bluuebunny/crossref_metadata_2025 huggingface dataset:
The single‐subunit RING‐type E3 ubiquitin ligase RSL1 targets PYL4 and PYR1 ABA receptors in plasma membrane to modulate abscisic acid signaling
Authors: Bueso Eduardo , Rodriguez Lesia , Lorenzo‐Orts Laura , Gonzalez‐Guzman Miguel , Sayas Enric , Muñoz‐Bertomeu Jesús , Ibañez Carla , Serrano Ramón , Rodriguez Pedro L.
Published: October 2014

Membrane‐delimited events play a crucial role for ABA signaling and PYR/PYL/RCAR ABA receptors, clade A PP2Cs and SnRK2/CPK kinases modulate the activity of different plasma membrane components involved in ABA action. Therefore, the turnover of PYR/PYL/RCARs in the proximity of plasma membrane might be a step that affects receptor function and downstream signaling. In this study we describe a single‐subunit RING‐type E3 ubiquitin ligase RSL1 that interacts with the PYL4 and PYR1 ABA receptors at the plasma membrane. Overexpression of RSL1 reduces ABA sensitivity and rsl1 RNAi lines that impair expression of several members of the RSL1/RFA gene family show enhanced sensitivity to ABA. RSL1 bears a C‐terminal transmembrane domain that targets the E3 ligase to plasma membrane. Accordingly, bimolecular fluorescent complementation (BiFC) studies showed the RSL1–PYL4 and RSL1–PYR1 interaction is localized to plasma membrane. RSL1 promoted PYL4 and PYR1 degradation in vivo and mediated in vitro ubiquitylation of the receptors. Taken together, these results suggest ubiquitylation of ABA receptors at plasma membrane is a process that might affect their function via effect on their half‐life, protein interactions or trafficking.
Is undertransfusion a problem in modern clinical practice?
Authors: Hibbs Stephen , Miles David , Staves Julie , Murphy Michael F.
Published: October 2014

Background

Significant progress has been made in reducing inappropriate transfusion of blood products. However, there is also a need to monitor for their underutilization in patients who would benefit from transfusion. This study aimed to develop a method to monitor for undertransfusion and conduct a preliminary examination of whether it is a problem in modern clinical practice.

Study Design and Methods

All patients with a hemoglobin (Hb) concentration below 6 g/dL or platelet (PLT) count of fewer than 10 × 109/L were identified during a 1‐month period in an academic medical center in the United Kingdom. Patients who were transfused within 72 hours of the low reading were excluded from further analysis. For all other patients, records were examined against predefined criteria to ascertain whether the reason for nonadministration of transfusion was justified.

Results

During the study period there were 63 eligible Hb readings and 130 eligible PLT counts in 93 patients. Of these, 36 patients were not transfused within 72 hours of the low reading. The majority of nonadministration (n = 28) was justified by either an additional Hb or an additional PLT count on repeat sampling being above the transfusion threshold or the transfusion being medically inappropriate. No documentation was found to indicate that any cases of nonadministration of blood were unjustified.

Conclusion

This study did not find that patients with low Hb readings or PLT counts were inappropriately undertransfused. However, systems similar to those described in this study should be developed to monitor for inappropriate undertransfusion as well as continuing efforts to monitor for and reduce inappropriate overtransfusion.
A novel immune competent murine hypertrophic scar contracture model: A tool to elucidate disease mechanism and develop new therapies
Authors: Ibrahim Mohamed Magdy , Bond Jennifer , Bergeron Andrew , Miller Kyle J. , Ehanire Tosan , Quiles Carlos , Lorden Elizabeth R. , Medina Manuel A. , Fisher Mark , Klitzman Bruce , Selim M. Angelica , Leong Kam W. , Levinson Howard
Published: October 2014

Hypertrophic scar (HSc) contraction following burn injury causes contractures. Contractures are painful and disfiguring. Current therapies are marginally effective. To study pathogenesis and develop new therapies, a murine model is needed. We have created a validated immune‐competent murine HSc model. A third‐degree burn was created on dorsum of C57BL/6 mice. Three days postburn, tissue was excised and grafted with ear skin. Graft contraction was analyzed and tissue harvested on different time points. Outcomes were compared with human condition to validate the model. To confirm graft survival, green fluorescent protein (GFP) mice were used, and histologic analysis was performed to differentiate between ear and back skin. Role of panniculus carnosus in contraction was analyzed. Cellularity was assessed with 4′,6‐diamidino‐2‐phenylindole. Collagen maturation was assessed with Picro‐sirius red. Mast cells were stained with Toluidine blue. Macrophages were detected with F4/80 immune. Vascularity was assessed with CD31 immune. RNA for contractile proteins was detected by quantitative real‐time polymerase chain reaction (qRT‐PCR). Elastic moduli of skin and scar tissue were analyzed using a microstrain analyzer. Grafts contracted to ∼45% of their original size by day 14 and maintained their size. Grafting of GFP mouse skin onto wild‐type mice, and analysis of dermal thickness and hair follicle density, confirmed graft survival. Interestingly, hair follicles disappeared after grafting and regenerated in ear skin configuration by day 30. Radiological analysis revealed that panniculus carnosus doesn't contribute to contraction. Microscopic analyses showed that grafts show increase in cellularity. Granulation tissue formed after day 3. Collagen analysis revealed increases in collagen maturation over time. CD31 stain revealed increased vascularity. Macrophages and mast cells were increased. qRT‐PCR showed up‐regulation of transforming growth factor beta, alpha smooth muscle actin, and rho‐associated protein kinase 2 in HSc. Tensile testing revealed that human skin and scar tissues are tougher than mouse skin and scar tissues.
Initial growth, refractive index, and crystallinity of thermal and plasma-enhanced atomic layer deposition AlN films
Authors: Van Bui Hao , Wiggers Frank B. , Gupta Anubha , Nguyen Minh D. , Aarnink Antonius A. I. , de Jong Michel P. , Kovalgin Alexey Y.
Published: October 2014

The authors have studied and compared the initial growth and properties of AlN films deposited on Si(111) by thermal and plasma-enhanced atomic layer deposition (ALD) using trimethylaluminum and either ammonia or a N2-H2 mixture as precursors. In-situ spectroscopic ellipsometry was employed to monitor the growth and measure the refractive index of the films during the deposition. The authors found that an incubation stage only occurred for thermal ALD. The linear growth for plasma-enhanced ALD (PEALD) started instantly from the beginning due to the higher nuclei density provided by the presence of plasma. The authors observed the evolution of the refractive index of AlN during the growth, which showed a rapid increase up to a thickness of about 30 nm followed by a saturation. Below this thickness, higher refractive index values were obtained for AlN films grown by PEALD, whereas above that the refractive index was slightly higher for thermal ALD films. X-ray diffraction characterization showed a wurtzite crystalline structure with a (101¯0) preferential orientation obtained for all the layers with a slightly better crystallinity for films grown by PEALD.
Cytoskeleton Protects from Stress and Aging
Authors: Ray L. Bryan
Published: October 2014

A transcription factor may promote longevity by stabilizing the actin cytoskeleton in nematodes.
ROS to the Rescue!
Authors: VanHook Annalisa M.
Published: October 2014

Epidermal wounding triggers the production of mitochondrial reactive oxygen species that promote cytoskeletal responses necessary for healing.
LTX-109 Is a Novel Agent for Nasal Decolonization of Methicillin-Resistant and -Sensitive Staphylococcus aureus
Authors: Nilsson Anna C. , Janson Håkan , Wold Hedda , Fugelli Anders , Andersson Karin , Håkangård Camilla , Olsson Pernilla , Olsen Wenche Marie
Published: October 2014

Nasal decolonization has a proven effect on the prevention of severe
Staphylococcus aureus
infections and the control of methicillin-resistant
S. aureus
(MRSA). However, rising rates of resistance to antibiotics highlight the need for new substances for nasal decolonization. LTX-109 is a broad-spectrum, fast-acting bactericidal antimicrobial drug for topical treatment, which causes membrane disruption and cell lysis. This mechanism of action is not associated with cross-resistance and has a low propensity for development of resistance. In the present study, persistent nasal MRSA and methicillin-sensitive
S. aureus
(MSSA) carriers were treated for 3 days with vehicle or with 1%, 2%, or 5% LTX-109. A significant effect on nasal decolonization was observed already after 2 days of LTX-109 treatment in subjects treated with 2% or 5% LTX-109 compared to vehicle (
P
≤ 0.0012 by Dunnett′s test). No safety issues were noted during the 9-week follow-up period. Minimal reversible epithelial lesions were observed in the nasal cavity. The systemic exposure was very low, with a maximum concentration of drug in plasma (
C
max
) at 1 to 2 h postdosing (3.72 to 11.7 ng/ml). One week after treatment initiation, LTX-109 was not detectable in any subject. Intranasal treatment of
S. aureus
with LTX-109 is safe and reduces the bacterial load already after a single day of treatment. Hence, LTX-109 has potential as a new and effective antimicrobial agent with a low propensity of resistance development that can prevent infections by MSSA/MRSA during hospitalization. (This study has been registered at
ClinicalTrials.gov
under registration no. NCT01158235.)
Contribution of the Nitroimidazoles PA-824 and TBA-354 to the Activity of Novel Regimens in Murine Models of Tuberculosis
Authors: Tasneen Rokeya , Williams Kathy , Amoabeng Opokua , Minkowski Austin , Mdluli Khisimuzi E. , Upton Anna M. , Nuermberger Eric L.
Published: October 2014

New regimens based on two or more novel agents are sought in order to shorten or simplify the treatment of both drug-susceptible and drug-resistant forms of tuberculosis. PA-824 is a nitroimidazo-oxazine now in phase II trials and has shown significant early bactericidal activity alone and in combination with the newly approved agent bedaquiline or with pyrazinamide with or without moxifloxacin. While the development of PA-824 continues, a potential next-generation derivative, TBA-354, has been discovered to have
in vitro
potency superior to that of PA-824 and greater metabolic stability than that of the other nitroimidazole derivative in clinical development, delamanid. In the present study, we compared the activities of PA-824 and TBA-354 as monotherapies in murine models of the initial intensive and continuation phases of treatment, as well as in combination with bedaquiline plus pyrazinamide, sutezolid, and/or clofazimine. The monotherapy studies demonstrated that TBA-354 is 5 to 10 times more potent than PA-824, but selected mutants are cross-resistant to PA-824 and delamanid. The combination studies revealed that TBA-354 is 2 to 4 times more potent than PA-824 when combined with bedaquiline, and when administered at a dose equivalent to that of PA-824, TBA-354 demonstrated superior sterilizing efficacy. Perhaps most importantly, the addition of either nitroimidazole significantly improved the sterilizing activities of bedaquiline and sutezolid, with or without pyrazinamide, confirming the value of each agent in this potentially universally active short-course regimen.
Severe Langerhans cell histiocytosis in an infant: haemophagocytic syndrome association
Authors: Póvoas Marta Isabel , Luís Pedro Pereira , Esteves Isabel , Ferrão Anabela
Published: October 2014

Langerhans cell histiocytosis (LCH) is a rare disease of unknown origin with a heterogeneous clinical presentation, varying from benign and self-limited to lethal. It is classified as single or multisystemic, according to the number of organs involved (one or at least two, respectively). Diagnosis can be challenging and is based on the histological and immunophenotypic examination of affected tissues. Secondary haemophagocytic lymphohistiocytosis is rarely reported in association with LCH and may impair its diagnosis. Some authors suggest that the coexistence of the two disorders is more than coincidental. We present a case of multisystem LCH in a 5-month-old infant, with all risk organs involved, in which severity and rapid progression reflect an association with haemophagocytic syndrome.
Does long-term use of proton pump inhibitors cause hypomagnesaemia in Japanese outpatients?
Authors: Takeda Yasuhito , Doyama Hisashi , Tsuji Kunihiro , Yamada Shinya , Takemura Kenichi
Published: October 2014

Aim

Hypomagnesaemia has been reported associated with long-term proton pump inhibitor (PPI) treatment. However, there have been no studies in Japanese patients. We therefore assessed the effects of long-term PPI use on serum magnesium concentrations in Japanese patients.

Methods

Data from 481 outpatients who visited our centre in October and November 2011 were reviewed to determine their underlying diseases, oral medications, including PPIs, and serum magnesium concentrations. The association between PPI use and serum Mg concentrations was assessed by multiple linear regression analysis.

Results

Serum magnesium concentrations were significantly lower in PPI users (n=199) than in PPI non-users (n=282; 1.86±0.21 vs 1.91±0.19 mg/dL, p<0.01). Multiple linear regression analysis showed that the presence or absence of cirrhosis and PPI use was a significant predictor of magnesium concentration. In evaluating magnesium concentrations among PPI users and non-users with and without cirrhosis, we found that mean serum magnesium concentrations in patients with cirrhosis were significantly lower in PPI users than non-users (1.78±0.22 vs 1.87±0.22 mg/dL, p=0.03).

Conclusions

Outpatients receiving long-term PPI treatment had significantly lower serum magnesium concentrations than those not treated with PPI. To the best of our knowledge, this study is the first to show hypomagnesaemia in Japanese patients with cirrhosis receiving long-term PPI treatment.
HCV seropositivity in inmates and in the general population: an averaging approach to establish priority prevention interventions
Authors: Roux P , Sagaon-Teyssier L , Lions C , Fugon L , Verger P , Carrieri M P
Published: October 2014

Objectives

Despite the fact that a considerable portion of hepatitis C virus (HCV) positive individuals are viraemic, the risk of transmitting HCV to others is context dependent. Prison is a particularly risky environment as HCV prevention tools are often unavailable. Using data from a cross-sectional study conducted in centres for HCV testing in southeastern France, we aimed to compare the patterns of risk factors in HCV-positive inmates with those in the general population.

Setting

26 centres for HIV/HCV testing in southeastern France (23 in the general population and 3 in prison).

Primary outcome measure

HCV seropositivity measured with ELISA test.

Methods

A propensity score method to ensure that the general and inmate populations could be compared and a multimodel averaging to estimate the degree (strong, weak, none) of the association of a number of specific factors with HCV seropositivity in each group.

Results

Among the 52 082 participants, HCV infection prevalence was 1.5% and 5.2% in the general (n=46 125) and inmate (n=5957) populations, respectively. In both populations, ‘drug injection without snorting’ and ‘drug injection with snorting’ were very strongly associated with HCV seropositivity. Among inmates, ‘drug snorting alone’ (OR (95% CI) 2.21 (1.39 to 3.52) was also a strong correlate while tattoos, piercings (OR (95% CI) 1.22 (0.92 to 1.61)) and the sharing of toiletry items (OR (95% CI) 1.44 (0.84 to 2.47)) were weak correlates.

Conclusions

The pattern of risk factors associated with HCV seropositivity is different between the general and prison populations, injection and snorting practices being more prevalent in the latter. Access to prevention measures in prisons is not only a public health issue but also a human right for inmates who deserve equity of care and prevention.
Optically active helical polyethers from chiral terminal epoxides with a diarylamino group
Authors: Zhang Jin , Zhao Chun-Hui , Yang Li-Wen , Yang Nian-Fa
Published: October 2014

Six optically active epoxy propanes with a diarylamino group at the 3-position carbon were synthesized and polymerized. Poly((S)-3-diphenylaminopropene oxide) ([Formula: see text] = –634°) was obtained from the polymerization of (S)-3-diphenylaminopropene oxide ([Formula: see text] = +75°). By investigating chiroptical properties of the obtained polyethers derived from optically active epoxy propanes, we found that if the diarylamino group were rigid enough, the obtained polyethers from chiral terminal epoxides with a diarylamino group could maintain a one-handed helical conformation in solution.
A combined kinetic and computational study of the reactions of transient germylenes with oxiranes and thiiranes in solution
Authors: Kostina Svetlana S. , Leigh William J.
Published: October 2014

The reactions of dimethyl- and diphenylgermylene (GeMe2and GePh2, respectively) with cyclohexene oxide (CHO) and propylene sulfide (PrS) have been studied in hydrocarbon solvents at 25 °C by laser flash and steady-state photolysis methods using appropriately substituted germacyclopent-3-ene derivatives as germylene precursors. GeMe2reacts with CHO and PrS with rate constants in the range of 1.2–1.7 × 1010M−1s−1in hexanes at 25 °C to form new transient products that are assigned to the corresponding Lewis acid-base complexes of the germylene with the substrates. The complexation reactions were found to be reversible and are characterized by equilibrium constants of KC= (3.7 ± 0.8) × 103M−1and (3 ± 1) × 104M−1for complexation of GeMe2with CHO and PrS, respectively. The complexes decay over approximately 10 μs with the concomitant formation of tetramethyldigermene (Ge2Me4), identifiable by its characteristic UV-vis spectrum centered at λmax= 370 nm. Diphenylgermylene behaves analogously, reacting rapidly and reversibly with the two substrates to form the corresponding Lewis acid-base complexes (λmax≈ 355 nm) that decay over several tens of microseconds with the concomitant growth of the characteristic UV-vis spectrum of tetraphenyldigermene (Ge2Ph4) (λmax= 440 nm). Steady-state photolysis of the germylene precursors in the presence of CHO afforded germanium-containing oligomers but showed no evidence of oxygen abstraction or the formation of substrate-derived product(s). Similar photolyses in the presence of PrS also afforded germanium-containing oligomers, but as well yielded propene in 20%–30% yield and (in the case of the GePh2precursor) minor amounts of low molecular weight compounds that appear to be derived from the corresponding germanethione. Density functional theory calculations of the chalcogen abstraction reactions of GeMe2with oxirane and thiirane in the gas phase have been carried out at the B3LYP/6-311+G(d,p) level of theory and are in good qualitative agreement with the experimental data.
Bayesian posterior prediction of the patchy spatial distributions of small pelagic fish in regions of suitable habitat
Authors: Boyd Charlotte , Woillez Mathieu , Bertrand Sophie , Castillo Ramiro , Bertrand Arnaud , Punt André E.
Published: October 2014

Small pelagic fish aggregate within areas of suitable habitat to form patchy distributions with localized peaks in abundance. This presents challenges for geostatistical methods designed to investigate the processes underpinning the spatial distribution of stocks and simulate distributions for further analysis. In two-stage models, presence–absence is treated as separable and independent from the process explaining nonzero densities. This is appropriate where gaps in the distribution are attributable to one process and conditional abundance to another, but less so where patchiness is attributable primarily to the strong schooling tendencies of small pelagic fish within suitable habitat. We therefore developed a new modelling framework based on a truncated Gaussian random field (GRF) within a Bayesian framework. We evaluated this method using simulated test data and then applied it to acoustic survey data for Peruvian anchoveta (Engraulis ringens). We assessed the method’s performance in terms of posterior densities of spatial parameters, and the density distribution, spatial pattern, and overall spatial distribution of posterior predictions. We conclude that Bayesian posterior prediction based on a truncated GRF is effective at reproducing the patchiness of the observed spatial distribution of anchoveta.
On the growth of directed complex networks with preferential attachment: Effect upon the prohibition of multiple links
Authors: Esquivel-Gómez J. , Balderas-Navarro R. E. , Ugalde Edgardo , Acosta-Elías J.
Published: October 2014

Several real-world directed networks do not have multiple links. For example, in a paper citation network a paper does not cite two identical references, and in a network of friends there exists only a single link between two individuals. This suggest that the growth and evolution models of complex networks should take into account such feature in order to approximate the topological properties of this class of networks. The aim of this paper is to propose a growth model of directed complex networks that takes into account the prohibition of the existence multiple links. It is shown through numerical experiments that when multiple links are forbidden, the exponent γ of the in-degree connectivity distribution, [Formula: see text], takes values ranging from 1 to ∞. In particular, the proposed multi-link free (MLF) model is able to predict exponents occurring in real-world complex networks, which range 1.05 < γ < 3.51. As an example, the MLF reproduces somxe topological properties exhibited by the network of flights between airports of the world (NFAW); i.e. γ ≈ 1.74. With this result, we believe that the multiple links prohibition might be one of the local processes accounting for the existence of exponents γ < 2 found in some real complex networks.
A thermostatistical approach to scale-free networks
Authors: da Cruz João P. , Araújo Nuno A. M. , Raischel Frank , Lind Pedro G.
Published: October 2014

We describe an ensemble of growing scale-free networks in an equilibrium framework, providing insight into why the exponent of empirical scale-free networks in nature is typically robust. In an analogy to thermostatistics, to describe the canonical and microcanonical ensembles, we introduce a functional, whose maximum corresponds to a scale-free configuration. We then identify the equivalents to energy, Zeroth-law, entropy and heat capacity for scale-free networks. Discussing the merging of scale-free networks, we also establish an exact relation to predict their final "equilibrium" degree exponent. All analytic results are complemented with Monte Carlo simulations. Our approach illustrates the possibility to apply the tools of equilibrium statistical physics to study the properties of growing networks, and it also supports the recent arguments on the complementarity between equilibrium and nonequilibrium systems.
A Bi-Level Model to Estimate the US Air Travel Demand
Authors: Li Tao
Published: October 2014

A single-level optimization model (i.e., a Route Flow Estimator (RFE)) has been proposed to estimate the historical air travel demand. However, the RFE may require a significant amount of additional data collection effort when applied to estimate travel demand in small or medium-sized networks. We propose a novel bi-level model as an alternative to the RFE to handle demand estimation for small or medium-sized networks. The upper-level model is designed as a constrained least square (LS) model. The lower-level model is designed based on the RFE. The bi-level model estimates travel demand by considering travelers' choice behaviors and some observed data. It requires less data collection effort yet it produces estimation results consistent with those from the RFE. A Gauss–Seidel type (GST) algorithm is proposed to solve the bi-level model. To solve the upper-level model, we propose a heuristic algorithm, which is designed to solve the dual of the upper-level model. The estimation results from the two models are compared using two numerical examples: a small-sized example with one OD pair and a medium-sized example with 400 OD pairs.
Anomalous barrier escaping in an externally modulated environment of system-reservoir coupling
Authors: Wang Chun-Yang
Published: October 2014

The time-dependent barrier passage of an activated rate process is studied where the heat bath in the system-reservoir coupling environment is modulated by an external fluctuation. For a thorough inspection on the barrier recrossing dynamics, the Kramers rate and effective transmission coefficient are calculated of the reactive flux method. In the particular case of a δ-correlated noise activated Ornstein–Uhlenbeck process, it is found that, the external modulation can in some cases result in an maximum effective transmission coefficient. This reveals a maximum net flux and can be obtained from the minimum barrier recrossing resulted from appropriate external modulation.
Numerical Analysis on Phonon Localization of Vacancy Type Disordered Graphene
Authors: Islam Md. Sherajul , Rahaman Md. Tawabur , Bhuiyan Ashraful Ghani , Hashimoto Akihiro
Published: October 2014

The phonon properties of hydrogen passivated graphene with vacancy defects are studied using the forced vibrational method. The phonon density of states (PDOSs), typical mode patterns and localization length are calculated over a broad range of vacancies. We find that phonon properties of graphene strongly depend on the system size. We observe a broadening and softening of the PDOS peaks with the increase of vacancy concentrations. We find an increasing C – H stretching mode with the increase of defect density. Our numerical experiments reveal that the typical mode pattern for the K point in-plane TO (iTO) modes phonon show the spatial localized vibrations persuaded by vacancies, which are in conceptually good agreement with the large D band peak of the Raman spectra comes from the imperfections of crystal. For the K point iTO mode phonons, a typical localization length is on the order ≈ 5 nm for vacancy-type defects at high concentrations of 30% is observed. The localization effects manifest themselves in the projected temperature behavior of the constant-volume specific heat capacity of pristine and disordered graphene samples.
A Developed Local Polynomial Neuro-Fuzzy Model for Nonlinear System Identification
Authors: Abdollahzade Majid , Kazemi Reza
Published: October 2014

This paper proposes a local polynomial model tree (LPMT) learning technique for prediction and identification of nonlinear systems and processes. The proposed LPMT learning algorithm is applied to a local polynomial neuro fuzzy (LPNF) model, which includes local polynomial models (LPMs), as Taylor series expansion of any unknown function. . The LPMT algorithm is established based on the concept of hierarchical binary tree and heuristically partitions the input space into smaller subdomains through axis-orthogonal splits. The proposed learning algorithm starts from a single local polynomial model and then refines the LPNF model by increasing the degree of the worstperforming LPM or by further partitioning of the input space. During the learning procedure, the validity functions automatically form a partition of unity and therefore normalization side effects, e.g. reactivation and poor extrapolation performance, are prevented. The LPNF model, trained by the proposed LPMT algorithm, is used for prediction and identification of the nonlinear processes and systems in three case studies. The obtained results and comparisons to other methods revealed the promising performance of the proposed model.
ESTIMATING RESIDUAL HEDGING RISK WITH LEAST-SQUARES MONTE CARLO
Authors: ANKIRCHNER STEFAN , PIGORSCH CHRISTIAN , SCHWEIZER NIKOLAUS
Published: October 2014

Frequently, dynamic hedging strategies minimizing risk exposure are not given in closed form, but need to be approximated numerically. This makes it difficult to estimate residual hedging risk, also called basis risk, when only imperfect hedging instruments are at hand. We propose an easy to implement and computationally efficient least-squares Monte Carlo algorithm to estimate residual hedging risk. The algorithm approximates the variance minimal hedging strategy within general diffusion models. Moreover, the algorithm produces both high-biased and low-biased estimators for the residual hedging error variance, thus providing an intrinsic criterion for the quality of the approximation. In a number of examples we show that the algorithm delivers accurate hedging error characteristics within seconds.
Stability of stationary solutions for semilinear heat equations with concave nonlinearity
Authors: Akagi Goro , Kajikiya Ryuji
Published: October 2014

This paper is concerned with the stability analysis of stationary solutions of the Cauchy–Dirichlet problem for some semilinear heat equation with concave nonlinearity. The instability of sign-changing solutions is verified under some variational assumption. Moreover, the exponential stability of the positive stationary solution at an optimal rate is proved by exploiting a super–subsolution method as well as the parabolic regularity theory. The base of our analysis relies on the linearization of the equation at each stationary solution and spectral analysis of the corresponding linearized operator. The main difficulties reside in the singularity of the linearized operator due to the concave nonlinearity.
Evolution equations of p-Laplace type with absorption or source terms and measure data
Authors: Bidaut-Véron Marie-Françoise , Nguyen Quoc-Hung
Published: October 2014

Let Ω be a bounded domain of ℝN, and Q = Ω × (0, T). We consider problems of the type [Formula: see text] where Δpis the p-Laplacian, μ is a bounded Radon measure, u0∈ L1(Ω), and ±𝒢(u) is an absorption or a source term. In the model case 𝒢(u) = ±|u|q-1u (q > p-1), or 𝒢, has an exponential type. We prove the existence of renormalized solutions for any measure μ in the subcritical case, and give sufficient conditions for existence in the general case, when μ is good in time and satisfies suitable capacitary conditions.
A family of irreducible free divisors in ℙ2
Authors: Nanduri Ramakrishna
Published: October 2014

An infinite family of irreducible homogeneous free divisors in K[x, y, z] is constructed. Indeed, we identify sets of monomials X such that the general polynomial supported on X is a free divisor.
Degrees in Auslander–Reiten components with almost split sequences of at most two middle termss
Authors: Chaio Claudia
Published: October 2014

We consider A to be an artin algebra. We study the degrees of irreducible morphisms between modules in Auslander–Reiten components Γ having only almost split sequences with at most two indecomposable middle terms, that is, α(Γ) ≤ 2. We prove that if f : X → Y is an irreducible epimorphism of finite left degree with X or Y indecomposable, then there exists a module Z ∈ Γ and a morphism φ ∈ ℜn(Z, X)\ℜn+1(Z, X) for some positive integer n such that fφ = 0. In particular, for such components if A is a finite dimensional algebra over an algebraically closed field and f = (f1, f2)t : X → Y1 ⊕ Y2 is an irreducible epimorphism of finite left degree then we show that dl(f) = dl(f1) + dl(f2). We also characterize the artin algebras of finite representation type with α(ΓA) ≤ 2 in terms of a finite number of irreducible morphisms with finite degree.
Intersection algebras for principal monomial ideals in polynomial rings
Authors: Enescu Florian , Malec Sara
Published: October 2014

The properties of the intersection algebra of two principal monomial ideals in a polynomial ring are investigated in detail. Results are obtained regarding the Hilbert series and the canonical ideal of the intersection algebra using methods from the theory of Diophantine linear equations with integer coefficients.
Cohen–Macaulay graphs with large girth
Authors: Hoang Dô Trong , Minh Nguyên Công , Trung Trân Nam
Published: October 2014

We classify Cohen–Macaulay graphs of girth at least 5 and planar Gorenstein graphs of girth at least 4. Moreover, such graphs are also vertex decomposable.
NONLINEAR ANALYSIS OF VISCOELASTICALLY LAYERED ROLLS IN STEADY STATE ROLLING CONTACT
Authors: ABDEL RAHMAN ALAA A. , EL-SHAFEI AHMED G. , MAHMOUD FATIN F.
Published: October 2014

The present paper analyzes the steady state rolling contact (SSRC) response of nonlinear viscoelastically layered rigid roll indented by a rigid cylindrical indenter. Both material and geometrical nonlinearities are accounted for in the framework of the updated Lagrangian finite element formulation. The Schapery's viscoelastic creep model is adopted to model the viscoelastic behavior. To accommodate the steady state rolling condition, the constitutive equations are recast into a spatially dependent incremental form. Throughout the contact interface, the Lagrange multiplier method is used to enforce the contact constraints, while the classical Coulomb's law is adopted to simulate friction. The resulting nonlinear equilibrium equations are solved by the Newton–Raphson method. The developed model is applied to analyze a viscoelastically layered rigid roll in steady state rolling and intended by a rigid cylindrical indenter. Results showed the distinct effects of angular velocity, retardation time, indenter radius, and viscoelastic layer thickness on the SSRC configuration.
EXPLICIT SOLUTIONS FOR AN ANISOTROPIC PIEZOELECTRIC HALF-SPACE SUBJECT TO LINEARLY-VARYING SURFACE LOADINGS ALONG x3-DIRECTION
Authors: CHUNG M. Y.
Published: October 2014

Explicit results for a piezoelectric half-space x2≥ 0 subject to linearly-varying surface loadings along x3axis are derived. The extended Stroh formalism is employed to provide three-dimensional solutions with the generalized displacement vector u expressed as a function of (z, x2, x3). A general polynomial solution for u with order of m in x3is suggested and it provides a particularly efficient solution for half-space problem with loadings on the surface. A simple uniform surface loading is considered first to clarify the derivations. Then explicit solution in case of a linearly-varying surface loading along x3-direction is obtained. In addition, the Green's function for a piezoelectric half-space with a linearly-varying surface line loading along x3-axis is constructed.
Preparation of nanoporous graphene and the application of its nanocomposite membrane in propylene/propane separation
Authors: Sun Hai-Xiang , Yuan Bing-Bing , Li Peng , Wang Tao , Xu Yan-Yan
Published: October 2014

Chemically reduced graphene oxide containing hydroxyl groups and a wide size distribution of nanopores was prepared by a facile one-pot hydrothermal method. The resulting material was characterized by transmission electron microscopy (TEM), Raman spectroscopy, surface area measurement and attenuated total reflection infrared spectroscopy (ATR-FTIR), respectively. It was found that this reduced graphene oxide exhibited more clear nanopores and hydroxyl groups in the basal plane. Then the morphologies of the nanocomposite membrane incorporated into the nanoporous graphene were investigated through scanning electron microscopy (SEM), and the permeation test also was performed. Notably, the results showed that the nanocomposite membrane had a homogenous morphology and a better performance (separation factor 11.09) than polymer membrane in the separation of propylene/propane. This work demonstrates that nanoporous graphene exhibits great potential in the field of olefin/paraffin separation.
Uniform Bi2O2CO3 hierarchical nanoflowers: solvothermal synthesis and photocatalytic properties
Authors: Cao Feng , Wang Jianmin , Tu Wanhong , Lv Xin , Li Song , Qin Gaowu
Published: October 2014

Well-defined flowerlike Bi 2 O 2 CO 3 nanostructures were fabricated by a simple one-pot solvothermal method with high yield. The products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy, transmission electron microscopy, nitrogen sorption, photoluminescence spectra and UV–visible diffuse reflectance spectroscopy. The photocatalytic properties of the as-prepared samples were further investigated by photocatalytic decomposition of Rhodamine B (RhB) dye, and it was found that the Bi 2 O 2 CO 3 nanoflowers showed a good photocatalytic activity under UV light. The excellent photocatalytic performance of Bi 2 O 2 CO 3 flowerlike nanostructures is related to its special nanostructure and morphology, indicates its potential application in photocatalysis and nanosensors.
Talking to computers in natural language
Authors: Liang Percy
Published: October 2014

Natural language understanding is as old as computing itself, but recent advances in machine learning and the rising demand of natural-language interfaces make it a promising time to once again tackle the long-standing challenge.
Efficient digital neurons for large scale cortical architectures
Authors: Smith James E.
Published: October 2014

Digital neurons are implemented with the goal of sup-porting research and development of architectures which implement the computational paradigm of the neocortex.

Four spiking digital neurons are implemented at the register transfer level in a manner that permits side-by-side comparisons. Two of the neurons contain two stages of ex-ponential decay, one for synapse conductances and one for membrane potential. The other two neurons contain only one stage of exponential decay for membrane potential.

The two stage neurons respond to an input spike with a change in membrane potential that has a non-infinite lead-ing edge slope; the one stage neurons exhibit a change in membrane potential with an abrupt, infinite leading edge slope. This leads to a behavioral difference when a number of input spikes occur in very close time proximity. However, the one stage neurons are as much as a factor of ten more energy efficient than the two stage neurons, as measured by the number of dynamic add-equivalent operations

A new two stage neuron is proposed. This neuron reduc-es the number of decay components and implements decays in both stages via piece-wise linear approximation. Togeth-er, these simplifications yield two stage neuron behavior with energy efficiency that is only about a factor of two worse than the simplest one stage neuron.
Reducing access latency of MLC PCMs through line striping
Authors: Hoseinzadeh Morteza , Arjomand Mohammad , Sarbazi-Azad Hamid
Published: October 2014

Although phase change memory with multi-bit storage capability (known as MLC PCM) offers a good combination of high bit-density and non-volatility, its performance is severely impacted by the increased read/write latency. Regarding read operation, access latency increases almost linearly with respect to cell density (the number of bits stored in a cell). Since reads are latency critical, they can seriously impact system performance. This paper alleviates the problem of slow reads in the MLC PCM by exploiting a fundamental property of MLC devices: the Most-Significant Bit (MSB) of MLC cells can be read as fast as SLC cells, while reading the Least-Significant Bits (LSBs) is slower. We propose Striped PCM (SPCM), a memory architecture that leverages this property to keep MLC read latency in the order of SLC's. In order to avoid extra writes onto memory cells as a result of striping memory lines, the proposed design uses a pairing write queue to synchronize write-back requests associated with blocks that are paired in striping mode. Our evaluation shows that our design significantly improves the average memory access latency by more than 30% and IPC by up to 25% (10%, on average), with a slight overhead in memory energy (0.7%) in a 4-core CMP model running memory-intensive benchmarks
Fractal++
Authors: Voskuilen Gwendolyn , Vijaykumar T. N.
Published: October 2014

Cache coherence protocol bugs can cause multicores to fail. Existing coherence verification approaches incur state explosion at small scales or require considerable human effort. As protocols' complexity and multicores' core counts increase, verification continues to be a challenge. Recently, researchers proposed fractal coherence which achieves scalable verification by enforcing observational equivalence between sub-systems in the coherence protocol. A larger subsystem is verified implicitly if a smaller sub-system has been verified. Unfortunately, fractal protocols suffer from two fundamental limitations: (1) indirect-communication: sub-systems cannot directly communicate and (2) partially-serialinvalidations: cores must be invalidated in a specific, serial order. These limitations disallow common performance optimizations used by conventional directory protocols: replyforwarding where caches communicate directly and parallel invalidations. Therefore, fractal protocols lack performance scalability while directory protocols lack verification scalability. To enable both performance and verification scalability, we propose Fractal++ which employs a new class of protocol optimizations for verification-constrained architectures: decoupled-replies, contention-hints, and fully-parallel-fractal-invalidations. The first two optimizations allow reply-forwarding-like performance while the third optimization enables parallel invalidations in fractal protocols. Unlike conventional protocols, Fractal++ preserves observational equivalence and hence is scalably verifiable. In 32- core simulations of single- and four-socket systems, Fractal++ performs nearly as well as a directory protocol while providing scalable verifiability whereas the best-performing previous fractal protocol performs 8% on average and up to 26% worse with a single-socket and 12% on average and up to 34% worse with a longer-latency multi-socket system
Looking Back, Looking Ahead
Authors: Hill Jane H.
Published: October 2014

Much of my career has involved the reshaping and transformation of knowledge of language and history shared with me by indigenous people who had made it a life's project to acquire, remember, and pass on this heritage. A consideration of the meaning of these encounters is interwoven with an autobiography of my scholarly formation and research career, the role of generationally shaped good luck in this career, and what it taught me about how speakers in diverse circumstances exploit the structural resources of their languages to protect and advance their interests.
The Archaeology of Death: Mortuary Archaeology in the United States and Europe 1990–2013
Authors: Arnold Bettina , Jeske Robert J.
Published: October 2014

Mortuary archaeology has always been viewed as one of the most richly evocative sources of evidence for past social systems, particularly those without writing. However, the political context within which archaeology developed as a discipline, especially in countries with a colonial past, has made it difficult or impossible for the burial record to be utilized to its full potential. Ironically, this moratorium on the use of human remains for research purposes has been accompanied by the development of new analytical techniques, including ancient DNA (aDNA) and chemical analysis of skeletal material, which provide powerful tools for understanding complex social relationships and mobility within and between ancient populations. This review focuses on the United States and Europe because of the close relationship between their scholarly communities, as a result of which the limits placed on mortuary archaeology in the United States has had and continues to have a direct impact on the development of the discipline in numerous European countries. The inferential potential of bioarchaeology in particular is discussed against the backdrop of these sociohistorical developments, and the case studies presented highlight the powerful array of interdisciplinary approaches now being brought to bear on our understanding of ancient social systems.
Effective Field Theory Beyond the Standard Model
Authors: Willenbrock Scott , Zhang Cen
Published: October 2014

We review the effective field theory approach to physics beyond the Standard Model using dimension-six operators. Topics include the choice of operator basis, electroweak boson pair production, precision electroweak physics (including one-loop contributions), and Higgs physics. By measuring the coefficients of dimension-six operators with good accuracy, we can hope to infer some or all of the features of the theory that lies beyond the Standard Model.
Palaeoenvironment and Its Control on the Formation of Miocene Marine Source Rocks in the Qiongdongnan Basin, Northern South China Sea
Authors: Li Wenhao , Zhang Zhihuan , Wang Weiming , Lu Shuangfang , Li Youchuan , Fu Ning
Published: October 2014

The main factors of the developmental environment of marine source rocks in continental margin basins have their specificality. This realization, in return, has led to the recognition that the developmental environment and pattern of marine source rocks, especially for the source rocks in continental margin basins, are still controversial or poorly understood. Through the analysis of the trace elements and maceral data, the developmental environment of Miocene marine source rocks in the Qiongdongnan Basin is reconstructed, and the developmental patterns of the Miocene marine source rocks are established. This paper attempts to reveal the hydrocarbon potential of the Miocene marine source rocks in different environment and speculate the quality of source rocks in bathyal region of the continental slope without exploratory well. Our results highlight the palaeoenvironment and its control on the formation of Miocene marine source rocks in the Qiongdongnan Basin of the northern South China Sea and speculate the hydrocarbon potential of the source rocks in the bathyal region. This study provides a window for better understanding the main factors influencing the marine source rocks in the continental margin basins, including productivity, preservation conditions, and the input of terrestrial organic matter.
Small-Scale Effect on Longitudinal Wave Propagation in Laser-Excited Plates
Authors: Mirzade F. Kh.
Published: October 2014

Longitudinal wave propagation in an elastic isotopic laser-excited solid plate with atomic defect (vacancies, interstitials) generation is studied by the nonlocal continuum model. The nonlocal differential constitutive equations of Eringen are used in the formulations. The coupled governing equations for the dynamic of elastic displacement and atomic defect concentration fields are obtained. The frequency equations for the symmetrical and antisymmetrical motions of the plate are found and discussed. Explicit expressions for different characteristics of waves like phase velocity and attenuation (amplification) coefficients are derived. It is shown that coupling between the displacement and defect concentration fields affects the wave dispersion characteristics in the nonlocal elasticity. The dispersion curves of the elastic-diffusion instability are investigated for different pump parameters and larger wave numbers.