bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Discontinued Obstetrical Services in Rural Missouri: 1990‐2002
Authors: Sontheimer Dan , Halverson Larry W. , Bell Laird , Ellis Mark , Bunting Pamela Wilbanks 
Published: February 2008

ABSTRACT:
Purpose:

This study examines the potential relationship between loss of local obstetrical services and pregnancy outcomes.

Methods:

Missouri Hospital Association and Missouri Department of Health birth certificate records were used as sources of information. All member hospitals of the Missouri Hospital Association that were located in cities of 10,000 or less were identified and surveyed by telephone.

Results:

Frequency of low birth weight babies originating from service areas where hospitals closed services was statistically increased in the first year after service closures. This effect was transient.

Conclusions:

Transient increases in the rate of lower birth weights may reveal difficulties in service access after closure. These outcomes merit further investigation into the consequences of disruptions in access to maternity care in rural communities.
Migrant Farmworker Stress: Mental Health Implications
Authors: Hiott Ann E. , Grzywacz Joseph G. , Davis Stephen W. , Quandt Sara A. , Arcury Thomas A. 
Published: February 2008

ABSTRACT:
Context:

The number of Latinos in rural regions of the United States is increasing. Little is known about factors that undermine the mental health of this segment of the rural population. Purpose: The goal of this study is to determine which stressors inherent in farmwork and the farmworker lifestyle contribute to poor mental health. Methods: An interview containing the Migrant Farmworker Stress Inventory (MFWSI) and 3 mental health scales (the PAI [anxiety], CES‐D [depression], and CAGE/4M [alcohol abuse]) was administered to a sample of 125 male migrant farmworkers. Factor analysis differentiated discrete domains of stressors in the MFWSI. Regression models identified associations of the MFWSI stressor domains with mental health outcomes. Findings: Thirty‐eight percent of participants had significant levels of stress as determined by the MFWSI. The MFWSI reduced to 5 stressor domains: legality and logistics, social isolation, work conditions, family, and substance abuse by others. Some 18.4% of participants had impairing levels of anxiety, 41.6% met caseness for depression, and 37.6% answered yes to 2 or more questions on the CAGE. Social isolation and working conditions were associated with both anxiety and depressive symptoms. However, social isolation was more strongly associated with anxiety, and working conditions were more strongly linked to depression. Conclusions: Specific categories of stressors (social isolation, working conditions) inherent in farmwork and the farmworker lifestyle are associated with mental health among immigrant farmworkers. Isolating specific categories of stressors helps in designing programs and practice for the prevention and management of mental health disorders in the immigrant, farmworker population.
Cultural Perspectives Concerning Adolescent Use of Tobacco and Alcohol in the Appalachian Mountain Region
Authors: Meyer Michael G. , Toborg Mary A. , Denham Sharon A. , Mande Mary J. 
Published: February 2008

ABSTRACT:
Context:

Appalachia has high rates of tobacco use and related health problems, and despite significant impediments to alcohol use, alcohol abuse is common. Adolescents are exposed to sophisticated tobacco and alcohol advertising. Prevention messages, therefore, should reflect research concerning culturally influenced attitudes toward tobacco and alcohol use. Methods: With 4 grants from the National Institutes of Health, 34 focus groups occurred between 1999 and 2003 in 17 rural Appalachian jurisdictions in 7 states. These jurisdictions ranged between 4 and 8 on the Rural‐Urban Continuum Codes of the Economic Research Service of the US Department of Agriculture. Of the focus groups, 25 sought the perspectives of women in Appalachia, and 9, opinions of adolescents. Findings: The family represented the key context where residents of Appalachia learn about tobacco and alcohol use. Experimentation with tobacco and alcohol frequently commenced by early adolescence and initially occurred in the context of the family home. Reasons to abstain from tobacco and alcohol included a variety of reasons related to family circumstances. Adults generally displayed a greater degree of tolerance for adolescent alcohol use than tobacco use. Tobacco growing represents an economic mainstay in many communities, a fact that contributes to the acceptance of its use, and many coal miners use smokeless tobacco since they cannot light up in the mines. The production and distribution of homemade alcohol was not a significant issue in alcohol use in the mountains even though it appeared not to have entirely disappeared. Conclusions: Though cultural factors support tobacco and alcohol use in Appalachia, risk awareness is common. Messages tailored to cultural themes may decrease prevalence.
Appalachian Women's Perceptions of Their Community's Health Threats
Authors: Schoenberg Nancy E. , Hatcher Jennifer , Dignan Mark B. 
Published: February 2008

ABSTRACT:
Context:

Decades of behavioral research suggest that awareness of health threats is a necessary precursor to engage in health promotion and disease prevention, findings that can be extended to the community level. Purpose: We sought to better understand local perspectives on the main health concerns of rural Appalachian communities in order to identify the key health priorities. While Kentucky Appalachian communities are often described as suffering from substandard health, resource, and socioeconomic indicators, strong traditions of community mobilization make possible positive, home‐grown change. Methods: To assess what women, the key health gatekeepers, perceive as the most significant health threats to their rural communities, 10 focus groups were held with 52 Appalachian women from diverse socioeconomic backgrounds. Tape‐recorded narratives were content analyzed and a codebook was developed. Measures designed to increase data trustworthiness included member checks, negative case evidence, and multiple coding. Findings: The following rank‐ordered conditions emerged as posing the greatest threat to the health of rural Appalachian communities: (1) drug abuse/medication dependence; (2) cancer; (3) heart disease and diabetes (tied); (4) smoking; (5) poor diet/overweight; (6) lack of exercise; and (7) communicable diseases. These health threats were described as specific to the local environment, deriving from broad ecological problems and were connected to one another. Conclusion: Drawing on participants' community‐relevant suggestions, we suggest ways in which rural communities may begin to confront these health concerns. These suggestions range from modest, individual‐level changes to broader structural‐level recommendations.
Metabolic regulation and overproduction of primary metabolites
Authors: Sanchez Sergio , Demain Arnold L. 
Published: February 2008

SummaryOverproduction of microbial metabolites is related to developmental phases of microorganisms. Inducers, effectors, inhibitors and various signal molecules play a role in different types of overproduction. Biosynthesis of enzymes catalysing metabolic reactions in microbial cells is controlled by well‐known positive and negative mechanisms, e.g. induction, nutritional regulation (carbon or nitrogen source regulation), feedback regulation, etc. The microbial production of primary metabolites contributes significantly to the quality of life. Fermentative production of these compounds is still an important goal of modern biotechnology. Through fermentation, microorganisms growing on inexpensive carbon and nitrogen sources produce valuable products such as amino acids, nucleotides, organic acids and vitamins which can be added to food to enhance its flavour, or increase its nutritive values. The contribution of microorganisms goes well beyond the food and health industries with the renewed interest in solvent fermentations. Microorganisms have the potential to provide many petroleum‐derived products as well as the ethanol necessary for liquid fuel. Additional applications of primary metabolites lie in their impact as precursors of many pharmaceutical compounds. The roles of primary metabolites and the microbes which produce them will certainly increase in importance as time goes on. In the early years of fermentation processes, development of producing strains initially depended on classical strain breeding involving repeated random mutations, each followed by screening or selection. More recently, methods of molecular genetics have been used for the overproduction of primary metabolic products. The development of modern tools of molecular biology enabled more rational approaches for strain improvement. Techniques of transcriptome, proteome and metabolome analysis, as well as metabolic flux analysis. have recently been introduced in order to identify new and important target genes and to quantify metabolic activities necessary for further strain improvement.
Old Paths and New Directions: Studying Emotions in the Workplace
Authors: Meanwell Emily , Wolfe Joseph D. , Hallett Tim 
Published: February 2008

AbstractThe study of emotions in the workplace is a vibrant area of research that has grown considerably over the last 25 years. This research has traveled far, but it has not run its course. This article maps the different paths that have been explored, beginning with Hochschild's classic work on emotional labor in the form of surface and deep acting, and charts new directions for future research. We start by reviewing the literature on emotional labor and emotion management in the workplace. Next, we discuss new theoretical developments in the sociology of emotions – interaction ritual chain theory, theories of identity and affect control, and theories about power, status, and exchange – and their potential utility for understanding emotions at work. Finally, we discuss new methodological directions that can be pursued in future research on emotions in work and organizational settings.
Packaging of Live
Legionella pneumophila
into Pellets Expelled by
Tetrahymena
spp. Does Not Require Bacterial Replication and Depends on a Dot/Icm-Mediated Survival Mechanism
Authors: Berk Sharon G. , Faulkner Gary , Garduño Elizabeth , Joy Mark C. , Ortiz-Jimenez Marco A. , Garduño Rafael A. 
Published: February 2008

ABSTRACT

The freshwater ciliate
Tetrahymena
sp. efficiently ingested, but poorly digested, virulent strains of the gram-negative intracellular pathogen
Legionella pneumophila
. Ciliates expelled live legionellae packaged in free spherical pellets. The ingested legionellae showed no ultrastructural indicators of cell division either within intracellular food vacuoles or in the expelled pellets, while the number of CFU consistently decreased as a function of time postinoculation, suggesting a lack of
L. pneumophila
replication inside
Tetrahymena
. Pulse-chase feeding experiments with fluorescent
L. pneumophila
and
Escherichia coli
indicated that actively feeding ciliates maintain a rapid and steady turnover of food vacuoles, so that the intravacuolar residence of the ingested bacteria was as short as 1 to 2 h.
L. pneumophila
mutants with a defective Dot/Icm virulence system were efficiently digested by
Tetrahymena
sp. In contrast to pellets of virulent
L. pneumophila
, the pellets produced by ciliates feeding on
dot
mutants contained very few bacterial cells but abundant membrane whorls. The whorls became labeled with a specific antibody against
L. pneumophila
OmpS, indicating that they were outer membrane remnants of digested legionellae. Ciliates that fed on genetically complemented
dot
mutants produced numerous pellets containing live legionellae, establishing the importance of the Dot/Icm system to resist digestion. We thus concluded that production of pellets containing live virulent
L. pneumophila
depends on bacterial survival (mediated by the Dot/Icm system) and occurs in the absence of bacterial replication. Pellets of virulent
L. pneumophila
may contribute to the transmission of Legionnaires’ disease, an issue currently under investigation.
Abundances and Distributions of the Dominant
nifH
Phylotypes in the Northern Atlantic Ocean
Authors: Langlois Rebecca J. , Hümmer Diana , LaRoche Julie 
Published: February 2008

ABSTRACT

Understanding the factors that influence the distribution and abundance of marine diazotrophs is important in order to assess their role in the oceanic nitrogen cycle. Environmental DNA samples from four cruises to the North Atlantic Ocean, covering a sampling area of 0°N to 42°N and 67°W to 13°W, were analyzed for the presence and amount of seven
nifH
phylotypes using real-time quantitative PCR and TaqMan probes. The cyanobacterial phylotypes dominated in abundance (94% of all
nifH
copies detected) and were the most widely distributed. The filamentous cyanobacterial type, which included both
Trichodesmium
and
Katagnymene
, was the most abundant (51%), followed by group A, an uncultured unicellular cyanobacterium (33%), and gamma A, an uncultured gammaproteobacterium (6%). Group B, unicellular cyanobacterium
Crocosphaera
, and group C
Cyanothece
-like phylotypes were not often detected (6.9% and 2.3%, respectively), but where present, could reach high concentrations. Gamma P, another uncultured gammaproteobacterium, was seldom detected (0.5%). Water temperature appeared to influence the distribution of many
nifH
phylotypes. Very high (up to 1 × 10
6
copies liter
−1
)
nifH
concentrations of group A were detected in the eastern basin (25 to 17°N, 27 to 30°W), where the temperature ranged from 20 to 23°C. The highest concentrations of filamentous phylotypes were measured between 25 and 30°C. The uncultured cluster III phylotype was uncommon (0.4%) and was associated with mean water temperatures of 18°C. Diazotroph abundance was highest in regions where modeled average dust deposition was between 1 and 2 g/m
2
/year.
Construction of Sterileime1Δ-TransgenicSaccharomyces cerevisiaeWine Yeasts Unable To Disseminate in Nature
Authors: Ramírez Manuel , Ambrona Jesús 
Published: February 2008

ABSTRACTThe use of new transgenic yeasts in industry carries a potential environmental risk because their dispersal, introducing new artificial genetic combinations into nature, could have unpredictable consequences. This risk could be avoided by using sterile transgenic yeasts that are unable to sporulate and mate with wild yeasts. These sterile yeasts would not survive the annual cyclic harvesting periods, being condemned to disappear in the wineries and vineyards in less than a year. We have constructed newime1Δwine yeasts that are unable to sporulate and mate, bear easy-to-detect genetic markers, and quickly disappear in grape must fermentation immediately after sporulation of the yeast population. These sterile yeasts maintained the same biotechnological properties as their parent yeasts without any detectable deleterious effect of theime1Δmutation. These yeasts are therefore interesting biotechnologically for food industry applications and for genetically modified microorganism environmental monitoring studies.
Activation of the Diacetyl/Acetoin Pathway in
Lactococcus lactis
subsp.
lactis
bv. diacetylactis CRL264 by Acidic Growth
Authors: García-Quintáns Nieves , Repizo Guillermo , Martín Mauricio , Magni Christian , López Paloma 
Published: February 2008

ABSTRACT

Lactococcus lactis
subsp.
lactis
bv. diacetylactis strains are aroma-producing organisms used in starter cultures for the elaboration of dairy products. This species is essentially a fermentative microorganism, which cometabolizes glucose and citrate to yield aroma compounds through the diacetyl/acetoin biosynthetic pathway. Our previous results have shown that under acidic growth
Lactococcus
bv. diacetylactis CRL264 expresses coordinately the genes responsible for citrate transport and its conversion into pyruvate. In the present work the impact of acidic growth on glucose, citrate, and pyruvate metabolism of
Lactococcus
bv. diacetylactis CRL264 has been investigated by proteomic analysis. The results indicated that acid growth triggers the conversion of citrate, but not glucose, into α-acetolactate via pyruvate. Moreover, they showed that low pH has no influence on levels of lactate dehydrogenase and pyruvate dehydrogenase. Therefore, the influence of external pH on regulation of the diacetyl/acetoin biosynthetic pathway in
Lactococcus
bv. diacetylactis CRL264 has been analyzed at the transcriptional level. Expression of the
als
,
aldB
,
aldC
, and
butBA
genes encoding the enzymes involved in conversion of pyruvate into aroma compounds has been investigated by primer extension, reverse transcription-PCR analysis, and transcriptional fusions. The results support that this biosynthetic pathway is induced at the transcriptional level by acidic growth conditions, presumably contributing to lactococcal pH homeostasis by synthesis of neutral compounds and by decreasing levels of pyruvate.
Antibacterial Activity and Mechanism of Action of the Silver Ion in
Staphylococcus aureus
and
Escherichia coli
Authors: Jung Woo Kyung , Koo Hye Cheong , Kim Ki Woo , Shin Sook , Kim So Hyun , Park Yong Ho 
Published: February 2008

ABSTRACT

The antibacterial effect and mechanism of action of a silver ion solution that was electrically generated were investigated for
Staphylococcus aureus
and
Escherichia coli
by analyzing the growth, morphology, and ultrastructure of the bacterial cells following treatment with the silver ion solution. Bacteria were exposed to the silver ion solution for various lengths of time, and the antibacterial effect of the solution was tested using the conventional plate count method and flow cytometric (FC) analysis. Reductions of more than 5 log
10
CFU/ml of both
S. aureus
and
E. coli
bacteria were confirmed after 90 min of treatment with the silver ion solution. Significant reduction of
S. aureus
and
E. coli
cells was also observed by FC analysis; however, the reduction rate determined by FC analysis was less than that determined by the conventional plate count method. These differences may be attributed to the presence of bacteria in an active but nonculturable (ABNC) state after treatment with the silver ion solution. Transmission electron microscopy showed considerable changes in the bacterial cell membranes upon silver ion treatment, which might be the cause or consequence of cell death. In conclusion, the results of the present study suggest that silver ions may cause
S. aureus
and
E. coli
bacteria to reach an ABNC state and eventually die.
Autoinducer-2 Triggers the Oxidative Stress Response in
Mycobacterium avium
, Leading to Biofilm Formation
Authors: Geier Henriette , Mostowy Serge , Cangelosi Gerard A. , Behr Marcel A. , Ford Timothy E. 
Published: February 2008

ABSTRACT

Mycobacterium avium
is an environmental organism and opportunistic pathogen with inherent resistance to drugs, environmental stresses, and the host immune response. To adapt to these disparate conditions,
M. avium
must control its transcriptional response to environmental cues.
M. avium
forms biofilms in various environmental settings, including drinking water pipes and potable water reservoirs. In this study, we investigated the role of the universal signaling molecule autoinducer-2 (AI-2) in biofilm formation by
M. avium
. The addition of the compound to planktonic
M. avium
cultures resulted in increased biofilm formation. Microarray and reverse transcriptase PCR studies revealed an upregulation of the oxidative stress response upon addition of AI-2. This suggests that the response to AI-2 might be related to oxidative stress, rather than quorum sensing. Consistent with this model, addition of hydrogen peroxide, a known stimulus of the oxidative stress response, to
M. avium
cultures resulted in elevated biofilm formation. These results suggest that AI-2 does not act as a quorum-sensing signal in
M. avium
. Instead, biofilm formation is triggered by environmental stresses of biotic and abiotic origins and AI-2 may exert effects on that level.
Survival of Gastric and Enterohepatic
Helicobacter
spp. in Water: Implications for Transmission
Authors: Azevedo N. F. , Almeida C. , Fernandes I. , Cerqueira L. , Dias S. , Keevil C. W. , Vieira M. J. 
Published: February 2008

ABSTRACT

Part of the reason for rejecting aquatic environments as possible vectors for the transmission of
Helicobacter pylori
has been the preference of this microorganism to inhabit the human stomach and hence use a direct oral-oral route for transmission. On the other hand, most enteric bacterial pathogens are well known for being able to use water as an environmental reservoir. In this work, we have exposed 13 strains of seven different
Helicobacter
spp. (both gastric and enterohepatic) to water and tracked their survival by standard plating methods and membrane integrity assessment. The influence of different plating media and temperatures and the presence of light on recovery was also assessed. There was good correlation between cultivability and membrane integrity results (Pearson's correlation coefficient = 0.916), confirming that the culture method could reliably estimate differences in survival among different
Helicobacter
spp. The species that survived the longest in water was
H. pylori
(>96 h in the dark at 25°C), whereas
H. felis
appeared to be the most sensitive to water (<6 h). A hierarchical cluster analysis demonstrated that there was no relationship between the enterohepatic nature of
Helicobacter
spp. and an increased time of survival in water. This work assesses for the first time the survival of multiple
Helicobacter
spp., such has
H. mustelae
,
H. muridarum
,
H. felis
,
H. canadensis
,
H. pullorum
, and
H. canis
, in water under several conditions and concludes that the roles of water in transmission between hosts are likely to be similar for all these species, whether enterohepatic or not.
Genomic and Genetic Characterization of the Bile Stress Response of ProbioticLactobacillus reuteriATCC 55730
Authors: Whitehead Kristi , Versalovic James , Roos Stefan , Britton Robert A. 
Published: February 2008

ABSTRACTProbiotic bacteria encounter various stresses after ingestion by the host, including exposure to the low pH in the stomach and bile in the small intestine. The probiotic microorganismLactobacillus reuteriATCC 55730 has previously been shown to survive in the human small intestine. To address howL. reuterican resist bile stress, we performed microarray experiments to determine gene expression changes that occur when the organism is exposed to physiological concentrations of bile. A wide variety of genes that displayed differential expression in the presence of bile indicated that the cells were dealing with several types of stress, including cell envelope stress, protein denaturation, and DNA damage. Mutations in three genes were found to decrease the strain's ability to survive bile exposure: lr1864, a Clp chaperone; lr0085, a gene of unknown function; and lr1516, a putative esterase. Mutations in two genes that form an operon, lr1584 (a multidrug resistance transporter in the major facilitator superfamily) and lr1582 (unknown function), were found to impair the strain's ability to restart growth in the presence of bile. This study provides insight into the possible mechanisms thatL. reuteriATCC 55730 may use to survive and grow in the presence of bile in the small intestine.