bluuebunny/crossref_metadata_2025 huggingface dataset:
AMERICAN NEWSMAGAZINE COVERAGE OF THE PERSIAN GULF WAR: THE PARALLELS OF WORLD WAR II AND VIETNAM
Authors: King Erika G. , Wells Robert A.
Published: August 2010

This study presents the results of a content analysis of the amount, content, and tone of references to the historical parallels of World War II and the Vietnam War in three American newsmagazines' coverage of the Persian Gulf War. The hypothesis that the newsmagazines will be more likely to present the historical parallels of the Gulf War as analogous to World War II than the opposing frame of the Vietnam War is supported by the data. Thus the three newsmagazines were mostly supportive of the historical interpretation of the conflict presented by the Bush administration. A second hypothesis that a “rally‐‘round‐the‐flag” effect will occur as the military build‐up phase of Desert Shield is replaced by the military engagement phase of Desert Storm is not consistently supported by the data. There is also modest variation between the newsmagazines in the degree to which the World War II analogy is accepted and the Vietnam War analogy is rejected.
THE PERSISTENCE OF SEX SEGREGATED EDUCATION IN THE SOUTH
Authors: Mezey Susan Gluck
Published: August 2010

This study focuses on the convergence of three strains of southern beliefs: views toward women, views toward education, and views toward the military. These beliefs coalesced in the legal battle over the admission of women to the all‐male Virginia Military Institute (VMI). Following the example of those who challenged single sex admissions policies in southern public colleges over the last two decades, women contested the exclusionary admissions policy at VMI. Although the earlier challenges had not always succeeded, by 1990 it seemed likely that law and custom had changed sufufficiently that the federal courts would rule against VMI.

After exploring the “southern” view of women, followed by a brief history of women's educational opportunities and the reluctance of the federal courts to depart from the separate but equal doctrine in public higher education, this study will examine the federal court rulings that sanctioned the continuation of sex‐segregated education at VMI.
THE ELECTORAL CONSEQUENCES OF COALITION BEHAVIOR
Authors: Posey Kevin H.
Published: August 2010

This paper is an examination of the possibility that electoral punishment for a party's choice of coalitions does exist. Previous writings have inferred that this is not the case. It has been an assumption that voters forget their parties' transgressions. This frees the party leadership to negotiate in the coalition bargaining process without regard to the previous election's outcome. However, while punishment may not take place in all cases, it does appear to occur in some. According to the election results taken from elections following the postwar “Grand Coalitions,” it would appear that the leaders of small, lefrist parties have something to worry about. They are not free to bargain without paying heed to their supporters. it is therefore unlikely that they are unaware of their constrained position, given the party leadership's understandable desire to maintain a respectable presence in the next election cycle.
UNITED STATES SUPREME COURT JUSTICES AND BIRTH ORDER
Authors: Somit Albert , Peterson Steven A. , Arwine Alan
Published: August 2010

Birth order has been hypothesized to affect (a) accession into elite political positions and (b) better caliber performance once in office. This research note reports data on all members of the United States Supreme Court in terms of their birth order and performance once in office. It does appear that first borns are more apt to serve on the Court, although this may be an artifact of the advantages in terms of education for first borns in the American historical context. However, there is no sound evidence from the data reported upon here which would indicate that first born justices are more able than their later born peers. Thus, some doubt is raised about the power claimed for birth order on political achievement.
GUT FEELINGS AND POLICY DECISIONS
Authors: Sellers Martin P.
Published: August 2010

Gut feelings have long played a role in decision making. Ask any policy maker about the utility and significance of personal sensitivities and gut feelings in his decisions and he will admit that to some degree, though difficult to measure, decision influences like gut feelings play a significant role in policy making. Theorists who have studied interpretive decision making such as Alfred Schultz, Chris Argyris, Peter Berger, Thomas Luckmann, Larry Kirkhart, David Silverman, Michael Harmon and others suggest that much more goes into decisions in the policy making process than the observable, overt, measurable, rational elements that rational measurement devices such as cost‐benefit analysis can evaluate. This paper will attempt to show that the interpretive approach is a well‐grounded model to use in decision making and policy analysis and will also develop a model for decision makers to use in evaluating the influences that affect their decisions and ultimately the policy making process.
THE TRANSFER OF POLITICAL FUNCTIONS FROM THE NATIONAL PARTY COMMITTEES TO THE WHITE HOUSE: FROM EISENHOWER TO NIXON
Authors: Thompson Carolyn R. , Brown Roger G.
Published: August 2010

During the New Deal and succeeding administrations national power and authority became increasingly more centralized in the White House and Executive Office of the President. As this institutionalized presidency emerged, increasing numbers of political functions were centralized in the expanding office of the president. This paper examines the changing structural relationship between the White House and the national party with particular emphasis on the distribution of patronage appointments and staffing the executive branch. The period of analysis begins with the Eisenhower administration and concludes with the Nixon presidency. The authors note that although subsequent administrations may demonstrate the unintended effects of this concentration of authority, it is unlikely that it will be willfully reversed.
DOMESTIC STRUCTURE AND COLLECTIVE SECURITY
Authors: Spiezio K. Edward
Published: August 2010

Neorealism and neoliberal institutionalism are unable to account for the variability states exhibit when it comes to the subject of collective security systems because neither approach controls for the impact domestic politics can have on a state's ability to participate in this type of multilateral institution. A domestic structures perspective can address this shortcoming by highlighting the influence domestic political norms and institutions can exert in regard to a state's ability to make international security commitments and its ability to contribute to multilateral enforcement efforts. This essay provides evidence in support of these claims and outlines a research agenda for investigating the consequences domestic politics may hold for the viability and efficacy of collective security institutions.
BILL CLINTON AS WARREN HARDING: THE POST‐WAR PRESIDENT AS A PROBLEM IN AMERICAN POLITICAL DEVELOPMENT
Authors: Langston Thomas S.
Published: August 2010

The post‐Cold War presidency of Bill Clinton is compared to that of Warren Harding and other post‐war presidents. Somefam iliarfeatures of contemporary presidential politics are seen in this light as the latest manifestations of a recurring pattern in presidential politics. The transition from war to peace is marked today, as it has been in the past, by a flight from liberalism, factionalism within the president's party, and the chief executive's resilience against scandal.
AFFIRMATIVE ACTION AND LOCAL GOVERNMENTS: THE VIEWS OF CITY COUNCIL AND SCHOOL BOARD MEMBERS
Authors: Schumaker Paul , Kelly Marisa
Published: August 2010

This paper explores the attitudes regarding affirmative action of 112 members of city councils and school boards in twelve American cities. In‐depth interviews with these officials reveal widespread support for affirmative action policies generally and for more moderate approaches to affirmative action in particular. Our analysis suggests that more aggressive forms of affirmative action—establishing quotas in hiring and setasides when awarding contracts—are especially opposed by conservatives and those in high prestige occupations and by school board members who are wary of giving priority to social justice over securing highly qualified teachers. Our analysis also suggests that extensive support for more moderate forms of affirmative action—giving preference to qualified minority candidates, requiring minority participation by companies that do business with the city, training and mentoring persons from disadvantaged groups, and taking extraordinary steps to recruit blacks and women into public offices—is rooted in concerns about morality and justice.
RELUCTANT SUFFRAGIST, UNWITTING FEMINIST: THE AMBIVALENT POLITICAL VOICE OF CORRA HARRIS
Authors: Badura Catherine
Published: August 2010

This research explores some of the political ideas of Georgia novelist Corra White Harris (1869‐ 1935). Harris's ambivalent political positions are juxtaposed with two of her Georgia contemporaries–suffragist Rebecca Latimer Felton and anti‐suffragist Mildred Lewis Rutherford. A central premise of the analysis is that in her political uncertainly, though not in her particular opinions, Harris better represented women who never took a stand on suffrage or feminism than do political activists such as Felton and Rutherford who were more confident in their positions.
A TALE OF TWO DECADES: SOUTHERN HOUSE ELECTIONS IN THE 1980s AND 1990s
Authors: Beachler Donald W.
Published: August 2010

In the 1980s Republicans were unable to capture a majority of southern seats in the US House of Representatives. In the 1990s the GOP gained seats in the South in three consecutive elections. After the 1994 election, Republicans held a majority of southern House seats for the first time since Reconstruction. This note argues that southern House elections were nationalized in the 1990s as districts that voted Republican in presidential elections were far more likely to elect a Republican representative than in the preceding decade.
A Note on the Action of Usnic Acid on Anaesthetized Cats.
Authors: SÖDERBERG. ULF
Published: August 2010

1. Experiments have been performed with usnic acid on eats anaesthetized with nembutal or, in a few cases, with chloralose.

2. 10 mg sodium usnate/kg body weight caused a prompt and heavy rise in oxygen consumption accompanied by a pronounced increase in rate and amplitude of respiration and by a gradual rise in body temperature, lasting for about 5 hours and then dowly falling.

3. Larger doses are as a rule lethal.

4. Lethal doses cause an intense rigor mortis. This effect is opposite to the effect of vulpinic acid but similar to the Well known action of the dinitrophenols.

5. In normal anaesthetized cats there is a steep rise in arterial blood sugar to a level of 300–400 mg% lasting for about the same time as the increased respiratory volume. In fasted cats the rise is much slower and somewhat smaller.

6. It is concluded that the major part of the rise in arterial blood sugar is due to an increased breakdown of glycogen to glucose, but there may be increased gluconeogenesis.

7. The actions of usnic acid in the cat are, in the whole, very similar to those of the dinitrophenols.
Calcium channels in chromaffin cells: focus on L and T types
Authors: Marcantoni A. , Carabelli V. , Comunanza V. , Hoddah H. , Carbone E.
Published: August 2010

Voltage‐gated Ca2+channels (Cav) are highly expressed in the adrenal chromaffin cells of mammalian species. Besides shaping action potential waveforms, they are directly involved in the excitation–secretion coupling underlying catecholamine release and, possibly, control other Ca2+‐dependent events that originate near the membrane. These functions are shared by a number of Cav channel types (L, N, P/Q, R and T) which have different structure–function characteristics and whose degree of expression changes remarkably among mammalian species. Understanding precisely the functioning of each voltage‐gated Ca2+channels is a crucial task that helps clarifying the Ca2+‐dependent mechanisms controlling exocytosis during physiological and pathological conditions. In this paper, we focus on classical and new roles that L‐ and T‐type channels play in the control of chromaffin cell excitability and neurotransmitter release. Interestingly, L‐type channels are shown to be implicated in the spontaneous autorhythmicity of chromaffin cells, while T‐type channels, which are absent in adult chromaffin cells, are coupled with secretion and can be recruited following long‐term β‐adrenergic stimulation or chronic hypoxia. This suggests that like other cells, adrenal chromaffin cells undergo effective remodelling of membrane ion channels and cell functioning during prolonged stress conditions.
Nominal Classification
Authors: Seifart Frank
Published: August 2010

Many languages have morphosyntactic systems that impose a classification on their nominal lexicon. The nature of these systems varies widely, ranging from large systems of lexico‐syntactic numeral classifiers, as known from East and South East Asian languages, to highly grammaticalized gender agreement systems of, e.g. European languages (seeAikhenvald 2000for a comprehensive overview). These systems are also often internally complex, heterogeneous, and descriptively challenging. The morphology, syntax, and semantics of nominal classification bear ample material for interesting research questions in, e.g. typology and historical linguistics. This article reviews some basic features of nominal classification and discusses a number of selected issues that are particularly relevant for ongoing discussions and future research: How can nominal classification systems be typologized according to morphosyntactic criteria (Section 2)? What are the semantic principles of nominal classification and how do they relate to culture and cognition (Section 3)? How does nominal classification diachronically develop and diffuse across languages (Section 4)?
Correlates of Language Change in Hunter‐Gatherer and Other ‘Small’ Languages
Authors: Bowern Claire
Published: August 2010

I review linguistic and interdisciplinary research on the non‐linguistic correlates of language change, particularly as they apply to small populations, highly mobile groups, and hunter‐gatherers. I summarize the areas which have been argued to display differences between hunter‐gatherers and agriculturalists, small and large populations, and sedentary and non‐sedentary ones, although finding that none of this work is conclusive and much is contradictory. Hunter‐gatherer languages in particular have played a prominent role in the development of theories of language change in addition to the comparative method and family trees, but for the wrong reasons, since the comparative method is powerful for diagnosing relationships even in the case of heavy borrowing where tree models are not useful. The field is in great need of systematization, and of incorporating current knowledge about variation and the spread of change with reconstruction over a longer time span.
THE INFLUENCE OF PRACTITIONER AND PRACTICE CHARACTERISTICS ON SERVICE ACTIVITY LEVELS IN A NEW ZEALAND GENERAL PRACTICE SAMPLE
Authors: Davis Peter B. , Yee Roy Lay
Published: August 2010

The impact of practitioner and practice‐related characteristics on service activity levels in general practice is assessed. It is hypothesized that while initial medical contact is largely patient‐initiated and hence influenced by broader social factors, the subsequent provision of services within the medical system is more likely to be determined by organisational and professional factors.

The data are drawn from a one per cent sample of all weekday general practice office encounters in the Hamilton Health District recorded over a twelve‐month period from February 1979.

The average encounter involved three services: typically a history or examination, a prescription and a request for follow‐up. Activity levels were measured as the number of services received from the general practitioner by patients in the course of the medical encounter.

The broad social characteristics of patients had little impact on activity level. Descriptors of patient health condition, and related attributes such as age and gender, were only moderately predictive of the number of services received. Practitioner and practice‐related characteristics seemed to exert little influence, even after controlling for case mix.

The strongest predictor of the number of services provided was the identity of the patient's doctor. Of the 30 per cent of variation in total service use explained by the model, half was accounted for by practitioner identity.
The Novel Antidepressant Agomelatine Normalizes Hippocampal Neuronal Activity and Promotes Neurogenesis in Chronically Stressed Rats
Authors: Dagytė Girstautė , Trentani Andrea , Postema Folkert , Luiten Paul G. , Den Boer Johan A. , Gabriel Cecilia , Mocaër Elisabeth , Meerlo Peter , Van der Zee Eddy A.
Published: August 2010

Agomelatine is a novel antidepressant which acts as a melatonergic (MT1/MT2) receptor agonist and serotonergic (5‐HT2C) receptor antagonist. The antidepressant properties of agomelatine have been demonstrated in animal models as well as in clinical studies. Several preclinical studies reported agomelatine‐induced effects on brain plasticity, mainly under basal conditions in healthy animals. Yet, it is important to unravel agomelatine‐mediated changes in the brain affected by psychopathology or exposed to conditions that might predispose to mood disorders. Since stress is implicated in the etiology of depression, it is valid to investigate antidepressant‐induced effects in animals subjected to chronic stress. In this context, we sought to determine changes in the brain after agomelatine treatment in chronically stressed rats. Adult male rats were subjected to footshock stress and agomelatine treatment for 21 consecutive days. Rats exposed to footshock showed a robust increase in adrenocorticotropic hormone (ACTH) and corticosterone. Chronic agomelatine treatment did not markedly influence this HPA‐axis response. Whereas chronic exposure to daily footshock stress reduced c‐Fos expression in the hippocampal dentate gyrus, agomelatine treatment reversed this effect and normalized neuronal activity to basal levels. Moreover, chronic agomelatine administration was associated with enhanced hippocampal cell proliferation and survival in stressed but not in control rats. Furthermore, agomelatine reversed the stress‐induced decrease in doublecortin expression in the dentate gyrus. Taken together, these data show a beneficial action of agomelatine in the stress‐compromised brain, where it restores stress‐affected hippocampal neuronal activity and promotes adult hippocampal neurogenesis.
Critical role of Nitric Oxide on Nicotine‐Induced Hyperactivation of Dopaminergic Nigrostriatal System: Electrophysiological and Neurochemical evidence in Rats
Authors: Di Matteo Vincenzo , Pierucci Massimo , Benigno Arcangelo , Esposito Ennio , Crescimanno Giuseppe , Di Giovanni Giuseppe
Published: August 2010

Nicotine, the main psychoactive ingredient in tobacco, stimulates dopamine (DA) function, increasing DA neuronal activity and DA release. DA is involved in both motor control and in the rewarding and reinforcing effects of nicotine; however, the complete understanding of its molecular mechanisms is yet to be attained. Substantial evidence indicates that the reinforcing properties of drugs of abuse, including nicotine, can be affected by the nitric oxide (NO) system, which may act by modulating central dopaminergic function. In this study, using single cell recordingsin vivocoupled with microiontophoresis and microdialysis in freely moving animals, the role of NO signaling on the hyperactivation elicited by nicotine of the nigrostriatal system was investigated in rats. Nicotine induced a dose‐dependent increase of the firing activity of the substantia nigra pars compacta (SNc) DA neurons and DA and 3,4‐dihydroxyphenylacetic acid (DOPAC) release in the striatum. Pharmacological manipulation of the NO system did not produce any change under basal condition in terms of neuronal discharge and DA release. In contrast, pretreatments with two NO synthase (NOS) inhibitors, N‐ω‐nitro‐l‐arginine methyl ester (l‐NAME) and 7‐nitroindazole (7‐NI) were both capable of blocking the nicotine‐induced increase of SNc DA neuron activity and DA striatal levels. The effects of nicotine inl‐NAME and 7‐NI‐pretreated rats were partially restored when rats were pretreated with the NO donor molsidomine. These results further support the evidence of an important role played by NO on modulation of dopaminergic function and drug addiction, thus revealing new pharmacological possibilities in the treatment of nicotine dependence and other DA dysfunctions.
Investigation of the Thermal Capacity of Railroad Wheels Using COBRA Brake Shoes
Authors: Weaver G. R. , Archibald P. A. , Brenneman E. B. , Cabble G. M.
Published: August 2010

An objective evaluation of the thermal capacity of 36 in. CR wheels braked with COBRA brake shoes is presented and related to that of wheels braked with cast metal brake shoes. The wheel tread conditions, hardness and macrostructure of the rim, and residual stress patterns, which developed from high speed dynamometer braking-were investigated through three progressive test series. The results indicate that the thermal capacity of wheels braked with COBRA brake shoes far exceeds limits previously established for cast metal shoes.
Evaluation of Dynamic Factors for Spur and Helical Gears
Authors: Seireg A. , Houser D. R.
Published: August 2010

This paper deals with the development of a generalized dynamic factor for spur and helical gears operating away from system resonances. The experimental results of the tests reported in the previous paper [1] are used in conjunction with mathematical simulation of the gear system and geometrical analysis of the tooth meshing action to develop a semi-empirical formula for dynamic tooth load. The formula takes into consideration the gear geometry and manufacturing parameters as well as the dynamic characteristics of the system.
Requirement of the Nitrogen Starvation-Induced Protein Sll0783 for Polyhydroxybutyrate Accumulation in
Synechocystis
sp. Strain PCC 6803
Authors: Schlebusch Maximilian , Forchhammer Karl
Published: July 2010

Nitrogen is often a limiting nutrient in natural habitats. Therefore, cyanobacteria have developed multiple responses, which are controlled by transcription factor NtcA and the PII-signaling protein, to adapt to nitrogen deficiency. Transcriptional analyses of
Synechocystis
sp. strain PCC 6803 under nitrogen-deficient conditions revealed a highly induced gene (
sll0783
) which is annotated as encoding a conserved protein with an unknown function. This gene is part of a cluster of seven genes and has potential NtcA-binding sites in the upstream region. Homologues of this cluster occur in some unicellular, nondiazotrophic cyanobacteria and in several
Alpha
,
Beta
-, and
Gammaproteobacteria
, as well as in some Gram-positive bacteria. Most of the heterotrophic bacteria harboring this gene cluster are able to fix nitrogen and to produce polyhydroxybutyrate (PHB), whereas of the cyanobacteria, only
Synechocystis
sp. strain PCC 6803 can accumulate PHB. In this work, a
Synechocystis
sp. strain PCC 6803
sll0783
gene knockout mutant is characterized. This mutant is unable to accumulate PHB, a carbon and energy storage compound. In contrast, the levels of the carbon storage compound glycogen and the PHB precursor acetyl coenzyme A were similar to those of the wild type, indicating that the PHB-deficient phenotype does not likely result from a global deficiency in carbon metabolism. A specific deficiency in PHB synthesis was implied by the fact that the mutant exhibits impaired PHB synthase activity during prolonged nitrogen starvation. However, the expression of PHB synthase-encoding genes was not strongly affected in the mutant, suggesting that the impaired PHB synthase activity observed depends on a posttranscriptional process in which the product of
sll0783
is involved.
Interplay between Wheat Cultivars, Biocontrol Pseudomonads, and Soil
Authors: Meyer Joana Beatrice , Lutz Matthias Peter , Frapolli Michele , Péchy-Tarr Maria , Rochat Laurène , Keel Christoph , Défago Geneviève , Maurhofer Monika
Published: July 2010

There is a significant potential to improve the plant-beneficial effects of root-colonizing pseudomonads by breeding wheat genotypes with a greater capacity to sustain interactions with these bacteria. However, the interaction between pseudomonads and crop plants at the cultivar level, as well as the conditions which favor the accumulation of beneficial microorganisms in the wheat rhizosphere, is largely unknown. Therefore, we characterized the three Swiss winter wheat (
Triticum aestivum
) cultivars Arina, Zinal, and Cimetta for their ability to accumulate naturally occurring plant-beneficial pseudomonads in the rhizosphere. Cultivar performance was measured also by the ability to select for specific genotypes of 2,4-diacetylphloroglucinol (DAPG) producers in two different soils. Cultivar-specific differences were found; however, these were strongly influenced by the soil type. Denaturing gradient gel electrophoresis (DGGE) analysis of fragments of the DAPG biosynthetic gene
phlD
amplified from natural
Pseudomonas
rhizosphere populations revealed that
phlD
diversity substantially varied between the two soils and that there was a cultivar-specific accumulation of certain
phlD
genotypes in one soil but not in the other. Furthermore, the three cultivars were tested for their ability to benefit from
Pseudomonas
inoculants. Interestingly, Arina, which was best protected against
Pythium ultimum
infection by inoculation with
Pseudomonas fluorescens
biocontrol strain CHA0, was the cultivar which profited the least from the bacterial inoculant in terms of plant growth promotion in the absence of the pathogen. Knowledge gained of the interactions between wheat cultivars, beneficial pseudomonads, and soil types allows us to optimize cultivar-soil combinations for the promotion of growth through beneficial pseudomonads. Additionally, this information can be implemented by breeders into a new and unique breeding strategy for low-input and organic conditions.
Phagocytosis ofCryptococcus neoformansby, and Nonlytic Exocytosis from,Acanthamoeba castellanii
Authors: Chrisman Cara J. , Alvarez Mauricio , Casadevall Arturo
Published: July 2010

Cryptococcus neoformans, an encapsulated, pathogenic yeast, is endowed with a variety of virulence factors, including a polysaccharide capsule. During mammalian infection, the outcome of the interaction betweenC. neoformansand macrophages is central to determining the fate of the host. Previous studies have shown similarities between the interaction ofC. neoformanswith macrophages and with amoebae, resulting in the proposal that fungal virulence for mammals originated from selection by amoeboid predators. In this study, we investigated the interaction ofC. neoformanswith the soil amoebaAcanthamoeba castellanii. Comparison of phagocytic efficiency of the wild type, nonencapsulated mutants, and complemented strains showed that the capsule was antiphagocytic for amoebae. Capsular enlargement was associated with a significant reduction in phagocytosis, suggesting that this phenomenon protects against ingestion by phagocytic predators.C. neoformansvar.neoformanscells were observed to exit amoebae several hours after ingestion, in a process similar to the recently described nonlytic exocytosis from macrophages. Cryptococcal exocytosis from amoebae was dependent on the strain and on actin and required fungal viability. Additionally, the presence of a capsule was inversely correlated with the likelihood of extrusion in certain strains. In summary, nonlytic exocytosis from amoebae provide another parallel to observations in fungus-macrophage interactions. These results provide additional support for the notion that some mechanisms of virulence observed during mammalian infection originated, and were selected for, by environmental interactions.
Modeling the Effect of Abrupt Acid and Osmotic Shifts within the Growth Region and across Growth Boundaries on Adaptation and Growth of
Listeria monocytogenes
Authors: Le Marc Y. , Skandamis P. N. , Belessi C. I. A. , Merkouri S. I. , George S. M. , Gounadaki A. S. , Schvartzman S. , Jordan K. , Drosinos E. H. , Baranyi J.
Published: July 2010

This study aims to model the effects of acid and osmotic shifts on the intermediate lag time of
Listeria monocytogenes
at 10°C in a growth medium. The model was developed from data from a previous study (C. I. A. Belessi, Y. Le Marc, S. I. Merkouri, A. S. Gounadaki, S. Schvartzman, K. Jordan, E. H. Drosinos, and P. N. Skandamis, submitted for publication) on the effects of osmotic and pH shifts on the kinetics of
L. monocytogenes
. The predictive ability of the model was assessed on new data in milk. The effects of shifts were modeled through the dependence of the parameter
h
0
(“work to be done” prior to growth) induced on the magnitude of the shift and/or the stringency of the new environmental conditions. For shifts across the boundary, the lag time was found to be affected by the length of time for which the microorganisms were kept at growth-inhibiting conditions. The predicted concentrations of
L. monocytogenes
in milk were overestimated when the effects of this shift were not taken into account. The model proved to be suitable to describe the effects of osmotic and acid shifts observed both within the growth domain and across the growth boundaries of
L. monocytogenes
.
Mesophilic Fermentation of Renewable Biomass: Does Hydraulic Retention Time Regulate Methanogen Diversity?
Authors: Krakat Niclas , Schmidt Stefan , Scherer Paul
Published: July 2010

The present long-term study (about 1,100 days) monitored the diversity of methanogens during the mesophilic, anaerobic digestion of beet silage. Six fermentor samples were analyzed by ribosomal RNA gene restriction analysis, fluorescence
in situ
hybridization, and fluorescence microscopy. Hydrogenotrophic methanogens dominated within the population in all samples analyzed. Multidimensional scaling revealed that a rapid decrease in hydraulic retention time resulted in increased species richness, which in turn led to slightly higher CH
4
yields.
Effect of Nitric Oxide on Anammox Bacteria
Authors: Kartal Boran , Tan Nico C. G. , Van de Biezen Erwin , Kampschreur Marlies J. , Van Loosdrecht Mark C. M. , Jetten Mike S. M.
Published: July 2010

The effects of nitrogen oxides on anammox bacteria are not well known. Therefore, anammox bacteria were exposed to 3,500 ppm nitric oxide (NO) in the gas phase. The anammox bacteria were not inhibited by the high NO concentration but rather used it to oxidize additional ammonium to dinitrogen gas under conditions relevant to wastewater treatment.
Evolutionary Dynamics of Insertion Sequences in Relation to the Evolutionary Histories of the Chromosome and Symbiotic Plasmid Genes of
Rhizobium etli
Populations
Authors: Lozano Luis , Hernández-González Ismael , Bustos Patricia , Santamaría Rosa I. , Souza Valeria , Young J. Peter W. , Dávila Guillermo , González Víctor
Published: July 2010

Insertion sequences (IS) are mobile genetic elements that are distributed in many prokaryotes. In particular, in the genomes of the symbiotic nitrogen-fixing bacteria collectively known as rhizobia, IS are fairly abundant in plasmids or chromosomal islands that carry the genes needed for symbiosis. Here, we report an analysis of the distribution and genetic conservation of the IS found in the genome of
Rhizobium etli
CFN42 in a collection of 87
Rhizobium
strains belonging to populations with different geographical origins. We used PCR to generate presence/absence profiles of the 39 IS found in
R. etli
CFN42 and evaluated whether the IS were located in consistent genomic contexts. We found that the IS from the symbiotic plasmid were frequently present in the analyzed strains, whereas the chromosomal IS were observed less frequently. We then examined the evolutionary dynamics of these strains based on a population genetic analysis of two chromosomal housekeeping genes (
glyA
and
dnaB
) and three symbiotic sequences (
nodC
and the two IS elements). Our results indicate that the IS contained within the symbiotic plasmid have a higher degree of genomic context conservation, lower nucleotide diversity and genetic differentiation, and fewer recombination events than the chromosomal housekeeping genes. These results suggest that the
R. etli
populations diverged recently in Mexico, that the symbiotic plasmid also had a recent origin, and that the IS elements have undergone a process of cyclic infection and expansion.
Prolyl Aminopeptidase from
Streptomyces thermoluteus
subsp.
fuscus
Strain NBRC14270 and Synthesis of Proline-Containing Peptides by Its S144C Variant
Authors: Yamamoto Yukihiro , Usuki Hirokazu , Iwabuchi Masaki , Hatanaka Tadashi
Published: July 2010

We specifically examined an exopeptidase, prolyl aminopeptidase (PAP), as a target for synthesis of proline-containing peptides. A PAP from
Streptomyces thermoluteus
subsp.
fuscus
NBRC14270 (PAP14270) was obtained using sequence-based screening. From PAP14270, 144Ser was replaced by Cys (scPAP14270) to give aminolysis activity. In contrast to wild-type PAP14270, scPAP14270 produced a polymer of proline benzyl ester and cyclo[Pro-Pro]. The product mass was confirmed using liquid chromatography-mass spectrometry (LC/MS). Several factors affecting the reaction, such as the pH, concentration of the substrate, and reaction time, were measured to determine their effects. Furthermore, a correlation was found between substrate specificity in proline peptide synthesis and the log
D
value of acyl acceptors in aminolysis catalyzed by scPAP14270. Results showed that dipeptide synthesis proceeded in a weakly acidic environment and that cyclization and polymerization occurred under alkaline conditions. Furthermore, results suggest that almost all amino acid esters whose log
D
value is greater than 0, except hydroxyproline benzyl ester (Hyp-OBzl), can be recognized as acyl acceptors. These findings support the use of PAPs as a tool for production of physiologically active proline peptides.
Enhanced Production of a Plant Monoterpene by Overexpression of the 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Catalytic Domain in
Saccharomyces cerevisiae
Authors: Rico Juan , Pardo Ester , Orejas Margarita
Published: July 2010

Linalool production was evaluated in different
Saccharomyces cerevisiae
strains expressing the
Clarkia breweri
linalool synthase gene (
LIS
). The wine strain T
73
was shown to produce higher levels of linalool than conventional laboratory strains (i.e., almost three times the amount). The performance of this strain was further enhanced by manipulating the endogenous mevalonate (MVA) pathway: deregulated overexpression of the rate-limiting 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) doubled linalool production. In a haploid laboratory strain, engineering of this key step also improved linalool yield.
Role of Aspergillus fumigatus DvrA in Host Cell Interactions and Virulence
Authors: Ejzykowicz Daniele E. , Solis Norma V. , Gravelat Fabrice N. , Chabot Josee , Li Xuexian , Sheppard Donald C. , Filler Scott G.
Published: July 2010

The transcription factors that regulate
Aspergillus fumigatus
interactions with host cells and virulence are incompletely defined. We investigated the role of the putative C2H2 transcription factor DvrA in governing these processes. Although DvrA was identified by its limited homology to
Candida albicans
Bcr1, a Δ
dvrA
mutant strain of
A. fumigatus
had wild-type adherence to host constituents
in vitro
. However, it had increased capacity to damage both endothelial cells and a pulmonary epithelial cell line compared to the ability of the wild-type strain and a Δ
dvrA
::
dvrA
-complemented strain. This increase in damage required direct contact between the mutant and host cells. The Δ
dvrA
mutant also stimulated greater CCL20, interleukin-8, and tumor necrosis factor mRNA expression in a pulmonary epithelial cell line compared to levels induced by the control strains. Also, it was resistant to nikkomycin Z, suggesting an altered cell wall composition. As predicted by these
in vitro
results, the Δ
dvrA
mutant had increased virulence and stimulated a greater pulmonary inflammatory response than the wild-type strain and Δ
dvrA
::
dvrA
-complemented strains in the nonneutropenic mouse model of invasive pulmonary aspergillosis. These results indicate that DvrA influences
A. fumigatus
virulence as well as its capacity to damage host cells and stimulate a proinflammatory response.
Sulfate Assimilation Mediates Tellurite Reduction and Toxicity in Saccharomyces cerevisiae
Authors: Ottosson Lars-Göran , Logg Katarina , Ibstedt Sebastian , Sunnerhagen Per , Käll Mikael , Blomberg Anders , Warringer Jonas
Published: July 2010

Despite a century of research and increasing environmental and human health concerns, the mechanistic basis of the toxicity of derivatives of the metalloid tellurium, Te, in particular the oxyanion tellurite, Te(IV), remains unsolved. Here, we provide an unbiased view of the mechanisms of tellurium metabolism in the yeast
Saccharomyces cerevisiae
by measuring deviations in Te-related traits of a complete collection of gene knockout mutants. Reduction of Te(IV) and intracellular accumulation as metallic tellurium strongly correlated with loss of cellular fitness, suggesting that Te(IV) reduction and toxicity are causally linked. The sulfate assimilation pathway upstream of Met17, in particular, the sulfite reductase and its cofactor siroheme, was shown to be central to tellurite toxicity and its reduction to elemental tellurium. Gene knockout mutants with altered Te(IV) tolerance also showed a similar deviation in tolerance to both selenite and, interestingly, selenomethionine, suggesting that the toxicity of these agents stems from a common mechanism. We also show that Te(IV) reduction and toxicity in yeast is partially mediated via a mitochondrial respiratory mechanism that does not encompass the generation of substantial oxidative stress. The results reported here represent a robust base from which to attack the mechanistic details of Te(IV) toxicity and reduction in a eukaryotic organism.
Subtelomeric Silencing of the
MTL3
Locus of Candida glabrata Requires yKu70, yKu80, and Rif1 Proteins
Authors: Ramírez-Zavaleta Candy Y. , Salas-Delgado Griselda E. , De Las Peñas Alejandro , Castaño Irene
Published: July 2010

Candida glabrata
is a haploid opportunistic fungal pathogen that is phylogenetically related to
Saccharomyces cerevisiae
. Even though
C. glabrata
has no known sexual cycle, it contains, like
S. cerevisiae
, three mating type-like loci (
MTL
) called
MTL1
,
MTL2
, and
MTL3
, as well as most of the genes required for mating, meiosis, and sporulation.
MTL1
is localized at an internal position on chromosome B and is thought to be the locus corresponding to the
MAT
locus in
S. cerevisiae
.
MTL2
and
MTL3
are localized close to two telomeres on different chromosomes (29.4 kb from Chr E-L and 10.5 kb from Chr B-L, respectively). By using
URA3
reporter gene insertions at the three
MTL
loci, we found that in contrast to the case for
S. cerevisiae
, only
MTL3
is subject to transcriptional silencing while
MTL2
is transcriptionally active, and this is in agreement with previously reported data. We found that the silencing of
MTL3
is nucleated primarily at the left telomere of chromosome B and spreads over 12 kb to
MTL3
, rather than nucleating at flanking, closely positioned
cis
-acting silencers, like those flanking
HMR
and
HML
of
S. cerevisiae
. Interestingly, the silencing of
MTL3
absolutely requires the yKu70, yKu80, and Rif1 proteins, in sharp contrast to the silencing of the
HM
loci of
S. cerevisiae
. In addition, we found that several cell type-specific genes are expressed in
C. glabrata
regardless of the presence, or even absence, of mating type information at any of the
MTL
loci.
Comparative Study of the Roles of AhpC and KatE as Respiratory Antioxidants inBrucella abortus2308
Authors: Steele Kendra H. , Baumgartner John E. , Valderas Michelle Wright , Roop R. Martin
Published: July 2010

Brucellastrains are exposed to potentially toxic levels of H2O2both as a consequence of their aerobic metabolism and through the respiratory burst of host phagocytes. To evaluate the relative contributions of the sole catalase KatE and the peroxiredoxin AhpC produced by these strains in defense against H2O2-mediated toxicity, isogenickatE,ahpC, andkatE ahpCmutants were constructed and the phenotypic properties of these mutants compared with those of the virulent parental strainB. abortus2308. The results of these studies indicate that AhpC is the primary detoxifier of endogenous H2O2generated by aerobic metabolism. KatE, on the other hand, plays a major role in scavenging exogenous and supraphysiologic levels of H2O2, although this enzyme can play a supporting role in the detoxification of H2O2of endogenous origin if AhpC is absent.B. abortus ahpCandkatEmutants exhibit wild-type virulence in C57BL/6 and BALB/c mice, but theB. abortus ahpC katEdouble mutant is extremely attenuated, and this attenuation is not relieved in derivatives of C57BL/6 mice that lack NADPH oxidase (cybb) or inducible nitric oxide synthase (Nos2) activity. These experimental findings indicate that the generation of endogenous H2O2represents a relevant environmental stress thatB. abortus2308 must deal with during its residence in the host and that AhpC and KatE perform compensatory roles in detoxifying this metabolic H2O2.
A NAC for Regulating Metabolism: the Nitrogen Assimilation Control Protein (NAC) from
Klebsiella pneumoniae
Authors: Bender Robert A.
Published: July 2010

The nitrogen assimilation control protein (NAC) is a LysR-type transcriptional regulator (LTTR) that is made under conditions of nitrogen-limited growth. NAC's synthesis is entirely dependent on phosphorylated NtrC from the two-component Ntr system and requires the unusual sigma factor σ54 for transcription of the
nac
gene. NAC activates the transcription of σ70-dependent genes whose products provide the cell with ammonia or glutamate. NAC represses genes whose products use ammonia and also represses its own transcription. In addition, NAC also subtly adjusts other cellular functions to keep pace with the supply of biosynthetically available nitrogen.
Dual Biosynthesis Pathway for Longer-Chain Polyamines in the Hyperthermophilic Archaeon
Thermococcus kodakarensis
Authors: Morimoto Nanako , Fukuda Wakao , Nakajima Nanami , Masuda Takeaki , Terui Yusuke , Kanai Tamotsu , Oshima Tairo , Imanaka Tadayuki , Fujiwara Shinsuke
Published: July 2010

Long-chain and/or branched-chain polyamines are unique polycations found in thermophiles. Cytoplasmic polyamines were analyzed for cells cultivated at various growth temperatures in the hyperthermophilic archaeon
Thermococcus kodakarensis.
Spermidine [34] and
N
4
-aminopropylspermine [3(3)43] were identified as major polyamines at 60°C, and the amounts of
N
4
-aminopropylspermine [3(3)43] increased as the growth temperature rose. To identify genes involved in polyamine biosynthesis, a gene disruption study was performed. The open reading frames (ORFs) TK0240, TK0474, and TK0882, annotated as agmatine ureohydrolase genes, were disrupted. Only the TK0882 gene disruptant showed a growth defect at 85°C and 93°C, and the growth was partially retrieved by the addition of spermidine. In the TK0882 gene disruptant, agmatine and
N
1
-aminopropylagmatine accumulated in the cytoplasm. Recombinant TK0882 was purified to homogeneity, and its ureohydrolase characteristics were examined. It possessed a 43-fold-higher
k
cat
/

K
m

value for
N
1
-aminopropylagmatine than for agmatine, suggesting that TK0882 functions mainly as
N
1
-aminopropylagmatine ureohydrolase to produce spermidine. TK0147, annotated as spermidine/spermine synthase, was also studied. The TK0147 gene disruptant showed a remarkable growth defect at 85°C and 93°C. Moreover, large amounts of agmatine but smaller amounts of putrescine accumulated in the disruptant. Purified recombinant TK0147 possessed a 78-fold-higher
k
cat
/

K
m

value for agmatine than for putrescine, suggesting that TK0147 functions primarily as an aminopropyl transferase to produce
N
1
-aminopropylagmatine. In
T. kodakarensis
, spermidine is produced mainly from agmatine via
N
1
-aminopropylagmatine. Furthermore, spermine and
N
4
-aminopropylspermine were detected in the TK0147 disruptant, indicating that TK0147 does not function to produce spermine and long-chain polyamines.
Toxicity of the Colicin M Catalytic Domain Exported to the Periplasm Is FkpA Independent
Authors: Barnéoud-Arnoulet Aurélie , Barreteau Hélène , Touzé Thierry , Mengin-Lecreulx Dominique , Lloubès Roland , Duché Denis
Published: July 2010

Colicin M (ColM) is a bactericidal protein that kills sensitive cells by hydrolyzing lipid II, involved in the biosynthesis of cell wall peptidoglycan. It recognizes FhuA on the outer leaflet, and its translocation through the outer membrane depends on the energized Ton complex in the inner membrane. To be active in the periplasm, ColM must be translocated through the outer membrane and then interact with FkpA, a periplasmic protein that exhibits both
cis
- and
trans
-peptidylprolyl isomerase (PPiase) and chaperon activities. In an attempt to directly target ColM to the periplasm of the producing bacteria, we fused the presequence of OmpA to ColM (sp-ColM). We found that expression of this hybrid protein in an
Escherichia coli
strain devoid of ColM immunity protein (Cmi) was bactericidal. We showed that sp-ColM was correctly expressed, processed, and associated with the inner membrane. sp-ColM toxicity was related to its enzymatic activity and did not rely on the TonB import proteins or the FhuA receptor. The presence of both activity domains of FkpA was still required for sp-ColM activity. Analyses of deletion mutants of sp-ColM show that the domain required for toxicity corresponds to the C-terminal last 153 amino acids of ColM. Like the full-length protein, this domain is not active in the presence of the immunity protein Cmi. On the other hand, it does not require FkpA for toxic activity.