bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heart rate variability in acute psychosis
Authors: Valkonen‐Korhonen Minna , Tarvainen Mika P. , Ranta‐Aho Perttu , Karjalainen Pasi A. , Partanen Juhani , Karhu Jari , Lehtonen Johannes 
Published: August 2003

AbstractHeart rate variability (HRV) provides reliable tools to assess the integrity and reactivity of autonomic nervous function. Our aim was to examine HRV in the resting condition and during different mental loads in acute psychosis compared to healthy controls. HRV was measured in 17 first‐episode drug‐naive patients with psychosis and 21 healthy controls during oddball tasks and while performing the Wisconsin Card Sorting Test. A discrete event series was constructed by an adaptive QRS detector algorithm and power spectrum estimation was carried out. The RMSSD (representing interval differences of successive heartbeats) and the amount of high frequency (HF) power were significantly reduced in patients. Moreover, the patients' HRV remained unaltered during the tasks, whereas in controls the HRV diminished with increasing mental load of the task. Patients with psychosis displayed less short‐term HR reactivity than healthy controls. They also failed to adapt HRV according to the task‐connected strain. Acute psychosis is characterized by a limited capacity to respond to external demands at the level of autonomic nervous system.
Let's face the music: A behavioral and electrophysiological exploration of score reading
Authors: Gunter Thomas C. , Schmidt Björn‐Helmer , Besson Mireille 
Published: August 2003

AbstractThis experiment was carried out to determine whether reading diatonic violations in a musical score elicits similar endogenous ERP components when hearing such violations in the auditory modality. In the behavioral study, musicians were visually presented with 120 scores of familiar musical pieces, half of which contained a diatonic violation. The score was presented in a measure‐by‐measure manner. Self‐paced reading was significantly delayed for measures containing a violation, indicating that sight reading a violation requires additional effort. In the ERP study, the musical phrases were presented in a “RSVP”‐like manner. We predicted that diatonic violations would elicit a late positive component. However, the ERP associated with the measure where a violation was presented showed a negativity instead. The negativity started around 100 ms and lasted for the entire recording period. This long‐lasting negativity encompassed at least three distinct effects that were possibly related to violation detection, working memory processing, and a further integration/interpretation process.
Developmental differences in behavioral and event‐related brain responses associated with response preparation and inhibition in a go/nogo task
Authors: Jonkman L. M. , Lansbergen M. , Stauder J. E. A. 
Published: August 2003

AbstractThe present study investigated developmental trends in response inhibition and preparation by studying behavior and event‐related brain activity in a cued go/nogo task, administered to nine‐year‐old children and young adults. Hits, false alarms, inattention, and impulsivity scores and ERP measures of inhibition (fronto‐central nogo‐N2 and P3), target selection (parietal go‐nogo P3 difference), and response preparation (contingent negative variation; CNV) were collected. Higher false alarm and impulsivity scores and the absence of the fronto‐central nogo P3 all suggest a developmental lag in response inhibition in children. A developmental lag in sustained attention processes was suggested by worse target detection and larger parietal target/nontarget P3 effects in children. Cue orientation and response preparation processes were respectively measured by early and late CNV activity. Children displayed smaller early CNV amplitudes at fronto‐central locations, but mature late CNV. The smaller early CNV activity might indicate inefficient cue‐orientation processes caused by incomplete frontal lobe development.
Effects of artificial and natural baroreceptor stimulation on nociceptive responding and pain
Authors: Edwards Louisa , McIntyre David , Carroll Douglas , Ring Christopher , France Christopher R. , Martin Una 
Published: August 2003

AbstractThe arterial baroreflex may mediate hypertensive hypoalgesia. Carotid baroreceptors can be artificially stimulated by neck suction and inhibited by compression. Effects of brief neck suction and compression on nociceptive responding and pain were studied in 25 normotensive adults. The sural nerve was electrocutaneously stimulated at threshold intensity during systole or diastole combined with neck suction, neck compression, or no pressure. Nociceptive responding was indexed by electromyographic activity elicited in the biceps femoris. Participants rated the intensity of sural stimulation. Although artificial baroreceptor stimulation (suction) did not affect nociceptive responding, baroreceptor inhibition (compression) reduced pain ratings. In contrast, natural baroreceptor stimulation during systole reduced nociceptive responding compared to diastole, but did not affect pain ratings. The data provide partial support for baroreflex modulation of pain.
Early processing stages are modulated when auditory stimuli are presented at an attended moment in time: An event‐related potential study
Authors: LANGE Kathrin , Rösler Frank , Röder Brigitte 
Published: August 2003

AbstractThe present study investigated with event‐related potentials whether attending to a moment in time modulates the processing of auditory stimuli at a similar early, perceptual level as attending to a location in space. The participants listened to short (600 ms) and long (1,200 ms) intervals marked by white noise bursts. The task was to attend in alternating runs either to the short or to the long intervals and to respond to rare offset markers that differed in intensity from the frequent standard offset markers. Prior to the to‐be‐attended moment, a slow negative potential developed over the frontal scalp. Stimuli presented at the attended compared to the unattended moments in time elicited an enhanced N1 and an enhanced posteriorly distributed positivity (300–370 ms). The results show that attention can be flexibly controlled in time and that not only late but also early perceptual processing stages are modulated by attending to a moment in time.
Early posterior ERP components do not reflect the control of attentional shifts toward expected peripheral events
Authors: Velzen José van , Eimer Martin 
Published: August 2003

AbstractPrevious experiments investigating ERP correlates of anticipatory attention shifts triggered by central symbolic cues have identified a contralateral “early directing attention negativity,” which was assumed to be generated by processes involved in the control of spatial orienting. Here we demonstrate that this component is not directly linked to the control of attentional shifts, but instead reflects the selection of task‐relevant aspects of cue stimuli. In contrast, later ERP components triggered during covert attentional shifts are insensitive to physical cue attributes, and thus appear to be genuine electrophysiological correlates of covert attentional control mechanisms.
Research Leading to Action: A Study of Accessibility of a CAMH Service to Ethnic Minority Families
Authors: Messent Philip , Murrell Margaret 
Published: August 2003

Background: This article describes an action research project aimed at examining the accessibility of a child and adolescent mental health service to its ethnic minority populations.Method: A Child and Adolescent Mental Health Service was involved in a process of inquiry, deciding first to compare rate of referral and treatment outcomes for the four largest ethnic groups amongst the client population. Following discussion of findings throughout the service, groups of Bangladeshi service users and professionals were interviewed about low rates of referral amongst this community.Results: By highlighting the different referral rates and profiles of different ethnic groups, the study elicited an increasingly shared commitment across the service to addressing issues of accessibility to ethnic minority communities.Conclusions: The study is presented as one possible model of response to the challenge to all public services made by Macpherson (1999), to examine the ‘appropriateness’ of the service offered to different ethnic populations.
Characteristics of the Detained and Informal Child and Adolescent Psychiatric In‐Patient Populations
Authors: Mears Alex , White Richard , O'Herlihy Anne , Worrall Adrian , Banerjee Sube , Jaffa Tony , Hill Peter , Lelliott Paul 
Published: August 2003

Background: This project surveyed the use of the Children Act and the Mental Health Act in in‐patient child and adolescent mental health services in England and Wales.Methods: Data were collected as a day census from child and adolescent psychiatric inpatient units, questionnaire forms completed by consultant psychiatrists or key‐workers. Returns were received from 71 of the 80 units.Results: One hundred and twenty‐seven of the 663 patients had been admitted formally, the great majority under a section of the Mental Health Act. Compared with those admitted informally, those admitted formally were older, contained a higher proportion of males and had ‘adult‐type diagnoses’, mainly schizophrenia, mood disorders and personality disorder. The clinical and psychosocial characteristics of formal and informal patients were consistent with these differences.Conclusions: This study provides a timely and useful snapshot of the use of the Acts in this population.
Characterization of the RpoS Status of Clinical Isolates of
Salmonella enterica
Authors: Robbe-Saule Véronique , Algorta Gabriela , Rouilhac Isabelle , Norel Françoise 
Published: August 2003

ABSTRACT

The stationary-phase-inducible sigma factor, σ
S
(RpoS), is the master regulator of the general stress response in
Salmonella
and is required for virulence in mice.
rpoS
mutants can frequently be isolated from highly passaged laboratory strains of
Salmonella
. We examined the
rpoS
status of 116 human clinical isolates of
Salmonella
, including 41
Salmonella enterica
serotype Typhi strains isolated from blood, 38
S. enterica
serotype Typhimurium strains isolated from blood, and 37
Salmonella
serotype Typhimurium strains isolated from feces. We examined the abilities of these strains to produce the σ
S
protein, to express RpoS-dependent catalase activity, and to resist to oxidative stress in the stationary phase of growth. We also carried out complementation experiments with a cloned wild-type
rpoS
gene. Our results showed that 15 of the 41
Salmonella
serotype Typhi isolates were defective in RpoS. We sequenced the
rpoS
allele of 12 strains. This led to identification of small insertions, deletions, and point mutations resulting in premature stop codons or affecting regions 1 and 2 of σ
S
, showing that the
rpoS
mutations are not clonal. Thus, mutant
rpoS
alleles can be found in freshly isolated clinical strains of
Salmonella
serotype Typhi, and they may affect virulence properties. Interestingly however, no
rpoS
mutants were found among the 75
Salmonella
serotype Typhimurium isolates. Strains that differed in catalase activity and resistance to hydrogen peroxide were found, but the differences were not linked to the
rpoS
status. This suggests that
Salmonella
serotype Typhimurium
rpoS
mutants are counterselected because
rpoS
plays a role in the pathogenesis of
Salmonella
serotype Typhimurium in humans or in the transmission cycle of the disease.
Cloning of a Nitrilase Gene from the CyanobacteriumSynechocystissp. Strain PCC6803 and Heterologous Expression and Characterization of the Encoded Protein
Authors: Heinemann Ute , Engels Dirk , Bürger Sibylle , Kiziak Christoph , Mattes Ralf , Stolz Andreas 
Published: August 2003

ABSTRACTThe gene encoding a putative nitrilase was identified in the genome sequence of the photosynthetic cyanobacteriumSynechocystissp. strain PCC6803. The gene was amplified by PCR and cloned into an expression vector. The encoded protein was heterologously expressed in the native form and as a His-tagged protein inEscherichia coli, and the recombinant strains were shown to convert benzonitrile to benzoate. The active enzyme was purified to homogeneity and shown by gel filtration to consist probably of 10 subunits. The purified nitrilase converted various aromatic and aliphatic nitriles. The highest enzyme activity was observed with fumarodinitrile, but also some rather hydrophobic aromatic (e.g., naphthalenecarbonitrile), heterocyclic (e.g., indole-3-acetonitrile), or long-chain aliphatic (di-)nitriles (e.g., octanoic acid dinitrile) were converted with higher specific activities than benzonitrile. From aliphatic dinitriles with less than six carbon atoms only 1 mol of ammonia was released per mol of dinitrile, and thus presumably the corresponding cyanocarboxylic acids formed. The purified enzyme was active in the presence of a wide range of organic solvents and the turnover rates of dodecanoic acid nitrile and naphthalenecarbonitrile were increased in the presence of water-soluble and water-immiscible organic solvents.
Microbial and Physiological Characterization of Weakly Amylolytic but Fast-Growing Lactic Acid Bacteria: a Functional Role in Supporting Microbial Diversity in Pozol, a Mexican Fermented Maize Beverage
Authors: Díaz-Ruiz G. , Guyot J. P. , Ruiz-Teran F. , Morlon-Guyot J. , Wacher C. 
Published: August 2003

ABSTRACT

Pozol is an acid beverage obtained from the natural fermentation of nixtamal (heat- and alkali-treated maize) dough. The concentration of mono- and disaccharides from maize is reduced during nixtamalization, so that starch is the main carbohydrate available for lactic acid fermentation. In order to provide some basis to understand the role of amylolytic lactic acid bacteria (ALAB) in this fermented food, their diversity and physiological characteristics were determined. Forty amylolytic strains were characterized by phenotypic and molecular taxonomic methods. Four different biotypes were distinguished via ribotyping;
Streptococcus bovis
strains were found to be predominant.
Streptococcus macedonicus
,
Lactococcus lactis
, and
Enterococcus sulfureus
strains were also identified.
S. bovis
strain 25124 showed extremely low amylase yield relative to biomass (139 U g [cell dry weight]
−1
) and specific rate of amylase production (130.7 U g [cell dry weight]
−1
h
−1
). In contrast, it showed a high specific growth rate (0.94 h
−1
) and an efficient energy conversion yield to bacterial cell biomass (0.31 g of biomass g of substrate
−1
). These would confer on the strain a competitive advantage and are the possible reasons for its dominance. Transient accumulation of maltooligosaccharides during fermentation could presumably serve as energy sources for nonamylolytic species in pozol fermentation. This would explain the observed diversity and the dominance of nonamylolytic lactic acid bacteria at the end of fermentation. These results are the first step to understanding the importance of ALAB during pozol fermentation.
Comparing the Dehalogenase Gene Pool in Cultivated α-Halocarboxylic Acid-Degrading Bacteria with the Environmental Metagene Pool
Authors: Marchesi Julian R. , Weightman Andrew J. 
Published: August 2003

ABSTRACT

Culture-dependent and culture-independent approaches were used to determine the relationship between the dehalogenase gene pool in bacteria enriched and isolated on 2,2-dichloropropionic acid (22DCPA) and the environmental metagene pool (the collective gene pool of both the culturable and uncultured microbes) from which they were isolated. The dehalogenases in the pure-cultures isolates, which were able to degrade 22DCPA, were similar to previously described group I and II dehalogenases. Significantly, the majority of the dehalogenases isolated from activated sludge by degenerate PCR with primers specific for α-halocarboxylic acid dehalogenases were not closely related to the dehalogenases in any isolate. Furthermore, the dehalogenases found in the pure cultures predominated in the enrichments but were a minor component of the community used to inoculate the batch cultures. Phylogenetic analysis of the dehalogenase sequences isolated by degenerate PCR showed that the diversity of the group II
deh
gene was greater than that of the group I
deh
gene. Direct plating of the activated sludge onto minimal media supplemented with 22DCPA resulted in biomass and DNA from which dehalogenases were amplified. Analysis of the sequences revealed that they were much more closely related to the sequences found in the community used to start the enrichments. However, no pure cultures were obtained with this isolation method, and thus no pure cultures were available for identification. In this study we examined the link between genes found in pure cultures with the metagene pool from which they were isolated. The results show that there is a large bias introduced by culturing, not just in the bacteria isolated but also the degradative genes that they contain. Moreover, our findings serve as a caveat for studies involving the culturing of pure cultures of bacteria and conclusions which are drawn from analysis of these organisms.
Overexpression of the Gene Encoding GTP:Mannose-1-Phosphate Guanyltransferase,
mpg1
, Increases Cellular GDP-Mannose Levels and Protein Mannosylation in
Trichoderma reesei
Authors: Zakrzewska Anna , Palamarczyk Grazyna , Krotkiewski Hubert , Zdebska Ewa , Saloheimo Markku , Penttilä Merja , Kruszewska Joanna S. 
Published: August 2003

ABSTRACT

To elucidate the regulation and limiting factors in the glycosylation of secreted proteins, the
mpg1
and
dpm1
genes from
Trichoderma reesei
(
Hypocrea jecorina
) encoding GTP:α
-d-
mannose-1-phosphate guanyltransferase and dolichyl phosphate mannose synthase (DPMS), respectively, were overexpressed in
T. reesei
. No significant increases were observed in DPMS activity or protein secretion in
dpm1
-overexpressing transformants, whereas overexpression of
mpg1
led to a twofold increase in GDP-mannose (GDPMan) levels. GDPMan was effectively utilized by mannnosyltransferases and resulted in hypermannosylation of secreted proteins in both N and O glycosylation. Overexpression of the
mpg1
gene also increased the transcription of the
dpm1
gene and DPMS activity. Our data indicate that the level of cellular GDPMan can play a major regulatory role in protein glycosylation in
T. reesei
.
Vibrio harveyi
Nitroreductase Is Also a Chromate Reductase
Authors: Kwak Young Hak , Lee Dong Seok , Kim Han Bok 
Published: August 2003

ABSTRACT

The chromate reductase purified from
Pseudomonas ambigua
was found to be homologous with several nitroreductases.
Escherichia coli
DH5α and
Vibrio harveyi
KCTC 2720 nitroreductases were chosen for the present study, and their chromate-reducing activities were determined. A fusion between glutathione
S
-transferase (GST) and
E. coli
DH5α NfsA (GST-EcNfsA), a fusion between GST and
E. coli
DH5α NfsB (GST-EcNfsB), and a fusion between GST and
V. harveyi
KCTC 2720 NfsA (GST-VhNfsA) were prepared for their overproduction and easy purification. GST-EcNfsA, GST-EcNFsB, and GST-VhNFsA efficiently reduced nitrofurazone and 2,4,6-trinitrotoluene (TNT) as their nitro substrates. The

K
m

values for GST-EcNfsA, GST-EcNfsB, and GST-VhNfsA for chromate reduction were 11.8, 23.5, and 5.4 μM, respectively. The
V
max
values for GST-EcNfsA, GST-EcNfsB, and GST-VhNfsA were 3.8, 3.9, and 10.7 nmol/min/mg of protein, respectively. GST-VhNfsA was the most effective of the three chromate reductases, as determined by each
V
max
/

K
m

value. The optimal temperatures of GST-EcNfsA, GST-EcNfsB, and GST-VhNfsA for chromate reduction were 55, 30, and 30°C, respectively. Thus, it is confirmed that nitroreductase can also act as a chromate reductase. Nitroreductases may be used in chromate remediation. GST-EcNfsA, GST-EcNfsB, and GST-VhNfsA have a molecular mass of 50 kDa and exist as a monomer in solution. Thin-layer chromatography showed that GST-EcNfsA, GST-EcNfsB, and GST-VhNfsA contain FMN as a cofactor. GST-VhNfsA reduced Cr(VI) to Cr(III). Cr(III) was much less toxic to
E. coli
than Cr(VI).
Rhizobium leguminosarum
Biovar viciae 1-Aminocyclopropane-1-Carboxylate Deaminase Promotes Nodulation of Pea Plants
Authors: Ma Wenbo , Guinel Frèdèrique C. , Glick Bernard R. 
Published: August 2003

ABSTRACT

Ethylene inhibits nodulation in various legumes. In order to investigate strategies employed by
Rhizobium
to regulate nodulation, the 1-aminocyclopropane-1-carboxylate (ACC) deaminase gene was isolated and characterized from one of the ACC deaminase-producing rhizobia,
Rhizobium leguminosarum
bv. viciae 128C53K. ACC deaminase degrades ACC, the immediate precursor of ethylene in higher plants. Through the action of this enzyme, ACC deaminase-containing bacteria can reduce ethylene biosynthesis in plants. Insertion mutants with mutations in the rhizobial ACC deaminase gene (
acdS
) and its regulatory gene, a leucine-responsive regulatory protein-like gene (
lrpL
), were constructed and tested to determine their abilities to nodulate
Pisum sativum
L. cv. Sparkle (pea). Both mutants, neither of which synthesized ACC deaminase, showed decreased nodulation efficiency compared to that of the parental strain. Our results suggest that ACC deaminase in
R. leguminosarum
bv. viciae 128C53K enhances the nodulation of
P. sativum
L. cv. Sparkle, likely by modulating ethylene levels in the plant roots during the early stages of nodule development. ACC deaminase might be the second described strategy utilized by
Rhizobium
to promote nodulation by adjusting ethylene levels in legumes.
Elucidation of the Transmission Patterns of an Insect-Borne Bacterium
Authors: Darby A. C. , Douglas A. E. 
Published: August 2003

ABSTRACTQuantitative data on modes of transmission are a crucial element in understanding the ecology of microorganisms associated with animals. We investigated the transmission patterns of a γ-proteobacterium informally known as pea aphidBemisia-like symbiont (PABS), also known as T-type, which is widely but not universally distributed in natural populations of the pea aphid,Acyrthosiphon pisum. The vertical transmission of PABS to asexual and sexual morphs and sexually produced eggs was demonstrated by a diagnostic PCR-based assay, and the maximum estimated failure rate was 2%. Aphids naturally lacking PABS acquired PABS bacteria administered via the diet, and the infection persisted by vertical transmission for at least three aphid generations. PABS was also detected in two of five aphid honeydew samples tested and in all five siphuncular fluid samples tested but in none of 15 samples of salivary secretions from PABS-positive aphids. However, PABS-negative aphids did not acquire PABS when they were cocultured with PABS-positive aphids; the maximal estimated level of horizontal transmission was 18%. A deterministic model indicated that the force of infection by a horizontal transmission rate of 3% is sufficient to maintain a previously described estimate of the prevalence of PABS-positive aphids (37%), if the vertical transmission rate is 98%. We concluded that PABS infections inA. pisumcan be maintained by high vertical transmission rates and occasional horizontal transmission, possibly via the oral route, in the absence of selection either for or against aphids bearing this bacterium.