bluuebunny/crossref_metadata_2025 huggingface dataset:
Switch or Funnel: How RND-Type Transport Systems Control Periplasmic Metal Homeostasis
Authors: Kim Eun-Hae , Nies Dietrich H. , McEvoy Megan M. , Rensing Christopher
Published: March 2011

Bacteria have evolved several transport mechanisms to maintain metal homeostasis and to detoxify the cell. One mechanism involves an RND (
r
esistance-
n
odulation-cell
d
ivision protein family)-driven tripartite protein complex to extrude a variety of toxic substrates to the extracellular milieu. These efflux systems are comprised of a central RND proton-substrate antiporter, a membrane fusion protein, and an outer membrane factor. The mechanism of substrate binding and subsequent efflux has yet to be elucidated. However, the resolution of recent protein crystal structures and genetic analyses of the components of the heavy-metal efflux family of RND proteins have allowed the developments of proposals for a substrate transport pathway. Here two models of substrate extrusion through RND protein complexes of the heavy-metal efflux protein family are described. The funnel model involves the shuttling of periplasmic substrate from the membrane fusion protein to the RND transporter and further on through the outer membrane factor to the extracellular space. Conversely, the switch model requires substrate binding to the membrane fusion protein, inducing a conformational change and creating an open-access state of the tripartite protein complex. The extrusion of periplasmic substrate bypasses the membrane fusion protein, enters the RND-transporter directly via its substrate-binding site, and is ultimately eliminated through the outer membrane channel. Evidence for and against the two models is described, and we propose that current data favor the switch model.
Characterization of the Salmonella enterica Serovar TyphimuriumydcIGene, Which Encodes a Conserved DNA Binding Protein Required for Full Acid Stress Resistance
Authors: Jennings Matthew E. , Quick Laura N. , Soni Anjali , Davis Richard R. , Crosby Kathleen , Ott C. Mark , Nickerson Cheryl A. , Wilson James W.
Published: March 2011

Salmonella entericaserovar Typhimurium possesses a stimulon of genes that are differentially regulated in response to conditions of low fluid shear force that increase bacterial virulence and alter other phenotypes. In this study, we show that a previously uncharacterized member of this stimulon,ydcIor STM1625, encodes a highly conserved DNA binding protein with related homologs present in a range of Gram-negative bacterial genera. Gene expression analysis shows thatydcIis expressed in different bacterial genera and is involved in its autoregulation inS. Typhimurium. We demonstrate that purified YdcI protein specifically binds a DNA probe consisting of its own promoter sequence. We constructed anS. Typhimurium ΔydcImutant strain and show that this strain is more sensitive to both organic and inorganic acid stress than is an isogenic WT strain, and this defect is complemented intrans. Moreover, our data indicate thatydcIis part of therpoSregulon related to stress resistance. TheS. Typhimurium ΔydcImutant was able to invade cultured cells to the same degree as the WT strain, but a strain in whichydcIexpression is induced invaded cells at a level 2.8 times higher than that of the WT. In addition, induction ofydcIexpression inS. Typhimurium resulted in the formation of a biofilm in stationary-phase cultures. These data indicate theydcIgene encodes a conserved DNA binding protein involved with aspects of prokaryotic biology related to stress resistance and possibly virulence.
Enzymatic and Functional Analysis of a Protein Phosphatase, Pph3, from Myxococcus xanthus
Authors: Kimura Yoshio , Mori Yumi , Ina Youhei , Takegawa Kaoru
Published: March 2011

A protein phosphatase, designated Pph3, from
Myxococcus xanthus
showed the enzymatic characteristics of PP2C-type serine/threonine protein phosphatases, which are metal ion-dependent, okadaic acid-insensitive protein phosphatases. The
pph3
mutant under starvation conditions formed immature fruiting bodies and reduced sporulation.
Role of the mar-sox-rob Regulon in Regulating Outer Membrane Porin Expression
Authors: Chubiz Lon M. , Rao Christopher V.
Published: March 2011

Multiple factors control the expression of the outer membrane porins OmpF and OmpC in
Escherichia coli
. In this work, we investigated the role of the
mar-sox-rob
regulon in regulating outer membrane porin expression in response to salicylate. We provide both genetic and physiological evidence that MarA and Rob can independently activate
micF
transcription in response to salicylate, leading to reduced OmpF expression. MarA was also found to repress OmpF expression through a MicF-independent pathway. In the case of OmpC, we found that its transcription was moderately increased in response to salicylate. However, this increase was independent of MarA and Rob. Finally, we found that the reduction in OmpF expression in a
tolC
mutant is due primarily to Rob. Collectively, this work further clarifies the coordinated role of MarA and Rob in regulating the expression of the outer membrane porins.
Non-Identity-Mediated CRISPR-Bacteriophage Interaction Mediated via the Csy and Cas3 Proteins
Authors: Cady Kyle C. , O'Toole George A.
Published: March 2011

Studies of the
Escherichia
,
Neisseria
,
Thermotoga
, and
Mycobacteria
c
lustered
r
egularly
i
nterspaced
s
hort
p
alindromic
r
epeat (CRISPR) subtypes have resulted in a model whereby CRISPRs function as a defense system against bacteriophage infection and conjugative plasmid transfer. In contrast, we previously showed that the
Yersinia
-subtype CRISPR region of
Pseudomonas aeruginosa
strain UCBPP-PA14 plays no detectable role in viral immunity but instead is required for bacteriophage DMS3-dependent inhibition of biofilm formation by
P. aeruginosa
. The goal of this study is to define the components of the
Yersinia
-subtype CRISPR region required to mediate this bacteriophage-host interaction. We show that the
Yersinia
-subtype-specific
C
RISPR-
as
sociated (Cas) proteins Csy4 and Csy2 are essential for small CRISPR RNA (crRNA) production
in vivo
, while the Csy1 and Csy3 proteins are not absolutely required for production of these small RNAs. Further, we present evidence that the core Cas protein Cas3 functions downstream of small crRNA production and that this protein requires functional HD (predicted phosphohydrolase) and DEXD/H (predicted helicase) domains to suppress biofilm formation in DMS3 lysogens. We also determined that only spacer 1, which is not identical to any region of the DMS3 genome, mediates the CRISPR-dependent loss of biofilm formation. Our evidence suggests that gene 42 of phage DMS3 (
DMS3-42
) is targeted by CRISPR2 spacer 1 and that this targeting tolerates multiple point mutations between the spacer and DMS3-42 target sequence. This work demonstrates how the interaction between
P. aeruginosa
strain UCBPP-PA14 and bacteriophage DMS3 can be used to further our understanding of the diverse roles of CRISPR system function in bacteria.
The CRISPR/Cas Immune System Is an Operon Regulated by LeuO, H-NS, and Leucine-Responsive Regulatory Protein in Salmonella enterica Serovar Typhi
Authors: Medina-Aparicio L. , Rebollar-Flores J. E. , Gallego-Hernández A. L. , Vázquez A. , Olvera L. , Gutiérrez-Ríos R. M. , Calva E. , Hernández-Lucas I.
Published: March 2011

Prokaryotes have developed multiple strategies to survive phage attack and invasive DNA. Recently, a novel genetic program denominated the CRISPR/Cas system was demonstrated to have a role in these biological processes providing genetic immunity. This defense mechanism is widespread in the
Archaea
and
Bacteria
, suggesting an ancient origin. In the last few years, progress has been made regarding the functionality of the CRISPR/Cas system; however, many basic aspects of the system remain unknown. For instance, there are few studies about the conditions and regulators involved in its transcriptional control. In this work, we analyzed the transcriptional organization of the CRISPR/Cas system as well as the positive and negative regulators involved in its genetic expression in
Salmonella enterica
serovar Typhi. The results obtained show that in
S
. Typhi the CRISPR/Cas system is a LeuO-dependent operon silenced by the global regulator LRP, in addition to the previously known nucleoid-associated protein H-NS; both LRP and H-NS bind upstream and downstream of the transcriptional start site of
casA.
In this study, relevant nucleotides of the
casA
regulatory region that mediate its LeuO transcriptional activation were identified. Interestingly, specific growth conditions (N-minimal medium) were found for the LeuO-independent expression of the CRISPR/Cas system in
S
. Typhi. Thus, our work provides evidence that there are multiple modulators involved in the genetic expression of this immune system in
S
. Typhi IMSS-1.
Return to sport following anterior cruciate ligament reconstruction surgery: a systematic review and meta-analysis of the state of play
Authors: Ardern Clare L , Webster Kate E , Taylor Nicholas F , Feller Julian A
Published: March 2011

Background

An athlete's intention to return to sport following anterior cruciate ligament (ACL) injury is a major indication for surgical intervention.

Purpose

The purpose of this review was to determine postoperative return-to-sport outcomes after ACL reconstruction surgery.

Study design

Meta-analysis and systematic review

Methods

Electronic databases including Medline, Embase, SPORTDiscus and CINAHL were searched from the earliest possible entry to April 2010. Studies were included that reported the number of patients returning to sports participation following ACL reconstruction surgery. The results were presented using the World Health Organization's International Classification of Functioning, Disability and Health as a framework and combined using proportion meta-analyses.

Results

Forty-eight studies evaluating 5770 participants at a mean follow-up of 41.5 months were included for review. Overall, 82% of participants had returned to some kind of sports participation, 63% had returned to their preinjury level of participation, and 44% had returned to competitive sport at final follow-up. Approximately 90% of participants achieved normal or nearly normal knee function when assessed postoperatively using impairment-based outcomes such as laxity and strength, and 85% when using activity-based outcomes such as the International Knee Documentation Committee knee evaluation form. Fear of reinjury was the most common reason cited for a postoperative reduction in or cessation of sports participation.

Conclusion

The relatively low rate of return to competitive sport despite the high rates of successful outcome in terms of knee impairment-based function suggests that other factors such as psychological factors may be contributing to return-to-sport outcomes.
Unusual morphological features of uterine leiomyomas treated with progestogens
Authors: Boyd Clinton , McCluggage W Glenn
Published: March 2011

Background

Uterine leiomyomas are extremely common in surgical pathology practice and in the vast majority there are no issues in diagnosis. Progestogens are widely prescribed drugs for a variety of indications, including abnormal uterine bleeding, and are often given to women with leiomyomas but the pathological features of leiomyomas treated with progestogens are poorly described.

Methods

We report the pathological features in eight cases of uterine leiomyomas in women who had been treated with oral progestogens or a progestogen-containing intrauterine device; all cases were received in consultation because the features raised concern for leiomyosarcoma, smooth muscle tumour of uncertain malignant potential or a benign leiomyoma with unusual features. Additionally, we reviewed a series of cases of uterine leiomyomas (n=99) in women who exhibited progestogenic effects in the endometrium.

Results

The morphological features in the consult cases, which were widespread and marked and which varied somewhat from case to case, included small and/or large areas of infarct-type necrosis (sometimes mimicking coagulative tumour cell necrosis) with surrounding increased cellularity, mitotic activity, nuclear pyknosis, cytoplasmic eosinophilia, epithelioid morphology, stromal oedema, haemorrhage, and myxoid change and infiltration by CD56 positive granulated lymphocytes. Sometimes the features resulted in an almost deciduoid appearance. Similar features were present to a minor degree in significant numbers of the additional series of cases.

Conclusions

Pathologists should be aware of these progestogen-associated features when reporting uterine leiomyomas whether or not the clinician has indicated that the woman is taking progestogens since otherwise a diagnosis of leiomyosarcoma or smooth muscle tumour of uncertain malignant potential may be rendered. Useful features in suggesting a benign leiomyoma, in addition to recognition of the morphological features described which, in combination, are characteristic of progestogens, are the lack of true nuclear atypia and the low mitotic activity away from the abnormal areas.
Examining the decline in lost-time claim rates across age groups in Ontario between 1991 and 2007
Authors: Breslin F Curtis , Smith Peter M , Moore Ian
Published: March 2011

Objectives

Given the tendency for young people to show elevated work injury rates, this study sought to examine trends in young worker and adult compensation claim rates in a Canadian province.

Methods

Workers' compensation records and labour force survey data from 1991 to 2007 were used to compute claim rates by age group. To examine the contribution of work-related factors to claim rates by age group, multivariate analyses included industry and job tenure.

Results

Descriptive analysis showed that age groups had different rates of declines over the time period. Multivariate analyses showed that claim rate declines for older adults were greatest prior to 1999. Young workers showed the largest declines after 1999. There was no indication that changes in industry or job tenure accounted for the trends in claim rates among older or younger workers.

Conclusions

This study is one of the first to show a convergence in youth and adult workers' compensation claims in a North American jurisdiction. Ruling out work-related factors increases the possibility that systemic interventions may have contributed to the convergence. This provides policy makers in occupational health and safety with empirical data to guide targeting of resources.
SMOOTH PATHS OF CONDITIONAL EXPECTATIONS
Authors: ANDRUCHOW ESTEBAN , LAROTONDA GABRIEL
Published: March 2011

Let [Formula: see text] be a von Neumann algebra with a finite trace τ, represented in [Formula: see text], and let [Formula: see text] be sub-algebras, for t in an interval I (0 ∈ I). Let [Formula: see text] be the unique τ-preserving conditional expectation. We say that the path t ↦ Et is smooth if for every [Formula: see text] and [Formula: see text], the map [Formula: see text] is continuously differentiable. This condition implies the existence of the derivative operator [Formula: see text] If this operator satisfies the additional boundedness condition, [Formula: see text] for any closed bounded subinterval J ⊂ I, and CJ > 0 a constant depending only on J, then the algebras [Formula: see text] are *-isomorphic. More precisely, there exists a curve [Formula: see text], t ∈ I of unital, *-preserving linear isomorphisms which intertwine the expectations, [Formula: see text] The curve Gt is weakly continuously differentiable. Moreover, the intertwining property in particular implies that Gt maps [Formula: see text] onto [Formula: see text]. We show that this restriction is a multiplicative isomorphism.
NORM AND ANTI-NORM INEQUALITIES FOR POSITIVE SEMI-DEFINITE MATRICES
Authors: BOURIN JEAN-CHRISTOPHE , HIAI FUMIO
Published: March 2011

Some subadditivity results involving symmetric (unitarily invariant) norms are obtained. For instance, if [Formula: see text] is a polynomial of degree m with non-negative coefficients, then, for all positive operators A, B and all symmetric norms, [Formula: see text] To give parallel superadditivity results, we investigate anti-norms, a class of functionals containing the Schatten q-norms for q ∈ (0, 1] and q < 0. The results are extensions of the Minkowski determinantal inequality. A few estimates for block-matrices are derived. For instance, let f : [0, ∞) → [0, ∞) be concave and p ∈(1, ∞). If fp(t) is superadditive, then [Formula: see text] for all positive m × m matrix A = [aij]. Furthermore, for the normalized trace τ, we consider functions φ(t) and f(t) for which the functional A ↦ φ ◦ τ ◦ f(A) is convex or concave, and obtain a simple analytic criterion.
L2-RHO FORM FOR NORMAL COVERINGS OF FIBER BUNDLES
Authors: AZZALI SARA
Published: March 2011

We define the secondary invariants L2-eta and -rho forms for families of generalized Dirac operators on normal coverings of fiber bundles. On the covering family we assume transversally smooth spectral projections and Novikov–Shubin invariants bigger than 3( dim B + 1) to treat the large time asymptotic for the heat operator. In the case of a bundle of spin manifolds, we study the L2-rho class in relation to the space [Formula: see text] of positive scalar curvature vertical metrics.
STRUCTURE RESULTS FOR NORMALIZERS OF II1 FACTORS
Authors: CAMERON JAN M.
Published: March 2011

For an inclusion N ⊆ M of II1 factors, we study the group of normalizers [Formula: see text] and the von Neumann algebra it generates. We first show that [Formula: see text] imposes a certain "discrete" structure on the generated von Neumann algebra. By analyzing the bimodule structure of certain subalgebras of [Formula: see text], this leads to a "Galois-type" theorem for normalizers, in which we find a description of the subalgebras of [Formula: see text] in terms of a unique countable subgroup of [Formula: see text]. Implications for inclusions B ⊆ M arising from the crossed product, group von Neumann algebra, and tensor product constructions will also be addressed. Our work leads to a construction of new examples of norming subalgebras in finite von Neumann algebras: If N ⊆ M is a regular inclusion of II1 factors, then N norms M.
TENSOR FUNCTORS ON A CERTAIN CATEGORY CONSTRUCTED FROM SPHERICAL CATEGORIES
Authors: ASAEDA MARTA
Published: March 2011

We construct functors from a certain algebraic category [Formula: see text], defined by Hopf algebra generators and relations, to the category of vector spaces, based on spherical categories. The category [Formula: see text] is proposed by Habiro to be isomorphic to the cobordism category of once-punctured surfaces. If the proposal is proved valid, the result of this paper would imply a construction of a TQFT functor based on a spherical category.
ARC NUMBERS FROM GAUSS DIAGRAMS
Authors: HAGGE TOBIAS
Published: March 2011

We characterize planar diagrams which may be divided into n arc embeddings in terms of their chord diagrams, generalizing a result of Taniyama for the case n = 2. Two algorithms are provided, one which finds a minimal arc embedding (in quadradic time in the number of crossings), and one which constructs a minimal subdiagram having the same arc number as D.
CHAIN HOMOTOPY MAPS FOR KHOVANOV HOMOLOGY
Authors: ITO NOBORU
Published: March 2011

Explicit chain homotopy maps and chain maps for the Reidemeister moves of Khovanov homology are often useful for several proofs of the isotopy invariance of Khovanov homology. However, such maps are missing except for the first Reidemeister moves given by Viro. In this paper, such chain homotopy maps and chain maps are obtained explicitly for the second and third Reidemeister moves (Sec. 2). Some applications are given to show the usefulness of these maps (Sec. 3).
A CATEGORIFICATION FOR THE PENROSE POLYNOMIAL
Authors: LUSE KERRY , RONG YONGWU
Published: March 2011

Given a graph, we construct homology groups whose Euler characteristic is the Penrose polynomial of the graph, evaluated at an integer. This work is motivated by Khovanov's work on the categorification of the Jones polynomial for knots, and the subsequent categorifications of the chromatic and Tutte polynomials for graphs.
THE SECOND QUANDLE HOMOLOGY OF THE TAKASAKI QUANDLE OF AN ODD ABELIAN GROUP IS AN EXTERIOR SQUARE OF THE GROUP
Authors: NIEBRZYDOWSKI MACIEJ , PRZYTYCKI JÓZEF H.
Published: March 2011

We prove that if G is an abelian group of odd order then there is an isomorphism from the second quandle homology [Formula: see text] to G ∧ G, where ∧ is the exterior product. In particular, for [Formula: see text], k odd, we have [Formula: see text]. Nontrivial [Formula: see text] allows us to use 2-cocycles to construct new quandles from T(G), and to construct link invariants. Computation of [Formula: see text] is also the first, fundamental step in the direction of computing homology of Takasaki quandles in general.
THE QUANTUM WORLD AND QUANTUM COMPUTING: FUNDAMENTAL ISSUES
Authors: PARKE WILLIAM C. , ESKANDARIAN ALI
Published: March 2011

Some of the fundamental issues in quantum theory related to quantum computing are reviewed and discussed. Particularly emphasized is the need to be diligent in what quantum theory predicts, and what it does not. The non-intuitive features of quantum theory, that are often associated with aspects of non-locality and that also arise in quantum computing and quantum information transfer, are described. Some discussion of topological quantum computing using space-time strings is presented, as well as general notions about quantum computing.
CLOSING THE LANGUAGE GAP FOR DEAF AND HARD OF HEARING CHILDREN
Authors: MORDESON JOHN N. , BURTON LISA R. , OLSON LYNN , FONG NELSON C. , LANUM NICOLE , ROSSI KAREN K.
Published: March 2011

We use techniques from fuzzy mathematics to develop metrics for measuring how well deaf and hard of hearing preschool students of Omaha Hearing School are closing the gap with respect to language growth.
COMPUTATION OF THE KÖTHE-TOEPLITZ DUAL OF SOME SETS OF SEQUENCES OF FUZZY NUMBERS
Authors: DUTTA HEMEN , REDDY B. SURENDER
Published: March 2011

The main aim of the present paper is to compute the α–dual (or Köthe-Toeplitz dual) for some sets of sequences of fuzzy numbers defined using an Orlicz function. We also compute the α–dual of some sets of difference sequences of fuzzy numbers.
DISTRIBUTED INTELLIGENCE IN MANUFACTURING INFORMATION SYSTEMS
Authors: RUSSELL DAVID W.
Published: March 2011

This paper describes an information system that was architected to enable front end distributed intelligence in a real manufacturing environment. By distributing intelligence to the most robust components of the system, data can be preserved at the cost of very real-time information. In order for the system as a whole to function this way, each software component was fitted with watchdog agent and granted system level access to the operating system so that it could detect and repair itself and other tasks in the event of a failure. During the repair process, the appropriate data collection processes were granted a level of autonomy that preserved data integrity. The paper is quite practical and designed as a case study rather than a theoretical research paper, although the techniques and principles applied are the result of much study.
A NOVEL APPROACH TO IMAGE THRESHOLDING BASED ON 2D HOMOGENEITY HISTOGRAM AND MAXIMUM FUZZY ENTROPY
Authors: CHENG H. D. , GUO YANHUI , ZHANG YINGTAO
Published: March 2011

Image thresholding is an important topic for image processing, pattern recognition and computer vision. Fuzzy set theory has been successfully applied to many areas, and it is generally believed that image processing bears some fuzziness in nature. In this paper, we employ the newly proposed 2D homogeneity histogram (homogram) and the maximum fuzzy entropy principle to perform thresholding. We have conducted experiments on a variety of images. The experimental results demonstrate that the proposed approach can select the thresholds automatically and effectively. Especially, it not only can process "clean" images, but also can process images with different kinds of noises and images with multiple kinds of noise well without knowing the type of the noise, which is the most difficult task for image thresholding. It will be useful for applications in computer vision and image processing.
A NOVEL IMAGE SEGMENTATION APPROACH BASED ON NEUTROSOPHIC SET AND IMPROVED FUZZY C-MEANS ALGORITHM
Authors: CHENG H. D. , GUO YANHUI , ZHANG YINGTAO
Published: March 2011

Image segmentation is an important component in image processing, pattern recognition and computer vision. Many segmentation algorithms have been proposed. However, segmentation methods for both noisy and noise-free images have not been studied in much detail.

Neutrosophic set (NS), a part of neutrosophy theory, studies the origin, nature, and scope of neutralities, as well as their interaction with different ideational spectra. However, neutrosophic set needs to be specified and clarified from a technical point of view for a given application or field to demonstrate its usefulness.

In this paper, we apply neutrosophic set and define some operations. Neutrosphic set is integrated with an improved fuzzy c-means method and employed for image segmentation. A new operation, α-mean operation, is proposed to reduce the set indeterminacy. An improved fuzzy c-means (IFCM) is proposed based on neutrosophic set. The computation of membership and the convergence criterion of clustering are redefined accordingly. We have conducted experiments on a variety of images. The experimental results demonstrate that the proposed approach can segment images accurately and effectively. Especially, it can segment the clean images and the images having different gray levels and complex objects, which is the most difficult task for image segmentation.
LINGUISTIC INVENTORY PROBLEMS
Authors: HSIEH CHIH HSUN
Published: March 2011

The work presented in this paper has been motivated primarily by Zadeh's idea of linguistic variables intended to provide rigorous mathematical modeling of natural language and CWW, Computing With Words. This paper reports some modeling of the linguistic inventory problems where CWW have been implemented: linguistic production inventory, linguistic inventory models under linguistic demand and linguistic lead time, linguistic production inventory models based on the preference of a decision maker, and linguistic inventory model for fuzzy reorder point and fuzzy safety stock. Only studies that focus on CWW, two linguistic inventory models and two linguistic backorder inventory models, which each model is combined by the heuristic fuzzy total inventory cost based on the preference of a decision maker, are proposed in this paper. The heuristic fuzzy total inventory cost of each model is modeled by linguistic values in natural language, fuzzy numbers, and crisp real numbers. It is also computed and defuzzified by using some fuzzy arithmetical operations by Function Principle and Graded k-preference integration representation method, respectively. In addition, Extension of the LaGrangean method is used for solving inequality constrain problem in the proposed linguistic inventory environments. Furthermore, we find that our heuristic optimal solutions of the new introduced modeling the linguistic inventory problems can also be specified to meet the classical inventory models, when all linguistic variables are crisp real numbers, such as the previous proposed linguistic inventory models.
Relationship between Crosscutting Concerns and Defects
Authors: Kumar Pankaj , Dutta Kamlesh
Published: March 2011

NOTE FROM ACM: It has been determined that this paper plagiarized earlier works. Therefore ACM has shut off access to this paper.

The paper by Pankaj Kumar and Kamlesh Dutta plagiarizes the following work: Marc Eaddy, Vibhav Garg, Alfred Aho, Nachiappan Nagappan, Kaitlin Duck Sherwood, "On the Relationship between Crosscutting Concerns and Defects: An Empirical Investigation"
found here
, as well as the article: Eaddy, M.; Zimmermann, T.; Sherwood, K.D.; Garg, V.; Murphy, G.C.; Nagappan, N.; Aho, A.V.; , "Do Crosscutting Concerns Cause Defects?," Software Engineering, IEEE Transactions on , vol.34, no.4, pp.497-515, July-Aug. 2008 .
http://dx.doi.org/10.1109/TSE.2008.36
.

For further information, contact the
ACM Director of Publications.
Interventricular heterogeneity in rat heart responses to hypoxia: the tuning of glucose metabolism, ion gradients, and function
Authors: Komniski Milena Segato , Yakushev Sergej , Bogdanov Nikolai , Gassmann Max , Bogdanova Anna
Published: March 2011

The matching of energy supply and demand under hypoxic conditions is critical for sustaining myocardial function. Numerous reports indicate that basal energy requirements and ion handling may differ between the ventricles. We hypothesized that ventricular response to hypoxia shows interventricular differences caused by the heterogeneity in glucose metabolism and expression and activity of ion transporters. Thus we assessed glucose utilization rate, ATP, sodium and potassium concentrations, Na, K-ATPase activity, and tissue reduced:oxidized glutathione (GSH/GSSG) content in the right and left ventricles before and after the exposure of either the whole animals or isolated blood-perfused hearts to hypoxia. The hypoxia-induced boost in glucose utilization was more pronounced in the left ventricle compared with the right one. ATP levels in the right ventricle of hypoxic heart were lower than those in the left ventricle. Left ventricular sodium content was higher, and hydrolytic Na, K-ATPase activity was reduced compared with the right ventricle. Administration of the Na, K-ATPase blocker ouabain caused rapid increase in the right ventricular Na+and elimination of the interventricular Na+gradients. Exposure of the hearts to hypoxia made the interventricular heterogeneity in the Na+distribution even more pronounced. Furthermore, systemic hypoxia caused oxidative stress that was more pronounced in the right ventricle as revealed by GSH/GSSG ratios. On the basis of these findings, we suggest that the right ventricle is more prone to hypoxic damage, as it is less efficient in recruiting glucose as an alternative fuel and is particularly dependent on the efficient Na, K-ATPase function.
Porcine coronary collateral formation in the absence of a pressure gradient remote of the ischemic border zone
Authors: van den Wijngaard Jeroen P. H. M. , Schulten Henny , van Horssen Pepijn , ter Wee Rene D. , Siebes Maria , Post Mark J. , Spaan Jos A. E.
Published: March 2011

In the current paradigm on coronary collateral development, it is assumed that these vessels develop consequentially from increased fluid shear stress (FSS) through preexisting collateral arteries. The increased FSS follows from an increase in pressure gradient between the region at risk and well-perfused surroundings. The objective of this study was to test the hypothesis that, in the heart, collateral connections can form in the absence of an increased FFS and consequentially at any depth and region within the ventricular wall. In Yorkshire pigs, gradual left circumflex coronary artery occlusion was obtained over 6 wk by an ameroid constrictor, whereas the control group underwent a sham operation. Hearts were harvested and subsequently processed in an imaging cryomicrotome, resulting in 40-μm voxel resolution three-dimensional reconstructions of the intramural vascular vessels. Dedicated software segmented the intramural vessels and all continuous vascular pathways containing a collateral connection. In the ameroid group, 192 collaterals, 22–1,049 μm in diameter, were detected with 62% within the subendocardium. Sixty percent of collaterals bridged from the left anterior descending artery to left circumflex coronary artery. A novel result is that 25% ( n = 48) of smaller-radius collaterals ( P = 0.047) connected with both origin and terminus in the nontarget area where perfusion was assumed uncompromised. In the porcine heart, collateral vessels develop not only in ischemic border zones with increased FSS but also away from such border zones where increased FSS is unlikely. The majority of collaterals were located at the subendocardium, corresponding to the region with highest prevalence for ischemia.
Mitigation of the progression of heart failure with sildenafil involves inhibition of RhoA/Rho-kinase pathway
Authors: Chau Vinh Q. , Salloum Fadi N. , Hoke Nicholas N. , Abbate Antonio , Kukreja Rakesh C.
Published: March 2011

Chronic inhibition of phosphodiesterase-5 with sildenafil immediately after permanent occlusion of the left anterior descending coronary artery was shown to limit ischemic heart failure (HF) in mice. To mimic a more clinical scenario, we postulated that treatment with sildenafil beginning at 3 days post-myocardial infarction (MI) would also reduce HF progression through the inhibition of the RhoA/Rho-kinase pathway. Adult male ICR mice with fractional shortening < 25% at day 3 following permanent left anterior descending coronary artery ligation were continuously treated with either saline (volume matched, ip, 2 times/day) or sildenafil (21 mg/kg, ip, 2 times/day) for 25 days. Echocardiography showed fractional shortening preservation and less left ventricular end-diastolic dilatation with sildenafil treatment compared with saline treatment at 7 and 28 days post-MI ( P < 0.05). Both fibrosis and apoptosis, determined by Masson's trichrome and terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL), respectively, were attenuated in the sildenafil-treated mice ( P < 0.05 vs. saline). Western blot analysis showed enchanced Bcl-2-to-Bax ratio with sildenafil treatment ( P < 0.05 vs. saline). Activity assay showed sildenafil-mediated PKG activation 1 day after treatment ( P < 0.05 vs. sham and saline). PKG activation was associated with sildenafil-mediated inhibition of Rho kinase ( P < 0.05) compared with saline treatment, whereas PKG inhibition with KT-5823 abolished this inhibitory effect of sildenafil. In conclusion, for the first time, our findings show that chronic sildenafil treatment, initiated at 3 days post-MI, attenuates left ventricular dysfunction independent of its infarct-sparing effect, and this cardioprotection involves the inhibition of the RhoA/Rho-kinase pathway. Sildenafil may be a promising therapeutic tool for advanced HF in patients.
Arrhythmogenic substrate in hearts of rats with monocrotaline-induced pulmonary hypertension and right ventricular hypertrophy
Authors: Benoist David , Stones Rachel , Drinkhill Mark , Bernus Olivier , White Ed
Published: March 2011

Mechanisms associated with right ventricular (RV) hypertension and arrhythmias are less understood than those in the left ventricle (LV). The aim of our study was to investigate whether and by what mechanisms a proarrhythmic substrate exists in a rat model of RV hypertension and hypertrophy. Rats were injected with monocrotaline (MCT; 60 mg/kg) to induce pulmonary artery hypertension or with saline (CON). Myocardial levels of mRNA for genes expressing ion channels were measured by real-time RT-PCR. Monophasic action potential duration (MAPD) was recorded in isolated Langendorff-perfused hearts. MAPD restitution was measured, and arrhythmias were induced by burst stimulation. Twenty-two to twenty-six days after treatment, MCT animals had RV hypertension, hypertrophy, and decreased ejection fractions compared with CON. A greater proportion of MCT hearts developed sustained ventricular tachycardias/fibrillation (0.83 MCT vs. 0.14 CON). MAPD was prolonged in RV and less so in the LV of MCT hearts. There were decreased levels of mRNA for K+ channels. Restitution curves of MCT RV were steeper than CON RV or either LV. Dispersion of MAPD was greater in MCT hearts and was dependent on stimulation frequency. Computer simulations based on ion channel gene expression closely predicted experimental changes in MAPD and restitution. We have identified a proarrhythmic substrate in the hearts of MCT-treated rats. We conclude that steeper RV electrical restitution and rate-dependant RV-LV action potential duration dispersion may be contributing mechanisms and be implicated in the generation of arrhythmias associated with in RV hypertension and hypertrophy.
Cholesterol diet leads to attenuation of ischemic preconditioning-induced cardiac protection: the role of connexin 43
Authors: Görbe Anikó , Varga Zoltán V. , Kupai Krisztina , Bencsik Péter , Kocsis Gabriella F. , Csont Tamás , Boengler Kerstin , Schulz Rainer , Ferdinandy Péter
Published: March 2011

Cardioprotection by ischemic preconditioning (IP) was abolished in connexin 43 (Cx43)-deficient mice due to loss of Cx43 located in mitochondria rather than at the sarcolemma. IP is lost in hyperlipidemic rat hearts as well. Since changes in mitochondrial Cx43 in hyperlipidemia have not yet been analyzed, we determined total and mitochondrial Cx43 levels in male Wistar rats fed a laboratory chow enriched with 2% cholesterol or normal chow for 12 wk. Hearts were isolated and perfused according to Langendorff. After a 10-min perfusion, myocardial tissue cholesterol, superoxide, and nitrotyrosine contents were measured and Cx43 content in whole heart homogenate and a mitochondrial fraction determined. In the cholesterol-fed group, tissue cholesterol and superoxide formation was increased ( P < 0.05), while total Cx43 content remained unchanged. Mitochondrial total and dephosphorylated Cx43 content decreased. Hearts were subjected to an IP protocol (3 × 5 min ischemia-reperfusion) or time-matched aerobic perfusion followed by 30-min global ischemia and 5-min reperfusion. IP reduced infarct size in normal but not in cholesterol-fed rats. At 5-min reperfusion following 30-min global ischemia, the total and dephosphorylated mitochondrial Cx43 content was increased, which was abolished by IP in both normal and high-cholesterol diet. In conclusion, loss of cardioprotection by IP in hyperlipidemia is associated with a redistribution of both sarcolemmal and mitochondrial Cx43.
Convergence of Iterative Sequences for Common Zero Points of a Family of "Equation missing" -Accretive Mappings in Banach Spaces
Authors: Qing Yuan , Cho SunYoung , Qin Xiaolong
Published: March 2011

We introduce implicit and explicit viscosity iterative algorithms for a finite family of "Equation missing"-accretive operators. Strong convergence theorems of the iterative algorithms are established in a reflexive Banach space which has a weakly continuous duality map.
An Initial Investigation of Adjoint‐Based Unstructured Grid Adaptation for Vortical Flow Simulations
Authors: Li Li
Published: March 2011

A computational fluid dynamics (CFDs) method
utilizing unstructured grid technology has been
employed to compute vortical flow around a 65°
delta wing with sharp leading edge, which is specially known as the geometry of the second international vortex flow experiment (VFE‐2). In
VFE‐2, 65° delta wings with different leading
edges had been broadly investigated by experiments, which resulted in a special database for
CFDs codes validation. The emphasis of this
paper is to investigate the effectiveness of an
adjoint‐base grid adaptation method for unstructured grid in capturing concentrated vortices generated at sharp edges or flow separation lines of
lifting surfaces flying at high angles of attack.
Earlier experiences in vortical flow simulations
had indicated that the vortex behavior is highly
dependent on the local grid resolution both on
body surface and space. The adjoint‐based adaptation method used here is hoped to save grid
points with a reasonable grid resolution for vortical flow simulations. The basic idea is to construct a new adaptive sensor in a grid adaptation process with the intent to tell where the elements should be smaller or larger by introducing an adjoint formulation to relate the estimated
functional error to local residual errors of both
the primal and adjoint solutions.
Pancreatic Serous Cystadenoma with Compression of the Main Pancreatic Duct: An Unusual Entity
Authors: Truant Stéphanie , Izgarevic D. , Maunoury Vincent , Buob David , Bulois Philippe , Ernst Olivier , Huet Guillemette , Zerbib Philippe , Pruvot François-René
Published: March 2011

Serous cystadenoma is a common benign neoplasm that can be managed without surgery in asymptomatic patients provided that the diagnosis is certain. We describe a patient, whose pancreatic cyst exhibited a radiological appearance distinct from that of typical serous cystadenoma, resulting in diagnostic difficulties. CT and MRI showed a 10 cm-polycystic tumor with upstream dilatation of the main pancreatic duct (MPD), suggestive of intraductal papillary mucinous tumor (IPMT). Ultrasonographic aspect and EUS-guided fine-needle aspiration gave arguments for serous cystadenoma. ERCP showed a communication between cysts and the dilated MPD, compatible with IPMT. The patient underwent left pancreatectomy with splenectomy. Pathological examination concluded in a serous cystadenoma, with only a ductal obstruction causing proximal dilatation.
Biochanin A, a Phytoestrogenic Isoflavone with Selective Inhibition of Phosphodiesterase 4, Suppresses Ovalbumin‐Induced Airway Hyperresponsiveness
Authors: Ko Wun-Chang , Lin Ling-Hung , Shen Hsin-Yi , Lai Chi-Yin , Chen Chien-Ming , Shih Chung-Hung
Published: March 2011

The present study investigated the potential of biochanin A, a phytoestrogenic
isoflavone of red clover (Triflolium pratense), for use in treating asthma or chronic
obstructive pulmonary disease (COPD). Biochanin A (100 μmol/kg, orally (p.o.))
significantly attenuated airway resistance (RL), enhanced pause (Penh), and increased lung dynamic compliance (Cdyn) values induced by methacholine (MCh) in sensitized and challenged mice. It also significantly suppressed an increase in the number of total inflammatory cells, neutrophils, and eosinophils, and levels of cytokines,
including interleukin (IL)‐2, IL‐4, IL‐5, and tumor necrosis factor (TNF)‐α in
bronchoalveolar lavage fluid (BALF) of the mice. However, it did not influence
interferon (IFN)‐γ levels. Biochanin A (100 μmol/kg, p.o.) also significantly
suppressed the total and ovalbumin (OVA)‐specific immunoglobulin E (IgE) levels in
the serum and BALF, and enhanced the total IgG2a level in the serum of these mice.
The PDE4H/PDE4L value of biochanin A was calculated as >35. Biochanin A did not influence xylazine/ketamine‐induced anesthesia. Biochanin A (10~30 μM) significantly reduced cumulative OVA (10~100 μg/mL)‐induced contractions in the isolated guinea pig trachealis, suggesting that it inhibits degranulation of mast cells.
In conclusion, red clover containing biochanin A has the potential for treating allergic asthma and COPD.
Latitude-Time Total Electron Content Anomalies as Precursors to Japan's Large Earthquakes Associated with Principal Component Analysis
Authors: Lin Jyh-Woei
Published: March 2011

The goal of this study is to determine whether principal component analysis (PCA) can be used to process latitude-time ionospheric TEC data on a monthly basis to identify earthquake associated TEC anomalies. PCA is applied to latitude-time (mean-of-a-month) ionospheric total electron content (TEC) records collected from the Japan GEONET network to detect TEC anomalies associated with 18 earthquakes in Japan () from 2000 to 2005. According to the results, PCA was able to discriminate clear TEC anomalies in the months when all 18 earthquakes occurred. After reviewing months when no earthquakes occurred but geomagnetic storm activity was present, it is possible that the maximal principal eigenvalues PCA returned for these 18 earthquakes indicate earthquake associated TEC anomalies. Previously PCA has been used to discriminate earthquake-associated TEC anomalies recognized by other researchers, who found that statistical association between large earthquakes and TEC anomalies could be established in the 5 days before earthquake nucleation; however, since PCA uses the characteristics of principal eigenvalues to determine earthquake related TEC anomalies, it is possible to show that such anomalies existed earlier than this 5-day statistical window.
Strong Convergence Theorems for an Infinite Family of Equilibrium Problems and Fixed Point Problems for an Infinite Family of Asymptotically Strict Pseudocontractions
Authors: Wang Shenghua , Kang ShinMin , Kwun YoungChel
Published: March 2011

We prove a strong convergence theorem for an infinite family of asymptotically strict pseudo-contractions and an infinite family of equilibrium problems in a Hilbert space. Our proof is simple and different from those of others, and the main results extend and improve those of many others.
Recent Efforts for Credible CFD Simulations in China
Authors: Li Li , Wen Bai , Yihua Liang
Published: March 2011

In this paper some recent efforts for credible computational fluid dynamics (CFD) simulations in China are reviewed. The most important effort is that, following similar activities in the West such as ECARP and AIAA Drag Prediction Workshops, a series of workshops on credible CFD simulations had been initiated. These workshops were with ambitions to assess the status of CFD in China. Another major effort is an ongoing project to establish a software platform for studying the credibility of CFD solvers and performing credible CFD simulations. The platform, named WiseCFD, was designed to implement a seamless CFD process and to circumvent tedious repeating manual operations. It had also been a powerful job manager for CFD with capabilities to support plug and play (PnP) solver integration as well as distributed or parallel computations. Some future work on WiseCFD was proposed, and also envisioned was how WiseCFD and the European QNET‐CFD Knowledge Base can benefit mutually.
A Three‐Species Food Chain System with Two Types of Functional Responses
Authors: Do Younghae , Baek Hunki , Lim Yongdo , Lim Dongkyu
Published: March 2011

In recent decades, many researchers have investigated the ecological models with three and more species to understand complex dynamical behaviors of ecological systems in nature. However,
when they studied the models with three species, they have just considered the functional responses between prey and mid‐predator and between mid‐predator and top predator as the same type. However, in the paper, in order to describe more realistic ecological world, a three‐species food chain system with two types of functional response, Holling type and Beddington‐DeAngelis type, is considered. It is shown that this system is dissipative. Also, the local and global stability
of equilibrium points of the system is established. In addition, conditions for the persistence of
the system are found according to the existence of limit cycles. Some numerical examples are
given to substantiate our theoretical results. Moreover, we provide numerical evidence of the existence
of chaotic phenomena by illustrating bifurcation diagrams of system and by calculating
the largest Lyapunov exponent.
Mites (Acari) Associated with the Desert Seed Harvester Ant,Messor pergandei(Mayr)
Authors: Uppstrom Kaitlin A. , Klompen Hans
Published: March 2011

Mites (Acari) associated with the seed harvester antMessor pergandeiwere investigated in the Sonoran desert of Arizona. At least seven representatives of the mite generaArmacarus, Lemanniella, Petalomium, Forcellinia, Histiostoma, Unguidispus, andCosmoglyphusare phoretically associated withM. pergandei. Most of these morphospecies show preference for specific phoretic attachment sites and primarily use female alates rather than male alates for dispersal. Five mite morphospecies were found in low numbers inhabiting the chaff piles: Tydeidae sp.,Procaeculussp., Anystidae sp.,Bakerdaniasp., and Tetranychidae sp. The phoreticPetalomiumsp. was observed consuming fungus growing on a dead queen, but the roles of the other mite species remain mostly unresolved.