bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasmid-Encoded Pgp3 Is a Major Virulence Factor for Chlamydia muridarum To Induce Hydrosalpinx in Mice
Authors: Liu Yuanjun , Huang Yumeng , Yang Zhangsheng , Sun Yina , Gong Siqi , Hou Shuping , Chen Chaoqun , Li Zhongyu , Liu Quanzhong , Wu Yimou , Baseman Joel , Zhong Guangming
Published: October 2014

Hydrosalpinx induction in mice by
Chlamydia muridarum
infection, a model that has been used to study
C. trachomatis
pathogenesis in women, is known to depend on the cryptic plasmid that encodes eight genes designated
pgp1
to
pgp8
. To identify the plasmid-encoded pathogenic determinants, we evaluated
C. muridarum
transformants deficient in the plasmid-borne gene
pgp3
, -
4
, or -
7
for induction of hydrosalpinx.
C. muridarum
transformants with an in-frame deletion of either
pgp3
or -
4
but not -
7
failed to induce hydrosalpinx. The deletion mutant phenotype was reproduced by using transformants with premature termination codon insertions in the corresponding
pgp
genes (to minimize polar effects inherent in the deletion mutants). Pgp4 is known to regulate
pgp3
expression, while lack of Pgp3 does not significantly affect Pgp4 function. Thus, we conclude that Pgp3 is an effector virulence factor and that lack of Pgp3 may be responsible for the attenuation in
C. muridarum
pathogenicity described above. This attenuated pathogenicity was further correlated with a rapid decrease in chlamydial survival in the lower genital tract and reduced ascension to the upper genital tract in mice infected with
C. muridarum
deficient in Pgp3 but not Pgp7. The Pgp3-deficient
C. muridarum
organisms were also less invasive when delivered directly to the oviduct on day 7 after inoculation. These observations demonstrate that plasmid-encoded Pgp3 is required for
C. muridarum
survival in the mouse genital tract and represents a major virulence factor in
C. muridarum
pathogenesis in mice.
Emotionally-intense situations can result in rhabdomyolysis in McArdle disease
Authors: Brady Stefen , Godfrey Richard , Scalco Renata S , Quinlivan Ros M
Published: October 2014

Despite the majority of patients with McArdle disease reporting symptoms including fatigue, cramps and episodes of myoglobinuria from early childhood, diagnosis is often delayed by several decades. Additionally, many individuals with rhabdomyolysis remain undiagnosed. The occurrence of symptoms during exercise, particularly isometric muscle contraction such as heavy lifting, is well known in McArdle disease. However, isometric muscle contraction that occurs with emotion is not recognised as exercise and may be missed as a trigger for rhabdomyolysis, potentially leading to a delay in diagnosis. Three patients are presented here, all with symptoms from childhood including episodes of rhabdomyolysis induced by tense emotional situations without physical exertion; two patients reported recurrent episodes while watching rather than playing football. The remaining patient developed rhabdomyolysis during a heated argument. These patients’ histories emphasise the risk from sustained isometric muscle contraction that occurs in emotive situations for patients with McArdle disease.
An unusual diagnosis of splenic rupture
Authors: Roche Matthew , Maloku Fatmir , Abdel-Aziz Tarek Ezzat
Published: October 2014

A 22-year-old woman presented with a 3-day history of worsening epigastric pain, non-productive cough and vomiting. On examination she was pale and had abdominal tenderness predominant in the right upper quadrant. Abdominal ultrasound excluded the presence of gall stones, but was unable to rule out free fluid in the abdomen. CT demonstrated extensive high-density ascites; however, no source of bleeding could be demonstrated. Clinically the patient's condition deteriorated, and an exploratory laparotomy was performed. In theatre the splenic capsule was found to have detached from the splenic body and emergency splenectomy was performed. Virology serology later demonstrated acute cytomegalovirus (CMV) infection, although tissue microscopy and CMV staining were negative. No other cause of rupture was found. The interesting aspects of this case include the poor correlation between initial presenting symptoms and subsequent diagnosis, the difficulty encountered in making a firm diagnosis and the atypical cause of rupture.
Development and validation of a questionnaire (FASH—Functional Assessment Scale for Acute Hamstring Injuries): to measure the severity and impact of symptoms on function and sports ability in patients with acute hamstring injuries
Authors: Malliaropoulos Nikos , Korakakis Vasileios , Christodoulou Dimitris , Padhiar Nat , Pyne Debasish , Giakas Giannis , Nauck Tanja , Malliaras Peter , Lohrer Heinz
Published: October 2014

Objective

To develop a condition-specific patient-reported outcome measure, the Functional Assessment Scale for Acute Hamstring Injuries (FASH), de novo in three languages, following distinct and rigorous methodology for content generation, analysis and validation and to assess its psychometric properties.

Background

To our knowledge, there is no patient-reported functional scale specific for acute hamstring injuries.

Methods

The development of the scale followed specific guidelines, as well as de novo construction in three languages (Greek, English and German). Item generation was accomplished by selecting three different sources of items: literature review, focus group and key informant interviews. Content analysis was conducted by an expert committee. The 21 items selected as appropriate were tested through a structured content analytic method and item-content validity coefficient, and 10 were retained for the FASH. The validation and assessment of its psychometric properties followed theConsensus-based Standards for the selection of health status Measurement Instruments (COSMIN) recommendations to ensure quality, in a convenience sample of 140 participants.

Results

The face validity was adequate and tested by expert committees, authors and participants. Content validity was characterised as well addressed and conducted independently by experts and through specific content validation procedures. The dimensionality analysis indicated a one-factor solution explaining the 95.8% of total variance. Known group validity was demonstrated by significant differences between patients and controls (p<0.001). The FASH exhibited very good test–retest reliability (intraclass correlation coefficient=0.9, p<0.001), internal consistency (α=0.98) and responsiveness (3.81 and 5.23 using baseline and pooled SD, respectively; standardised response mean (SRD)=4.68).

Conclusion

This study provides initial evidence for psychometric properties of the first scale assessing hamstring injuries.
Bayesian estimation of cardiovascular autonomic neuropathy diagnostic test based on short-term heart rate variability without a gold standard
Authors: Tang Zi-Hui , Wang Lin , Zeng Fangfang , Li Zhongtao , Yu Xiaoling , Zhang Keqin , Zhou Linuo
Published: October 2014

Objective

To evaluate the reference values for short-term heart rate variability (HRV), estimate the performance of cardiovascular autonomic neuropathy (CAN) diagnostic tests in the absence of a gold standard, and assess CAN prevalence in our dataset.

Setting

Community and hospital health centre.

Participants

Of 2092 subjects available for data analysis, 371 healthy subjects were selected so the reference values for the short-term HRV test could be evaluated. An external dataset contained 88 subjects who completed both the short-term HRV test and Ewing's test.

Intervention

Collection of information on clinical outcome.

Primary and second outcome measures

Cardiovascular autonomic function evaluated by using the short-term HRV test and/or Ewing's test.

Results

Cut-off points of 356.13, 55.45 and 36.64 ms2were set for total power, low frequency and high frequency (HF), respectively. The diagnostic test for CAN based on the mentioned reference value was created. The HRV test had a high sensitivity (80.01–85.09%) and specificity (82.30–85.20%) for CAN. In addition, the non-inferiority test rejected the null hypothesis that the performance of the HRV test was inferior to that of Ewing's test (p<0.05). The estimated CAN prevalence was 14.92% and 29.17% in the total sample and patients with diabetes, respectively.

Conclusions

Our findings provided reference values for short-term HRV, which were used for the CAN diagnostic test with high sensitivity and specificity. The estimated CAN prevalence was high in the Chinese population.
Pain and pressure pain thresholds in adolescents with chronic fatigue syndrome and healthy controls: a cross-sectional study
Authors: Winger Anette , Kvarstein Gunnvald , Wyller Vegard Bruun , Sulheim Dag , Fagermoen Even , Småstuen Milada Cvancarova , Helseth Sølvi
Published: October 2014

Objectives

Although pain is a significant symptom in chronic fatigue syndrome (CFS), pain is poorly understood in adolescents with CFS. The aim of this study was to explore pain distribution and prevalence, pain intensity and its functional interference in everyday life, as well as pressure pain thresholds (PPT) in adolescents with CFS and compare this with a control group of healthy adolescents (HC).

Methods

This is a case–control, cross-sectional study on pain including 120 adolescents with CFS and 39 HCs, aged 12–18 years. We measured pain frequency, pain severity and pain interference using self-reporting questionnaires. PPT was measured using pressure algometry. Data were collected from March 2010 until October 2012 as part of the Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial.

Results

Adolescents with CFS had significantly lower PPTs compared with HCs (p<0.001). The Pain Severity Score and the Pain Interference Score were significantly higher in adolescents with CFS compared with HCs (p<0.001). Almost all adolescents with CFS experienced headache, abdominal pain and/or pain in muscles and joints. Moreover, in all sites, the pain intensity levels were significantly higher than in HCs (p<0.001).

Conclusions

We found a higher prevalence of severe pain among adolescents with CFS and lowered pain thresholds compared with HCs. The mechanisms, however, are still obscure. Large longitudinal population surveys are warranted measuring pain thresholds prior to the onset of CFS.

Trial registration number

Clinical Trials,NCT01040429; The Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial (NorCAPITAL)http://www.clinicaltrials.gov.
Speciation in North American water lilies: evidence for the hybrid origin of the newly discovered Canadian endemic Nymphaea loriana sp. nov. (Nymphaeaceae) in a past contact zone
Authors: Borsch Thomas , Wiersema John H. , Hellquist C. Barre , Löhne Cornelia , Govers Kim
Published: October 2014

Field observations of morphologically intermediate water lilies in central Canada suggested a hybrid origin involving the parents Nymphaea odorata Aiton and Nymphaea leibergii Morong despite the fertile nature of these plants. Sequencing of the nrITS and the plastid rps4–trnT–trnF regions further including all members of the north temperate Nymphaea subg. Nymphaea clade, and samples from other hybrids occurring in North America in the wild, allowed us to determine that individuals of N. leibergii and of N. odorata were the maternal and paternal parents, respectively. Hybrids of New England have all proven to be sterile, are genetically variable, and probably are F1. By comparison, the plants of east-central Saskatchewan and west-central Manitoba are fully fertile and genetically uniform based on ISSR and sequence data. On the basis of this evidence, the latter are here described as a new species, Nymphaea loriana sp. nov., which may have originated during the Holocene climatic optimum about 6000 years ago in a past contact zone of the parents. Further hybrids detected between N. odorata and Nymphaea tetragona Georgi, as well as between N. leibergii and N. tetragona, were always sterile. Gene trees of the temperate clade of Nymphaea converge on a clade of small-flowered water lilies (sect. Chamaenymphaea), including N. leibergii, N. tetragona, and Nymphaea pygmaea. Nuclear ITS further resolves an American clade (Nymphaea mexicana Zucc. – N. odorata) sister to all remaining species. This split into two major subclades also appears in the otherwise less resolved rps4–trnT–trnF tree. Thus the origin of N. loriana is a reticulation between long-separated parental lineages.
Plant community – soil relationships in a topographically diverse grassland in southern interior British Columbia, Canada
Authors: Lee Robert N. , Bradfield Gary E. , Krzic Maja , Newman Reg F. , Cumming W.F. Preston
Published: October 2014

The current management focus for many of British Columbia’s grasslands is on sustaining their high natural and economic values in light of concerns over climate change and spread of exotic species. To that end, scientific information on plant community – soil – topographic relationships is required to assist with the often complex decisions that managers face. We collected data on vegetation, topography, and soil properties at 38 sites over a range of elevation zones and aspects at Lac du Bois Grasslands Provincial Park near Kamloops, British Columbia. Cluster analysis of the vegetation data validated the current three-zonal system used for grazing management but indicated that boundaries between adjacent plant communities are interspersed according to aspect. Principal component analysis (PCA) of environmental variables identified a gradient from the less productive, lower grasslands (higher soil bulk density, bare soil, coarse fragment content), to the more productive, upper grasslands (higher litter cover, total soil C and aggregate stability). Projection of six exotic species functional groups into the PCA-environment space showed significant associations of winter annuals with the lower grasslands, versus perennials (both clonal reproducers and seed bankers) with the upper grasslands. Our analysis showed promise in identifying fine-scale linkages between plant community patterns and key environmental factors. This approach may be useful as part of a proactive management plan for maintaining the health of British Columbia grasslands.
Low reproductive success of hay-scented fern (Dennstaedtia punctilobula) regardless of inbreeding level or time since disturbance
Authors: Flinn Kathryn M. , Loiacono Matthew M. , Groff Hannah E.
Published: October 2014

Self-fertilization can facilitate the colonization of new habitats because it allows a single individual to found a population. Here we investigated the relationship between mating systems and colonization in hay-scented fern (Dennstaedtia punctilobula (Michx.) T.Moore). Throughout eastern North America, this species has been called a “native invasive” for its tendency to dominate forest understories disturbed by logging, inhibiting tree regeneration. Thus, it is important to understand the mechanisms of its spread. We hypothesized that if populations were founded through selfing, then populations disturbed more recently would retain higher selfing ability; this pattern would demonstrate an important link between mating systems and colonization. For four populations logged at different times in the past, we compared the sporophyte production of gametophytes at different levels of inbreeding (intragametophytic selfing, intergametophytic selfing, and outcrossing) using laboratory crosses. Across all treatments, only 9.8% of gametophytes formed sporophytes (N = 400 gametophytes). Neither inbreeding level nor time since disturbance affected sporophyte production. Selfing ability did not differ across populations logged at different times; there was no interaction between inbreeding level and time since disturbance. The low reproductive success of D. punctilobula, regardless of inbreeding level or time since disturbance, suggests that population establishment and expansion via sexual reproduction may be relatively rare in this clonal species.
The exact solutions of a (2 + 1)-dimensional Dirac oscillator under a magnetic field in the presence of a minimal length
Authors: Boumali Abdelmalek , Hassanabadi Hassan
Published: October 2014

Minimal length of a two-dimensional Dirac oscillator is investigated in the presence of a uniform magnetic field and illustrates the wave functions in the momentum space. The energy eigenvalues are found and the corresponding wave functions are calculated in terms of hypergeometric functions.
Understanding the unexpected suppression patterns at RHIC and LHC
Authors: Djordjevic Magdalena , Djordjevic Marko
Published: October 2014

Understanding properties of QCD matter created in ultra-relativistic heavy-ion collisions is a major goal of RHIC and LHC experiments. Suppression of light and heavy flavor observables is a powerful tool to understand these properties and the suppressions of underlying partons appear to suggest a clear hierarchy in the suppression of these observables. However, the measurements show significant qualitative differences between the observed and intuitively expected patterns, in particular for neutral pions and single electrons at RHIC and for charged hadrons and D mesons at LHC, which are denoted as heavy flavor puzzles at RHIC and LHC. In this review, we discuss these puzzles and also summarize evidence that they can be consistently explained within the same theoretical framework.
Volume independence for Yang–Mills fields on the twisted torus
Authors: García Pérez Margarita , González-Arroyo Antonio , Okawa Masanori
Published: October 2014

We review some recent results related to the notion of volume independence in SU (N) Yang–Mills theories. The topic is discussed in the context of gauge theories living on a d-dimensional torus with twisted boundary conditions. After a brief introduction reviewing the formalism for introducing gauge fields on a torus, we discuss how volume independence arises in perturbation theory. We show how, for appropriately chosen twist tensors, perturbative results to all orders in the 't Hooft coupling depend on a specific combination of the rank of the gauge group (N) and the periods of the torus (l), given by lN2/d, for d even. We discuss the well-known relation to noncommutative field theories and address certain threats to volume independence associated to the occurrence of tachyonic instabilities at one-loop order. We end by presenting some numerical results in 2+1 dimensions that extend these ideas to the nonperturbative domain.
Confinement on R3 × S1: Continuum and lattice
Authors: Ogilvie Michael C.
Published: October 2014

There has been substantial progress in understanding confinement in a class of four-dimensional SU(N) gauge theories using semiclassical methods. These models have one or more compact directions, and much of the analysis is based on the physics of finite temperature gauge theories. The topology R3 × S1 has been most often studied using a small compactification circumference L such that the running coupling g2(L) is small. The gauge action is modified by a double-trace Polyakov loop deformation term, or by the addition of periodic adjoint fermions. The additional terms act to preserve Z(N) symmetry and thus confinement. An area law for Wilson loops is induced by a monopole condensate. In the continuum, the string tension can be computed analytically from topological effects. Lattice models display similar behavior, but the theoretical analysis of topological effects is based on Abelian lattice duality rather than on semiclassical arguments. In both cases, the key step is reducing the low-energy symmetry group from SU(N) to the maximal Abelian subgroup U(1)N-1 while maintaining Z(N) symmetry.
Effects of the reflective scattering in hadron production at high energies
Authors: Troshin S. M. , Tyurin N. E.
Published: October 2014

A gradual transition to the reflecting scattering mode developing already at the LHC energies is affecting multiparticle production dynamics, in particular, relation of the centrality with the impact parameter values of pp-collisions. We discuss the issues in the framework of the geometrical picture for the multiparticle production processes proposed by Chou and Yang. We consider effects of reflective scattering mode presence for the inclusive cross-sections.
Shifted Fang–Howard wavefunction for the two-dimensional electron gas and application to MOSFETs
Authors: Zhou Zhang-Wei , Sun Jiu-Xun , Khan Muhammad Ammar
Published: October 2014

A modified Fang–Howard (FH) wavefunction with two parameters for two-dimensional electron gas is proposed. The modified wavefunction takes an extra parameter compared to FH wavefunction. The two parameters are determined by using the variational method to minimize the ground level; analytic approximate expressions are derived for the two parameters. It is shown that the finite barrier can lower energy level of electron gas; the wavefunction takes finite value at interface. This is more reasonable than the original Stern wavefunction. The new wavefunction is compared with previous wavefunction based on the rectangular-well approximation, and is applied to an ultra-thin gate oxide MOSFET. The calculated tunneling current-voltage curves are in good agreement with experimental data.
Connection of electron distributions with minima of harmonic spectra
Authors: Wu Yan , Ren Xianghe , Zhang Jingtao
Published: October 2014

Corresponding relation between the electron distributions and the harmonic minimum is established, by taking for example of the harmonic generation of the aligned CO 2 molecules in the highest-occupied-molecular-orbital (HOMO). We show that, as the polarization of the driving laser field rotates from parallel to perpendicular to the molecular axis, the harmonic yield first increases then decreases, and the location of the minimum in the harmonic spectrum moves to the higher energy region. These variations are connected with the electron distributions in the molecular orbital (MO) along the laser polarization of the driving laser field. Hence, by varying the laser polarization to scan, one can extract the overall electron distributions of the MOs from the generated harmonics.
Black hole thermodynamics
Authors: Carlip S.
Published: October 2014

The discovery in the early 1970s that black holes radiate as black bodies has radically affected our understanding of general relativity, and offered us some early hints about the nature of quantum gravity. In this paper, will review the discovery of black hole thermodynamics and summarize the many independent ways of obtaining the thermodynamic and (perhaps) statistical mechanical properties of black holes. I will then describe some of the remaining puzzles, including the nature of the quantum microstates, the problem of universality, and the information loss paradox.
DUPUYTREN'S CONTRACTURE: EMERGING INSIGHT INTO A VIKING DISEASE
Authors: Nunn Adam C. , Schreuder Fred B.
Published: October 2014

Dupuytren's disease is a fibroproliferative condition of the palm, with a predilection for men, which has affected Northern Europeans since the Viking conquests. Although strongly heritable, clear evidence exists for environmental factors that modify the underlying genetic risk, such as diabetes, heavy drinking, and smoking. Evidence also exists for epilepsy (probably due to treatment with certain anti-epileptic drugs), and Human Immunodeficiency Virus infection. Recent large studies have shown no relationship with manual labour or vibrating tools. Two theories have emerged regarding the pathogenic mechanism: the first attributes the aberrant healing process that characterises Dupuytren's to free radicals, generated as a result of microangiopathy, whereas the second cites a genetic tendency toward apoptosis-resistant myofibroblasts. Despite only one study demonstrating linkage, emerging data from genome-wide association studies highlight a series of single nucleotide polymorphisms near members of the Wnt signalling pathway, and transcriptional profiling studies have consistently identified certain components of the extracellular matrix.
LYTIC LESIONS OF DISTAL RADIUS IN CHILDREN: A RARE TUBERCULAR PRESENTATION
Authors: Agarwal Anil , Kant Kumar Shashi , Kumar Anubrat , Shaharyar Abbas , Verma Indreshwar , Suri Tarun
Published: October 2014

Introduction: We report the presentation, management, and outcome in five children with osteoarticular tuberculosis of distal radius.

Patients: Patients were recruited in a prospective study. All patients underwent an open biopsy, curettage and diagnosis confirmed by histopathological/microbiological examination. In cavitary lytic lesions, bone grafting was also undertaken. The multidrug anti-tubercular chemotherapy was given for one year.

Observations: Five patients were included in the study. The average follow-up post-completion chemotherapy was 34.8 months. Bony lesions presented as a poorly defined radiolucent lytic area in metaphysis, cavitary lytic lesions with or without sequestrum or spanned the physeal plate. At final follow-up, except for one case, a full pain free range of movements was achieved in all cases. Fibular graft was used in two cases with cavitary lesions and incorporated well in both cases.

Conclusions: Tuberculosis can involve the adjacent physis and can be multifocal. The presentation is usually lytic with minimal sclerosis. For smaller ill defined lesions, curettage and multidrug anti-tubercular chemotherapy results in excellent outcome. Cavitary lytic lesions should be bone grafted as there is a risk of pathological fractures.
A RARE COMBINATION: LOCKED VOLAR DISTAL RADIO-ULNAR JOINT DISLOCATION WITH ISOLATED VOLAR CAPSULE RUPTURE
Authors: Tang Chris Yuk Kwan , Cheung Jason Pui Yin , Fung Boris
Published: October 2014

Distal Radioulnar Joint (DRUJ) dislocation is a commonly missed injury. A high clinical suspicion is required as the dislocation may not be obvious in the conventional views of radiographs. Volar DRUJ dislocations are far less common than the dorsal ones. Since triangular fibrocartilage complex (TFCC) is the major stabilizer of DRUJ, it is common that the irreducible DRUJ dislocation is associated with TFCC tear. We report a patient who had irreducible volar DRUJ dislocation blocked by the volar lip of sigmoid notch, with only isolated volar capsule rupture.
AN ADJUSTABLE KIRCHNER WIRE FRAME TRACTION METHOD FOR THE TREATMENT OF DORSAL FRACTURE-DISLOCATION OF THE DISTAL INTERPHALANGEAL JOINT
Authors: Kobayashi Koichi , Fukasawa Katsuyasu
Published: October 2014

We applied an adjustable traction method which enables early range of motion exercise for the dorsal fracture-dislocation of the distal interphalangeal joint, and obtained satisfactory results. The reduction of comminuted fragments or depression of the joint is unnecessary using the traction method, because early exercise accelerates the remodelling of the injured soft tissue, followed by the development of joint stability. This traction mechanism is independent of the vector force of the traction applied due to the frame-structure construction. Our method makes it easy to adjust the traction force in millimetre increments of the glove-finger length, and has broad range of traction force. In cases where the dislocation is persistent even after strengthening the traction force, a transverse-transfixing Kirschner wire (K-wire) can be inserted to hold the reduction securely against subluxation.
Uniform asymptotic expansions for hypergeometric functions with large parameters IV
Authors: Farid Khwaja S. , Olde Daalhuis A. B.
Published: October 2014

In this paper, we obtain asymptotic expansions for the Gauss hypergeometric function [Formula: see text], where ej = 0, ± 1, j = 1, 2, 3, as |λ| → ∞. We complete the results of three previous publications [Uniform asymptotic expansions for hypergeometric functions with large parameters I, Anal. Appl. (Singap.) 1 (2003) 111–120; Uniform asymptotic expansions for hypergeometric functions with large parameters II, Anal. Appl. (Singap.) 1 (2003) 121–128; Uniform asymptotic expansions for hypergeometric functions with large parameters III, Anal. Appl. (Singap.) 8 (2010) 199–210], discuss all cases and, what is new, we consider now all critical values of z. For one case, the full details of the well-known Bleistein method are given, since a new technical detail is observed.
On Weakly s-Semipermutable Subgroups of Finite Groups
Authors: Tang Na , Li Xianhua
Published: October 2014

We prove that a finite group G is p-supersolvable or p-nilpotent if some subgroups of G are weakly s-semipermutable in G. Several earlier results are generalized.
Lexsegment Ideals Are Sequentially Cohen-Macaulay
Authors: Ishaq Muhammad
Published: October 2014

The associated primes of an arbitrary lexsegment ideal I ⊆ S=K[x1,…,xn] are determined. As application it is shown that S/I is a pretty clean module, therefore S/I is sequentially Cohen-Macaulay and satisfies Stanley's conjecture.
The q-Analog Klein Bottle Lie Algebra
Authors: Jiang Cuipo , Jiang Jingjing , Pei Yufeng
Published: October 2014

In this paper, we study an infinite-dimensional Lie algebra ℬq, called the q-analog Klein bottle Lie algebra. We show that ℬq is a finitely generated simple Lie algebra with a unique (up to scalars) symmetric invariant bilinear form. The derivation algebra and the universal central extension of ℬq are also determined.
Noetherian Dimension and Co-localization of Artinian Modules over Local Rings
Authors: Nhan Le Thanh , Chau Tran Do Minh
Published: October 2014

Let (R, 𝔪) be a Noetherian local ring. Denote by N-dim RA the Noetherian dimension of an Artinian R-module A. In this paper, we give some characterizations for the ring R to satisfy N-dim RA = dim (R/ Ann RA) for certain Artinian R-modules A. Then the existence of a co-localization compatible with Artinian R-modules is studied and it is shown that if it is compatible with local cohomologies of finitely generated modules, then the base ring is universally catenary and all of its formal fibers are Cohen-Macaulay.
AN APPROACH AND METHODOLOGY OF ENVIRONMENTAL RISK ASSESSMENT FOR STRATEGIC DECISION-MAKING
Authors: WU KAN-KAN , ZHANG LUO-PING , FANG QIN-HUA
Published: October 2014

Environmental Risk Assessment (ERA) is a powerful set of technical and analytical instruments for analyzing environmental impacts, and has found application in supporting Decision-Making Processes (DMPs) over the last two decades. However, there is no interrelated application of ERA in Strategic Decision-Making (SDM) processes, and no systematic research on the approaches and methods of ERA to support the processes of SDM. In this paper, a new approach and methodological system of ERA for SDM process is set up, and then applied to the Principal Coastal Functional Zoning (PCFZ) in Xiamen Bay, China, as a case study to verify the feasibility of the proposed approach and its methodology. The results show that the approach and methodology of ERA for SDM could integrate ERA into the entire SDM process, and thereby support the PCFZ directly. Furthermore, this approach avoids or mitigates against dire environmental risk that are sometimes introduced by the SDM processes.
Dynamic numerical simulation on grinding medium flow field for vibration mill under various vibrating amplitude–frequency combination conditions
Authors: Yang Xiaolan , Liu Jifeng , Zhang Xuan , Cheng Shangwei
Published: October 2014

People gained limited progress on refinement of super-hard powder using the vibration mill for many years. According to various amplitude–frequency combination working conditions of vibration mill prototype, simulation research on dynamic characteristic of grinding medium flow field based on PFC is proposed in the paper, and a dynamics model of grinding medium flow field in barrel is established. Furthermore, trajectory image of medium flow, kinetic energy and strain energy and collision frequency can be obtained. The simulation analysis shows that collision between media as well as between media and the barrel can cause the changes of kinetic energy and strain energy of grinding medium flow under various amplitude–frequency combination conditions, and an energy-lacking region exists in the barrel. Contrast experiments under various working conditions show that kinetic energy and strain energy of grinding medium flow have large increment and energy-lacking regions become smaller, and then energy consumption decreases on working condition of high-amplitude and middle-frequency. The conclusion has practical value to refine powder by high-intensity vibration mill with certain frequency.
AN ANALYSIS OF STOCK REPURCHASE TRANSACTION USING A PANEL DATA SAMPLE SELECTION MODEL
Authors: KUO CHII-SHYAN , YU SHIH-TI , LIAO CHE-CHING
Published: October 2014

Prior studies have examined repurchase decisions (i.e., whether to repurchase or not) and the determinants of repurchase amount (i.e., if yes, then how much is the repurchase amount), separately. However, this approach overlooks the fact that, in practice, firms most likely will take both decisions into consideration simultaneously. We argue that to ignore simultaneity features in repurchase decisions could lead to suspicious conclusions. In this study, we incorporate the two related decisions referenced above into a panel data sample selection model and analyze the determinants of stock repurchases. Further, we test whether managers make use of inside information in determining the timing of repurchases. We first find that the decision whether to repurchase is correlated with the decision of how much to repurchase. This finding supports the position that the omission of either decision when analyzing the data could lead to incorrect inferences. Second, we find cash, leverage, and market-to-book (MKBK) ratios are the most important factors related to firm repurchase transactions. More importantly, we find that leverage plays the key role in determining the dollar amount of repurchase. That is, financial structure is a firm's main concern when facing a repurchase decision. Third, we find that the larger the firm size is, the greater the amount of stocks firms will repurchase. Finally, we find that earnings shock plays no role in the decision to repurchase.
Incremental blind feedback
Authors: Paik Jiaul H. , Pal Dipasree , Parui Swapan K.
Published: October 2014

Automatic query expansion (AQE) is a useful technique for enhancing the effectiveness of information retrieval systems. In this article, we propose a novel AQE algorithm which first adopts a systematic incremental approach to choose feedback documents from the top retrieved set and then selects the expansion terms aggregating the scores from each feedback set. We also devise a term selection measure and a number of weighting schemes based on easily computable features. A set of experiments with a large number of standard test collections reveals that the proposed incremental blind feedback algorithm outperforms a number of state-of-the-art query expansion methods with remarkable significance and consistency.
Probabilistic modeling and analysis of molecular memory
Authors: Kumawat Renu , Sahula Vineet , Gaur Manoj S.
Published: October 2014

This article investigates the aspects of designing a nanocell based molecular memory. An empirical model for molecular device is developed, based on circuit behavior of nitro-substituted Oligo (Phynylene Ethynylene) molecule (OPE). This device model is subsequently used to design nanocell based 1-bit memory and verified using HSPICE. The approach is extended to train the nanocell for multibit storage capability using external voltage signals. It is observed that to successfully train a 2-bit molecular memory, the number of control signals should be approx. one-fourth of total number of nanoparticles. A computational framework is proposed to compute the probability of retrieving the stored data bits correctly, at the output terminal of the nanocell buffer. This nanocell configuration is simulated by systematically varying number of nanoparticles and molecular switches. It is observed that the probability of the existence of at least one path from input to output approaches close to unity with presence of 20 or more nanoparticles in a nanocell. During memory model validation, 1000 samples of 1-bit memory (consisting of 20 nanoparticles) were generated and verified for read and write operations. The model verification results obtained for this memory cell closely match those obtained using analytical solution of probabilistic graph model.
Ultra-low-leakage chip multiprocessor design with hybrid FinFET logic styles
Authors: Chen Xianmin , Jha Niraj K.
Published: October 2014

FinFET has begun replacing CMOS at the 22nm technology node because of its enhanced ability to mitigate short-channel effects. Although leakage power of FinFET logic gates is lower than their CMOS counterparts, it still contributes to a large part of total power consumption. In this article, we show how ultra-low-leakage FinFET chip multiprocessors (CMPs) can be designed using a hybrid logic style. This hybrid style exploits the ultra-low-leakage feature of asymmetric-workfunction shorted-gate (ASG) FinFETs and the high-performance feature of shorted-gate (SG) FinFETs. We explore the impact of the hybrid style at both the module and CMP levels. To do this, we have developed FinFET logic libraries targeted at SG and ASG logic gates, suitably characterized for various parameters of interest. We have also modified existing tools and created a framework to evaluate the hybrid designs of SRAMs, caches, and CMPs. Using the design with SG FinFETs as the baseline for comparison, our experimental results show that the hybrid style can reduce leakage power of execution units to as low as 10.6% of the baseline without hurting performance, that of SRAMs to between 21.5% and 4.8% of the baseline with 0%-8.3% delay overhead, and that of CMPs to 10.0% of the baseline with negligible performance degradation.
Efficient Discovery of Association Rules and Frequent Itemsets through Sampling with Tight Performance Guarantees
Authors: Riondato Matteo , Upfal Eli
Published: October 2014

The tasks of extracting (top-K) Frequent Itemsets (FIs) and Association Rules (ARs) are fundamental primitives in data mining and database applications. Exact algorithms for these problems exist and are widely used, but their running time is hindered by the need of scanning the entire dataset, possibly multiple times. High-quality approximations of FIs and ARs are sufficient for most practical uses. Sampling techniques can be used for fast discovery of approximate solutions, but works exploring this technique did not provide satisfactory performance guarantees on the quality of the approximation due to the difficulty of bounding the probability of under- or oversampling any one of an unknown number of frequent itemsets. We circumvent this issue by applying the statistical concept ofVapnik-Chervonenkis (VC) dimensionto develop a novel technique for providing tight bounds on the sample size that guarantees approximation of the (top-K) FIs and ARs within user-specified parameters. The resulting sample size is linearly dependent on the VC-dimension of a range space associated with the dataset. We analyze the VC-dimension of this range space and show that it is upper bounded by an easy-to-compute characteristic quantity of the dataset, thed-index, namely, the maximum integerdsuch that the dataset contains at leastdtransactions of length at leastdsuch that no one of them is a superset of or equal to another. We show that this bound is tight for a large class of datasets. The resulting sample size is a significant improvement over previous known results. We present an extensive experimental evaluation of our technique on real and artificial datasets, demonstrating the practicality of our methods, and showing that they achieve even higher quality approximations than what is guaranteed by the analysis.
A Join-Like Operator to Combine Data Cubes and Answer Queries from Multiple Data Cubes
Authors: Malvestuto Francesco M.
Published: October 2014

In order to answer a “joint” query from multiple data cubes, Pourabass and Shoshani [2007] distinguish the data cube on the measure of interest (called the “primary” data cube) from the other data cubes (called “proxy” data cubes) that are used to involve the dimensions (in the query) not in the primary data cube. They demonstrate in study cases that, if the measures of the primary and proxy data cubes are correlated, then the answer to a joint query is an accurate estimate of its true value. Needless to say, for two or more proxy data cubes, the result depends upon the way the primary and proxy data cubes are combined together; however, for certain combination schemes Pourabass and Shoshani provide a
sufficient condition
, that they call
proxy noncommonality
, for the invariance of the result.

In this article, we introduce: (1) a
merge
operator combining the contents of a primary data cube with the contents of a proxy data cube, (2)
merge expressions
for general combination schemes, and (3) an equivalence relation between merge expressions having the same pattern. Then, we prove that proxy noncommonality characterizes patterns for which every two merge expressions are equivalent. Moreover, we provide an efficient procedure for answering joint queries in the special case of
perfect
merge expressions. Finally, we show that our results apply to data cubes in which measures are obtained from unaggregated data using the aggregate functions SUM, COUNT, MAX, and MIN, and a lot more.
Designing Trusted Embedded Systems from Finite State Machines
Authors: Dunbar Carson , Qu Gang
Published: October 2014

Sequential components are crucial for a real-time embedded system as they control the system based on the system's current state and real life input. In this article, we explore the security and trust issues of sequential system design from the perspective of a finite state machine (FSM), which is the most popular model used to describe sequential systems. Specifically, we find that the traditional FSM synthesis procedure will introduce security risks and cannot guarantee trustworthiness in the implemented circuits. Indeed, we show that not only do there exist simple and effective ways to attack a sequential system, it is also possible to insert a hardware Trojan Horse into the design without introducing any significant design overhead. We then formally define the notion of trust in FSM and propose a novel approach to designing trusted circuits from the FSM specification. We demonstrate both our findings on the security threats and the effectiveness of our proposed method on Microelectronics Center of North Carolina (MCNC) sequential circuit benchmarks.
Linguistic analysis of non-ITG word reordering between language pairs with different word order typologies
Authors: Na Hwidong , Lee Jong-Hyeok
Published: October 2014

The Inversion Transduction Grammar (ITG) constraints have been widely used for word reordering in machine translation studies. They are, however, so restricted that some types of word reordering cannot be handled properly. We analyze three corpora between SVO and SOV languages: Chinese-Korean, English-Japanese, and English-Korean. In our analysis, sentences that require non-ITG word reordering are manually categorized. We also report the results for two quantitative measures that reveal the significance of non-ITG word reordering. In conclusion, we suggest that ITG constraints are insufficient to deal with word reordering in real situations.
Finding Robust Itemsets under Subsampling
Authors: Tatti Nikolaj , Moerchen Fabian , Calders Toon
Published: October 2014

Mining frequent patterns is plagued by the problem of pattern explosion, making pattern reduction techniques a key challenge in pattern mining. In this article we propose a novel theoretical framework for pattern reduction by measuring the robustness of a property of an itemset such as closedness or nonderivability. The robustness of a property is the probability that this property holds on random subsets of the original data. We study four properties, namely an itemset being closed, free, non-derivable, or totally shattered, and demonstrate how to compute the robustness analytically without actually sampling the data. Our concept of robustness has many advantages: Unlike statistical approaches for reducing patterns, we do not assume a null hypothesis or any noise model and, in contrast to noise-tolerant or approximate patterns, the robust patterns for a given property are always a subset of the patterns with this property. If the underlying property is monotonic then the measure is also monotonic, allowing us to efficiently mine robust itemsets. We further derive a parameter-free technique for ranking itemsets that can be used for top-
k
approaches. Our experiments demonstrate that we can successfully use the robustness measure to reduce the number of patterns and that ranking yields interesting itemsets.
Optimal Priority Assignment to Control Tasks
Authors: Mancuso Giulio M. , Bini Enrico , Pannocchia Gabriele
Published: October 2014

In embedded real-time systems, task priorities are often assigned to meet deadlines. However, in control tasks, a late completion of a task has no catastrophic consequence; rather, it has a quantifiable impact in the control performance achieved by the task.

In this article, we address the problem of determining the optimal assignment of priorities and periods of sampled-data control tasks that run over a shared computation unit. We show that the minimization of the overall cost can be performed efficiently using a branch and bound algorithm that can be further speeded up by allowing for a small degree of suboptimality. Detailed numerical simulations are presented to show the advantages of various branching alternatives, the overall algorithm effectiveness, and its scalability with the number of tasks.
Utility-Based Resource Overbooking for Cyber-Physical Systems
Authors: De Niz Dionisio , Wrage Lutz , Rowe Anthony , Rajkumar Ragunathan (Raj)
Published: October 2014

Traditional hard real-time scheduling algorithms require the use of the worst-case execution times to guarantee that deadlines will be met. Unfortunately, many algorithms with parameters derived from sensing the physical world suffer large variations in execution time, leading to pessimistic overall utilization, such as visual recognition tasks. In this article, we present ZS-QRAM, a scheduling approach that enables the use of flexible execution times and application-derived utility to tasks in order to maximize total system utility. In particular, we provide a detailed description of the algorithm, the formal proofs for its temporal protection, and a detailed, evaluation. Our evaluation uses the Utility Degradation Resilience (UDR) showing that ZS-QRAM is able to obtain 4× as much UDR as ZSRM, a previous overbooking approach, and almost 2× as much UDR as Rate-Monotonic with Period Transformation (RM/TP). We then evaluate a Linux kernel module implementation of our scheduler on an Unmanned Air Vehicle (UAV) platform. We show that, by using our approach, we are able to keep the tasks that render the most utility by degrading lower-utility ones even in the presence of highly dynamic execution times.
Opening Statement: Will computers out-compete us all?
Authors: Andersen Espen
Published: October 2014

To jumpstart this symposium, Espen Andersen describes the debate surrounding "technological singularity" and questions whether this is something that will happen---and if so, what the consequences might be.