bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design, implementation and verification through a real‐time test‐bed of a multi‐rate CDMA adaptive interference mitigation receiver for satellite communication
Authors: Fanucci Luca , De Gaudenzi Riccardo , Giannetti Filippo , Luise Marco , Rovini Massimo 
Published: January 2003

AbstractThis paper presents the design, the implementation, and the main performance results of a multi‐rate code division multiple access (CDMA) interference mitigation receiver for satellite communication. Such activity was performed within a research project supported by the European Space Agency (ESA), whose aim was to demonstrate the suitability of the linear adaptive interference mitigation detector (IMD) named extended complex‐valued blind anchored interference‐mitigating detector (EC‐BAID) for single‐user detection of a CDMA signal in third‐generation (3G) satellite networks. Such a detector, which exhibits a remarkable robustness to multiple access interference, operates in a blind mode, i.e. it only requires knowledge of the timing of the wanted user's signature code, and is therefore very well suited for integration into handheld user terminals.Experimental results in terms of bit error rate with respect to the theoretical behaviour were derived through a specifically developed test bed. Signal plus multiple access interference generation is performed via a computer‐controlled arbitrary waveform generator, followed by frequency up‐conversion to the standard intermediate frequency of 70 MHz. Additive white Gaussian noise is then injected with the aid of a precision noise generator. The core of the test bed is a flexible digital receiver prototype featuring the EC‐BAID detector plus all functions ancillary to IMD (multi‐rate front‐end, automatic gain control, code acquisition and tracking, carrier synchronization, etc.). Those functions were implemented through careful mixing of different technologies: field programmable gate arrays (FPGAs) for computing‐intensive signal processing functions, digital signal processor (DSP) for housekeeping and monitoring, and application specific integrated circuit (ASIC) for adaptive IMD. The adopted design flow also allows an easy re‐use of the prototype architecture to come to an overall integration of the receiver into a single ASIC with modest complexity and power consumption increase with respect to a conventional detector. Copyright © 2003 John Wiley & Sons, Ltd.
Regulation of CRE‐mediated transcription in mouse brain by amphetamine
Authors: Shaw‐Lutchman Tamara Z. , Impey Soren , Storm Daniel , Nestler Eric J. 
Published: January 2003

AbstractPrevious work has demonstrated that acute and chronic administration of amphetamine causes phosphorylation of the transcription factor CREB, the cAMP response element (CRE) binding protein, in striatum, a brain region important for the behavioral actions of the drug. To determine whether such phosphorylation is associated with changes in CREB transcriptional activity, we mapped β‐galactosidase (β‐gal) expression in a CRE‐LacZ transgenic mouse, in which the β‐gal reporter is downstream of CRE sequences, following acute or chronic amphetamine administration. We found that acute amphetamine induced β‐gal expression in a relatively small number of brain regions, including nucleus accumbens (ventral striatum), amygdala, ventral tegmental area, and locus coeruleus. Chronic amphetamine generally produced greater changes in CRE‐mediated transcription in most brain regions and induced CRE‐transcription in several regions unaffected by acute drug exposure. Interestingly, amphetamine regulation of CRE activity differed dramatically between males and females. In nucleus accumbens, β‐gal expression colocalized predominantly with dynorphinergic neurons after acute amphetamine administration, while chronic administration induced β‐gal expression in both dynorphinergic and enkephalinergic neurons. In ventral tegmental area, acute and chronic amphetamine induced β‐gal expression mainly in dopaminergic neurons, while induction in the locus coeruleus occurred mainly in nonnoradrenergic neurons. This study identifies several brain regions where CRE‐mediated transcription may play a key role in the development of neuronal plasticity associated with amphetamine administration. Synapse 48:10–17, 2003. © 2003 Wiley‐Liss, Inc.
Electrophysiological and pharmacological characteristics of nigral dopaminergic neurons in the conscious, head‐restrained rat
Authors: Fà Mauro , Mereu Giampaolo , Ghiglieri Veronica , Meloni Alessandra , Salis Paola , Gessa Gian Luigi 
Published: January 2003

AbstractExtracellular single‐unit recordings of nigral dopamine (DA) neurons were obtained from conscious rats habituated to having their body suspended in a cloth jacket and their head immobilized in the stereotaxic frame by means of a “restraining platform” permanently fixed to the skull. The electrophysiological characteristics of DA neurons from head‐restrained rats and their responses to apomorphine and haloperidol were compared with single‐unit recordings obtained from rats lightly and deeply anesthetized with chloral hydrate and from mesencephalic slices. Head‐restrained rats showed a higher number of spontaneously active DA neurons and a higher percentage of bursting neurons than lightly and deeply anesthetized rats. Indeed, bursting activity was rare in deeply anesthetized rats and was totally absent in slices. Haloperidol was more potent and effective in stimulating the firing rate and bursting activity in head‐restrained than in lightly anesthetized rats, while it was virtually ineffective in deeply anesthetized rats and totally ineffective in slices. On the other hand, DA neurons in head‐restrained rats showed the same average firing rate as DA neurons in lightly and deeply anesthetized rats and in slices. The potency of apomorphine in inhibiting the firing rate, and that of haloperidol in reversing apomorphine effect, did not vary among the different in vivo preparations. The results suggest that chloral hydrate anesthesia blunts or suppresses not only the excitatory inputs which normally sustain the number of spontaneously active DA neurons and their bursting activity, but also the feedback excitation of DA neurons following haloperidol‐induced D2 receptor blockade. On the other hand, chloral hydrate anesthesia modifies neither D2 autoreceptor sensitivity to apomorphine and haloperidol nor the automatic genesis of action potentials. The head‐restrained rat appears to be an important model for studies into the pharmacology and physiology of DA neurons. Synapse 48:1–9, 2003. © 2003 Wiley‐Liss, Inc.
Graphical analysis of 2‐[18F]FA binding to nicotinic acetylcholine receptors in rhesus monkey brain
Authors: Chefer Svetlana I. , London Edythe D. , Koren Andrei O. , Pavlova Olga A. , Kurian Varughese , Kimes Alane S. , Horti Andrew G. , Mukhin Alexey G. 
Published: January 2003

AbstractExternal imaging of nicotinic acetylcholine receptors (nAChRs) using techniques such as PET would help to clarify the roles of these receptors in the physiology and pathology of brain function. Here we report the results of quantitative PET studies of cerebral nAChRs with 2‐[18F]fluoro‐A‐85380 (2‐[18F]FA) in rhesus monkeys. Data from dynamic PET scans were analyzed using graphical methods. Binding potential (BP) values of 2.0, 0.4, 0.3, and 0.03 observed in the thalamus (Th), cortex (Cx), striatum (Str), and cerebellum (Cb), respectively, were consistent with the pattern of α4β2 nAChR distribution in monkey brain. The high value of 2‐[18F]FA‐specific binding in the rhesus monkey Th and low level of that in Cb compared with nonspecific accumulation of radioactivity in these structures allowed use of Cb as a reference region for calculation of BP and volume of distribution of specific binding (VDsb) in Th by graphical methods, both with and without the plasma input function. In contrast, estimation of 2‐[18F]FA specific binding in low‐receptor‐density regions such as Cx and Str required assessment of nondisplaceable volume of distribution (VDnd) in a separate study and measurement of nonmetabolized radioligand concentrations in the plasma. For accurate quantitation of 2‐[18F]FA‐specific binding by graphical analysis, PET studies should last up to 7 h due to the slow kinetics of 2‐[18F]FA brain distribution. Further, to avoid substantial underestimation in measured BP values the doses of administered 2‐[18F]FA should not exceed 0.1 nmol/kg body weight. The findings suggest that 2‐[18F]FA is a promising ligand for quantitation of nAChRs in human brain. Synapse 48:25–34, 2003. Published 2003 Wiley‐Liss, Inc.
Role of phosphatidylinositol 3‐phosphate in formation of forespore membrane in Schizosaccharomyces pombe
Authors: Onishi Masayuki , Koga Takako , Morita Rika , Nakamura Yoko , Nakamura Taro , Shimoda Chikashi , Takegawa Kaoru , Hirata Aiko , Fukui Yasuhisa 
Published: January 2003

AbstractPhosphatidylinositol (PI) 3‐kinase (encoded by the pik3+ gene) in Schizosaccharomyces pombe has been identified as a homologue of VPS34p, a protein required for proper vesicular protein sorting. The clone defective in this protein carries enlarged vacuoles and exhibits sensitivity to high temperature or high ion concentration. The effect of disruption of pik3+ on sporulation of Sz. pombe was examined. The diploid cells underwent G1 arrest and meiosis. However, the spores formed by the Δpik3 cells were not viable. Electron‐microscopic analysis revealed that the growth of the forespore membrane of Δpik3 cells was not correctly orientated, failing to engulf the nucleus or forming extremely small spores, as was confirmed by the use of Spo3p–GFP and GFP–Psy1p, which are markers of the forespore membrane. The coating materials found along the forespore membrane of the wild‐type were greatly reduced in these cells. PI 3‐P, the product of Pik3p, was detected on the forespore membrane, suggesting that PI 3‐P‐dependent vesicle transport may take place in formation of the forespore membrane. Misshaped forespore membrane, accumulation of vesicles, formation of small non‐viable spores, and suppression by over expression of Psy1p were the phenotypes commonly seen in Δpik3 and Δspo3 cells, suggesting a relationship between the functions of Pik3p and Spo3p in formation of the forespore membrane in Sz. pombe. Copyright © 2003 John Wiley & Sons, Ltd.
Transcription patterns of PMA1 and PMA2 genes and activity of plasma membrane H+‐ATPase in Saccharomyces cerevisiae during diauxic growth and stationary phase
Authors: Fernandes Alexandra R. , Sá‐Correia Isabel 
Published: January 2003

AbstractPMA1 and PMA2 genes encode Saccharomyces cerevisiae plasma membrane H+‐ATPase (PM‐H+‐ATPase), an enzyme with critical physiological roles both in the absence or presence of environmental stress. The two PM‐H+‐ATPase isoforms differ in their biochemical characteristics but, under all the growth conditions that were examined so far, PMA2 expression is negligible and Pma1p accounts for practically the totality of cell PM‐H+‐ATPase activity. In the present work, we have compared gene expression levels and activity of this proton pump in yeast cells cultivated under fermentative or respiratory growth and under carbon starvation. The expression levels of both PMA1 and PMA2 genes were consistently higher (2.5–4.5‐fold) in cells cultivated under respiratory metabolism (in ethanol‐based medium or after the diauxic shift), than in cells cultivated under fermentative metabolism (during the full period of growth in a medium where glucose is not the limiting nutrient or during the first period of diauxic growth in low‐glucose‐based medium). The moderate upregulation of PMA1 and PMA2 transcription in cells grown on ethanol compared with those grown on glucose was reflected in the increased content and activity of PM‐H+‐ATPase. In diauxic growth, during transition to stationary phase after ethanol depletion, a further strong activation (eight‐fold) of PMA2 gene transcription was observed. Although PMA2 transcription still remains quite below (20‐fold) PMA1 transcription, this is the first environmental condition, identified so far, that leads to a significant PMA2 expression, suggesting that this PM‐H+‐ATPase isoform may play some role during carbon starvation. Copyright © 2003 John Wiley & Sons, Ltd.
Transcriptome characterization of the dimorphic and pathogenic fungus Paracoccidioides brasiliensis by EST analysis
Authors: Felipe M. S. S. , Andrade R. V. , Petrofeza S. S. , Maranhão A. Q. , Torres F. A. G. , Albuquerque P. , Arraes F. B. M. , Arruda M. , Azevedo M. O. , Baptista A. J. , Bataus L. A. M. , Borges C. L. , Campos E. G. , Cruz M. R. , Daher B. S. , Dantas A. , Ferreira M. A. S. V. , Ghil G. V. , Jesuino R. S. A. , Kyaw C. M. , Leitão L. , Martins C. R. , Moraes L. M. P. , Neves E. O. , Nicola A. M. , Alves E. S. , Parente J. A. , Pereira M. , Poças‐Fonseca M. J. , Resende R. , Ribeiro B. M. , Saldanha R. R. , Santos S. C. , Silva‐Pereira I. , Silva M. A. S. , Silveira E. , Simões I. C. , Soares R. B. A. , Souza D. P. , De‐Souza M. T. , Andrade E. V. , Xavier M. A. S. , Veiga H. P. , Venancio E. J. , Carvalho M. J. A. , Oliveira A. G. , Inoue M. K. , Almeida N. F. , Walter M. E. M. T. , Soares C. M. A. , Brígido M. M. 
Published: January 2003

AbstractParacoccidioides brasiliensis is a pathogenic fungus that undergoes a temperature‐dependent cell morphology change from mycelium (22° C) to yeast (36° C). It is assumed that this morphological transition correlates with the infection of the human host. Our goal was to identify genes expressed in the mycelium (M) and yeast (Y) forms by EST sequencing in order to generate a partial map of the fungus transcriptome. Individual EST sequences were clustered by the CAP3 program and annotated using Blastx similarity analysis and InterPro Scan. Three different databases, GenBank nr, COG (clusters of orthologous groups) and GO (gene ontology) were used for annotation. A total of 3938 (Y = 1654 and M = 2274) ESTs were sequenced and clustered into 597 contigs and 1563 singlets, making up a total of 2160 genes, which possibly represent one‐quarter of the complete gene repertoire in P. brasiliensis. From this total, 1040 were successfully annotated and 894 could be classified in 18 functional COG categories as follows: cellular metabolism (44%); information storage and processing (25%); cellular processes—cell division, posttranslational modifications, among others (19%); and genes of unknown functions (12%). Computer analysis enabled us to identify some genes potentially involved in the dimorphic transition and drug resistance. Furthermore, computer subtraction analysis revealed several genes possibly expressed in stage‐specific forms of P. brasiliensis. Further analysis of these genes may provide new insights into the pathology and differentiation of P. brasiliensis. All EST sequences have been deposited in GenBank under Accession Nos CA580326–CA584263. Copyright © 2003 John Wiley & Sons, Ltd.
Escaping or connecting? Characteristics of youth who form close online relationships
Authors: Wolak Janis , Mitchell Kimberly J , Finkelhor David 
Published: January 2003

AbstractWe used data from a US national sample of Internet users, ages 10–17 (N=1501), to explore the characteristics of youth who had formed close relationships with people they met on the Internet (n=210). Girls who had high levels of conflict with parents or were highly troubled were more likely than other girls to have close online relationships, as were boys who had low levels of communication with parents or were highly troubled, compared to other boys. Age, race and aspects of Internet use were also related. We know little about the nature or quality of the close online relationships, but youth with these sorts of problems may be more vulnerable to online exploitation and to other possible ill effects of online relationships. At the same time, these relationships may have helpful aspects.
Illicit drug use, cigarette smoking and alcohol drinking behaviour among a sample of high school adolescents in the Pietersburg area of the Northern Province, South Africa
Authors: Madu Sylvester Ntomchukwu , Matla Ma‐Queen Patience 
Published: January 2003

AbstractAimThe aim of this study was to investigate the prevalence of illicit drug use, cigarette smoking and alcohol drinking behaviour among a sample of high‐school adolescents in the Pietersburg area (Central Region) of the Northern Province, South Africa.ParticipantsParticipants in this study were 435 secondary‐school adolescent students around the Pietersburg area (Central Region), in the Northern Province. Two hundred and forty‐three (56%) participants were female and 192 (44%) were male. They were aged between 15 and 19 years, with the mean age of 17.25 years (s.d.=1.34). Their educational level ranged between standards 7 and 10 (Grades 9–12).InstrumentsParticipants’ demographic variables were determined by use of a questionnaire which covered participants personal characteristics such as age and gender, as well as educational level. Illicit drug use, cigarette smoking, and alcohol drinking behaviour were also measured using the questionnaire.ResultsFindings of this study indicate the prevalence rate of 19.8% for illicit drug use, 10.6% for cigarette smoking and 39.1% for alcohol consumption among the participants. Both drug use, cigarette smoking and alcohol consumption are associated more with males than with females. The majority of the drug users and cigarette smokers indicated that they do so when they are bored, tired or stressed up, or at parties; and most of those who drink alcohol indicated that they do so at parties, weekends, or any other time. The mean age for first drug use is 14.9 years (s.d.=1.77); 14.54 years (s.d.=1.80) for first cigarette smoking and 15.33 years (s.d.=1.91) for first alcohol consumption. Among those who drink alcohol, 24.1% and 14.1% experience unplanned drunkenness and irritability, respectively. Unplanned drunkenness is associated with males, while unplanned irritability (after drinking alcohol) is not associated with any gender.ConclusionMental health workers and the law‐enforcement agencies should take note of the above findings while planning preventive and therapeutic strategies for the reduction of drug use, cigarette smoking and alcohol use and abuse among adolescents in the area.
Antiepileptic drugs in schizophrenia: a review
Authors: Hosák L. , Libiger J. 
Published: January 2003

SummaryThe first choice group of psychotropic agents in schizophrenia is neuroleptics. However, this treatment is not effective in all patients and with every symptom. We summarize papers published on the role of antiepileptic drugs in treatment-resistant schizophrenia. We have searched the computer database system MEDLINE for relevant articles including reviews, reports of drug studies and case histories. Antiepileptic drugs can change symptoms of schizophrenia by their action on GABA-ergic neurotransmission or via anti-glutamatergic mechanisms. High doses of adjunctive benzodiazepines reduce positive symptoms, anxiety, and agitation. Carbamazepine is effective in affective symptoms of schizophrenia and influences violent behavior in psychotic patients. Its anti-kindling action may represent a promising treatment strategy for some patients with chronic course of schizophrenia. Valproate treatment leads to a decrease in positive symptoms as well as hostility. Lamotrigine is expected to influence the positive, negative, affective, and cognitive symptoms of schizophrenia. New antiepileptics (e.g., gabapentin, oxcarbazepine, topiramate, vigabatrin) present a promise as potential adjuncts to neuroleptic treatment in resistant symptoms of schizophrenia.
Transmitral pulsed‐Doppler echocardiography is a more accurate technique compared with two‐dimensional echocardiography using dobutamine, in patients with one vessel coronary artery disease
Authors: Bajraktari Gani , Qirko Spiro , Fusco Rossana , Milazzo Angela , Xhaxho Brunilda , Pezzano Antonio 
Published: January 2003

AbstractTo examine the effects of dobutamine on pulsed‐Doppler left ventricular filling indices and its utility for evaluation of CAD we studied 14 patients with normal coronary arteries (Group 1) and 39 patients with significant CAD (>70% diameter stenosis). Patients with coronary artery disease (CAD) were divided into two groups: patients with one‐vessel coronary disease (Group 2); and those with multivessel CAD (Group 3). After stopping cardioactive treatment, patients underwent incremental dobutamine stress (5, 10, 20, 30 and 40 μg/kg/min) during pulsed‐Doppler interrogation of diastolic filling with simultaneous heart rate and blood pressure measurements. The following transmitral Doppler variables were measured at baseline and at peak‐dose of dobutamine: peak early (E) and peak atrial (A) velocity; E/A ratio; acceleration time (AT) and deceleration time (DT) of E wave; isovolumic relaxation time (IVRT); and time–velocity integral (TVI). Two‐dimensional echocardiography was performed to detect regional asinergy and analyzed using a 16 segment model. Results: Normals and CAD patients showed comparable changes in heart rate and blood pressure (P=NS between groups). Intergroup analysis of the changes of transmitral flow showed the significant changes for these indices (P<0.001): E velocity (−2.78±10.04, 12.4±9.4 and 16.47±10.65 cm/s); AT of E wave (1.66±2.47, −5.2±1.38 and −4.66±2.39 m/s2); DT of E wave (−0.23±0.18, 0.2±0.2 and 0.2±0.28 m/s2); and TVI of transmitral flow (−1.26±0.7, 3.5±1.75 and 4.1±1.66 cm), respectively for Groups 1, 2 and 3. All other transmitral Doppler variables showed insignificant changes (P=NS) to dobutamine between groups. It is important that the significance of these changes were the same for patients with one‐vessel and those with multivessel coronary disease. In conclusion, during dobutamine stress testing, patients with CAD, had an abnormal response of these transmitral Doppler indices: E wave; AT of E wave; DT of E wave; and the TVI of transmitral flow. The abnormal responses of these Doppler indices of left ventricular filling are more accurate markers of significant single vessel CAD than new wall motion abnormalities during conventional DSE.
Effect of early revascularisation in cardiogenic shock complicating acute myocardial infarction. A single center experience
Authors: Lindholm M.G. , Aldershvile J. , Sundgreen C. , Jørgensen Erik , Saunamäki Kari , Boesgaard S. 
Published: January 2003

AbstractBackground:Five to 10% of patients with acute myocardial infarction develop cardiogenic shock and the majority of these patients are expected to die within the first few weeks. In this study, we review our recent experience in the management of patients with cardiogenic shock complicating MI and examine the effect of early invasive revascularisation on mortality.Methods:Thirty‐six consecutive patients who developed cardiogenic shock less than 48 h after MI were retrospectively evaluated and divided into two treatment groups. One group received early invasive revascularisation (n=24) and the other group had no early invasive revascularisation, but received similar conventional intensive care medical treatment (n=12).Results:Baseline characteristics and hemodynamic variables were similar in both groups. Apart from invasive revascularisation and the use of intra aortic balloon counterpulsation (IABP), treatment strategies did not differ between the two groups. Thirty‐day mortality was 21% in the revascularised group of patients and 58% in the non‐revascularised group (P<0.05).Conclusions:Our data support previous observations suggesting that an aggressive treatment strategy including early invasive revascularisation and IABP is associated with improved short and long‐term survival in patients with cardiogenic shock. Since early revascularisation appears safe with a considerable treatment benefit, this approach must be considered in patients with short shock duration early after MI.