bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ecotypes of Planktonic Actinobacteria with Identical 16S rRNA Genes Adapted to Thermal Niches in Temperate, Subtropical, and Tropical Freshwater Habitats
Authors: Hahn Martin W. , Pöckl Matthias 
Published: February 2005

ABSTRACT

Seven strains with identical 16S rRNA genes affiliated with the Luna2 cluster (
Actinobacteria
) were isolated from six freshwater habitats located in temperate (Austria and Australia), subtropical (People's Republic of China), and tropical (Uganda) climatic zones. The isolates had sequence differences at zero to five positions in a 2,310-nucleotide fragment of the ribosomal operon, including part of the intergenic spacer upstream of the 16S rRNA gene, the complete 16S rRNA gene, the complete 16S-23S internal transcribed spacer (ITS1), and a short part of the 23S rRNA gene. Most of the few sequence differences found were located in the internal transcribed spacer sequences. Two isolates obtained from habitats in Asia and Europe, as well as two isolates obtained from different habitats in the People's Republic of China, had identical sequences for the entire fragment sequenced. In spite of minimal sequence differences in the part of the ribosomal operon investigated, the strains exhibited significant differences in their temperature response curves (with one exception), as well as pronounced differences in their temperature optima (25.0 to 35.6°C). The observed differences in temperature adaptation were generally in accordance with the thermal conditions in the habitats where the strains were isolated. Strains obtained from temperate zone habitats had the lowest temperature optima, strains from subtropical habitats had intermediate temperature optima, and a strain from a tropical habitat had the highest temperature optimum. Based on the observed temperature responses, we concluded that the strains investigated are well adapted to the thermal conditions in their home habitats. Consequently, these closely related strains represent different ecotypes adapted to different thermal niches.
Antimicrobial Action of Carvacrol at Different Stages of Dual-Species Biofilm Development by
Staphylococcus aureus
and
Salmonella enterica
Serovar Typhimurium
Authors: Knowles J. R. , Roller S. , Murray D. B. , Naidu A. S. 
Published: February 2005

ABSTRACT

The effects of carvacrol, a natural biocide, on dual-species biofilms formed by
Staphylococcus aureus
and
Salmonella enterica
serovar Typhimurium were investigated with a constant-depth film fermentor. Biofilm development reached a quasi-steady state in 12 days at 25°C with
S. aureus
predominance (≈99%). Cryosectional analysis detected viable
S. aureus
and
S. enterica
serovar Typhimurium at depths of 320 and 180 μm from the film surface, respectively. Carvacrol pulses (1.0 mmol/h) inhibited
S. aureus
by 2.5 log CFU/biofilm during the early stages of film formation, ultimately causing a significant reduction (
P
< 0.001) of the staphylococcal population at quasi-steady state. Initial carvacrol pulsing elicited a 3 log CFU/biofilm reduction in viable
S. enterica
serovar Typhimurium, and additional periodic carvacrol pulses instigated significant inhibition of salmonellae (1 to 2 log CFU/biofilm) during biofilm development. Carvacrol pulsing reduced protein levels fivefold (
P
< 0.001) during initial biofilm development. Comparative studies with a peroxide-based commercial sanitizer (Spor-Klenz RTU) revealed that this commercial sanitizer was more biocidal than carvacrol during early biofilm development. When the biofilm reached quasi-steady state, however, periodic pulses with 1 mmol of carvacrol per h (
P
= 0.021) elicited a significantly higher inhibition than Spor-Klenz RTU (
P
= 0.772). Dual-species microcolonies formed under the influence of continuously fed low carvacrol concentrations (1.0 mmol/h) but failed to develop into a mature quasi-steady-state biofilm and did not reach any stage of film formation in the presence of high concentrations (5.0 mmol/h). These data show that carvacrol is an effective natural intervention to control dual-species biofilm formation.
New Thermophilic and Thermostable Esterase with Sequence Similarity to the Hormone-Sensitive Lipase Family, Cloned from a Metagenomic Library
Authors: Rhee Jin-Kyu , Ahn Dae-Gyun , Kim Yeon-Gu , Oh Jong-Won 
Published: February 2005

ABSTRACT

A gene coding for a thermostable esterase was isolated by functional screening of
Escherichia coli
cells that had been transformed with fosmid environmental DNA libraries constructed with metagenomes from thermal environmental samples. The gene conferring esterase activity on
E. coli
grown on tributyrin agar was composed of 936 bp, corresponding to 311 amino acid residues with a molecular mass of 34 kDa. The enzyme showed significant amino acid similarity (64%) to the enzyme from a hyperthermophilic archaeon,
Pyrobaculum calidifontis
. An amino acid sequence comparison with other esterases and lipases revealed that the enzyme should be classified as a new member of the hormone-sensitive lipase family. The recombinant esterase that was overexpressed and purified from
E. coli
was active above 30°C up to 95°C and had a high thermal stability. It displayed a high degree of activity in a pH range of 5.5 to 7.5, with an optimal pH of approximately 6.0. The best substrate for the enzyme among the
p
-nitrophenyl esters (C
4
to C
16
) examined was
p
-nitrophenyl caproate (C
6
), and no lipolytic activity was observed with esters containing an acyl chain length of longer than 10 carbon atoms, indicating that the enzyme is an esterase and not a lipase.
Application of the BPEC Pathway for Large-Scale Biotechnological Production of Poly(3-Mercaptopropionate) by Recombinant
Escherichia coli
, Including a Novel In Situ Isolation Method
Authors: Thakor Nehal , Lütke-Eversloh Tina , Steinbüchel Alexander 
Published: February 2005

ABSTRACT

Metabolically engineered
Escherichia coli
JM109 harboring plasmid pBPP1 and expressing the nonnatural BPEC pathway for synthesis of thermoplastic polyhydroxyalkanoates (PHA) and novel polythioesters (PTE) to provide suitable substrates of PHA synthase was investigated with respect to biotechnological production of poly(3-mercaptopropionate) [poly(3MP)]. Fed-batch fermentation processes were established at the 30- and 500-liter scales in stirred tank bioreactors to produce kilogram amounts of poly(3MP). Cultivation was done in a modified M9 mineral salts medium containing glucose or glycerol as the carbon and energy source and with 3-mercaptopropionic acid (3MP) as the precursor substrate for poly(3MP) biosynthesis provided from the late exponential growth phase. Approximately 23 g of cell dry matter (CDM) per liter and poly(3MP) cell contents of up to 45% (wt/wt) were the highest cell densities and polymer contents obtained, respectively. At best, 69.1% (wt/wt) of 3MP was converted into poly(3MP), indicating that 3MP was mostly used for poly(3MP) biosynthesis. Furthermore, a novel in situ process for rapid and convenient isolation of poly(3MP) from the cells in the bioreactor was developed. This was achieved by addition of sodium dodecyl sulfate to the cultivation broth immediately after the fermentation, heating to 90°C for 20 min with intensive stirring, and subsequent washing steps. The purity of such in situ isolated poly(3MP) was more than 98%, as revealed by gas chromatographic and elemental sulfur analyses of the material isolated.
Prevalence of
Salmonella
spp. in Oysters in the United States
Authors: Brands Danielle A. , Inman Allison E. , Gerba Charles P. , Maré C. John , Billington Stephen J. , Saif Linda A. , Levine Jay F. , Joens Lynn A. 
Published: February 2005

ABSTRACT

Food-borne diseases such as salmonellosis can be attributed, in part, to the consumption of raw oysters. To determine the prevalence of
Salmonella
spp. in oysters, oysters harvested from 36 U.S. bays (12 each from the West, East, and Gulf coasts in the summer of 2002, and 12 bays, four per coast, in the winter of 2002-2003) were tested.
Salmonella
was isolated from oysters from each coast of the United States, and 7.4% of all oysters tested contained
Salmonella
. Isolation tended to be bay specific, with some bays having a high prevalence of
Salmonella
, while other bays had none. Differences in the percentage of oysters from which
Salmonella
was isolated were observed between the summer and winter months, with winter numbers much lower probably due to a variety of weather-related events. The vast majority (78/101) of
Salmonella
isolates from oysters were
Salmonella enterica
serovar Newport, a major human pathogen, confirming the human health hazard of raw oyster consumption. Contrary to previous findings, no relationship was found between the isolation of fecal coliforms and
Salmonella
from oysters, indicating a necessity for specific monitoring for
Salmonella
and other pathogens rather than the current reliance on fecal coliform testing.
Disruption of a Cadherin Gene Associated with Resistance to Cry1Ac δ-Endotoxin of
Bacillus thuringiensis
in
Helicoverpa armigera
Authors: Xu Xinjun , Yu Liangying , Wu Yidong 
Published: February 2005

ABSTRACT

A laboratory strain (GY) of
Helicoverpa armigera
(Hübner) was established from surviving larvae collected from transgenic cotton expressing a
Bacillus thuringiensis
var. kurstaki insecticidal protein (Bt cotton) in Gaoyang County, Hebei Province, People's Republic of China, in 2001. The GYBT strain was derived from the GY strain through 28 generations of selection with activated Cry1Ac delivered by diet surface contamination. When resistance to Cry1Ac in the GYBT strain increased to 564-fold after selection, we detected high levels of cross-resistance to Cry1Aa (103-fold) and Cry1Ab (>46-fold) in the GYBT strain with reference to those in the GY strain. The GYBT strain had a low level of cross-resistance to
B. thuringiensis
var. kurstaki formulation (Btk) (5-fold) and no cross-resistance to Cry2Aa (1.4-fold). Genetic analysis showed that Cry1Ac resistance in the GYBT strain was controlled by one autosomal and incompletely recessive gene. The cross-resistance pattern and inheritance mode suggest that the Cry1Ac resistance in the GYBT strain of
H. armigera
belongs to “mode 1,” the most common type of lepidopteran resistance to
B. thuringiensis
toxins. A cadherin gene was cloned and sequenced from both the GY and GYBT strains. Disruption of the cadherin gene by a premature stop codon was associated with a high level of Cry1Ac resistance in
H. armigera
. Tight linkage between Cry1Ac resistance and the cadherin locus was observed in a backcross analysis. Together with previous evidence found with
Heliothis virescens
and
Pectinophora gossypiella
, our results confirmed that the cadherin gene is a preferred target for developing DNA-based monitoring of
B. thuringiensis
resistance in field populations of lepidopteran pests.
Assessment of Elasticity and Topography of
Aspergillus nidulans
Spores via Atomic Force Microscopy
Authors: Zhao Liming , Schaefer David , Marten Mark R. 
Published: February 2005

ABSTRACT

Previous studies have described both surface morphology and adhesive properties of fungal spores, but little information is currently available on their mechanical properties. In this study, atomic force microscopy (AFM) was used to investigate both surface topography and micromechanical properties of
Aspergillus nidulans
spores. To assess the influence of proteins covering the spore surface, wild-type spores were compared with spores from isogenic
rodA

+

and
rodA
−
strains. Tapping-mode AFM images of wild-type and
rodA

+

spores in air showed characteristic “rodlet” protein structures covering a granular spore surface. In comparison,
rodA
−
spores were rodlet free but showed a granular surface structure similar to that of the wild-type and
rodA
+
spores. Rodlets were removed from
rodA

+

spores by sonication, uncovering the underlying granular layer. Both rodlet-covered and rodlet-free spores were subjected to nanoindentation measurements, conducted in air, which showed the stiffnesses to be 110 ± 10, 120 ± 10, and 300 ± 20 N/m and the elastic moduli to be 6.6 ± 0.4, 7.0 ± 0.7, and 22 ± 2 GPa for wild-type,
rodA

+

and
rodA
−
spores, respectively. These results imply the rodlet layer is significantly softer than the underlying portion of the cell wall.
Protozoan
Acanthamoeba polyphaga
as a Potential Reservoir for
Campylobacter jejuni
Authors: Axelsson-Olsson Diana , Waldenström Jonas , Broman Tina , Olsen Björn , Holmberg Martin 
Published: February 2005

ABSTRACT

We showed by a laboratory experiment that four different
Campylobacter jejuni
strains are able to infect the protozoan
Acanthamoeba polyphaga. C. jejuni
cells survived for longer periods when cocultured with amoebae than when grown in culture alone. The infecting
C. jejuni
cells aggregated in amoebic vacuoles, in which they were seen to be actively moving. Furthermore, a resuscitation of bacterial cultures that were previously negative in culturability tests was observed after reinoculation into fresh amoeba cultures. After spontaneous rupture of the amoebae,
C. jejuni
could be detected by microscopy and culturability tests. Our results indicate that amoebae may serve as a nonvertebrate reservoir for
C. jejuni
in the environment.
Temporal trends, gender, and geographic distributions in child and youth injury rates in Sweden
Authors: Ekman R , Svanström L , Långberg B 
Published: February 2005

Objective:Sweden has the lowest child injury mortality rate in the world, 5.2/100 000 for children under 15. This paper describes temporal trends in Sweden, as well as gender related and geographic differences.Design:The Swedish Cause-of-Death Register (1987–2001) and the Hospital Patient Register (1987–2002) were used to compare rates for the country as a whole and for discharges aged 0–20 by municipality, using the SEATS time series analysis program.Results:There was a decrease in the rate offatalunintentional injuries from 7 to 4 per 100 000 for girls and from 16 to 10 per 100 000 for boys since 1987. The gap between girls and boys was reduced and boys now have almost the same mortality rate as girls for violence related deaths. Road and other unintentional injuries show a general decrease whereas the pattern for falls varies by age and sex. Self inflicted injuries increased for both sexes, but more for girls. Substantial differences in injury rates between municipalities were also found—up to six times for girls and eight times for boys.Conclusion:Substantial declines in injury fatalities over time were found, but these were different for boys and girls. There remain substantial differences between municipalities. These data, published in a child injury atlas, have prompted substantial interest among media and the authorities.
Temporal factors in motor vehicle crash deaths
Authors: Farmer C M , Williams A F 
Published: February 2005

Objective:To summarize fatal motor vehicle crash deaths in the United States by time of day, day of week, month, and season, and to determine why some days of the year tend to experience a relatively high number of deaths.Method:Crash deaths were identified and categorized using the Fatality Analysis Reporting System. Days of the year with relatively high crash deaths were compared to the two days that occurred exactly one week before and one week after.Results:On average, motor vehicle crashes in the United States result in more than 100 deaths per day, but there is much day-to-day variability. During 1986–2002 the single day fatality count ranged from a low of 45 to a high of 252. Summer and fall months experience more crash deaths than winter and spring, largely due to increased vehicle travel. July 4 (Independence Day) has more crash deaths on average than any other day of the year, with a relatively high number of deaths involving alcohol. January 1 (New Year’s Day) has more pedestrian crash deaths on average, plus it has the fifth largest number of deaths per day overall, also due to alcohol impairment. On other days the high numbers of deaths are likely due to increases in holiday or recreational travel.Conclusion:Every day of the year results in many crash deaths, but certain days stand out as particularly risky. The temporal and geographic spread of crash deaths, as well as the view of driving as a routine task, inures the public to this continuing problem. Innovative strategies are needed both to raise awareness and to work toward a solution.
Pediatric farm injuries involving non-working children injured by a farm work hazard: five priorities for primary prevention
Authors: Pickett W , Brison R J , Berg R L , Zentner J , Linneman J , Marlenga B 
Published: February 2005

Objectives:To describe pediatric farm injuries experienced by children who were not engaged in farm work, but were injured by a farm work hazard and to identify priorities for primary prevention.Design:Secondary analysis of data from a novel evaluation of an injury control resource using a retrospective case series.Data sources:Fatal, hospitalized, and restricted activity farm injuries from Canada and the United States.Subjects:Three hundred and seventy known non-work childhood injuries from a larger case series of 934 injury events covering the full spectrum of pediatric farm injuries.Methods:Recurrent injury patterns were described by child demographics, external cause of injury, and associated child activities. Factors contributing to pediatric farm injury were described. New priorities for primary prevention were identified.Results:The children involved were mainly resident members of farm families and 233/370 (63.0%) of the children were under the age of 7 years. Leading mechanisms of injury varied by data source but included: bystander and passenger runovers (fatalities); drowning (fatalities); machinery entanglements (hospitalizations); falls from heights (hospitalizations); and animal trauma (hospitalizations, restricted activity injuries). Common activities leading to injury included playing in the worksite (all data sources); being a bystander to or extra rider on farm machinery (all data sources); recreational horseback riding (restricted activity injuries). Five priorities for prevention programs are proposed.Conclusions:Substantial proportions of pediatric farm injuries are experienced by children who are not engaged in farm work. These injuries occur because farm children are often exposed to an occupational worksite with known hazards. Study findings could lead to more refined and focused pediatric farm injury prevention initiatives.
A NEW APPROACH FOR CLASSIFICATION OF GENERIC AUDIO DATA
Authors: LIN RUEI-SHIANG , CHEN LING-HWEI 
Published: February 2005

The existing audio retrieval systems fall into one of two categories: single-domain systems that can accept data of only a single type (e.g. speech) or multiple-domain systems that offer content-based retrieval for multiple types of audio data. Since a single-domain system has limited applications, a multiple-domain system will be more useful. However, different types of audio data will have different properties, this will make a multiple-domain system harder to be developed. If we can classify audio information in advance, the above problems can be solved. In this paper, we will propose a real-time classification method to classify audio signals into several basic audio types such as pure speech, music, song, speech with music background, and speech with environmental noise background. In order to make the proposed method robust for a variety of audio sources, we use Bayesian decision function for multivariable Gaussian distribution instead of manually adjusting a threshold for each discriminator. The proposed approach can be applied to content-based audio/video retrieval. In the experiment, the efficiency and effectiveness of this method are shown by an accuracy rate of more than 96% for general audio data classification.
Changes in ADAMTS13 (von-Willebrand-factor-cleaving protease) activity after induced release of von Willebrand factor during acute systemic inflammation
Authors: Reiter Rosemarie , Varadi Katalin , Turecek Peter , Knöbl Paul , Jilma Bernd 
Published: February 2005

SummaryVon Willebrand factor (VWF) is synthesized in endothelial cells, stored in the form of high molecular weight multimers and released after stimulation. After release, the multimers are cleaved by ADAMTS13 (von-Willebrand-factor-cleaving protease). We studied healthy volunteers in a double-blind, placebo controlled inflammation model. Ten male volunteers received 2 ng/kg endotoxin intravenously, and 5 volunteers placebo. Endotoxin infusion induced systemic inflammation and coagulation activation. After 4 hours the observed increase in neutrophils reached a maximum (273±34 % of baseline; mean ± SEM) and the platelet count dropped (81±2 %). These parameters returned to baseline values after 24 hours. VWF antigen increased to 259±16 % of baseline after 4 hours, remained elevated (192±15 %) after 24 hours and returned to baseline after 7 days. Unusually large VWF multimers occurred in the plasma 4 hours after endotoxin infusion. ADAMTS13 activity (measured with a collagen-binding assay) decreased to 64±5 % of baseline (P< 0.001) after 4 hours, was still reduced after 24 hours (86±6 %; P=0.008) and returned to normal after 7 days. VWF multimer analysis showed pronounced satellite bands in the 4-hour samples, indicating cleavage of VWF by ADAMTS13. No apparent changes of the analyzed parameters were observed in the placebo group. The reciprocal course of ADAMTS13 and VWF after short-term VWF release induced by systemic inflammation is similar to that observed after induction of VWF release by desmopressin.
Gene duplication of coagulation factor V and origin of venom prothrombin activator in Pseudonaja textilis snake
Authors: Minh Le Thi Nguyet , Reza Md Abu , Swarup Sanjay , Kini R. Manjunatha 
Published: February 2005

SummaryThe origin and evolution of venom toxins is a mystery that has evoked much interest. We have recently shown that pseutarin C, a prothrombin activator from Pseudonaja textilis venom, is structurally and functionally similar to mammalian coagulation factor Xa – factor Va complex. Its catalytic subunit is homologous to factor Xa while the nonenzymatic subunit is homologous to factor Va. P.textilis therefore has two parallel prothrombin activator systems: one expressed in its venom gland as a toxin and the other expressed in its liver and released into its plasma as a haemostatic factor. Here we report the complete amino acid sequence of factor V (FV) from its liver determined by cDNA cloning and sequencing. The liver FV shows 96% identity to pseutarin C nonenzymatic subunit. Most of the functional sites involved in its interaction with factor Xa and prothrombin are conserved. However, many potential sites of post-translational modifications and one critical cleavage site for activated protein C are different. The absence of the latter cleavage site makes pseutarin C nonenzymatic subunit resistant to inactivation and enhances its potential as an excellent toxin. By PCR and real-time quantitative analysis, we show that pseutarin C nonenzymatic subunit gene is expressed specifically in the venom gland at ~280 fold higher than that of FV gene in liver. These two are thus encoded by two separate genes that express in a highly tissue-specific manner. Our results imply that the gene encoding pseutarin C nonenzymatic subunit was derived by the duplication of plasma FV gene and they have evolved to perform distinct functions.