bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence of Cysticercus bovis in Australian cattle
Authors: Pearse BHG , Traub RJ , Davis A , Cobbold R , Vanderlinde PB
Published: June 2010

Objective  The first national abattoir survey of Cysticercus bovis (‘beef measles’) in cattle was conducted in February 2008.

Methods  During the data collection period, 493,316 cattle were subjected to standard postmortem procedures, including incision of the masseter and heart muscles. On‐site veterinarians were asked to record the location of any C. bovis cysts, as well as the National Livestock Identification System ear tag numbers of infected animals. Veterinarians were asked to submit samples for laboratory confirmation by histology and polymerase chain reaction testing.

Results  Of the 23 samples submitted, none was positive for C. bovis by either diagnostic method.

Conclusions  Occasional, isolated diagnoses of beef measles are still made in most states of Australia, but since the last regional surveys were conducted 30 years ago, when the estimated prevalence was 50 to 200 per 100,000 cattle slaughtered, the parasite has become extremely rare.
Production of standard blood components
Authors: Henschler R. , Müller M. M. , Pfeiffer H. U. , Seifried E. , Sireis W.
Published: June 2010

In the past three decades, the production of standard blood components from whole blood donations and from apheresis collections has reached a widely accepted high technical standard, paralleled by semi‐automated methodology to safeguard the stability of the production process and an internationally harmonized pharmaceutical quality. More recent methodological advances include pathogen inactivation as well as novel separation methods, which are challenging the previous achievements. The current review aims (1) to summarize the current status of implementation of novel techniques into the routine preparation process of blood components, (2) to discuss upcoming approaches in the area of component preparation, (3) to identify clinical needs that justify novel investigations into blood component quality and (4) to point out the status on the production of standard blood components by in vitro differentiation from stem and progenitor cells in vitro.
Culturing marine bacteria – an essential prerequisite for biodiscovery
Authors: Joint Ian , Mühling Martin , Querellou Joël
Published: June 2010

The potential for using marine microbes for biodiscovery is severely limited by the lack of laboratory cultures. It is a long‐standing observation that standard microbiological techniques only isolate a very small proportion of the wide diversity of microbes that are known in natural environments from DNA sequences. A number of explanations are reviewed. The process of establishing laboratory cultures may destroy any cell‐to‐cell communication that occurs between organisms in the natural environment and that are vital for growth. Bacteria probably grow as consortia in the sea and reliance on other bacteria for essential nutrients and substrates is not possible with standard microbiological approaches. Such interactions should be considered when designing programmes for the isolation of marine microbes. The benefits of novel technologies for manipulating cells are reviewed, including single cell encapsulation in gel micro‐droplets. Although novel technologies offer benefits for bringing previously uncultured microbes into laboratory culture, many useful bacteria can still be isolated using variations of plating techniques. Results are summarized for a study to culture bacteria from a long‐term observatory station in the English Channel. Bacterial biodiversity in this assemblage has recently been characterized using high‐throughput sequencing techniques. Although Alphaproteobacteria dominated the natural bacterial assemblage throughout the year, Gammaproteobacteria were the most frequent group isolated by plating techniques. The use of different gelling agents and the addition of ammonium to seawater‐based agar did lead to the isolation of a higher proportion of Alphaproteobacteria. Variation in medium composition was also able to increase the recovery of other groups of particular interest for biodiscovery, such as Actinobacteria.
Marriage and Family Therapy Faculty Members' Balance of Work and Personal Life
Authors: Matheson Jennifer L. , Rosen Karen H.
Published: June 2010

A sense of imbalance is common among both professors and therapists, though few studies have been published examining the work and personal life balance of those who work in both professions simultaneously. Using in‐depth telephone interviews, this study examined the work and personal life balance of 16 marriage and family therapy (MFT) faculty members. Results showed that six were satisfied with their balance, six were dissatisfied, and four were “middle of the road.” Men, older participants, and those who were in their career longer were more likely to report feeling satisfied with their balance. Internal indicators of their balance included family and workplace messages, health indicators, feelings of contentment, and congruence with personal values. Child and relationship status, tenure status, and gender issues also impacted their sense of balance. Specific balance enhancers and reducers were highlighted, and participants discussed coping strategies and recommendations for other MFT faculty members. Clinical, training, and career implications are discussed.
A comparison of canopy evapotranspiration for maize and two perennial grasses identified as potential bioenergy crops
Authors: HICKMAN GEORGE C. , VANLOOCKE ANDY , DOHLEMAN FRANK G. , BERNACCHI CARL J.
Published: June 2010

In the Midwestern US, perennial rhizomatous grasses (PRGs) are considered one of the most promising vegetation types to be used as a cellulosic feedstock for renewable energy production. The potential widespread use of biomass crops for renewable energy production has sparked numerous environmental concerns, including the impacts of land‐use change on the hydrologic cycle. We predicted that total seasonal evapotranspiration (ET) would be higher for PRGs relative to maize resulting from higher leaf area and a prolonged growing season. We further predicted that, compared with maize, higher aboveground biomass associated with PRGs would offset the higher ET and increase water‐use efficiency (WUE) in the context of biomass harvests for liquid biofuel production. To test these predictions, ET was estimated during the 2007 growing season for replicated plots of Miscanthus×giganteus (miscanthus), Panicum virgatum (switchgrass), and Zea mays (maize) using a residual energy balance approach. The combination of a 25% higher mean latent heat flux (λET) and a longer growing season resulted in miscanthus having ca. 55% higher cumulative ET over the growing season compared with maize. Cumulative ET for switchgrass was also higher than maize despite similar seasonal‐mean λET. Based on total harvested aboveground biomass, WUE was ca. 50% higher for maize relative to miscanthus; however, when WUE calculated from only maize grain biomass was compared with WUE calculated from miscanthus harvested aboveground biomass, this difference disappeared. Although WUE between maize and miscanthus differed postsenescence, there were no differences in incremental WUE throughout the growing season. Despite initial predictions, aboveground biomass for switchgrass was less than maize; thus WUE was substantially lower for switchgrass than for either maize scenario. These results indicate that changes in ET due to large‐scale implementation of PRGs in the Midwestern US would likely influence local and regional hydrologic cycles differently than traditional row crops.
Fasting tests of insulin secretion and sensitivity predict future prediabetes in Japanese with normal glucose tolerance
Authors: Onishi Yukiko , Hayashi Tomoshige , Sato Kyoko Kogawa , Ogihara Takehide , Kuzuya Nobuaki , Anai Motonobu , Tsukuda Katsunori , Boyko Edward J , Fujimoto Wilfred Y , Kikuchi Masatoshi
Published: June 2010

Aims/Introduction:  Reduced insulin sensitivity and secretion are important in the pathogenesis of type 2 diabetes. Their relationships to prediabetes, impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) have been previously studied with the oral glucose tolerance test (OGTT). We investigated whether or not baseline measures of insulin secretion and sensitivity obtained from fasting blood specimens were related to the development of prediabetes and how these measures compared with those based on the OGTT.

Materials and Methods:  In 152 Japanese subjects with normal glucose tolerance, we measured baseline plasma glucose and insulin after an overnight fast and during a 75 g OGTT, insulin resistance index (homeostasis model assessment [HOMA‐IR]), and insulin secretion (insulinogenic index [30 min insulin − fasting insulin] ÷ [30 min glucose − fasting glucose] or HOMA‐β).

Results:  At a 5–6 year (mean 5.7 years) follow‐up examination, we confirmed 36 cases of prediabetes. After adjusting for age, sex, family history of diabetes, body mass index, and 2‐h plasma glucose, the odds ratio comparing the lowest tertile (≤0.82) of insulinogenic index with the highest tertile (≥1.43) was 6.98 (95% confidence interval, 1.96–24.85) and was 10.72 (2.08–55.3) comparing the lowest tertile (≤76.3) of HOMA‐β with the highest tertile (≥122.1), whereas the respective odds ratios of HOMA‐IR were 3.74 (1.03–13.57) and 10.89 (1.93–61.41) comparing the highest tertile (≥1.95) with the lowest tertile (≤1.25).

Conclusions:  Lower insulin secretion and sensitivity are independent risk factors for prediabetes. Clinically practical identification of those at risk for prediabetes is obtainable from HOMA‐β and HOMA‐IR, both of which are measured in fasting state. (J Diabetes Invest, doi: 10.1111.j.2040‐1124.2010.00041.x, 2010)
Low NOx and Low Smoke Operation of a Diesel Engine Using Gasolinelike Fuels
Authors: Kalghatgi Gautam , Hildingsson Leif , Johansson Bengt
Published: June 2010

Much of the technology in advanced diesel engines, such as high injection pressures, is aimed at overcoming the short ignition delay of conventional diesel fuels to promote premixed combustion in order to reduce NOx and smoke. Previous work in a 2 l single-cylinder diesel engine with a compression ratio of 14 has demonstrated that gasoline fuel, because of its high ignition delay, is very beneficial for premixed compression-ignition compared with a conventional diesel fuel. We have now done similar studies in a smaller—0.537 l—single-cylinder diesel engine with a compression ratio of 15.8. The engine was run on three fuels of very different auto-ignition quality—a typical European diesel fuel with a cetane number (CN) of 56, a typical European gasoline of 95 RON and 85 MON with an estimated CN of 16 and another gasoline of 84 RON and 78 MON (estimated CN of 21). The previous results with gasoline were obtained only at 1200 rpm—here we compare the fuels also at 2000 rpm and 3000 rpm. At 1200 rpm, at low loads (∼4 bars indicated mean effective pressure (IMEP)) when smoke is negligible, NOx levels below 0.4 g/kWh can be easily attained with gasoline without using exhaust gas recirculation (EGR), while this is not possible with the 56 CN European diesel. At these loads, the maximum pressure-rise rate is also significantly lower for gasoline. At 2000 rpm, with 2 bars absolute intake pressure, NOx can be reduced below 0.4 g/kW h with negligible smoke (FSN<0.1) with gasoline between 10 bars and 12 bars IMEP using sufficient EGR, while this is not possible with the diesel fuel. At 3000 rpm, with the intake pressure at 2.4 bars absolute, NOx of 0.4 g/kW h with negligible smoke was attainable with gasoline at 13 bars IMEP. Hydrocarbon and CO emissions are higher for gasoline and will require after-treatment. High peak heat release rates can be alleviated using multiple injections. Large amounts of gasoline, unlike diesel, can be injected very early in the cycle without causing heat release during the compression stroke and this enables the heat release profile to be shaped.
Combustion and Emissions Characterization of Soy Methyl Ester Biodiesel Blends in an Automotive Turbocharged Diesel Engine
Authors: Moscherosch Benjamin W. , Polonowski Christopher J. , Miers Scott A. , Naber Jeffrey D.
Published: June 2010

Recent increases in petroleum fuel costs, corporate average fuel economy (CAFE) regulations, and environmental concerns about CO2 emissions from petroleum based fuels have created an increased opportunity for diesel engines and non-petroleum renewable fuels such as biodiesel. Additionally, the Environmental Protection Agencies Tier II heavy duty and light duty emissions regulations require significant reductions in NOx and diesel particulate matter emissions for diesel engines. As a result, the diesel engine and aftertreatment system is a highly calibrated system that is sensitive to fuel characteristics. This study focuses on the impact of soy methyl ester biodiesel blends on combustion performance, NOx, and carbonaceous soot matter emissions. Tests were completed using a 1.9 L, turbocharged direct injection diesel engine using commercially available 15 ppm ultra low sulfur (ULS) diesel, a soy methyl ester B20 biodiesel blend (20 vol % B100 and 80 vol % ULS diesel), and a pure soy methyl ester biodiesel. Results show a reduction in NOx and carbonaceous soot matter emissions, and an increase in brake specific fuel consumption with the use of biodiesel. Further, traditional methodology assumes that diesel fuels with a high cetane number have a reduced ignition delay. However, results from this study show the cetane number is not the only parameter effecting ignition delay due to increased diffusion burn.
Study of a High Performance AFM Probe-Based Microscribing Process
Authors: Bourne Keith , Kapoor Shiv G. , DeVor Richard E.
Published: June 2010

In this paper, a mechanical microscribing process is described that combines AFM probe-based microscribing with a five-axis microscale machine tool motion platform in order to achieve high scribing speeds, a large working volume, and the capability of cutting curvilinear patterns of grooves. An experiment is described that demonstrates groove formation, groove shape, and tool wear when long grooves are formed using multiple tool passes. A second more systematic experiment is described in which short-distance single-pass cutting tests were used to explore the effects of cutting speed, nominal tool load, and AFM probe mounting angle on groove geometry, tool wear, effective rake angle, and chip formation. Lastly, an experiment is described in which a long curvilinear groove is cut. It is shown that the most well-formed grooves were cut and acceptable tool wear was achieved, when using a high cutting speed, high nominal tool load, and low probe mounting angle. The capability of cutting grooves as long at 82 mm but with depths of only a few hundred nanometers, using a single tool pass at cutting speeds as high at 25 mm/min is demonstrated.
Rapid Nanomanufacturing of Metallic Break Junctions Using Focused Ion Beam Scratching and Electromigration
Authors: Asghar Waseem , Ramachandran Priyanka P. , Adewumi Adegbenro , Noor Mohammud R. , Iqbal Samir M.
Published: June 2010

Break junctions provide a direct way to interrogate electrical transport properties of molecules, in pursuit of molecular electronics devices. A number of approaches are used for the fabrication of break junctions, including optical/e-beam lithography, electromigration, mechanical control of suspended conductive electrodes/strips, and electrochemical deposition of conductive material and nanowires. All approaches either require serial and slow e-beam writing of nanoscale gaps or suffer from low-yield of nanogap electrode devices. Here, we report the use of focused ion beam (FIB) to “scratch” and remove a thin layer of gold from 3 μm wide lines. The scratch results in thinning of the metal line and subsequent current-driven electromigration results into nanogaps at precise locations with high yield of devices. Combining FIB scratching with electromigration provides an elegant approach of creating nanoscale break junctions at an exact location and with a very narrow distribution of the nanogap sizes. Current-voltage measurements are done using a probe station before and after FIB scratch, and after the breaks were formed. Most of the gaps fall within 200–300 nm range and show negligible conductivity. The approach provides a novel, rapid, and high-throughput manufacturing approach of break junction fabrication that can be used for molecular sensing.
The Growing Human Footprint on Coastal and Open-Ocean Biogeochemistry
Authors: Doney Scott C.
Published: June 2010

Climate change, rising atmospheric carbon dioxide, excess nutrient inputs, and pollution in its many forms are fundamentally altering the chemistry of the ocean, often on a global scale and, in some cases, at rates greatly exceeding those in the historical and recent geological record. Major observed trends include a shift in the acid-base chemistry of seawater, reduced subsurface oxygen both in near-shore coastal water and in the open ocean, rising coastal nitrogen levels, and widespread increase in mercury and persistent organic pollutants. Most of these perturbations, tied either directly or indirectly to human fossil fuel combustion, fertilizer use, and industrial activity, are projected to grow in coming decades, resulting in increasing negative impacts on ocean biota and marine resources.
Radiocarbon-Based Chronology for Dynastic Egypt
Authors: Ramsey Christopher Bronk , Dee Michael W. , Rowland Joanne M. , Higham Thomas F. G. , Harris Stephen A. , Brock Fiona , Quiles Anita , Wild Eva M. , Marcus Ezra S. , Shortland Andrew J.
Published: June 2010

Date with the Pharaohs

Ancient Egypt dominated the Mediterranean world for several thousand years. However, the absolute chronology of this civilization has been uncertain, even though the sequence of rulers is well documented.

Bronk Ramsey
et al.

(p.
1554
; see the Perspective by

Bruins

) now provide a detailed radiocarbon-based record using more than 200 samples that spans much of this time and reduces uncertainties in some cases to less than 20 years. To avoid artifacts, the authors dated only short-lived plant remains from known contexts (i.e., that were associated with specific reigns). They then used the known reign lengths as a further constraint to obtain a final chronology. The final dates agree most closely with the previous older chronology but force some revisions to the timing of events in the Old Kingdom, the period in the third millennium B.C.E. when Egypt attained its first continuous peak of civilization.
HDL
miR
-ed Down by
SREBP
Introns
Authors: Brown Michael S. , Ye Jin , Goldstein Joseph L.
Published: June 2010

MicroRNAs that reduce cholesterol export from cells are encoded in the same genes that increase cholesterol synthesis.
Ocean Acidification Unprecedented, Unsettling
Authors: Kerr Richard A.
Published: June 2010

Humans are caught up in a grand planetary experiment of lowering the ocean's pH, with a potentially devastating toll on marine life.
The Dirt on Ocean Garbage Patches
Authors: Kaiser Jocelyn
Published: June 2010

Their biological impact is uncertain and their makeup, misunderstood.
Rapid Quantification of Viable
Campylobacter
Bacteria on Chicken Carcasses, Using Real-Time PCR and Propidium Monoazide Treatment, as a Tool for Quantitative Risk Assessment
Authors: Josefsen M. H. , Löfström C. , Hansen T. B. , Christensen L. S. , Olsen J. E. , Hoorfar J.
Published: June 2010

A number of intervention strategies against
Campylobacter
-contaminated poultry focus on postslaughter reduction of the number of cells, emphasizing the need for rapid and reliable quantitative detection of only viable
Campylobacter
bacteria. We present a new and rapid quantitative approach to the enumeration of food-borne
Campylobacter
bacteria that combines real-time quantitative PCR (Q-PCR) with simple propidium monoazide (PMA) sample treatment. In less than 3 h, this method generates a signal from only viable and viable but nonculturable (VBNC)
Campylobacter
bacteria with an intact membrane. The method's performance was evaluated by assessing the contributions to variability by individual chicken carcass rinse matrices, species of
Campylobacter
, and differences in efficiency of DNA extraction with differing cell inputs. The method was compared with culture-based enumeration on 50 naturally infected chickens. The cell contents correlated with cycle threshold (

C
T

) values (
R
2
= 0.993), with a quantification range of 1 × 10
2
to 1 × 10
7
CFU/ml. The correlation between the
Campylobacter
counts obtained by PMA-PCR and culture on naturally contaminated chickens was high (
R
2
= 0.844). The amplification efficiency of the Q-PCR method was not affected by the chicken rinse matrix or by the species of
Campylobacter
. No Q-PCR signals were obtained from artificially inoculated chicken rinse when PMA sample treatment was applied. In conclusion, this study presents a rapid tool for producing reliable quantitative data on viable
Campylobacter
bacteria in chicken carcass rinse. The proposed method does not detect DNA from dead
Campylobacter
bacteria but recognizes the infectious potential of the VBNC state and is thereby able to assess the effect of control strategies and provide trustworthy data for risk assessment.
Novel, Versatile, and Tightly Regulated Expression System for
E
scherichia coli
Strains
Authors: Choi Young J. , Morel Lyne , Le François Teffanie , Bourque Denis , Bourget Lucie , Groleau Denis , Massie Bernard , Míguez Carlos B.
Published: June 2010

A novel tightly regulated gene expression system was developed for
Escherichia coli
by applying the regulatory elements of the
Pseudomonas putida
F1
cym
and
cmt
operons to control target gene expression at the transcriptional level by using
p
-isopropylbenzoate (cumate) as an inducer. This novel expression system, referred to as the cumate gene switch, includes a specific expression vector, pNEW, that contains a partial T
5
phage promoter combined with the
Pseudomonas
-based synthetic operator and the
cymR
repressor protein-encoding gene designed to express constitutively in the host strain. The induction of transcription relies on the addition of the exogenous inducer (cumate), which is nontoxic to the culture, water soluble, and inexpensive. The characteristics and potential of the expression system were determined. Using flow cytometry and fed-batch fermentations, we have shown that, with the newly developed cumate-regulated system, (i) higher recombinant product yields can be obtained than with the pET (isopropyl-β-
d
-thiogalactopyranoside [IPTG])-induced expression system, (ii) expression is tightly regulated, (iii) addition of cumate quickly results in a fully induced and homogenous protein-expressing population in contrast to the bimodal expression profile of an IPTG-induced population, (iv) expression can be modulated by varying the cumate concentration, and (v) the cumate-induced population remains induced and fully expressing even at 8 h following induction, resulting in high yields of the target protein Furthermore, the cumate gene switch described in this article is applicable to a wide range of
E. coli
strains.
Transcriptomic Insights into the Physiology ofAspergillus nigerApproaching a Specific Growth Rate of Zero
Authors: Jørgensen Thomas R. , Nitsche Benjamin M. , Lamers Gerda E. , Arentshorst Mark , van den Hondel Cees A. , Ram Arthur F.
Published: June 2010

The physiology of filamentous fungi at growth rates approaching zero has been subject to limited study and exploitation. With the aim of uncoupling product formation from growth, we have revisited and improved the retentostat cultivation method forAspergillus niger. A new retention device was designed allowing reliable and nearly complete cell retention even at high flow rates. Transcriptomic analysis was used to explore the potential for product formation at very low specific growth rates. The carbon- and energy-limited retentostat cultures were highly reproducible. While the specific growth rate approached zero (<0.005 h−1), the growth yield stabilized at a minimum (0.20 g of dry weight per g of maltose). The severe limitation led to asexual differentiation, and the supplied substrate was used for spore formation and secondary metabolism. Three physiologically distinct phases of the retentostat cultures were subjected to genome-wide transcriptomic analysis. The severe substrate limitation and sporulation were clearly reflected in the transcriptome. The transition from vegetative to reproductive growth was characterized by downregulation of genes encoding secreted substrate hydrolases and cell cycle genes and upregulation of many genes encoding secreted small cysteine-rich proteins and secondary metabolism genes. Transcription of known secretory pathway genes suggests thatA. nigerbecomes adapted to secretion of small cysteine-rich proteins. The perspective is thatA. nigercultures as they approach a zero growth rate can be used as a cell factory for production of secondary metabolites and cysteine-rich proteins. We propose that the improved retentostat method can be used in fundamental studies of differentiation and is applicable to filamentous fungi in general.
Production of a New Thiopeptide Antibiotic, TP-1161, by a Marine
Nocardiopsis
Species
Authors: Engelhardt Kerstin , Degnes Kristin F. , Kemmler Michael , Bredholt Harald , Fjærvik Espen , Klinkenberg Geir , Sletta Håvard , Ellingsen Trond E. , Zotchev Sergey B.
Published: June 2010

Twenty-seven marine sediment- and sponge-derived actinomycetes with a preference for or dependence on seawater for growth were classified at the genus level using molecular taxonomy. Their potential to produce bioactive secondary metabolites was analyzed by PCR screening for genes involved in polyketide and nonribosomal peptide antibiotic synthesis. Using microwell cultures, conditions for the production of antibacterial and antifungal compounds were identified for 15 of the 27 isolates subjected to this screening. Nine of the 15 active extracts were also active against multiresistant Gram-positive bacterial and/or fungal indicator organisms, including vancomycin-resistant
Enterococcus faecium
and multidrug-resistant
Candida albicans
. Activity-guided fractionation of fermentation extracts of isolate TFS65-07, showing strong antibacterial activity and classified as a
Nocardiopsis
species, allowed the identification and purification of the active compound. Structure elucidation revealed this compound to be a new thiopeptide antibiotic with a rare aminoacetone moiety. The
in vitro
antibacterial activity of this thiopeptide, designated TP-1161, against a panel of bacterial strains was determined.
Deletion of a
fur
-Like Gene Affects Iron Homeostasis and Magnetosome Formation in
Magnetospirillum gryphiswaldense
Authors: Uebe René , Voigt Birgit , Schweder Thomas , Albrecht Dirk , Katzmann Emanuel , Lang Claus , Böttger Lars , Matzanke Berthold , Schüler Dirk
Published: June 2010

Magnetotactic bacteria synthesize specific organelles, the magnetosomes, which are membrane-enveloped crystals of the magnetic mineral magnetite (Fe
3
O
4
). The biomineralization of magnetite involves the uptake and intracellular accumulation of large amounts of iron. However, it is not clear how iron uptake and biomineralization are regulated and balanced with the biochemical iron requirement and intracellular homeostasis. In this study, we identified and analyzed a homologue of the
f
erric
u
ptake
r
egulator Fur in
Magnetospirillum gryphiswaldense
, which was able to complement a
fur
mutant of
Escherichia coli
. A
fur
deletion mutant of
M. gryphiswaldense
biomineralized fewer and slightly smaller magnetite crystals than did the wild type. Although the total cellular iron accumulation of the mutant was decreased due to reduced magnetite biomineralization, it exhibited an increased level of free intracellular iron, which was bound mostly to a ferritin-like metabolite that was found significantly increased in Mössbauer spectra of the mutant. Compared to that of the wild type, growth of the
fur
mutant was impaired in the presence of paraquat and under aerobic conditions. Using a Fur titration assay and proteomic analysis, we identified constituents of the Fur regulon. Whereas the expression of most known magnetosome genes was unaffected in the
fur
mutant, we identified 14 proteins whose expression was altered between the mutant and the wild type, including five proteins whose genes constitute putative iron uptake systems. Our data demonstrate that Fur is a regulator involved in global iron homeostasis, which also affects magnetite biomineralization, probably by balancing the competing demands for biochemical iron supply and magnetite biomineralization.
Structure and Function of CinD (YtjD) ofLactococcus lactis, a Copper-Induced Nitroreductase Involved in Defense against Oxidative Stress
Authors: Mermod Mélanie , Mourlane Frédéric , Waltersperger Sandro , Oberholzer Anselm E. , Baumann Ulrich , Solioz Marc
Published: June 2010

InLactococcus lactisIL1403, 14 genes are under the control of the copper-inducible CopR repressor. This so-called CopR regulon encompasses the CopR regulator, two putative CPx-type copper ATPases, a copper chaperone, and 10 additional genes of unknown function. We addressed here the function of one of these genes,ytjD, which we renamedcinD(copper-inducednitroreductase). Copper, cadmium, and silver inducedcinD in vivo, as shown by real-time quantitative PCR. A knockout mutant ofcinDwas more sensitive to oxidative stress exerted by 4-nitroquinoline-N-oxide and copper. Purified CinD is a flavoprotein and reduced 2,6-dichlorophenolindophenol and 4-nitroquinoline-N-oxide withkcatvalues of 27 and 11 s−1, respectively, using NADH as a reductant. CinD also exhibited significant catalase activityin vitro. The X-ray structure of CinD was resolved at 1.35 Å and resembles those of other nitroreductases. CinD is thus a nitroreductase which can protectL. lactisagainst oxidative stress that could be exerted by nitroaromatic compounds and copper.
Xer1-Mediated Site-Specific DNA Inversions and Excisions in
Mycoplasma agalactiae
Authors: Czurda Stefan , Jechlinger Wolfgang , Rosengarten Renate , Chopra-Dewasthaly Rohini
Published: June 2010

Surface antigen variation in
Mycoplasma agalactiae
, the etiologic agent of contagious agalactia in sheep and goats, is governed by site-specific recombination within the
vpma
multigene locus encoding the Vpma family of variable surface lipoproteins. This high-frequency Vpma phase switching was previously shown to be mediated by a Xer1 recombinase encoded adjacent to the
vpma
locus. In this study, it was demonstrated in
Escherichia coli
that the Xer1 recombinase is responsible for catalyzing
vpma
gene inversions between recombination sites (RS) located in the 5′-untranslated region (UTR) in all six
vpma
genes, causing cleavage and strand exchange within a 21-bp conserved region that serves as a recognition sequence. It was further shown that the outcome of the site-specific recombination event depends on the orientation of the two
vpma
RS, as direct or inverted repeats. While recombination between inverted
vpma
RS led to inversions, recombination between direct repeat
vpma
RS led to excisions. Using a newly developed excision assay based on the
lacZ
reporter system, we were able to successfully demonstrate under native conditions that such Xer1-mediated excisions can indeed also occur in the
M. agalactiae
type strain PG2, whereas they were not observed in the control
xer1
-disrupted VpmaY phase-locked mutant (PLMY), which lacks Xer1 recombinase. Unless there are specific regulatory mechanisms preventing such excisions, this might be the cost that the pathogen has to render at the population level for maintaining this high-frequency phase variation machinery.
Sensitivity of Influenza Rapid Diagnostic Tests to H5N1 and 2009 Pandemic H1N1 Viruses
Authors: Sakai-Tagawa Yuko , Ozawa Makoto , Tamura Daisuke , Le Mai thi Quynh , Nidom Chairul A. , Sugaya Norio , Kawaoka Yoshihiro
Published: June 2010

Simple and rapid diagnosis of influenza is useful for making treatment decisions in the clinical setting. Although many influenza rapid diagnostic tests (IRDTs) are available for the detection of seasonal influenza virus infections, their sensitivity for other viruses, such as H5N1 viruses and the recently emerged swine origin pandemic (H1N1) 2009 virus, remains largely unknown. Here, we examined the sensitivity of 20 IRDTs to various influenza virus strains, including H5N1 and 2009 pandemic H1N1 viruses. Our results indicate that the detection sensitivity to swine origin H1N1 viruses varies widely among IRDTs, with some tests lacking sufficient sensitivity to detect the early stages of infection when the virus load is low.
Clinical and Molecular Characteristics of Infections with CO
2
-Dependent Small-Colony Variants of
Staphylococcus aureus
Authors: Gómez-González Carmen , Acosta Joshi , Villa Jennifer , Barrado Laura , Sanz Francisca , Orellana M. Ángeles , Otero Joaquín R. , Chaves Fernando
Published: June 2010

Most
Staphylococcus aureus
small-colony variants (SCVs) are auxotrophs for menadione, hemin, or thymidine but rarely for CO
2
. We conducted a prospective investigation of all clinical cases of CO
2
-dependent
S. aureus
during a 3-year period. We found 14 CO
2
-dependent isolates of
S. aureus
from 14 patients that fulfilled all requirements to be considered SCVs, 9 of which were methicillin resistant. The clinical presentations included four cases of catheter-related bacteremia, one complicated by endocarditis; two deep infections (mediastinitis and spondylodiscitis); four wound infections; two respiratory infections; and two cases of nasal colonization. Pulsed-field gel electrophoresis typing showed that the 14 isolates were distributed into 4 types corresponding to sequence types ST125-
agr
group II (
agr
II), ST30-
agr
III, ST34-
agr
III, and ST45-
agr
I. An array hybridization technique performed on the 14 CO
2
-dependent isolates and 20
S. aureus
isolates with normal phenotype and representing the same sequence types showed that all possessed the enterotoxin gene cluster
egc
, as well as the genes for α-hemolysin and δ-hemolysin; biofilm genes
icaA
,
icaC
, and
icaD
; several microbial surface components recognizing adhesive matrix molecules (MSCRAMM) genes (
clfA
,
clfB
,
ebh
,
eno
,
fib
,
ebpS
,
sdrC
, and
vw
); and the
isaB
gene. Our study confirms the importance of CO
2
-dependent SCVs of
S. aureus
as significant pathogens. Clinical microbiologists should be aware of this kind of auxotrophy because recovery and identification are challenging and not routine. Further studies are necessary to determine the incidence of CO
2
auxotrophs of
S. aureus
, the factors that select these strains in the host, and the genetic basis of this type of auxotrophy.
Diagnostic Accuracy and Analytical Sensitivity of IDEIA Norovirus Assay for Routine Screening of Human Norovirus
Authors: Costantini Verónica , Grenz LaDonna , Fritzinger Angela , Lewis David , Biggs Christianne , Hale Antony , Vinjé Jan
Published: June 2010

Noroviruses (NoVs) are recognized as the leading cause of epidemic and sporadic acute gastroenteritis. Early detection of NoV is crucial to control the spread of the disease. In this study, we evaluated the diagnostic accuracy, analytical sensitivity, and analytical reactivity of the IDEIA Norovirus assay (an enzyme immunoassay [EIA]) in a prospective and retrospective study design. A total of 557 prospectively collected fecal samples and a panel of 97 archived fecal samples, including 21 different GI and GII genotypes, were tested by conventional reverse transcription-PCR (RT-PCR)/bidirectional sequencing, real-time RT-PCR, and electron microscopy. The sensitivity and specificity of the EIA were 57.6% and 91.9%, respectively. The sensitivity for detecting NoV in fecal samples from outbreaks improved from 44.1% when three samples were tested to 76.9% when five samples per outbreak were tested. The EIA was able to detect strains from 7 GI and 11 GII genotypes. The analytical sensitivity of the EIA was 3.1 × 10
6
and 1.6 × 10
7
virus particles g
−1
of fecal sample for NoV GI and GII strains, respectively. Most GII samples positive by EIA had a threshold cycle (

C
T

) of <26.5, and 50% of the GII samples negative by EIA had a

C
T

of >25.6, suggesting that, although strains from genotypes GI.8, GII.10, and GII.16 were not detected, the low sensitivity of the EIA is primarily caused by low virus concentration. In conclusion, the current EIA may be of use as a rapid screening test during a norovirus outbreak investigation when multiple fecal samples are available; however, sporadic samples should be tested by molecular methods.
Caught in the Act:
In Vivo
Development of Macrolide Resistance to
Campylobacter jejuni
Infection
Authors: Lindow J. C. , Poly F. , Tribble D. R. , Guerry P. , Carmolli M. P. , Baqar S. , Porter C. K. , Pierce K. K. , Darsley M. J. , Sadigh K. S. , Dill E. A. , Kirkpatrick B. D.
Published: June 2010

We report the first instance of macrolide resistance developing
in vivo
following appropriate antibiotic use in a healthy volunteer as a part of a controlled human infection with
Campylobacter jejuni. In vivo
development of macrolide resistance may be an important contributor to antibiotic resistance in
C. jejuni
.
Modifications to the Hemagglutinin Cleavage Site Control the Virulence of a Neurotropic H1N1 Influenza Virus
Authors: Sun Xiangjie , Tse Longping V. , Ferguson A Damon , Whittaker Gary R.
Published: June 2010

A key determinant of influenza virus pathogenesis is mutation in the proteolytic cleavage site of the hemagglutinin (HA). Typically, low-pathogenicity forms of influenza virus are cleaved by trypsin-like proteases, whereas highly pathogenic forms are cleaved by different proteases (e.g., furin). Influenza virus A/WSN/33 (WSN) is a well-studied H1N1 strain that is trypsin independent
in vitro
and has the ability to replicate in mouse brain. Previous studies have indicated that mutations in the neuraminidase (NA) gene allow the recruitment of an alternate protease (plasminogen/plasmin) for HA activation. In this study we have identified an additional mutation in the P2 position of the WSN HA cleavage site (S328Y) that appears to control virus spread in a plasmin-dependent manner. We reconstructed recombinant WSN viruses containing tyrosine (Y), phenylalanine (F), or serine (S) in the P2 position of the cleavage site. The Y328 and F328 viruses allowed plaque formation in the absence of trypsin, whereas the S328 virus was unable to form plaques under these conditions. In mice, Y328 and F328 viruses were able to efficiently spread following intracranial inoculation; in contrast, the S328 virus showed only limited infection of mouse brain. Following intranasal inoculation, all viruses could replicate efficiently, but with Y328 and F328 viruses showing a limited growth defect. We also show that wild-type HA (Y328) was more efficiently cleaved by plasmin than S328 HA. Our studies form the foundation for a more complete understanding of the molecular determinants of influenza virus pathogenesis and the role of the plasminogen/plasmin system in activating HA.
Addition-cyclization reactions of ethyl isothiocyanatoacetate with carboxylic acid hydrazides
Authors: Veverka Miroslav , Marchalín Miroslav
Published: June 2010

Ethyl (3-substituted 5-thioxo-1,2,4-triazolin-4-yl)acetates were prepared by addition-cyclization reaction of ethyl isothiocyanatoacetate with carboxylic acid hydrazides in the presence of sodium ethoxide. Thermal cyclization of the adduct in dimethylformamide afforded 1-acetamido-2-thiohydantoin. The effect of substituents on the cyclization course and the thione-thiol tautomerism are discussed.
Kinetics and mechanism of base-catalyzed cyclization of substituted amides and nitriles of hydantoic acid
Authors: Macháček Vladimír , Svobodová Gabriela , Štěrba Vojeslav
Published: June 2010

Rates of base-catalyzed cyclizations of 8 substituted derivatives of hydantoic acid amide type R3-NH(5)-CO(4)-NR2(3)-CH2(2)-CO(1)-NHR1 and 9 nitriles type R3-NH(5)-CO(4)-NR2(3)-CHR1(2)-CN have been measured in aqueous and methanolic media. The cyclization of the amides in aqueous medium is also accompanied by hydrolysis of the hydantoins formed. In some cases the hydrolysis rate constant is greater than the corresponding cyclization reaction rate constant. With the least reactive amides, the cyclization is also accompanied by hydrolysis of the amide group. The rate of the cyclization reactions in water is higher than that in methanol (at the same concentration of the lyate ions) by the factor of 10-100. Substitution of hydrogen at 3 and 5 positions by methyl or phenyl groups causes an acceleration of the cyclization reaction, whereas a substitution in the amide group causes a considerable retardation. The greatest acceleration of the cyclization (by as much as 4 orders) is caused by introduction of phenyl group to the N(5) position, which is due to a substantial increase of concentration of the reactive anion.
A new bisbenzylisoquinoline alkaloid from Mahonia aquifolium (PURSH) NUTT.
Authors: Košťálová Daniela , Uhrín Dušan , Hrochová Viera , Tomko Jozef
Published: June 2010

Baluchistine and a new phenolic bisbenzylisoquinoline alkaloid aquifoline were isolated from a mixture of tertiary alkaloids from the underground part of Mahonia aquifolium (PURSH) NUTT. On the basis of thin-layer chromatography these compounds also occur in the stem and seeds of the investigated plant.
Heat capacities of six liquid esters as a function of temperature
Authors: Zábranský Milan , Hynek Vladimír , Finkeová-Haštabová Jana , Veselý František
Published: June 2010

Heat capacities along the saturation line have been measured in a recently designed calorimeter from the temperature of 293 K up to the temperature given in parentheses behind the esters measured: methyl formate (298 K), ethyl acetate (340 K), butyl acetate (364 K), methyl propionate (342 K), ethyl propionate (348 K), and propyl propionate (367 K).
Extraction of scandium, cerium, promethium, and europium with dibutylphosphoric, bis(2-ethylhexyl)phosphoric, and dioctylphosphoric acids in Freon 113
Authors: Linhart Petr , Navrátil Oldřich , Havel Josef , Vrchlabský Milan
Published: June 2010

The extraction of Sc, Ce, Pm, and Eu from aqueous solutions of HClO4 and HNO3 into organic phases constituted by solutions of dialkylphosphoric acids in Freon 113 was studied. The effects of the kind of inorganic acid, concentration of hydrogen ions in the aqueous phase and concentration of the extracting agent in the organic phase were examined. Based on the dependences of the distribution ratios of the metals on the above variables, the compositions of the extractable complexes were determined and the extraction constants calculated. The dimerization constants and distribution constants of the monomer were also determined for dibutylphosphoric and bis(2-ethylhexyl)phosphoric acids.
Reversibility of reactions of phenylhydrazonopropanedinitriles with thiols
Authors: Šturdík Ernest , Antalík Marián , Drobnica Ľudovít
Published: June 2010

S-Benzyl (2-phenylhydrazono)cyanothioacetimidate, as a model product of the reactions of phenylhydrazonopropanedinitriles with thiols, is decomposed in physiological medium into the original reactants, i.e. benzyl mercaptan and phenylhydrazonopropanedinitrile. The decomposition rate increases with increasing pH value of the medium. The found reversibility of the reactions of phenylhydrazonopropanedinitriles with thiols is discussed with respect to elucidation of bioactivity of phenylhydrazonopropanedinitriles.
Peptides containing a neopentylglycine residue
Authors: Pospíšek Jan , Bláha Karel
Published: June 2010

Neopentylglycine (III, 2-amino-4,4-dimethylpentanoic acid) was synthesized in both enantiomeric forms. Using the conventional methods of peptide synthesis, L-prolyl-L-neopentylglycylglycine amide (VII), the diastereoisomeric cyclodipeptides cyclo(L-neopentylglycyl-L-prolyl) (IXa) and cyclo(D-neopentylglycyl-L-prolyl) (IXb) and also N-acetyl-L-neopentylglycine methylamide (X) were prepared as models for further studies on physical properties and conformation of peptides.
Mutual relations between excess thermodynamic functions and activity coefficients related to different standard states in systems containing electrolytes and non-electrolytes
Authors: Hála Eduard
Published: June 2010

General relations between excess thermodynamic functions and activity coefficients related to different standard states in systems of electrolytes and non-electrolytes are derived systematically and discussed from the point of view of their chemical-engineering applications.
Simple model of equilibration dynamics of a membrane electrode for determination of CO2
Authors: Lívanský Karel
Published: June 2010

A differential equation is derived describing the course of pH measured by a membrane electrode after a stepwise change in the concentration of CO2 in the measured solution on the assumption that a chemical equilibrium exists between the concentration of CO2 and pH in the solution of hydrogen carbonate forming the inner electrolyte of the membrane electrode. The equation involves chemical equilibrium constants and an adjustable parameter. Calculations were carried out for selected literature data.
Modelling of impregnation of γ-alumina with cobalt and molybdenum salts. Co(NO3)2-(NH4)2MoO4-γ-alumina (chloride type) system
Authors: Hanika Jiří , Janoušek Vladimír , Sporka Karel
Published: June 2010

The kinetics of one-component and two-component impregnation of γ-alumina (prepared from aluminium trichloride) with aqueous solutions of cobalt nitrate and ammonium molybdate were studied and treated in terms of a mathematical model accounting for the simultaneous diffusion and adsorption of the active components. The time-dependent radial concentration profiles of the components across the cylindrical support particle were obtained. The profiles of the cobalt-to-molybdenum atomic ratio were derived from the results. The conclusions are applicable to the development of procedures for the preparation of hydrodesulphuration catalysts for the working of crude oil fractions.
The crystal and electron structure of O-(2-chloroethyl)-O-isobutyl-O-(2-phenyl-4-methylthio-3-oxo-2H-pyridazine-5-yl) thiophosphate
Authors: Vrábel Viktor , Pavelčík František , Kellö Eleonóra , Miertuš Stanislav , Konečný Václav , Lokaj Jan
Published: June 2010

The crystal structure of the title fungicide was solved by direct methods, using Σ2 relationship and tangent formula. The structure refinement was made by full-matrix least-squares with anisotropic temperature factors to the final R = 0.096 for 1 486 significant reflexions. The compound crystallizes in the orthorhombic system, the space group Pccn. The lattice parameters are a = 1.8719(9), b = 3.0426(33), c = 0.7616(2) nm and Z = 8. The intermolecular interactions of types C-H···Cl and C-H···O are observed between the centrosymmetrically related molecules in the crystal structure. The coordination polyhedron around phosphorus is between trigonal pyramid and tetrahedron. The planes of the phenyl and pyridazine rings are rotated through 70° each other. The electron structure was calculated by semiempirical CNDO/2 method. The calculations revealed the most negative net charges on S(2) and O(1). The value of Wiberg index Iw = 1.08 and the bond distance 0.149 nm show that the bond N(1)-C(5) is simple and is not involved in the conjugation.
Reaction of 5-oxo-4-oxahomoadamantane with thionyl chloride
Authors: Janků Josef , Burkhard Jiří , Vodička Luděk
Published: June 2010

On reaction with thionyl chloride 5-oxo-4-oxahomoadamantane gives rise to a mixture of 4a-chloro- and 4e-chloro-2-adamantanone. The carbonyl group of chloroadamantane further reacts with thionyl chloride under formation of 2,2,4e-trichloroadamantane. In the same way adamantanone reacts with thionyl chloride, giving rise to 2,2-dichloroadamantane.