bluuebunny/crossref_metadata_2025_split huggingface dataset:
OBC signal fidelity
Authors: Norris Michael W. , Johnson Marvin L. , Walsh Mat 
Published: November 2006

ABSTRACTA suite of three tests was performed to characterize the signal fidelity of OBC 4C acquisition systems. The test methodology was to evaluate individual sensor stations by acquiring source lines that were parallel to the in‐line and cross‐line horizontal sensors and source lines that were at 45° to the in‐line and cross‐line sensors. This technique provides constant azimuth gathers with a uniform offset range and removes issues associated with source array directivity.Characterization of the test data identified the frequency content of the geophone signals and the correlation between the vertical and cross‐line geophones as the most sensitive indicators of signal infidelity. In the former case, stations with questionable signal fidelity exhibited a very reverberatory signal. This signal was most evident on the cross‐line sensor. In the latter case, when normalized cross‐correlation coefficients are computed in a moving window, the cross‐line sensor and the vertical sensor are highly correlated, beginning several hundred milliseconds after the first arrivals.These characteristics can be exploited to allow stations with questionable signal fidelity to be programmatically identified. One means of identifying questionable stations is to compute the histogram of the instantaneous frequency. The frequency distributions from questionable stations are unambiguously distinguishable from stations that exhibit better signal fidelity. It was noted that signal fidelity appeared as a range, between acceptable and poor. To characterize the signal fidelity of an acquisition system adequately, the number of test samples must be statistically significant.
High levels of variation despite genetic fragmentation in populations of the endangered mountain pygmy‐possum,Burramys parvus, in alpine Australia
Authors: MITROVSKI P. , HEINZE D. A. , BROOME L. , HOFFMANN A. A. , WEEKS A. R. 
Published: November 2006

AbstractIn endangered mammals, levels of genetic variation are often low and this is accompanied by genetic divergence among populations. The mountain pygmy‐possum (Burramys parvus) is an endangered marsupial restricted to the alpine region of Victoria and New South Wales, Australia. By scoring variation at eight microsatellite loci, we found thatB. parvuspopulations exhibit high levels of genetic divergence and fall into three distinct groups from the northern, central and southern areas of the distribution of this species, consistent with previous assessments of mitochondrial DNA variation.FSTvalues between populations from these regions ranged from 0.19 to 0.54. Within the central area, there was further genetic fragmentation, and a linear association between genetic and geographical distance. This pattern is likely to reflect limited dispersal across barriers despite the fact that individualB. parvuscan move several kilometres. Levels of genetic variation within populations were high with the exception of a southern population where there was evidence of inbreeding. From a conservation perspective, all three areas whereB. parvusare found should be considered as separate gene pools; management of populations within these areas needs to take into account the low gene flow between populations, as well as threats posed by roads, resorts and other developments in the alpine region. The low genetic variability and inbreeding in the southern population is of particular concern given the high levels of variability in otherB. parvuspopulations.
MvfR, a key Pseudomonas aeruginosa pathogenicity LTTR‐class regulatory protein, has dual ligands
Authors: Xiao Gaoping , Déziel Eric , He Jianxin , Lépine François , Lesic Biliana , Castonguay Marie‐Hélène , Milot Sylvain , Tampakaki Anastasia P. , Stachel Scott E. , Rahme Laurence G. 
Published: November 2006

SummaryMvfR (PqsR), a Pseudomonas aeruginosa LysR‐type transcriptional regulator, plays a critical role in the virulence of this pathogen. MvfR modulates the expression of multiple quorum sensing (QS)‐regulated virulence factors; and the expression of the phnAB and pqsA‐E genes that encode functions mediating 4‐hydroxy‐2‐alkylquinolines (HAQs) signalling compounds biosynthesis, including 3,4‐dihydroxy‐2‐heptylquinoline (PQS) and its precursor 4‐hydroxy‐2‐heptylquinoline (HHQ). PQS enhances the in vitro DNA‐binding affinity of MvfR to the pqsA‐E promoter, to suggest it might function as the in vivo MvfR ligand. Here we identify a novel MvfR ligand, as we show that HHQ binds to the MvfR ligand‐binding‐domain and potentiates MvfR binding to the pqsA‐E promoter leading to transcriptional activation of pqsA‐E genes. We show that HHQ is highly produced in vivo, where it is not fully converted into PQS, and demonstrate that it is required for MvfR‐dependent gene expression and pathogenicity; PQS is fully dispensable, as pqsH– mutant cells, which produce HHQ but completely lack PQS, display normal MvfR‐dependent gene expression and virulence. Conversely, PQS is required for full production of pyocyanin. These results uncover a novel biological role for HHQ; and provide novel insights on MvfR activation that may aid in the development of therapies that prevent or treat P. aeruginosa infections in humans.
Identification of an essential gene responsible for d‐Asp incorporation in the Lactococcus lactis peptidoglycan crossbridge
Authors: Veiga Patrick , Piquet Sandra , Maisons Aurélie , Furlan Sylviane , Courtin Pascal , Chapot‐Chartier Marie‐Pierre , Kulakauskas Saulius 
Published: November 2006

SummaryBacteria such as Lactococcus lactis have d‐aspartate (d‐Asp) or its amidated derivative d‐asparagine (d‐Asn), in their peptidoglycan (PG) interpeptide crossbridge. We performed a subtractive genome analysis to identify L. lactis gene yxbA, orthologues of which being present only in bacteria containing d‐amino acids in their PG crossbridge, but absent from those that instead insert l‐amino acids or glycine. Inactivation of yxbA required a complementing Streptococcus pneumoniae murMN genes, which express enzymes that incorporate l‐Ser‐l‐Ala or l‐Ala‐l‐Ala in the PG crossbridge. Our results show that (i) yxbA encodes d‐Asp ligase responsible for incorporation of d‐Asp in the PG crossbridge, and we therefore renamed it as aslA, (ii) it is an essential gene, which makes its product a potential target for specific antimicrobials, (iii) the absence of d‐Asp may be complemented by l‐Ser‐l‐Ala or l‐Ala‐l‐Ala in the L. lactis PG, indicating that the PG synthesis machinery is not selective for the side‐chain residues, and (iv) lactococcal strains having l‐amino acids in their PG crossbridge display defects in cell wall integrity, but are able to efficiently anchor cell wall proteins, indicating relative flexibility of lactococcal transpeptidation reactions with respect to changes in PG side‐chain composition.
Anisohydric but isohydrodynamic: seasonally constant plant water potential gradient explained by a stomatal control mechanism incorporating variable plant hydraulic conductance
Authors: FRANKS PETER J. , DRAKE PAUL L. , FROEND RAY H. 
Published: November 2006

ABSTRACTIsohydric and anisohydric regulations of plant water status have been observed over several decades of field, glasshouse and laboratory studies, yet the functional significance and mechanism of both remain obscure. We studied the seasonal trends in plant water status and hydraulic properties in a natural stand of Eucalyptus gomphocephala through cycles of varying environmental moisture (rainfall, groundwater depth, evaporative demand) in order to test for isohydry and to provide physiological information for the mechanistic interpretation of seasonal trends in plant water status. Over a 16 month period of monitoring, spanning two summers, midday leaf water potential (Ψleaf) correlated with predawn Ψleaf, which was correlated with water table depth below ground level, which in turn was correlated with total monthly rainfall. Eucalyptus gomphocephala was therefore not seasonally isohydric. Despite strong stomatal down‐regulation of transpiration rate in response to increasing evaporative demand, this was insufficient to prevent midday Ψleaf from falling to levels below −2 MPa in the driest month, well into the region likely to induce xylem air embolisms, based on xylem vulnerability curves obtained in the study. However, even though midday Ψleaf varied by over 1.2 MPa across seasons, the hydrodynamic (transpiration‐induced) water potential gradient from roots to shoots (ΔΨplant), measured as the difference between predawn and midday Ψleaf, was relatively constant across seasons, averaging 0.67 MPa. This unusual pattern of hydraulic regulation, referred to here as isohydrodynamic, is explained by a hydromechanical stomatal control model where plant hydraulic conductance is dependent on transpiration rate.
Decreased Expression of VEGF‐A in Rat Experimental Autoimmune Encephalomyelitis and in Cerebrospinal Fluid Mononuclear Cells from Patients with Multiple Sclerosis
Authors: Tham E. , Gielen A. W. , Khademi M. , Martin C. , Piehl F. 
Published: November 2006

AbstractVascular endothelial growth factor A (VEGF‐A) stimulates angiogenesis, but is also pro‐inflammatory and plays an important role in the development of neurological disease, where it can have both attenuating and exacerbating effects. VEGF‐B, a related molecule, is highly expressed in the central nervous system and seems to be important in neurological injury. A few studies have indicated that VEGF‐A may play a role in the pathogenesis of multiple sclerosis (MS), but the role of VEGF‐B has not been studied. We have studied the expression of VEGF‐A, ‐B and their receptors by mRNA in situ hybridization, immunohistochemistry and real‐time PCR in spinal cord from LEW rats with experimental autoimmune encephalomyelitis (EAE) and in cerebrospinal fluid (CSF) and blood samples from MS patients. Whereas VEGF‐A is downregulated in glia in EAE, the infiltrating inflammatory cells are positive for VEGF‐A. Expression of VEGF‐B and the VEGF receptors is unaltered. In addition, the levels of VEGF‐A mRNA in monocytes in CSF are lower in MS patients compared with controls. These results demonstrate a complex regulation of VEGF‐A during neuroinflammation and suggest that VEGF‐B is not involved in the pathogenesis of MS.
Impact of thrombocytosis and C‐reactive protein elevation on the prognosis for patients with renal cell carcinoma
Authors: ITO KEIICHI , ASANO TOMOHIKO , YOSHII HIDEHIKO , SATOH AKINORI , SUMITOMO MAKOTO , HAYAKAWA MASAMICHI 
Published: November 2006

Aim: C‐reactive protein (CRP) elevation is reportedly a prognostic factor in patients with renal cell carcinoma (RCC). Thrombocytosis has recently been reported also to be a prognostic factor in RCC and, like CRP, to be related to inflammatory cytokines such as interleukin‐6. The aim of this study was to evaluate the importance of both thrombocytosis and CRP elevation in tumor recurrence and prognosis for patients with RCC.Methods: The clinical records of 178 patients who underwent radical nephrectomy were reviewed. Thrombocytosis was defined as a platelet count ≥350 000/mm3, and CRP elevation was defined as a CRP level ≥1.0 mg/dL. Disease‐free survival and cause‐specific survival rates were calculated. Independent predictors for recurrence and prognosis were determined.Results: Patients with thrombocytosis and patients with elevated CRP levels had significantly higher pathological T stage, clinical stage, tumor size, histological grade, and percentage of microvascular invasion than did patients without THC and patients with CRP levels <1.0 mg/dL, respectively. There was a significant correlation between platelet counts and CRP levels. Multivariate analysis showed that distant metastasis, tumor size, grade 3 components, and CRP elevation were independent predictors for prognosis but thrombocytosis was not. In N0M0 RCC patients, tumor size, microvascular invasion, and CRP elevation were independent predictors for recurrence. CRP elevation and tumor size were independent predictors for prognosis.Conclusions: Platelet count and CRP level are strongly correlated in patients with RCC, but only CRP elevation is an independent predictor for recurrence and prognosis.
Laparoscopic versus open orchiopexy in the management of abdominal testis: A descriptive study
Authors: ABOLYOSR AHMAD 
Published: November 2006

Aims: Treatment of patients with abdominal non‐palpable testis (NPT) is still controversial among pediatric urologists. This is a prospective randomized comparative study between open and laparoscopic orchiopexy for management of abdominal testis. The aim of this study was to evaluate the success rate and morbidity of both approaches.Methods: Eighty‐two patients with a mean age of 5.3 years were evaluated by laparoscopy for 87 NPT. Patients with viable abdominal testes were randomly treated with either open or laparoscopic orchiopexy procedures.Results: On laparoscopy, 75 viable abdominal testes were found. According to location: 41 (47.1%) testes were high abdominal, 27 (31%) testes were low abdominal and 7 (8%) testes were peeping from the internal ring. Laparoscopic first stage Fowler–Stephens orchiopexy was done initially for those with high abdominal testes. For further management, all patients were divided randomly into open (36 cases) and laparoscopic (39 cases) groups where primary (with spermatic vessel preservation) or second stage Fowler‐Stephens orchiopexy was done. Statistical analysis was done using Student’s t‐test. Laparoscopic procedures showed significant less morbidity than the open counterparts. Follow up ranged from 9 to 31 months and included evaluation of testicular site and size. All testes were located satisfactorily inside the scrotum. Five cases of testicular atrophy were encountered (three and two testes with open and laparoscopic second stage Fowler‐Stephens orchiopexy respectively) after 1 year follow up.Conclusion: Results of open versus laparoscopic orchiopexy procedures (primary or staged) are fairly comparable. However, laparoscopy provides significantly less morbidity.
Dorsal onlay augmentation urethroplasty with small intestinal submucosa: Modified Barbagli technique for strictures of the bulbar urethra
Authors: DONKOV IVO I , BASHIR AZMAT , ELENKOV CHAVDAR HG , PANCHEV PETAR K 
Published: November 2006

Aim: To present the results from one clinic’s experience of using small intestinal submucosa (SIS) in augmentation urethroplasty for management of strictures of the bulbar urethra.Methods: Urethral surgery was performed in nine men with strictures 4–6 cm. All of the patients were evaluated by history, physical examination, retrograde urethrogram, and uroflowmetry. Four layers of SIS were soaked in saline or Ringer’s solution for 15 minutes at 37°C, and the inner surface of the patch was gently fenestrated with a thin scalpel. The patch was spread‐fixed onto the tunica albuginea. The mucosa was sutured to the submucosal graft first at 2–3 mm inwards from the SIS margins, then the spongiosum tissue was attached to the margins with interrupted absorbable sutures.Results: Of the nine patients who underwent augmentation urethroplasty using SIS, only one had re‐stricture at 6 months due to urethral infection. At 18 months after the surgery the uroflowmetry of the other eight patients was 20–21 mL/s. In terms of complications, six patients reported having post‐micturition dribbling, and seven patients reported lack of morning erections for 35–69 days after surgery.Conclusions: Using SIS is a safe procedure; however, long‐term follow‐up is needed to substantiate the good short‐term results.
Failure to detect urethral Trichomonas vaginalis in Japanese men with or without urethritis
Authors: MAEDA SHIN‐ICHI , KUBOTA YASUAKI , SENDA YURI , TAMAKI MASAYOSHI , YASUDA MITSURU , DEGUCHI TAKASHI 
Published: November 2006

Aim: Trichomonas vaginalis may cause symptomatic or asymptomatic urethritis in men. There are few recent studies on the prevalence of T. vaginalis infection in Japanese men, and quantification of the number of cases of urethritis attributable to this pathogen has not been performed in Japan. The aim of this study was to determine the prevalence and morbidity of T. vaginalis infection in Japanese men.Methods: One hundred subjects with or without urethritis were examined for the presence of urethral T. vaginalis using culture swabs.Results: Urethral swabs from all subjects were negative for T. vaginalis.Conclusion: These results indicate Japanese men, including those with urethritis, have a low incidence of urethral T. vaginalis infection or colonization. T. vaginalis appears to be an uncommon pathogen for male urethritis in Japan.
Elevation of serum and urinary carbohydrate antigen 19‐9 in benign hydronephrosis
Authors: AYBEK HULYA , AYBEK ZAFER , SINIK ZAFER , DEMIR SULEYMAN , SANCAK BURAK , TUNCAY LEVENT 
Published: November 2006

Objective: The aim of this study was to find out the predictive role of serum and urinary carbohydrate antigen 19‐9 levels in benign hydronephrosis and whether these levels are helpful for differentiation of complete or partial urinary obstruction.Materials and methods: Fifty‐four patients with, and 23 without, benign hydronephrosis were enrolled in this study. Serum and urinary carbohydrate antigen 19‐9 were determined by the chemiluminescence enzyme immunometric assay method and these levels were correlated with clinical factors.Results: The mean serum (P < 0.0001) and urinary (P < 0.0001) carbohydrate antigen 19‐9 and serum creatinine (P < 0.008) levels were significantly higher in the hydronephrosis group than the control group. There was significant correlation between serum and urinary carbohydrate antigen 19‐9 levels in the hydronephrosis group (r = 0.639, P < 0.0001). In the hydronephrosis group, there were no significant differences between the serum creatinine, serum or urinary carbohydrate antigen 19‐9 levels and the clinical features except symptom duration. The best cut‐off value for the serum and urinary carbohydrate antigen 19‐9 were found to be 4.84 U/mL and 29.35 U/mL, respectively.Conclusion: Serum and urinary carbohydrate antigen 19‐9 levels correlated with each other, were significantly elevated in patients with hydronephrosis and did not predict complete urinary obstruction. Benign hydronephrosis should be considered in the differential diagnosis of carbohydrate antigen 19‐9 increments, as this is what is of most importance in clinical practice.
Microbial community associated with the colonial ascidian Cystodytes dellechiajei
Authors: Martínez‐García Manuel , Díaz‐Valdés Marta , Wanner Gerhard , Ramos‐Esplá Alfonso , Antón Josefa 
Published: November 2006

SummaryThe ascidian Cystodytes dellechiajei (Della Valle, 1877) (phylum Chordata, class Ascidiacea, family Polycitoridae) is a colonial tunicate that inhabits benthic rock environments in the Atlantic, Pacific and Indian Oceans, as well as the Mediterranean Sea. Its life cycle has two phases, the adult sessile colony and the free‐living larva. Both adult zooids and larvae are surrounded by a protective tunic that contains several eukaryotic cell lines, is composed mainly of acidic mucopolysacharides associated with collagen and elastin‐like proteins, and is covered by a thin cuticle. The microbiota associated with the tunic tissues of adult colonies and larva of C. dellechiajei has been examined by optical, confocal and electron microscopy and by fluorescence in situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE), and 16S rRNA gene clone library analysis. Microscopy analyses indicated the presence inside the tunic, both for the adult and the larva, of a dense community of Bacteria while only the external surface of colony cuticle was colonized by diatoms, rodophyte algae and prokaryotic‐like epiphytes. Transmission electron microscopy showed tunic eukaryotic cells that were engulfing and lysing bacteria. 16S rRNA gene analyses (DGGE and clone libraries) and FISH indicated that the community inside the tunic tissues of the adults and larvae was dominated by Alphaproteobacteria. Bacteria belonging to the phyla Gammaproteobacteria and Bacteroidetes were also detected in the adults. Many of the 16S rRNA gene sequences in the tunic tissues were related to known aerobic anoxygenic phototrophs (AAP), like Roseobacter sp. and Erythrobacter sp. In order to check whether the gene pufM, coding for the M subunit of the reaction centre complex of aerobic anoxygenic photosynthesis, was being expressed inside the ascidian tissues, two libraries, one for an adult colony and one for larva, of cDNA from the expressed pufM gene were also constructed. The sequences most frequently (64% for colony and 67% for larva) retrieved from these libraries presented > 90% aa identity with the pufM gene product of the Roseobacter‐like group, a cluster of AAP widely detected in marine planktonic environments.
Plant biological warfare: thorns inject pathogenic bacteria into herbivores
Authors: Halpern Malka , Raats Dina , Lev‐Yadun Simcha 
Published: November 2006

SummaryThorns, spines and prickles are among the rich arsenal of antiherbivore defence mechanisms that plants have evolved. Many of these thorns are aposematic, that is, marked by various types of warning coloration. This coloration was recently proposed to deter large herbivores. Yet, the mechanical defence provided by thorns against large herbivores might be only the tip of the iceberg in a much more complicated story. Here we present evidence that thorns harbour an array of pathogenic bacteria that are much more dangerous to herbivores than the painful mechanical wounding by the thorns. Pathogenic bacteria like Clostridium perfringens, the causative agent of the life‐threatening gas gangrene, and others, were isolated and identified from date palm (with green‐yellow‐black aposematic spines) and common hawthorn (with red aposematic thorns). These thorn‐inhabiting bacteria have a considerable potential role in antiherbivory, and may have uniquely contributed to the common evolution of aposematism (warning coloration) in thorny plants.
Do Informed Traders Win? An Analysis of Changes in Corporate Ownership around Substantial Shareholder Notices*
Authors: DA SILVA ROSA RAYMOND , SAVERIMUTTU NIRMAL , WALTER TERRY 
Published: November 2006

ABSTRACTThe financial economics literature typically distinguishes between two classes of investors, namely ‘informed’ and ‘uninformed’ traders. Informed traders are those who possess some fundamental information about the true value of an asset, which is not readily available to other traders. Presuming that this information advantage is obtained from costly information search there is a general assumption that these traders realize superior returns. Unlike previous researchers, we access a unique panel of institutional and retail ownership (Clearing House Electronic Subregister System, CHESS records) that enable us to develop powerful measures that capture and benchmark abnormal changes in the share register across a number of dimensions. We find some evidence of a positive and significant relationship between the level of informed trading in the share register and abnormal market performance. However, our results suggest that informed traders move in and out of the share register in response to abnormal market performance, rather than in anticipation of abnormal market performance.