bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphotropic Phase Boundary of Sodium–Potassium Niobate Lead‐Free Piezoelectric Ceramics
Authors: Pang Xuming , Qiu Jinhao , Zhu Kongjun
Published: October 2010

Based on the empirical electron theory of solids and molecules, the valence‐electron structures (VES) of sodium–potassium niobate ((KxNa1−x)NbO3) were calculated, and the relationship between the VES and the piezoelectric properties was determined. The results indicate that the piezoelectric constants are continuous and equal in the composition range of 0.4≤x≤0.5. The piezoelectric properties do not dramatically improved in the so‐called morphotropic phase boundary (MPB). The experimental results show that the change trend of the piezoelectric constants is in good agreement with the calculation results. Contrary to traditional MPB, the so‐called MPB of (KxNa1−x)NbO3 has no significant influence on the piezoelectric and ferroelectric properties. In other words, it was speculated that the existence of the traditional MPB was possibly controvertible in the KNN system.
The relationship between early embryo development and tumourigenesis
Authors: Ma Yanlei , Zhang Peng , Wang Feng , Yang Jianjun , Yang Zhe , Qin Huanlong
Published: October 2010

Introduction

Embryonic origin of cancer

Similarity in cell invasive behaviours

Similarity in epigenetic regulation

Similarity in gene expression

Similarity in protein profiling

Similarity in other biological behaviours

Conclusion

With the recent substantial progress in developmental biology and cancer biology, the similarities between early embryo development and tumourigenesis, as well as the important interaction between tumours and embryos become better appreciated. In this paper, we review in detail the embryonic origin of tumour, and the similarities between early embryo development and tumourigenesis with respect to cell invasive behaviours, epigenetic regulation, gene expression, protein profiling and other important biological behaviours. Given an improved understanding of the relationship between early embryo development and tumourigenesis, now we have better and broader resources to attack cancer from the perspective of developmental biology and develop next generation of prognostic and therapeutic approaches for this devastating disease.
Does autophagy take a front seat in lifespan extension?
Authors: Petrovski Goran , Das Dipak K.
Published: October 2010

Introduction

Signalling cascades regulating the ageing process

Ageing and autophagy

Signalling cascades regulating autophagy

Pharmacological manipulations to induce autophagy

Future perspectives

This review focuses on the interrelationship between ageing and autophagy. There is a striking similarity between the signalling aspects of these two processes. Both ageing and autophagy involve several of the signalling components such as insulin/IGF‐1, AMPK, Ras‐cAMP‐PKA, Sch9 and mTOR. Ageing and ageing‐mediated defective autophagy involve accumulation of lipofuscin. Components of anti‐ageing and autophagy include SirTs and FoxOs. Nutritional deprivation or calorie restriction as well as several nutriceuticals including resveratrol, spermidine, curcumin and piperine can enhance autophagy and increase lifespan. Such striking similarities indicate that lifespan is strongly dependent on autophagy.
Is there a reduction of congenital abnormalities in the offspring of diabetic pregnant women after folic acid supplementation? A population‐based case‐control study
Authors: Bánhidy Ferenc , Dakhlaoui Abdallah , Puhó Erzsébet H. , Czeizel Andrew A. E.
Published: October 2010

The objective of the present study was to estimate the preventive effect of folic acid for structural birth defects (i.e. congenital abnormalities [CAs]) in the offspring of pregnant women with diabetes mellitus type 1 (DM‐1). The occurrence of medically recorded DM‐1 in pregnant women who had malformed fetuses/newborns (cases) and delivered healthy babies (controls) with or without folic acid supplementation was compared in the population‐based Hungarian Case‐Control Surveillance System of Congenital Abnormalities. The case group included 22 843 offspring, and there were 79 (0.35%) pregnant women with DM‐1, while the control group comprised of 38 151 newborns, and 88 (0.23%) had mothers with DM‐1. Case mothers with DM‐1 associated with a higher risk of total rate of CAs in their offspring (OR with 95% CI: 1.5, 1.1–2.0) compared to the total rate of CAs in the offspring of non‐diabetic case mothers. This higher risk can be explained by four specific types/groups of CAs: isolated renal a/dysgenesis; obstructive CA of the urinary tract; cardiovascular CAs; and multiple CAs, namely caudal dysplasia sequence. However, there was no higher rate of total CAs in the children of pregnant women with DM‐1 after folic acid supplementation; in addition, neural‐tube defect and renal a/dysgenesis did not occur. However, this benefit cannot be explained by the CA reduction effect of folic acid during the critical period of major CAs. In conclusion, there was a certain reduction in maternal teratogenic effect of DM‐1 after folic acid supplementation during pregnancy, but the explanation of this effect requires further study.
Bilateral simultaneous acute angle closure glaucoma precipitated by non‐prescription cold and flu medication
Authors: Rudkin Adam K , Gray Tim L , Awadalla Mona , Craig Jamie E
Published: October 2010

We present a case of a 63‐year‐old woman who presented to an ED with bifrontal headache, nausea and vomiting and reduced visual acuity. Examination revealed bilateral elevated intraocular pressures, corneal haze, shallow anterior chambers and poorly reactive, mid‐dilated pupils. Diagnosis was made of simultaneous bilateral acute angle closure glaucoma. A complete drug history revealed that she had been using an over‐the‐counter cold and flu remedy whose active ingredients included atropa belladonna, an herb with anticholinergic properties. It is likely that drug‐induced dilatation of the individual's pupils precipitated this angle closure emergency. In the report we discuss the risk factors for angle closure glaucoma, and review the local and systemic drugs known to trigger this sight‐threatening emergency.
Public criminologies
Authors: Uggen Christopher , Inderbitzin Michelle
Published: October 2010

Research Summary

Public scholarship aspires to bring social science home to the individuals, communities, and institutions that are its focus of study. In particular, it seeks to narrow the yawning gap between public perceptions and the best available scientific evidence on issues of public concern. Yet nowhere is the gap between perceptions and evidence greater than in the study of crime. Here, we outline the prospects for a public criminology, conducting and disseminating research on crime, law, and deviance in dialogue with affected communities. We present historical data on the media discussion of criminology and sociology, and we outline the distinctive features of criminology—interdisciplinary, a subject matter that incites moral panics, and a practitioner base actively engaged in knowledge production—that push the boundaries of public scholarship.

Policy Implications

Discussions of public sociology have drawn a bright line separating policy work from professional, critical, and public scholarship. As the research and policy essays published in Criminology & Public Policy make clear, however, the best criminology often is conducted at the intersection of these domains. A vibrant public criminology will help to bring new voices to policy discussions while addressing common myths and misconceptions about crime.
Policing the homeless
Authors: Berk Richard , MacDonald John
Published: October 2010

Research Summary

Police officials across the United States are increasingly relying on place‐based approaches for crime prevention. In this article, we examine the Safer Cities Initiative, a widely publicized place‐based policing intervention implemented in Los Angeles's “Skid Row” that focused on crime and disorder associated with homeless encampments. Crime reduction was the goal. The police division in which the program was undertaken provides 8 years of time‐series data serving as the observations for the treatment condition. Four adjacent police divisions in which the program was not undertaken provide 8 years of time‐series data serving as the observations for the comparison condition. The data are analyzed using a generalized additive model. On balance, we find that this place‐based intervention is associated with meaningful reductions in violent, property, and nuisance street crimes. There is no evidence of crime displacement.

Policy Implications

This study provides further evidence that geographically targeted police interventions can lead to significant crime prevention benefits, with no evidence that crime is simply displaced to other areas. Criminologists and the media have given the Los Angeles Police Department (LAPD) little credit for major reductions in crime that have occurred during the past 5 years following a number of major policy reforms. We suggest that researchers should look more closely at the targeted interventions the LAPD has undertaken for evidence‐based examples of effective policing. Importantly, this work suggests that crime associated with homeless encampments can be meaningfully reduced with targeted police actions. However, law enforcement actions do not address the roots of homelessness nor most of its consequences. Getting tough on the homeless should not be confused with policies or programs that respond fundamentally to the social and personal problems that homelessness presents.
Platelet–leukocyte interactions link inflammatory and thromboembolic events in ischemic stroke
Authors: Franks Zechariah G. , Campbell Robert A. , Weyrich Andrew S. , Rondina Matthew T.
Published: October 2010

Stroke is a common and often fatal event, and, in survivors, it is accompanied by a high risk of recurrence. Ischemic stroke is associated with abnormal platelet activity and thrombus formation. In addition to their roles in the development of acute thrombi, platelets serve as a bridge for leukocytes within the vasculature. Myeloid leukocytes are critical mediators of atherosclerosis and atherothrombosis. Interactions between platelets and leukocytes foster an inflammatory and thrombotic milieu that influences lesion progression, facilitates plaque rupture, and triggers thrombus formation and embolization. Accordingly, antiplatelet agents, including aspirin, dipyridamole, and clopidogrel, are recommended therapies for most patients with a history of stroke. In addition to mitigating thrombosis, antiplatelet drugs have direct and indirect effects on inflammation, which may translate to enhanced clinical efficacy.
The challenge of mixed cerebrovascular disease
Authors: Fisher Mark
Published: October 2010

Stroke in general, and ischemic stroke in particular, are routinely defined using clinical criteria. Incorporating brain imaging and neuropathological findings into an expanded conceptual definition of stroke will result in a vastly increased prevalence of the disease. The resultant category of mixed cerebrovascular disease thus may include subclinical infarct, cerebral white matter disease, and cerebral microbleeds. Subclinical brain infarcts occur five times more frequently than does clinical ischemic stroke. Abnormalities of cerebral white matter are present in more than 95% of the population over the age of 65 years, and magnetic resonance imaging evidence of cerebral microbleeds is found in at least 18% of the population, beginning at the age of 60 years. Pathologic evidence supports at least a partial microvascular origin for cerebral white matter disease and cerebral microbleeds. Emphasizing mixed cerebrovascular disease as a conceptual framework allows for a focus on common underlying mechanisms and new therapeutic strategies.
Antioxidant and Antiradical Capacities in Apricot (Prunus armeniaca L.) Fruits: Variations from Genotypes, Years, and Analytical Methods
Authors: Hegedú´s Attila , Engel Rita , Abrankó László , Balogh Emó´ke , Blázovics Anna , Hermán Rita , Halász Júlia , Ercisli Sezai , Pedryc Andrzej , Stefanovits‐Bányai Éva
Published: October 2010

Abstract:  The fruit quality parameters and antioxidant capacity (ferric reducing antioxidant power, FRAP) and total phenolic content (TPC) were determined in 27 apricot cultivars and hybrids of diverse origins. Twenty one‐ to 35‐fold variations were measured among FRAP and TPC values. Besides genotype, harvest year also contributed significantly (P ≤ 0.05) to the variations of TPC presumably due to the climatic differences between years. A subset of genotypes (15) was also analyzed for their antiradical activities (2,2′‐diphenyl‐1‐picrylhydrazyl, DPPH; total radical‐scavenging activity, TRSA; water‐soluble antioxidant capacity, ACW; and lipid‐soluble antioxidant capacity, ACL), and vitamin C contents as well as color indices (CIE H°, L*, and chroma). The hybrid “Preventa” had outstanding FRAP (>10.4 mmol ascorbic acid/L), DPPH (74.45%), TRSA (0.002%), ACW (33587.5 nmol AA/L) and ACL (78.65 nmol Trolox/L), TPC (>2890.0 mg gallic acid/L), and vitamin C (16.17 mg/100 g FW) levels and an average carotenoid content estimated from the hue angle (66.99°). Most antioxidant and antiradical activities correlated significantly except for TRSA; the closest correlation was observed between FRAP and ACW (r = 0.952). Only TRSA showed significant correlations with color indices, H° and chroma, suggesting TRSA measures at least a fraction of the antioxidant capacity attributable to apricot carotenoids.

Practical Application:  The information presented might be directly used for developing apricot‐based functional foods.
Clinical features of Wilson disease: Analysis of 10 cases
Authors: Takeyama Yasuaki , Yokoyama Keiji , Takata Kazuhide , Tanaka Takashi , Sakurai Kunitoshi , Matsumoto Teruo , Iwashita Hideyuki , Ueda Shu‐ichi , Hirano Genryu , Hanano Takayuki , Nakane Hidetoshi , Morihara Daisuke , Nishizawa Shinya , Yoshikane Makoto , Anan Akira , Kakumitsu Shigeru , Kitamura Yuji , Sakamoto Masaharu , Irie Makoto , Iwata Kaoru , Shakado Satoshi , Sohda Tetsuro , Watanabe Hiroshi , Hirose Shinichi , Hayashi Hideyuki , Noritomi Tomoaki , Yamashita Yuichi , Sakisaka Shotaro
Published: October 2010

Aim:  The diagnosis of Wilson disease is based on the results of several clinical and biochemical tests. This study aimed to clarify the clinical features and spectrum of Wilson disease, including severe Wilson disease.

Methods:  Between 1985 and 2009, 10 patients with clinical, biochemical or histological evidence of Wilson disease were either diagnosed or had a previously established diagnosis confirmed at Fukuoka University Hospital. Severe Wilson disease was defined by a serum prothrombin time ratio of more than 1.5 or serum prothrombin activity of less than 50%. The 10 Wilson disease patients were divided into two groups, one containing three non‐severe patients and the other containing seven severe patients, and the biochemical features of the patients in these two groups were compared.

Results:  The mean age at diagnosis was 21.5 ± 11.7 years (range, 7–39). Decreased serum ceruloplasmin, enhanced 24‐h urinary copper excretion, presence of Kayser–Fleischer rings and histological signs of chronic liver damage were confirmed in 100%, 100%, 66.7% and 100% of patients, respectively. Severe Wilson disease patients had higher levels of serum ceruloplasmin and serum copper (P < 0.05, P < 0.05, respectively) than non‐severe patients.

Conclusion:  In severe Wilson disease patients, the serum ceruloplasmin and serum copper levels were higher than those in non‐severe Wilson disease patients.
Rolling Moment Characteristic Analysis of Wrap-Around Fins
Authors: Xin-Hong Chen , Run-Xiang Zhao
Published: October 2010

A lot of numerical and experimental studies indicate that wrap-around fin configuration exhibits a self-induced rolling moment even at angle of attack zero. It depends on the unequal pressure distributions over both sides of the fin. In this paper, we try to prove this special aerodynamic characteristic with a theoretical method. According to the transonic small perturbation potential theory, as well as the transonic small perturbation potential equation, this paper found the expressions of the wrap-around fin convexity and the concave pressure coefficient at subsonic and supersonic by solving the Laplace equation and the Bessel function of imaginary argument, and analyze the phenomena of wrap-around fin rolling moment generation at angle of attack zero, and discuss the reason. The flow field of a projectile with wrap-around fins is solved by numerical method to check the pressure distributions of the two surfaces of the wing at subsonic and supersonic, respectively. The computational result is accordant to the theoretical analysis results. It is proved that the complicated pressure distribution of the wing surfaces leads to the particular characteristic of rolling moment.
Penetration of Porous Jets
Authors: Hirsch Eitan , Mayseless Meir
Published: October 2010

Jets that emanate from high density porous liners are most widely used for penetration into Earth materials. These shaped-charges differ from those that contain solid copper liners in three major aspects: the porosity, the usually higher initial density, and the very short standoff in which they typically operate. Because penetration depth is commonly very difficult to increase by means of high density solid liners, it is important to understand the benefit of using porous liners in utilization of high density materials. The models published so far to describe the performance of jets formed by porous liners are based on the modification of the virtual origin model to suit this special case, which limits the accuracy of their predictions. Here we present a more general analysis that does not depend on the virtual origin assumption. Our study employs the SCAN semi-analytical code into which a new model for porous jet behavior is incorporated. It is used to explain the benefit of using this type of liner for oil-well penetration, hence penetration into low density targets, as opposed to penetration into hard steel.
Study on Expansion Process and Interaction of High Speed Twin Combustion-Gas Jets in Liquid
Authors: Yu Yonggang , Yan Shanheng , Zhao Na , Lu Xin , Zhou Yanhuang
Published: October 2010

The multilevel stepped-wall and rectangular observation chambers are designed to study the multipoint ignition process and the combustion stability control mechanism of the bulk-loaded liquid propellant gun. The expansion process and interaction of high-speed twin combustion-gas jets in liquid are studied by means of a high-speed digital camera system. The influence of the nozzle diameter, dual-orifice interval, jet pressure, and chamber structure on the jet expansion shape is discussed. The results indicate that a larger ratio of diameter-to-length can suppress the jet instability in stepped-wall chambers. Higher axial expansion velocity is found under the larger injection pressure, which it increases the instability of jet expansion process. Compared with a rectangular chamber, the axial expansion velocity is smaller, and the radial expansion velocity is larger in stepped-wall chambers under the same conditions. The theoretical studies of interaction of the gas jet with liquid were developed based on the experiment. Two-dimensional unsteady models are used to get the pressure, density, and velocity contours. The numerical simulation results coincide well with the experiment.
Analysis of Dynamic Characteristics for Rarefaction Wave Gun During the Launching
Authors: Zhang Xiao-bing , Wang Ying-ze
Published: October 2010

Rarefaction wave gun (RAVEN) propulsion has renewed interest in the fundamental limits of recoil reductions attainable by redirecting propellant gases rearward from a gun without compromising the projectile propulsion. Compared with a conventional gun there is a great difference in the launch process and launch structure. This paper is concerned with an analysis of the dynamic characteristics of this high performance weapon system by numerical simulation. Based on its launch mechanism and launch structure, the vibration equation describing the vibration characteristics of RAVEN was established by vibration theory, which considered the actual movement of the projectile and inertial breech by coupling the interior ballistic equations of the rarefaction wave gun. A rigid-flexible dynamic model, which considered the coupling effect between the elastic vibration of the launch barrel and the dynamic behaviors of the other parts of the RAVEN, is established via a subsystem method. The vibration response of RAVEN during the launch is analyzed by numerical simulation. Comparisons are presented based on the conventional gun, as well as the rules of how the different parameters affect the vibration response. During the launching of RAVEN, the launch barrel shows significant vibration due to the effect of the propellant gases, the inertial breech, and the projectile, and there is some reduction in the vibration amplitude compared with that observed in a conventional closed chamber gun. The vibration amplitude and duration of the launch barrel, which increased with a decrease in the loading density, an increase in the mass of the inertial breech and projectile, and a delay of the venting time, is affected in a more significant manner by changes in loading density and the mass of projectile. The coupled effect between the launch barrel and the other parts of RAVEN are most prevalent in the z-direction. The vibration amplitude along the z-direction is higher than that of the y-direction. When the coupled effect is considered, the transverse vibration response of the flexible barrel has some reduction compared with the one that does not exhibit the coupling effect.
A Method for Reduction in the Start-Up Time of a Bubbling Bed Boiler Combustor
Authors: Jain Vijay , Basu Prabir , Groulx Dominic
Published: October 2010

A study on the heating of inert bed solids in a bubbling fluidized bed by means of an over-bed start-up oil burner is presented in this paper. Experiments carried out in a 160 mm diameter bed shows that the bed heats up nonlinearly with time. The rate of heating and the peak temperature reached by the bed solids depend on the bed depth, the mean particle size, and the superficial velocity through the bed. It was further noted that premixing a certain amount of biomass with the inert bed solids accelerates the rate of heating, as well as increase the peak temperature attained. The internal heat generation in the biomass is found to start at temperatures as low as 200°C. Thus, premixing some biomass with inert bed materials could reduce the combustion start-up time of a fluidized bed boiler, reducing at the same time the start-up cost by saving on consumption of expensive fuel oil in the burner. Experimental data in the present laboratory-scale unit shows good agreement with those obtained earlier in an industrial fluidized bed tested with waste-coal.
Inorganic Nanoparticles as Protein Mimics
Authors: Kotov Nicholas A.
Published: October 2010

Inorganic nanoparticles coated with organic films can display surface chemistries that allow them to function like globular proteins.
Two Histone Marks Establish the Inner Centromere and Chromosome Bi-Orientation
Authors: Yamagishi Yuya , Honda Takashi , Tanno Yuji , Watanabe Yoshinori
Published: October 2010

Location, Location, Location

Cell division is orchestrated by a complex signaling pathway that ensures the correct segregation of newly replicated chromosomes to the two daughter cells. The pathway is controlled in part by restricting the activity of critical regulators to specific subcellular locations. For example, the chromosomal passenger complex (CPC) is recruited to chromosomes during mitosis where it oversees kinetochore activity and cytokinesis (see Perspective by

Musacchio

).

Wang
et al.

(p.
231
, published online 12 August),

Kelly
et al.

(p.
235
, published online 12 August), and

Yamagishi
et al.

(p.
239
) now show that the phosphorylation of the chromatin protein, histone H3, acts to bring the CPC to chromosomes, thereby activating its aurora B kinase subunit. The Survivin subunit of CPC binds specifically to phosphorylated H3, with the phosphorylation at centromeres being carried out by the mitosis-specific kinase, haspin. Furthermore, Bub1 phosphorylation of histone H2A recruits shugoshin, a centromeric CPC adapter. Thus, these two histone marks in combination define the inner centromere.
One Theory to Rule Them All

The Grand Design
by Stephen Hawking and Leonard Mlodinow

Bantam, New York, 2010. $28, C$33. 207 pp. ISBN 9780553805376. eBook, $28. ISBN 978055390707.
Authors: Silk Joseph
Published: October 2010

Drawing on Hawking's research and on recent astronomical observations and theoretical developments, the authors offer nonspecialists an account of the laws of physics that denies the existence of a grand unified theory.
Thaumarchaeal Ammonia Oxidation in an Acidic Forest Peat Soil Is Not Influenced by Ammonium Amendment
Authors: Stopnišek Nejc , Gubry-Rangin Cécile , Höfferle Špela , Nicol Graeme W. , Mandič-Mulec Ines , Prosser James I.
Published: October 2010

Both bacteria and thaumarchaea contribute to ammonia oxidation, the first step in nitrification. The abundance of putative ammonia oxidizers is estimated by quantification of the functional gene
amoA
, which encodes ammonia monooxygenase subunit A. In soil, thaumarchaeal
amoA
genes often outnumber the equivalent bacterial genes. Ecophysiological studies indicate that thaumarchaeal ammonia oxidizers may have a selective advantage at low ammonia concentrations, with potential adaptation to soils in which mineralization is the major source of ammonia. To test this hypothesis, thaumarchaeal and bacterial ammonia oxidizers were investigated during nitrification in microcosms containing an organic, acidic forest peat soil (pH 4.1) with a low ammonium concentration but high potential for ammonia release during mineralization. Net nitrification rates were high but were not influenced by addition of ammonium. Bacterial
amoA
genes could not be detected, presumably because of low abundance of bacterial ammonia oxidizers. Phylogenetic analysis of thaumarchaeal 16S rRNA gene sequences indicated that dominant populations belonged to group 1.1c, 1.3, and “deep peat” lineages, while known
amo
-containing lineages (groups 1.1a and 1.1b) comprised only a small proportion of the total community. Growth of thaumarchaeal ammonia oxidizers was indicated by increased abundance of
amoA
genes during nitrification but was unaffected by addition of ammonium. Similarly, denaturing gradient gel electrophoresis analysis of
amoA
gene transcripts demonstrated small temporal changes in thaumarchaeal ammonia oxidizer communities but no effect of ammonium amendment. Thaumarchaea therefore appeared to dominate ammonia oxidation in this soil and oxidized ammonia arising from mineralization of organic matter rather than added inorganic nitrogen.
Evaluation of Virulence Factor Profiling in the Characterization of Veterinary
Escherichia coli
Isolates
Authors: David Donna E. , Lynne Aaron M. , Han Jing , Foley Steven L.
Published: October 2010

Escherichia coli
has been used as an indicator organism for fecal contamination of water and other environments and is often a commensal organism in healthy animals, yet a number of strains can cause disease in young or immunocompromised animals. In this study, 281
E. coli
isolates from bovine, porcine, chicken, canine, equine, feline, and other veterinary sources were analyzed by BOXA1R PCR and by virulence factor profiling of 35 factors to determine whether they had utility in identifying the animal source of the isolates. The results of BOXA1R PCR analysis demonstrated a high degree of diversity; less than half of the isolates fell into one of 27 clusters with at least three isolates (based on 90% similarity). Nearly 60% of these clusters contained isolates from more than one animal source. Conversely, the results of virulence factor profiling demonstrated clustering by animal source. Three clusters, named Bovine, Chicken, and Porcine, based on discriminant components analysis, were represented by 90% or more of the respective isolates. A fourth group, termed Companion, was the most diverse, containing at least 84% of isolates from canine, feline, equine, and other animal sources. Based on these results, it appears that virulence factor profiling may have utility, helping identify the likely animal host species sources of certain
E. coli
isolates.
Exploring the Low-Pressure Growth Limit: Evolution of
Bacillus subtilis
in the Laboratory to Enhanced Growth at 5 Kilopascals
Authors: Nicholson Wayne L. , Fajardo-Cavazos Patricia , Fedenko Jeffrey , Ortíz-Lugo José L. , Rivas-Castillo Andrea , Waters Samantha M. , Schuerger Andrew C.
Published: October 2010

Growth of
Bacillus subtilis
cells, normally adapted at Earth-normal atmospheric pressure (∼101.3 kPa), was progressively inhibited by lowering of pressure in liquid LB medium until growth essentially ceased at 2.5 kPa. Growth inhibition was immediately reversible upon return to 101.3 kPa, albeit at a slower rate. A population of
B. subtilis
cells was cultivated at the near-inhibitory pressure of 5 kPa for 1,000 generations, where a stepwise increase in growth was observed, as measured by the turbidity of 24-h cultures. An isolate from the 1,000-generation population was obtained that showed an increase in fitness at 5 kPa when compared to the ancestral strain or a strain obtained from a parallel population that evolved for 1,000 generations at 101.3 kPa. The results from this preliminary study have implications for understanding the ability of terrestrial microbes to grow in low-pressure environments such as Mars.
Production of Hydrogen Gas from Light and the Inorganic Electron Donor Thiosulfate by
Rhodopseudomonas palustris
Authors: Huang Jean J. , Heiniger Erin K. , McKinlay James B. , Harwood Caroline S.
Published: October 2010

A challenge for photobiological production of hydrogen gas (H
2
) as a potential biofuel is to find suitable electron-donating feedstocks. Here, we examined the inorganic compound thiosulfate as a possible electron donor for nitrogenase-catalyzed H
2
production by the purple nonsulfur phototrophic bacterium (PNSB)
Rhodopseudomonas palustris
. Thiosulfate is an intermediate of microbial sulfur metabolism in nature and is also generated in industrial processes. We found that
R. palustris
grew photoautotrophically with thiosulfate and bicarbonate and produced H
2
when nitrogen gas was the sole nitrogen source (nitrogen-fixing conditions). In addition, illuminated nongrowing
R. palustris
cells converted about 80% of available electrons from thiosulfate to H
2
. H
2
production with acetate and succinate as electron donors was less efficient (40 to 60%), partly because nongrowing cells excreted the intermediary metabolite α-ketoglutarate into the culture medium. The
fixABCX
operon (RPA4602 to RPA4605) encoding a predicted electron-transfer complex is necessary for growth using thiosulfate under nitrogen-fixing conditions and may serve as a point of engineering to control rates of H
2
production. The possibility to use thiosulfate expands the range of electron-donating compounds for H
2
production by PNSBs beyond biomass-based electron donors.
Kinetic Analysis of Strains of Lactic Acid Bacteria and Acetic Acid Bacteria in Cocoa Pulp Simulation Media toward Development of a Starter Culture for Cocoa Bean Fermentation
Authors: Lefeber Timothy , Janssens Maarten , Camu Nicholas , De Vuyst Luc
Published: October 2010

The composition of cocoa pulp simulation media (PSM) was optimized with species-specific strains of lactic acid bacteria (PSM-LAB) and acetic acid bacteria (PSM-AAB). Also, laboratory fermentations were carried out in PSM to investigate growth and metabolite production of strains of
Lactobacillus plantarum
and
Lactobacillus fermentum
and of
Acetobacter pasteurianus
isolated from Ghanaian cocoa bean heap fermentations, in view of the development of a defined starter culture. In a first step, a selection of strains was made out of a pool of strains of these LAB and AAB species, obtained from previous studies, based on their fermentation kinetics in PSM. Also, various concentrations of citric acid in the presence of glucose and/or fructose (PSM-LAB) and of lactic acid in the presence of ethanol (PSM-AAB) were tested. These data could explain the competitiveness of particular cocoa-specific strains, namely,
L. plantarum
80 (homolactic and acid tolerant),
L. fermentum
222 (heterolactic, citric acid fermenting, mannitol producing, and less acid tolerant), and
A. pasteurianus
386B (ethanol and lactic acid oxidizing, acetic acid overoxidizing, acid tolerant, and moderately heat tolerant), during the natural cocoa bean fermentation process. For instance, it turned out that the capacity to use citric acid, which was exhibited by
L. fermentum
222, is of the utmost importance. Also, the formation of mannitol was dependent not only on the LAB strain but also on environmental conditions. A mixture of
L. plantarum
80,
L. fermentum
222, and
A. pasteurianus
386B can now be considered a mixed-strain starter culture for better controlled and more reliable cocoa bean fermentation processes.
Changes in the Structure and Function of Microbial Communities in Drinking Water Treatment Bioreactors upon Addition of Phosphorus
Authors: Li Xu , Upadhyaya Giridhar , Yuen Wangki , Brown Jess , Morgenroth Eberhard , Raskin Lutgarde
Published: October 2010

Phosphorus was added as a nutrient to bench-scale and pilot-scale biologically active carbon (BAC) reactors operated for perchlorate and nitrate removal from contaminated groundwater. The two bioreactors responded similarly to phosphorus addition in terms of microbial community function (i.e., reactor performance), while drastically different responses in microbial community structure were detected. Improvement in reactor performance with respect to perchlorate and nitrate removal started within a few days after phosphorus addition for both reactors. Microbial community structures were evaluated using molecular techniques targeting 16S rRNA genes. Clone library results showed that the relative abundance of perchlorate-reducing bacteria (PRB)
Dechloromonas
and
Azospira
in the bench-scale reactor increased from 15.2% and 0.6% to 54.2% and 11.7% after phosphorus addition, respectively. Real-time quantitative PCR (qPCR) experiments revealed that these increases started within a few days after phosphorus addition. In contrast, after phosphorus addition, the relative abundance of
Dechloromonas
in the pilot-scale reactor decreased from 7.1 to 0.6%, while
Zoogloea
increased from 17.9 to 52.0%. The results of this study demonstrated that similar operating conditions for bench-scale and pilot-scale reactors resulted in similar contaminant removal performances, despite dramatically different responses from microbial communities. These findings suggest that it is important to evaluate the microbial community compositions inside bioreactors used for drinking water treatment, as they determine the microbial composition in the effluent and impact downstream treatment requirements for drinking water production. This information could be particularly relevant to drinking water safety, if pathogens or disinfectant-resistant bacteria are detected in the bioreactors.
Genome Analysis of Deep-Sea Thermophilic Phage D6E
Authors: Wang Yiqian , Zhang Xiaobo
Published: October 2010

In deep-sea hydrothermsal vent communities, viruses play very important roles. However vent thermophilic bacteriophages remain largely unexplored. In this investigation, a novel vent
Geobacillus
bacteriophage, D6E, was characterized. Based on comparative genomics and proteomics analyses, the results showed an extensive mosaicism of D6E genome with other mesophilc or thermophilic phages.
Effect of
Salmonella
Vaccination of Breeder Chickens on Contamination of Broiler Chicken Carcasses in Integrated Poultry Operations
Authors: Dórea Fernanda C. , Cole Dana J. , Hofacre Charles , Zamperini Katherine , Mathis Demetrius , Doyle Michael P. , Lee Margie D. , Maurer John J.
Published: October 2010

While measures to control carcass contamination with
Salmonella
at the processing plant have been implemented with some success, on-farm interventions that reduce
Salmonella
prevalence in meat birds entering the processing plant have not translated well on a commercial scale. We determined the impact of
Salmonella
vaccination on commercial poultry operations by monitoring four vaccinated and four nonvaccinated breeder (parental) chicken flocks and comparing
Salmonella
prevalences in these flocks and their broiler, meat bird progeny. For one poultry company, their young breeders were vaccinated by using a live-attenuated
Salmonella enterica
serovar Typhimurium vaccine (Megan VAC-1) followed by a killed
Salmonella
bacterin consisting of
S. enterica
serovar Berta and
S. enterica
serovar Kentucky. The other participating poultry company did not vaccinate their breeders or broilers. The analysis revealed that vaccinated hens had a lower prevalence of
Salmonella
in the ceca (38.3% versus 64.2%;
P
< 0.001) and the reproductive tracts (14.22% versus 51.7%;
P
< 0.001). We also observed a lower
Salmonella
prevalence in broiler chicks (18.1% versus 33.5%;
P
< 0.001), acquired from vaccinated breeders, when placed at the broiler farms contracted with the poultry company. Broiler chicken farms populated with chicks from vaccinated breeders also tended to have fewer environmental samples containing
Salmonella
(14.4% versus 30.1%;
P
< 0.001). There was a lower
Salmonella
prevalence in broilers entering the processing plants (23.4% versus 33.5%;
P
< 0.001) for the poultry company that utilized this
Salmonella
vaccination program for its breeders. Investigation of other company-associated factors did not indicate that the difference between companies could be attributed to measures other than the vaccination program.
High-Cell-Density Cyclic Fed-Batch Fermentation of a Poly(3-Hydroxybutyrate)-Accumulating Thermophile,
Chelatococcus
sp. Strain MW10
Authors: Ibrahim Mohammad H. A. , Steinbüchel Alexander
Published: October 2010

Different fermentation strategies were employed for the cultivation of a new poly(3-hydroxybutyrate)-accumulating thermophilic bacterium,
Chelatococcus
sp. strain MW10, with the aim of achieving high-cell-density (HCD) growth and high poly(3-hydroxybutyrate) [poly(3HB)] productivity. Enhanced cultivation was achieved by a cyclic fed-batch fermentation (CFBF) technique (42-liter scale). Maximal poly(3HB) productivity was obtained during the second cycle [16.8 ± 4.2 g poly(3HB)/liter]. At the end of CFBF (265 h), an HCD of up to 115.0 ± 4.3 g cell dry weight/liter was achieved.
Combined Effects of Long-Living Chemical Species during Microbial Inactivation Using Atmospheric Plasma-Treated Water
Authors: Naïtali Murielle , Kamgang-Youbi Georges , Herry Jean-Marie , Bellon-Fontaine Marie-Noëlle , Brisset Jean-Louis
Published: October 2010

Electrical discharges in humid air at atmospheric pressure (nonthermal quenched plasma) generate long-lived chemical species in water that are efficient for microbial decontamination. The major role of nitrites was evidenced together with a synergistic effect of nitrates and H
2
O
2
and matching acidification. Other possible active compounds are considered, e.g., peroxynitrous acid.
Identification ofMET10-932and Characterization as an Allele Reducing Hydrogen Sulfide Formation in Wine Strains ofSaccharomyces cerevisiae
Authors: Linderholm Angela , Dietzel Kevin , Hirst Marissa , Bisson Linda F.
Published: October 2010

A vineyard isolate of the yeastSaccharomyces cerevisiae, UCD932, was identified as a strain producing little or no detectable hydrogen sulfide during wine fermentation. Genetic analysis revealed that this trait segregated as a single genetic determinant. The gene also conferred a white colony phenotype on BiGGY agar (bismuth-glucose-glycine-yeast agar), which is thought to indicate low basal levels of sulfite reductase activity. However, this isolate does not display a requirement for S-containing amino acids, indicating that the sulfate reduction pathway is fully operational. Genetic crosses against known mutations conferring white colony color on BiGGY agar identified the gene leading to reduced H2S formation as an allele ofMET10(MET10-932), which encodes a catalytic subunit of sulfite reductase. Sequence analysis ofMET10-932revealed several corresponding amino acid differences in relation to laboratory strain S288C. Allele differences for other genes of the sulfate reduction pathway were also detected in UCD932. TheMET10allele of UCD932 was found to be unique in comparison to the sequences of several other vineyard isolates with differing levels of production of H2S. Replacing theMET10allele of high-H2S-producing strains withMET10-932prevented H2S formation by those strains. A single mutative change, corresponding to T662K, inMET10-932resulted in a loss of H2S production. The role of site 662 in sulfide reduction was further analyzed by changing the encoded amino acid at this position. A change back to threonine or to the conservative serine fully restored the H2S formation conferred by this allele. In addition to T662K, arginine, tryptophan, and glutamic acid substitutions similarly reduced sulfide formation.
Functional Gene Analysis Suggests Different Acetogen Populations in the Bovine Rumen and Tammar Wallaby Forestomach
Authors: Gagen Emma J. , Denman Stuart E. , Padmanabha Jagadish , Zadbuke Someshwar , Al Jassim Rafat , Morrison Mark , McSweeney Christopher S.
Published: October 2010

Reductive acetogenesis via the acetyl coenzyme A (acetyl-CoA) pathway is an alternative hydrogen sink to methanogenesis in the rumen. Functional gene-based analysis is the ideal approach for investigating organisms capable of this metabolism (acetogens). However, existing tools targeting the formyltetrahydrofolate synthetase gene (
fhs
) are compromised by lack of specificity due to the involvement of formyltetrahydrofolate synthetase (FTHFS) in other pathways. Acetyl-CoA synthase (ACS) is unique to the acetyl-CoA pathway and, in the present study, acetyl-CoA synthase genes (
acsB
) were recovered from a range of acetogens to facilitate the design of
acsB
-specific PCR primers.
fhs
and
acsB
libraries were used to examine acetogen diversity in the bovine rumen and forestomach of the tammar wallaby (
Macropus eugenii
), a native Australian marsupial demonstrating foregut fermentation analogous to rumen fermentation but resulting in lower methane emissions. Novel, deduced amino acid sequences of
acsB
and
fhs
affiliated with the
Lachnospiraceae
in both ecosystems and the
Ruminococcaeae/Blautia
group in the rumen. FTHFS sequences that probably originated from nonacetogens were identified by low “homoacetogen similarity” scores based on analysis of FTHFS residues, and comprised a large proportion of FTHFS sequences from the tammar wallaby forestomach. A diversity of FTHFS and ACS sequences in both ecosystems clustered between the
Lachnospiraceae
and
Clostridiaceae
acetogens but without close sequences from cultured isolates. These sequences probably originated from novel acetogens. The community structures of the
acsB
and
fhs
libraries from the rumen and the tammar wallaby forestomach were different (LIBSHUFF,
P
< 0.001), and these differences may have significance for overall hydrogenotrophy in both ecosystems.
Glutaredoxins Grx4 and Grx3 of
Saccharomyces cerevisiae
Play a Role in Actin Dynamics through Their Trx Domains, Which Contributes to Oxidative Stress Resistance
Authors: Pujol-Carrion Nuria , de la Torre-Ruiz Maria Angeles
Published: October 2010

Grx3 and Grx4 are two monothiol glutaredoxins of
Saccharomyces cerevisiae
that have previously been characterized as regulators of Aft1 localization and therefore of iron homeostasis. In this study, we present data showing that both Grx3 and Grx4 have new roles in actin cytoskeleton remodeling and in cellular defenses against oxidative stress caused by reactive oxygen species (ROS) accumulation. The Grx4 protein plays a unique role in the maintenance of actin cable integrity, which is independent of its role in the transcriptional regulation of Aft1. Grx3 plays an additive and redundant role, in combination with Grx4, in the organization of the actin cytoskeleton, both under normal conditions and in response to external oxidative stress. Each Grx3 and Grx4 protein contains a thioredoxin domain sequence (Trx), followed by a glutaredoxin domain (Grx). We performed functional analyses of each of the two domains and characterized different functions for them. Each of the two Grx domains plays a role in ROS detoxification and cell viability. However, the Trx domain of each Grx4 and Grx3 protein acts independently of its respective Grx domain in a novel function that involves the polarization of the actin cytoskeleton, which also determines cell resistance against oxidative conditions. Finally, we present experimental evidence demonstrating that Grx4 behaves as an antioxidant protein increasing cell survival under conditions of oxidative stress.
Limitations in Xylose-FermentingSaccharomyces cerevisiae, Made Evident through Comprehensive Metabolite Profiling and Thermodynamic Analysis
Authors: Klimacek Mario , Krahulec Stefan , Sauer Uwe , Nidetzky Bernd
Published: October 2010

Little is known about how the general lack of efficiency with which recombinantSaccharomyces cerevisiaestrains utilize xylose affects the yeast metabolome. Quantitative metabolomics was therefore performed for two xylose-fermentingS. cerevisiaestrains, BP000 and BP10001, both engineered to produce xylose reductase (XR), NAD+-dependent xylitol dehydrogenase and xylulose kinase, and the corresponding wild-type strain CEN.PK 113-7D, which is not able to metabolize xylose. Contrary to BP000 expressing an NADPH-preferring XR, BP10001 expresses an NADH-preferring XR. An updated protocol of liquid chromatography/tandem mass spectrometry that was validated by applying internal13C-labeled metabolite standards was used to quantitatively determine intracellular pools of metabolites from the central carbon, energy, and redox metabolism and of eight amino acids. Metabolomic responses to different substrates, glucose (growth) or xylose (no growth), were analyzed for each strain. In BP000 and BP10001, flux through glycolysis was similarly reduced (∼27-fold) when xylose instead of glucose was metabolized. As a consequence, (i) most glycolytic metabolites were dramatically (≤120-fold) diluted and (ii) energy and anabolic reduction charges were affected due to decreased ATP/AMP ratios (3- to 4-fold) and reduced NADP+levels (∼3-fold), respectively. Contrary to that in BP000, the catabolic reduction charge was not altered in BP10001. This was due mainly to different utilization of NADH by XRs in BP000 (44%) and BP10001 (97%). Thermodynamic analysis complemented by enzyme kinetic considerations suggested that activities of pentose phosphate pathway enzymes and the pool of fructose-6-phosphate are potential factors limiting xylose utilization. Coenzyme and ATP pools did not rate limit flux through xylose pathway enzymes.