bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production and detoxification of H2O2 in lettuce plants exposed to selenium
Authors: Ríos J.J. , Blasco B. , Cervilla L.M. , Rosales M.A. , Sanchez‐Rodriguez E. , Romero L. , Ruiz J.M. 
Published: August 2008

AbstractSelenium is considered an essential element for animals. Despite that it has not been demonstrated to be essential for higher plants, it has been attributed with a protective role against reactive oxygen species in plants subjected to stress. In this study, lettuce plants (Lactuca sativa cv. Philipus) received different application rates (5, 10, 20, 40, 60, 80 and 120 μM) of selenite or selenate, with the aim of testing the effect of Se on the production and detoxification of H2O2 in non‐stressed plants. The results indicate that the form selenate is less toxic than selenite; that is, the plants tolerated and responded positively to this element, and even increasing in growth up to a rate of 40 μM for the form selenate. On the contrary, the application of selenite triggered a higher foliar concentration of H2O2 and a higher induction of lipid peroxidation [malondialdehyde content and lipoxygenase activity] in comparison to that observed after the selenate application. Also, the plants treated with selenate induced higher increases in enzymes that detoxify H2O2, especially ascorbate peroxidase and glutathione (GSH) peroxidase, as well as an increase in the foliar concentration of antioxidant compounds such as ascorbate and GSH. These data indicate that an application of selenate at low rates can be used to prevent the induction in plants of the antioxidant system, thereby improving stress resistance.
Meeting patient needs in the hospital setting— are written nutrition education resources too hard to understand?
Authors: PERKINS Louise , COHEN Jennifer 
Published: August 2008

AbstractAims:  To determine the readability of written nutrition education resources currently used in the Nutrition and Dietetics Department in a large teaching hospital and assess whether these resources are of an appropriate readability level for the target population.Methods:  Dietitians in the department (n = 17) were interviewed to identify resources in use. Readability analysis of current resources (n = 235) followed, using the Simplified Measure of Gobbledegook (SMOG). The SMOG scores were compared with census data for the average reading ability of the target population based on the number of school years completed.Results:  The readability level for the resources ranged from 6 to 15. The mean was 10.4 ± 1.89 (n = 235). This compared with a reading ability in the target population of between years 6 and 8. This discrepancy suggests that the resources may be too complex and are unlikely to be well understood by the target population.Conclusions:  In the time‐poor clinical environment where there is reliance on written nutrition resources to support and reinforce education messages, it is pertinent to pay more attention to readability level. Written resources are unlikely to be effective if they are too complex. It is therefore suggested that dietitians consider the readability when developing and reviewing written nutrition education resources to ensure best‐quality patient care. The results of this project suggest that the SMOG index is a useful method to use for this purpose as it is widely available, easy to use and expedient in implementation.
New Zealand children's dietary intakes during school hours
Authors: REGAN Asher , PARNELL Winsome , GRAY Andrew , WILSON Noela 
Published: August 2008

AbstractAim:  To describe the dietary habits of New Zealand schoolchildren during school hours.Methods:  The present study was a secondary analysis of New Zealand's national nutrition survey of schoolchildren (2002 National Children's Nutrition Survey). It includes a subset of 2247 children aged 5–14 years, surveyed to recall a school day. A 24‐hour dietary recall was collected in the home of the child. Food or beverage consumption during the morning (9:00 a.m.−11:59 a.m.) and at lunch time (12:00 noon−2:00 p.m.) was based on whether energy intake during these times was above zero. Foods consumed and nutrient intakes during these two time periods were ascertained.Results:  Approximately 80% of children consumed some food or beverage during the morning and over 90% during lunch time. Older children were less likely than younger children to consume foods or beverages during lunch time. Snack foods, fruit and biscuits were the food groups most consumed during the morning, while sandwiches and fruit were the most popular foods during lunch time. Children obtained approximately one‐third of their daily nutrient intakes during school hours. Food and nutrient intakes differed by ethnicity both during the morning and at lunch time.Conclusions:  Children's food consumption at school could be improved—particularly morning snack quality. Encouraging healthier selections sourced from home is vital as well as ensuring that healthy options are available for purchase, and Pacific children need the most encouragement to choose wisely.
Modeling
of Convective Cooling of a Rotating Disk by Partially Confined Liquid Jet
Impingement
Authors: Lallave Jorge
C. , Rahman Muhammad
M. 
Published: August 2008

Abstract
This paper presents the results of the numerical simulation of conjugate heat transfer during a semiconfined liquid jet impingement on a uniformly heated spinning solid disk of finite thickness and radius. This study considered various disk materials, namely, aluminum, copper, silver, Constantan, and silicon; covering a range of Reynolds number (220–900), Ekman number (7.08×10−5–∞), nozzle-to-target spacing (β=0.25–1.0), disk thicknesses to nozzle diameter ratio (b∕dn=0.25–1.67), and Prandtl number (1.29–124.44) using ammonia (NH3), water (H2O), flouroinert (FC-77), and oil (MIL-7808) as working fluids. The solid to fluid thermal conductivity ratio was 36.91–2222. A higher thermal conductivity plate material maintained a more uniform interface temperature distribution. A higher Reynolds number increased the local heat transfer coefficient. The rotational rate also increased the local heat transfer coefficient under most conditions.
Influence of Curvature and Pressure Gradient on Turbulent Wake
Development in Curved Channels
Authors: Schobeiri M. T. 
Published: August 2008

Abstract
The development of steady wake flow downstream of a cylindrical rod within a curved channel under the influence of positive, negative, and zero streamwise pressure gradients is theoretically and experimentally investigated. The measured asymmetric wake quantities, such as the mean velocity, turbulent fluctuations in longitudinal and lateral directions, and the turbulent shear stress, are transformed from the probe coordinate system into the curvilinear wake coordinate system. For the transformed nondimensionalized velocity defect and the turbulent quantities, affine profiles are observed throughout the flow regime. Based on the experimental observations and using the transformed equations of motion and continuity, a theoretical framework that generally describes a two-dimensional curvilinear steady wake flow is developed. The theory treats the straight wake flow as a special case for which the curvature radius approaches infinity. A comparison of the developed theory with our own experimental results and with the re-evaluated experimental data from the literature establishes the general validity of the theory.
ABC Transporter Cdr1p Contributes More than Cdr2p Does to Fluconazole Efflux in Fluconazole-Resistant
Candida albicans
Clinical Isolates
Authors: Holmes Ann R. , Lin Ya-Hsun , Niimi Kyoko , Lamping Erwin , Keniya Mikhail , Niimi Masakazu , Tanabe Koichi , Monk Brian C. , Cannon Richard D. 
Published: August 2008

ABSTRACT

Fluconazole (FLC) remains the antifungal drug of choice for non-life-threatening
Candida
infections, but drug-resistant strains have been isolated during long-term therapy with azoles. Drug efflux, mediated by plasma membrane transporters, is a major resistance mechanism, and clinically significant resistance in
Candida albicans
is accompanied by increased transcription of the genes
CDR1
and
CDR2
, encoding plasma membrane ABC-type transporters Cdr1p and Cdr2p. The relative importance of each transporter protein for efflux-mediated resistance in
C. albicans
, however, is unknown; neither the relative amounts of each polypeptide in resistant isolates nor their contributions to efflux function have been determined. We have exploited the pump-specific properties of two antibody preparations, and specific pump inhibitors, to determine the relative expression and functions of Cdr1p and Cdr2p in 18 clinical
C. albicans
isolates. The antibodies and inhibitors were standardized using recombinant
Saccharomyces cerevisiae
strains that hyper-express either protein in a host strain with a reduced endogenous pump background. In all 18
C. albicans
strains, including 13 strains with reduced FLC susceptibilities, Cdr1p was present in greater amounts (2- to 20-fold) than Cdr2p. Compounds that inhibited Cdr1p-mediated function, but had no effect on Cdr2p efflux activity, significantly decreased the resistance to FLC of seven representative
C. albicans
isolates, whereas three other compounds that inhibited both pumps did not cause increased chemosensitization of these strains to FLC. We conclude that Cdr1p expression makes a greater functional contribution than does Cdr2p to FLC resistance in
C. albicans
.
Quantitative Real-Time Reverse Transcription-PCR Analysis Reveals Stable and Prolonged Neurotoxin Cluster Gene Activity in a
Clostridium botulinum
Type E Strain at Refrigeration Temperature
Authors: Chen Ying , Korkeala Hannu , Lindén Jere , Lindström Miia 
Published: August 2008

ABSTRACT

The relative expression levels of six botulinum neurotoxin cluster genes in a group II
Clostridium botulinum
type E strain grown at 10 or 30°C were investigated using quantitative real-time reverse transcription-PCR. An enzyme-linked immunosorbent assay was used to confirm neurotoxin expression. Distinct mRNA and toxin production patterns were observed at the two temperatures. The average relative mRNA levels at 10°C were higher than (
ntnh
and
p47
), similar to (
botE
), or lower than (
orfx1
,
orfx2
,
orfx3
) those at 30°C. The maximum
botE
expression levels and average neurotoxin levels at 10°C were 45 to 65% of those at 30°C. The relative mRNA levels at 10°C declined generally slowly within 8 days, as opposed to the rapid decline observed at 30°C within 24 h. Distinct expression patterns of the six genes at the two temperatures suggest that the type E neurotoxin cluster genes are transcribed as two tricistronic operons at 30°C, whereas at 10°C monocistronic (
botE
or
orfx1
alone) and bicistronic (
ntnh
-
p47
and
orfx2
-
orfx3
) transcription may dominate. Thus, type E botulinum neurotoxin production may be involved with various temperature-dependent regulatory events. In light of group II
C. botulinum
type E being a dangerous food-borne pathogen, these findings may be important in terms of the safety of refrigerated packaged foods of extended durability.
Differential Effects of Temperature on Natural Transformation to Erythromycin and Nalidixic Acid Resistance in
Campylobacter coli
Authors: Kim Joo-Sung , Kim Jae-Won , Kathariou S. 
Published: August 2008

ABSTRACT

Campylobacter jejuni
and
Campylobacter coli
are naturally competent, but limited information exists on the impact of environmental conditions on transformation. In this study, we investigated the impact of temperature and microaerobic versus aerobic atmosphere on transformation of
C. coli
to erythromycin and nalidixic acid resistance. Frequency of transformation was not significantly different between microaerobic (5 to 10% CO
2
) and aerobic conditions. However,
C. coli
was transformed to erythromycin resistance at a significantly higher frequency at 42°C than at 25°C (
P
< 0.05), and few or no transformants were obtained at 25°C. In contrast, transformation to nalidixic acid resistance was highly efficient at both 42°C and 25°C and was similar or, at the most, fourfold higher at 42°C than at 25°C. DNase I treatment experiments suggested that steps both prior and subsequent to internalization of DNA were influenced by temperature in the case of transformation of
C. coli
to erythromycin resistance. However, the moderately increased (fourfold) frequency of transformation to nalidixic acid resistance at 42°C compared to that at 25°C was exclusively associated with steps prior to DNA internalization. These findings suggest that transformation to erythromycin resistance may be significantly more frequent in the gastrointestinal tract of hosts such as poultry (at 42°C) than in other habitats characterized by lower temperatures, whereas transformation to nalidixic acid resistance may be highly efficient both within and outside the animal hosts.
Climate Patterns Governing the Presence and Permanence of Salmonellae in Coastal Areas of Bahia de Todos Santos, Mexico
Authors: Simental Lourdes , Martinez-Urtaza Jaime 
Published: August 2008

ABSTRACT

Despite the importance of salmonellae as one of the major causes of food-borne infections worldwide, data regarding the presence of these organisms in the environment are limited. We investigated the presence of
Salmonella
spp. in Bahia de Todos Santos (Baja California, Mexico) and evaluated the environmental factors that affect the occurrence of
Salmonella
spp. in this arid region. A total of 1,331 samples collected from 21 sites along the coast during a period of 3 years were analyzed for
Salmonella
spp. Geographical and seasonal distribution of
Salmonella
spp. was evaluated in association with environmental parameters and with human infections in the area. The incidence of
Salmonella
bacteria throughout the study was 4.8%, with the highest incidence detected in wastewater (16.2%), followed by stream water (10.6%), mollusks (7.4%), and seawater (2.3%). Twenty different serotypes were identified among the 64
Salmonella
isolates. The dominant serotype was Typhimurium (23.4%), followed by Vejle (6.2%). The presence of
Salmonella
spp. in coastal areas was mostly confined to rainy periods and areas of stream discharges, and runoff was identified as the predominant factor influencing the transport of
Salmonella
bacteria from source points to the sea via streams. Isolation of
Salmonella
spp. was negatively and significantly associated with temperature, probably because of the effect of solar radiation in the decline of permanence of
Salmonella
bacteria. Conversely, human infections prevailed during the warmest months and were negatively correlated with the presence of
Salmonella
spp. in the marine environment.
Amplification of Uncultured Single-Stranded DNA Viruses from Rice Paddy Soil
Authors: Kim Kyoung-Ho , Chang Ho-Won , Nam Young-Do , Roh Seong Woon , Kim Min-Soo , Sung Youlboong , Jeon Che Ok , Oh Hee-Mock , Bae Jin-Woo 
Published: August 2008

ABSTRACT
Viruses are known to be the most numerous biological entities in soil; however, little is known about their diversity in this environment. In order to explore the genetic diversity of soil viruses, we isolated viruses by centrifugation and sequential filtration before performing a metagenomic investigation. We adopted multiple-displacement amplification (MDA), an isothermal whole-genome amplification method with φ29 polymerase and random hexamers, to amplify viral DNA and construct clone libraries for metagenome sequencing. By the MDA method, the diversity of both single-stranded DNA (ssDNA) viruses and double-stranded DNA viruses could be investigated at the same time. On the contrary, by eliminating the denaturing step in the MDA reaction, only ssDNA viral diversity could be explored selectively. Irrespective of the denaturing step, more than 60% of the soil metagenome sequences did not show significant hits (E-value criterion, 0.001) with previously reported viral sequences. Those hits that were considered to be significant were also distantly related to known ssDNA viruses (average amino acid similarity, approximately 34%). Phylogenetic analysis showed that replication-related proteins (which were the most frequently detected proteins) related to those of ssDNA viruses obtained from the metagenomic sequences were diverse and novel. Putative circular genome components of ssDNA viruses that are unrelated to known viruses were assembled from the metagenomic sequences. In conclusion, ssDNA viral diversity in soil is more complex than previously thought. Soil is therefore a rich pool of previously unknown ssDNA viruses.
Syntrophic Growth on Formate: a New Microbial Niche in Anoxic Environments
Authors: Dolfing Jan , Jiang Bo , Henstra Anne M. , Stams Alfons J. M. , Plugge Caroline M. 
Published: August 2008

ABSTRACT

Anaerobic syntrophic associations of fermentative bacteria and methanogenic archaea operate at the thermodynamic limits of life. The interspecies transfer of electrons from formate or hydrogen as a substrate for the methanogens is key. Contrary requirements of syntrophs and methanogens for growth-sustaining product and substrate concentrations keep the formate and hydrogen concentrations low and within a narrow range. Since formate is a direct substrate for methanogens, a niche for microorganisms that grow by the conversion of formate to hydrogen plus bicarbonate—or vice versa—may seem unlikely. Here we report experimental evidence for growth on formate by syntrophic communities of (i)
Moorella
sp. strain AMP in coculture with a thermophilic hydrogen-consuming
Methanothermobacter
species and of (ii)
Desulfovibrio
sp. strain G11 in coculture with a mesophilic hydrogen consumer,
Methanobrevibacter arboriphilus
AZ. In pure culture, neither
Moorella
sp. strain AMP, nor
Desulfovibrio
sp. strain G11, nor the methanogens grow on formate alone. These results imply the existence of a previously unrecognized microbial niche in anoxic environments.
High and Low Temperatures Differently Affect Infection Density and Vertical Transmission of Male-Killing
Spiroplasma
Symbionts in
Drosophila
Hosts
Authors: Anbutsu Hisashi , Goto Shunsuke , Fukatsu Takema 
Published: August 2008

ABSTRACT

We investigated the vertical transmission, reproductive phenotype, and infection density of a male-killing
Spiroplasma
symbiont in two
Drosophila
species under physiological high and low temperatures through successive host generations. In both the native host
Drosophila nebulosa
and the nonnative host
Drosophila melanogaster
, the symbiont infection and the male-killing phenotype were stably maintained at 25°C, rapidly lost at 18°C, and gradually lost at 28°C. In the nonnative host, both the high and low temperatures significantly suppressed the infection density of the spiroplasma. In the native host, by contrast, the low temperature suppressed the infection density of the spiroplasma whereas the high temperature had little effect on the infection density. These results suggested that the low temperature suppresses both the infection density and the vertical transmission of the spiroplasma whereas the high temperature suppresses the vertical transmission preferentially. The spiroplasma density was consistently higher in the native host than in the nonnative host, suggesting that the host genotype may affect the infection density of the symbiont. The temperature- and genotype-dependent instability of the symbiont infection highlights a complex genotype-by-genotype-by-environment interaction and may be relevant to the low infection frequencies of the male-killing spiroplasmas in natural
Drosophila
populations.
Identification of the Putative Protein Phosphatase GenePTC1as a Virulence-Related Gene Using a Silkworm Model ofCandida albicansInfection
Authors: Hanaoka Nozomu , Takano Yukie , Shibuya Kazutoshi , Fugo Hajime , Uehara Yoshimasa , Niimi Masakazu 
Published: August 2008

ABSTRACTProtein phosphatases are critical for the regulation of many cellular processes. Null mutants of 21 putative protein phosphatases ofCandida albicanswere constructed by consecutive allele replacement using theURA3andARG4marker genes. A simple silkworm model ofC. albicansinfection was used to screen the panel of mutants. Four null mutant (cmp1Δ,yvh1Δ,sit4Δ, andptc1Δ) strains showed attenuated virulence in the silkworm model relative to that of control and parental strains. Three of the mutants, thecmp1Δ,yvh1Δ, andsit4Δ mutants, had previously been identified as affecting virulence in a conventional mouse model, indicating the validity of the silkworm model screen. Disruption of the putative protein phosphatase genePTC1ofC. albicans, which has 52% identity to theSaccharomyces cerevisiaetype 2C protein phosphatasePTC1, significantly reduced virulence in the silkworm model. The mutant was also avirulent in a mouse model of disseminated candidiasis. Reintroducing either of theC. albicans PTC1alleles into the disruptant strain, using a cassette containing either allele under the control of a constitutiveACT1promoter, restored virulence in both infection models. Characterization ofptc1Δ revealed other phenotypic traits, including reduced hyphal growth in vitro and in vivo, and reduced extracellular proteolytic activity. We conclude thatPTC1may contribute to pathogenicity inC. albicans.
Anoxia-Induced Suspended Animation in Budding Yeast as an Experimental Paradigm for Studying Oxygen-Regulated Gene Expression
Authors: Chan Kin , Roth Mark B. 
Published: August 2008

ABSTRACT

A lack of oxygen can force many organisms to enter into recoverable hypometabolic states. To better understand how organisms cope with oxygen deprivation, our laboratory previously had shown that when challenged with anoxia, both the nematode
Caenorhabditis elegans
and embryos of the zebrafish
Danio rerio
enter into suspended animation, in which all life processes that can be observed by light microscopy reversibly halt pending the restoration of oxygen (P. A. Padilla and M. B. Roth, Proc. Natl. Acad. Sci. USA 98:7331-7335, 2001, and P. A. Padilla, T. G. Nystul, R. A. Zager, A. C. Johnson, and M. B. Roth, Mol. Biol. Cell 13:1473-1483, 2002). Here, we show that both sporulating and vegetative cells of the budding yeast
Saccharomyces cerevisiae
also enter into a similar state of suspended animation when made anoxic on a nonfermentable carbon source. Transcriptional profiling using cDNA microarrays and follow-on quantitative real-time PCR analysis revealed a relative derepression of aerobic metabolism genes in carbon monoxide (CO)-induced anoxia when compared to nitrogen (N
2
) gas-induced anoxia, which is consistent with the known oxygen-mimetic effects of CO. We also found that mutants deleted for components of the mitochondrial retrograde signaling pathway can tolerate prolonged exposure to CO but not to N
2
. We conclude that the cellular response to anoxia is dependent on whether the anoxic gas is an oxygen mimetic and that the mitochondrial retrograde signaling pathway is functionally important for mediating this response.