bluuebunny/crossref_metadata_2025 huggingface dataset:
Proteolysis of the tumour suppressor hDlg in response to osmotic stress is mediated by caspases and independent of phosphorylation
Authors: Iñesta‐Vaquera Francisco A. , Centeno Francisco , del Reino Paloma , Sabio Guadalupe , Peggie Mark , Cuenda Ana
Published: December 2008

Human disc‐large (hDlg) is a scaffold protein critical for the maintenance of cell polarity and adhesion. hDlg is a component of the p38γ MAP kinase pathway, which is important for the adaptation of mammalian cells to changes in environmental osmolarity. Here we report a strong decrease in the levels of hDlg protein in the human epithelial cell line HeLa when exposed to osmotic shock. This is independent of the phosphorylation state of hDlg, is prevented by preincubating the cell with the caspase inhibitor z‐VAD and is part of the apoptotic process triggered by cellular stress. Although, both caspase 3 and caspase 6 are strongly activated by osmotic shock, the time course of caspase 6 activation parallels hDlg degradation, suggesting that this caspase may be responsible for the proteolysis. Mutating hDlg Asp747 to Ala abolishes caspase‐induced cleavage, but does not affect the early stage of apoptosis or cell attachment. Our findings show that osmotic stress triggers hDlg degradation through a mechanism different from the one mediated by proteasomes, and we identify hDlg as a caspase substrate during the apoptotic process, although its proteolysis may not be implicated in the progression of early apoptosis.
AN ANTIBODY MODIFIED AUTOMATED ENZYME‐LINKED IMMUNOSORBENT ASSAY‐BASED METHOD FOR DETECTION OF STAPHYLOCOCCAL ENTEROTOXIN*
Authors: BENNETT REGINALD W.
Published: December 2008

Studies were conducted with an automated enzyme‐linked immunosorbent assay (ELISA)‐based method (Vidas, Staph enterotoxin‐II [SET‐II]), exhibiting an antibody capture that had undergone modification by removal of the Fc fragment on the antibody. Raw liquid or shell eggs containing a nontoxin component with an attraction to the staphylococcal antienterotoxins were studied. Prior to ELISA testing, the eggs were homogenized and extracts collected by centrifugation. Studies showed that regardless of the ELISA‐based method used that utilized the unmodified antibodies with both the Fab1 + Fc fragments intact, positive (false positive) ELISA responses occurred with fertilized egg yolks and fertilized whole liquid or whole shell eggs. Conversely, when modified (Fab1) antibodies were used, the automated SET‐II enzyme‐linked fluorescent immunoassay was negative.

PRACTICAL APPLICATIONS

Most enzyme‐linked immunosorbent assays as well as other serological systems use the whole antibody that has not undergone modification for the detection of the staphylococcal enterotoxins. The use of whole antibody (Fab1 + Fc fragments) has on occasion produced false positive results. However, the antibody in which the Fc fragment has been removed leaving the Fab1 fragment provides a more specific antibody for the identification of this microbial toxin. The use of modified antibody (Fab1 fragment) represents significant improvement in antibody quality thus ensuring a greater degree of specificity without sacrificing the sensitivity of serological methods for the detection of staphylococcal enterotoxin in foods.
There's “Private” and Then There's “Private”: ERISA, Its Impact, and Options for Reform
Authors: Borzi Phyllis C.
Published: December 2008

For most of the first two decades after the enactment of the Employee Retirement Income Security Act of 1974 (ERISA), health policymakers did not seem to recognize the full impact that ERISA would have on regulation of health insurance and health care coverage. Perhaps the early court decisions in which the courts clarified that states could regulate insurance companies and the products they sold to ERISA plan sponsors gave them false comfort that because Congress appeared to recognize the role of the states in regulating insurance, ERISA might have only a tangential impact on health care reform efforts.
Reducing Racial, Ethnic, and Socioeconomic Disparities in Health Care: Opportunities in National Health Reform
Authors: Lillie-Blanton Marsha , Maleque Saqi , Miller Wilhelmine
Published: December 2008

As this nation embarks on new efforts to reform the U.S. health system, we face a critical unfinished agenda from the mid- 1960s: persistent racial, ethnic, and socioeconomic disparities in health and health care. Medicaid, Medicare, and Community Health Centers — public programs with very different legislative histories and financing mechanisms — were the first federally funded, nationwide efforts to improve health care access for low-income and elderly Americans. Members of racial and ethnic minority groups also greatly benefited from these efforts because recipients of federal funds, such as Medicare, were required to comply with the newly passed Civil Rights Act of 1964, which barred racial discrimination. Unquestionably, government played a major role in the gains in health care access that have occurred in the last half century. Yet today all Americans do not have the same opportunities for health, access to care, or quality of care when they receive it.
Nine Lessons for Health Reform: Or Will We Finally Learn from the Past?
Authors: Morone James A. , Blumenthal David
Published: December 2008

We stand on the edge of change. The Republican coalition is frayed, and its trusty issues — slash taxes, cut programs, deregulate industry, preach morals — have worn thin. Will the Democrats seize the opportunity and capture the political system? Or will Republicans refresh themselves and win a new lease on power? The contest will center on clashing visions and competing programs; since national health insurance is perhaps the Democrats’ signature program, health reform will be, once again, at the eye of the political storm.
Health Care Reform: Lessons from the Past, Lessons for the Future
Authors: Wilensky Gail R.
Published: December 2008

We are well into the political season that guarantees the election of a new president. Actually, this season, the election cycle began in November 2006, as soon as the off-year election ended. Not surprisingly, health care and reforming health care are major issues for the election — although somewhat less important than they were before late 2007.

I use the phrase “not surprisingly” because there are easily understandable reasons why health care tends to be an election issue whenever we are electing a new president. One obvious reason is that, for several decades, we have been plagued by sizeable numbers of people without health insurance and even more importantly, by unsustainable increases in health care spending and substantial numbers of people experiencing patient safety and clinical appropriateness problems. I regard the unsustainable spending and safety and quality problems as especially important because they affect all of us — not just the 15% of the population that is without health insurance.
Proving the Skeptics Wrong: Why Major Health Reform Can Happen despite the Odds
Authors: Jennings Chris
Published: December 2008

It comes as no surprise that, for the first time in nearly 15 years, a serious debate has emerged about the need to ensure quality, affordable coverage for all Americans. The statistics and stories about cost, coverage, and quality shortcomings abound and are indisputable. Setting the human consequences aside, the economic, budgetary competitiveness and demographic challenges facing the nation demand pragmatic and comprehensive reform. As health care costs (and cost-shifting from the uninsured) weigh down businesses and workers alike as well as federal, state, and local governments, stakeholders and forward-looking policymakers have started the drum-beat of reform — to the relief of most Americans.
(Uncontrolled) Donation after Cardiac Determination of Death: A Note of Caution
Authors: Doig Christopher James , Zygun David A.
Published: December 2008

“I think there’s a big strong belief in [...] the community … and maybe it’s in the world at large that somehow the doctors are more concerned about harvesting the organs than what’s best for the patient.”1 In the past 45 years, organ and tissue recovery and transplantation have moved from the occasional and experimental to a standard of care for end-stage organ failure; receiving an organ transplant is for many the only opportunity for increased quantity and/or quality of life. The increasing prevalence of diseases such as viral hepatitis, diabetes, and hypertension has significantly increased the incidence of end-organ failure. Additionally, surgical advances have permitted less stringent qualification criteria, so that people of advanced age or patients who may be in a physiologically fragile state are now eligible to be organ recipients. These changes have created a significant demand for organs.
Organ Donation after Circulatory Determination of Death: Lessons and Unresolved Controversies
Authors: Childress James F.
Published: December 2008

The several articles in this special issue on organ donation after circulatory determination of death or, as it is often put, donation after cardiac death (DCD), draw lessons from different kinds of experience in order to guide efforts in the U.S. to develop or refine policies for DCD. One lesson comes from a major and, by many measures, successful experimental DCD program in Washington, D.C. in the 1990s. Another lesson comes from European countries that have adopted presumed-consent legislation, a form of “opt out” that facilitates DCD as well as donation after neurological determination of death (DND). Another lesson, from the perspective of critical care medicine in Canada, attends to the implications of viewing a dying patient, undergoing resuscitative procedures, as a potential organ donor. A final lesson sketches implications of legislation and court cases in the U.S., often involving DND, for initiating temporary organ preservation (TOP) in DCD programs before consent has been obtained for organ donation. Some of these lessons are optimistic about the prospects for DCD, especially if certain steps are taken, while others are more cautious, particularly because of the costs and risks involved in DCD.
Preemption and the Obesity Epidemic: State and Local Menu Labeling Laws and the Nutrition Labeling and Education Act
Authors: Rutkow Lainie , Vernick Jon S. , Hodge James G. , Teret Stephen P.
Published: December 2008

Worldwide, obesity has become a major cause of preventable death, disease, and disability. While the epidemic of obesity is a significant public health issue in many developed nations, the United States has the highest prevalence of obesity among adults and children internationally. The National Health and Nutrition Examination Survey (NHANES) estimates that over 60 percent of U.S. adults are overweight or obese. According to the Centers for Disease Control and Prevention, “overweight” refers to adults whose body mass index (BMI), a number calculated using weight and height measurements, is between 25 and 29.9. “Obese” refers to adults whose BMI is 30 or higher. Among American children and adolescents, approximately 17 percent are overweight.
Influence of Water Temperature on Morphological Deformities in Cultured Larvae of Japanese Eel, Anguilla japonica, at Completion of Yolk Resorption
Authors: Kurokawa Tadahide , Okamoto Takuma , Gen Koichiro , Uji Susumu , Murashita Koji , Unuma Tatsuya , Nomura Kazuharu , Matsubara Hajime , Kim Shin‐Kwon , Ohta Hiromi , Tanaka Hideki
Published: December 2008

The occurrence of morphological deformities under different rearing water temperatures (18, 20, 22, 24, 26, 28, and 30 C) was examined in Japanese eel larvae. The rates of hatching and survival until yolk resorption at 22–26 C were higher than those at other water temperatures. Fertilized eggs never hatched at 18 and 30 C. The rates of occurrence of abnormal larvae reared at the water temperatures 24–28 C were lower than those at 20 or 22 C. Pericardial edema and lower jaw deformities occurred most frequently at lower temperatures (20 and 22 C). In contrast, the incubation temperature did not significantly affect the relative frequency of some neurocranial deformities and of spinal curvature. These results imply that the optimal temperatures for rearing Japanese eel eggs and embryos are 24–26 C from the viewpoints of survival and deformity.
Effects of Fish Size and Water Temperature on the Acute Toxicity of Copper for Japanese Flounder, Paralichthys olivaceus, and Red Sea Bream, Pagrus major
Authors: Furuta Takeshi , Iwata Nakahiro , Kikuchi Kotaro
Published: December 2008

The acute toxicities of copper were examined for Japanese flounder, Paralichthys olivaceus, and red sea bream, Pagrus major, in terms of fish size and water temperature. Artificial seawater of low pH of 5.4–6.7 was used as testing water to keep dissolved copper concentration at 0.04–41 mg Cu/L. Japanese flounder of 0.3–17 g and red sea bream of 0.5–13 g were exposed to different concentrations of copper for 96 h at 20 C under semistatic condition. Median‐lethal concentration for 96 h of Japanese flounder and red sea bream were 8.7–12.2 and 2.0–5.2 mg Cu/L, respectively. No significant relationships were observed between median‐lethal concentrations for 96 h and fish size for Japanese flounder, while the value decreased significantly with increasing fish size for red sea bream. Effect of water temperature on the acute toxicity was examined for Japanese flounder of 0.3 and 0.4 g at 10, 15, 20, and 25 C and red sea bream of 0.5 and 1.0 g at 12, 15, 20, and 25 C. Ninety‐six‐hour median‐lethal concentrations for Japanese flounder and red sea bream were 5.1–11.2 and 1.0–5.3 mg Cu/L, respectively. No significant relationships were observed between median‐lethal concentrations for 96 h and water temperature for both fish species.
NKCC1 (SLC12a2) induces a secondary axis in Xenopus laevis embryos independently of its co‐transporter function
Authors: Walters Zoë S. , Haworth Kim E. , Latinkic Branko V.
Published: December 2008

NKCC1 is a broadly expressed Na+–K+–Cl− co‐transporter involved in regulation of ion flux across the cell membrane and in regulating cell volume. Whilst much is known about the co‐transporter activity of NKCC1 and its regulation by protein kinases and phosphatases, little is known about the activities of NKCC1 that are co‐transporter independent. In this report we show that over‐expression of NKCC1 in embryos of Xenopus laevis induces secondary axes, independently of its co‐transporter activity. In addition, over‐expression of NKCC1 results in the formation of neural tissue in ectodermal explants. We also show that NKCC1 is expressed broadly but non‐uniformly in embryos of Xenopus laevis and Xenopus tropicalis, with prominent expression in the notochord, nervous system and stomach. These results provide insights into an additional, previously unreported activity of NKCCl.
Shakedown of a Thick Cylinder With a Radial Crosshole
Authors: Camilleri Duncan , Mackenzie Donald , Hamilton Robert
Published: December 2008

The shakedown behavior of a thin cylinder subject to constant pressure and cyclic thermal loading is described by the well known Bree diagram. In this paper, the shakedown and ratchetting behavior of a thin cylinder, a thick cylinder, and a thick cylinder with a radial crosshole is investigated by inelastic finite element analysis. Load interaction diagrams identifying regions of elastic shakedown, plastic shakedown, and ratchetting are presented. The interaction diagrams for the plain cylinders are shown to be similar to the Bree diagram. Incorporating a radial crossbore, Rc∕Ri=0.1 or less, in the thick cylinder significantly reduces the plastic shakedown boundary on the interaction diagram but does not significantly affect the ratchet boundary. The radial crosshole, for the geometry considered in this study, can be regarded as a local structural discontinuity and neglected when determining the maximum shakedown or (primary plus secondary stress) load in design by analysis. This may not be apparent to the design engineer, and no obvious guidance, for determining whether a crosshole is a local or global discontinuity, is given in the codes.
Prediction of Flow-Induced Vibrations in Tubular Heat Exchangers—Part I: Numerical Modeling
Authors: Khulief Y. A. , Al-Kaabi S. A. , Said S. A. , Anis M.
Published: December 2008

Flow-induced vibrations due to crossflow in the shell side of heat exchangers pose a problem of major interest to researchers and practicing engineers. Tube array vibrations may lead to tube failure due to fretting wear and fatigue. Such failures have resulted in numerous plant shutdowns, which are often very costly. The need for accurate prediction of vibration and wear of heat exchangers in service has placed greater emphasis on the improved modeling of the associated phenomenon of flow-induced vibrations. In this study, the elastodynamic model of the tube array is modeled using the finite element approach, wherein each tube is modeled by a set of finite tube elements. The interaction between tubes in the bundle is represented by fluidelastic coupling forces, which are defined in terms of the multidegree-of-freedom elastodynamic behavior of each tube in the bundle. Explicit expressions of the finite element coefficient matrices are derived. The model admits experimentally identified fluidelastic force coefficients to establish the final form of equations of motion. The nonlinear complex eigenvalue problem is formulated and solved to determine the onset of fluidelastic instability for a given set of operating parameters.
Semi-Infinite Target Penetration by Ogive-Nose Penetrators: ALEGRA/SHISM Code Predictions for Ideal and Nonideal Impacts
Authors: Bishop Joseph E. , Voth Thomas E.
Published: December 2008

The physics of ballistic penetration mechanics is of great interest in penetrator and countermeasure design. The phenomenology associated with these events can be quite complex, and a significant number of studies have been conducted ranging from purely experimental to “engineering” models based on empirical and/or analytical descriptions to fully coupled penetrator/target, thermomechanical numerical simulations. Until recently, however, there appears to be a paucity of numerical studies considering “nonideal” impacts (Goldsmith, 1999, “Non-Ideal Projectile Impact on Targets,” Int. J. Impact Eng., 22, pp. 95–395). The goal of this work is to demonstrate the SHISM algorithm implemented in the ALEGRA multimaterial arbitrary Lagrangian Eulerian code (Boucheron, et al., 2002, ALEGRA: User Input and Physics Descriptions, Version 4.2, SAND2002-2775, Sandia National Laboratories, Albuquerque, NM). The SHISM algorithm models the three-dimensional continuum solid mechanics response of the target and penetrator in a fully coupled manner. This capability allows for the study of nonideal impacts (e.g., pitch, yaw, and/or obliquity of the target/penetrator pair). In this work predictions using the SHISM algorithm are compared with previously published experimental results for selected ideal and nonideal impacts of metal penetrator-target pairs. These results show good agreement between predicted and measured maximum depths-of-penetration (DOPs), for ogive-nose penetrators with striking velocities in the 0.5–1.5 km/s range. Ideal impact simulations demonstrate convergence in predicted DOP for the velocity range considered. A theory is advanced to explain disagreement between predicted and measured DOPs at higher striking velocities. This theory postulates uncertainties in angle-of-attack for the observed discrepancies. It is noted that material models and associated parameters used here were unmodified from those in literature. Hence, no tuning of models was performed to match experimental data.
Multinormal In Vitro Distribution Model Suitable for the Distribution ofPlasmodium falciparumChemosusceptibility to Doxycycline
Authors: Briolant Sébastien , Baragatti Meili , Parola Philippe , Simon Fabrice , Tall Adama , Sokhna Cheikh , Hovette Philippe , Mamfoumbi Modeste Mabika , Koeck Jean-Louis , Delmont Jean , Spiegel André , Castello Jacky , Gardair Jean Pierre , Trape Jean Francois , Kombila Maryvonne , Minodier Philippe , Fusai Thierry , Rogier Christophe , Pradines Bruno
Published: December 2008

The distribution and range of 50% inhibitory concentrations (IC50s) of doxycycline were determined for 747 isolates obtained between 1997 and 2006 from patients living in Senegal, Republic of the Congo, and Gabon and patients hospitalized in France for imported malaria. The statistical analysis was designed to answer the specific question of whetherPlasmodium falciparumhas different phenotypes of susceptibility to doxycycline. A triple normal distribution was fitted to the data using a Bayesian mixture modeling approach. The IC50geometric mean ranged from 6.2 μM to 11.1 μM according to the geographical origin, with a mean of 9.3 μM for all 747 parasites. The values for all 747 isolates were classified into three components: component A, with an IC50mean of 4.9 μM (±2.1 μM [standard deviation]); component B, with an IC50mean of 7.7 μM (±1.2 μM); and component C, with an IC50mean of 17.9 μM (±1.4 μM). According to the origin of theP. falciparumisolates, the triple normal distribution was found in each subgroup. However, the proportion of isolates predicted to belong to component B was most important in isolates from Gabon and Congo and in isolates imported from Africa (from 46 to 56%). In Senegal, 55% of theP. falciparumisolates were predicted to be classified as component C. The cutoff of reduced susceptibility to doxycycline in vitro was estimated to be 35 μM.
Immunity to the Bacteriocin Sublancin 168 Is Determined by the SunI (YolF) Protein of
Bacillus subtilis
Authors: Dubois Jean-Yves F. , Kouwen Thijs R. H. M. , Schurich Anna K. C. , Reis Carlos R. , Ensing Hendrik T. , Trip Erik N. , Zweers Jessica C. , van Dijl Jan Maarten
Published: December 2008

Bacillus subtilis
strain 168 produces the extremely stable lantibiotic sublancin 168, which has a broad spectrum of bactericidal activity. Both sublancin 168 production and producer immunity are determined by the SPβ prophage. While the
sunA
and
sunT
genes for sublancin 168 production have been known for several years, the genetic basis for sublancin 168 producer immunity has remained elusive. Therefore, the present studies were aimed at identifying an SPβ gene(s) for sublancin 168 immunity. By systematic deletion analysis, we were able to pinpoint one gene, named
yolF
, as the sublancin 168 producer immunity gene. Growth inhibition assays performed using plates and liquid cultures revealed that YolF is both required and sufficient for sublancin 168 immunity even when heterologously produced in the sublancin-sensitive bacterium
Staphylococcus aureus
. Accordingly, we propose to rename
yolF
to
sunI
(for
su
blanci
n i
mmunity). Subcellular localization studies indicate that the SunI protein is anchored to the membrane with a single N-terminal membrane-spanning domain that has an N
out
-C
in
topology. Thus, the bulk of the protein faces the cytoplasm of
B. subtilis
. This topology has not yet been reported for known bacteriocin producer immunity proteins, which implies that SunI belongs to a novel class of bacteriocin antagonists.
Candidate Polyanionic Microbicides Inhibit Human T-Cell Lymphotropic Virus Type 1 Receptor Interactions, Cell-Free Infection, and Cell-Cell Spread
Authors: Romer Daniela , Brighty David W. , Robson Cynthia L. , Sattentau Quentin J.
Published: December 2008

The human T-cell lymphotropic virus type 1 (HTLV-1) is the cause of adult T-cell leukemia and inflammatory diseases including HTLV-1-associated myelopathy/tropical spastic paraparesis. HTLV-1 can be transmitted through sexual contact, mother-to-child transmission, and exposure to contaminated blood. Microbicides are agents that interfere with microbial infectivity at mucous membranes, and candidates are under development for use against sexually transmitted viruses such as human immunodeficiency virus type 1. We previously demonstrated that cell surface polyanionic heparan sulfate proteoglycans bind the HTLV-1 envelope glycoprotein surface subunit gp46, facilitating cell-cell and cell-free virus spread in vitro. We now show, using assays for Env-receptor binding inhibition, Env-induced cell-cell fusion, cell-cell virus spread, and pseudotype HTLV-1 infectivity, that the soluble polyanions PRO 2000 and dextran sulfate are potent inhibitors of HTLV-1 spread in vitro, with PRO 2000 being the more promising candidate. The results of these studies suggest that candidate topical microbicides may be of use in reducing HTLV-1 sexual transmission.
Optimized Method for Preparation of DNA from Pathogenic and Environmental Mycobacteria
Authors: Käser Michael , Ruf Marie-Thérèse , Hauser Julia , Marsollier Laurent , Pluschke Gerd
Published: December 2008

Genomic studies on pathogenic and environmental mycobacteria are of growing interest for understanding of their evolution, distribution, adaptation, and host-pathogen interaction. Since most mycobacteria are slow growers, material from in vitro cultures is usually scarce. The robust mycobacterial cell wall hinders both experimental cell lysis and efficient DNA extraction. Here, we compare elements of several DNA preparation protocols and describe a method that is economical and practical and reliably yields large amounts—usually 10-fold increased compared to earlier protocols—of highly pure genomic DNA for sophisticated downstream applications. This method was optimized for cultures of a variety of pathogenic and environmental mycobacterial species and proven to be suitable for direct mycobacterial DNA extraction from infected insect specimens.
Analysis of Dibenzothiophene Desulfurization in a Recombinant
Pseudomonas putida
Strain
Authors: Calzada Javier , Zamarro María T. , Alcón Almudena , Santos Victoria E. , Díaz Eduardo , García José L. , Garcia-Ochoa Felix
Published: December 2008

Biodesulfurization was monitored in a recombinant
Pseudomonas putida
CECT5279 strain. DszB desulfinase activity reached a sharp maximum at the early exponential phase, but it rapidly decreased at later growth phases. A model two-step resting-cell process combining sequentially
P. putida
cells from the late and early exponential growth phases was designed to significantly increase biodesulfurization.
Antimicrobial Resistance in
Escherichia coli
Isolates from Swine and Wild Small Mammals in the Proximity of Swine Farms and in Natural Environments in Ontario, Canada
Authors: Kozak Gosia K. , Boerlin Patrick , Janecko Nicol , Reid-Smith Richard J. , Jardine Claire
Published: December 2008

Wild animals not normally exposed to antimicrobial agents can acquire antimicrobial agent-resistant bacteria through contact with humans and domestic animals and through the environment. In this study we assessed the frequency of antimicrobial resistance in generic
Escherichia coli
isolates from wild small mammals (mice, voles, and shrews) and the effect of their habitat (farm or natural area) on antimicrobial resistance. Additionally, we compared the types and frequency of antimicrobial resistance in
E. coli
isolates from swine on the same farms from which wild small mammals were collected. Animals residing in the vicinity of farms were five times more likely to carry
E. coli
isolates with tetracycline resistance determinants than animals living in natural areas; resistance to tetracycline was also the most frequently observed resistance in isolates recovered from swine (83%). Our results suggest that
E. coli
isolates from wild small mammals living on farms have higher rates of resistance and are more frequently multiresistant than
E. coli
isolates from environments, such as natural areas, that are less impacted by human and agricultural activities. No
Salmonella
isolates were recovered from any of the wild small mammal feces. This study suggests that close proximity to food animal agriculture increases the likelihood that
E. coli
isolates from wild animals are resistant to some antimicrobials, possibly due to exposure to resistant
E. coli
isolates from livestock, to the resistance genes of these isolates, or to antimicrobials through contact with animal feed.
Simultaneous Analysis of Bacterioferritin Gene Expression and Intracellular Iron Status in
Pseudomonas putida
KT2440 by Using a Rapid Dual Luciferase Reporter Assay
Authors: Chen Shicheng , Bleam William F. , Hickey William J.
Published: December 2008

A dual luciferase reporter (DLR) system utilizing firefly and
Renilla
luciferases was developed and tested in a model rhizobacterium,
Pseudomonas putida
KT2440. The DLR was applied to simultaneously analyze expression of three putative bacterioferritin genes (
bfr
α,
bfr
β, and
bfr
) and assess the cellular iron status of strain KT2440 by monitoring expression of the Fur-regulated
fepA
-
fes
promoter. The DLR proved to be reproducible and sensitive. Expression of
bfr
α (PP0482) and
bfr
β (PP1082) was consistent with expectations for bacterioferritin and varied directly with the iron level. However, expression of
bfr
(PP4856) was inversely related to the iron concentration and it was thus more likely to encode a Dps-like protein rather than a bacterioferritin.
Phage Lysin LysK Can Be Truncated to Its CHAP Domain and Retain Lytic Activity against Live Antibiotic-Resistant Staphylococci
Authors: Horgan Marianne , O’Flynn Gary , Garry Jennifer , Cooney Jakki , Coffey Aidan , Fitzgerald Gerald F. , Ross R. Paul , McAuliffe Olivia
Published: December 2008

A truncated derivative of the phage endolysin LysK containing only the CHAP (cysteine- and histidine-dependent amidohydrolase/peptidase) domain exhibited lytic activity against live clinical staphylococcal isolates, including methicillin-resistant
Staphylococcus aureus
. This is the first known report of a truncated phage lysin which retains high lytic activity against live staphylococcal cells.
Characterization of Serine Proteinase Expression in
Agaricus bisporus
and
Coprinopsis cinerea
by Using Green Fluorescent Protein and the
A. bisporus SPR1
Promoter
Authors: Heneghan Mary N. , Porta Claudine , Zhang Cunjin , Burton Kerry S. , Challen Michael P. , Bailey Andy M. , Foster Gary D.
Published: December 2008

The
Agaricus bisporus
serine proteinase 1 (SPR1) appears to be significant in both mycelial nutrition and senescence of the fruiting body. We report on the construction of an SPR promoter::green fluorescent protein (GFP) fusion cassette, pGreen_hph1_SPR_GFP, for the investigation of temporal and developmental expression of SPR1 in homobasidiomycetes and to determine how expression is linked to physiological and environmental stimuli. Monitoring of
A. bisporus
pGreen_hph1_SPR_GFP transformants on media rich in ammonia or containing different nitrogen sources demonstrated that SPR1 is produced in response to available nitrogen. In
A. bisporus
fruiting bodies, GFP activity was localized to the stipe of postharvest senescing sporophores. pGreen_hph1_SPR_GFP was also transformed into the model basidiomycete
Coprinopsis cinerea
. Endogenous
C. cinerea
proteinase activity was profiled during liquid culture and fruiting body development. Maximum activity was observed in the mature cap, while activity dropped during autolysis. Analysis of the
C. cinerea
genome revealed seven genes showing significant homology to the
A. bisporus SPR1
and
SPR2
genes. These genes contain the aspartic acid, histidine, and serine residues common to serine proteinases. Analysis of the promoter regions revealed at least one CreA and several AreA regulatory motifs in all sequences. Fruiting was induced in
C. cinerea
dikaryons, and fluorescence was determined in different developmental stages. GFP expression was observed throughout the life cycle, demonstrating that serine proteinase can be active in all stages of
C. cinerea
fruiting body development. Serine proteinase expression (GFP fluorescence) was most concentrated during development of young tissue, which may be indicative of high protein turnover during cell differentiation.
Comparative Genomics Reveal Extensive Transposon-Mediated Genomic Plasticity and Diversity among Potential Effector Proteins within the GenusCoxiella
Authors: Beare Paul A. , Unsworth Nathan , Andoh Masako , Voth Daniel E. , Omsland Anders , Gilk Stacey D. , Williams Kelly P. , Sobral Bruno W. , Kupko John J. , Porcella Stephen F. , Samuel James E. , Heinzen Robert A.
Published: December 2008

Genetically distinct isolates ofCoxiella burnetii, the cause of human Q fever, display different phenotypes with respect to in vitro infectivity/cytopathology and pathogenicity for laboratory animals. Moreover, correlations betweenC. burnetiigenomic groups and human disease presentation (acute versus chronic) have been described, suggesting that isolates have distinct virulence characteristics. To provide a more-complete understanding ofC. burnetii's genetic diversity, evolution, and pathogenic potential, we deciphered the whole-genome sequences of the K (Q154) and G (Q212) human chronic endocarditis isolates and the naturally attenuated Dugway (5J108-111) rodent isolate. Cross-genome comparisons that included the previously sequenced Nine Mile (NM) reference isolate (RSA493) revealed both novel gene content and disparate collections of pseudogenes that may contribute to isolate virulence and other phenotypes. WhileC. burnetiigenomes are highly syntenous, recombination between abundant insertion sequence (IS) elements has resulted in genome plasticity manifested as chromosomal rearrangement of syntenic blocks and DNA insertions/deletions. The numerous IS elements, genomic rearrangements, and pseudogenes ofC. burnetiiisolates are consistent with genome structures of other bacterial pathogens that have recently emerged from nonpathogens with expanded niches. The observation that the attenuated Dugway isolate has the largest genome with the fewest pseudogenes and IS elements suggests that this isolate's lineage is at an earlier stage of pathoadaptation than the NM, K, and G lineages.
Genome-Wide Transposon Mutagenesis in Pathogenic
Leptospira
Species
Authors: Murray Gerald L. , Morel Viviane , Cerqueira Gustavo M. , Croda Julio , Srikram Amporn , Henry Rebekah , Ko Albert I. , Dellagostin Odir A. , Bulach Dieter M. , Sermswan Rasana W. , Adler Ben , Picardeau Mathieu
Published: December 2008

Leptospira interrogans
is the most common cause of leptospirosis in humans and animals. Genetic analysis of
L. interrogans
has been severely hindered by a lack of tools for genetic manipulation. Recently we developed the
mariner
-based transposon
Himar1
to generate the first defined mutants in
L. interrogans
. In this study, a total of 929 independent transposon mutants were obtained and the location of insertion determined. Of these mutants, 721 were located in the protein coding regions of 551 different genes. While sequence analysis of transposon insertion sites indicated that transposition occurred in an essentially random fashion in the genome, 25 unique transposon mutants were found to exhibit insertions into genes encoding 16S or 23S rRNAs, suggesting these genes are insertional hot spots in the
L. interrogans
genome. In contrast, loci containing notionally essential genes involved in lipopolysaccharide and heme biosynthesis showed few transposon insertions. The effect of gene disruption on the virulence of a selected set of defined mutants was investigated using the hamster model of leptospirosis. Two attenuated mutants with disruptions in hypothetical genes were identified, thus validating the use of transposon mutagenesis for the identification of novel virulence factors in
L. interrogans
. This library provides a valuable resource for the study of gene function in
L. interrogans
. Combined with the genome sequences of
L. interrogans
, this provides an opportunity to investigate genes that contribute to pathogenesis and will provide a better understanding of the biology of
L. interrogans
.
Crystal Structure of ORF12 fromLactococcus lactisPhage p2 Identifies a Tape Measure Protein Chaperone
Authors: Siponen Marina , Sciara Giuliano , Villion Manuela , Spinelli Silvia , Lichière Julie , Cambillau Christian , Moineau Sylvain , Campanacci Valérie
Published: December 2008

We report here the characterization of the nonstructural protein ORF12 of the virulent lactococcal phage p2, which belongs to theSiphoviridaefamily. ORF12 was produced as a soluble protein, which forms large oligomers (6- to 15-mers) in solution. Using anti-ORF12 antibodies, we have confirmed that ORF12 is not found in the virion structure but is detected in the second half of the lytic cycle, indicating that it is a late-expressed protein. The structure of ORF12, solved by single anomalous diffraction and refined at 2.9-Å resolution, revealed a previously unknown fold as well as the presence of a hydrophobic patch at its surface. Furthermore, crystal packing of ORF12 formed long spirals in which a hydrophobic, continuous crevice was identified. This crevice exhibited a repeated motif of aromatic residues, which coincided with the same repeated motif usually found in tape measure protein (TMP), predicted to form helices. A model of a complex between ORF12 and a repeated motif of the TMP of phage p2 (ORF14) was generated, in which the TMP helix fitted exquisitely in the crevice and the aromatic patches of ORF12. We suggest, therefore, that ORF12 might act as a chaperone for TMP hydrophobic repeats, maintaining TMP in solution during the tail assembly of the lactococcal siphophage p2.
Nanoarchaeal Origin of Histone H3?
Authors: Friedrich-Jahn Ulrike , Aigner Johanna , Längst Gernot , Reeve John N. , Huber Harald
Published: December 2008

NEQ288, one of two archaeal histones inNanoarchaeum equitans, has a unique four-residue insertion that closely resembles an insertion in the eukaryotic histone H3 lineage. NEQ288 bound DNA but did not compact DNA in vitro in the absence of NEQ348, the secondN. equitansarchaeal histone. The properties of NEQ288 suggest an intermediate between the archaeal and H3 histone lineages and an evolutionary step toward the now-mandatory assembly of eukaryotic histones into heterodimers.
The YvrI Alternative σ Factor Is Essential for Acid Stress Induction of Oxalate Decarboxylase in
Bacillus subtilis
Authors: MacLellan Shawn R. , Helmann John D. , Antelmann Haike
Published: December 2008

YvrI is a recently identified alternative σ factor in
Bacillus subtilis
that requires the coactivator YvrHa to activate transcription. Previously, a strain engineered to overproduce YvrI was found to overproduce oxalate decarboxylase (OxdC), and further analysis identified three YvrI-activated promoters preceding the
yvrI-yvrHa
,
yvrJ
, and
oxdC-yvrL
operons. Independently, proteome analyses identified OxdC as a highly abundant, cell wall-associated protein that accumulated under acidic growth conditions. We show here that the accumulation of OxdC in the cell wall proteome under acidic growth conditions is absolutely dependent on YvrI and is correlated with enhanced transcription of both the
yvrI-yvrHa
and the
oxdC-yvrL
operons. Conversely, OxdC accumulates to a high level even under nonacidic growth conditions in cells lacking YvrL, a negative regulator of YvrI/YvrHa-dependent transcription. These results indicate that YvrI and its associated coregulators YvrHa and YvrL are required for the regulation of OxdC expression by acid stress. The high-level accumulation of OxdC depends, in part, on a strong
oxdC
promoter. A regulatory sequence with similarity to an upstream promoter element (UP) was identified upstream of the
oxdC
promoter and is required for high-level promoter activity. Conservation of the YvrI/YvrHa/YvrL regulatory system among related species allowed us to deduce an expanded consensus sequence for the compositionally unusual promoters recognized by this new σ factor.
RESEARCH ON THE SPECIFIC VISCOSITY OF SEMI-CONCENTRATED FIBER SUSPENSIONS
Authors: WAN ZHANHONG , LIN JIANZHONG , YOU ZHENJIANG , DING HAI
Published: December 2008

The viscosity properties of the semi-concentrated suspensions of fibers with small aspect ratio were investigated in transient shear flow using a concentric cylinder geometry. Experimental results were compared with predictions by utilizing the constructive model developed by Batchelor in conjunction with the hybrid closure proposed by Advani and Tucker. To rectify the discrepancy between the theoretical prediction available at the present time and the measured data, a new expression for the specific viscosity in the semi-concentrated shear flows of fiber suspension is proposed allowing for the effects of the fiber–fiber interactions and the finite-aspect-ratio fiber. The results show that the model predictions for the fiber suspensions of different aspect ratio and concentration are fairly good.
INTEGRABLE HAMILTONIAN SYSTEMS RELATED TO THE AKNS SYSTEM WITH MATRIX POTENTIALS
Authors: QIN ZHENYUN , ZHOU ZIXIANG , ZHOU RUGUANG
Published: December 2008

In this paper, we extend the nonlinearization method to the AKNS system with matrix potentials for obtaining new finite-dimensional Hamiltonian systems. The Liouville complete integrability of these Hamiltonian systems is further shown by using involutive and independent motion integrals.
IMAGE AUTHENTICATION BASED ON FRACTAL FEATURES
Authors: LIAN SHIGUO
Published: December 2008

In this paper, the fractal features of natural images are used to construct an image authentication scheme, which can detect whether an image is maliciously tampered (cutting, wiping, modification, etc.) or not and can even locate the tampered regions. For the original image, the fractal transformation is applied to each of the image blocks, and some of the transformation parameters are quantized and used as the authentication code. The authentication code can be stored or transmitted secretly. To authenticate an image, the new authentication code is computed from the image with the similar method, and then compared with the stored or received code. A metric is proposed to decide whether an image block is tampered or not. Comparative experiments show that the authentication scheme can detect malicious tampering, is robust against such common signal processing as JPEG compression, fractal coding, adding noise or filtering, and thus, obtains competent performances compared with existing image authentication schemes.
ANALYSIS OF ULTRASONIC TRANSDUCERS WITH FRACTAL ARCHITECTURE
Authors: ORR LEIGH-ANN , MULHOLLAND ANTHONY J. , O'LEARY RICHARD L. , HAYWARD GORDON
Published: December 2008

Ultrasonic transducers composed of a periodic piezoelectric composite are generally accepted as the design of choice in many applications. Their architecture is normally very regular and this is due to manufacturing constraints rather than performance optimization. Many of these manufacturing restrictions no longer hold due to new production methods such as computer controlled, laser cutting, and so there is now freedom to investigate new types of geometry. In this paper, the plane wave expansion model is utilized to investigate the behavior of a transducer with a self-similar architecture. The Cantor set is utilized to design a 2-2 configuration, and a 1-3 configuration is investigated with a Sierpinski carpet geometry. Ideally a single longitudinal mode in the thickness direction will drive the transducer in a piston-like fashion. In this paper it was found that by increasing the fractal generation level, the bandwidth surrounding the main thickness mode will increase, but there will be a corresponding reduction in the amplitude of the electrical conductance. It is also shown that a shift in the frequency of operation of the device can be achieved by altering the spatial periodicity of the electrical excitation.
A GENERAL RESULT ON ABSOLUTE CONTINUITY OF NON-UNIFORM SELF-SIMILAR MEASURES ON THE REAL LINE
Authors: NEUNHÄUSERER JÖRG
Published: December 2008

We present a general result on absolute continuity of biased non-uniform self-similar measure on the real line, given by n different contraction and translation rates. The result holds generically in the sense of Lebesgue measure on a certain part of the parameter domain.
Phase evolution of MgB2 prepared under high pressure
Authors: Sun Yaxin , Yu Dongli
Published: December 2008

MgB2 superconductors were synthesized at high pressure and high temperature (HPHT) using pure Mg and B as raw materials. The effects of the experimental conditions such as pressure and temperature on phase evolution were studied using X-ray diffraction (XRD), scanning electron microscope (SEM), and DC magnetization techniques. Results showed that high pressure and high temperature are two important factors for synthesizing the
MgB2 phase. Stable
MgB2 can be most effectively obtained in a pressure-temperature region from 3 to 6 GPa and between the melting points of Mg up to 1100 to 1300 °C.
MgB2 starts to decompose into
MgB4 at higher temperatures and pressures. The decomposition temperature of
MgB2 increases with increasing pressure. The superconducting transition temperature Tc(bulk) was measured to be 38.0 to 38.8 K for
MgB2 prepared at 900 to 1000 °C under 3 GPa. The larger grains and better crystalline perfection contribute to the higher Tc(bulk) and the narrower ΔT.
Evolving Networks with Enhanced Stability Properties
Authors: Newth David , Ash Jeff
Published: December 2008

We use a search algorithm to identify networks with enhanced linear stability properties in this account. We then analyze these networks for topological regularities that explain the source of their stability/instability. Analysis of the structure of networks with enhanced stability properties reveals that these networks are characterized by a highly skewed degree distribution, very short path‐length between nodes, little or no clustering, and dissasortativity. By contrast, networks with enhanced instability properties have a peaked degree distribution with a small variance, long path‐lengths between nodes, a high degree of clustering, and high assortativity. We then test the topological stability of these networks and discover that networks with enhanced stability properties are highly robust to the random removal of nodes, but highly fragile to targeted attacks, while networks with enhanced instability properties are robust to targeted attacks. These network features have implications for the physical and biological networks that surround us.
Nickel(II) Complexes of Hydrazone of Isoniazid and Their Magneto‐Spectral, Electrochemical, Thermal and Antimicrobial Investigations
Authors: Prasad Surendra , Agarwal Ram K.
Published: December 2008

The synthesis of novel nickel(II) complexes with new ligand derived from hydrazone of isoniazid has been reported. The complexes have general compositions [Ni(L)2X2] or , where L = N‐isonicotinamido‐furfuraldimine (INH‐FFL) and X = Cl− or NCS−. The ligand hydrazone behaves as neutral bidentate (N and O donor) through the carbonyl oxygen and azomethine nitrogen. On the basis of elemental analysis, molecular weight determinations, magnetic susceptibility/moment, thermogravimetric, electrochemical, and spectroscopic studies, the new complexes have been characterized with octahedral geometry. The antibacterial and antifungal studies of the present complexes show that they are moderate antibacterial and antifungal agents.