bluuebunny/crossref_metadata_2025_split huggingface dataset:
Auditory scene analysis based on time‐frequency integration of shared FM and AM (II): Optimum time‐domain integration and stream sound reconstruction
Authors: Abe Mototsugu , Ando Shigeru 
Published: September 2002

AbstractIn the preceding paper, we have proposed a method for auditory scene analysis, in which the instantaneous frequency, frequency change rate, and amplitude change rate in time‐frequency space are intensified into a multipeak probability density distribution by voting method and the grouping into streams of mixed sounds is realized. In this paper, as the main point of the second half of this method, we will introduce the assumption that the stream parameters vary slowly according to the known dynamics and propose an integration method on the time axis, in which the probability density distribution of the stream parameters is optimally estimated in time series by a nonparametric Kalman filter. By doing so, the mechanism of higher auditory scene analysis such as enhancement of the accuracy of the stream parameters, interpolation and connection of the breaks of the streams, and introduction of a priori knowledge into stream selection can be realized. Moreover, the separation and reconstruction system of sounds which correspond to streams is constructed, and the proposed technique is verified by fundamental experiments for synthesized sounds or musical sounds and voices. © 2002 Wiley Periodicals, Inc. Syst Comp Jpn, 33(10): 83–94, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1160
Efficiency comparisons of rank and permutation tests based on summary statistics computed from repeated measures data
Authors: Weinberg Janice M. , Lagakos Stephen W. 
Published: September 2002

AbstractA popular method of using repeated measures data to compare treatment groups in a clinical trial is to summarize each individual's outcomes with a scalar summary statistic, and then to perform a two‐group comparison of the resulting statistics using a rank or permutation test. Many different types of summary statistics are used in practice, including discrete and continuous functions of the underlying repeated measures data. When the repeated measures processes of the comparison groups differ by a location shift at each time point, the asymptotic relative efficiency of (continuous) summary statistics that are linear functions of the repeated measures has been determined and used to compare tests in this class. However, little is known about the non‐null behaviour of discrete summary statistics, about continuous summary statistics when the groups differ in more complex ways than location shifts or where the summary statistics are not linear functions of the repeated measures. Indeed, even simple distributional structures on the repeated measures variables can lead to complex differences between the distribution of common summary statistics of the comparison groups. The presence of left censoring of the repeated measures, which can arise when these are laboratory markers with lower limits of detection, further complicates the distribution of, and hence the ability to compare, summary statistics. This paper uses recent theoretical results for the non‐null behaviour of rank and permutation tests to examine the asymptotic relative efficiencies of several popular summary statistics, both discrete and continuous, under a variety of common settings. We assume a flexible linear growth curve model to describe the repeated measures responses and focus on the types of settings that commonly arise in HIV/AIDS and other diseases. Copyright © 2001 John Wiley & Sons, Ltd.
Preferential action of gabapentin and pregabalin at P/Q‐type voltage‐sensitive calcium channels: Inhibition of K+‐evoked [3H]‐norepinephrine release from rat neocortical slices
Authors: Dooley David J. , Donovan Cindy M. , Meder Wolfgang P. , Whetzel Steven Z. 
Published: September 2002

AbstractGabapentin (GBP; Neurontin®) and pregabalin (PGB; CI‐1008), efficacious drugs in several neurological and psychiatric disorders, inhibit neurotransmitter release from mammalian brain slices at therapeutically relevant concentrations. A detailed investigation, exploring the basis for this in vitro phenomenon, focused on norepinephrine (NE) and rat neocortical tissue in complementary assays of neurotransmitter release and radioligand binding. The results are consistent with the hypothesis that GBP, PGB, and related substances decrease neocortical NE release by acting at the α2δ subunit of presynaptic P/Q‐type voltage‐sensitive Ca2+ channels (VSCC) subserving Ca2+ influx in noradrenergic terminals. The inhibitory action appears competitive with [Ca2+]o and preferential to those neurons undergoing prolonged depolarization. Other results indicate that the reduction of exocytotic NE release is independent of L‐ and N‐type VSCC, classical drug/peptide binding sites on VSCC, Na+ channels, α2‐adrenoceptors, NE transporter, and system L amino acid transporter. These findings suggest a selective modulation of P/Q‐type VSCC that are implicated in neurotransmission and several GBP‐responsive pathologies. Synapse 45:171–190, 2002. © 2002 Wiley‐Liss, Inc.
Sex differences in [123I]β‐CIT SPECT measures of dopamine and serotonin transporter availability in healthy smokers and nonsmokers
Authors: Staley Julie K. , Krishnan‐Sarin Suchitra , Zoghbi Sami , Tamagnan Gilles , Fujita Masahiro , Seibyl John P. , Maciejewski Paul K. , O'Malley Stephanie , Innis Robert B. 
Published: September 2002

AbstractNicotine and other constituents of tobacco smoke elevate dopamine (DA) and serotonin (5‐HT) levels in brain and may cause homeostatic adaptations in DA and 5‐HT transporters. Since sex steroids alter DA and 5‐HT transporter expression, the effects of smoking on DA and 5‐HT transporter availability may differ between sexes. In the present study, DA and 5‐HT transporter availabilities were quantitated using single photon emission computed tomography (SPECT) imaging approximately 22 h after bolus administration of [123I]β‐CIT, an analog of cocaine which labels DA and 5‐HT transporters. Forty‐two subjects including 21 pairs of age‐, race‐, and gender‐matched healthy smokers and nonsmokers (12 female and 9 male pairs) were imaged. Regional uptake was assessed by the outcome measures, V3″, which is the ratio of specific (i.e., ROI‐cerebellar activity) to nondisplaceable (cerebellar) activity, and V3, the ratio of specific to free plasma parent. Overall, striatal and diencephalic [123I]β‐CIT uptake was not altered by smoking, whereas brainstem [123I]β‐CIT uptake was modestly higher (10%) in smokers vs. nonsmokers. When subgrouped by sex, regardless of smoking status, [123I]β‐CIT uptake was higher in the striatum (10%), diencephalon (15%), and brainstem (15%) in females vs. males. The sex*smoking interaction was not significant in the striatum, diencephalon, or brainstem, despite the observation of 20% higher brainstem [123I]β‐CIT uptake in male smokers vs. nonsmokers and less than a 5% difference between female smokers and nonsmokers. The results demonstrate higher DA and 5‐HT transporter availability in females vs. males and no overall effect of smoking with the exception of a modest elevation in brainstem 5‐HT transporters in male smokers. Although these findings are preliminary and need validation with a more selective 5‐HT transporter radiotracer, the results suggest that brainstem 5‐HT transporters may be regulated by smoking in a sex‐specific manner. Synapse 41:275–284, 2001. © 2001 Wiley‐Liss, Inc.
Promoting understanding of chemical bonding and spontaneity through student explanation and integration of ideas
Authors: Teichert Melonie A. , Stacy Angelica M. 
Published: September 2002

AbstractThis article explores the effectiveness of intervention discussion sections for a college general chemistry course designed to apply research on student preconceptions, knowledge integration, and student explanation. Two interventions, on bond energy and spontaneity, were tested and intervention student performance was compared with that of a control group that did not use the experimental pedagogy. Results indicate that this instruction, which identifies students' initial conceptions and integrates those ideas into class discussion, leads to enhanced conceptual understanding. The intervention group outperformed the control group on a written course midterm, the thermodynamics portion of a standardized American Chemical Society examination, and an in‐depth interview. In interviews, the intervention group students explained the energetics of bond breaking and formation at a more sophisticated level than did the control students. In contrast, control students were more tenuous in their thinking, tended to contradict themselves more when discussing bond energy, and harbored more misconceptions about spontaneity. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 464–496, 2002
Complete nutrient composition of commercially raised invertebrates used as food for insectivores
Authors: Finke Mark D. 
Published: September 2002

AbstractA variety of invertebrates are commonly fed to insectivorous animals by both zoos and hobbyists, but information as to the nutrient composition of most commercially raised species is limited. Adult house crickets, house cricket nymphs (Acheta domesticus), superworms (Zophobas morio larvae), giant mealworm larvae, mealworm larvae and adult mealworms (Tenebrio molitor), waxworm larvae (Galleria mellonella), and silkworm larvae (Bombyx mori) were analyzed for moisture, crude protein, crude fat, ash, acid detergent fiber (ADF), neutral detergent fiber (NDF), minerals, amino acids, fatty acids, and vitamins. Earthworms (Lumbricus terresstris) were analyzed for moisture, crude protein, crude fat, ash, ADF, NDF, minerals, amino acids, and vitamins A and D3. Proximate analyses were variable, with wide ranges found for moisture (57.9–83.6%), crude protein (9.3–23.7%), crude fat (1.6–24.9%), ADF (0.1–7.4%), NDF (0.0–11.5%), and ash (0.6–1.2%). Energy content ranged from a low of 674 kcal/kg for silkworms to 2,741 kcal/kg for waxworms.Using an amino acid scoring pattern for rats, the first limiting amino acid for all invertebrates tested was the total sulfur amino acid methionine+cystine. Deficiencies by nutrient (% of samples deficient vs. NRC requirements for rats on a dry matter (DM) basis) were as follows: calcium (100%), vitamin D3 (100%), vitamin A (89%), vitamin B12 (75%), thiamin (63%), vitamin E (50%), iodine (44%), manganese (22%), methionine‐cystine (22%), and sodium (11%). Deficiencies by invertebrate species (number of nutrients deficient vs. the NRC requirements for rats on a DM basis) were as follows: waxworms (9), superworms (8), giant mealworm larvae (7), adult mealworms (6), mealworm larvae (5), adult house crickets (4), house cricket nymphs (4), silkworms (4), and earthworms (4). These data provide a basis for determining nutrient intake of captive insectivores, and will aid in the development of gut‐loading diets to provide captive insectivorous animals with appropriate levels of necessary nutrients. Zoo Biol 21:269–285, 2002. © 2002 Wiley‐Liss, Inc.
Polycoccum crespoae sp. nov., the first report of a lichenicolous fungus on Chondropsis semiviridis (Parmeliaceae)
Authors: Váczi P. , Hawksworth D.L. 
Published: September 2002

AbstractPolycoccum crespoae sp. nov. is described from thalli of Chondropsis semiviridis collected in Australia (Victoria). It has consistently 4-spored asci but differs from known 4-spored species in the size and shape of the ascospores. Attention is also drawn to another undescribed Polycoccum found on another genus of Parmeliaceae, Karoowia adhaerens, from South Africa (Cape Province).
Correlations Among Charcoal Records of Fires from the Past 16,000 Years in Indonesia, Papua New Guinea, and Central and South America
Authors: Haberle Simon G. , Ledru Marie-Pierre 
Published: September 2002

AbstractMicroscopic charcoal preserved in lake and swamp sediments from 10 sites in Indonesia and Papua New Guinea and from 5 sites in Central and South America have been used to reconstruct long-term fire histories for these two regions. Comparison of these records demonstrates that fire is promoted during periods of rapid climate change and high climate variability, regardless of the presence or absence of humans. Broad synchrony of changes in corrected charcoal values in each region supports an atmospheric transmission of the climate signal via the dominant large-scale atmospheric circulation systems (Walker Circulation) that appears to have persisted since 16,000 cal yr B.P. Altered climate boundary conditions under the influence of changing El Niño-related variability, insolation, sea level, and sea surface temperature all influenced the strength of this connection. Correlation of biomass burning records between the regions tends to increase in the Holocene. The main period of inverse correlation occurs during the Younger Dryas Stade, when extratropical climate most affected the tropics. The strongest correlation between the two regions postdates 5000 cal yr B.P., when El Niño-related variability intensified. Fluctuations in tropical biomass burning are at least partly controlled by orbital forcing (precession), although extratropical climate influences and human activity are also important.
Structure—function relationships in the integument of Salamandra salamandra during ontogenetic development
Authors: Pederzoli Aurora , Gambarelli A. , Gabbay Shosh , Rozman A. , Katz U. 
Published: September 2002

AbstractMorphological, cytological and transport properties of the integument of Salamandra salamandra were investigated during natural ontogenetic development, from birth to adult. Three stages were operationally defined: I, larvae, from birth to metamorphosis; II, metamorphosis (judged externally by the colour change and loss of the gills); and III, post‐metamorphosis to adult. Pieces of skin were fixed at various stages for immunocytochemical examinations, and the electrical properties were investigated on parallel pieces. Distinct cellular changes take place in the skin during metamorphosis, and lectin (PNA, WGA and ConA) binding indicates profound changes in glycoprotein composition of cell membranes, following metamorphosis. Band 3 and carbonic anhydrase I (CA I) were confined to mitochondria‐rich (MR)‐like cells, and were detected only in the larval stage. CA II on the other hand, was detected both in MR‐like and in MR cells following metamorphosis. The electrical studies show that the skin becomes more tight (transepithelial resistance increases) upon metamorphosis, followed by manifestation of amiloride‐sensitive short‐circuit current (I sc) indicating that functional Na+ uptake has been acquired. The skin of metamorphosed adults had no finite transepithelial Cl− conductance, and band 3 was not detected in its MR cells. The functional properties of MR‐like and MR cells remain to be established.
Endocytic prolactin routes to the secretory pathway in lactating mammary epithelial cells
Authors: Seddiki Touria , Delpal Serge , Aubourg Alain , Durand Georges , Ollivier‐Bousquet Michèle 
Published: September 2002

AbstractPlasma‐borne prolactin is carried from blood to milk by transcytosis across the mammary epithelial cell through the endocytic and secretory pathways. To determine the precise route of prolactin endocytosis, intracellular transport of biotinylated prolactin was monitored, in parallel with endocytosis of fluorescein isothiocyanate‐conjugated dextran and IgG, by using pulse‐chase experiments in lactating mammary fragments and in enzymatically dissociated acini. Biotinylated prolactin was sorted to vesiculo‐tubular organelles whereas dextran was very rapidly carried to the lumen and IgG remained accumulated in the basal region of cells. To determine whether prolactin uses routes into and across the Golgi and trans‐Golgi network, localisation of biotinylated prolactin was combined with the immunofluorescence detection of caseins and, respectively, p58 and TGN38. Biotinylated prolactin strongly colocalised with caseins during a chase but not all or only very little with p58 and TGN38. To characterise the organelles involved in transcytosis, gold‐labelled prolactin, experimentally accumulated in late endosomes and which recovered a normal transport, was localised by electron microscopy. In mammary fragments incubated at low temperature, and in mammary fragments from rats fed with a lipid‐deprived diet, transport of gold‐labelled prolactin was restored by increasing the temperature and by adding arachidonic acid, respectively. These data demonstrate that a sorting occurs very rapidly between prolactin, dextran and IgG. They suggest that prolactin may reach the biosynthetic pathway after direct fusion between multivesicular bodies and secretory vesicles.
Extracellular matrix development during differentiation into adipocytes with a unique increase in type V and VI collagen
Authors: Nakajima Ikuyo , Muroya Susumu , Tanabe Ryo‐Ichi , Chikuni Koichi 
Published: September 2002

AbstractIn order to study how adipose conversion affects the extracellular environment, levels of extracellular matrix (ECM) proteins during differentiation were analyzed by 125I‐labeled antibody binding to each specific primary antibody. When confluent bovine intramuscular preadipocytes (BIP) were stimulated with adipogenic medium, there was a significant accretion on the cell surface of type I—VI collagens, laminin and fibronectin, compared with undifferentiated cells. The deposition amount of ECM proteins had reached near maximal levels at an early stage of differentiation and lasted throughout the culture. However, the increasing manners were not all the same in these eight proteins. Type V and type VI collagen tended to show a transient decline after the rapid rise at the beginning of stimulation, and fibronectin instead, subsequently decreased. Further analysis by immunocytochemical staining showed that remodeling occurred in type V and VI collagen matrices during this period; extensive fibrillar networks seen at 10 d after stimulation were quite unlike that formed earlier. These specific increases and development of matrix during adipocyte differentiation imply some significance for organizing fat lobules in each ECM proteins, especially type V and VI collagens.
Mac1, a fission yeast transmembrane protein localizing to the poles and septum, is required for correct cell separation at high temperatures
Authors: Grandin Nathalie , Charbonneau Michel 
Published: September 2002

AbstractSchizosaccharomyces pombe represents a genetic model system for studying cell polarity and division in eukaryotes. We report here the identification of Mac1, a novel fission yeast protein that localized predominantly to the cell tips and septum. Sequences corresponding to roughly the first 180 amino acids of Mac1, which exhibited weak homology to the transmembrane domains of the Aspergillus PalI protein 〚Mol. Microbiol. 30 (1998) 259〛, were found to specify localization to the cell periphery. The other 574 amino acids of Mac1 localized to the cytoplasm when expressed alone, thus suggesting that the N‐terminal part of Mac1 functions as a plasma membrane anchor for the rest of the protein. In pom1 null mutant cells, which never switch from unipolar to bipolar growth but, instead, grow exclusively at the randomly chosen end 〚Genes Dev. 12 (1998) 1356〛, Mac1 was, nevertheless, found at both poles, thus suggesting that Mac1 does not specifically localize to the sites of growth. mac1 null mutant cells had no overt phenotype at 22–32 °C, but, nevertheless, displayed a marked decrease in viability at 34–36 °C, accompanied by severe separation defects. Overexpression of mac1 resulted in similar defects. Our data suggest that a correct dosage of Mac1 is needed for correct cell separation at elevated temperatures of growth.
The mitotic spindle and associated membranes in the closed mitosis of trichomonads
Authors: Ribeiro Karla Consort , Pereira‐Neves Antonio , Benchimol Marlene 
Published: September 2002

AbstractIn the present work, we followed the several phases of Tritrichomonas foetus and Trichomonas vaginalis cell cycles using immunofluorescence, serial thin sections, three‐dimensional (3D) reconstruction, and transmission electron microscopy. In motile trichomonad cells or in pseudocyst forms, the nuclear envelope persists throughout mitosis, and the spindle is extranuclear. We found three types of spindle microtubules: pole‐to‐nucleus microtubules which are attached to the nuclear envelope, pole‐to‐pole microtubules forming a cylindrical, cytoplasmic groove on the nuclear compartment in pseudocysts of T. foetus cells, and pole‐to‐cytosol microtubules which extend freely into the cytoplasm. We demonstrated that: (1) in T. foetus, the spindle is assembled from an MTOC located at the base of the costa, underneath one of the basal bodies; (2) the spindle presents an unusual arc shape during the initial phases of mitosis in motile trophozoites; (3) the spindle microtubules are glutamylated, but not acetylated; (4) several membranes similar to those of the endoplasmic reticulum follow the spindle microtubules; (5) finger‐like projections extend from the nucleus towards the cell poles in pseudocysts and multinucleated cells; and (6) vesicles formed in between the two nuclear membranes are seen in the course of mitosis in both trophozoite and pseudocyst forms.
Subcellular distribution of the acidic ribosomal P‐proteins from Saccharomyces cerevisiae in various environmental conditions
Authors: Boguszewska Aleksandra , Tchórzewski Marek , Dukowski Piotr , Winiarczyk Stanisław , Grankowski Nikodem 
Published: September 2002

AbstractThe yeast ribosomal “stalk”–a lateral protuberance on the 60S subunit—consists of four acidic P‐proteins, P1A, P1B, P2A and P2B, which play an important role during protein synthesis. Contrary to most ribosomal proteins, which are rapidly degraded in the cytoplasm, P‐proteins are found as a cytoplasmic pool and are exchanged with the ribosome‐bound proteins during translation. As yet, subcellular trafficking of P‐proteins has not been extensively investigated. Therefore, we have characterized—using immunological approaches—the cellular distribution of P‐proteins in several environmental conditions, characteristic of yeast cells, such as growth phases, and heat‐, osmotic‐, and oxygen‐stress. Using the western blotting approach, we have shown P‐proteins to be present in constant amounts on the ribosomes, despite their exchangeability with the cytoplasmic pool, and regardless of environmental conditions. On the other hand, P‐protein level in the cytoplasm decreased sharply throughout the consecutive growth phases, but was not affected by several stress conditions. Applying the electron microscopic technique and immunogold labeling, we have found that P‐proteins are located in two cell compartments. The first one is the cytoplasm and the second one—an unexpected place—the cell wall, where P‐proteins are fully phosphorylated. Moreover, the existence of P‐proteins on the cellular wall is not affected by various environmental conditions.