bluuebunny/crossref_metadata_2025 huggingface dataset:
Value of and Interaction between Production Postponement and Information Sharing Strategies for Supply Chain Firms
Authors: Cavusoglu Hasan , Cavusoglu Huseyin , Raghunathan Srinivasan
Published: December 2011

We analyze the value of and interaction between production postponement and information sharing, which are two distinct strategies to reduce manufacturers’ uncertainty about demand. In both single‐level and two‐level supply chains, from the manufacturer's perspective, while information sharing is always valuable, production postponement can sometimes be detrimental. Furthermore, the value of production postponement is not merely driven by savings in inventory holding cost as postponement enables the manufacturer to avoid both excess and shortfall in production. We find that production postponement and information sharing strategies may substitute, complement, or conflict with each other, depending on the extent of the increase in the unit production cost when production is postponed. In a two‐level supply chain, from the retailer's perspective, information sharing and production postponement can be beneficial or detrimental. When information sharing is beneficial to the retailer, the retailer always shares her demand information with the manufacturer voluntarily. In addition, this voluntary information sharing is truthful because inflated or deflated demand information hurts the retailer through a higher wholesale price or a stock‐out. However, the retailer never shares her demand information voluntarily if the manufacturer has already adopted production postponement because production postponement and information sharing strategies always conflict with each other. Even when the retailer does not benefit from information sharing, we show that the manufacturer can always design an incentive mechanism to induce the retailer to share the demand information, irrespective of whether the manufacturer has already implemented production postponement or not. The above findings underscore the need for a careful assessment of demand uncertainty‐reduction strategies before the supply chain players embark upon them.
Grocery Perishables Management
Authors: Li Yanzhi , Cheang Brenda , Lim Andrew
Published: December 2011

In this article, we study the joint pricing and inventory control problem for perishables when a retailer does not sell new and old inventory at the same time. At the beginning of a period, the retailer makes replenishment and pricing decisions, and at the end of a period, the retailer decides whether to dispose of ending inventory or carry it forward to the next period. The objective of the retailer is to maximize the long‐run average profit. Assuming zero lead time, we propose an efficient solution approach to the problem, which is also generalized to solve three extensions to the basic model. A feature of the present study is that we consider explicitly the influence of perishability on the demand. Among the insights gathered from the numerical analysis, we find that dynamic pricing aids extending shelf life and when disposal incurs a lower cost, or even a positive salvage value, the retailer is induced to dispose earlier since the benefit of selling new inventory offsets the loss due to disposal. We also observe that the faster the perceived rate of deterioration, the lower the threshold of the ending inventory for disposal. Perhaps a bit counter‐intuitive, maximizing profits does not mean eliminating disposals or expirations.
Ordering, Pricing, and Lead‐Time Quotation Under Lead‐Time and Demand Uncertainty
Authors: Wu Zhengping , Kazaz Burak , Webster Scott , Yang Kum‐Khiong
Published: December 2011

In this article, we study the newsvendor problem with endogenous setting of price and quoted lead‐time. This problem can be observed in situations where a firm orders semi‐finished product prior to the selling season and customizes the product in response to customer orders during the selling season. The total demand during the selling season and the lead‐time required for customization are uncertain. The demand for the product depends not only on the selling price but also on the quoted lead‐time. To set the quoted lead‐time, the firm has to carefully balance the benefit of increasing demand as the quoted lead‐time is reduced against the cost of increased tardiness. Our model enables the firm to determine the optimal selling price, quoted lead‐time, and order quantity simultaneously, and provides a new set of insights to managers.
How Does Product Recovery Affect Quality Choice?
Authors: Atasu Atalay , Souza Gilvan C.
Published: December 2011

We study the impact of product recovery on a firm's product quality choice, where quality is defined as an observable performance measure that increases a consumer's valuation for the product. We consider three general forms of product recovery: (i) when product recovery reuses (after reprocessing) quality inducing components or material (e.g., remanufacturing), (ii) when product recovery does not reuse quality inducing components or material but it is overall profitable (e.g., cell phone recycling), and (iii) when product recovery is costly (but mandated by legislation, e.g., recycling of small appliances in the European Union). Using a stylized economic model, we show that the form of product recovery, recovery cost structure, and the presence of product take‐back legislation play an important role in quality choice. Generally speaking, product recovery increases the firm's quality choice, except for some instances of recovery form (ii). In addition, we find that product take‐back legislation can lead to higher quality choice as opposed to voluntary take‐back. We further demonstrate that both the firm and the consumers benefit from recovery form (ii), while both are worse off with recovery form (iii). However, environmental implications of the three recovery modes differ from their impact on consumer surplus and firm profit. While recovery forms (i) and (iii) reduce consumption and increase environmental benefits, the same is not true with recovery form (ii), which can increase consumption, potentially resulting in higher environmental impact.
What do NHS staff learn from training on the Mental Capacity Act (2005)?
Authors: Willner Paul , Bridle Jennifer , Price Vaughn , Dymond Simon , Lewis Glenda
Published: December 2011

Purpose. Many studies have reported that professionals have a limited understanding of mental capacity issues. Implementation (in England and Wales) of the Mental Capacity Act (MCA) (2005) presents a challenge to services. The aim of this study was to evaluate the extent to which National Health Service (NHS) staff benefited from attending MCA training courses.

Methods. Participants were assessed before and after MCA training using a structured interview, which included three scenarios describing mental capacity dilemmas, four vignettes addressing the role of the Independent Mental Capacity Advocate (IMCA), and 16 true–false items.

Results. Interview performance improved post‐training, but this could be largely ascribed to an increased awareness of mental capacity issues, with minimal improvements in the knowledge that would be needed to undertake the assessments. Nine areas were identified where there remained significant gaps in participants’ knowledge post‐training. Participants with experience of dealing with mental capacity issues performed better than those without.

Conclusions. The results suggest that methods other than formal training events may be needed to prepare health staff to implement new legislation.
Bovine Cortical Bone Stiffness and Local Strain are Affected by Mineralization and Morphology
Authors: Budyn É. , Jonvaux J. , Funfschilling C. , Hoc T.
Published: December 2011

A multiscale analysis of the mechanical behavior of bovine Haversian cortical bone is presented in the frame-work of linear elasticity. Cortical bone displays a complex microstructure that includes four phases: Haversian canals, osteons, cement lines, and interstitial bone. Based on close experimental observations, a Monte Carlo algorithm is implemented to build the natural bone composite microstructure. To represent the hierarchical nature of bone, the algorithm incorporates macroscopic morphological components, such as its porosity and osteonal volume fraction, as well as microscopic parameters, such as the characterized distributions of the osteons diameters. Bone local mechanical properties are measured by nanoindentation and microextensometry. The three-dimensional microstructures are discretized by a finite element method in order to evaluate the representative volume element of bovine cortical bone. The numerical model calculates the macroscopic bulk and material Young’s moduli and describes the local stress and strain. How geometrical or mechanical factors affect bone failure is investigated through a comparison of the macroscopic anisotropy and local strain to experimental data.
Analytical Treatment of the Free Vibration of Single-Walled Carbon Nanotubes Based on the Nonlocal Flugge Shell Theory
Authors: Ansari R. , Rouhi H.
Published: December 2011

In the current work, the vibration characteristics of single-walled carbon nanotubes (SWCNTs) under different boundary conditions are investigated. A nonlocal elastic shell model is utilized, which accounts for the small scale effects and encompasses its classical continuum counterpart as a particular case. The variational form of the Flugge type equations is constructed to which the analytical Rayleigh–Ritz method is applied. Comprehensive results are attained for the resonant frequencies of vibrating SWCNTs. The significance of the small size effects on the resonant frequencies of SWCNTs is shown to be dependent on the geometric parameters of nanotubes. The effectiveness of the present analytical solution is assessed by the molecular dynamics simulations as a benchmark of good accuracy. It is found that, in contrast to the chirality, the boundary conditions have a significant effect on the appropriate values of nonlocal parameter.
The Use of Potting Materials for Electronic-Packaging Survivability in Smart Munitions
Authors: Chao N. H. , Cordes J. A. , Carlucci D. , DeAngelis M. E. , Lee Jyeching
Published: December 2011

Potted electronics are becoming more common in precision-guided artillery due to demands for increased structural-robustness. In field artillery applications, the potted electronics are inactive for most of their lifetime. Projectiles may be stored in a bunker without environmental (temperature and humidity) controls for up to 20 years. In contrast, the electronics for most commercial applications tend to be active for most of their lifetime and the operating environment is more predictable. This difference makes the thermal management task for the artillery application challenging. The ability to accurately analyze these designs requires the use of fully coupled thermal-stress transient-analysis with accurate material properties over the full temperature range. To highlight the thermal-stress transient effects, the potted configuration of a typical electronics assembly is analyzed. The thermal analysis indicates that significant stresses can develop in critical locations as a result of temperature cycles. The structural dynamic responses of unpotted and potted assemblies, subjected to gun-launch environments, are also compared. The results indicate that for the potted design, the dynamic response of the processor board is attenuated by the potting material.
Optimizing Perovskites for the Water-Splitting Reaction
Authors: Vojvodic Aleksandra , Nørskov Jens K.
Published: December 2011

The electron occupation of orbitals in transition metal oxides guided the identification of an efficient oxygen evolution catalyst based on Earth-abundant elements.
Science Meets Farming in Africa
Authors: Juma Calestous
Published: December 2011

The role of science, technology, and engineering in solving Africa's most challenging economic problems—from telecommunications to agriculture to infectious diseases—is no longer in question. However, some leading international organizations undermine the role of innovation in development. The time has come for the scientific community to advance a new generation of international organizations that expressly promote scientific cooperation—agencies that can help foster technological cooperation for Africa's economic transformation.
Emergence and Continuous Evolution of Genotype 1E Rubella Viruses in China
Authors: Zhu Zhen , Cui Aili , Wang Huanhuan , Zhang Yan , Liu Chunyu , Wang Changyin , Zhou Shujie , Chen Xia , Zhang Zhenying , Feng Daxin , Wang Yan , Chen Haiyun , Pan Zhengfan , Zeng Xiangjie , Zhou Jianhui , Wang Shuang , Chang Xin , Lei Yue , Tian Hong , Liu Yang , Zhou Shunde , Zhan Jun , Chen Hui , Gu Suyi , Tian Xiaoling , Liu Jianfeng , Chen Ying , Fu Hong , Yang Xiuhui , Zheng Huanying , Liu Leng , Zheng Lei , Gao Hui , He Jilan , Sun Li , Xu Wenbo
Published: December 2011

In China, rubella vaccination was introduced into the national immunization program in 2008, and a rubella epidemic occurred in the same year. In order to know whether changes in the genotypic distribution of rubella viruses have occurred in the postvaccination era, we investigate in detail the epidemiological profile of rubella in China and estimate the evolutionary rate, molecular clock phylogeny, and demographic history of the predominant rubella virus genotypes circulating in China using Bayesian Markov chain Monte Carlo phylodynamic analyses. 1E was found to be the predominant rubella virus genotype since its initial isolation in China in 2001, and no genotypic shift has occurred since then. The results suggest that the global 1E genotype may have diverged in 1995 and that it has evolved at a mutation rate of 1.65 × 10
−3
per site per year. The Chinese 1E rubella virus isolates were grouped into either cluster 1 or cluster 2, which likely originated in 1997 and 2006, respectively. Cluster 1 viruses were found in all provinces examined in this study and had a mutation rate of 1.90 × 10
−3
per site per year. The effective number of infections remained constant until 2007, and along with the introduction of rubella vaccine into the national immunization program, although the circulation of cluster 1 viruses has not been interrupted, some viral lineages have disappeared, and the epidemic started a decline that led to a decrease in the effective population size. Cluster 2 viruses were found only in Hainan Province, likely because of importation.
Rapid Identification of Mycobacteria and Drug-Resistant Mycobacterium tuberculosis by Use of a Single Multiplex PCR and DNA Sequencing
Authors: Pérez-Osorio Ailyn C. , Boyle David S. , Ingham Zachary K. , Ostash Alla , Gautom Romesh K. , Colombel Craig , Houze Yolanda , Leader Brandon T.
Published: December 2011

Tuberculosis (TB) remains a significant global health problem for which rapid diagnosis is critical to both treatment and control. This report describes a multiplex PCR method, the Mycobacterial IDentification and Drug Resistance Screen (MID-DRS) assay, which allows identification of members of theMycobacterium tuberculosiscomplex (MTBC) and the simultaneous amplification of targets for sequencing-based drug resistance screening of rifampin-resistant (rifampinr), isoniazidr, and pyrazinamiderTB. Additionally, the same multiplex reaction amplifies a specific 16S rRNA gene target for rapid identification ofM. aviumcomplex (MAC) and a region of the heat shock protein 65 gene (hsp65) for further DNA sequencing-based confirmation or identification of other mycobacterial species. Comparison of preliminary results generated with MID-DRS versus culture-based methods for a total of 188 bacterial isolates demonstrated MID-DRS sensitivity and specificity as 100% and 96.8% for MTBC identification; 100% and 98.3% for MAC identification; 97.4% and 98.7% for rifampinrTB identification; 60.6% and 100% for isoniazidrTB identification; and 75.0% and 98.1% for pyrazinamiderTB identification. The performance of the MID-DRS was also tested on acid-fast-bacterium (AFB)-positive clinical specimens, resulting in sensitivity and specificity of 100% and 78.6% for detection of MTBC and 100% and 97.8% for detection of MAC. In conclusion, use of the MID-DRS reduces the time necessary for initial identification and drug resistance screening of TB specimens to as little as 2 days. Since all targets needed for completing the assay are included in a single PCR amplification step, assay costs, preparation time, and risks due to user errors are also reduced.
Human Leptospira Isolates Circulating in Mayotte (Indian Ocean) Have Unique Serological and Molecular Features
Authors: Bourhy P. , Collet L. , Lernout T. , Zinini F. , Hartskeerl R. A. , van der Linden Hans , Thiberge J. M. , Diancourt L. , Brisse S. , Giry C. , Pettinelli F. , Picardeau M.
Published: December 2011

Leptospirosis is one of the most widespread zoonoses in the world. However, there is a lack of information on circulating
Leptospira
strains in remote parts of the world. We describe the serological and molecular features of leptospires isolated from 94 leptospirosis patients in Mayotte, a French department located in the Comoros archipelago, between 2007 and 2010. Multilocus sequence typing identified these isolates as
Leptospira interrogans
,
L. kirschneri
,
L. borgpetersenii
, and members of a previously undefined phylogenetic group. This group, consisting of 15 strains, could represent a novel species. Serological typing revealed that 70% of the isolates belonged to the serogroup complex Mini/Sejroe/Hebdomadis, followed by the serogroups Pyrogenes, Grippotyphosa, and Pomona. However, unambiguous typing at the serovar level was not possible for most of the strains because the isolate could belong to more than one serovar or because serovar and species did not match the original classification. Our results indicate that the serovar and genotype distribution in Mayotte differs from what is observed in other regions, thus suggesting a high degree of diversity of circulating isolates worldwide. These results are essential for the improvement of current diagnostic tools and provide a starting point for a better understanding of the epidemiology of leptospirosis in this area of endemicity.
Epidemiology and Risk Factors of Community Onset Infections Caused by Extended-Spectrum β-Lactamase-Producing Escherichia coli Strains
Authors: Kang Cheol-In , Wi Yu Mi , Lee Mi Young , Ko Kwan Soo , Chung Doo Ryeon , Peck Kyong Ran , Lee Nam Yong , Song Jae-Hoon
Published: December 2011

Limited clinical information is available regarding community onset infections caused by extended-spectrum β-lactamase (ESBL)-producing
Escherichia coli
. A case-control study was performed to evaluate the epidemiology and risk factors of these types of infections. A case patient was defined as a person whose clinical sample yielded ESBL-producing
E. coli
. For each case patient, one control was randomly chosen from a group of outpatients from whom non-ESBL-producing
E. coli
had been isolated and for whom a clinical sample had been sent to the same laboratory for culturing during the following week. Of 108 cases of ESBL-producing
E. coli
, 56 (51.9%) were classified as health care associated (HCA). Univariate analysis showed male gender, HCA infection, severe underlying illness, and a prior receipt of antibiotics to be associated with ESBL-producing
E. coli
. In the multivariate analysis, HCA infection (odds ratio [OR], 3.18; 95% confidence interval [CI], 1.67 to 6.06;
P
< 0.001) and previous use of antibiotics (OR, 4.88; 95% CI, 2.08 to 11.48;
P
< 0.001) were found to be significantly associated with the ESBL group. In a multivariate analysis that included each antibiotic, previous use of fluoroquinolone (OR, 7.32; 95% CI, 1.58 to 34.01;
P
= 0.011) was significantly associated with ESBL-producing
E. coli
. Of 101 isolates in which ESBLs and their molecular relationships were studied, all isolates produced ESBLs from the CTX-M family (CTX-M-14, 40 isolates; CTX-M-15, 39 isolates; and other members of the CTX-M family, 22 isolates). In conclusion, this study confirms that ESBL-producing
E. coli
strains are a notable cause of community onset infections in predisposed patients. HCA infection and previous use of fluoroquinolone were significant factors associated with ESBL-producing
E. coli
in community onset infections.
Strong Correlation between Liver and Serum Levels of Hepatitis C Virus Core Antigen and RNA in Chronically Infected Patients
Authors: Descamps V. , Op de Beeck A. , Plassart C. , Brochot E. , François C. , Helle F. , Adler M. , Bourgeois N. , Degré D. , Duverlie G. , Castelain S.
Published: December 2011

HCV core antigen (Ag) and HCV RNA levels were evaluated in matched liver biopsy samples and sera from 22 patients with hepatitis C infection by using the quantitative Architect HCV Ag immunoassay and a real-time RT-qPCR assay, respectively. The data showed a strong correlation between liver and serum compartments of HCV Ag levels (
r
= 0.80) and HCV RNA levels (
r
= 0.87). In summary, the serum HCV Ag and RNA levels reflect the intrahepatic values.
Viral Interferon Regulatory Factors Decrease the Induction of Type I and Type II Interferon during Rhesus Macaque Rhadinovirus Infection
Authors: Robinson Bridget A. , Estep Ryan D. , Messaoudi Ilhem , Rogers Kelsey S. , Wong Scott W.
Published: December 2011

Kaposi's sarcoma-associated herpesvirus and rhesus macaque rhadinovirus (RRV), two closely related gammaherpesviruses, are unique in their expression of viral homologs of cellular interferon regulatory factors (IRFs), termed viral IRFs (vIRFs). To assess the role of vIRFs duringde novoinfection, we have utilized the bacterial artificial chromosome clone of wild-type RRV17577(WTBACRRV) to generate a recombinant virus with all 8 of the vIRFs deleted (vIRF-ko RRV). The infection of primary rhesus fibroblasts and peripheral blood mononuclear cells (PBMCs) with vIRF-ko RRV resulted in earlier and increased induction of type I interferon (IFN) (IFN-α/β) and type II IFN (IFN-γ). Additionally, plasmacytoid dendritic cells maintained higher levels of IFN-α production in PBMC cultures infected with vIRF-ko RRV than in cultures infected with WTBACRRV. Moreover, the nuclear accumulation of phosphorylated IRF-3, which is necessary for the induction of type I IFN, was also inhibited following WTBACRRV infection. These findings demonstrate that duringde novoRRV infection, vIRFs are inhibiting the induction of IFN at the transcriptional level, and one potential mechanism for this is the disruption of the activation and localization of IRF-3.
Identification of Cell Surface Molecules Involved in Dystroglycan-Independent Lassa Virus Cell Entry
Authors: Shimojima Masayuki , Ströher Ute , Ebihara Hideki , Feldmann Heinz , Kawaoka Yoshihiro
Published: December 2011

Although O-mannosylated dystroglycan is a receptor for Lassa virus, a causative agent of Lassa fever, recent findings suggest the existence of an alternative receptor(s). Here we identified four molecules as receptors for Lassa virus: Axl and Tyro3, from the TAM family, and dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and liver and lymph node sinusoidal endothelial calcium-dependent lectin (LSECtin), from the C-type lectin family. These molecules enhanced the binding of Lassa virus to cells and mediated infection independently of dystroglycan. Axl- or Tyro3-mediated infection required intracellular signaling via the tyrosine kinase activity of Axl or Tyro3, whereas DC-SIGN- or LSECtin-mediated infection and binding were dependent on a specific carbohydrate and on ions. The identification of these four molecules as Lassa virus receptors advances our understanding of Lassa virus cell entry.
Selection and Accumulation of an HIV-1 Escape Mutant by Three Types of HIV-1-Specific Cytotoxic T Lymphocytes Recognizing Wild-Type and/or Escape Mutant Epitopes
Authors: Akahoshi Tomohiro , Chikata Takayuki , Tamura Yoshiko , Gatanaga Hiroyuki , Oka Shinichi , Takiguchi Masafumi
Published: December 2011

It is known that cytotoxic T lymphocytes (CTLs) recognizing HIV-1 escape mutants are elicited in HIV-1-infected individuals, but their role in the control of HIV-1 replication remains unclear. We investigated the antiviral ability of CTLs recognizing the HLA-A*24:02-restricted Gag28 -36 (KYKLKHIVW) epitope and/or its escape mutant (KYRLKHIVW) elicited in the early and chronic phases of the infection. Wild-type (WT)-epitope-specific CTLs, as well as cross-reactive CTLs recognizing both WT and K30R (3R) epitopes, which were predominantly elicited at early and/or chronic phases in HLA-A*24:02
+
individuals infected with the WT virus, suppressed the replication of the WT virus but failed to suppress that of the 3R virus, indicating that the 3R virus was selected by these 2 types of CTLs. On the other hand, cross-reactive and 3R-specific CTLs, which were elicited in those infected with the 3R virus, did not suppress the replication of either WT or 3R virus, indicating that these CTLs did not contribute to the control of 3R virus replication. High accumulation of the 3R mutation was found in a Japanese population recently recruited. The selection and accumulation of this 3R mutation resulted from the antiviral ability of these Gag28-specific CTLs and high prevalence of HLA-A*24:02 in a Japanese population. The present study highlighted the mechanisms for the roles of cross-reactive and mutant-epitope-specific CTLs, as well as high accumulation of escape mutants, in an HIV-1-infected population.
Intraspecific and interspecific interactions among proteins regulating exopolysaccharide synthesis in Streptococcus thermophilus, Streptococcus iniae, and Lactococcus lactis subsp. cremoris and the assessment of potential lateral gene transfer
Authors: Cefalo Angela D. , Broadbent Jeffery R. , Welker Dennis L.
Published: December 2011

Using the yeast two-hybrid system, intraspecific protein interactions were detected in Streptococcus iniae and Lactococcus lactis subsp. cremoris between the transmembrane activation protein (CpsC and EpsA, respectively) and the protein tyrosine kinase (CpsD and EpsB, respectively), between two protein tyrosine kinases, and between the protein tyrosine kinase and the phosphotyrosine phosphatase (CpsB and EpsC, respectively). For each of these intraspecific interactions, interspecific interactions were also detected when one protein was from S. iniae and the other was from Streptococcus thermophilus . Interactions were also observed between two protein tyrosine kinases when one protein was from either of the Streptococcus species and the other from L. lactis subsp. cremoris. The results and sequence comparisons performed in this study support the conclusion that interactions among the components of the tyrosine kinase – phosphatase regulatory system are conserved in the order Lactobacillales and that interspecific genetic exchanges of the genes that encode these proteins have the potential to form functional recombinants. A better understanding of intraspecific and interspecific protein interactions involved in regulating exopolysaccharide biosynthesis may facilitate construction of improved strains for industrial uses as well as identification of factors needed to form functional regulatory complexes in naturally occurring recombinants.
Purification and characterization of enterocin MC13 produced by a potential aquaculture probiontEnterococcus faeciumMC13 isolated from the gut ofMugil cephalus
Authors: Satish Kumar R. , Kanmani P. , Yuvaraj N. , Paari K.A. , Pattukumar V. , Arul V.
Published: December 2011

A bacteriocin producer strain MC13 was isolated from the gut of Mugil cephalus (grey mullet) and identified as Enterococcus faecium . The bacteriocin of E. faecium MC13 was purified to homogeneity, as confirmed by Tricine sodium dodecyl sulphate – polyacrylamide gel electrophoresis (SDS–PAGE). Reverse-phase high-performance liquid chromatography (HPLC) analysis showed a single active fraction eluted at 26 min, and matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry analysis showed the molecular mass to be 2.148 kDa. The clear zone in native PAGE corresponding to enterocin MC13 band further substantiated its molecular mass. A dialyzed sample (semicrude preparation) of enterocin MC13 was broad spectrum in its action and inhibited important seafood-borne pathogens: Listeria monocytogenes , Vibrio parahaemolyticus , and Vibrio vulnificus . This antibacterial substance was sensitive to proteolytic enzymes: trypsin, protease, and chymotrypsin but insensitive to catalase and lipase, confirming that inhibition was due to the proteinaceous molecule, i.e., bacteriocin, and not due to hydrogen peroxide. Enterocin MC13 tolerated heat treatment (up to 90 °C for 20 min). Enterococcus faecium MC13 was effective in bile salt tolerance, acid tolerance, and adhesion to the HT-29 cell line. These properties reveal the potential of E. faecium MC13 to be a probiotic bacterium. Enterococcus faecium MC13 could be used as potential fish probiotic against pathogens such as V. parahaemolyticus, Vibrio harveyi , and Aeromonas hydrophila in fisheries. Also, this could be a valuable seafood biopreservative against L. monocytogenes.
Molecular identification of a polyM-specific alginate lyase from Pseudomonas sp. strain KS-408 for degradation of glycosidic linkages between two mannuronates or mannuronate and guluronate in alginate
Authors: Kam Natania , Park Yoo Jung , Lee Eun Yeol , Kim Hee Sook
Published: December 2011

An alginate lyase gene of a newly isolated Pseudomonas sp. strain KS-408 was cloned by using PCR with the specific primers designed from homologous nucleotide sequences. A partial protein sequence of KS-408 alginate lyase was homology-modeled on the basis of the crystal structure of A1-III alginate lyase from Sphingomonas sp. strain A1. The proposed 3-D structure of KS-408 alginate lyase shows that Asn-198, His-199, Arg-246, and Tyr-253 residues are conserved for the catalytic active site. The recombinant KS-408-1F (with signal peptide) and KS-408-2F (without signal peptide) alginate lyases with the (His)6 tag consist of 393 (44.5 kDa) and 372 (42.4 kDa) amino acids with isoelectric points of 8.64 and 8.46, respectively. The purified recombinant KS-408 alginate lyase was very stable when it was incubated at 40 °C for 30 min. Alginate oligosaccharides produced by the KS-408-2F alginate lyase were purified on a Bio-Gel P2 column and analyzed by thin-layer chromatography, fast-protein liquid chromatography, and electrospray ionization mass spectrometry. 1H NMR data showed that the KS-408-2F alginate lyase cleaved the glycosidic linkages between two mannuronates (mannuronate-β(1–4)-mannuronate) or mannuronate and guluronate (mannuronate-β(1–4)-guluronate), indicating that the KS-408 alginate lyase is a polyM-specific lyase.
Arrestins 2 and 3 differentially regulate ETA and P2Y2 receptor-mediated cell signaling and migration in arterial smooth muscle
Authors: Morris Gavin E. , Nelson Carl P. , Brighton Paul J. , Standen Nicholas B. , Challiss R. A. John , Willets Jonathon M.
Published: December 2011

Overstimulation of endothelin type A (ETA) and nucleotide (P2Y) Gαq-coupled receptors in vascular smooth muscle causes vasoconstriction, hypertension, and, eventually, hypertrophy and vascular occlusion. G protein-coupled receptor kinases (GRKs) and arrestin proteins are sequentially recruited by agonist-occupied Gαq-coupled receptors to terminate phospholipase C signaling, preventing prolonged/inappropriate contractile signaling. However, these proteins also play roles in the regulation of several mitogen-activated protein kinase (MAPK) signaling cascades known to be essential for vascular remodeling. Here we investigated whether different arrestin isoforms regulate endothelin and nucleotide receptor MAPK signaling in rat aortic smooth muscle cells (ASMCs). When intracellular Ca2+ levels were assessed in isolated ASMCs loaded with Ca2+-sensitive dyes, P2Y2 and ETA receptor desensitization was attenuated by selective small-interfering (si)RNA-mediated depletion of G protein-coupled receptor kinase 2 (GRK2). Using similar siRNA techniques, knockdown of arrestin2 prevented P2Y2 receptor desensitization and enhanced and prolonged p38 and ERK MAPK signals, while arrestin3 depletion was ineffective. Conversely, arrestin3 knockdown prevented ETA receptor desensitization and attenuated ET1-stimulated p38 and ERK signals, while arrestin2 depletion had no effect. Using Transwell assays to assess agonist-stimulated ASMC migration, we found that UTP-stimulated migration was markedly attenuated following arrestin2 depletion, while ET1-stimulated migration was attenuated following knockdown of either arrestin. These data highlight a differential arrestin-dependent regulation of ETA and P2Y2 receptor-stimulated MAPK signaling. GRK2 and arrestin expression are essential for agonist-stimulated ASMC migration, which, as a key process in vascular remodeling, highlights the potential roles of GRK2 and arrestin proteins in the progression of vascular disease.
Differential N termini in epithelial Na+ channel δ-subunit isoforms modulate channel trafficking to the membrane
Authors: Wesch Diana , Althaus Mike , Miranda Pablo , Cruz-Muros Ignacio , Fronius Martin , González-Hernández Tomás , Clauss Wolfgang G. , Alvarez de la Rosa Diego , Giraldez Teresa
Published: December 2011

The epithelial Na+ channel (ENaC) is a heteromultimeric ion channel that plays a key role in Na+ reabsorption across tight epithelia. The canonical ENaC is formed by three analogous subunits, α, β, and γ. A fourth ENaC subunit, named δ, is expressed in the nervous system of primates, where its role is unknown. The human δ-ENaC gene generates at least two splice isoforms, δ1 and δ2 , differing in the N-terminal sequence. Neurons in diverse areas of the human and monkey brain differentially express either δ1 or δ2 , with few cells coexpressing both isoforms, which suggests that they may play specific physiological roles. Here we show that heterologous expression of δ1 in Xenopus oocytes and HEK293 cells produces higher current levels than δ2 . Patch-clamp experiments showed no differences in single channel current magnitude and open probability between isoforms. Steady-state plasma membrane abundance accounts for the dissimilarity in macroscopic current levels. Differential trafficking between isoforms is independent of β- and γ-subunits, PY-motif-mediated endocytosis, or the presence of additional lysine residues in δ2-N terminus. Analysis of δ2-N terminus identified two sequences that independently reduce channel abundance in the plasma membrane. The δ1 higher abundance is consistent with an increased insertion rate into the membrane, since endocytosis rates of both isoforms are indistinguishable. Finally, we conclude that δ-ENaC undergoes dynamin-independent endocytosis as opposed to αβγ-channels.
Processing and stability of type IIc sodium-dependent phosphate cotransporter mutations in patients with hereditary hypophosphatemic rickets with hypercalciuria
Authors: Haito-Sugino Sakiko , Ito Mikiko , Ohi Akiko , Shiozaki Yuji , Kangawa Natsumi , Nishiyama Takashi , Aranami Fumito , Sasaki Shohei , Mori Ayaka , Kido Shinsuke , Tatsumi Sawako , Segawa Hiroko , Miyamoto Ken-ichi
Published: December 2011

Mutations in the apically located Na+-dependent phosphate (NaPi) cotransporter, SLC34A3 (NaPi-IIc), are a cause of hereditary hypophosphatemic rickets with hypercalciuria (HHRH). We have characterized the impact of several HHRH mutations on the processing and stability of human NaPi-IIc. Mutations S138F, G196R, R468W, R564C, and c.228delC in human NaPi-IIc significantly decreased the levels of NaPi cotransport activities in Xenopus oocytes. In S138F and R564C mutant proteins, this reduction is a result of a decrease in the Vmax for Pi, but not the Km. G196R, R468W, and c.228delC mutants were not localized to oocyte membranes. In opossum kidney (OK) cells, cell surface labeling, microscopic confocal imaging, and pulse-chase experiments showed that G196R and R468W mutations resulted in an absence of cell surface expression owing to endoplasmic reticulum (ER) retention. G196R and R468W mutants could be partially stabilized by low temperature. In blue native-polyacrylamide gel electrophoresis analysis, G196R and R468W mutants were either denatured or present in an aggregation complex. In contrast, S138F and R564C mutants were trafficked to the cell surface, but more rapidly degraded than WT protein. The c.228delC mutant did not affect endogenous NaPi uptake in OK cells. Thus, G196R and R468W mutations cause ER retention, while S138F and R564C mutations stimulate degradation of human NaPi-IIc in renal epithelial cells. Together, these data suggest that the NaPi-IIc mutants in HHRH show defective processing and stability.
2-Hydroxyestradiol slows progression of experimental polycystic kidney disease
Authors: Anderson Sharon , Oyama Terry T. , Lindsley Jessie N. , Schutzer William E. , Beard Douglas R. , Gattone Vincent H. , Komers Radko
Published: December 2011

Male gender is a risk factor for progression of polycystic kidney disease (PKD). 17β-Estradiol (E2) protects experimentally, but clinical use is limited by adverse effects. Novel E2 metabolites provide many benefits of E2 without stimulating the estrogen receptor, and thus may be safer. We hypothesized that E2 metabolites are protective in a model of PKD. Studies were performed in male control Han:SPRD rats, and in cystic males treated with orchiectomy, 2-methoxyestradiol, 2-hydroxyestradiol (2-OHE), or vehicle, from age 3 to 12 wk. Cystic rats exhibited renal functional impairment (∼50% decrease in glomerular filtration and renal plasma flow rates, P < 0.05) and substantial cyst development (20.5 ± 2.0% of cortex area). 2-OHE was the most effective in limiting cysts (6.0 ± 0.7% of cortex area, P < 0.05 vs. vehicle-treated cystic rats) and preserving function, in association with suppression of proliferation, apoptosis, and angiogenesis markers. Downregulation of p21 expression and increased expression of Akt, the mammalian target of rapamycin (mTOR), and some of its downstream effectors were significantly reversed by 2-OHE. Thus, 2-OHE limits disease progression in a cystic rodent model. Mechanisms include reduced renal cell proliferation, apoptosis, and angiogenesis. These effects may be mediated, at least in part, by preservation of p21 and suppression of Akt and mTOR. Estradiol metabolites may represent a novel, safe intervention to slow progression of PKD.
Overexpression of cGMP-dependent protein kinase I (PKG-I) attenuates ischemia-reperfusion-induced kidney injury
Authors: Li Yanzhang , Tong Xiaopeng , Maimaitiyiming Hasiyeti , Clemons Kate , Cao Ji-Min , Wang Shuxia
Published: December 2011

cGMP-dependent protein kinase (PKG) is a multifunctional protein. Whether PKG plays a role in ischemia-reperfusion-induced kidney injury (IRI) is unknown. In this study, using an in vivo mouse model of renal IRI, we determined the effect of renal IRI on kidney PKG-I levels and also evaluated whether overexpression of PKG-I attenuates renal IRI. Our studies demonstrated that PKG-I levels (mRNA and protein) were significantly decreased in the kidney from mice undergoing renal IRI. Moreover, PKG-I transgenic mice had less renal IRI, showing improved renal function and less tubular damage compared with their wild-type littermates. Transgenic mice in the renal IRI group had decreased tubular cell apoptosis accompanied by decreased caspase 3 levels/activity and increased Bcl-2 and Bag-1 levels. In addition, transgenic mice undergoing renal IRI demonstrated reduced macrophage infiltration into the kidney and reduced production of inflammatory cytokines. In vitro studies showed that peritoneal macrophages isolated from transgenic mice had decreased migration compared with control macrophages. Taken together, these results suggest that PKG-I protects against renal IRI, at least in part through inhibiting inflammatory cell infiltration into the kidney, reducing kidney inflammation, and inhibiting tubular cell apoptosis.
Activation of renal angiotensin type 1 receptor contributes to the pathogenesis of progressive renal injury in a rat model of chronic cardiorenal syndrome
Authors: Homma Tsuyoshi , Sonoda Hiroko , Manabe Kenichi , Arai Kiyoshi , Mizuno Makoto , Sada Toshio , Ikeda Masahiro
Published: December 2011

Although chronic cardiac dysfunction is known to progressively exacerbate renal injury, a condition known as type 2 cardiorenal syndrome (CRS), the mechanism responsible is largely unknown. The present study was undertaken to clarify the mechanism of renal injury in rats with both unilateral nephrectomy (NX) and surgically induced myocardial infarction (MI), corresponding to a model of type 2 CRS. Compared with a control group, rats with both MI and NX (MI+NX) exhibited progressive proteinuria during the experimental period (34 wk after MI surgery), whereas proteinuria was not observed in rats with MI alone and was moderate in rats with NX alone. The proteinuria in rats with MI+NX was associated with renal lesions such as glomerulosclerosis and infiltration of mononuclear cells and upregulation of the renal proinflammatory and -fibrotic cytokine and angiotensin II type 1a receptor (AT1aR) genes. In contrast, plasma renin activity was lowered in rats with MI+NX. Immunohistochemistry revealed that the increased AT1R protein was present mainly in renal interstitial mononuclear cells. Olmesartan medoxomil, an AT1R blocker, markedly reduced the proteinuria and infiltration of mononuclear cells, whereas spironolactone, a mineralocorticoid receptor blocker, did not. The present findings demonstrate the pathogenetic role of renal interstitial AT1R signaling in a model of type 2 CRS, providing evidence that AT1R blockade can be a useful therapeutic option for this syndrome.
Heterogeneous firing behavior during ictal-like epileptiform activity in vitro
Authors: Andreasen Mogens , Nedergaard Steen
Published: December 2011

Seizure activity in vivo is caused by populations of neurons displaying a high degree of variability in activity pattern during the attack. The reason for this variability is not well understood. Here we show in an in vitro preparation that hippocampal CA1 pyramidal cells display four types of afterdischarge behavior during stimulus-induced ictal-like events in the presence of Cs+ (5 mM): type I (43.7%) consisting of high-frequency firing riding on a plateau potential; type II (28.2%) consisting of low-frequency firing with no plateau potential; type III (18.3%) consisting of high-frequency firing with each action potential preceded by a transient hyperpolarization and time-locked to population activity, no plateau potential; “passive” (9.9%) typified by no afterdischarge. Type I behavior was blocked by TTX (0.2 μM) and intracellular injection of QX314 (12.5–25 mM). TTX (0.2 μM) or phenytoin (50 μM) terminated ictal-like events, suggesting that the persistent Na+ current ( INaP) is pivotal for type I behavior. Type I behavior was not correlated to intrinsic bursting capability. Blockade of the M current ( IM) with linopirdine (10 μM) increased the ratio of type I neurons to 100%, whereas enhancing IM with retigabine (50–100 μM) greatly reduced the epileptiform activity. These results suggest an important role of IM in determining afterdischarge behavior through control of INaP expression. We propose that type I neurons act as pacemakers, which, through synchronization, leads to recruitment of type III neurons. Together, they provide the “critical mass” necessary for ictogenesis to become regenerative.
Dopaminergic neuromodulation of synaptic transmission between mitral and granule cells in the teleost olfactory bulb
Authors: Kawai Takafumi , Abe Hideki , Oka Yoshitaka
Published: December 2011

A growing body of evidence suggests that teleosts are important models for the study of neural processing of olfactory information, and the functional role of dopamine (DA), which is a potent neuromodulator endogenous to the mammalian olfactory bulb, has been one of the strongest focuses in this field. However, the cellular mechanisms of dopaminergic neuromodulation in olfactory bulbar neural circuits have not been fully understood. We investigated such mechanisms by using the goldfish, which offers several advantages for analyzing olfactory information processing by electrophysiological methods. First, we found in the olfactory bulb that numerous cell bodies of the dopaminergic neurons are mainly distributed in the mitral cell layer and extend fine processes to the glomerular layer. Next, we made in vitro field potential recordings and showed that synaptic transmissions from mitral to granule cells were suppressed by DA application. DA also increased the paired-pulse ratio, suggesting that the suppression of synaptic transmission is caused by a decrease in presynaptic glutamate release from the mitral cells. Furthermore, DA significantly suppressed the oscillatory activity of the olfactory bulb in response to olfactory stimuli. Although DA suppresses the synaptic inputs from the olfactory nerve to the olfactory bulbar neurons in mammals, this phenomenon was not observed in the goldfish. These findings indicate that suppression of the mitral to granule cell synaptic transmission in the reciprocal synapses plays an important role in the negative regulation of olfactory responsiveness in the goldfish olfactory bulb.
The Influence of Race on Employment Status and Earnings of African Immigrant Men in the United States
Authors: Djamba Yanyi K. , Kimuna Sitawa R.
Published: December 2011

This paper uses the labor queue theory to examine the changing influence of race on the employment status and earnings of African
immigrant men in the United States between 1980 and 2008. The results show that the white advantage echoed in previous research has diminished.
Black African immigrant men′s chance of being employed is now greater than that of their white counterparts when their sociodemographic
characteristics are taken into consideration. However, when human capital factors are included in the regression models, white African immigrant men
still maintain a significant advantage in earnings. This study also uncovered differential impacts of marriage and school enrollment on white and black
African immigrant men′s employment and earnings. These results challenge the use of labor queue theory as a framework for explaining
immigrants′ experience in the US job market.
A Convenient Method for Manufacturing TiO2Electrodes on Titanium Substrates
Authors: Qin Wei , Lu Songtao , Wu Xiaohong , Wang Song
Published: December 2011

Thin titanium dioxide films were successfully prepared on titanium plates in ammonium sulfate solution with the micro-plasma oxidation method. The thin TiO2films were sensitized with acis-RuL2(SCN)2⋅2H2O (L =cis-2,2′-bipyridine-4,4′-dicarboxlic acid) ruthenium complex, and implemented into a dye sensitized solar cell configuration. The influence of current density on the surface structure and photoelectric performance of the TiO2films was investigated. The results show that the thin TiO2films are porous, and the dye-sensitized solar cell based on the film prepared at 14 A/dm2has exhibited higher overall light-to-electricity conversion efficiencies of 0.095% under the illumination at 40 mW/cm2.
Some Recent Developments in Efficiency Measurement in Stochastic Frontier Models
Authors: Kumbhakar Subal C. , Tsionas Efthymios G.
Published: December 2011

This paper addresses some of the recent developments in efficiency measurement using stochastic frontier (SF) models in some selected areas. The following three issues are discussed in details. First, estimation of SF models with input‐oriented technical efficiency. Second, estimation of latent class models to address technological heterogeneity as well as heterogeneity in economic behavior. Finally, estimation of SF models using local maximum likelihood method. Estimation of some of these models in the past was considered to be too difficult. We focus on the advances that have been made in recent years to estimate some of these so‐called difficult models. We complement these with some developments in other areas as well.