bluuebunny/crossref_metadata_2025 huggingface dataset:
Salmonella isolations in abattoirs in Greece
Authors: Vassiliadis P. , Trichopoulos D. , Papadakis J. , Politi G.
Published: May 2009

The prevalence of salmonellas in drain swabs from three abattoirs of Athens was studied with the use of conventional methods of Salmonella isolation as well as with a new procedure which involves secondary enrichment from the usual selenite broth or Muller-Kauffmann's tetrathionate broth in Rappaport's medium slightly modified.

In all groups studied the secondary enrichment in Rappaport's medium led to an increase in the number of positive swabs, in the number of Salmonella serotypes, and in the total number of strains isolated.

The frequency of Salmonella isolations was higher in samples from abattoirs killing only pigs and lower in samples from abattoirs killing only cattle or only sheep.

The predominant serotype in abattoirs dealing with cattle was Salmonella tennessee, and S. typhimurium in abattoirs dealing with sheep. No predominant serotype was found in samples from abattoirs dealing mostly with pigs.

S. abony, S. drypool, S. emek, S. Indiana, S. muenchen and S. tennessee were isolated for the first time in Greece.
On the Differentiation of Proteins of Closely Related Species by the Precipitin Reaction
Authors: Welsh D. A. , Chapman H. G.
Published: May 2009

The ultimate problem underlying many applications of the precipitin test, whether it be the determination of biological relationships, the identification of blood stains and other animal traces, or the detection of adulteration in food, is the recognition of the homologous protein (antigen) and its separation from closely allied heterologous proteins. Recognising that the antiserum is the main source of the precipitate in a precipitin reaction and having regard to the exact quantitative relations of antiserum, antigen and precipitate we have been able to arrange methods for the differentiation of proteins of closely related species and, we believe, to render more accurate the diagnosis of the source of individual proteins. To take a crucial instance, by means of an antiserum prepared with hen egg-white we have been able clearly to distinguish solutions of hen egg-white from all other avian egg-whites tested, including those of the duck, quail, partridge, pheasant and ostrich. So far as we know, Nuttall and Graham Smith alone have previously been successful in differentiating homologous and heterologous avian egg-albumens, and their methods appear to be more cumbersome than ours. Incidentally we have found that our results are not only consistent inter se but consistent also with the interpretation of the precipitin reaction which our previous observations had led us to adopt.
Coli-aerogenes bacteria in soils
Authors: Taylor C. B.
Published: May 2009

The prevalence of the different types of coli–aerogenes bacteria has been determined in various soils collected from widely separated locations in the United Kingdom and in Denmark. Of the soils examined, 27% contained no coli–aerogenes organisms in 15 g. of soil tested. The number of these organisms in the positive soils was very low; only 11% had confirmed counts greater than 100 organisms/g. and 33% less than 1 organism/g.

The most prevalent organism isolated was Bacterium coli type I, whatever the location or vegetation type of the soil; intermediate type I, Bact. aerogenes type I and Bact. coli type II were the only other organisms of numerical importance. The annual application of large amounts of either farmyard or inorganic manures produces no permanently large population of coli-aerogenes organisms in soils.

Presumptive tests in MacConkey broth were unreliable, since only 6 % of the positive tubes from hill and moorland soils and 28 % from arable soils were confirmed as containing coli-aerogenes bacteria. Such discrepancies are considered to be partly due to coliform bacteria with weak lactose-fermenting properties.

It is considered that there is now sufficient experimental evidence to discredit statements that soil is the natural habitat of Bact. aerogenes or intermediate types of coli-aerogenes organism.
The Varying Epidemiology of Q Fever in the South-East Region of Great Britain II. In two Rural Areas
Authors: Marmion B. P. , Stoker M. G. P.
Published: May 2009

The epidemiology of Q fever in the residents of two rural areas, respectively, the Romney Marsh in Kent and Chatteris-Witchford rural districts in Cambridgeshire, has been studied.

In the Romney Marsh some 14 % of persons who had suffered from pneumonia or undiagnosed fever probably had Q fever. No cases of Q fever were detected in Chatteris-Witchford R.D.

Two sources of infection—sheep and infected cows' milk—were found in the Romney Marsh, and the infection of some of the cases of Q fever could be attributed to them. There was also a group of cases who were probably not infected from milk or by direct exposure to sheep. They may, however, have been indirectly infected from sheep.

The absence of Q fever in the Chatteris-Witchford area is of interest in view of the use of raw milk by a substantial proportion of the inhabitants of this area and also because of their contact with cattle. Investigation, however, failed to reveal any infection of the cattle with Rickettsia burneti.
Nutrition in the Caribbean
Authors: Aykroyd W. R.
Published: May 2009

1. In many parts of the Caribbean there is a high mortality between 6 months and 2 years due to malnutrition and gastro-enteritis. These two conditions are so closely inter-connected that they can conveniently be regarded as a single syndrome, for which the term ‘weanling diarrhoea’ has recently been suggested. The clinical picture revealed by visits to children's wards was in line with the vital statistics.

2. The prevalence of malnutrition and gastro-enteritis in infants and young children is the result of child-feeding practices characteristic of the area. The duration of breast-feeding is shorter than in Africa and Asia. After 3 months or so breast-feeding, if it does not cease altogether, becomes partial, and in general there is a steady change in the direction of less breast milk. In some territories weaning at an even earlier stage in infancy seems to result in the common occurrence of malnutrition in infants under 6 months of age.

3. The foods given to supplement or replace breast milk include processed cow's milk, starch roots and fruits and cereals. Imported processed milk supplies good quality protein otherwise lacking in the child's diet, but the use of expensive proprietory infant milk foods, out of line with family purchasing power and given in over-diluted form, is among the causes of malnutrition. The use in infant and child feeding of dried skim milk-much the cheapest kind of milk in terms of nutritive value-is increasing and this trend should be encouraged.

4. Most of the malnutrition is of the ‘marasmic’ type. Classical kwashiorkor, now comparatively rare, was seen more often 5–10 years ago.

5. It is suggested that the conventional practice of grouping deaths in the periods 0 to 1 and 1 to 4 has, in the Caribbean and other developing areas, retarded recognition of the importance of malnutrition and gastro-enteritis as the principal cause of death during and after the weaning period. The analysis of mortality statistics according to shorter age intervals is desirable.

6. Further studies and action are recommended concerned with the following: the continuing analysis of mortality and morbidity statistics to elicit relationships with malnutrition; child feeding practices in the different territories; the social and economic background of individual victims of malnutrition and of the feeding errors responsible for their condition; improvement in the treatment of malnourished children; the scope and efficiency of maternal and child health services; the distribution of dried skim milk and its extension.

7. The establishment of a Caribbean Nutrition Centre will contribute to the prevention of malnutrition and help in solving long-term problems of food supply and nutrition in the area.
Description and analysis of a simple micro-titration immune cytolytic test
Authors: Spooner R. L. , Bowden F. W. , Carpenter R. G.
Published: May 2009

A method of micro-titration for cytolytic antibodies is described. Standard drops of diluent are placed on a subdivided siliconed slide and dilutions are made by rotating a wire loop holding 1 drop of serum in each drop sequentially. One drop of a mixture of cells and complement is then added. The slide is incubated in a moist chamber for 90 min at 37° C. after which a small cover-slip is placed on each drop and the amount of cell lysis, judged by phase-contrast microscopy, is graded.

An analysis of variance of the method has been performed and the method has been found to be reliable, accurate and unbiased.

It allows accurate estimates of cytolytic activity in sera using cell concentrations of 104to 105cells per ml. Eight ten-dilution titrations can be carried out with 1 ml. of such a suspension.
The isolation of salmonellas from animal feedingstuffs
Authors: Harvey R. W. S. , Price T. H.
Published: May 2009

A technique is described for the routine isolation of salmonellas from meat and bone meal samples used in animal feedingstuffs. The technique more than doubled the number of positives obtained by an orthodox method. Identical samples were used in the trial.
Quality control tests of two salmonella enrichment media using different inocula
Authors: Harvey R. W. S. , Price T. H. , Crone P. B.
Published: May 2009

Inocula of polluted water naturally infected with salmonellas effectively distinguished six brands of selenite and six brands of tetrathionate enrichment media into satisfactory and unsatisfactory categories. Minimal inocula of pure cultures differentiated the tetrathionates, but not the selenites. Inocula of naturally infected chicken giblets suggested that there was a difference between two comparable brands of tetrathionate, but this was not statistically significant. The difference was, however, clearly demonstrated by minimal inocula of pure cultures.

Intensive investigation of two inferior tetrathionates revealed inhomogeneity in the distribution of brilliant green in one bottle of one brand. The importance of the salmonella serotype and even the colonial variant used for the pure culture inoculum was also demonstrated.
An evaluation of antiseptics used for hand disinfection in wards
Authors: Ojajärvi Juhani
Published: May 2009

The antibacterial effectiveness of hand antiseptics commonly used in wards was studied by laboratory and in-use tests and their acceptability assessed by means of a questionnaire passed to hospital staff. To determine the immediate and long-term antibacterial effects of the preparations the in-use tests were performed by groups of students. The greatest immediate reduction in bacterial counts on hands was obtained by products containing chlorhexidine. The longterm antibacterial effect was recorded with emulsions containing 3% hexachlorophane, 2% Irgasan CF3R or 4% chlorhexidine when used constantly on several consecutive days. Considerable discrepancies were recorded in the antibacterial effectiveness of some preparations when comparing laboratory and in-use test results. Therefore it is suggested that antiseptics should be tested by in-use tests which more closely resemble practical conditions before their use, or further trial, in hospital.
Isolation ofShigella sonneiby fluid media
Authors: Price T. H.
Published: May 2009

Selenite F broth prepared in the laboratory from single ingredients was found to be significantly more efficient than nutrient broth in the isolation ofShigella sonneifrom human faeces. It was more efficient than direct plating on deoxycholate citrate agar for diagnosing Sonne dysentery in a local outbreak. The difference was significant. There was, however, no significant advantage for enrichment over direct plating when stools posted from Bristol to Cardiff were examined.

Laboratory prepared selenite F broth was preferable to the same medium purchased commercially from two different firms. The product of one firm was significantly better than that of the other.

Two methods of sterilization of laboratory prepared selenite F broth were studied. Seitz filtered selenite was less inhibitory to the growth of small numbers ofShigella sonnei. Sterilization by heating in free steam for periods of 15 mm and over impaired the ability of selenite F broth to allow multiplication of small numbers ofShigella sonnei.
Radioimmunoassay for antibodies againstBrucella abortus: a new serological test for bovine brucellosis
Authors: Chappel R. J. , Williamson P. , McNaught D. J. , Dalling M. J. , Allan G. S.
Published: May 2009

A radioimmunoassay (RIA) has been developed to measure antibodies againstBrucella abortusin bovine serum and can be used in the diagnosis of bovine brucellosis. The RIA measures the amount of specific antibody of the IgG1and IgG2subclasses but is insensitive to 1gM, a characteristic which may make it more suitable than the complement fixation test (OFT) or the serum agglutination test for distinguishing infected animals from those which have been vaccinated withBr. abortusstrain 19. The RIA is not subject to prozoning or ambiguous reactions, both of which interfere with the interpretation of the CFT.
A comparison of the distribution of Clostridium botulinum in soil and in lake mud
Authors: Smith G. R. , Moryson Caroline J.
Published: May 2009

In 1975, 25 soil samples were collected from the London area. Of these, 20 were obtained 200–300 yards from 20 lakes that had been shown in 1974 to contain mud contaminated with one or more of types B, C, D and E of Clostridium botulinum. By means of a technique comparable with that used for the examination of mud, the 20 soil samples were found negative. The remaining 5 soil samples, obtained from sites that were not in close proximity to lakes, were also negative except for one that contained type B.
Studies upon the Toxicity of Putrid Food
Authors: Savage William G.
Published: May 2009

In nearly every case where canned meat or fish is condemned as unfit for human consumption, the action is based upon the physical features of the unopened tin, which are held to indicate decomposition of the contents. No studies of canned foods would therefore be complete without some detailed consideration as to the real harmfulness of such rejected foodstuffs.
An outbreak of paratyphoid fever in the UK associated with a fish-and-chip shop
Authors: Francis S. , Rowland J. , Rattenbury K. , Powell D. , Rogers W. N. , Ward L. , Palmer S. R.
Published: May 2009

An outbreak of Salmonella paratyphi B infection in the UK associated with a fish-and-chip shop is reported. The source of infection for the first three cases was believed to be a food handler who was infected overseas 6 years earlier. His wife whose faeces and urine were originally culture negative continued to run the shop but subsequently her faeces became positive on one occasion. She was considered to have been the source of two further cases, and secondary household spread of infection from these two cases resulted in one symptomatic and two asymptomatic infections. A second household contact of the proprietor also became a faecal excretor 2 months later. We recommend that food handlers living in households or in intimate contact with eases or carriers of S. paratyphi B should be put off work until all household contacts cease excreting the organism.
Restriction endonuclease characterization of resistant plasmids in Enterobacteriaceae isolated from children in the Sudan
Authors: Shears P. , Suliman G. , Hart C. A.
Published: May 2009

The investigation of plasmid similarity is an important component in the surveillance of antimicrobial resistance and in the detection of epidemic plasmids. The use of restriction endonucleases in the classification of transferable, multiply-resistant plasmids from faecal Enterobacteriaceae isolated at the Children's Emergency Hospital, Khartoum was investigated. Twenty-four transconjugant plasmids, coding for 11 different resistance patterns, each of molecular weight 62 MDa. were studied using four restriction enzymes;PstI,EcoR I,HindIII andAraII. Fifteen different digest profiles were obtained. Restriction profiles discriminated between plasmids with differing resistance patterns and demonstrated homology of plasmids with common resistance patterns. Restriction endonuclease digest patterns provide a potentially rapid and reproducible method of plasmid classification, that could contribute towards surveillance systems in tropical countries with a high prevalence of antimicrobial resistance.
Bismuth subsalicylate in the prevention of colonization of infant mice withCampylobacter jejuni
Authors: Hänninen M. L.
Published: May 2009

Infant mice were used for the evaluation of the efficacy of bismuth subaslicylate (BSS) in the prevention the growth ofCampylobacter jejuniin the intestine. The MIC90of tenC. jejunistrains was 900 μg/ml. Of three dosage regimens tested, continuous treatment before and after the bacterial challenge, mimicking the way BSS is used in the prevention of traveller's diarrhoea, was the most effective. Growth inhibition was dose dependent; the high dose of 2000 μg per day was more effective than 300 μg per day. After cessation of treatment, campylobacter counts increased to the same level as in the control animals.
Incrimination of an environmental source of a case of Legionnaires' disease by pyrolysis mass spectrometry
Authors: Sisson P. R. , Freeman R. , Lightfoot N. F. , Richardson I. R.
Published: May 2009

Following a case of Legionnaires' diseaseLegionella pneumophilaof the same serogroup was isolated from the hot water system of the hotel which had been epidemiologically implicated as the source of the infection. Pyrolysis mass spectrometry (PyMS) was used to compare 11 isolates from the hotel water sample with the patient's strain. Epidemiologically unrelated isolates, both clinical and environmental, of the same serogroup and monoclonal antibody type ofL. pneumophilawere included in the same analysis, together with relevant reference strains. The patient strain was shown to be indistinguishable from seven of the hotel water isolates, but clearly different from other unrelated clinical isolates, the reference strains and some of the other environmental isolates. PyMS is a rapid and cheap method for inter-strain comparison forL. pneumophila.
Campylobacter enteritis in Saudi Arabia
Authors: Zaman R.
Published: May 2009

A 12-month survey on the incidence of campylobacter infection in 1217 patients with diarrhoea was carried out in Jeddah, Saudi Arabia. Campylobacters were isolated from 55 (4·5%) patients, second in prevalence to salmonellas (6·2%). Shigellas were isolated from 4·2% of patients. Campylobacter isolation rates were high in children of all ages, as well as in young adults (36·5% of all isolates were from adults aged 20–39 years). Isolation rates peaked in September and November. Analysis of the results showed that 69% wereCampylobacter jejuni(mostly biotype IV) and 31%C. coli. Serogroups 5 and 23 (Penner scheme) and phage type 125 (Preston scheme) were most frequently isolated. Resistance to erythromycin and tetracycline was observed in 7·3 and 32·7% of the isolates. Campylobacters are an important cause of bacterial enteritis in Saudi Arabia, both in adults and in children, and should be sought routinely.
The influence of temperature on the behaviour of mixed bacterial contamination of the shell membrane of the hen's egg
Authors: Dolman J. , Board R. G.
Published: May 2009

The inner membrane of the air cell of hens' eggs was inoculated with Pseudomonas putida, Staphylococcus xylosus, Enterococcus faecalis, Escherichia coli and Salmonella enteitidis.The first mentioned eventually dominated the contamination of the albumen of eggs stored at 4, 15, and 20 °C. The last mentioned did so in eggs stored at 37 °C. The interval between inoculation of the membrane and gross contamination of the albumen was markedly influenced by site of contamination relative to yolk movement.
Phylogenetic and epidemiological analysis ofNeisseria meningitidisusing DNA probes
Authors: Ni H. , Knight A. I. , Cartwright K. A. V. , McFadden J. J.
Published: May 2009

The genetic relationships between various serotypes and serogroups of meningococcal strains were investigated by restriction fragment-length polymorphism (RFLP) analysis using a number of random DNA probes and a probe containing a truncated copy of the meningococcal insertion sequence IS1106. The data were used to estimate genetic distance between all pairs of strains and to construct phylogenetic trees for meningococcal strains. B15: P1.16R strains isolated from cases of systemic meningococcal disease in two health districts with a high incidence of disease were clonal in contrast to similar strains from cases occurring in other parts of the UK. Strains from these areas, which contain a similar genomic deletion, were found to be derived from two distinct lineages within the B15: P1.16R phylogenetic group. RFLP data demonstrated that present serological typing systems for the meningoccus do not necessarily reflect true genetic relationships.
Community-based study of the incidence of gastrointestinal diseases in The Netherlands
Authors: Hoogenboom-Verdegaal A. M. M. , De Jong J. C. , During M. , Hoogenveen R. , Hoekstra J. A.
Published: May 2009

The incidence of gastrointestinal diseases was studied in a community-based study in four regions of The Netherlands. Two grades of severity were distinguished − 1: diarrhoea or vomiting and at least 2 additional symptoms within the period of 1 week, and 2: diarrhoea or vomiting and at least 2 additional symptoms occurring on the same day lasting at least 2 days within the period of 1 week. The incidence of gastrointestinal episodes was calculated to be 630 for grade 1 and 180 for grade 2 disease per 1000 person-years, after correction for age and sex. The incidence was higher for women than for men (relative risk 1·25) and lower for those in the 19–64-year-old age group when compared to those younger or older (relative risk 0·75 and 0·40. respectively). Independent of the degree of severity of the symptoms, about 20% of the patients had consulted a general practitioner, about half in person and half by telephone. It is concluded that community studies are essential to assess the real incidence of gastrointestinal diseases in the population.
Survey on the distribution of the gene 4 alleles of human rotaviruses by polymerase chain reaction
Authors: Wu H. , Taniguchi K. , Wakasugi F. , Ukae S. , Chiba S. , Ohseto M. , Hasegawa A. , Urasawa Tomoko , Urasawa Shozo
Published: May 2009

The presence of six gene 4 alleles (or VP4 genotypes) in human rotaviruses has been recognized. Using 16 representative cultivable human rotavirus strains, we confirmed the specificity of VP4 genotyping by polymerase chain reaction (PCR) using the nested oligonucleotides specific to each of the four representative gene 4 alleles. Using the PCR. we surveyed the gene 4 alleles of 199 human rotaviruses in stools collected in Japan and Thailand. Strains with the gene 4 allele, corresponding to P1A serotype. were shown to be the most prevalent, but two strains with P2 gene 4 allele and one strain with P3 gene 4 allele were detected in Thailand and in Japan, respectively.
Clonal dissemination of two MRSA strains in Germany
Authors: Witte W. , Cuny C. , Braulke C. , Heuck D.
Published: May 2009

Clonal dissemination of two different MRSA strains, both clumping factor negative, has been observed in Germany for more than a year. Both strains possess the mec-A determinant and each exhibits a characteristic genomic DNA fragment pattern. One strain has spread in the north, the other in the south-west of Germany.

Intensive care units are mainly affected by MRSA-infections and probably play a special role in further intra- and inter-hospital spread.
Evaluation of live attenuated measles vaccines prepared in human diploid cells for reimmunization
Authors: Mirchamsy H. , Shafyi A. , Nazari P. , Ashtiani M. P. , Sassani A.
Published: May 2009

Two live attenuated measles vaccines developed in baby calf kidney cells, a similar vaccine produced in chick embryo chorioallantoic cells and five vaccines prepared from human diploid cells (HDC) have been studied by subcutaneous injection in groups of susceptible and immune children in three field trials. The results indicated that the vaccine developed in chick embryo cells which caused mild clinical reactions, had induced a lower seroprotection rate in susceptible children and only a low rise in hemagglutination-inhibition (HI) antibody titre in previously immunized children. The serological responses induced by vaccines developed in HDC or in calf kidney cells were satisfactory in both susceptible and immune children. The superiority of HDC grown measles vaccine for revaccination is discussed.
Serological response of chickens toSalmonella enteritidisinfection
Authors: Chart H. , Rowe B. , Baskerville A. , Humphrey T. J
Published: May 2009

Fifty-eight sera, from 29 chickens originating from two layer flocks known to be naturally infected withSalmonella enteritidisphage type (PT) 4, were examined for antibodies toS. enteritidis. Using the techniques of immunoblotting and ELISA, antibodies to the lipopolysaccharide (LPS) ofS. enteritidiswere detected in 43 of 58 sera. Antibodies were of the IgG class and bound to the S. enteritidis LPS antigen 0=12. Bacterial agglutination reactions using whole-cell preparations ofS. enteritidisandS. pullorum, correlated with anti-LPS antibody reactions as detected by immunoblotting and ELISA. A rapid means of screening chicken sera for antibodies to the LPS ofS. enteritidisas an indicator of infection is discussed.
Detection of novel trimethoprim resistance determinants in the United Kingdom using biotin–labelled DNA probes
Authors: Towner K. J. , Carter G. I. , Young H.- K. , Amyes S. G. B.
Published: May 2009

Two collections of trimethoprim R plasmids, isolated from strains ofEscherichia coliduring 1978–83 and 1987–8 respectively, were retrospectively screened with specific biotinylated DNA probesfor the presence of genes encoding particular DHFR enzymes. The results confirmed that the type I DHFR gene was the predominant plasmid-encoded gene conferring trimethoprim resistance in strains ofE. colifrom the Nottingham area of the UK, but indicated that genes encoding the more recently recognized types of DHFR enzymes haappeared in the bacterial gene pool and could be recognized with increased frequency in the latter plasmid collection. Thiswasparticularly true of the type IIIa and type VII enzymes which together accounted for 27 % of the trimethoprim R plasmid examined in 1987–8.
Characterization of rotavirus electropherotypes excreted by symptomatic and asymptomatic infants
Authors: Fernández J. , Sandino A. M. , Pizarro J. , Avendaño L. F. , Pizarro J. M. , Spencer E.
Published: May 2009

Human rotavirus isolates from 1100 stool samples were analyzed by polyacrylamide gel electrophoresis, and 48 different migration patterns were detected. Heterogeneity in the migration of segment 10 was observed in both long and short electropherotypes in which three long and two short patterns were identified. In spite of these variations all short and long electropherotypes were subgrouped by enzyme immunoassay as subgroups I and II respectively. Mixed infections were detected in 17% of cases and the subgrouping correlated with the corresponding electropherotypes. The same electropherotypes were present in severe, mild and asymptomatic cases and no electropherotype was particularly associated with greater virulence. Furthermore, the electropherotypes isolated from nosocomial asymptomatic cases were the same as those detected from those admitted with severe diarrheoa. It seems unlikely that electropherotyping can be used to identify more virulent strains of rotavirus.
Molecular subtyping by genome and plasmid analysis ofCampylobacter jejuniserogroups O1 and O2 (Penner) from sporadic and outbreak cases of human diarrhoea
Authors: Fayos A. , Owen R. J. , Hernandez J. , Jones C. , Lastovica A.
Published: May 2009

Ribosomal RNA gene patterns, randomly amplified polymorphic genomic DNA (RAPD) profiles and plasmid profiles were used to discriminate between 28 strains ofCampylobacter jejuniserogroups O1 and O2 (Penner). Most isolates were biotype I (Lior). The strains were representative isolates from a UK school outbreak of enteritis (7 cases) and from 21 sporadic human cases of enteritis in 4 countries. The molecular techniques discriminated to various degrees between strains in each of the serogroups. The outbreak strains were homogeneous in most molecular features but a variety of types was detected amongst the isolates from the sporadic cases. Five groups of two or more strains with identical ribopatterns were identified and within each, strains from different patients were homogenous with respect to serogroup. RAPD profile typing based on numerical analysis generally matched ribotyping. Plasmid profiling overall gave least discrimination but was useful in separating some strains similar in other features. We concluded that optimal discrimination ofC. jejunicould best be achieved using a combination of phenotypic and genotypic properties.HaeIII ribotyping was the single most discriminatory and reproducible technique investigated. Several strains ofC. jejunifrom sporadic infections had similar molecular profiles which have potential for general typing purposes.
Correlation between esterase electrophoretic polymorphism and virulence–associated traits in extra–intestinal invasive strains ofEscherichia coli
Authors: Goullet Ph. , Picard B. , Contrepois M. , Rycke J. De , Barnouin J.
Published: May 2009

The electrophoretic variations of carboxylesterase B and of esterases A, C and I, the presence of mannose resistant haemagglutinin, α–haemolysin, cytotoxic necrotizing factor type 1 (CNF1) and certain O antigens were compared in 150 strains ofEscherichia coliresponsible for extra-intestinal infections. Electrophoretic mobilities of outer membrane proteins (OMP) were also studied for strains belonging to O4, O6, O7, O8 and O75 serogroups. Fast migrating allozymes of carboxylesterase B (pattern B1) were correlated with slow migrating allozymes of esterase C, serogroups O7 and O8, lack of virulence factor, and particular OMP patterns, whereas slow migrating allozymes of carboxylesterase B (pattern B2) were correlated with fast migrating allozymes of esterase C, serogroups O2, O4, O6, O18 and O75, virulence factor production, and distinct OMP patterns. Allozymes of esterases A and I were not clearly correlated with the distribution of virulence factors. The pattern B2was more strongly associated with CNF1 than with α–haemolysin and mannose resistant haemagglutinin. These results substantiate the view that the electrophoretic pattern B2of carboxylesterase B identified most of the highly pathogenic strains implicated in extra-intestinal infection of humans.
Application of pulsed field gel electrophoresis to the 1993 epidemic of whooping cough in the UK
Authors: Syedabubakar S. N. , Matthews R. C. , Preston N. W. , Owen D. , Hillier V.
Published: May 2009

The purpose of this study was to DNA fingerprint the majority (64 %) of isolates received at the Pertussis Reference Laboratory during the 1993 whooping cough epidemic by pulsed field gel electrophoresis of Xba I - generated restriction digests. Two DNA restriction patterns, types 1 and 3, predominated (40% and 23%. respectively, of 180 isolates) but type 2, identified in a previous study was notably absent. Twenty-one new DNA types occurred (24% of isolates), some being atypical as bands 155–230 kb were no longer conserved, but there was no statistically significant difference in their incidence in the upswing (June-September) compared to the downswing (October-December) phase of the epidemic. There was a relatively high proportion of new types, compared to type 1. at the peak (September). About 50% of isolates received were from the North Western Region, where 44% of isolates were DNA type 1. Whereas only 1 out of 10 isolates from Scotland were of this type, suggesting some geographic variation. Statistically significant findings included a higher proportion of isolates from female patients (P < 0·01), most marked in the 12–24 months age group (P < 0·05); a higher proportion of infants under 12 months requiring hospital admission compared to older children (P < 0·05); and a greater number of isolates from unvaccinated children (P < 0·01). Analysis of serotype according to four age groups (under 3 months, 3–12 months, 12–24 months and above 2 years) showed statistically significant differences (P < 0·05) with a noticeably lower proportion (38%) of serotype 1,3 in 3–12 months age group and higher prevalence (74%) of serotype 1,3 in the 12–24 months age group. There was no correlation between DNA type and serotype.
Recent trends in the numerical solution of retarded functional differential equations
Authors: Bellen Alfredo , Maset Stefano , Zennaro Marino , Guglielmi Nicola
Published: May 2009

Retarded functional differential equations (RFDEs) form a wide class of evolution equations which share the property that, at any point, the rate of the solution depends on a discrete or distributed set of values attained by the solution itself in the past. Thus the initial problem for RFDEs is an infinite-dimensional problem, taking its theoretical and numerical analysis beyond the classical schemes developed for differential equations with no functional elements. In particular, numerically solving initial problems for RFDEs is a diffcult task that cannot be founded on the mere adaptation of well-known methods for ordinary, partial or integro-differential equations to the presence of retarded arguments. Indeed, efficient codes for their numerical integration need speciffc approaches designed according to the nature of the equation and the behaviour of the solution.

By defining the numerical method as a suitable approximation of the solution map of the given equation, we present an original and unifying theory for the convergence and accuracy analysis of the approximate solution. Two particular approaches, both inspired by Runge–Kutta methods, are described. Despite being apparently similar, they are intrinsically different. Indeed, in the presence of speciffc types of functionals on the right-hand side, only one of them can have an explicit character, whereas the other gives rise to an overall procedure which is implicit in any case, even for non-stiff problems.

In the panorama of numerical RFDEs, some critical situations have been recently investigated in connection to speciffc classes of equations, such as the accurate location of discontinuity points, the termination and bifurcation of the solutions of neutral equations, with state-dependent delays, the regularization of the equation and the generalization of the solution behind possible termination points, and the treatment of equations stated in the implicit form, which include singularly perturbed problems and delay differential-algebraic equations as well. All these issues are tackled in the last three sections.

In this paper we have not considered the important issue of stability, for which we refer the interested reader to the comprehensive book by Bellen and Zennaro (2003).
PROGESTERONE AND THE CONTROL OF HUMAN PREGNANCY AND PARTURITION
Authors: MESIANO SAM , WELSH TONI
Published: May 2009

Almost 80 years ago George Corner and colleagues provided the first evidence that progesterone maintains pregnancy and that it does so, at least in part, by promoting myometrial relaxation. In the 1950s, Arpad Csapo proposed the “progesterone block hypothesis”, which posits that progesterone maintains pregnancy by promoting myometrial relaxation and that its withdrawal initiates a cascade of hormonal interactions that transforms the myometrium to a highly contractile state leading to the onset of labour. Csapo later proposed that contractility of the pregnant myometrium is determined by the balance between relaxation induced by progesterone and contraction induced by a cohort of signals including oestrogens, uterine distention and stimulatory uterotonins such as prostaglandins (PGs) and oxytocin (OT). According to this “seesaw” hypothesis, progesterone promotes myometrial relaxation by directly inducing relaxation and/or by inhibiting the production of, or myometrial responsiveness to, stimulatory uterotonins. These landmark concepts, though derived from studies of experimental animals, form the foundation for current understanding of progesterone's role in the physiology of human pregnancy. Remarkable progress has been made over the last 20–30 years in understanding the signal transduction pathways through which steroid hormones affect target cells. This knowledge has broadened the scope of Csapo's original paradigms and we are now beginning to unravel the specific signaling pathways and molecular interactions by which progesterone affects human myometrium and how its actions are controlled at the functional level. This is important for the development of progestin-based therapeutics for the prevention or suppression of preterm labour and preterm birth. Here we review recent progress in understanding the mechanisms by which progesterone sustains pregnancy and in particular how it promotes myometrial relaxation, how its relaxatory actions are nullified at parturition, and the hormonal interactions that induce progesterone withdrawal to determine the timing of human birth.
Radial evolution of nonthermal electron populations in the low‐latitude solar wind: Helios, Cluster, and Ulysses Observations
Authors: Štverák Štěpán , Maksimovic Milan , Trávníček Pavel M. , Marsch Eckart , Fazakerley Andrew N. , Scime Earl E.
Published: May 2009

We have performed a statistical study of a substantial amount of solar wind electron velocity distribution functions (eVDFs). In our data set, we combine measurements acquired onboard three spacecrafts (Helios, Cluster II, and Ulysses) in the low ecliptic latitudes covering the heliocentric distance from 0.3 up to 4 AU. In this study, we focus on the nonthermal properties of the measured eVDFs in both the slow and the fast solar wind regimes. The aim of the present study is (1) to provide, for the first time, an analytical model to fit separately all three components of the solar wind eVDFs (i.e., the core, the halo, and the strahl) and (2) to study the fractional densities of the three electron components and also the non‐Maxwellian character of the high‐energy eVDF tails as a function of the radial distance from the sun. Basically, our study is incremental to the previous studies of the fast solar wind and primarily extends their conclusions on a large number of slow wind observations in the ecliptic plane. We confirm that the halo and the strahl relative densities vary in an opposite way. The relative number of strahl electrons is decreasing with radial distance, whereas the relative number of halo electrons is increasing. The fractional density of the core population remains roughly constant. These findings suggest that there are mechanisms in the solar wind that scatter the strahl electrons into the halo. Also, we find that the relative importance of the nonthermal electrons in the fast solar wind is slightly higher compared to the slow wind.
Analysis of Polar‐orbiting Operational Environmental Satellite NOAA‐14 MSU and NOAA‐15 AMSU‐A relative measurement biases for climate change detection
Authors: Iacovazzi Robert A. , Cao Changyong , Boukabara Sid‐Ahmed
Published: May 2009

In extending microwave sounding unit (MSU) brightness temperature (Tb) time series to Advanced MSU Series‐A (AMSU‐A) measurements, small discrepancies of channel frequency center and bandwidth between these two instruments can introduce Tb biases between them. In this study, the Microwave Integrated Retrieval System (MIRS), which includes the Community Radiative Transfer Model (CRTM), has been used to estimate, and then remove, this bias component from total Tb biases inferred between NOAA‐14 MSU and NOAA‐15 AMSU‐A measurements using the simultaneous nadir overpass (SNO) method. Analysis results indicate a significant Tb bias of about 0.4 K between the NOAA‐14 MSU and NOAA‐15 AMSU‐A 50.3‐GHz channel observations. Meanwhile, the other MSU and AMSU‐A channel pairs have frequency mismatches that lead to seasonal‐ and hemispheric‐dependent Tb biases that can be larger than 1 K. Subtracting CRTM‐estimated Tb biases related to frequency mismatch from SNO‐deduced total Tb biases removes most seasonal‐ and hemispheric‐dependent Tb biases, but some significant residual biases with magnitudes of about 0.4 K or less remain. These adjusted SNO‐inferred Tb biases are attributed to a mix of uncaptured frequency‐difference related, and calibration related, Tb biases. These two bias types are not separately quantified here, owing to indefinable uncertainties in the frequency‐difference related Tb bias estimates. Thus techniques applied in this study to estimate calibration‐related Tb biases between NOAA‐14 MSU and NOAA‐15 AMSU‐A instruments can be useful in creating long‐term temperature time series using NOAA microwave sounders, but a means to evaluate the indefinable uncertainties of frequency‐difference related Tb bias estimates needs to be developed.
Nitrate variability in hydrological flow paths for three mid‐Appalachian forested watersheds following a large‐scale defoliation
Authors: Riscassi Ami L. , Scanlon Todd M.
Published: May 2009

Nitrate (NO3−) leakage from forested watersheds due to disturbance is a well documented but not well understood process that can contribute to the degradation of receiving waters through eutrophication. Several studies have shown that large‐scale defoliation and deforestation events in small forested watersheds in the eastern United States cause immediate and dramatic increases in NO3− flux to steams, with large differences in recovery time. Water quality and discharge data collected from 1992 to 2004 following a large‐scale gypsy moth defoliation were used to investigate hydrological controls on long‐term NO3− leakage from three forested watersheds in Shenandoah National Park, Virginia. During storm events, a conventional two‐component hydrograph separation in conjunction with an inverse solution technique was employed to determine the concentrations of NO3− in groundwater and soil water. Following defoliation, groundwater NO3− concentrations declined exponentially with a distinct seasonal pattern. A rank‐order relationship between the rate constants associated with the exponential declines in groundwater NO3− concentrations and groundwater recession constants indicates a hydrological control on long‐term watershed recovery for these defoliated systems. Comparisons to deforested systems in Hubbard Brook, New Hampshire, and Coweeta, North Carolina, indicate hydrological controls are similarly present. Biogeochemical differences, however, need to be considered to account for the more attenuated recovery observed in defoliated systems. No long‐term trend was found in the model‐derived soil water NO3− concentrations, which suggests the presence of some form of rate limitation on the transformation of the nitrogen pool introduced during the disturbance and/or reduced nutrient uptake due to tree mortality.
Coupled greenhouse warming and deep‐sea acidification in the middle Eocene
Authors: Bohaty Steven M. , Zachos James C. , Florindo Fabio , Delaney Margaret L.
Published: May 2009

The Middle Eocene Climatic Optimum (MECO) is an enigmatic warming event that represents an abrupt reversal in long‐term cooling through the Eocene. In order to further assess the timing and nature of this event, we have assembled stable isotope and calcium carbonate concentration records from multiple Deep Sea Drilling Project and Ocean Drilling Program sites for the time interval between ∼43 and 38 Ma. Revised stratigraphy at several sites and compilation of δ18O records place peak warming during the MECO event at 40.0 Ma (Chron C18n.2n). The identification of the δ18O excursion at sites in different geographic regions indicates that the climatic effects of this event were globally extensive. The total duration of the MECO event is estimated at ∼500 ka, with peak warming lasting <100 ka. Assuming minimal glaciation in the late middle Eocene, ∼4°–6°C total warming of both surface and deep waters is estimated during the MECO at the study sites. The interval of peak warming at ∼40.0 Ma also coincided with a worldwide decline in carbonate accumulation at sites below 3000 m depth, reflecting a temporary shoaling of the calcite compensation depth. The synchroneity of deep‐water acidification and globally extensive warming makes a persuasive argument that the MECO event was linked to a transient increase in atmospheric pCO2. The results of this study confirm previous reports of significant climatic instability during the middle Eocene. Furthermore, the direct link between warming and changes in the carbonate chemistry of the deep ocean provides strong evidence that changes in greenhouse gas concentrations exerted a primary control on short‐term climate variability during this critical period of Eocene climate evolution.
A Bayesian joint probability modeling approach for seasonal forecasting of streamflows at multiple sites
Authors: Wang Q. J. , Robertson D. E. , Chiew F. H. S.
Published: May 2009

Seasonal forecasting of streamflows can be highly valuable for water resources management. In this paper, a Bayesian joint probability (BJP) modeling approach for seasonal forecasting of streamflows at multiple sites is presented. A Box‐Cox transformed multivariate normal distribution is proposed to model the joint distribution of future streamflows and their predictors such as antecedent streamflows and El Niño‐Southern Oscillation indices and other climate indicators. Bayesian inference of model parameters and uncertainties is implemented using Markov chain Monte Carlo sampling, leading to joint probabilistic forecasts of streamflows at multiple sites. The model provides a parametric structure for quantifying relationships between variables, including intersite correlations. The Box‐Cox transformed multivariate normal distribution has considerable flexibility for modeling a wide range of predictors and predictands. The Bayesian inference formulated allows the use of data that contain nonconcurrent and missing records. The model flexibility and data‐handling ability means that the BJP modeling approach is potentially of wide practical application. The paper also presents a number of statistical measures and graphical methods for verification of probabilistic forecasts of continuous variables. Results for streamflows at three river gauges in the Murrumbidgee River catchment in southeast Australia show that the BJP modeling approach has good forecast quality and that the fitted model is consistent with observed data.
A new syringe pump apparatus for the retrieval and temporal analysis of helium in groundwaters and geothermal fluids
Authors: Barry P. H. , Hilton D. R. , Tryon M. D. , Brown K. M. , Kulongoski J. T.
Published: May 2009

We present details of a newly designed syringe pump apparatus for the retrieval and temporal analysis of helium (SPARTAH). The device is composed of a commercially available syringe pump connected to coils of Cu tubing, which interface the syringe and the groundwater or geothermal wellhead. Through test deployments at geothermal wells in Iceland and California, we show that well fluids are drawn smoothly, accurately, and continuously into the Cu tubing and can be time‐stamped through user‐determined operating parameters. In the laboratory, the tubing is sectioned to reveal helium (He) characteristics of the fluids at times and for durations of interest. The device is capable of prolonged deployments, up to 6 months or more, with minimal maintenance. It can be used to produce detailed time series records of He, or any other geochemical parameter, in groundwaters and geothermal fluids. SPARTAH has application in monitoring projects assessing the relationship between external transient events (e.g., earthquakes) and geochemical signals in aqueous fluids.