bluuebunny/crossref_metadata_2025 huggingface dataset:
Parity induces differentiation and reduces Wnt/Notch signaling ratio and proliferation potential of basal stem/progenitor cells isolated from mouse mammary epithelium
Authors: Meier-Abt Fabienne , Milani Emanuela , Roloff Tim , Brinkhaus Heike , Duss Stephan , Meyer Dominique S , Klebba Ina , Balwierz Piotr J , van Nimwegen Erik , Bentires-Alj Mohamed
Published: April 2013

Introduction

Early pregnancy has a strong protective effect against breast cancer in humans and rodents, but the underlying mechanism is unknown. Because breast cancers are thought to arise from specific cell subpopulations of mammary epithelia, we studied the effect of parity on the transcriptome and the differentiation/proliferation potential of specific luminal and basal mammary cells in mice.

Methods

Mammary epithelial cell subpopulations (luminal Sca1-, luminal Sca1+, basal stem/progenitor, and basal myoepithelial cells) were isolated by flow cytometry from parous and age-matched virgin mice and examined by using a combination of unbiased genomics, bioinformatics, in vitro colony formation, and in vivo limiting dilution transplantation assays. Specific findings were further investigated with immunohistochemistry in entire glands of parous and age-matched virgin mice.

Results

Transcriptome analysis revealed an upregulation of differentiation genes and a marked decrease in the Wnt/Notch signaling ratio in basal stem/progenitor cells of parous mice. Separate bioinformatics analyses showed reduced activity for the canonical Wnt transcription factor LEF1/TCF7 and increased activity for the Wnt repressor TCF3. This finding was specific for basal stem/progenitor cells and was associated with downregulation of potentially carcinogenic pathways and a reduction in the proliferation potential of this cell subpopulation in vitro and in vivo. As a possible mechanism for decreased Wnt signaling in basal stem/progenitor cells, we found a more than threefold reduction in the expression of the secreted Wnt ligand Wnt4 in total mammary cells from parous mice, which corresponded to a similar decrease in the proportion of Wnt4-secreting and estrogen/progesterone receptor-positive cells. Because recombinant Wnt4 rescued the proliferation defect of basal stem/progenitor cells in vitro, reduced Wnt4 secretion appears to be causally related to parity-induced alterations of basal stem/progenitor cell properties in mice.

Conclusions

By revealing that parity induces differentiation and downregulates the Wnt/Notch signaling ratio and the in vitro and in vivo proliferation potential of basal stem/progenitor cells in mice, our study sheds light on the long-term consequences of an early pregnancy. Furthermore, it opens the door to future studies assessing whether inhibitors of the Wnt pathway may be used to mimic the parity-induced protective effect against breast cancer.
EMu: probabilistic inference of mutational processes and their localization in the cancer genome
Authors: Fischer Andrej , Illingworth Christopher JR , Campbell Peter J , Mustonen Ville
Published: April 2013

The spectrum of mutations discovered in cancer genomes can be explained by the activity of a few elementary mutational processes. We present a novel probabilistic method, EMu, to infer the mutational signatures of these processes from a collection of sequenced tumors. EMu naturally incorporates the tumor-specific opportunity for different mutation types according to sequence composition. Applying EMu to breast cancer data, we derive detailed maps of the activity of each process, both genome-wide and within specific local regions of the genome. Our work provides new opportunities to study the mutational processes underlying cancer development. EMu is available at http://www.sanger.ac.uk/resources/software/emu/.
The dual effect of mesenchymal stem cells on tumour growth and tumour angiogenesis
Authors: Kéramidas Michelle , de Fraipont Florence , Karageorgis Anastassia , Moisan Anaïck , Persoons Virginie , Richard Marie-Jeanne , Coll Jean-Luc , Rome Claire
Published: April 2013

Introduction

Understanding the multiple biological functions played by human mesenchymal stem cells (hMSCs) as well as their development as therapeutics in regenerative medicine or in cancer treatment are major fields of research. Indeed, it has been established that hMSCs play a central role in the pathogenesis and progression of tumours, but their impact on tumour growth remains controversial.

Methods

In this study, we investigated the influence of hMSCs on the growth of pre-established tumours. We engrafted nude mice with luciferase-positive mouse adenocarcinoma cells (TSA-Luc+) to obtain subcutaneous or lung tumours. When tumour presence was confirmed by non-invasive bioluminescence imaging, hMSCs were injected into the periphery of the SC tumours or delivered by systemic intravenous injection in mice bearing either SC tumours or lung metastasis.

Results

Regardless of the tumour model and mode of hMSC injection, hMSC administration was always associated with decreased tumour growth due to an inhibition of tumour cell proliferation, likely resulting from deep modifications of the tumour angiogenesis. Indeed, we established that although hMSCs can induce the formation of new blood vessels in a non-tumoural cellulose sponge model in mice, they do not modify the overall amount of haemoglobin delivered into the SC tumours or lung metastasis. We observed that these tumour vessels were reduced in number but were longer.

Conclusions

Our results suggest that hMSCs injection decreased solid tumour growth in mice and modified tumour vasculature, which confirms hMSCs could be interesting to use for the treatment of pre-established tumours.
Nonlinear scattering based imaging in elastic media: Theory, theorems, and imaging conditions
Authors: Ravasi Matteo , Curtis Andrew
Published: April 2013

With the more widespread introduction of multicomponent recording devices in land and marine ocean-bottom seismic acquisition, elastic imaging may become mainstream in coming years. We have derived new, nonlinear, elastic imaging conditions. A correlation-type representation theorem for perturbed elastic media, commonly used in seismic interferometry to explain how a scattered wave response between two receivers/sources may be predicted given a boundary of sources/receivers, can be considered as a starting point for the derivation. Here, we use this theorem to derive and interpret imaging conditions for elastic migration by wavefield extrapolation (e.g., elastic reverse-time migration). Some approximations lead to a known, heuristically derived imaging condition that crosscorrelates P- and S-wave potentials that are separated in the subsurface after full-wavefield extrapolation. This formal connection reveals that the nonapproximated correlation-type representation theorem can be interpreted as a nonlinear imaging condition, that accounts also for multiply scattered and multiply converted waves, properly focusing such energy at each image point. We present a synthetic data example using either an ideal (acquisition on a full, closed boundary) or a real (partial boundary) seismic exploration survey, and we demonstrate the importance of nonlinearities in pure- and converted-mode imaging. In PP imaging, they result in better illumination and artifact reduction, whereas in PS imaging they show how zero time-lag and zero space-lag crosscorrelation imaging conditions are not ideal for imaging of converted-mode waves because no conversion arises from zero-offset experiments.
Noncontacting benchtop measurements of the elastic properties of shales
Authors: Blum Thomas E. , Adam Ludmila , van Wijk Kasper
Published: April 2013

We evaluated a laser-based noncontacting method to measure the elastic anisotropy of horizontal shale cores. Whereas conventional transducer data contained an ambiguity between phase and group velocity measurements, small laser source and receiver footprints on typical core samples ensured group velocity information in our laboratory measurements. With a single dense acquisition of group velocity versus group angle on a horizontal core, we estimated the elastic constants [Formula: see text], [Formula: see text], and [Formula: see text] directly from ultrasonic waveforms, and [Formula: see text] from a least-squares fit of modeled to measured group velocities. The observed significant P-wave velocity and attenuation anisotropy in these dry shales were almost surely exaggerated by delamination of clay platelets and microfracturing, but provided an illustration of the new laboratory measurement technique. Although challenges lay ahead to measure preserved shales at in situ conditions in the lab, we evaluated the fundamental advantages of the proposed method over conventional transducer measurements.
Sensitivity analysis from single-well ERT simulations to image CO2 migrations along wellbores
Authors: Picotti Stefano , Gei Davide , Carcione José M. , Grünhut Vivian , Osella Ana
Published: April 2013

CO2 plume imaging is a required step in CO2 geological storage for both performance assessment and risk management purposes. This work has been performed in the frame of the CO2CARE project, and its aim is to develop tools and methodologies to monitor CO2 migration and verify the long-term well integrity after site abandonment. The timely detection of an anomaly is essential to perform a suitable remediation. For this purpose, downhole tools are permanently installed, but it is important to check the resolution and efficiency of the adopted techniques. In particular, this study investigates the possibility of using electrical resistivity tomography (ERT) to image CO2 migrations around observation boreholes through a sensitivity study.
Going nodal—Regional 3D seismic acquisition in Cook Inlet, Alaska
Authors: Yates Mike , Adiletta Steve
Published: April 2013

Apache Corporation began work exploring for hydrocarbons in Alaska's Cook Inlet in 2010 with Apache's first acquisition of exploration leases in this known petroleum province. In early 2011, an extensive 2D seismic acquisition test program was acquired and analyzed to evaluate the effectiveness of a nodal seismic recording system for a multiyear all-season regional 3D seismic acquisition program in this region, often considered one of the toughest places on Earth to record seismic data.
Generic formal fibers and analytically ramified stable rings
Authors: Olberding Bruce
Published: April 2013

LetAbe a local Noetherian domain of Krull dimensiond. Heinzer, Rotthaus, and Sally have shown that if the generic formal fiber ofAhas dimensiond– 1, thenAis birationally dominated by a 1-dimensional analytically ramified local Noetherian ring having residue field finite over the residue field ofA. We explore further this correspondence between prime ideals in the generic formal fiber and 1-dimensional analytically ramified local rings. Our main focus is on the case where the analytically ramified local rings are stable, and we show that in this case the embedding dimension of the stable ring reflects the embedding dimension of a prime ideal maximal in the generic formal fiber, thus providing a measure of how far the generic formal fiber deviates from regularity. A number of characterizations of analytically ramified local stable domains are also given.
New ligand platforms featuring boron-rich clusters as organomimetic substituents
Authors: Spokoyny Alexander M.
Published: April 2013

200 years of research with carbon-rich molecules have shaped the development of modern chemistry. Research pertaining to the chemistry of boron-rich species has historically trailed behind its more distinguished neighbor (carbon) in the periodic table. Notably, a potentially rich and, in many cases, unmatched field of coordination chemistry using boron-rich clusters remains fundamentally underdeveloped. Our work has been devoted to examining several basic concepts related to the functionalization of icosahedral boron-rich clusters and their use as ligands, aimed at designing fundamentally new hybrid molecular motifs and materials. Particularly interesting are icosahedral carboranes, which can be regarded as 3D analogs of benzene. These species comprise a class of boron-rich clusters that were discovered in the 1950s during the “space race” while researchers were developing energetic materials for rocket fuels. Ultimately, the unique chemical and physical properties of carborane species, such as rigidity, indefinite stability to air and moisture, and 3D aromaticity, may allow one to access a set of properties not normally available in carbon-based chemistry. While technically these species are considered as inorganic clusters, the chemical properties they possess make these boron-rich species suitable for replacing and/or altering structural and functional features of the organic and organometallic molecules—a phenomenon best described as “organomimetic”. Aside from purely fundamental features associated with the organomimetic chemistry of icosahedral carboranes, their use can also provide new avenues in the development of systems relevant to solving current problems associated with energy production, storage, and conversion.
Predicting and Managing Consumers' Package Size Impressions
Authors: Ordabayeva Nailya , Chandon Pierre
Published: April 2013

With rising public concerns about waste and overconsumption, predicting and effectively managing consumers' package size impressions have become critical for both marketers and public health advocates. The AddChange heuristic model of size impression assumes that people add (rather than multiply) the percentage changes in the height, width, and length of objects to compute their volume. This simple deterministic model does not require any data to accurately predict consumers' perceptions of product downsizing and supersizing when one, two, or all three dimensions change proportionately. It also explains why consumers perceive size reductions accurately when only one dimension of the package is reduced but completely fail to notice up to a 24% downsizing when the product is elongated in the manner specified by the model, even when they pay close attention or weigh the product by hand. The model can be used to determine the dimensions of packages that create accurate size perceptions or that increase consumers' acceptance of downsizing.
Can Land Reform Avoid a Left Turn? Evidence from Chile after the Cuban Revolution
Authors: González Felipe
Published: April 2013

Following the creation of the Alliance for Progress in 1961, several structural reforms were implemented in Latin America in response to the political effects of the Cuban Revolution. Among these, land reform was arguably the most important policy. Using a unique dataset of land expropriations, and a plausible exogenous variation in land concentration, this paper studies the causal effects this policy had on political support for the incumbent party in the central government. In a context where the incumbent was losing political support (and the power of the left wing was rising), municipalities affected by land reform voted by 3–5 percentage points higher for the incumbent than municipalities not affected by this process. Although it did not prevent the first democratically elected Marxist government, land reform decreased the political support for the left wing party. I discuss several theoretical mechanisms that can explain this empirical result.
Multi-task Research and Research Joint Ventures
Authors: La Manna Manfredi M.
Published: April 2013

The paper shows that, whenever the completion of a research project requires the overcoming ofmore than oneresearch obstacle, then Research Joint Ventures enjoy an intrinsic advantage relative to independent firms. This advantage, which has hitherto escaped attention in the RJV literature, relates to the RJV’s ability toorganizeresearch more efficiently than independent firms. The fact that RJVs can be both more profitable and yield higher expected net welfare than independent firms is surprising because it is derived from a model in which RJVs donotoptimize over R&D investment. The paper exploits a basic result in systems reliability theory to establish the organizational superiority of RJVs.
Action-induced nested classes of groups and jump (co)homology
Authors: Petrosyan Nansen
Published: April 2013

Using fixed-point-free group actions, we set up a scheme to define nested classes of groups indexed over ordinals. Restricting to cellular actions on CW-complexes, we find new classes of groups as well as new characterizations for some well-known classes. We extend some of the properties of the cohomological dimension of a group to groups with jump (co)homology and study their implications to cellular actions on finite dimensional CW-complexes that satisfy a quite general homological condition.
Effectiveness of a participative community singing program to improve health behaviors and increase physical activity in Australian Aboriginal and Torres Strait Islander people
Authors: Sun Jing , Buys Nicholas
Published: April 2013

Aboriginal and Torres Strait Islander individuals continue to experience greater levels of chronic disease than the general Australian population. Evidence suggests that increased sedentary behaviors compared with the traditional healthy and active lifestyles of this population have contributed to this situation. This investigation aimed to examine the health benefits of a community-based singing activity intervention on chronic disease among Aboriginal and Torres Strait Islander Australians.

From 2010 to 2011, 291 Aboriginal and Torres Strait Islander people, from Queensland, Australia, were recruited through five communities to participate in a 1-year community singing program. Participants completed a survey, in the pre- and post-intervention phases of the study, that measured social connectedness, health behavior (e.g., smoking, alcohol consumption), frequency of exercise and art activities, and medication use.

Improvements in health behavior were observed for both male and female participants with chronic disease of all age groups in the community singing program. Improvements in the male and female participants included decreased social loneliness and reduced smoking behavior, increased social support, and increased participation in exercise and art activities.

The participative community singing program was successful in improving the health status and increasing physical activity among Aboriginal and Torres Strait Islander adults.
Spatial Characterization of the Dynamic Response of Frequencies Utilizing Structural Partition Procedure for Large-Scale Power System
Authors: Yang Deyou
Published: April 2013

The aim of this paper is to present an algorithm for analysing the actual spatial characterization of the dynamic responses of frequencies for large-scale power system. Based on the distribution feature of disturbance power, the measure of interaction (MI) is employed to analyse and quantify the strength of connection among the busses and generation units. The MI takes into account the interconnection constraints among network structure and parameters. In particular, only the network parameters are used in the proposed structural partition procedure. Case Studies carried out on the IEEE 68-bus system are presented to demonstrate the application and effectiveness of the technique developed. Investigations show that the spatial characterization of the dynamic responses of frequencies can be accurately obtained with the procedure, independent of fault location and the size of disturbance, since the proposed technique is based on the structural feature of the system.
Online Assessment of Voltage Stability in Power Systems with PMUs
Authors: Chitare Prasad Bhagwat , Murthy Balijepalli V.S.K. , Khaparde S.A.
Published: April 2013

Abstract: For the assessment of voltage instability which comprises the detection of voltage instability and identification of critical buses, two indices namely, system wide Qtax, and bus-specific qtax, are proposed. The Qtax, based on the sensitivity of the reactive power injections to the loading in the system provides early detection of impending voltage instability. The computed qtax indices identify the critcal buses among the load buses in the system. The identified critical buses provided optimal lacations for the corrective control actions for averting voltage instability. Additionally, for voltage stability monitoring, determining the poing of exhaustion of the reactive reserves in system is also crucial. This is addressed by proposed Q-Monitoring Index (QMI), which is the ratio of the reactive component of the source current to the sink current that flows through the adjacent transmission line. These proposed indices together can provide early indication to impending voltage instability. This has been illustrated on IEEE-39 bus system. The reactive support on identified critical buses results in maximum increase in the loadability of the system.
A cost-benefit analysis: implementing temporary disability insurance in Washington State
Authors: Jacoby Dan F.
Published: April 2013

Five states and Puerto Rico currently provide disability insurance to persons unable to work due to temporary disability. No states have adopted such policies since 1969. Labor unions and other advocacy groups have advanced bills in Washington and Oregon that would establish a public disability insurance plan to provide partial wage replacement for serious illness, accident and pregnancy. This paper estimates annual costs and benefits for a temporary disability insurance program in Washington State under the assumption that it would mirror the disability provisions in California without paid family leave.
Immune activation and inflammation increase the plasma phenylalanine-to-tyrosine ratio
Authors: Geisler Simon , Gostner Johanna M. , Becker Kathrin , Ueberall Florian , Fuchs Dietmar
Published: April 2013

The proinflammatory cytokine interferon (IFN) γ activates GTP-cyclohydrolase I. In turn, the production of neopterin in human monocytic cells and of 5,6,7,8-tetrahydrobiopterin (BH4) in other human cells and cells of other species is markedly upregulated. BH4 is cofactor for the biosynthesis of the neurotransmitters 5-hydroxytryptamine (serotonin) and the catecholamines dopamine, epinephrine (adrenaline), and norepinephrine (noradrenaline). The finding of increased neopterin concentrations in patients with viral infections, autoimmune syndromes, malignant tumors, and during treatment with specific cytokines corresponds well with its immunobiological background. However, there is no clear information about BH4 concentrations in these patients. Furthermore, higher blood phenylalanine (Phe)-to-tyrosine (Tyr) ratios have been described in patients with ovarian cancer, after multiple trauma and with sepsis, in patients with HIV-1 infection, in elderly individuals, and in patients with HCV infection under IFN-α therapy. Recent studies already showed that the alterations of Phe metabolism are associated with mood changes and depression. Results point to an impaired hydroxylation of Phe when the enzyme phenylalanine 4-hydroxylase (PAH) is less efficient. As the decrease of PAH activity might result from a diminished availability of BH4, the determination of the Phe/Tyr ratio may serve as an indirect measure of BH4 availability.
Immune activation and inflammation in patients with cardiovascular disease are associated with elevated phenylalanine-to-tyrosine ratios
Authors: Mangge Harald , Schnedl Wolfgang J. , Schröcksnadel Sebastian , Geisler Simon , Murr Christian , Fuchs Dietmar
Published: April 2013

Higher serum neopterin concentrations and kynurenine-to-tryptophan (Kyn/Trp) ratios are associated with increased mortality in patients with coronary artery disease (CAD). Preferentially, Th1-type cytokine interferon-γ stimulates tryptophan breakdown and neopterin production by GTP cyclohydrolase I (GCH-I) in parallel in monocyte-derived macrophages and dendritic cells. In other cells, activation of GCH-I leads to the formation of 5,6,7,8-tetrahydrobiopterin (BH4), the necessary cofactor of amino acid hydroxylases such as phenylalanine 4-hydroxylase (PAH) and nitric oxide synthases. In 31 CAD patients (70.3±9.9 years; 21 males, 10 females), we determined serum concentrations of phenylalanine, tyrosine, and Kyn/Trp by HPLC, neopterin by ELISA, and nitrite by the colorimetric Griess assay. The phenylalanine-to-tyrosine ratio (Phe/Tyr) served as an estimate of PAH enzyme activity. Elevated Phe/Tyr concentrations were detected in a subgroup of CAD patients and correlated with Kyn/Trp (r=0.396, p<0.05) and neopterin (r=0.354, p<0.05) and inversely with nitrite (r=–0.371, p<0.05) concentrations. Higher Phe/Tyr in patients is associated with immune activation and indicates subnormal PAH activity that might be involved in the precipitation of neuropsychiatric symptoms in CAD patients.
Amino acid hexafluorosilicates – an overview
Authors: Fleck Michel , Ghazaryan Vahram V. , Petrosyan Aram M.
Published: April 2013

Single crystal data on eight new hexafluorosilicate salts of amino acids are presented in this work. This includes crystal and molecular structures of the following salts: 2 β-Ala · H2SiF6 (I), 2 Bet · H2SiF6 (II), 2L-Orn · H2SiF6 (III), 2L-Ser · H2SiF6 (IV), 2L-Leu · H2SiF6 · 2 H2O (V), 2L-Ile · H2SiF6 · 2 H2O (VI), 2L-Met · H2SiF6 · H2O (VII), and 2L-Asp · H2SiF6 · 2 H2O (VIII). In all these crystals, the SiF6-anion is ordered, except for (III), where disorder of the fluorine atoms occurs. An analysis of previously published data on amino acid hexafluorosilicates showed that the amount of hydrogen bonding towards the SiF6-anion is an indication of disorder – we found that all structures with 0.6 or less hydrogen bonds per fluorine atom have disorder.
Investigation of Specimen- and Grain-Size Dependence of Yield Stress in Electrodeposited Nanocrystalline Copper through Micropillar Compression
Authors: Okamoto Norihiko L. , Kashioka Daisuke , Inui Haruyuki
Published: April 2013

The specimen-size dependence of yield stress of nanocrystalline copper with average grain size (d) of 360 nm has been investigated through uniaxial compression tests of micrometer-size pillars fabricated via the focused ion beam method. The yield stress decreases with the decrease in the micropillar size while the yield stress is almost constant for larger micropillars. The critical specimen size (t) is approximately 12.5 μm, correspoinding to the critical (t/d) value, (t/d)*, of 35, which is much larger than that for coarse-grained copper polycrystals.
Radiation resistance of nano-structured tungsten-rhenium sheet
Authors: Armstrong David E.J. , Roberts Steve G.
Published: April 2013

Tungsten is one the most important material for both plasma facing and structural applications in current designs for advanced divertors. Recent work has shown that composites can be manufactured from nanostructured tungsten foils which show significantly higher toughness than monolithic tungsten, but there is no data on the radiation resistance of such materials. In this study W-5 wt% Re foil in both an as rolled and annealed condition was implanted with 2MeV W+ ions to two damage levels, 0.07 and 0.4 dpa. The change in hardness was measured using nanoindentation. An increase in hardness was seen in both materials at both damage levels, with more hardening seen for the 0.4 dpa implanted samples. However the increase in hardness due to ion implantation was 2.6 times higher in the annealed material as compared to the as rolled material. This is due to the smaller grain size and higher dislocation density providing more sinks for the irradiation produced defects in the as rolled material as compared to the annealed material. Thus showing that unannealed tungsten foils are superior for use in applications in which they will see significant levels of radiation damage.
Development of Low-Temperature Sintering Cu Nanoparticles
Authors: Ishizaki Toshitaka , Watanabe Ryota , Akedo Kunio , Satoh Toshikazu
Published: April 2013

Cu nanoparticles capped with fatty acids and amines were developed as low-temperature sintering materials. The fatty acids and amines used were decanoic acid + decyl amine (C10) and oleic acid + oleyl amine (C18), respectively. The synthesized Cu nanoparticles were analyzed using X-ray diffraction, transmission electron microscopy, and thermogravimetric and differential thermal analysis. Because both of the capping layers could be decomposed at temperatures lower than 300°C even under an inert atmosphere, bonding and sintering experiments could be carried out in the absence of oxygen to prevent the oxidation of the Cu nanoparticles. The sintered structures were observed using scanning electron microscopy. The shear strengths of Cu plates bonded using the C18 Cu nanoparticles were larger than those of plates bonded using the C10 Cu nanoparticles. At 300°C, the strength was higher than 30 MPa, and of the same order as ordinary high-temperature solders, even though the processing temperature was low. The resistivity of a film sintered using the C18 Cu nanoparticles was 12 μΩcm at 300°C, which was lower than the values reported in previous studies.
Study on the Production of Silver/Modified Clay Nanocomposites
Authors: Pessanha Natália F. N. , Coelho Gerson L. V.
Published: April 2013

The aim of this study was to investigate the application of modified clay as a support in the synthesis of silver nanoparticles. Silver nitrate (AgNO3) was used as the silver precursor in several concentrations (0.005 M, 0.01 M, 0.02 M, 0.05 M, and 0.1 M) to obtain Ag-MMT purified and modified clay nanocomposites. The properties of nanocomposites were also studied as a function of the concentration of the reducing agent, sodium borohydride (NaBH4). It was observed through X-ray Diffraction that the MMT purified structure was gradually exfoliated with increased concentrations of AgNO3, while the modified clay structure remained intact. As observed through UV-vis spectra, samples of Ag+-MMT were reduced with NaBH4 to produce Ago and its particle diameter is dependent on the concentration of NaBH4.
Multifunctional silicone nanocomposites for advanced LED encapsulation
Authors: Li Ying , Tao Peng , Siegel Richard W. , Schadler Linda S.
Published: April 2013

The addition of high refractive index (RI) inorganic nanoparticles (NPs) to LED encapsulation materials can lead to higher light extraction efficiency. In addition, the NPs can be carriers for additional functionality such as color conversion. Using a simple “grafting-to” approach, bimodal polydimethylsiloxane (PDMS) brushes were grafted onto high-RI ZrO2 NPs. Subsequently, an organic phosphor, 6-[fluorescein-5(6)-carboxamido]hexanoic acid (FCHA), was attached onto the PDMS-grafted ZrO2 NPs via a facile ligand exchange process. The bimodal polymer brush design enables homogenous dispersion of the surface functionalized NPs within the silicone matrix. The functionalized NPs with ∼53 wt% ZrO2 core have a ∼0.08 higher RI than neat silicone, and the NP-filled silicone nanocomposites exhibit a transparency of ∼ 90% in the 550-800 nm wavelength range. In addition, the nanocomposites could be excited at a wavelength around 455 nm by a blue LED and undergo secondary yellow emission at around 571 nm. It is expected that the prepared nanocomposites can be used as high-efficiency, non-scattering, color-tuned materials for advanced LED encapsulation.
Insights and issues with simulating terrestrial DOC loading of Arctic river networks
Authors: Kicklighter David W. , Hayes Daniel J. , McClelland James W. , Peterson Bruce J. , McGuire A. David , Melillo Jerry M.
Published: April 2013

Terrestrial carbon dynamics influence the contribution of dissolved organic carbon (DOC) to river networks in addition to hydrology. In this study, we use a biogeochemical process model to simulate the lateral transfer of DOC from land to the Arctic Ocean via riverine transport. We estimate that, over the 20th century, the pan‐Arctic watershed has contributed, on average, 32 Tg C/yr of DOC to river networks emptying into the Arctic Ocean with most of the DOC coming from the extensive area of boreal deciduous needle‐leaved forests and forested wetlands in Eurasian watersheds. We also estimate that the rate of terrestrial DOC loading has been increasing by 0.037 Tg C/yr2 over the 20th century primarily as a result of climate‐induced increases in water yield. These increases have been offset by decreases in terrestrial DOC loading caused by wildfires. Other environmental factors (CO2 fertilization, ozone pollution, atmospheric nitrogen deposition, timber harvest, agriculture) are estimated to have relatively small effects on terrestrial DOC loading to Arctic rivers. The effects of the various environmental factors on terrestrial carbon dynamics have both offset and enhanced concurrent effects on hydrology to influence terrestrial DOC loading and may be changing the relative importance of terrestrial carbon dynamics on this carbon flux. Improvements in simulating terrestrial DOC loading to pan‐Arctic rivers in the future will require better information on the production and consumption of DOC within the soil profile, the transfer of DOC from land to headwater streams, the spatial distribution of precipitation and its temporal trends, carbon dynamics of larch‐dominated ecosystems in eastern Siberia, and the role of industrial organic effluents on carbon budgets of rivers in western Russia.
An Inventory of Crop Wild Relatives of the United States
Authors: Khoury Colin K. , Greene Stephanie , Wiersema John , Maxted Nigel , Jarvis Andy , Struik Paul C.
Published: April 2013

The use of crop wild relatives (CWRs) in breeding is likely to continue to intensify as utilization techniques improve and crop adaptation to climate change becomes more pressing. Significant gaps remain in the conservation of these genetic resources. As a first step toward a national strategy for the conservation of CWRs, we present an inventory of taxa occurring in the United States, with suggested prioritization of species based on potential value in crop improvement. We listed 4600 taxa from 985 genera and 194 plant families, including CWRs of potential value via breeding as well as wild species of direct use for food, forage, medicine, herb, ornamental, and/or environmental restoration purposes. United States CWRs are related to a broad range of important food, forage and feed, medicinal, ornamental, and industrial crops. Some potentially valuable species are threatened in the wild, including relatives of sunflower (Helianthus annuus L.), walnut (Juglans regia L.), pepo squash (Cucurbita pepo L.), wild rice (Zizania L.), raspberry (Rubus idaeus L.), and plum (Prunus salicina Lindl.), and few accessions of such taxa are currently conserved ex situ. We prioritize 821 taxa from 69 genera primarily related to major food crops, particularly the approximately 285 native taxa from 30 genera that are most closely related to such crops. Both the urgent collection for ex situ conservation and the management of such taxa in protected areas are warranted, necessitating partnerships between concerned organizations, aligned with regional and global initiatives to conserve and provide access to CWR diversity.
Adaptive management and governance of Delaware River water resources
Authors: Mandarano Lynn A. , Mason Robert J.
Published: April 2013

This paper articulates the complexities of adaptively managing Delaware River water resources to meet shifting priorities of drinking water supply, drought mitigation and flood mitigation, as well as conflicting stakeholder interests. In particular, the paper examines the short-term and long-term programs that comprise the Delaware River Basin Commission's (DRBC) and the 1954 US Supreme Court Decree parties' successful adaptive management approach that seeks to balance the growing list of demands for water resources management, including drinking water supply, drought management, flood control and cold water fisheries protection. Review of the DRBC's adaptive governance approach reveals the critical complexities of designing experimental, yet science-driven management approaches and effectively engaging various sets of stakeholders in the associated decision-making processes.
Analysis of water pricing in Ireland and recommendations towards a more efficient water sector
Authors: Brady J. , Gray N. F.
Published: April 2013

Within Ireland, both the public water supply and group water scheme (GWS) sectors are crucial entities in the provision of water supply to individuals. In this study, variances in water charges and operation are assessed via an in-depth survey of 104 GWSs in order to establish the range in both domestic and commercial charges, and also to establish the factors influencing these charges within the rural water sector. Results are compared with the commercial water charges of the 34 local authorities involved in the provision of public water and wastewater services. Devoid of regulation, tariff setting is highly decentralised with substantial variations in connection, fixed and volumetric charges across both sectors. Greater transparency is essential to establish the full cost of supply to domestic and non-domestic consumers. Findings reveal average GWS volumetric charges to be 35% lower than public supplies, resulting in communities wishing to retain ownership of their schemes as there is much greater control over water pricing. Historic underinvestment has led to an infrastructure deficit and deficiencies within the public supply sector are discussed, such as inadequate revenue collection and high unaccounted-for water. Furthermore, recommendations are made towards effective operation and pricing in light of proposed government plans to establish a national water authority.
Tapped out: how can cities secure their water future?
Authors: Richter Brian D. , Abell David , Bacha Emily , Brauman Kate , Calos Stavros , Cohn Alex , Disla Carlos , O'Brien Sarah Friedlander , Hodges David , Kaiser Scott , Loughran Maria , Mestre Cristina , Reardon Melissa , Siegfried Emma
Published: April 2013

Cities around the world are struggling to access additional water supplies to support their continued growth because their freshwater sources are becoming exhausted. Half of all cities with populations greater than 100,000 are located in water-scarce basins, and in these basins agricultural water consumption accounts for more than 90% of all freshwater depletions. In this paper we review the water development histories of four major cities: Adelaide, Phoenix, San Antonio and San Diego. We identify a similar pattern of water development in these cities, which begins with the exhaustion of local surface and groundwater supplies, continues with importation of water from other basins, and then turns to recycling of wastewater or stormwater, or desalination of either seawater or brackish groundwater. Demand management through water conservation has mitigated, to varying degrees, the timing of water-system expansions and the extent to which cities rely on new sources of supply. This typical water development pattern in cities is undesirable from a sustainability perspective, as it is usually associated with serious ecological and social impacts as well as sub-optimal cost effectiveness. We highlight case examples and opportunities to invest in water conservation measures, particularly through urban–rural partnerships under which cities work with farmers to implement irrigation conservation measures, thereby freeing up water for ecological restoration and use by cities.
Quadratic level quasigroup equations with four variables II: The Lattice of varieties
Authors: Krapez Aleksandar
Published: April 2013

We consider a class of quasigroup identities (with one operation symbol) of
the form x1x2?x3x4=x5x6?x7x8 and with xi?{x, y, u, v} (1? i ? 8)
with each of x, y, u, v occurring exactly twice in the identity. There are
105 such identities. They generate 26 quasigroup varieties. The lattice of
these varieties is given.
Total reduction of linear systems of operator equations with the system matrix in the companion form
Authors: Jovovic Ivana
Published: April 2013

We consider a total reduction of a nonhomogeneous linear system of operator
equations with the system matrix in the companion form. Totally reduced
system obtained in this manner is completely decoupled, i.e., it is a system
with separated variables. We introduce a method for the total reduction, not
by a change of basis, but by finding the adjugate matrix of the
characteristic matrix of the system matrix. We also indicate how this
technique may be used to connect differential transcendence of the solution
with the coefficients of the system.
Spaces with σ-locally finite Lindelöf sn-networks
Authors: Tuyen Luong
Published: April 2013

We prove that a space X has a ?-locally finite Lindel?f sn-network if and
only if X is a compact-covering compact and mssc-image of a locally separable
metric space, if and only if X is a sequentially-quotient ? and mssc-image of
a locally separable metric space, where ?compact-covering? (or
?sequentially-quotient?) can not be replaced by ?sequence-covering?. As an
application, we give a new characterization of spaces with locally countable
weak bases.
An implementation of infrared thermography in maintenance plans within a world class manufacturing strategy
Authors: Todorovic Petar , Gordic Dusan , Babic Milun , Jeremic Branislav , Demichela Micaela , Macuzic Ivan
Published: April 2013

The objective of the paper is to show the implementation of infrared
thermography within World Class Manufacturing (WCM) maintenance strategy. The
results from infrared thermography inspections in a food processing and
packaging solutions company were presented. Applicability of the infrared
thermography, during a two-year period, caused a substantial reduction the
potential breakdown in the pilot area. Upon feasibility confirmation, the
proposed method was spread to other production equipment of the company.
Effects of an adiabatic fin on the mixed convection heat transfer in a square cavity with two ventilation ports
Authors: Selimefendigil Fatih , Öztop Hakan
Published: April 2013

In this study, a square cavity with two ventilation ports in the presence of
an adi-abatic fin of different lengths placed on the walls of the cavity is
numerically analyzed for the mixed convection case for a range of
Richardson numbers (Ri=0.1,1, 10, 100) and at Reynolds number of 300. The
effect of the fin height, placement of the fin on each of the four walls of the
cavity and Richardson number on the heat transfer and fluid flow characteristics
is numerically analyzed. The results are presented in terms of streamlines,
isotherm plots and averaged Nusselt number plots. It is observed that for
the convection dominated case, fin length and its position on the one of the
four walls of the cavity do not alter the thermal performance whereas when
the buoyancy effects become important thermal performance increases for high
fin length.
The Effect of National Culture, Acculturation, and Education on Accounting Judgments: A Comparative Study of Australian and Chinese Culture
Authors: Hu Ceelsan , Chand Parmod , Evans Elaine
Published: April 2013

We examine the influence of national culture on the judgments of Australian and Chinese tertiary accounting students when they are interpreting selected International Financial Reporting Standards (IFRSs) that contain uncertainty expressions. To extend prior cross-cultural research, we also examine whether cultural values of individuals can change because of acculturation and accounting education, and measure their potential impact on accounting judgment. The results provide strong support for the notion that Chinese accounting students are more conservative than Australian accounting students in assigning probabilities to in-context uncertainty expressions contained in IFRSs. A unique finding of this study is that the cultural values of individuals can change because of acculturation and accounting education, and this could potentially improve the comparability of financial reports by moderating differences in the interpretation of accounting standards caused by cultural differences between accountants.

Data Availability: The complete version of the research instrument is available from the second author.
Minimum inhibitory concentrations of cephalosporin compounds and their active metabolites for selected mastitis pathogens
Authors: Cortinhas Cristina S. , Oliveira Leane , Hulland Carol A. , Santos Marcos V. , Ruegg Pamela L.
Published: April 2013

Objective—To compare the minimum inhibitory concentration (MIC) of cephapirin and ceftiofur with MICs of their active metabolites (desacetylcephapirin and desfuroylceftiofur) for selected mastitis pathogens.

Sample—488 mastitis pathogen isolates from clinically and subclinically affected cows in commercial dairy herds in Wisconsin.

Procedures—Agar dilution was used to determine MICs for Staphylococcus aureus (n = 98), coagulase-negative staphylococci (99), Streptococcus dysgalactiae (97), Streptococcus uberis (96), and Escherichia coli (98).

Results—All S aureus isolates were susceptible to cephapirin and ceftiofur. Most coagulase-negative staphylococci were susceptible to cephapirin and ceftiofur. For E coli, 50 (51.0%; cephapirin) and 93 (94.95%; ceftiofur) isolates were susceptible to the parent compounds, but 88 (89.8%) were not inhibited at the maximum concentration of desacetylcephapirin. All S dysgalactiae isolates were susceptible to ceftiofur and cephapirin, and consistent MICs were obtained for all compounds. Most S uberis isolates were susceptible to cephapirin and ceftiofur. Of 98 S aureus isolates classified as susceptible to ceftiofur, 42 (42.9%) and 51 (52%) were categorized as intermediate or resistant to desfuroylceftiofur, respectively. For 99 coagulase-negative staphylococci classified as susceptible to ceftiofur, 45 (45.5%) and 17 (17.2%) isolates were categorized as intermediate or resistant to desfuroylceftiofur, respectively. For all staphylococci and streptococci, 100% agreement in cross-classified susceptibility outcomes was detected between cephapirin and desacetylcephapirin. No E coli isolates were classified as susceptible to desacetylcephapirin.

Conclusions and Clinical Relevance—Differences in inhibition between parent compounds and their active metabolites may be responsible for some of the variation between clinical outcomes and results of in vitro susceptibility tests.
Medial femoral condyle morphometrics and subchondral bone density patterns in Thoroughbred racehorses
Authors: Walker Wade T. , Kawcak Christopher E. , Hill Ashley E.
Published: April 2013

Objective—To characterize medial femoral condyle (MFC) morphometrics and subchondral bone density patterns in Thoroughbred racehorses and to determine whether these variables differ between left and right limbs.

Sample—Stifle joints harvested from 6 Thoroughbred racehorses euthanized for reasons other than hind limb lameness.

Procedures—The distal portion of the left and right femurs of each cadaver was scanned via CT. Hounsfield units were converted to dipotassium phosphate equivalent densities through use of a phantom on each specimen. Medial femoral condyle width, length, height, and curvature; subchondral bone plate densities; and subchondral trabecular bone densities were analyzed in multiple sections in 5 frontal planes and 3 sagittal planes and were compared between left and right MFCs.

Results—MFC width, length, and height did not differ between left and right limbs. Regions of interest in the right caudoaxial subchondral bone plate and subchondral trabecular bone were significantly denser than their corresponding left regions of interest in the frontal and sagittal planes. A concavity in the otherwise convex articular surface of the cranial aspect of the MFC was identified in 11 of 12 specimens.

Conclusions and Clinical Relevance—A disparity was identified between left and right subchondral bone density patterns at the caudoaxial aspect of the MFC, which could be attributable to the repetitive asymmetric cyclic loading that North American Thoroughbred racehorses undergo as they race in a counterclockwise direction. The uneven region at the cranial aspect of the MFC could be associated with the development of subchondral bone cysts in horses.