, humility, and service to others.
Additionally, an ANOVA and post hoc pairwise multiple comparison indicated a difference in perception of servant leadership behavior due to years spent studying servant leadership principles and years employed at TD Industries.