bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute tryptophan depletion in schizophrenia
Authors: GOLIGHTLY K. L. , LLOYD J. A. , HOBSON J. E. , GALLAGHER P. , MERCER G. , YOUNG A. H. 
Published: July 2002

Background. Brain 5-hydroxytryptamine (5-HT) function is implicated in the pathophysiology of
schizophrenia and the action of new generation antipsychotic drugs. By the method of acute
tryptophan depletion (ATD) 5-HT can be selectively manipulated. The aim of this study was to
examine the effects of ATD on symptoms, mood and cognition in schizophrenic patients.Methods. Twenty-eight schizophrenic patients participated in a within subject, double-blind,
placebo-controlled counterbalanced cross-over study. Patients with a concurrent DSM-IV axis I
diagnosis were excluded. Symptoms, mood and cognitive function were evaluated following ATD
or ingestion of a control drink.Results. The depleting drink significantly reduced plasma total and free tryptophan. Tryptophan/LNAA
ratios did not alter with the administration of the control drink, but differed significantly
with ATD; however there was no significant change in tyrosine/LNAA ratio. ATD led to
impairment in executive function that was dependent upon the order of administration. Tests of
sustained attention, speed of processing, and everyday memory were not affected. No effects were
observed on subjective mood ratings, movement disorders or PANSS scores.Conclusions. Acute tryptophan depletion selectively alters cognition in schizophrenia, but has no
effect on symptoms, mood ratings or movement disorders.
Criminality and antisocial behaviour in unselected
men with sex chromosome abnormalities
Authors: GÖTZ M. J. , JOHNSTONE E. C. , RATCLIFFE S. G. 
Published: July 2002

Background. Previous studies on male patients with sex chromosome abnormalities (SCA), namely
XYY and XXY, suggest that such patients commit criminal acts more frequently than expected.
Most of these studies are affected by ascertainment bias.Methods. Using a population-based sample of men with SCA, identified by screening 34380 infants
at birth between 1967 and 1979, comparison between 16 XYY men, 13 XXY men and 45 controls
were made in terms of frequency of antisocial personality disorder (APD) using the Schedule for
Affective Disorders and Schizophrenia lifetime version. Rates of criminal convictions were
examined in 17 XYY men, 17 XXY men and 60 controls.Results. XYY males showed a significantly higher frequency of antisocial behaviour in adolescence
and adulthood and of criminal convictions than the controls, but multiple regression analysis
showed this to be mediated mainly through lowered intelligence. Property offences constituted the
majority of offences in all groups. The XXY men did not show an increased rate of criminal
convictions. It is possible that this apparently negative result relates to the relatively small numbers
of cases and hence low power of this study.Conclusions. The findings of this study carry the advantage of not being affected by ascertainment
bias and the disadvantage of having low power. It provides evidence for a slightly increased liability
to antisocial behaviour in XYY men.
Impairment of olfactory identification in
obsessive–compulsive disorder
Authors: BARNETT R. , MARUFF P. , PURCELL R. , WAINWRIGHT K. , KYRIOS M. , BREWER W. , PANTELIS C. 
Published: July 2002

Background. Olfactory identification ability has been associated with processing in the orbitofrontal
cortex (OFC), an area that has been implicated in the pathophysiology of obsessive–compulsive
disorder (OCD). Although olfactory sensitivity is normal in patients with OCD, no study has
investigated olfactory identification in this disorder.Methods. A group of 20 subjects with OCD and 23 age- and education-matched controls performed
a standardized test of olfactory identification. They also performed computerized tests of spatial
memory span, spatial working memory and spatial recognition memory that have been shown
previously to be sensitive to cognitive deficits in patients with OCD.Results. Performance on the olfactory identification task, spatial recognition task and spatial span
task was significantly worse in the OCD group than controls.Conclusions. While impairment in spatial cognition is consistent with previous studies of OCD, its
significance for brain-behaviour models of OCD is unclear. However, the finding of abnormal
olfactory identification in patients with OCD is consistent with the hypothesis that there is a
disruption to processing at the level of the OFC in the disorder.
Genetic differences in alcohol sensitivity and the
inheritance of alcoholism risk
Authors: HEATH A. C. , MADDEN P. A. F. , BUCHOLZ K. K. , DINWIDDIE S. H. , SLUTSKE W. S. , BIERUT L. J. , ROHRBAUGH J. W. , STATHAM D. J. , DUNNE M. P. , WHITFIELD J. B. , MARTIN N. G. 
Published: July 2002

Background. Substantial evidence exists for an important genetic contribution to alcohol dependence
risk in women and men. It has been suggested that genetically determined differences in alcohol
sensitivity may represent one pathway by which an increase in alcohol dependence risk occurs.Methods. Telephone interview follow-up data were obtained on twins from male, female and unlike-sex twin pairs who had participated in an alcohol challenge study in 1979–81, as well as other pairs
from the same Australian twin panel surveyed by mail in 1980–82.Results. At follow-up, alcohol challenge men did not differ from other male twins from the same
age cohort on measures of lifetime psychopathology or drinking habits; but alcohol challenge
women were on average heavier drinkers than other women. Acomposite alcohol sensitivity measure,
combining subjective intoxication and increase in body-sway after alcohol challenge in 1979–81,
exhibited high heritability (60%). Parental alcoholism history was weakly associated with decreased
alcohol sensitivity in women, but not after adjustment for baseline drinking history, or in men. High
alcohol sensitivity in men was associated with substantially reduced alcohol dependence risk
(OR=0·05, 95% CI 0·01–0·39). Furthermore, significantly decreased (i.e. low) alcohol sensitivity
was observed in non-alcoholic males whose MZ co-twin had a history of alcohol dependence,
compared to other non-alcoholics. These associations remained significant in conservative analyses
that controlled for respondents' alcohol consumption levels and alcohol problems in 1979–81.Conclusions. Men (but not women) at increased genetic risk of alcohol dependence (assessed by MZ
co-twin's history of alcohol dependence) exhibited reduced alcohol sensitivity. Associations with
parental alcoholism were inconsistent.
Diversity and evolution of macrohabitat use, body size and morphology in a monophyletic group of Neotropical pitvipers (Bothrops)
Authors: Martins Marcio , Araujo Marcio S. , Sawaya Ricardo J. , Nunes Renato 
Published: July 2002

AbstractThe Neotropical pitviper genus Bothrops comprises about 40 species, which occur in all main ecosystems of cis‐Andean South America. We explored the relationships of body size and form (tail length and stoutness) with macrohabitat use in 20 forms of Bothrops. Semi‐arboreal habits appeared only in forest forms. Semi‐arboreals are significantly more slender and have longer tails than terrestrials; body size is not significantly different between terrestrials and semi‐arboreals. Within Bothrops, independent contrasts for macrohabitat use were significantly correlated with contrasts of tail size (positively) and stoutness (negatively); thus, the more arboreal the species, the longer its tail and the more slender its body. Contrasts of adult body size seems to remain constant over the lower range of macrohabitat use, but to decrease in species of Bothrops which are more arboreal. Reconstructions of character states indicate that: (1) the ancestor of Bothrops was a small, stout, terrestrial species; (2) semi‐arboreal habits appeared one to three times in the genus; (3) a decrease in stoutness and an increase in tail length occurred along with an increase in arboreality in some clades. Although macrohabitat use seems to be important in determining body form in Bothrops, our results also indicate that tail size, stoutness and body size may also be affected by selective agents other than macrohabitat use. The selective agents responsible for the shifts in macrohabitat use in Bothrops are still uncertain, although they may have included prey availability and/or predation pressure. The plasticity of macrohabitat use, morphology and body size described in this study may have been key features that facilitated the highly successful ecological diversification of Bothrops in South America.
Interactions between the red squirrel (Sciurus vulgaris), great tit (Parus major) and jackdaw (Corvus monedula) whilst using nest boxes
Authors: Shuttleworth C. M. 
Published: July 2002

AbstractThis paper reports upon the use of nest boxes in coniferous woodland by the red squirrel Sciurus vulgaris, great tit Parus major and the jackdaw Corvus monedula over a 6‐year period from 1994 to 1999. Initially 30 nest boxes were erected with eight additional boxes being put up in 1995. In the period 1994 to 1997, red squirrels were found to use nest boxes regularly as nesting and breeding sites (7.8 ± 1.0 se litters found annually). Box use was greatest in the summer and autumn months (70% of boxes being used at least once) and declined through the winter (50%) into the spring (45%). The presence of great tit clutches and broods in the spring did not prevent red squirrels from occupying boxes. Only 28% (n= 12) of all the recorded great tit clutches produced fledgling young in 1994 to 1997 and red squirrels were found to have consumed some of the chicks and eggs. The establishment of a jackdaw colony within the woodland led to 86% of the nest boxes being used by the birds in the spring of 1999. Red squirrel occupation of boxes in the spring declined to 7% and only three litters were recorded that year. The study showed that the jackdaw has the capacity to dominate nest boxes during the spring months despite the high density of red squirrels within the reserve.
Postnatal growth in body length and mass of polar bears (Ursus maritimus) at Svalbard
Authors: Derocher A. E. , Wiig Ø. 
Published: July 2002

AbstractThe von Bertalanffy curve was used to examine growth patterns in both body length and mass of female and male polar bears Ursus maritimus live‐captured near Svalbard, Norway. A longer growth period in males resulted in pronounced sexual dimorphism in both body length and mass. Males were 1.16 times longer and 2.10 times heavier than females. The asymptotic body length of female and male polar bears from Svalbard was smaller than that for polar bears in four of six previously studied populations. Asymptotic body mass of females from Svalbard was lower than other previously studied populations, while males were generally lighter. The reasons for the lighter bears in Svalbard are unclear, but we believe they were not related to sampling error, ecosystem productivity, or genetic differences. The high pollution load of polar bears in Svalbard may have affected body size but this potential factor could not be assessed. The generally smaller size of polar bears in Svalbard was consistent with density‐dependent growth effects but again, information on population density relative to carrying capacity was insufficient to assess this hypothesis.
Three algorithms on Braun trees
Authors: OKASAKI CHRIS 
Published: July 2002

Among the many flavours of balanced binary trees, Braun

trees (Braun and Rem,

1983) are perhaps the most circumscribed. For any given

node of a Braun tree,

the left subtree is either exactly the same size as the

right subtree, or one element

larger. Braun trees always have minimum height, and the

shape of each Braun

tree is completely determined by its size. In return for

this rigor, algorithms that

manipulate Braun trees are often exceptionally simple and

elegant, and need not

maintain any explicit balance information.Braun trees have been used to implement both flexible

arrays (Braun and Rem,

1983; Hoogerwoord, 1992; Paulson, 1996) and priority

queues (Paulson, 1996; Bird,

1996). Most operations involving a single element

(e.g. adding, removing, inspecting

or updating an element) take O(log n) time,

since the trees are balanced. We consider

three algorithmically interesting operations that

manipulate entire trees. First, we

give an O(log2n) algorithm

for calculating the size of a tree. Second, we show how

to create a tree containing n copies of some element

x in O(log n) time. Finally, we

describe an order-preserving algorithm for converting

a list to a tree in O(n) time.

This last operation is not nearly as straightforward

as it sounds!
Final coalgebras as greatest fixed points in ZF set theory
Authors: PAULSON LAWRENCE C. 
Published: July 2002

A special final coalgebra theorem, in the style of Aczel (1988), is proved within standard
Zermelo–Fraenkel set theory. Aczel's Anti-Foundation Axiom is replaced by a variant
definition of function that admits non-well-founded constructions. Variant ordered pairs and
tuples, of possibly infinite length, are special cases of variant functions. Analogues of Aczel's
solution and substitution lemmas are proved in the style of Rutten and Turi (1993). The
approach is less general than Aczel's, but the treatment of non-well-founded objects is
simple and concrete. The final coalgebra of a functor is its greatest fixedpoint.Compared with previous work (Paulson, 1995a), iterated substitutions and solutions are
considered, as well as final coalgebras defined with respect to parameters. The disjoint sum
construction is replaced by a smoother treatment of urelements that simplifies many of the
derivations.The theory facilitates machine implementation of recursive definitions by letting both
inductive and coinductive definitions be represented as fixed points. It has already been
applied to the theorem prover Isabelle (Paulson, 1994).
The use of potential vorticity and water vapour imagery to validate numerical models
Authors: Mansfield D A 
Published: July 2002

AbstractA comparison between potential vorticity (PV) fields and water vapour imagery shows a close relationship in the region of the polar front. Examples are given showing the nature of this relationship and how a mis‐match between the PV and the imagery can be used to detect errors in model analyses and forecasts. The nature of the relationship varies according to the synoptic situation and some of the possible pitfalls encountered by not applying additional checks using model humidity or ‘pseudo imagery’ fields are illustrated. Copyright © 1997 Royal Meteorological Society
Temperature and food quality effects on growth, consumption and post-ingestive utilization ef.ciencies of the forest tent caterpillar Malacosoma disstria (Lepidoptera: Lasiocampidae)
Authors: Levesque K.R. , Fortin M. , Mauffette Y. 
Published: July 2002

AbstractTemperature and food quality can both influence growth rates, consumption rates, utilization efficiencies and developmental time of herbivorous insects. Gravimetric analyses were conducted during two consecutive years to assess the effects of temperature and food quality on fourth instar larvae of the forest tent caterpillar Malacosoma disstria Hübner. Larvae were reared in the laboratory at three different temperatures (18, 24 and 30°C) and on two types of diet; leaves of sugar maple trees Acer saccharum Marsh. located at the forest edge (sun-exposed leaves) or within the forest interior (shade-exposed leaves). In general, larvae reared at 18°C had lower growth rates and lower consumption rates than larvae reared at the warmer temperatures (24 and 30°C). Moreover, the duration of the instar decreased significantly with increasing temperatures. Type of diet also affected the growth rates and amount of food ingested by larvae but did not affect the duration of the instar. Larvae fed sun-exposed leaves consumed more food and gained higher biomasses. Values of approximate digestibility and efficiency of conversion of ingested food were also higher when larvae were fed sun-exposed leaves. Higher growth rates with increasing temperatures were primarily the result of the shorter stadium duration. The higher growth rates of larvae fed sun-exposed leaves were possibly the result of stimulatory feeding and consequently greater food intake and also a more efficient use of food ingested. This study suggests that the performance of M. disstria caterpillars could be enhanced by warmer temperatures and higher leaf quality.
Sequence Diversity and Large-Scale Typing of SNPs in the Human Apolipoprotein E Gene
Authors: Nickerson Deborah A. , Taylor Scott L. , Fullerton Stephanie M. , Weiss Kenneth M. , Clark Andrew G. , Stengård Jari H. , Salomaa Veikko , Boerwinkle Eric , Sing Charles F. 
Published: July 2002

A common strategy for genotyping large samples begins with the characterization of human single nucleotide polymorphisms (SNPs) by sequencing candidate regions in a small sample for SNP discovery. This is usually followed by typing in a large sample those sites observed to vary in a smaller sample. We present results from a systematic investigation of variation at the human apolipoprotein E locus (APOE), as well as the evaluation of the two-tiered sampling strategy based on these data. We sequenced 5.5 kb spanning the entireAPOE genomic region in a core sample of 72 individuals, including 24 each of African-Americans from Jackson, Mississippi; European-Americans from Rochester, Minnesota; and Europeans from North Karelia, Finland. This sequence survey detected 21 SNPs and 1 multiallelic indel, 14 of which had not been previously reported. Alleles varied in relative frequency among the populations, and 10 sites were polymorphic in only a single population sample. Oligonucleotide ligation assays (OLA) were developed for 20 of these sites (omitting the indel and a closely-linked SNP). These were then scored in 2179 individuals sampled from the same three populations (n = 843, 884, and 452, respectively). Relative allele frequencies were generally consistent with estimates from the core sample, although variation was found in some populations in the larger sample at SNPs that were monomorphic in the corresponding smaller core sample. Site variation in the larger samples showed no systematic deviation from Hardy-Weinberg expectation. The large OLA sample clearly showed that variation in many, but not all, of OLA-typed SNPs is significantly correlated with the classical protein-coding variants, implying that there may be important substructure within the classical ɛ2, ɛ3, and ɛ4 alleles. Comparison of the levels and patterns of polymorphism in the core samples with those estimated for the OLA-typed samples shows how nucleotide diversity is underestimated when only a subset of sites are typed and underscores the importance of adequate population sampling at the polymorphism discovery stage.[The sequence data described in this paper have been submitted to the GenBank data library under accession no. AF261279.]
Indole-3-Acetic Acid Metabolism in Lemna gibbaUndergoes Dynamic Changes in Response to Growth Temperature
Authors: Rapparini Francesca , Tam Yuen Yee , Cohen Jerry D. , Slovin Janet P. 
Published: July 2002

Abstract
Auxin is the mobile signal controlling the rate of growth and specific aspects of the development of plants. It has been known for over a century that auxins act as the messenger linking plant development to specific environmental changes. An often overlooked aspect of how this is accomplished is the effect of the environment on metabolism of the major plant auxin, indole-3-acetic acid (IAA). We have studied the metabolism of IAA in relation to one environmental variable, growth temperature. The model system used was an inbred line of the aquatic monocot Lemna gibba G-3, 3F7-11 grown at temperatures ranging from 5°C to 35°C. IAA levels, the rate of IAA turnover, and the patterns of label incorporation from IAA precursors were measured using stable isotope-mass spectrometric techniques and were evaluated relative to growth at the experimental temperatures. IAA levels exhibited unusually high variability in plants grown at 15°C and 20°C. Turnover rates were quite rapid throughout the range of experimental temperatures except at 25°C, where IAA turnover was notably slower. These results suggest that a transition occurred over these temperatures for some aspect of IAA metabolism. Analysis of [15N]anthranilate and [2H5]tryptophan (Trp) incorporation into IAA showed that Trp-dependent biosynthesis predominated at 15°C; however, Trp-independent biosynthesis of IAA was the major route to IAA at 30°C. The effects of growth temperature on auxin levels have been reported previously, but no prior studies correlated these effects with which pathway becomes the primary one for IAA production.
A Metal-Accumulator Mutant of Arabidopsis thaliana
Authors: Delhaize E. 
Published: July 2002

Abstract
A mutation designated man1 (for manganese accumulator) was found to cause Arabidopsis thaliana seedlings to accumulate a range of metals. The man1 mutation segregated as a single recessive locus located on chromosome 3. When grown on soil, mutant seedlings accumulated Mn (7.5 times greater than wild type), Cu (4.6 times greater than wild type), Zn (2.8 times greater than wild type), and Mg (1.8 times greater than wild type) in leaves. In addition to these metals, the man1 mutant accumulated 2.7-fold more S in leaves, primarily in the oxidized form, than wild-type seedlings. Analysis of seedlings grown by hydroponic culture showed a similar accumulation of metals in leaves of man1 mutants. Roots of man1 mutants also accumulated metals, but unlike leaves they accumulated 10-fold more total Fe (symplasmic and apoplasmic combined) than wild-type roots. Roots of man1 mutants possessed greater (from 1.8- to 20-fold) ferric-chelate reductase activity than wild-type seedlings, and this activity was not responsive to changes of Mn nutrition in either genotype. Taken together, these results suggest that the man1 mutation disrupts the regulation of metal-ion uptake or homeostasis in Arabidopsis.
Isolation and Characterization of Glutamine Synthetase from the Marine Diatom Skeletonema costatum
Authors: Robertson D. L. , Alberte R. S. 
Published: July 2002

Abstract
Two peaks of glutamine synthetase (GS) activity were resolved by anion-exchange chromatography from the marine diatom Skeletonema costatum Grev. The second peak of activity accounted for greater than 93% of total enzyme activity, and this isoform was purified over 200-fold. Results from denaturing gel electrophoresis and gel-filtration chromatography suggest that six 70-kD subunits constitute the 400-kD native enzyme. The structure of the diatom GS, therefore, appears more similar to that of a type found in bacteria than to the type common among other eukaryotes. Apparent Michaelis constant values were 0.7 mM for NH4+, 5.7 mM for glutamic acid, and 0.5 mM for ATP. Enzyme activity was inhibited by serine, alanine, glycine, phosphinothricin, and methionine sulfoximine. Polyclonal antiserum raised against the purified enzyme localized a single polypeptide on western blots of S. costatum cell lysates and recognized the denatured, native enzyme. Western analysis of the two peak fractions derived from anion-exchange chromatography demonstrated that the 70-kD protein was present only in the later-eluting peak of enzyme activity. This form of GS does not appear to be unique to S. costatum, since the antiserum recognized a similar-sized protein in cell lysates of other chromophytic algae.