bluuebunny/crossref_metadata_2025_split huggingface dataset:
Withered Milpas: Governmental Disaster and the Mexican Countryside
Authors: Richard Analiese 
Published: November 2008

RESUMENLos teoristas de la globalización han demonstrado como los proyectos destinados a profundizar la integración trasnacional económica y política, pueden producir nuevas formas de riesgo y vulnerabilidad. Los desastres ‐ naturales o no ‐ sirven como encrucijadas, por medio de las que se revelan varios enlaces: entre las estructuras de poder locales y globales, entre la cultura ideológica y material, entre las sociedades humanas y los ambientes naturales. Este artículo investiga como los efectos sinergisticos de la integración económica norteamericana, la privatización y corporatización de la agricultura mexicana, los mercados internacionales del maíz inestables, y el cambio climático global, se experimentan como un “desastre gubernamental” en las vidas de los campesinos del estado de Hidalgo, México. El presente estudio analiza como una consciencia particular acerca de la catástrofe es producida y comunicada por medio de un disurso de la desecación, el cual se basa en ideas tradicionales sobre la explotación y la vulnerabilidad. Vivir el desastre como una exclusión permanente de las formas politicas colectivas, sirve para reforzar y respaldar a los proyectos de neoliberalización que funcionan para individualizar las practíces de ciudadanía en el campo mexicano.Globalization theorists have demonstrated how projects aimed at deepening transnational economic and political integration produce new forms of risk and vulnerability. Disasters—natural and otherwise—serve as critical nodes through which a variety of links are revealed: between local and global power structures, ideological and material culture, and human societies, and natural environments. This article examines how the synergistic effects of North American economic integration, the privatization and corporatization of Mexican agriculture, volatile international maize markets, and global climate change are experienced as a “governmental disaster” by campesinos [small farmers] in the state of Hidalgo, Mexico. It analyzes how a particular consciousness of catastrophe is produced and articulated via a discourse of desiccation, which indexes traditional notions concerning exploitation and vulnerability. The experience of disaster as a foreclosure of collective forms of political agency serves to reinforce neoliberalizing projects that work to individuate practices of citizenship in the Mexican countryside.
Long-Term Monensin Supplementation Does Not Significantly Affect the Quantity or Diversity of Methanogens in the Rumen of the Lactating Dairy Cow
Authors: Hook S. E. , Northwood K. S. , Wright A.-D. G. , McBride B. W. 
Published: November 2008

ABSTRACT

A long-term monensin supplementation trial involving lactating dairy cattle was conducted to determine the effect of monensin on the quantity and diversity of rumen methanogens in vivo. Fourteen cows were paired on the basis of days in milk and parity and allocated to one of two treatment groups, receiving (i) a control total mixed ration (TMR) or (ii) a TMR with 24 mg of monensin premix/kg of diet dry matter. Rumen fluid was obtained using an ororuminal probe on day −15 (baseline) and days 20, 90, and 180 following treatment. Throughout the 6-month experiment, the quantity of rumen methanogens was not significantly affected by monensin supplementation, as measured by quantitative real-time PCR. The diversity of the rumen methanogen population was investigated using denaturing gradient gel electrophoresis (DGGE) and 16S rRNA clone gene libraries. DGGE analysis at each sampling point indicated that the molecular diversity of rumen methanogens from monensin-treated cattle was not significantly different from that of rumen methanogens from control cattle. 16S rRNA gene libraries were constructed from samples obtained from the rumen fluids of five cows, with a total of 166 clones examined. Eleven unique 16S rRNA sequences or phylotypes were identified, five of which have not been recognized previously. The majority of clones (98.2%) belonged to the genus
Methanobrevibacter
, with all libraries containing
Methanobrevibacter
strains M6 and SM9 and a novel phylotype, UG3322.2. Overall, long-term monensin supplementation was not found to significantly alter the quantity or diversity of methanogens in the rumens of lactating dairy cattle in the present study.
Antimicrobial Susceptibility Profiles and Strain Type Diversity of
Campylobacter jejuni
Isolates from Turkeys in Eastern North Carolina
Authors: Gu Weimin , Siletzky Robin M. , Wright Sandra , Islam Mohammed , Kathariou Sophia 
Published: November 2008

ABSTRACT

Campylobacter jejuni
is one of the most common bacterial causes of human gastroenteritis, and recent findings suggest that turkeys are an important reservoir for this organism. In this study, 80
C. jejuni
isolates from eastern North Carolina were characterized for resistance to nine antimicrobials, and strain types were determined by
fla
typing, pulsed-field gel electrophoresis (PFGE) with SmaI and KpnI, and (for 41 isolates) multilocus sequence typing (MLST). PFGE analysis suggested that many of the isolates (37/40 [ca. 93%]) in a major genomic cluster had DNA that was partially methylated at SmaI sites. Furthermore, 12/40 (30%) of the isolates in this cluster were completely resistant to digestion by KpnI, suggesting methylation at KpnI sites. MLST of 41 isolates identified 10 sequence types (STs), of which 4 were new. Three STs (ST-1839, ST-2132 and the new ST-2934) were predominant and were detected among isolates from different farms. The majority of the isolates (74%) were resistant to three or more antimicrobials, and resistance to ciprofloxacin was common (64%), whereas resistance to the other drug of choice for treatment of human campylobacteriosis, erythromycin, was never encountered. Most (33/34) of the kanamycin-resistant isolates were also resistant to tetracycline; however, only ca. 50% of the tetracycline-resistant isolates were also kanamycin resistant. Isolates with certain antimicrobial resistance profiles had identical or closely related strain types. Overall, the findings suggest dissemination of certain clonal groups of
C. jejuni
isolates in the turkey production industry of this region.
Endocytosis Is Crucial for Cell Polarity and Apical Membrane Recycling in the Filamentous Fungus
Aspergillus oryzae
Authors: Higuchi Yujiro , Shoji Jun-ya , Arioka Manabu , Kitamoto Katsuhiko 
Published: November 2008

ABSTRACT

Establishing the occurrence of endocytosis in filamentous fungi was elusive in the past mainly due to the lack of reliable indicators of endocytosis. Recently, however, it was shown that the fluorescent dye
N
-(3-triethylammoniumpropyl)-4-(
p
-diethyl-aminophenyl-hexatrienyl)pyridinium dibromide (FM4-64) and the plasma membrane protein AoUapC (
Aspergillus oryzae
UapC) fused to enhanced green fluorescent protein (EGFP) were internalized from the plasma membrane by endocytosis. Although the occurrence of endocytosis was clearly demonstrated, its physiological importance in filamentous fungi still remains largely unaddressed. We generated a strain in which
A. oryzae end4
(Ao
end4
), the
A. oryzae
homolog of
Saccharomyces cerevisiae END4
/
SLA2
, was expressed from the Ao
end4
locus under the control of a regulatable
thiA
promoter. The growth of this strain was severely impaired, and its hyphal morphology was altered in the Ao
end4
-repressed condition. Moreover, in the Ao
end4
-repressed condition, neither FM4-64 nor AoUapC-EGFP was internalized, indicating defective endocytosis. Furthermore, the localization of a secretory soluble
N
-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) was abnormal in the Ao
end4
-repressed condition. Aberrant accumulation of cell wall components was also observed by calcofluor white staining and transmission electron microscopy analysis, and several genes that encode cell wall-building enzymes were upregulated, indicating that the regulation of cell wall synthesis is abnormal in the Ao
end4
-repressed condition, whereas Ao
pil1
disruptants do not display the phenotype exhibited in the Ao
end4
-repressed condition. Our results strongly suggest that endocytosis is crucial for the hyphal tip growth in filamentous fungi.
Sphingolipid C-9 Methyltransferases Are Important for Growth and Virulence but Not for Sensitivity to Antifungal Plant Defensins inFusarium graminearum
Authors: Ramamoorthy Vellaisamy , Cahoon Edgar B. , Thokala Mercy , Kaur Jagdeep , Li Jia , Shah Dilip M. 
Published: November 2008

ABSTRACTThe C-9-methylated glucosylceramides (GlcCers) are sphingolipids unique to fungi. They play important roles in fungal growth and pathogenesis, and they act as receptors for some antifungal plant defensins. We have identified two genes, FgMT1and FgMT2, that each encode a putative sphingolipid C-9 methyltransferase (C-9-MT) in the fungal pathogenFusarium graminearumand complement aPichia pastorisC-9-MT-null mutant. The ΔFgmt1mutant produced C-9-methylated GlcCer like the wild-type strain, PH-1, whereas the ΔFgmt2mutant produced 65 to 75% nonmethylated and 25 to 35% methylated GlcCer. No ΔFgmt1ΔFgmt2double-knockout mutant producing only nonmethylated GlcCer could be recovered, suggesting that perhaps C-9-MTs are essential in this pathogen. This is in contrast to the nonessential nature of this enzyme in the unicellular fungusP. pastoris. The ΔFgmt2mutant exhibited severe growth defects and produced abnormal conidia, while the ΔFgmt1mutant grew like the wild-type strain, PH-1, under the conditions tested. The ΔFgmt2mutant also exhibited drastically reduced disease symptoms in wheat and much-delayed disease symptoms inArabidopsis thaliana. Surprisingly, the ΔFgmt2mutant was less virulent on different host plants tested than the previously characterized ΔFggcs1mutant, which lacks GlcCer synthase activity and produces no GlcCer at all. Moreover, the ΔFgmt1and ΔFgmt2mutants, as well as theP. pastorisstrain in which the C-9-MT gene was deleted, retained sensitivity to the antifungal plant defensins MsDef1 and RsAFP2, indicating that the C-9 methyl group is not a critical structural feature of the GlcCer receptor required for the antifungal action of plant defensins.
Transcriptional Profiling Identifies a Role for BrlA in the Response to Nitrogen Depletion and for StuA in the Regulation of Secondary Metabolite Clusters in
Aspergillus fumigatus
Authors: Twumasi-Boateng Kwame , Yu Yan , Chen Dan , Gravelat Fabrice N. , Nierman William C. , Sheppard Donald C. 
Published: November 2008

ABSTRACT

Conidiation (asexual sporulation) is a key developmental process in filamentous fungi. We examined the gene regulatory roles of the
Aspergillus fumigatus
developmental transcription factors StuAp and BrlAp during conidiation. Conidiation was completely abrogated in an
A. fumigatus
Δ
brlA
mutant and was severely impaired in a Δ
stuA
mutant. We determined the full genome conidiation transcriptomes of wild-type and Δ
brlA
and Δ
stuA
mutant
A. fumigatus
and found that BrlAp and StuAp governed overlapping but distinct transcriptional programs. Six secondary metabolite biosynthetic clusters were found to be regulated by StuAp, while only one cluster exhibited BrlAp-dependent expression. The Δ
brlA
mutant, but not the Δ
stuA
mutant, had impaired downregulation of genes encoding ribosomal proteins under nitrogen-limiting, but not carbon-limiting, conditions. Interestingly, inhibition of the target of rapamycin (TOR) pathway also caused downregulation of ribosomal protein genes in both the wild-type strain and the Δ
brlA
mutant. Downregulation of these genes by TOR inhibition was associated with conidiation in the wild-type strain but not in the Δ
brlA
mutant. Therefore, BrlAp-mediated repression of ribosomal protein gene expression is not downstream of the TOR pathway. Furthermore, inhibition of ribosomal protein gene expression is not sufficient to induce conidiation in the absence of BrlAp.
Evidence of a Reduced and Modified Mitochondrial Protein Import Apparatus in Microsporidian Mitosomes
Authors: Waller Ross F. , Jabbour Carole , Chan Nickie C. , Celik Nermin , Likić Vladimir A. , Mulhern Terrence D. , Lithgow Trevor 
Published: November 2008

ABSTRACT

Microsporidia are a group of highly adapted obligate intracellular parasites that are now recognized as close relatives of fungi. Their adaptation to parasitism has resulted in broad and severe reduction at (i) a genomic level by extensive gene loss, gene compaction, and gene shortening; (ii) a biochemical level with the loss of much basic metabolism; and (iii) a cellular level, resulting in lost or cryptic organelles. Consistent with this trend, the mitochondrion is severely reduced, lacking ATP synthesis and other typical functions and apparently containing only a fraction of the proteins of canonical mitochondria. We have investigated the mitochondrial protein import apparatus of this reduced organelle in the microsporidian
Encephalitozoon cuniculi
and find evidence of reduced and modified machinery. Notably, a putative outer membrane receptor, Tom70, is reduced in length but maintains a conserved structure chiefly consisting of tetratricopeptide repeats. When expressed in
Saccharomyces cerevisiae
, EcTom70 inserts with the correct topology into the outer membrane of mitochondria but is unable to complement the growth defects of Tom70-deficient yeast. We have scanned genomic data using hidden Markov models for other homologues of import machinery proteins and find evidence of severe reduction of this system.
Glucose- and Glucokinase-ControlledmalGene Expression inEscherichia coli
Authors: Lengsfeld Christina , Schönert Stefan , Dippel Renate , Boos Winfried 
Published: November 2008

ABSTRACTMalT is the central transcriptional activator of allmalgenes inEscherichia coli. Its activity is controlled by the inducer maltotriose. It can be inhibited by the interaction with certain proteins, and its expression can be controlled. We report here a novel aspect ofmalgene regulation: the effect of cytoplasmic glucose and glucokinase (Glk) on the activity and the expression of MalT. Amylomaltase (MalQ) is essential for the metabolism of maltose. It forms maltodextrins and glucose from maltose or maltodextrins. We found that glucose above a concentration of 0.1 mM blocked the activity of the enzyme.malQmutants when grown in the absence of maltodextrins are endogenously induced by maltotriose that is derived from the degradation of glycogen. Therefore, the fact thatglk malQ+mutants showed elevatedmalgene expression finds its explanation in the reduced ability to remove glucose from MalQ-catalyzed maltodextrin formation and is caused by a metabolically induced MalQ−phenotype. However, even in mutants lacking glycogen, Glk controls endogenous induction. We found that overexpressed Glk due to its structural similarity with Mlc, the repressor ofmalT, binds to the glucose transporter (PtsG), releasing Mlc and thus increasingmalTrepression. In addition, even in mutants lacking Mlc (and glycogen), the overexpression ofglkleads to a reduction inmalgene expression. We interpret this repression by a direct interaction of Glk with MalT concomitant with MalT inhibition. This repression was dependent on the presence of either maltodextrin phosphorylase or amylomaltase and led to the inactivation of MalT.
Response ofPorphyromonas gingivalisto Heme Limitation in Continuous Culture
Authors: Dashper Stuart G. , Ang Ching-Seng , Veith Paul D. , Mitchell Helen L. , Lo Alvin W. H. , Seers Christine A. , Walsh Katrina A. , Slakeski Nada , Chen Dina , Lissel J. Patricia , Butler Catherine A. , O'Brien-Simpson Neil M. , Barr Ian G. , Reynolds Eric C. 
Published: November 2008

ABSTRACTPorphyromonas gingivalisis an anaerobic, asaccharolytic, gram-negative bacterium that has essential requirements for both iron and protoporphyrin IX, which it preferentially obtains as heme. A combination of large-scale quantitative proteomic analysis using stable isotope labeling strategies and mass spectrometry, together with transcriptomic analysis using custom-made DNA microarrays, was used to identify changes inP. gingivalisW50 protein and transcript abundances on changing from heme-excess to heme-limited continuous culture. This approach identified 160 genes and 70 proteins that were differentially regulated by heme availability, with broad agreement between the transcriptomic and proteomic data. A change in abundance of the enzymes of the aspartate and glutamate catabolic pathways was observed with heme limitation, which was reflected in organic acid end product levels of the culture fluid. These results demonstrate a shift from an energy-efficient anaerobic respiration to a less efficient process upon heme limitation. Heme limitation also resulted in an increase in abundance of a protein, PG1374, which we have demonstrated, by insertional inactivation, to have a role in epithelial cell invasion. The greater abundance of a number of transcripts/proteins linked to invasion of host cells, the oxidative stress response, iron/heme transport, and virulence of the bacterium indicates that there is a broad response ofP. gingivalisto heme availability.
Insertion and Deletion Events That Define the PathogenMycobacterium aviumsubsp.paratuberculosis
Authors: Alexander David C. , Turenne Christine Y. , Behr Marcel A. 
Published: November 2008

ABSTRACTMycobacterium aviumcomprises genetically related yet phenotypically distinct subspecies. Consistent with their common origin, whole-genome sequence comparisons have revealed extensive synteny amongM. aviumorganisms. However, the sequenced strains also display numerous regions of heterogeneity that likely contribute to the diversity of the individual subspecies. Starting from a phylogenetic framework derived by multilocus sequence analysis, we examined the distribution of 25 large sequence polymorphisms across a panel of genetically definedM. aviumstrains. This distribution was most variable amongM. aviumsubsp.hominissuisisolates. In contrast,M. aviumsubsp.paratuberculosisstrains exhibited a characteristic profile, with all isolates containing a set of genomic insertions absent from otherM. aviumstrains. The emergence of the pathogen from its putativeM. aviumsubsp.hominissuisancestor entailed the acquisition of approximately 125 kb of novel genetic material, followed by a second phase, characterized by reductive genomics. One genomic deletion is common to all isolates while additional deletions distinguish two major lineages ofM. aviumsubsp.paratuberculosis. For the average strain, these losses total at least 38 kb (sheep lineage) to 90 kb (cattle lineage). This biphasic pattern of evolution, characterized by chromosomal gene acquisition with subsequent gene loss, describes the emergence ofM. aviumsubsp.paratuberculosisand may serve as a general model for the origin of pathogenic mycobacteria.
Identification and Characterization of NocR as a Positive Transcriptional Regulator of the β-Lactam Nocardicin A inNocardia uniformis
Authors: Davidsen Jeanne M. , Townsend Craig A. 
Published: November 2008

ABSTRACTNocardicin A is a monocyclic β-lactam isolated from the actinomyceteNocardia uniformis, which shows moderate activity against a broad spectrum of gram-negative bacteria. Within the biosynthetic gene cluster of nocardicin A,nocRencodes a 583-amino-acid protein with high similarity to a class of transcriptional regulators known asstreptomycesantibioticregulatoryproteins. Insertional inactivation of this gene resulted in a mutant showing morphology and growth characteristics similar to the wild type, but one that did not produce detectable levels of nocardicin A or the early precursorp-hydroxybenzoyl formate. Similar disruptions ofnocD,nocE, andnocOyielded mutants that maintained production of nocardicin A at levels similar to the wild-type strain. Intranscomplementation of thenocR::aprmutant partially restored the wild-type phenotype. Transcriptional analysis of thenocR::aprmutant using reverse transcription-PCR found an absence of mRNA transcripts for the early-stage nocardicin A biosynthetic genes. In addition, transcription of the genes responsible for the biosynthesis of the nonproteinogenicp-hydroxyphenylglycine (pHPG) precursor was attenuated on thenocRdisruption mutant. NocR was heterologously expressed and purified fromEscherichia colias an N-terminal maltose binding protein-tagged fusion protein. DNA binding assays demonstrated that NocR is a DNA binding protein, targeting the 126-bp intergenic region betweennocFandnocA. Within this intergenic region is the likely binding motif, a direct hexameric repeat, TGATAA, with a 5-bp spacer. These experiments establish NocR as a positive transcriptional regulator of the nocardicin A biosynthetic pathway, coordinating the initial steps of nocardicin A biosynthesis to the production of its pHPG precursor.
Imaging of the retinal nerve fibre layer for glaucoma
Authors: Townsend K A , Wollstein G , Schuman J S 
Published: November 2008

Background:Glaucoma is a group of diseases characterised by retinal ganglion cell dysfunction and death. Detection of glaucoma and its progression are based on identification of abnormalities or changes in the optic nerve head (ONH) or the retinal nerve fibre layer (RNFL), either functional or structural. This review will focus on the identification of structural abnormalities in the RNFL associated with glaucoma.Discussion:A variety of new techniques have been created and developed to move beyond photography, which generally requires subjective interpretation, to quantitative retinal imaging to measure RNFL loss. Scanning laser polarimetry uses polarised light to measure the RNFL birefringence to estimate tissue thickness. Optical coherence tomography (OCT) uses low-coherence light to create high-resolution tomographic images of the retina from backscattered light in order to measure the tissue thickness of the retinal layers and intraretinal structures. Segmentation algorithms are used to measure the thickness of the retinal nerve fibre layer directly from the OCT images. In addition to these clinically available technologies, new techniques are in the research stages. Polarisation-sensitive OCT has been developed that combines the strengths of scanning laser polarimetry with those of OCT. Ultra-fast techniques for OCT have been created for research devices. The continued utilisation of imaging devices into the clinic is refining glaucoma assessment. In the past 20 years glaucoma has gone from a disease diagnosed and followed using highly subjective techniques to one measured quantitatively and increasingly objectively.
Incidence of acute pesticide poisonings in Nicaragua: a public health concern
Authors: Corriols M , Marín J , Berroteran J , Lozano L M , Lundberg I 
Published: November 2008

Objectives:To estimate the cumulative incidence rate of acute pesticide poisoning in the year 2000 among Nicaraguan subjects over 15 years of age.Methods:Data on pesticide exposure and health effects were assessed in a nationally representative survey. Based on self-reported cases, we estimated the 1-year incidence rate and the number of expected cases of acute pesticide poisonings in Nicaragua.Results:Among the 3169 survey respondents, we identified 72 persons who self-reported one episode of acute pesticide poisoning in 2000. Of these, 65 cases (90%) were related to occupational exposure, five (7%) to domestic exposure and two (3%) to intentional exposure. The cumulative incidence rate/100 individuals of pesticide poisonings in Nicaragua in 2000 was 2.3 (95% CI 1.7 to 2.8). This corresponds to 66 113 cases (95% CI 51 017 to 81 210). The highest rate was found among males in rural areas, particularly among farmers and agricultural workers.Conclusion:This study demonstrates an extremely high risk of acute pesticide poisoning in Nicaragua. Considering this, comprehensive measures should be implemented to reduce adverse health effects.