bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gonadal development and mode of sexuality in a coral‐reef damselfish, Dascyllus trimaculatus
Authors: Asoh Kazue , Kasuya Maiko 
Published: July 2002

AbstractThe process of early gonadal development and the mode of sexuality were examined in the three‐spot damselfish Dascyllus trimaculatus. All gonads developed an ovarian lumen and primary‐growth‐stage oocytes after an initially undifferentiated state. From this ovarian state or from more developed ovaries, some gonads redifferentiated into testes. None of 130 individuals examined had a gonad containing degenerating vitellogenic oocytes and proliferating spermatogenic tissue. Nineteen individuals, however, had a gonad containing degenerating cortical–alveolus stage oocytes and proliferating spermatogenic tissue. The size of these individuals overlapped with the female size range in which most females were still in the middle of the maturation process or the smallest female size class in which most females had vitellogenic oocytes. This suggests that the transition toward maleness in these individuals is likely to have occurred after oocytes in their gonads attained cortical–alveolus stage, but before their final maturation and spawning as females, and that the protogynous pattern of gonadal development in D. trimaculatus is non‐functional. The observed protogynous pattern seems to have been present in the common ancestor of the genus and have been retained in this descendant species.
Efficient graph algorithms using lazy monolithic arrays
Authors: JOHNSSON THOMAS 
Published: July 2002

Many, perhaps even most, algorithms that involve data structures
are traditionally
expressed by incremental updates of the data structures. In functional
languages,
however, incremental updates are usually both clumsy and inefficient, especially

when the data structure is an array.In functional languages, we instead prefer to express such array algorithms
using
monolithic arrays – wholesale creation of the final answer
– both for succinctness of
expression, efficiency (only one array created) and (sometimes) implicit
parallelism.
The ease with which the solution can be reformulated of course depends
on the
problem, and varies from trivial (e.g. matrix multiplication), to challenging
(e.g.
solving linear equation systems using Gauss elimination, which in fact
can be done
by creating only two arrays, recursively defined, of which one is the answer).
Other
problems have been notoriously resistant to attack; these usually involve
some
unpredictable processing order of the elements. One such problem is graph
marking,
i.e. marking the nodes reachable from a set of roots. Hitherto, no functional
method
has been known except emulating the traditional imperative solution (King
&
Launchbury, 1995; Launchbury & Peyton Jones, 1995).The contribution of this paper is to show how this problem, and some
related
ones, can be solved using a novel array creation primitive, lazier than
previous ones.
Type-checking injective pure type systems
Authors: BARTHE GILLES 
Published: July 2002

Injective pure type systems form a large class of pure type systems for which one can
compute by purely syntactic means two sorts elmt(Γ[mid ]M) and
sort(Γ[mid ]M), where Γ is a pseudo-context and M is a
pseudo-term, and such that for every sort s,formula hereBy eliminating the problematic clause in the (abstraction) rule in favor of constraints over
elmt(.[mid ].) and sort(.[mid ].), we provide a sound and complete type-checking algorithm for
injective pure type systems. In addition, we prove expansion postponement for a variant of
injective pure type systems where the problematic clause in the (abstraction) rule is replaced
in favor of constraints over elmt(.[mid ].) and sort(.[mid ].).
Contribution of neuroimaging to the differential diagnosis of dementias and other late life
psychiatric disorders
Authors: Förstl H. , Hentschel F. 
Published: July 2002

IntroductionThis is a review of recent and clinically relevant work on neuroimaging and its contribution to the diagnosis of neurodegenerative or other neurological and psychiatric diseases in older patients. Earlier research has been summarized in our previous review. We include publications on cranial computed tomography (CT) and magnetic resonance imaging (MRI), on single photon emission computed tomography (SPECT) and positron emission tomography (PET), electroencephalo-graphy (EEG), and on other methods.
Dominating a Family of Graphs with Small Connected Subgraphs
Authors: CARO YAIR , YUSTER RAPHAEL 
Published: July 2002

Let F = {G1, …, Gt}
be a family of n-vertex graphs defined on the same vertex-set V, and
let k be a positive integer. A subset of vertices D ⊂ V is
called an (F, k)-core if, for each v ∈ V and for each
i = 1, …, t, there are at least k neighbours of v
in Gi that belong to
D. The subset D is called a connected (F, k)-core
if the subgraph induced by D in each Gi
is connected. Let δi be the minimum degree of Gi
and let δ(F) = minti=1δi. Clearly, an
(F, k)-core exists if and only if δ(F) [ges ] k,
and a connected (F, k)-core exists if and only if
δ(F) [ges ] k and each Gi is connected.
Let c(k, F) and cc(k, F)
be the minimum size of an (F, k)-core and a connected (F, k)-core,
respectively. The following asymptotic results are proved for every
t < ln ln δ and k < √lnδ:formula hereThe results are asymptotically tight for infinitely many families F. The results unify and
extend related results on dominating sets, strong dominating sets and connected dominating
sets.
Performance of the ECMWF model in forecasting the tracks of tropical cyclones in the South China Sea and parts of the western North Pacific
Authors: Lam C C 
Published: July 2002

AbstractThe performance of the European Centre for Medium‐Range Forecasts model in forecasting the tracks of tropical cyclones in the South China Sea and parts of the western North Pacific for the years 1991–8 was assessed using 2.5° resolution data transmitted operationally over the WMO Global Telecommunication System. Minimum mean sea level pressure centres were used to identify and track the positions of tropical cyclones, and in 1998 the positions of the centre of maximum 850 hPa relative vorticity were also used. The model's performance was compared with that of subjective forecasts made by the Hong Kong Observatory and with no‐skill forecasts as represented by a climatology‐persistence method in the 1990s. Significant improvements in the model forecasting of tropical cyclone tracks were identified towards the end of that period. The model mean forecast errors for 24‐hour, 48‐hour and 72‐hour positions were 215 km, 340 km and 453 km in the early 1990s (1991–3) respectively, compared with 155 km, 244 km and 292 km in the late 1990s (1996–8). Copyright © 2001 Royal Meteorological Society
Feeding dragons in Komodo National Park: a tourism tool with conservation complications
Authors: Walpole Matthew J. 
Published: July 2002

AbstractLarge carnivores are key visitor attractions in protected areas, but are difficult to see. Thus, supplementary feeding is sometimes used to attract them to viewing sites. Such intervention is contentious but its effects have rarely been examined. This paper analyses a case study of supplementary feeding in Komodo National Park, Indonesia. Using data from daily and annual Komodo dragon censuses, feeding records and financial accounts, the effects of feeding and its cessation on dragon numbers, tourist viewing opportunities and local community benefits were examined. Regular feeding caused dragon numbers to increase at the feeding site, but not year‐round. Cessation of feeding caused numbers to decline again to natural levels. However, tourists were less likely to see dragons at the feeding site after cessation, and local community revenues declined with the loss of a market for goats. Solutions lie in finding less intrusive means for tourists to view dragons, and enabling local people to become involved in tourism through training, recruitment and the development of alternative markets.
Evolution of the Neuropeptide Y Receptor Family: Gene and Chromosome Duplications Deduced from the Cloning and Mapping of the Five Receptor Subtype Genes in Pig
Authors: Wraith Amanda , Törnsten Anna , Chardon Patrick , Harbitz Ingrid , Chowdhary Bhanu P. , Andersson Leif , Lundin Lars-Gustav , Larhammar Dan 
Published: July 2002

Neuropeptide Y (NPY) receptors mediate a variety of physiological responses including feeding and vasoconstriction. To investigate the evolutionary events that have generated this receptor family, we have sequenced and determined the chromosomal localizations of all five presently known mammalian NPY receptor subtype genes in the domestic pig, Sus scrofa (SSC). The orthologs of the Y1 and Y2 subtypes display high amino acid sequence identities between pig, human, and mouse (92%–94%), whereas the Y4, Y5, and y6 subtypes display lower identities (76%–87%). The lower identity of Y5 is due to high sequence divergence in the large third intracellular loop. TheNPY1R, NPY2R, and NPY5R receptor genes were localized to SSC8, the NPY4R to SSC14, andNPY6R to SSC2. Our comparisons strongly suggest that the tight cluster of NPY1R, NPY2R, and NPY5R on human chromosome 4 (HSA4) represents the ancestral configuration, whereas the porcine cluster has been split by two inversions on SSC8. These 3 genes, along with adjacent genes from 14 other gene families, form a cluster on HSA4 with extensive similarities to a cluster on HSA5, whereNPY6R and >13 other paralogs reside, as well as another large cluster on HSA10 that includes NPY4R. Thus, these gene families have expanded through large-scale duplications. The sequence comparisons show that the NPY receptor tripletNPY1R–NPY2R–NPY5R existed before these large-scale duplications.[Sequence data for this article were deposited with the GenBank data library under accession nos.AF106081, PID g6457648 (for Pig Y1 sequence); accession nos. AF106082, PID g4249727 (for Pig Y2 sequence); accession no. AF227955 (for Pig Y4 sequence); accession nos. AF106083, PID g4249729 (for Pig Y5 sequence); accession no. AF227956 (for Pig Y6 sequence).]
Isolation of Lysophosphatidic Acid Phosphatase from Developing Peanut Cotyledons
Authors: Shekar Sunil , Tumaney Ajay W. , Rao T.J.V. Sreenivasa , Rajasekharan Ram 
Published: July 2002

Abstract
The soluble fraction of immature peanut (Arachis hypogaea) was capable of dephosphorylating [3H]lysophosphatidic acid (LPA) to generate monoacylglycerol (MAG). The enzyme responsible for the generation of MAG, LPA phosphatase, has been identified in plants and purified by successive chromatography separations on octyl-Sepharose, Blue Sepharose, Superdex-75, and heparin-agarose to apparent homogeneity from developing peanuts. This enzyme was purified 5,048-fold to a final specific activity of 858 nmol min−1 mg−1. The enzyme has a native molecular mass of approximately 39 kD determined by gel filtration and migrates as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with a subunit molecular mass of 39 ± 1.5 kD. The K m values for oleoyl-, stearoyl-, and palmitoyl-sn-glycerol-3-phosphate were determined to be 28.6, 39.3, and 47.9 μm, respectively. The LPA phosphatase was specific to LPA and did not utilize any other substrate such as glycerol-3-phosphate, phosphatidic acid, orp-nitrophenylphosphate. The enzyme activity was stimulated by the low concentrations of detergents such as Triton X-100 and octylglucoside. Cations had no effect on the enzyme activity. Fatty acids, sphingosine, and sphingomyelin at low concentrations stimulated the enzyme activity. The identification of LPA phosphatase in plants demonstrates the existence of MAG biosynthetic machinery in plants.
Functional Interactions between Heterologously Expressed Starch-Branching Enzymes of Maize and the Glycogen Synthases of Brewer's Yeast
Authors: Seo Beom-seok , Kim Seungtaek , Scott M. Paul , Singletary George W. , Wong Kit-sum , James Martha G. , Myers Alan M. 
Published: July 2002

Abstract
Starch-branching enzymes (SBEs) catalyze the formation of α(1→6) glycoside bonds in glucan polymers, thus, affecting the structure of amylopectin and starch granules. Two distinct classes of SBE are generally conserved in higher plants, although the specific role(s) of each isoform in determination of starch structure is not clearly understood. This study used a heterologous in vivo system to isolate the function of each of the three known SBE isoforms of maize (Zea mays) away from the other plant enzymes involved in starch biosynthesis. The ascomycete Brewer's yeast (Saccharomyces cerevisiae) was employed as the host species. All possible combinations of maize SBEs were expressed in the absence of the endogenous glucan-branching enzyme. Each maize SBE was functional in yeast cells, although SBEI had a significant effect only if SBEIIa and SBEIIb also were present. SBEI by itself did not support glucan accumulation, whereas SBEIIa and SBEIIb both functioned along with the native glycogen synthases (GSs) to produce significant quantities of α-glucan polymers. SBEIIa was phenotypically dominant to SBEIIb in terms of glucan structure. The specific branching enzyme present had a significant effect on the molecular weight of the product. From these data we suggest that SBEs and GSs work in a cyclically interdependent fashion, such that SBE action is needed for optimal GS activity; and GS, in turn, influences the further effects of SBE. Also, SBEIIa and SBEIIb appear to act before SBEI during polymer assembly in this heterologous system.
Biochemical Characterization of the aba2 and aba3 Mutants in Arabidopsis thaliana
Authors: Schwartz S. H. , Leon-Kloosterziel K. M. , Koornneef M. , Zeevaart JAD. 
Published: July 2002

Abstract
Abscisic acid (ABA)-deficient mutants in a variety of species have been identified by screening for precocious germination and a wilty phenotype. Mutants at two new loci, aba2 and aba3, have recently been isolated in Arabidopsis thaliana (L.) Heynh. (K.M. Leon-Kloosterziel, M. Alvarez-Gil, G.J. Ruijs, S.E. Jacobsen, N.E. Olszewski, S.H. Schwartz, J.A.D. Zeevaart, M. Koornneef [1996] Plant J 10: 655–661), and the biochemical characterization of these mutants is presented here. Protein extracts from aba2 and aba3 plants displayed a greatly reduced ability to convert xanthoxin to ABA relative to the wild type. The next putative intermediate in ABA synthesis, ABA-aldehyde, was efficiently converted to ABA by extracts from aba2 but not by extracts from aba3 plants. This indicates that the aba2 mutant is blocked in the conversion of xanthoxin to ABA-aldehyde and that aba3 is impaired in the conversion of ABA-aldehyde to ABA. Extracts from the aba3 mutant also lacked additional activities that require a molybdenum cofactor (Moco). Nitrate reductase utilizes a Moco but its activity was unaffected in extracts from aba3 plants. Moco hydroxylases in animals require a desulfo moiety of the cofactor. A sulfido ligand can be added to the Moco by treatment with Na2S and dithionite. Treatment of aba3 extracts with Na2S restored ABA-aldehyde oxidase activity. Therefore, the genetic lesion in aba3 appears to be in the introduction of S into the Moco.
Developmental Regulation of Pyrroline-5-Carboxylate Reductase Gene Expression in Arabidopsis
Authors: Hua X. J. , van de Cotte B. , Van Montagu M. , Verbruggen N. 
Published: July 2002

Abstract
At-P5R, a gene encoding the last enzyme of the proline (Pro) biosynthetic pathway in Arabidopsis thaliana, is developmentally regulated. To characterize the cis elements responsible for this developmental regulation, a series of 5[prime] deletions of the At-P5R promoter were transcriptionally fused to a β-glucuronidase (GUS)-coding region and transformed into Arabidopsis. The complete promoter of At-P5R directs strong GUS activity in root tips, the shoot meristem, guard cells, hydathodes, pollen grains, ovules, and developing seeds, all of which contain rapidly dividing cells and/or are undergoing changes in osmotic potential. This expression pattern is consistent with the function of Pro as an energy, nitrogen, and carbon source and as an osmoticum in response to dehydration. Promoters longer than 212 base pairs (bp) showed the same expression pattern, whereas those shorter than 143 bp did not direct any detectable GUS activity in any organs. This suggests that a 69-bp promoter region located between -212 and -143 bp is necessary to establish the tissue-specific expression of At-P5R during development. The Pro content measured in different organs suggests that, in addition to transcriptional control of the biosynthetic pathway, the transport of Pro may play a role in its distribution within Arabidopsis. Several aspects of the relationship between Pro metabolism and plant physiology are discussed.
cDNA Clones Encoding 1,3-β-Glucanase and a Fimbrin-Like Cytoskeletal Protein Are Induced by Al Toxicity in Wheat Roots
Authors: Cruz-Ortega R. , Cushman J. C. , Ownby J. D. 
Published: July 2002

Abstract
A cDNA library made from mRNA of Al-treated roots of an Al-sensitive wheat (Triticum aestivum cv Victory) cultivar was screened with a degenerate oligonucleotide probe derived from the partial amino acid sequence of the Al-induced protein TAI-18. Of seven clones that initially hybridized with the probe, one encoded a novel 1,3-β-glucanase having a calculated molecular weight of 46.3 and an isoelectric point of 6.0. Like the A6 1,3-β-glucanase gene products from Brassica napus and Arabidopsis thaliana, the predicted wheat protein had a C-terminal extension with three potential glycosylation sites. Northern analysis revealed that wheat 1,3-β-glucanase mRNA was up-regulated in Al-intoxicated roots, with highest expression after 12 h. The antibody to A6 1,3-β-glucanase from B. napus cross-reacted with a 56-kD protein that was induced after 24 h. A second partial cDNA clone showed similarity to genes encoding cytoskeletal fimbrin-like (actin-bundling) proteins. Although well studied in animals and fungi, fimbrins have not previously been described in plants. Fimbrin-like transcripts were up-regulated after 24 h of Al treatment in the Al-sensitive wheat cv Victory. In the Al-tolerant cv Atlas 66, fimbrin-like mRNA was up-regulated within 12 h by Al concentrations that did not inhibit root growth. Cellular stress associated with Al toxicity therefore causes up-regulation of a defense-related gene and a gene involved in the maintenance of cytoskeletal function.
Characterization and Functional Expression of a Ubiquitously Expressed Tomato Pectin Methylesterase
Authors: Gaffe J. , Tiznado M. E. , Handa A. K. 
Published: July 2002

Abstract
Pectin methylesterase (PME),a ubiquitous enzyme in plants, de-esterifies the methoxylated pectin in the plant cell wall. We have characterized a PME gene (designated as pmeu1) from tomato (Lycopersicon esculentum) with an expression that is higher in younger root, leaf, and fruit tissues than in older tissues. Hypocotyls and epicotyls show higher accumulation of pmeu1 transcripts compared with cotyledons. pmeu1 represents a single-copy gene in the tomato genome. Comparison of the deduced amino acid sequence of pmeu1 with other PME homologs showed that the N-terminal halves are highly variable, and the C-terminal halves are relatively conserved in plant PMEs. Constitutive expression of a fruit-specific PME antisense gene does not affect the level of pmeu1 transcripts in vegetative tissues but does lower the level of PMEU1 mRNA in developing tomato fruits. These results suggest that there exists developmentally regulated silencing of pmeu1 by a heterologous PME antisense gene. Expression of pmeu1 in tobacco (Nicotiana tabacum) under the control of the cauliflower mosaic virus 35S promoter caused up to a 4-fold increase in PME specific activity that was correlated with the accumulation of PMEU1 mRNA. In vitro transcription-translation analyses show that pmeu1 encodes a 64-kD polypeptide, whereas transgenic tobacco plants expressing pmeu1 accumulate a new 37-kD polypeptide, suggesting extensive posttranslational processing of PMEU1. These results are the first evidence, to our knowledge, of the functional characterization of a PME gene and the extensive modification of the encoded polypeptide.
Evidence that the Plant Host Synthesizes the Heme Moiety of Leghemoglobin in Root Nodules1
Authors: Santana Maria A. , Pihakaski-Maunsbach Kaarina , Sandal Niels , Marcker Kjeld A. , Smith Alison G. 
Published: July 2002

Abstract
Although it is well established that the plant host encodes and synthesizes the apoprotein for leghemoglobin in root nodules, the source of the heme moiety has been uncertain. We recently found that the transcript for coproporphyrinogen III oxidase, one of the later enzymes of heme synthesis, is highly elevated in soybean (Glycine maxL.) nodules compared with roots. In this study we measured enzyme activity and carried out western-blot analysis and in situ hybridization of mRNA to investigate the levels during nodulation of the plant-specific coproporphyrinogen oxidase and four other enzymes of the pathway in both soybean and pea (Pisum sativum L.). We compared them with the activity found in leaves and uninfected roots. Our results demonstrate that all of these enzymes are elevated in the infected cells of nodules. Because these are the same cells that express apoleghemoglobin, the data strongly support a role for the plant in the synthesis of the heme moiety of leghemoglobin.
Accumulation of a Clock-Regulated Transcript during Flower-Inductive Darkness in Pharbitis nil1
Authors: Sage-Ono Kimiyo , Ono Michiyuki , Harada Hiroshi , Kamada Hiroshi 
Published: July 2002

Abstract
To clarify the molecular basis of the photoperiodic induction of flowering in the short-day plantPharbitis nil cv Violet, we examined changes in the level of mRNA in cotyledons during the flower-inductive photoperiod using the technique of differential display by the polymerase chain reaction. A transcript that accumulated during the inductive dark period was identified and a cDNA corresponding to the transcript, designated PnC401 (P. nil C401), was isolated. RNA-blot hybridization verified that levels ofPnC401 mRNA fluctuated with a circadian rhythm, with maxima between 12 and 16 h after the beginning of the dark period) and minima of approximately 0. This oscillation continued even during an extended dark period but was damped under continuous light. Accumulation of PnC401 mRNA was reduced by a brief exposure to red light at the 8th h of the dark period (night-break treatment) or by exposure to far-red light at the end of the light period (end-of-day far-red treatment). These results suggest that fluctuations in levels of PnC401 mRNA are regulated by phytochrome(s) and a circadian clock and that they are associated with photoperiodic events that include induction of flowering.
Reversibility of H+-ATPase and H+-Pyrophosphatase in Tonoplast Vesicles from Maize Coleoptiles and Seeds1
Authors: Rocha Façanha Arnoldo , de Meis Leopoldo 
Published: July 2002

Abstract
Tonoplast-enriched vesicles isolated from maize (Zea mays L.) coleoptiles and seeds synthesize ATP from ADP and inorganic phosphate (Pi) and inorganic pyrophosphate from Pi. The synthesis is consistent with reversal of the catalytic cycle of the H+-ATPase and H+-pyrophosphatase (PPase) vacuolar membrane-bound enzymes. This was monitored by measuring the exchange reaction that leads to32Pi incorporation into ATP or inorganic pyrophosphate. The reversal reactions of these enzymes were dependent on the proton gradient formed across the vesicle membrane and were susceptible to the uncoupler carbonyl cyanidep(trifluoromethoxy)-phenylhydrazone and the detergent Triton X-100. Comparison of the two H+ pumps showed that the H+-ATPase was more active than H+-PPase in coleoptile tonoplast vesicles, whereas in seed vesicles H+-PPase activity was clearly dominant. These findings may reflect the physiological significance of these enzymes in different tissues at different stages of development and/or differentiation.