bluuebunny/crossref_metadata_2025_split huggingface dataset:
The seasonal and diurnal activities of individual sheep ticks (Ixodes ricinus L.)
Authors: Lees A. D. , Milne A. 
Published: June 2009

1. Activity in Ixodes ricinus was studied by laying down newly emerged ticks in natural clumps of vegetation from which all hosts (with the possible exception of ‘mice’) were excluded. After a period of quiescence the ticks climbed to the ‘active’ position at the vegetation tips. Activity was assessed either by simple observation (in adults which were marked individually) or by ‘brushing’ the vegetation with the hands (nymphs and larvae). 52 % of the adults and 44 % of the nymphs were recovered.2. The seasonal activity behaviour was followed in three series of ticks set out during May, July and October 1945. The results were used in interpreting the time relations of seasonal activity in ‘wild’ populations. The timing of the activity cycle appears to be largely determined by the availability of unfed ticks rather than by the prevailing meteorological conditions.3. The diurnal pattern of behaviour in active ticks was closely examined during a 24 hr. period. Many remained at the tips without moving. The others began or ended a phase of activity by night or by day; but among these, the proportion ending a phase at night was significantly greater. This is the main reason for the previously reported diurnal fluctuation of activity in a tick population.4. Two hundred and seven adult ticks spent, on an average, a total of 9 days at the vegetation tips (individual limits 1 and 54 days). This activity was spread over an ‘active period’ (interval between first and last appearances) averaging 30 days. Very active ticks rarely remained continuously at the tips. The mean number of visits to the tips was 4 (limits 1 and 19), each lasting for an average of 2·5 days. Where long spells of activity alternate with short periods of quiescence, the behaviour is probably regulated by the humidity reaction, the quiescent phase providing an opportunity for restoring the depleted water balance.5. Newly moulted adult ticks possess reserves of fat adequate for many months of quiescence. During activity these reserves are exhausted in a few weeks or even days. Duration of survival mainly depended on whether the onset of activity was immediate or delayed. Some adults remained quiescent for 1 year before becoming active for the first time.6. Several types of orientations were observed in the field. In attaining the position at the tips favourable for encountering a host, the gravity response (upward-turning near the tip) is of major importance. The tick avoids wind and direct sunlight by sheltering behind its supporting stem. In sensing the approach of a ‘host’ (the observer's finger) the perception of eddies of warm air is particularly significant. The response (questing, then orientation) is elicited much less readily if the stimulus is applied from the leeward.
Egyptian fever of cattle
Authors: Daubney R. , Said M. Sami 
Published: June 2009

The disease, Egyptian fever of cattle, has been observed at the Serum Institute, Abbassiah, in Cyrenaican and Cyprus cattle, and less frequently in native Egyptian cattle. The responsible Theileria has been determined as T. annulata (Dzchunkowsky & Luhz, 1904), and both natural and experimental transmission has been demonstrated with Hyalomma excavatum Koch 1844, of Delpy (1949b).H. excavatum in Egypt is a three-host tick, which hibernates during the winter months in the walls of buildings in the engorged nymphal and fasting adult stages. Transmission has been effected with nymphae and adults, infected in each case by feeding the preceding stage on reacting or recovered cattle. On no occasion has infection been observed to pass through the egg to the larval stage. Infection can also be transmitted by inoculation of the blood of a reacting animal in which schizonts are demonstrable.
Number, Form, Content: Hume's Dialogues, Number Nine
Authors: Fendt Gene 
Published: June 2009

AbstractThis paper's aim is threefold. First, I wish to show that there is an analogy in section nine that arises out of the interaction of the interlocutors; this analogy is, or has, a certain comic adequatic to the traditional (e.g. Aquinas's) arguments about proofs for the existence of God. Second, Philo's seemingly inconsequential example of the strange necessity of products of 9 in section nine is a perfected analogy of the broken arguments actually given in that section, destroying Philo's earlier arguments. Finally, I raise the question of the designer's intent in creating such a humourous piece.
Enhancing MEDLINE document clustering by incorporating MeSH semantic similarity
Authors: Zhu Shanfeng , Zeng Jia , Mamitsuka Hiroshi 
Published: June 2009

AbstractMotivation: Clustering MEDLINE documents is usually conducted by the vector space model, which computes the content similarity between two documents by basically using the inner-product of their word vectors. Recently, the semantic information of MeSH (Medical Subject Headings) thesaurus is being applied to clustering MEDLINE documents by mapping documents into MeSH concept vectors to be clustered. However, current approaches of using MeSH thesaurus have two serious limitations: first, important semantic information may be lost when generating MeSH concept vectors, and second, the content information of the original text has been discarded.Methods: Our new strategy includes three key points. First, we develop a sound method for measuring the semantic similarity between two documents over the MeSH thesaurus. Second, we combine both the semantic and content similarities to generate the integrated similarity matrix between documents. Third, we apply a spectral approach to clustering documents over the integrated similarity matrix.Results: Using various 100 datasets of MEDLINE records, we conduct extensive experiments with changing alternative measures and parameters. Experimental results show that integrating the semantic and content similarities outperforms the case of using only one of the two similarities, being statistically significant. We further find the best parameter setting that is consistent over all experimental conditions conducted. We finally show a typical example of resultant clusters, confirming the effectiveness of our strategy in improving MEDLINE document clustering.Contact: zhushanfeng@gmail.comSupplementary information: Supplementary data are available at Bioinformatics online.
Our changing oceans: conclusions of the first International Symposium on the Effects of climate change on the world's oceans
Authors: Valdés Luis , Peterson William , Church John , Brander Keith , Marcos Marta 
Published: June 2009

Abstract
Valdés, L., Peterson, W., Church, K., and Marcos, M. 2009. Our changing oceans: conclusions of the first International Symposium on the Effects of climate change on the world's oceans. – ICES Journal of Marine Science, 66: 1435–1438.
Structural and stereospecific requirements for the nucleoside-triggered germination of Bacillus cereus spores
Authors: Senesi Sonia , Cercignani Giovanni , Freer Giulia , Batoni Giovanna , Barnini Simona , Ota Fusao 
Published: June 2009

Summary
A selection of adenosine analogues was tested for their ability to trigger germination of Bacillus cereus NCIB 8122 spores. The germination-inducing activity was governed by the structural properties of the sugar rather than the base moieties of the nucleosides. Among the sugar-modified analogues, only those containing a 2′-deoxy-D-ribose moiety promoted spore germination. Requirements for a specific molecular structure of the base were not clearly identified, although the highest activity was observed when substituents were inserted at position 6 of the purine ring. All the base-modified analogues, even those such as coformycin and 2′-deoxycoformycin with an expanded base ring, retained the germination-inducing activity of adenosine. However, of the two 2′-deoxycoformycin diastereoisomers characterized by an asymmetric carbon atom at position 8 of the homopurine ring, only the 8 S-isomer induced germination, thus indicating that stereospecific configuration of the inducer, at least in the case of 2′-deoxycoformycin, appears to be essential for the initiation of spore germination. The differences in the germination-inducing activity of the various analogues tested were not affected significantly by spore activation at different temperatures, although the higher the activation temperature, the lower was the concentration of each analogue required for maximum germination.
Caesium accumulation and interactions with other monovalent cations in the cyanobacterium Synechocystis PCC 6803
Authors: Avery Simon V. , Codd Geoffrey A. , Gadd Geoffrey M. 
Published: June 2009

SummaryGrowth ofSynechocystisPCC 6803 in BG-11 medium supplemented with 1 mM-CsCl resulted in intracellular accumulation of Cs+to a final level of approximately 510 nmol (109cells)-1after incubation for 10 d. The doubling time was increased by 64% and the final cell yield was decreased by 70% during growth in the presence of Cs+as compared to growth in control BG-11 medium. When the total monovalent cation concentration of the medium was doubled by adding either K+or Na+, levels of accumulated Cs+were decreased by approximately 50% to 220 and 270 nmol (109cells)-1, respectively, after 28 d with little inhibition of growth being apparent. Short-term experiments revealed that extracellular K+and Na+inhibited Cs+accumulation to a similar extent, with 90% inhibition of Cs+accumulation occurring at the highest concentrations used (50 mM-K+or Na+; 1 mM-Cs+). In all experiments, Cs+accumulation resulted in a reduction in intracellular K+, except when cells were grown in K+-depleted medium, although a stoichiometric relationship was not apparent, the amount of Cs+accumulated generally being greater than the amount of K+released. Cs+accumulation had no discernible effect on intracellular Na+. When K+, Na+, Rb+, Li+or Tl+were supplied at equimolar (1 mM) concentrations to Cs+, only Tl+significantly reduced Cs+accumulation. However, an approximately 50% inhibition of Cs+accumulation resulted when concentrations of K+, Na+, Rb+or Li+were increased to 10 mM, which suggests that Cs+may have a higher affinity for the monovalent cation transport system than K+, Rb+and TI+also caused a decrease in intracellular K+, whereas Na+and Li+stimulated K+uptake. Cs+accumulation was dependent on the external Cs+concentration and showed a linear relationship to external Cs+concentrations≤2 mM over 12 h incubation. However, prolonged incubation in external Cs+concentrations≥ 0·8 mM resulted in Cs+release from the cells and after 48 h, similar amounts of Cs+and K+were present in cells incubated at these higher concentrations. Cs+accumulation was energy- and pH-dependent. Incubation in the light at 4 °C, or in the presence of 3(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), or at 22 °C in the dark resulted in decreased Cs+accumulation and decreased K+release from the cells. Increased amounts of Cs+were accumulated as the pH of the external medium was increased, with maximal accumulation [approximately 1330 nmol Cs+(109cells)-1after 24 h incubation] occurring at pH 10, the highest pH value used. It is suggested that an important mechanism of Cs+toxicity inSynechocystisPCC 6803 arises through replacement of cellular K+by Cs+. The possible role of primary producers such as cyanobacteria in the mobilization of this radionuclide in aquatic habitats is discussed.
Homologous regions of the Salmonella enteritidis virulence plasmid and the chromosome of Salmonella typhi encode thiol: disulphide oxidoreductases belonging to the DsbA thioredoxin family
Authors: Rodríguez-Peña José M. , Alvarez Isabel , Ibáñez Magdalena , Rotger Rafael 
Published: June 2009

The nucleotide sequence relatedness between the chromosome of Salmonella typhi and the virulence plasmid of Salmonella enteritidis was investigated using short DNA probes of < 2 kb covering the whole virulence plasmid sequence. Only one homologous region was detected. This region was subsequently cloned and partially sequenced. Sequences closely related to the pefl gene and the ORFs orf7, orf8 and orf9, which are located downstream of the fimbrial pef operon of the Salmonella typhimurium virulence plasmid, were detected. Sequencing of the cloned S. typhi DNA fragment also revealed identity with genes of the fimbrial sef operon characterized in the chromosome of S. enteritidis. These nucleotide sequences mapped upstream of the S. typhi chromosomal region homologous to the S. enteritidis virulence plasmid. The general organization of the cloned S. typhi chromosomal fragment was similar to the fimbriae-encoding region of the S. typhimurium virulence plasmid. The deduced product of orf8 in the S. typhimurium virulence plasmid, as well as those of the corresponding ORFs in the homologous region of the S. typhi chromosome and in the S. enteritidis virulence plasmid (designated dlt and dlp, respectively), appeared to be related to the thioredoxin family of thiol:disulphide oxidoreductases. The dlp gene was able to complement the DTT-sensitive phenotype, the inability to metabolize glucose 1-phosphate and the low alkaline phosphatase activity of a dsbA mutant of Escherichia coli. The dlt gene partially complemented the lack of alkaline phosphatase activity, but not the other mutant phenotypes. The products of both genes could be detected using the T7 RNA polymerase promoter expression system. The estimated molecular masses of the products of the dlt and dlp genes by SDS-PAGE were 26 and 23 kDa, respectively, the first being in agreement with the deduced amino acid sequence and the latter, somewhat smaller. The processing of a possible leader peptide in the Dlp protein, but not in the Dlt protein, could be responsible for this difference. The Dlp protein appeared as a doublet band on SDS-PAGE, which is characteristic of the oxidized and reduced states of this kind of protein.
The EMBL accession numbers for the sequences of dlt and dlp reported in this paper are X94325 and X94326, respectively.
Crystalline surface protein of Peptostreptococcus anaerobius
Authors: Kotiranta Anja , Haapasalo Markus , Lounatmaa Kari , Kari Kirsti 
Published: June 2009

SUMMARY
The surface ultrastructure of three anaerobic Gram-positive cocci frequently encountered in oral infections, Peptostreptococcus micros, P. magnus and P. anaerobius, was studied. The type strains of P. micros (DSM 20468) and P. anaerobius (ATCC 27337), several clinical isolates of both species and the type strain of P. magnus (DSM 20470) were included. Thin-sectioned cells studied by electron microscopy revealed a homogeneous layer outside the peptidoglycan layer in P. anaerobius. In P. micros and P. magnus a more amorphous layer was present. No periodic structures were seen in negatively stained whole cells of these three species. However, in freeze-etched cells of P. anaerobius a crystalline surface protein layer (S-layer) was detected. No periodicity was seen in any of the P. micros strains or the magnus type strain by the methods used, but a periodic pattern was observed in negatively stained specimens of cell wall fragments of sonicated P. anaerobius cells. No capsular material was visible outside the S-layer in P. anaerobius. The cells of the Peptostreptococcus spp. were extracted for 30 min with detergents and urea. One er cent SDS and 6 M urea both extracted a major 78 kDa protein from all strains of P. anaerobius. Extraction of P. micros and P. magnus cells did not reveal any major protein bands comparable to that of P. anaerobius. Surface biotinylation of cells followed by Western blotting and detection by alkaline-phosphatase-conjugated extravidin showed strong staining of the 78 kDa band in P. anaerobius, further indicating that this molecule is located on the surface of the cell and is the S-protein. Another protein, of 127 kDa, was also detected by surface biotinylation in all P. anaerobius strains. No differences were detected in colony morphology or cell surface structures between the four strains. Isoelectric focusing of the proteins of P. anaerobius revealed that the S-proteins of individual strains have different pl values, ranging from 5.3 to 6.9.
The signal transducer encoded by ampG is essential for induction of chromosomal AmpC -lactamase in Escherichia coli by -lactam antibiotics and unspecific inducers
Authors: Schmidt Herbert , Korfmann Gisela , Barth Holger , Martin Hans H. 
Published: June 2009

SUMMARY
Chemical mutagenesis of the AmpC
-lactamase-hyperinducible Escherichia coli strain SN0301/pNu305 carrying the cloned ampC and ampR genes from Citrobacter freundii OS60 gave four independent mutants in which
-lactamase was no longer inducible, or was inducible only to a low level, by
-lactam antibiotics. The genes ampC, ampR, ampD and ampE, which were essential for
-lactamase induction, were functional in these mutants. In all four mutants, the sites of mutation were mapped to 9.9 min on the E. coli chromosome. Complementation with wild-type ampG restored inducibility of
-lactamase to wild-type levels. The nucleotide sequence of all four mutant ampG alleles (ampG1, ampG3, ampG4 and ampG5) was determined. In three of the mutants, a single base exchange led to an amino acid change from glycine to aspartate at different sites in the deduced amino acid sequence. In the fourth mutant (ampG4), with low-level inducibility, the nucleotide sequence was identical to wild-type ampG. Spontaneous back-mutation of the chromosomal ampG1 mutant resulted in restoration of wild-type inducibility and a return to the wild-type ampG sequence. Unspecific induction by components of the growth medium was also dependent on intact ampG function.
Organization of carbamoyl-phosphate synthase genes in Neisseria gonorrhoeae includes a large, variable intergenic sequence which is also present in other Neisseria species
Authors: Lawson Fiona S. , Billowes Finola M. , Dillon Jo-Anne R. 
Published: June 2009

SUMMARY
The carbamoyl-phosphate synthase (CPS) enzyme in prokaryotes is a heterodimer, encoded by genes commonly called carA and carB. In most prokaryotes examined, these genes are separated by up to 24 bp and are cotranscribed. In Pseudomonas aeruginosa, carA and carB are also co-transcribed, but are separated by 682 bp. We have determined the complete DNA sequence of the carA and carB genes of Neisseria gonorrhoeae strain CH811. carA (1125 bp) and carB (3237 bp) are similar in size and sequence to other prokaryotic CPS genes, however they are separated by an intervening sequence of 3290 bp which has no similarity to the intervening sequence between other CPS genes; furthermore, putative transcription terminators are found downstream of both carA and carB. Several neisserial repetitive sequences were identified within the 9 kb sequenced, as well as novel 120 and 150 bp repeats (designated RS6 and RS7, respectively) which were found within the intervening sequence between carA and carB. To determine whether the intervening sequence observed in N. gonorrhoeae CH811 was not unusual, the sequence between carA and carB was amplified by PCR from 30 isolates of N. gonorrhoeae. The intervening sequence was found to vary in size, from approximately 2·2 to 3·7 kb, although the carA and carB genes themselves did not vary in size in isolates with functional CPS enzyme. A similar large, variably sized intervening sequence was also found between the carA and carB genes of 12 isolates of N. meningitidis and 18 commensal Neisseria isolates comprising nine species. This unexpected organization of the CPS genes in N. gonorrhoeae is therefore widespread throughout the genus Neisseria.
The immunogenicity of recombinant Mycobacterium smegmatis bearing BCG genes
Authors: Falcone Valeria , Bassey Effiong , Jacobs William , Collins Frank 
Published: June 2009

SUMMARYSpecific pathogen-free C57BL/6 mice infected with recombinantMycobacterium smegmatis(rM. smegmatis) bearing BCG genes showed increased splenic survival compared to those receiving the vector control (plasmid DNA only). The mouse-passaged rM. smegmatis(J3R) survived in peritoneal macrophages better than the vector control, regardless of whether the macrophages were infectedin vivo or in vitro. When rM. smegmatisJ3R was cultured in synthetic Proskauer-Beck-Tween medium, protein bands characteristic of BCG culture filtrates and not present in the vector control preparation were observed. Mice immunized with two doses of heat-killed J3R suspended in Freund's adjuvant were able to limit the growth of virulentMycobacterium tuberculosiswithin the lung and spleen compared to that observed in control mice receiving adjuvanted vector control or Freund's adjuvant alone.
Cardiac air transit following venous air embolism and right ventricular air aspiration*
Authors: Schäfer S. T. , Lindemann J. , Neumann A. , Brendt P. , Kaiser G. M. , Peters J. 
Published: June 2009

SummaryUsing intra‐cardiac echocardiography in anaesthetised swine we tested the hypotheses that embolised air (i) passes immediately through the right atrium into the ventricle; (ii) persists in the right ventricle for a long time; (iii) is detectable for longer within the right ventricle or main pulmonary artery than the right atrium, and (iv) right ventricular aspiration recovers more air than right atrial aspiration. Following intravenous injection of different air volumes the air appeared in the right atrium in a mean (95% CI) of 3 s (2.5–3.5 s) and almost simultaneously in the right ventricle after 5 s (3.9–6.0 s), but air persisted for longer in the right ventricle (420 s; (367–473 s)) and pulmonary artery (541 s; (475–606 s)) than in the right atrium (404 s (353–457 s)), particularly with larger air volumes and in the semi‐upright position. More air was recovered via a right ventricular catheter than an atrial catheter (52% vs 25%, p < 0.01).