bluuebunny/crossref_metadata_2025_split huggingface dataset:
Daily physical activity in Swedish children aged 8–11 years
Authors: Dencker M. , Thorsson O. , Karlsson M. K. , Lindén C. , Svensson J. , Wollmer P. , Andersen L. B. 
Published: October 2005

Introduction: Physical inactivity is hypothesized to be a contributing factor in the development of a variety of diseases. Recommendations for an adequate level of physical activity have been proposed. There are few studies in which the physical activity in children has been objectively assessed. The purpose of this study was to estimate objectively the level of physical activity in Swedish children.Materials and methods: We studied 248 children (140 boys and 108 girls) aged 7.9–11.1 years from Malmö, Sweden. Physical activity was measured with accelerometers. Children were instructed to wear the accelerometers for 4 days. The mean daily activity was expressed as the mean counts per minute of recording. The time that the child spent performing moderate or vigorous activity was calculated by using previously established cutoff points.Results: The mean daily activity was higher in boys than in girls, 751±243 vs 618±154 counts/min (P<0.001). All children fulfilled the recommendation for moderate physical activity for 60 min or more per day. Ninety‐two percent of the boys and 86% of the girls performed vigorous activity, for 20 min or more per day.Conclusion: All children, aged 8–11 years, who participated in this study reached the recommended level of physical activity, with boys being more active than girls.
Pumping Test in a Confined Aquifer Under Tidal Influence
Authors: Chapuis Robert P. , Bélanger Christian , Chenaf Djaouida 
Published: October 2005

AbstractIn a coastal environment, tide‐induced head fluctuations can complicate the interpretation of drawdown data from pumping tests. For confined aquifers and sinusoidal tides, the superposition principle can be used to obtain a closed‐form solution. After subtracting the net tidal effects, the drawdown data become amenable to the standard analyses. Numerical simulations have shown that the method is reliable when the distance of the monitoring well to the well does not exceed 10% of the distance between the well and the tidal boundary.
Direct Labeling of Polyphosphate at the Ultrastructural Level inSaccharomyces cerevisiaeby Using the Affinity of the Polyphosphate Binding Domain ofEscherichia coliExopolyphosphatase
Authors: Saito Katsuharu , Ohtomo Ryo , Kuga-Uetake Yukari , Aono Toshihiro , Saito Masanori 
Published: October 2005

ABSTRACTInorganic polyphosphate (polyP) is a linear polymer of orthophosphate and has many biological functions in prokaryotic and eukaryotic organisms. To investigate polyP localization, we developed a novel technique using the affinity of the recombinant polyphosphate binding domain (PPBD) ofEscherichia coliexopolyphosphatase to polyP. An epitope-tagged PPBD was expressed and purified fromE. coli. Equilibrium binding assay of PPBD revealed its high affinity for long-chain polyP and its weak affinity for short-chain polyP and nucleic acids. To directly demonstrate polyP localization inSaccharomyces cerevisiaeon resin sections prepared by rapid freezing and freeze-substitution, specimens were labeled with PPBD containing an epitope tag and then the epitope tag was detected by an indirect immunocytochemical method. A goat anti-mouse immunoglobulin G antibody conjugated with Alexa 488 for laser confocal microscopy or with colloidal gold for transmission electron microscopy was used. When theS. cerevisiaewas cultured in yeast extract-peptone-dextrose medium (10 mM phosphate) for 10 h, polyP was distributed in a dispersed fashion in vacuoles in successfully cryofixed cells. A few polyP signals of the labeling were sometimes observed in cytosol around vacuoles with electron microscopy. Under our experimental conditions, polyP granules were not observed. Therefore, it remains unclear whether the method can detect the granule form. The method directly demonstrated the localization of polyP at the electron microscopic level for the first time and enabled the visualization of polyP localization with much higher specificity and resolution than with other conventional methods.
Metabolic Engineering of the Purine Pathway for Riboflavin Production in
Ashbya gossypii
Authors: Jiménez Alberto , Santos María A. , Pompejus Markus , Revuelta José L. 
Published: October 2005

ABSTRACT

Purine nucleotides are essential precursors for living organisms because they are involved in many important processes, such as nucleic acid synthesis, energy supply, and the biosynthesis of several amino acids and vitamins such as riboflavin. GTP is the immediate precursor for riboflavin biosynthesis, and its formation through the purine pathway is subject to several regulatory mechanisms in different steps. Extracellular purines repress the transcription of most genes required for de novo ATP and GTP synthesis. Additionally, three enzymes of the pathway, phosphoribosyl pyrophosphate (PRPP) amidotransferase, adenylosuccinate synthetase, and IMP dehydrogenase, are subject to feedback inhibition by their end products. Here we report the characterization and manipulation of the committed step in the purine pathway of the riboflavin overproducer
Ashbya gossypii
. We report that phosphoribosylamine biosynthesis in
A. gossypii
is negatively regulated at the transcriptional level by extracellular adenine. Furthermore, we show that ATP and GTP exert a strong inhibitory effect on the PRPP amidotransferase from
A. gossypii
. We constitutively overexpressed the Ag
ADE4
gene encoding PRPP amidotransferase in
A. gossypii
, thereby abolishing the adenine-mediated transcriptional repression. In addition, we replaced the corresponding residues (aspartic acid
310
, lysine
333
, and alanine
417
) that have been described to be important for PRPP amidotransferase feedback inhibition in other organisms by site-directed mutagenesis. With these manipulations, we managed to enhance metabolic flow through the purine pathway and to increase the production of riboflavin in the triple mutant strain 10-fold (228 mg/liter).
Long-Term Survival of Pathogenic and Sanitation Indicator Bacteria in Experimental Biowaste Composts
Authors: Lemunier Mélanie , Francou Cédric , Rousseaux Sandrine , Houot Sabine , Dantigny Philippe , Piveteau Pascal , Guzzo Jean 
Published: October 2005

ABSTRACT

For economic, agricultural, and environmental reasons, composting is frequently used for organic waste recycling. One approach to limiting the potential risk from bacterial food-borne illnesses is to ensure that soil amendments and organic fertilizers are disinfected. However, more knowledge concerning the microbiological safety of composted substrates other than sludge and manure is necessary. Experimental in-vessel biowaste composts were used to study the survival of seeded
Listeria monocytogenes
,
Salmonella enterica
subsp.
enterica
serotype Enteritidis, and
Escherichia coli
. Four organic waste mixtures, containing various proportions of paper and cardboard, fruits and vegetables, and green waste, were composted in laboratory reactors with forced aeration. The physicochemical and microbiological parameters were monitored for 12 weeks during composting. The survival of bacteria over a 3-month period at 25°C was assessed with samples collected after different experimental composting times. Strain survival was also monitored in mature sterilized composts. Nonsterile composts did not support pathogen growth, but survival of seeded pathogens was observed.
Salmonella
serovar Enteritidis survived in all composts, and longer survival (3 months) was observed in mature composts (8 and 12 weeks of composting). Mature biowaste composts may support long-term survival of
Salmonella
serovar Enteritidis during storage at room temperature.
E. coli
and
L. monocytogenes
survival was observed only in 4-week-old composts and never in older composts. Proper composting may prevent long-term survival of
E. coli
and
L. monocytogenes
. These results suggest that like composted sewage sludge or manure, domestic waste composts may support pathogen survival. Survival was not related to the physicochemical characteristics of the composts.
Use of Random and Saturation Mutageneses To Improve the Properties of
Thermus aquaticus
Amylomaltase for Efficient Production of Cycloamyloses
Authors: Fujii Kazutoshi , Minagawa Hirotaka , Terada Yoshinobu , Takaha Takeshi , Kuriki Takashi , Shimada Jiro , Kaneko Hiroki 
Published: October 2005

ABSTRACT

Amylomaltase from
Thermus aquaticus
catalyzes intramolecular transglycosylation of α-1,4 glucans to produce cyclic α-1,4 glucans (cycloamyloses) with degrees of polymerization of 22 and higher. Although the amylomaltase mainly catalyzes the transglycosylation reaction, it also has weak hydrolytic activity, which results in a reduction in the yield of the cycloamyloses. In order to obtain amylomaltase with less hydrolytic activity, random mutagenesis was perfromed for the enzyme gene. Tyr54 (Y54) was identified as the amino acid involved in the hydrolytic activity of the enzyme. When Y54 was replaced with all other amino acids by site-directed mutagenesis, the hydrolytic activities of the mutated enzymes were drastically altered. The hydrolytic activities of the Y54G, Y54P, Y54T, and Y54W mutated enzymes were remarkably reduced compared with that of the wild-type enzyme, while those of the Y54F and Y54K mutated enzymes were similar to that of the wild-type enzyme. Introducing an amino acid replacement at Y54 also significantly affected the cyclization activity of the amylomaltase. The Y54A, Y54L, Y54R, and Y54S mutated enzymes exhibited cyclization activity that was approximately twofold higher than that of the wild-type enzyme. When the Y54G mutated enzyme was employed for cycloamylose production, the yield of cycloamyloses was more than 90%, and there was no decrease until the end of the reaction.
Concentrations of Pathogens and Indicators in Animal Feces in the Sydney Watershed
Authors: Cox Peter , Griffith Merran , Angles Mark , Deere Daniel , Ferguson Christobel 
Published: October 2005

ABSTRACTA fecal analysis survey was undertaken to quantify animal inputs of pathogenic and indicator microorganisms in the temperate watersheds of Sydney, Australia. The feces from a range of domestic animals and wildlife were analyzed for the indicator bacteria fecal coliforms andClostridium perfringensspores, the pathogenic protozoaCryptosporidiumandGiardia, and the enteric viruses adenovirus, enterovirus, and reovirus. Pathogen and fecal indicator concentrations were generally higher in domestic animal feces than in wildlife feces. Future studies to quantify potential pathogen risks in drinking-water watersheds should thus focus on quantifying pathogen loads from domestic animals and livestock rather than wildlife.
Factors Associated with the Presence of Coliforms in the Feed and Water of Feedlot Cattle
Authors: Sanderson Michael W. , Sargeant Jan M. , Renter David G. , Griffin D. Dee , Smith Robert A. 
Published: October 2005

ABSTRACT

The objective of this study was to investigate coliform counts in feedlot cattle water and feed rations and their associations with management, climate, fecal material, and water
Escherichia coli
O157 using a cross-sectional study design. Coliform counts were performed on feed samples from 671 pens on 70 feedlots and on water samples from 702 pens on 72 feedlots in four U.S. states collected between May and August 2001. Management and climate factors were obtained by survey and observation. Month of sampling (higher in May and June), presence of corn silage in the ration (negative association), temperature of the feed 1 in. (ca. 2.5 cm) below the surface at the time of sampling (negative association), and wind velocity at the time of sampling (positive association) were significantly associated with log
10
coliform levels in feed. Month of sampling (lower in May versus June July and August), water pH (negative association), and water total solids (positive association) were significantly associated with log
10
water coliform levels. Coliform counts in feed and water were not associated with prevalence of
E. coli
O157 in cattle feces or water. Management risk factors must be interpreted with caution but the results reported here do not support the use of coliform counts as a marker for
E. coli
O157 contamination of feed or water.
Detection and Characterization of
Streptococcus thermophilus
Bacteriophages by Use of the Antireceptor Gene Sequence
Authors: Binetti Ana G. , Del Río Beatriz , Martín M. Cruz , Álvarez Miguel A. 
Published: October 2005

ABSTRACT

In the dairy industry, the characterization of
Streptococcus thermophilus
phage types is very important for the selection and use of efficient starter cultures. The aim of this study was to develop a characterization system useful in phage control programs in dairy plants. A comparative study of phages of different origins was initially performed based on their morphology, DNA restriction profiles, DNA homology, structural proteins, packaging mechanisms, and lifestyles and on the presence of a highly conserved DNA fragment of the replication module. However, these traditional criteria were of limited industrial value, mainly because there appeared to be no correlation between these variables and host ranges. We therefore developed a PCR method to amplify VR2, a variable region of the antireceptor gene, which allowed rapid detection of
S. thermophilus
phages and classification of these phages. This method has a significant advantage over other grouping criteria since our results suggest that there is a correlation between typing profiles and host ranges. This association could be valuable for the dairy industry by allowing a rational starter rotation system to be established and by helping in the selection of more suitable starter culture resistance mechanisms. The method described here is also a useful tool for phage detection, since specific PCR amplification was possible when phage-contaminated milk was used as a template (detection limit, 10
5
PFU ml
−1
).
Role of thessuandseuGenes ofCorynebacterium glutamicumATCC 13032 in Utilization of Sulfonates and Sulfonate Esters as Sulfur Sources
Authors: Koch D. J. , Rückert C. , Rey D. A. , Mix A. , Pühler A. , Kalinowski J. 
Published: October 2005

ABSTRACTCorynebacterium glutamicumATCC 13032 was found to be able to utilize a broad range of sulfonates and sulfonate esters as sulfur sources. The two gene clusters potentially involved in sulfonate utilization,ssuD1CBAandssuI-seuABC-ssuD2, were identified in the genome ofC. glutamicumATCC 13032 by similarity searches. While thessugenes encode proteins resembling Ssu proteins fromEscherichia coliorBacillus subtilis, theseugene products exhibited similarity to the dibenzothiophene-degrading Dsz monooxygenases ofRhodococcusstrain IGTS8. Growth tests with theC. glutamicumwild-type and appropriate mutant strains showed that the clustered genesssuC,ssuB, andssuA, putatively encoding the components of an ABC-type transporter system, are required for the utilization of aliphatic sulfonates. InC. glutamicumsulfonates are apparently degraded by sulfonatases encoded byssuD1andssuD2. It was also found that theseugenesseuA,seuB, andseuCcan effectively replacessuD1andssuD2for the degradation of sulfonate esters. The utilization of all sulfonates and sulfonate esters tested is dependent on a novel putative reductase encoded byssuI. Obviously, all monooxygenases encoded by thessuandseugenes, including SsuD1, SsuD2, SeuA, SeuB, and SeuC, which are reduced flavin mononucleotide dependent according to sequence similarity, have SsuI as an essential component. Using real-time reverse transcription-PCR, thessuandseugene cluster was found to be expressed considerably more strongly during growth on sulfonates and sulfonate esters than during growth on sulfate.
Genetic Variation of the Bloom-Forming CyanobacteriumMicrocystis aeruginosawithin and among Lakes: Implications for Harmful Algal Blooms
Authors: Wilson Alan E. , Sarnelle Orlando , Neilan Brett A. , Salmon Tim P. , Gehringer Michelle M. , Hay Mark E. 
Published: October 2005

ABSTRACTTo measure genetic variation within and among populations of the bloom-forming cyanobacteriumMicrocystis aeruginosa, we surveyed a suite of lakes in the southern peninsula of Michigan that vary in productivity (total phosphorus concentrations of ∼10 to 100 μg liter−1). Survival ofM. aeruginosaisolates from lakes was relatively low (i.e., mean of 7% and maximum of 30%) and positively related to lake total phosphorus concentration (P= 0.014,r2= 0.407,n= 14). In another study (D. F. Raikow, O. Sarnelle, A. E. Wilson, and S. K. Hamilton, Limnol. Oceanogr. 49:482-487, 2004), survival rates ofM. aeruginosaisolates collected from an oligotrophic lake (total phosphorus of ∼10 μg liter−1and dissolved inorganic nitrogen:total phosphorus ratio of 12.75) differed among five different medium types (Gtest,Pof <0.001), with higher survival (P= 0.003) in low-nutrient media (28 to 37% survival) than in high-nutrient media. Even with the relatively low isolate survivorship that could select against detecting the full range of genetic variation, populations ofM. aeruginosawere genetically diverse within and among lakes (by analysis of molecular variance, Φsc= 0.412 [Φscis an F-statistic derivative which evaluates the correlation of haplotypic diversity within populations relative to the haplotypic diversity among all sampled populations],P= 0.001), with most clones being distantly related to clones collected from lakes directly attached to Lake Michigan (a Laurentian Great Lake) and culture collection strains collected from Canada, Scotland, and South Africa. Ninety-one percent of the 53 genetically uniqueM. aeruginosaclones contained the microcystin toxin gene (mcyA). Genotypes with the toxin gene were found in all lakes, while four lakes harbored both genotypes possessing and genotypes lacking the toxin gene.
Survival or Growth of
Escherichia coli
O157:H7 in a Model System of Fresh Meat Decontamination Runoff Waste Fluids and Its Resistance to Subsequent Lactic Acid Stress
Authors: Samelis John , Sofos John N. , Kendall Patricia A. , Smith Gary C. 
Published: October 2005

ABSTRACT

A potential may exist for survival of and resistance development by
Escherichia coli
O157:H7 in environmental niches of meat plants applying carcass decontamination interventions. This study evaluated (i) survival or growth of acid-adapted and nonadapted
E. coli
O157:H7 strain ATCC 43895 in acetic acid (pH 3.6 ± 0.1) or in water (pH 7.2 ± 0.2) fresh beef decontamination runoff fluids (washings) stored at 4, 10, 15, or 25°C and (ii) resistance of cells recovered from the washings after 2 or 7 days of storage to a subsequent lactic acid (pH 3.5) stress. Corresponding cultures in sterile saline or in heat-sterilized water washings were used as controls. In acetic acid washings, acid-adapted cultures survived better than nonadapted cultures, with survival being greatest at 4°C and lowest at 25°C. The pathogen survived without growth in water washings at 4 and 10°C, while it grew by 0.8 to 2.7 log cycles at 15 and 25°C, and more in the absence of natural flora.
E. coli
O157:H7 cells habituated without growth in water washings at 4 or 10°C were the most sensitive to pH 3.5, while cells grown in water washings at 15 or 25°C were relatively the most resistant, irrespective of previous acid adaptation. Resistance to pH 3.5 of
E. coli
O157:H7 cells habituated in acetic acid washings for 7 days increased in the order 15°C > 10°C > 4°C, while at 25°C cells died off. These results indicate that growth inhibition by storage at low temperatures may be more important than competition by natural flora in inducing acid sensitization of
E. coli
O157:H7 in fresh meat environments. At ambient temperatures in meat plants,
E. coli
O157:H7 may grow to restore acid resistance, unless acid interventions are applied to inhibit growth and minimize survival of the pathogen. Acid-habituated
E. coli
O157:H7 at 10 to 15°C may maintain a higher acid resistance than when acid habituated at 4°C. These responses should be evaluated with fresh meat and may be useful for the optimization of decontamination programs and postdecontamination conditions of meat handling.
Electrochemical Polarization-Induced Changes in the Growth of Individual Cells and Biofilms of
Pseudomonas fluorescens
(ATCC 17552)
Authors: Busalmen Juan Pablo , de Sánchez Susana R. 
Published: October 2005

ABSTRACT

The effect of surface electrochemical polarization on the growth of cells of
Pseudomonas fluorescens
(ATCC 17552) on gold electrodes has been examined. Potentials positive or negative to the potential of zero charge (PZC) of gold were applied, and these resulted in changes in cell morphology, size at cell division, time to division, and biofilm structure. At −0.2 V (Ag/AgCl-3 M NaCl), cells elongated at a rate of up to 0.19 μm min
−1
, rendering daughter cells that reached up to 3.8 μm immediately after division. The doubling time for the entire population, estimated from the increment in the fraction of surface covered by bacteria, was 82 ± 7 min. Eight-hour-old biofilms at −0.2 V were composed of large cells distributed in expanded mushroom-like microcolonies that protruded several micrometers in the solution. A different behavior was observed under positive polarization. At an applied potential of 0.5 V, the doubling time of the population was 103 ± 8 min, cells elongated at a lower rate (up to 0.08 μm min
−1
), rendering shorter daughters (2.5 ± 0.5 μm) after division, although the duplication times were virtually the same at all potentials. Biofilms grown under this positive potential were composed of short cells distributed in a large number of compact microcolonies. These were flatter than those grown at −0.2 V or at the PZC and were pyramidal in shape. Polarization effects on cell growth and biofilm structure resembled those previously reported as produced by changes in the nutritional level of the culture medium.
Diversity and Distribution of Sulfate-Reducing Bacteria in Permanently Frozen Lake Fryxell, McMurdo Dry Valleys, Antarctica
Authors: Karr Elizabeth A. , Sattley W. Matthew , Rice Melissa R. , Jung Deborah O. , Madigan Michael T. , Achenbach Laurie A. 
Published: October 2005

ABSTRACTThe permanently frozen freshwater Lake Fryxell, located in the Dry Valleys of Antarctica, exhibits an ideal geochemistry for microbial sulfate reduction. To investigate the population of sulfate-reducing bacteria in Lake Fryxell, both 16S rRNA gene and metabolic primer sets targeting thedsrAgene for the dissimilatory sulfite reductase alpha subunit were employed to analyze environmental DNA obtained from the water column and sediments of Lake Fryxell. In addition, enrichment cultures of sulfate-reducing bacteria established at 4°C from Lake Fryxell water were also screened using thedsrAprimer set. The sequence information obtained showed that a diverse group of sulfate-reducing prokaryotes of the domainBacteriainhabit Lake Fryxell. With one exception, the enrichment culture sequences were not represented within the environmental sequences. Sequence data were compared with the geochemical profile of Lake Fryxell to identify possible connections between the diversity of sulfate-reducing bacteria and limnological conditions. Several clone groups were highly localized with respect to lake depth and, therefore, experienced specific physiochemical conditions. However, all sulfate-reducing bacteria inhabiting Lake Fryxell must function under the constantly cold conditions characteristic of this extreme environment.
Deletion of the
sigB
Gene in
Bacillus cereus
ATCC 14579 Leads to Hydrogen Peroxide Hyperresistance
Authors: van Schaik Willem , Zwietering Marcel H. , de Vos Willem M. , Abee Tjakko 
Published: October 2005

ABSTRACT

The
sigB
gene of
Bacillus cereus
ATCC 14579 encodes the alternative sigma factor σ
B
. Deletion of
sigB
in
B. cereus
leads to hyperresistance to hydrogen peroxide. The expression of
katA
, which encodes one of the catalases of
B. cereus
, is upregulated in the
sigB
deletion mutant, and this may contribute to the hydrogen peroxide-resistant phenotype.