bluuebunny/crossref_metadata_2025 huggingface dataset:
IMPERVIOUSNESS: A PERFORMANCE MEASURE OF A DELAWARE WATER RESOURCE PROTECTION AREA ORDINANCE1
Authors: Kauffman Gerald J. , Corrozi Martha B. , Vonck Kevin J.
Published: June 2007

ABSTRACT: The New Castle County Resource Protection Area Technical Advisory Committee (RPATAC) requested that the University of Delaware utilize impervious cover estimates to evaluate the performance of the Water Resource Protection Area (WRPA) ordinance. This 1991 ordinance was the first in Delaware to protect the quantity and quality of drinking water supplies by limiting new development in WRPAs ‐ such as areas of ground water recharge, wellhead protection, drainage above reservoirs (reservoir watersheds), and limestone aquifers ‐ to a maximum 20 percent impervious cover. The research used geographic information system (GIS) techniques to evaluate the effectiveness of the ordinance in attaining its objective. The analysis indicated that 138 new developments were proposed in WRPAs since the ordinance was approved in 1991. The composite impervious cover of the 231 square kilometers of WRPAs in New Castle County is 15 percent, less than the 20 percent code requirement, ranging from 7 percent in recharge areas to 41 percent in several wellhead protection areas. To further protect drinking water supplies, the study results indicate, New Castle County should discourage code variances for applications in the more developed WRPAs, those where impervious cover already exceeds 20 percent, and should acquire parks and open space to protect the healthier WRPAs where impervious cover is currently less than 20 percent.
SIMULATED EFFECTS OF ALTERED SPILLWAY RELEASES ON THERMAL STRUCTURE AND KOKANEE GROWTH IN A COLORADO RESERVOIR1
Authors: Saito Laurel , Koski Marci
Published: June 2007

ABSTRACT:In‐reservoir thermal and ecological effects of releasing some flows over the surface spillway at Blue Mesa Reservoir, Colorado, rather than routing all releases through the hypolimnetic outlet were evaluated using a calibrated and validated one‐dimensional thermal model (CE‐THERM) with a set of ecological models. Thermal model output indicated that surface water temperatures were influenced primarily by atmospheric conditions, but the release of warmer water over the spillway resulted in a thinner epilimnion and cooler metalimnetic water temperatures. Ecological model predictions indicated that spillway releases and associated temperatures resulted in lower growth rates for young‐of‐year (YOY) kokanee salmon (Oncorhynchus nerka) in the reservoir by up to 9 percent when compared with growth rates under baseline operations with no releases over the spillway. Kokanee growth rates were reduced under spillway release scenarios because lower temperatures not only affected metabolic rates, but limited the productivity of the zooplankton as well. Thus, altering the release regime with spillway discharges could have deleterious effects on Blue Mesa's YOY kokanee. However, in other reservoirs, distributing discharges among different elevations may provide managers with a mechanism to regulate temperatures to benefit species of concern that are facing challenges imposed by environmental conditions such as global warming.
EVALUATION OF EROSION CONTROL PRODUCTS WITH AND WITHOUT ADDED POLYACRYLAMIDE1
Authors: McLaughlin Richard A. , Brown Tabitha T.
Published: June 2007

ABSTRACT: Polyacrylamide (PAM) has been demonstrated to greatly reduce erosion in furrow irrigation, but much less is known about its effectiveness on the much steeper slopes typical of construction sites. The purpose of this study was to determine if anionic PAM would enhance erosion control either alone on bare soil or in combination with four types of ground covers commonly used for grass establishment: straw, straw erosion control blanket (ECB), wood fiber, and mechanically bonded fiber matrix (MBFM). Tests were conducted under natural rainfall and vegetation on a 4 percent slope (bare soil, straw, ECB, and MBFM) or using a rainfall simulator (bare soil, straw, wood fiber, MBFM) on either 10 percent or 20 percent slope on three different soil substrates. All ground cover treatments were evaluated with and without PAM applied in solution at 19 kg/ha. The straw, ECB, and MBFM significantly reduced runoff volume, average turbidity, and total sediment lost over five rainfall events on the vegetated plots. The addition of PAM to ground covers only occasionally had significant effects on runoff parameters but did significantly increase vegetative coverage overall. The rainfall simulator tests produced similar results after four events, with the straw, wood fiber, and MBFM all having significantly lower turbidity than the bare soil. The PAM significantly reduced turbidity for both the first and second events but did not consistently improve runoff quality after multiple rainfall events for any ground cover‐soil combinations tested. Separate tests of PAM applied before or after straw did not indicate a clear advantage of either approach, but runoff turbidity was often significantly reduced with PAM, especially at the 20 percent slope. Turbidity reductions were attributed to flocculation of eroded sediment.
AN INTEGRATED ONE‐DIMENSIONAL AND TWO‐DIMENSIONAL URBAN STORMWATER FLOOD SIMULATION MODEL1
Authors: Fang Xing , Su Dehui
Published: June 2007

ABSTRACT: Flash flooding is the rapid flooding of low lying areas caused by the stormwater of intense rainfall associated with thunderstorms. Flash flooding occurs in many urban areas with relatively flat terrain and can result in severe property damage as well as the loss of lives. In this paper, an integrated one‐dimensional (1‐D) and two‐dimensional (2‐D) hydraulic simulation model has been established to simulate stormwater flooding processes in urban areas. With rainfall input, the model simulates 2‐D overland flow and 1‐D flow in underground stormwater pipes and drainage channels. Drainage channels are treated as special flow paths and arranged along one or more sides of a 2‐D computational grid. By using irregular computation grids, the model simulates unsteady flooding and drying processes over urban areas with complex drainage systems. The model results can provide spatial flood risk information (e.g., water depth, inundation time and flow velocity during flooding). The model was applied to the City of Beaumont, Texas, and validated with the recorded rainfall and runoff data from Tropical Storm Allison with good agreement.
THE IMPACT OF RUNOFF GENERATION MECHANISMS ON THE LOCATION OF CRITICAL SOURCE AREAS1
Authors: Lyon Steve W. , McHale Michael R. , Walter M. Todd , Steenhuis Tammo S.
Published: June 2007

ABSTRACT: Identifying phosphorus (P) source areas and transport pathways is a key step in decreasing P loading to natural water systems. This study compared the effects of two modeled runoff generation processes ‐ saturation excess and infiltration excess ‐ on total phosphorus (TP) and soluble reactive phosphorus (SRP) concentrations in 10 catchment streams of a Catskill mountain watershed in southeastern New York. The spatial distribution of runoff from forested land and agricultural land was generated for both runoff processes; results of both distributions were consistent with Soil Conservation Service‐Curve Number (SCS‐CN) theory. These spatial runoff distributions were then used to simulate stream concentrations of TP and SRP through a simple equation derived from an observed relation between P concentration and land use; empirical results indicate that TP and SRP concentrations increased with increasing percentage of agricultural land. Simulated TP and SRP stream concentrations predicted for the 10 catchments were strongly affected by the assumed runoff mechanism. The modeled TP and SRP concentrations produced by saturation excess distribution averaged 31 percent higher and 42 percent higher, respectively, than those produced by the infiltration excess distribution. Misrepresenting the primary runoff mechanism could not only produce erroneous concentrations, it could fail to correctly locate critical source areas for implementation of best management practices. Thus, identification of the primary runoff mechanism is critical in selection of appropriate models in the mitigation of nonpoint source pollution. Correct representation of runoff processes is also critical in the future development of biogeochemical transport models, especially those that address nutrient fluxes.
COMPARISON OF HSPF OUTPUTS USING FTABLES GENERATED WITH FIELD SURVEY AND DIGITAL DATA1
Authors: Staley Nathan , Bright Tiffany , Zeckoski Rebecca W. , Benham Brian L. , Brannan Kevin M.
Published: June 2007

ABSTRACT: The Hydrological Simulation Program‐FORTRAN (HSPF) describes discharge from a stream reach based on function tables (FTABLES) that relate stream stage, surface area, volume, and discharge. For this study, five FTABLE scenarios were compared to assess their effect on daily discharge rates predicted using HSPF. Four “field‐based” FTABLE scenarios were developed using detailed cross section surveys collected at predefined intervals along 14 reaches in the study watershed. A fifth “digital‐based” scenario was developed using digital elevation models (DEMs) and Natural Resource Conservation Service (NRCS) Regional Hydraulic Geometry Curves. The Smirnov k‐sample test was used to compare average daily discharge rates simulated with HSPF using the five FTABLE scenarios. No significant difference in simulated stream discharge was found (p = 0.99) between the five FTABLE scenarios. Additional examination of the four field‐based scenarios revealed that the number of cross sections per stream reach used to generate FTABLES had little effect on the resulting stage discharge relationship. These findings suggest that FTABLES generated using digital data are a viable option when simulating stream discharge with HSPF and that if field data are used to generate FTABLES, using fewer cross sections will not adversely affect simulated discharge predictions.
WATER MANAGEMENT AND N, P LOSSES FROM PADDY FIELDS IN SOUTHERN KOREA1
Authors: Yoon Kwang‐Sik , Cho Jae‐Young , Choi Jin‐Kyu , Son Jae‐Gwon
Published: June 2007

ABSTRACT:Assessment and control of nutrient losses from paddy fields is important to protect water quality of lakes and streams in Korea. A four‐year field study was carried out to investigate water management practices and losses of nitrogen (N) and phosphorus (P) in rice paddy irrigation fields in southern Korea. The amount and water quality of rainfall, irrigation, surface drainage, and infiltration were measured and analyzed to estimate inputs and losses of N and P. The observed irrigation amount surpassed consumptive use, and approximately 52 to 69 percent of inflow (precipitation plus irrigation) was lost to surface drainage. Field data showed that significant amounts of irrigation water and rainfall were not effectively used for rice paddy culture. Water quality data indicated that drainage from paddy fields could degrade the recipient water environment. The nutrient balance indicated that significant amounts of nutrients (29.5 percent of total N and 8.6 percent of total P compared to input) were lost through surface drainage. Furthermore, up to half the nutrient losses occurred during nonstorm periods. The study results indicate that inadequate water management influences N and P losses during both storm and nonstorm periods. Proper water management is required to reduce nutrient losses through surface drainage from paddy fields; this includes such measures as minimum irrigation, effective use of rainfall, adoption of proper drainage outlet structures, and minimized forced surface drainage.
EFFECTS OF STATSGO AND SSURGO AS INPUTS ON SWAT MODEL'S SNOWMELT SIMULATION1
Authors: Wang Xixi , Melesse Assefa M.
Published: June 2007

ABSTRACT: Soil data comprise a basic input of SWAT (Soil and Water Assessment Tool) for a watershed application. For watersheds where site specific soil data are unavailable, the two U.S. Department of Agriculture (USDA) soil databases, the State Soil Geographic (STATSGO) and Soil Survey Geographic (SSURGO) databases, may be the best alternatives. Although it has been noted that SWAT models using the STATSGO and SSURGO data may give different simulation results for water, sediment, and agricultural chemical yields, information is scarce on the effects of using these two databases in predicting streamflows that are predominantly generated from melting snow in spring. The objective of this study was to assess the effects of using STATSGO versus SSURGO as an input for the SWAT model's simulation of the streamflows in the upper 45 percent of the Elm River watershed in eastern North Dakota. Designating the model as SWAT‐STATSGO when the STATSGO data were used and SWAT‐SSURGO when the SSURGO data were used, SWAT‐STATSGO and SWAT‐SSURGO were separately calibrated and validated using the observed daily streamflows. The results indicated that SWAT‐SSURGO provided an overall better prediction of the discharges than SWAT‐STATSGO, although both did a good and comparable job of predicting the high streamflows. However, SWAT‐STATSGO predicted the low streamflows more accurately and had a slightly better performance during the validation period. In addition, the discrepancies between the discharges predicted by these two SWAT models tended to be larger at upstream locations than at those farther downstream within the study area.
Visualization, Intuition, and Mathematics Metrics as Predictors of Undergraduate Engineering Design Performance
Authors: Field Bruce W.
Published: June 2007

Many undergraduate engineering students perform relatively poorly in design courses, even though they are otherwise academically very strong. Some average students perform exceptionally well in design courses. While there are generally strong correlations between the results that each student gains at university, the design outcomes seem somewhat anomalous. It is hypothesized that some of the variation in relative success at design courses is due to the influence of otherwise unused and unmeasured nonacademic attributes. One clue to the existence of additional attributes exploited in design courses arises from an appreciation of “hemispheric preference,” since many of the special tasks in design projects rely on creativity, holistic problem solving, visualization, and intuition; skills normally associated with the brain’s right hemisphere. Students in the second year of the engineering program at Monash University were tested for spatial skill, and completed a management survey that identified their willingness to use intuition during problem solving. Separately, their grades in a series of mathematics and computing courses were obtained, and the set of results was grouped in a multiple regression against their engineering design grades. Whereas the correlation coefficients for the students’ paired grades in several mathematics and other analytical courses were all high, the correlation coefficient between mathematics and their grade in engineering design was weak, but significant. However, when measures of their spatial skills and their willingness to use intuition were factored with their mathematics grade, the composite score was highly correlated with a student’s design grade. It was concluded that while general academic competence was of prime importance, a student’s spatial skill and their comfort in making assumptions were important factors in predicting their design grade.
Identification and Isolation of a
Castellaniella
Species Important during Biostimulation of an Acidic Nitrate- and Uranium-Contaminated Aquifer
Authors: Spain Anne M. , Peacock Aaron D. , Istok Jonathan D. , Elshahed Mostafa S. , Najar Fares Z. , Roe Bruce A. , White David C. , Krumholz Lee R.
Published: June 2007

Immobilization of uranium in groundwater can be achieved through microbial reduction of U(VI) to U(IV) upon electron donor addition. Microbial community structure was analyzed in ethanol-biostimulated and control sediments from a high-nitrate (>130 mM), low-pH, uranium-contaminated site in Oak Ridge, TN. Analysis of small subunit (SSU) rRNA gene clone libraries and polar lipid fatty acids from sediments revealed that biostimulation resulted in a general decrease in bacterial diversity. Specifically, biostimulation resulted in an increase in the proportion of
Betaproteobacteria
(10% of total clones in the control sediment versus 50 and 79% in biostimulated sediments) and a decrease in the proportion of
Gammaproteobacteria
and
Acidobacteria
. Clone libraries derived from dissimilatory nitrite reductase genes (
nirK
and
nirS
) were also dominated by clones related to
Betaproteobacteria
(98% and 85% of total
nirK
and
nirS
clones, respectively). Within the
nirK
libraries, one clone sequence made up 59 and 76% of sequences from biostimulated sediments but only made up 10% of the control
nirK
library. Phylogenetic analysis of SSU rRNA and
nirK
gene sequences from denitrifying pure cultures isolated from the site indicate that all belong to a
Castellaniella
species; nearly identical sequences also constituted the majority of biostimulated SSU rRNA and
nirK
clone libraries. Thus, by combining culture-independent with culture-dependent techniques, we were able to link SSU rRNA clone library information with
nirK
sequence data and conclude that a potentially novel
Castellaniella
species is important for in situ nitrate removal at this site.
Responses of Wild-Type and Resistant Strains of the Hyperthermophilic BacteriumThermotoga maritimato Chloramphenicol Challenge
Authors: Montero Clemente I. , Johnson Matthew R. , Chou Chung-Jung , Conners Shannon B. , Geouge Sarah G. , Tachdjian Sabrina , Nichols Jason D. , Kelly Robert M.
Published: June 2007

Transcriptomes and growth physiologies of the hyperthermophileThermotoga maritimaand an antibiotic-resistant spontaneous mutant were compared prior to and following exposure to chloramphenicol. While the wild-type response was similar to that of mesophilic bacteria, reduced susceptibility of the mutant was attributed to five mutations in 23S rRNA and phenotypic preconditioning to chloramphenicol.
Production of Recombinant β-Hexosaminidase A, a Potential Enzyme for Replacement Therapy for Tay-Sachs and Sandhoff Diseases, in the Methylotrophic Yeast
Ogataea minuta
Authors: Akeboshi Hiromi , Chiba Yasunori , Kasahara Yoshiko , Takashiba Minako , Takaoka Yuki , Ohsawa Mai , Tajima Youichi , Kawashima Ikuo , Tsuji Daisuke , Itoh Kohji , Sakuraba Hitoshi , Jigami Yoshifumi
Published: June 2007

Human β-hexosaminidase A (HexA) is a heterodimeric glycoprotein composed of α- and β-subunits that degrades GM2 gangliosides in lysosomes. GM2 gangliosidosis is a lysosomal storage disease in which an inherited deficiency of HexA causes the accumulation of GM2 gangliosides. In order to prepare a large amount of HexA for a treatment based on enzyme replacement therapy (ERT), recombinant HexA was produced in the methylotrophic yeast
Ogataea minuta
instead of in mammalian cells, which are commonly used to produce recombinant enzymes for ERT. The problem of antigenicity due to differences in N-glycan structures between mammalian and yeast glycoproteins was potentially resolved by using α-1,6-mannosyltransferase-deficient (
och1
Δ) yeast as the host. Genes encoding the α- and β-subunits of HexA were integrated into the yeast cell, and the heterodimer was expressed together with its isozymes HexS (αα) and HexB (ββ). A total of 57 mg of β-hexosaminidase isozymes, of which 13 mg was HexA (αβ), was produced per liter of medium. HexA was purified with immobilized metal affinity column for the His tag attached to the β-subunit. The purified HexA was treated with α-mannosidase to expose mannose-6-phosphate (M6P) residues on the N-glycans. The specific activities of HexA and M6P-exposed HexA (M6PHexA) for the artificial substrate 4MU-GlcNAc were 1.2 ± 0.1 and 1.7 ± 0.3 mmol/h/mg, respectively. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis pattern suggested a C-terminal truncation in the β-subunit of the recombinant protein. M6PHexA was incorporated dose dependently into GM2 gangliosidosis patient-derived fibroblasts via M6P receptors on the cell surface, and degradation of accumulated GM2 ganglioside was observed.
Development of a Novel Genetic System To Create Markerless Deletion Mutants of
Bdellovibrio bacteriovorus
Authors: Steyert Susan R. , Pineiro Silvia A.
Published: June 2007

Bdellovibrio bacteriovorus
is a species of unique obligate predatory bacteria that utilize gram-negative bacteria as prey. Their life cycle alternates between a motile extracellular phase and a growth phase within the prey cell periplasm. The mechanism of prey cell invasion and the genetic networks and regulation during the life cycle have not been elucidated. The obligate predatory nature of the
B. bacteriovorus
life cycle suggests the use of this bacterium in potential applications involving pathogen control but adds complexity to the development of practical genetic systems that can be used to determine gene function. This work reports the development of a genetic technique for allelic exchange or gene inactivation by construction of in-frame markerless deletion mutants including the use of a counterselectable marker in
B. bacteriovorus
. A suicide plasmid carrying the
sacB
gene for counterselection was used to inactivate the
strB
gene in
B. bacteriovorus
HD100 by an in-frame deletion. Despite the inactivation of the
strB
gene,
B. bacteriovorus
was found to retain resistance to high concentrations of streptomycin. The stability of a plasmid for use in complementation experiments was also investigated, and it was determined that pMMB206 replicates autonomously in
B. bacteriovorus
. Development of this practical genetic system now facilitates the study of
B. bacteriovorus
at the molecular level and will aid in understanding the regulatory networks and gene function in this fascinating predatory bacterium.
Overexpression of the Calcineurin Target
CRZ1
Provides Freeze Tolerance and Enhances the Fermentative Capacity of Baker's Yeast
Authors: Panadero Joaquín , Hernández-López Maria José , Prieto José Antonio , Randez-Gil Francisca
Published: June 2007

Recent years have shown a huge growth in the market of industrial baker's yeasts (
Saccharomyces cerevisiae
), with the need for strains affording better performance in prefrozen dough. Evidence suggests that during the freezing process, cells can suffer biochemical damage caused by osmotic stress. Nevertheless, the involvement of ion-responsive transcriptional factors and pathways in conferring freeze resistance has not yet been examined. Here, we have investigated the role of the salt-responsive calcineurin-Crz1p pathway in mediating tolerance to freezing by industrial baker's yeast. Overexpression of
CRZ1
in the industrial HS13 strain increased both salt and freeze tolerance and improved the leavening ability of baker's yeast in high-sugar dough. Moreover, engineered cells were able to produce more gas during fermentation of prefrozen dough than the parental strain. Similar effects were observed for overexpression of Td
CRZ1
, the homologue to
CRZ1
in
Torulaspora delbrueckii
, suggesting that expression of calcineurin-Crz1p target genes can alleviate the harmful effects of ionic stress during freezing. However, overexpression of
STZ
and
FTZ
, two unrelated
Arabidopsis thaliana
genes encoding Cys
2
/His
2
-type zinc finger proteins, also conferred freeze resistance in yeast. Furthermore, experiments with Δ
cnb1
and Δ
crz1
mutants failed to show a freeze-sensitive phenotype, even in cells pretreated with NaCl. Overall, our results demonstrate that overexpression of
CRZ1
has the potential to be a useful tool for increasing freeze tolerance and fermentative capacity in industrial strains. However, these effects do not appear to be mediated through activation of known salt-responding pathways.
Characterization of a Novel Gene for Strain Typing Reveals Substructuring of
Aspergillus fumigatus
across North America
Authors: Balajee S. Arunmozhi , Tay Sun T. , Lasker Brent A. , Hurst Steve F. , Rooney Alejandro P.
Published: June 2007

Fifty-five epidemiologically linked
Aspergillus fumigatus
isolates obtained from six nosocomial outbreaks of invasive aspergillosis were subtyped by sequencing the polymorphic region of the gene encoding a putative cell surface protein, Afu3g08990 (denoted as CSP). Comparative sequence analysis showed that genetic diversity was generated in the coding region of this gene by both tandem repeats and point mutations. Each unique sequence in an outbreak cluster was assigned an arbitrary number or CSP sequence type. The CSP typing method was able to identify “clonal” and genotypically distinct
A. fumigatus
isolates, and the results of this method were concordant with those of another discriminatory genotyping technique, the
Afut1
restriction fragment length polymorphism typing method. The novel single-locus sequence typing (CSP typing) strategy appears to be a simple, rapid, discriminatory tool that can be readily shared across laboratories. In addition, we found that
A. fumigatus
isolates substructured into multiple clades; interestingly, one clade consisted of isolates predominantly representing invasive clinical isolates recovered from cardiac transplant patients from two different outbreak situations. We also found that the
A. fumigatus
isolate Af293, whose genome has been sequenced, possesses a CSP gene structure that is substantially different from those of the other
A. fumigatus
strains studied here, highlighting the need for further taxonomic study.
Coding Tandem Repeats Generate Diversity in
Aspergillus fumigatus
Genes
Authors: Levdansky Emma , Romano Jacob , Shadkchan Yona , Sharon Haim , Verstrepen Kevin J. , Fink Gerald R. , Osherov Nir
Published: June 2007

Genes containing multiple coding mini- and microsatellite repeats are highly dynamic components of genomes. Frequent recombination events within these tandem repeats lead to changes in repeat numbers, which in turn alters the amino acid sequence of the corresponding protein. In bacteria and yeasts, the expansion of such coding repeats in cell wall proteins is associated with alterations in immunogenicity, adhesion, and pathogenesis. We hypothesized that identification of repeat-containing putative cell wall proteins in the human pathogen
Aspergillus fumigatus
may reveal novel pathogenesis-related elements. Here, we report that the genome of
A. fumigatus
contains as many as 292 genes with internal repeats. Fourteen of 30 selected genes showed size variation of their repeat-containing regions among 11 clinical
A. fumigatus
isolates. Four of these genes, Afu3g08990, Afu2g05150 (
MP
-
2
), Afu4g09600, and Afu6g14090, encode putative cell wall proteins containing a leader sequence and a glycosylphosphatidylinositol anchor motif. All four genes are expressed and produce variable-size mRNA encoding a discrete number of repeat amino acid units. Their expression was altered during development and in response to cell wall-disrupting agents. Deletion of one of these genes, Afu3g08990, resulted in a phenotype characterized by rapid conidial germination and reduced adherence to extracellular matrix suggestive of an alteration in cell wall characteristics. The Afu3g08990 protein was localized to the cell walls of dormant and germinating conidia. Our findings suggest that a subset of the
A. fumigatus
cell surface proteins may be hypervariable due to recombination events in their internal tandem repeats. This variation may provide the functional diversity in cell surface antigens which allows rapid adaptation to the environment and/or elusion of the host immune system.
Binding of Human Plasminogen toBifidobacterium
Authors: Candela Marco , Bergmann Simone , Vici Manuela , Vitali Beatrice , Turroni Silvia , Eikmanns Bernhard J. , Hammerschmidt Sven , Brigidi Patrizia
Published: June 2007

Bifidobacteria constitute up to 3% of the total microbiota and represent one of the most important health-promoting bacterial groups of the human intestinal microflora. The presence ofBifidobacteriumin the human gastrointestinal tract has been directly related to several health-promoting activities; however, to date, no information about the specific mechanisms of interaction with the host is available. In order to provide some insight into the molecular mechanisms involved in the interaction with the host, we investigated whetherBifidobacteriumwas able to capture human plasminogen on the cell surface. By using flow cytometry, we demonstrated a dose-dependent human plasminogen-binding activity for four strains belonging to three bifidobacterial species:Bifidobacterium lactis,B. bifidum, andB. longum. The binding of human plasminogen toBifidobacteriumwas dependent on lysine residues of surface protein receptors. By using a proteomic approach, we identified five putative plasminogen-binding proteins in the cell wall fraction of the model strainB. lactisBI07. The data suggest that plasminogen binding toB. lactisis due to the concerted action of a number of proteins located on the bacterial cell surface, some of which are highly conserved cytoplasmic proteins which have other essential cellular functions. Our findings represent a step forward in understanding the mechanisms involved in theBifidobacterium-host interaction.
Mutations of the Quorum Sensing-Dependent Regulator VjbR Lead to Drastic Surface Modifications inBrucella melitensis
Authors: Uzureau Sophie , Godefroid Marie , Deschamps Chantal , Lemaire Julien , De Bolle Xavier , Letesson Jean-Jacques
Published: June 2007

Successful establishment of infection by bacterial pathogens requires fine-tuning of virulence-related genes. Quorum sensing (QS) is a global regulation process based on the synthesis of, detection of, and response to small diffusible molecules, calledN-acyl-homoserine lactones (AHL), in gram-negative bacteria. In numerous species, QS has been shown to regulate genes involved in the establishment of pathogenic interactions with the host.Brucella melitensisproducesN-dodecanoyl homoserine lactones (C12-HSL), which down regulate the expression of flagellar genes and of thevirBoperon (encoding a type IV secretion system), both of which encode surface virulence factors. A QS-related regulator, called VjbR, was identified as a transcriptional activator of these genes. We hypothesized that VjbR mediates the C12-HSL effects described above.vjbRalleles mutated in the region coding for the AHL binding domain were constructed to test this hypothesis. These alleles expressed intransin a ΔvjbRbackground behave as constitutive regulators both in vitro and in a cellular model of infection. Interestingly, the resultingB. melitensisstrains, unable to respond to AHLs, aggregate spontaneously in liquid culture. Preliminary characterization of these strains showed altered expression of some outer membrane proteins and overproduction of a matrix-forming exopolysaccharide, suggesting for the first time thatB. melitensiscould form biofilms. Together, these results indicate that QS through VjbR is a major regulatory system of important cell surface structures ofBrucellaand as such plays a key role in host-pathogen interactions.
Complementation Analysis of the Cold-Sensitive Phenotype of the
Escherichia coli csdA
Deletion Strain
Authors: Awano Naoki , Xu Chunying , Ke Haiping , Inoue Koichi , Inouye Masayori , Phadtare Sangita
Published: June 2007

The cold shock response of
Escherichia coli
is elicited by downshift of temperature from 37°C to 15°C and is characterized by induction of several cold shock proteins, including CsdA, during the acclimation phase. CsdA, a DEAD-box protein, has been proposed to participate in a variety of processes, such as ribosome biogenesis, mRNA decay, translation initiation, and gene regulation. It is not clear which of the functions of CsdA play a role in its essential cold shock function or whether all do, and so far no protein has been shown to complement its function in vivo. Our screening of an
E. coli
genomic library for an in vivo counterpart of CsdA that can compensate for its absence at low temperature revealed only one protein, RhlE, another DEAD-box RNA helicase. We also observed that although not detected in our genetic screening, two cold shock-inducible proteins, namely, CspA, an RNA chaperone, and RNase R, an exonuclease, can also complement the cold shock function of CsdA. Interestingly, the absence of CsdA and RNase R leads to increased sensitivity of the cells to even moderate temperature downshifts. The correlation between the helicase activity of CsdA and the stability of mRNAs of cold-inducible genes was shown using
cspA
mRNA, which was significantly stabilized in the Δ
csdA
cells, an effect counteracted by overexpression of wild-type CsdA or RNase R but not by that of the helicase-deficient mutant of CsdA. These results suggest that the primary role of CsdA in cold acclimation of cells is in mRNA decay and that its helicase activity is pivotal for promoting degradation of mRNAs stabilized at low temperature.
Transcriptional Responses of
Mycoplasma gallisepticum
Strain R in Association with Eukaryotic Cells
Authors: Cecchini Katharine R. , Gorton Timothy S. , Geary Steven J.
Published: June 2007

Mycoplasma gallisepticum
is an etiologic agent of chronic respiratory disease in chickens and infectious sinusitis in turkeys. Other than proteins important for cytadherence, few
M. gallisepticum
factors or pathways contributing to host cell interactions have been identified. In this study, an oligonucleotide-based microarray was utilized to investigate transcriptional changes in
M. gallisepticum
strain R
low
upon exposure to eukaryotic cells. Fifty-eight genes were either up- or downregulated upon exposure to MRC-5 lung fibroblasts grown in vitro, including genes encoding transport-, metabolism-, and translation-associated proteins. Twenty of the 58 regulated genes have no assigned function. These results indicate that
M. gallisepticum
regulates gene expression upon exposure to eukaryotic cells, revealing genes and pathways likely to be important for host-bacterium interaction.
A SIMPLIFICATION IN THE ESTIMATION OF “PROTHROMBIN TIME” FOR THE CONTROL OF ANTICOAGULANT THERAPY
Authors: Keyser J. W. , Payne R. B.
Published: June 2007

A modification is described which reduces considerably the amount of pipetting involved in the estimation of “prothrombin time.”

The procedure used by the authors is described in full. Particular attention is paid to the preparation and storage of the thromboplastin and to the sterilization of the citrate tubes used for the collection of specimens.
FIBRINOLYTIC AND ANTIFIBRINOLYTIC ACTIVITY IN PREGNANCY
Authors: Naidoo S. S. , Hathorn M. , Gillman T.
Published: June 2007

Fibrinolytic activity and serum antifibrinolysin were estimated in normal pregnant women, during and after labour.

The decreased fibrinolytic activity found during labour returned to non-pregnant levels within 24 hours of delivery. During the same period, the serum antifibrinolysin was rapidly diminished.

It is suggested that the post-partum increase in fibrinolytic activity to non-pregnant levels is due to alterations in the fibrinolytic system itself, as well as to changes in circulating antifibrinolysin.
THE DETERMINATION OF SERUM IRON AFTER THE INTRAVENOUS INJECTION OF IRON-DEXTRAN
Authors: Webster D.
Published: June 2007

A rapid technique for the determination of iron in serum, after the intravenous injection of iron-dextran, is presented.

Dithionite is used for the reduction of ferric to ferrous iron.

The use of a detergent solution enables protein precipitation to be omitted.

The iron reagent, 4: 7-diphenyl-1: 10-phenanthroline, and its ferrous complex are both soluble in the dilute detergent solution.

Lipaemic serum can be used without affecting the results.

The recovery of added ferric iron, as iron-dextran, is quantitative.
EFFECTS OF POSTURE ON PLASMA VOLUME AND SOME BLOOD CONSTITUENTS
Authors: Fawcett J. K. , Wynn V.
Published: June 2007

When the posture was changed from horizontal to vertical, or the reverse, the alteration in plasma volume and in the levels of haematocrit, haemoglobin, and plasma protein was much greater in patients with oedema or low plasma protein or albumin concentrations (“the pathological group”) than in patients without these abnormalities (“the control group”). This larger fluid shift, and the larger concentration changes dependent on it, are explained in terms of Starling's hypothesis.

In the control group there was scarcely any change in the total mass of intravascular plasma protein with change in posture, but in the pathological group this was often considerable. This was interpreted as indicating increased permeability of the capillaries to protein.

Attention is drawn to the influence of uncontrolled alterations in posture on biochemical and haematological measurements and a recommendation is made in order to standardize conditions before taking blood for the analysis of non-diffusible constituents.
TISSUE REACTIONS TO ASPERGILLUS IN CASES OF HODGKIN'S DISEASE AND LEUKAEMIA
Authors: Gowing N. F. C. , Hamlin Iris M. E.
Published: June 2007

Five cases of aspergillosis complicating Hodgkin's disease and leukaemia are reported. The organs involved were: lungs (all five cases), stomach (Case 3); brain and meninges (Case 4); heart, kidneys, spleen, thyroid, and liver (Case 2). Cultures ofAspergillus fumigatuswere obtained from the post-mortem tissues of three patients.

All the lesions in Case 2 were suppurative. The other four cases had non-suppurative lesions characterized by spreading coagulation necrosis with peripheral hyperaemia, exudation, and haemorrhage. Invasion and occlusion of blood vessels occurred frequently.

The various factors that may be responsible for the initiation and progression of the fungal infection are discussed. The available evidence suggests thatAspergillus fumigatuscan produce toxic metabolites which are able to cause tissue necrosis and vascular damage. In patients suffering from neoplastic conditions of the lympho-reticular system, especially if steroid hormones or radiomimetic drugs are given, spreading, necrotizing lesions can develop unchecked by antibody or cellular defences.
FOLIC ACID AND OTHER ABSORPTION TESTS IN LYMPHOSARCOMA, CHRONIC LYMPHOCYTIC LEUKAEMIA, AND SOME RELATED CONDITIONS
Authors: Pitney W. R. , Joske R. A. , Mackinnon Norma L.
Published: June 2007

An improved folic acid absorption test is described in detail.

Using the folic acid and other absorption tests, a study of intestinal function has been made in eight patients with lymphosarcoma, eight with chronic lymphocytic leukaemia, two with Hodgkin's disease, and one each with reticulum cell sarcoma, Whipple's disease, and macroglobulinaemia. It was found that laboratory evidence of intestinal malabsorption was extremely common in patients with this group of diseases.

The folic acid absorption test was the most sensitive single index of malabsorption of the tests used in this study.

Correlation between the different absorption tests was poor, and there does not appear to be a characteristic biochemical profile of intestinal function in these patients.
THE RELATION OF SERUM URIC ACID TO HAEMOGLOBIN LEVEL IN PATIENTS WITH CARDIAC AND RESPIRATORY DISEASE
Authors: Lewis J. G. , Gardner J. E.
Published: June 2007

An investigation was made of the serum uric acid in 130 male patients with long-standing cardiac or pulmonary disease. The mean serum uric acid was 4.66 mg. per 100 ml. with a standard deviation of ±0.99.

The serum uric acid increased parallel with a rise in the haemoglobin level. The coefficient of correlation was +0.5, which was nearly six times the standard error.

The frequency of hyperuricaemia (over 6 mg. per 100 ml.) was 11 times in 47 patients with a haemoglobin level above 110% as compared with twice in 83 patients when the haemoglobin level was below this figure.

The highest levels of serum uric acid were seen in patients with cyanotic congenital heart disease.

Two of the patients with hyperuricaemia gave a suggestive history of gout, and this was believed to have been caused by the secondary polycythaemia.

Serum uric acid levels were significantly higher, as were the haemoglobin concentrations, in the obese compared with the patients who were not obese.
Sterilization by dry heat
Authors: Darmady E. M. , Hughes K. E. A. , Jones J. D. , Prince D. , Tuke Winifred
Published: June 2007

The advantages and disadvantages of three forms of dry heat sterilization are discussed. In addition a fourth method, consisting of heating by infrared raysin vacuo, is described. This method is particularly suitable for instruments used in the operating theatre, since it can replace an autoclave where a supply of steam is not available. Recommended times and temperatures for dry heat sterilization are detailed, and are related to the thermal death point ofCl. tetani.The dangers of recontamination during the cooling process are discussed.
A survey of staphylococci isolated in hospital practice
Authors: Bradley J. , Meynell M. J.
Published: June 2007

In-patient and out-patient strains of coagulase-positive staphylococci were compared and showed a different phage group distribution. Group III predominated in the in-patient series and accounted for nearly all the antibiotic-resistant strains. The prevalence of phage type 80 in breast abscesses was noted. It was found that one in three coagulase-positive staphylococci isolated from hospital in-patients was sensitive to chloramphenicol and erythromycin only.
Pathological changes in temporal arteries removed from unselected cadavers
Authors: Ainsworth R. W. , Gresham G. A. , Balmforth G. V.
Published: June 2007

Progressive degenerative changes in ageing temporal arteries are described. These changes are usually severe in elderly patients, hence their presence in diagnostic biopsies provides no evidence of temporal arteritis past or present.

In two patients in the series of random necropsies examined there were changes in the temporal arteries identical with those seen in patients known to have suffered from temporal arteritis in the past; in both these cases there was, in addition a giant cell aortitis.

The distinction between healed arteritis and degenerative changes due to age in a single biopsy specimen may be difficult. Furthermore, it is possible that steroid treatment may arrest the progress of the disease so that gross intimal thickening and vascularization of the artery wall do not occur.

Giant cell arteritis is not a rare disease. Two examples were discovered in 39 random necropsies on patients over 60 years of age.
The adhesiveness of native platelets and its prevention
Authors: O'Brien J. R.
Published: June 2007

The following methods were used to measure the adhesion to various surfaces of platelets in whole blood or plasma: 1, two measurements gave an estimatein vivoof platelet adhesion to cut human capillaries; 2, platelets adhering to damaged cellsin vitrowere counted directly; 3, a highly reproducible method for estimating platelet adhesion to glass was devised; 4, the manner in which platelets adhere to each other (aggregation) was also studied.

Platelet adhesion to all these surfaces was found to be dependent upon calcium and independent of all clotting factors except that platelet aggregation is probably dependent upon thrombin. A number of drugs—mostly antimalarials, antihistaminics, and local anaesthetics—in suitable concentration inhibited adhesion. They probably form a fixed, orientated layer on glass and possibly on cells and make these surfaces unattractive to a platelet. They also stick reversibly to live cells (including platelets) altering their permeability, and they may make platelets less adhesive. Consequently the possibility of using antiadhesive drugs therapeutically to inhibit thrombus formation was considered.
The occurrence of post-gamma protein in urine: a new protein abnormality
Authors: Butler Elizabeth A. , Flynn F. V.
Published: June 2007

As a result of studying the urine proteins of 223 individuals by starch gel electrophoresis, a new urine protein fraction has been recognized. On starch gel electrophoresis at alkalinepH the new fraction moves to a position appreciably nearer the cathode than the slowest-moving γ-globulin in normal serum. A small amount of this post-γ protein was found in the urine of 46 patients with clinical proteinuria, including 19 with the Fanconi syndrome and nine with multiple myeloma.

The nature, origin, and clinical significance of post-γ protein is discussed.
Physico-chemical and immunological observations on the abnormal proteins in three patients with cryoglobulinaemia
Authors: Ellis H. A. , Stanworth D. R. , Ratcliff P.
Published: June 2007

Three new cases of cryoglobulinaemia are described, and in each case the presence of the cryoglobulin appeared to be unrelated to the clinical manifestations. Although when examined by paper electrophoresis the abnormal proteins behaved uniformly as normal gamma globulins, marked differences in nature were revealed when ultracentrifugal and immunological analyses were made. One patient had an abnormal protein which behaved both as a cryoglobulin and as a macroglobulin.
Death of an infant in hyperthermia after vaccination
Authors: Apostolov K. , Flewett T. H. , Thompson K. S.
Published: June 2007

Death following hyperpyrexia and coma of rapid onset nine days after vaccination of an infant is reported. Death appeared to be due to overwhelming vaccinial infection without encephalitis. Large amounts of virus was present in lung, spleen, bone marrow, and the vaccination site.
Tumours of salivary tissue
Authors: Cameron J. Malcolm
Published: June 2007

A clinical study of 401 cases of tumour of salivary tissue has been made and the results reported, together with a review of the literature. The histological variations of such tumours are classified and discussed.
An assessment of the anatomical factor in cor pulmonale in emphysema
Authors: Dunnill M. S.
Published: June 2007

The morbid anatomical factors in the production of right heart hypertrophy and failure in emphysema have been reviewed with reference to 44 cases studied by standard histological methods and by post-mortem pulmonary arteriography. The most important factors in raising the pulmonary vascular resistance in these cases are considered to be vascular deformity and pressure by the emphysematous spaces on the adjacent branches of the pulmonary artery. Precapillary bronchopulmonary arterial anastomoses may be of importance in those cases where areas of localized bronchiectasis are present. Intimal fibrosis of the pulmonary arterioles, destruction of the pulmonary vascular bed, and thromboembolic phenomena were thought to be of only minor importance in the production of cor pulmonale in emphysema.