bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrated video and voice transmission using packet reservation multiple access
Authors: Yeh Sheng‐Cheng , Wu Jung‐Shyr , Liang Yuan‐Cheng 
Published: August 2002

AbstractThis paper proposes a new protocol for the integration of voice and video transmission over the packet reservation multiple access (PRMA) system that is a modification of reservation‐ALOHA protocol. We focus on low bit‐rate video applications like video conferencing and visual telephony for wireless communications. The ITU–T H.263 standard provides a solution to the need for low bit‐rate video compression under 64 kbytes/s. The proposed protocol assumes that each voice terminal follows a traffic pattern of talk spurts and silent gaps with fixed permission probability (p=0.3), and each video terminal has the higher permission probability (p=1) to access the available slot based on ITU–T H.263 standard. Again, we present a ‘pseudo‐reservation’ scheme to release slots reserved by video terminals according to the contents of each video transmission buffer, and the active voice terminals can temporarily access the additional slots to improve the performance without sacrificing the video capacity of the system. The packet dropping probability of the active voice terminals and bandwidth utilization of the system are superior to the original PRMA, as indicated in simulation results. Copyright © 2001 John Wiley & Sons, Ltd.
ATM‐based wireless broadband access in the local loop
Authors: Eichinger Josef , Möhrmann Karl Heinz , Sommer Jörg , Zirwas Wolfgang , Plattner Alfred , Willke Stefan 
Published: August 2002

AbstractBroadband networks using wireless transmission techniques are a quick and flexible means of implementing subscriber access. Unoccupied frequency bands with sufficient bandwidth to allow the transmission of digital signals at very high bit rates are found only in the microwave bands. Because the path loss is fairly high at these frequencies, the diameter of radio cells is limited to a maximum of a few kilometres. This results in a microcellular system, which is best implemented in the form of a point‐to‐multipoint system, where one radio‐base station serves all subscribers registered in that radio cell. An interactive, broadband, ATM‐based radio local loop has undergone successful trials in Munich. Copyright © 2001 John Wiley & Sons, Ltd.
A WDM control architecture and destination conflicts analysis
Authors: Pountourakis Ioannis E. , Stavdas A. 
Published: August 2002

AbstractThe well‐known Single‐hop Wavelength division multiplexing (WDM) networks using passive star topology, provide direct connection between the source and the destination of a data packet but require some pretransmission coordination between the stations over a control channel. Since the electronic processing bottleneck that the single control channel architecture introduces is high, we propose a new WDM control architecture to overcome this problem. Also, we develop and analyse a queueing model of the network in order to obtain the queue length distribution and loss probabilities at the receiving sides of the stations. A rigourous method is developed to examine the receiver collision phenomenon and to evaluate the performance reduction due to the finite number of tuneable receivers at each station and finite population. Copyright © 2001 John Wiley & Sons, Ltd.
Fibre‐optic network architectures for on‐board digital avionics signal distribution
Authors: Alam Mohammad F. , Atiquzzaman Mohammed , Duncan Bradley D. , Nguyen Hung , Kunath Richard 
Published: August 2002

AbstractContinued progress in both civil and military radio‐frequency (RF) digital avionics applications is overstressing the capabilities and reliability of existing RF communication networks based on coaxial cables on board modern aircrafts. Future avionics systems will require high‐bandwidth on‐board communication links that are lightweight, immune to electromagnetic interference, and highly reliable. Fibre‐optic networks can meet all these challenges in a cost‐effective manner. Recently, on‐board fibre‐optic communication systems, where a fibre‐optic network acts like a local area network (LAN) for digital data communications, have become a topic of extensive research and development. However, modern digital avionics systems require a system capable of transporting microwave and millimeter‐wave RF signals that carry digital data on board an aircraft.Such optical networks transporting RF signals are completely different from the digital fibre‐optic communication systems.Recent advances in optoelectronics technology, including linear optoelectronic devices and wavelength division multiplexing (WDM), have opened a number of possibilities for designing on‐board fibre‐optic networks, including all‐optical networks for digital avionics RF signal communication. Theobjectiveof this paper is to present a number of optical network architectures for transmitting RF signals carrying digital data in an aircraft.In this paper,we investigate a number of different approaches, including all optical architectures, for building an optical network using fibre‐optic transmission of on‐board VHF and UHF RF signals. The relative merits and demerits of the network architectures are discussed, and the suitability of the architectures for particular applications is presented. Copyright © 2002 John Wiley & Sons, Ltd.
Using a multiple priority reservation MAC to support differentiated services over HFC systems
Authors: Angelopoulos J. D. , Leligou N. , Orphanoudakis Th. , Pikrammenos G. 
Published: August 2002

AbstractThe successful commercial deployment of Hybrid Fibre/Coaxial (HFC) access networks in the residential market has so far been driven by demand for faster Internet access and the prospects of a host of new services based on real‐time voice and video. To sustain their growth rates and compete with alternative approaches, such as ADSL, they must be enhanced with the capability to efficiently handle quality‐intensive real‐time services. The new multi‐service paradigm mandates isolation of traffic classes, conditioning of entering traffic and preventive control in addition to traditional closed‐loop control. The differentiated services (DiffServ) architecture with its relevant traffic control tools and the bundling of behaviour aggregates is particularly suited to the H/W‐based MAC of HFC systems. It constitutes a suitable framework enabling the support of proliferating real‐time voice‐ and video‐based services while aligning the system to the emerging Internet strategy of scalable service differentiation. The implementation of such a solution in the ACTS 327AROMA research project is presented in this paper. The performance of the system is evaluated using computer simulation. Copyright © 2002 John Wiley & Sons, Ltd.
Prevalence and epidemiologic correlates of atypical squamous cells of undetermined significance in women at low risk for cervical cancer
Authors: Becker Eduardo , Edelweiss Maria Isabel , Nonnenmacher Bernadete , Bozzetti Mary Clarisse 
Published: August 2002

AbstractOur aim was to determine the prevalence and epidemiologic correlates of atypical squamous cells of undetermined significance (ASCUS) in a population at low risk for cervical cancer in Porto Alegre, Brazil. Sociodemographic data and gynecological and obstetrical history from 977 women screened at an outpatient clinic were recorded. Specimens were collected for Papanicolaou cervical cytology, colposcopy, and biopsy (if indicated). Sixty‐two (6.3%) patients presented ASCUS, 21 (2.1%) presented low‐grade squamous intraepithelial lesions, and 6 (0.6%) presented high‐grade lesions. Presence of human papillomavirus (HPV) DNA in cervical cells (odds ratio (OR) = 1.57; confidence interval (CI) 95% = 1.11–2.23), history of HPV infection (OR = 3.12; CI 95% = 1.22–7.96), and becoming sexually active at 18 yr or younger (OR = 1.70; CI 95% = 1.15–2.51) were independently associated with ASCUS. ASCUS patients reported HPV infections and presented HPV DNA in cervical cells more often than did patients with normal cytology; therefore, they should be carefully monitored to ensure early detection of cancer precursor lesions and prevention of cervical cancer. Diagn. Cytopathol. 24:276–282, 2001. © 2001 Wiley‐Liss, Inc.
Comparison of antibodies to HBME‐1 and calretinin for the detection of mesothelial cells in effusion cytology
Authors: Fetsch Patricia A. , Simsir Aylin , Abati Andrea 
Published: August 2002

AbstractThe distinction of mesothelial cells in cytologic samples is often a diagnostic challenge. This is particularly true in potentially malignant effusions in which reactive mesothelial cells may simulate adenocarcinoma (ACA) cells, and in the differentiation of ACA vs. mesothelioma. We sought to determine the superior antibody for the positive identification of mesothelial cells in these circumstances.Cell block sections of 25 reactive and 8 malignant mesothelioma effusions were immunostained with an avidin‐biotin procedure, using antibodies to HBME‐1 and calretinin. No pretreatment of samples was necessary for the HBME‐1‐stained slides; microwave antigen retrieval was performed on all slides stained for calretinin. A negative control was performed on each sample. The staining intensity of tumor cells was scored on a scale of 0–3+, with the proportion of immunoreactive cells categorized as <25%, 25–50%, 50–75%, and >75%.The predominant staining pattern for HBME‐1 was surface, with rare samples also exhibiting cytoplasmic staining as well. The calretinin‐staining pattern was cytoplasmic, with peripheral condensation/prominence and accompanying nuclear staining. All samples were immunoreactive with both antibodies. Fifty‐five percent (18/33) of samples showed significantly stronger immunoreactivity with calretinin than with HBME‐1; 45% (15/33) of samples showed equivalent staining with the two markers. None of the samples in this study showed stronger immunoreactivity with HBME‐1 than with calretinin. Sixty‐one percent (20/33) of samples stained with HBME‐1 at a moderate (2+) intensity. Fifty‐five percent (18/33) of samples stained with calretinin at a strong (3+) intensity. While only 12% of samples showed >75% immunoreactivity for HBME‐1, 58% of samples showed >75% of cells immunoreactive for calretinin.Calretinin is the preferred marker in identifying mesothelial cells in cytologic samples, showing the highest sensitivity for mesothelial cells, as evidenced by a more intense staining reaction in a higher percentage of cells than with HBME‐1. Diagn. Cytopathol. 2001;25:158–161. Published 2001 Wiley‐Liss, Inc.
Solitary fibrous tumor: A study of cytologic features of six cases diagnosed by fine‐needle aspiration
Authors: Clayton Amy C. , Salomão Diva R. , Keeney Gary L. , Nascimento Antonio G. 
Published: August 2002

AbstractSolitary fibrous tumor (SFT) is a spindle‐cell neoplasm most often presenting as a pleural‐based tumor but increasingly recognized in other locations. Few reports have described the cytologic features of SFTs. Six cases of SFT diagnosed by fine‐needle aspiration (3 pleura, 2 retroperitoneum, and 1 orbit) were identified in the Mayo Clinic files. The smears (Papanicolaou‐stained) and corresponding histologic specimens were reviewed. Immunohistochemical staining for CD34 was performed in all cases. The cytologic findings were similar in all cases. The tumor cells were oval to polygonal, with cellularity ranging from scant to moderate. The background contained irregular ropy fragments of collagen and a few inflammatory cells. Most cells were dispersed singly, but all cases contained irregular, loose aggregates of cells enmeshed in a collagenous matrix. The nuclei were uniformly bland, with evenly distributed, finely granular chromatin. All cases were immunoreactive for CD34. SFT has distinctive cytologic features that allow diagnosis in cytologic specimens with the help of appropriate immunocytochemical stains on accompanying tissue biopsy specimens. Distinctive cytologic findings predictive of clinical behavior were not identified. Diagn. Cytopathol. 25:172–176, 2001. © 2001 Wiley‐Liss, Inc.
Dapsone analogs as potential polyamine binding site modulators of theN‐methyl‐D‐aspartate receptor complex
Authors: Bence Aimee K. , Rogers Dennis T. , Worthen David R. , Fu May , Littleton John M. , Crooks Peter A. 
Published: August 2002

AbstractA high‐throughput radioligand binding assay was used to screen a series of dapsone analogs for their capacity to displace [3H]‐spermidine and [3H]‐MK‐801 from their respective binding sites on theN‐methyl‐D‐aspartate (NMDA) receptor complex in rat brain homogenates. Dapsone did not alter [3H]‐spermidine or [3H]‐MK‐801 binding, suggesting that the neuroprotective properties that have been attributed to this compound may not be due to modulation of the NMDA receptor complex at the polyamine binding site. In contrast, structural analogs of dapsone, includingN‐phenyl‐1,4‐phenyldiamine and 4,4′diaminoazobenzene, effectively displaced [3H]‐SPD and [3H]‐MK‐801. These active dapsone analogs may represent a new class of polyamine binding site ligands that may provide opportunities for the rational design of novel NMDA receptor modulators. Drug Dev. Res. 51:268–272, 2000. © 2001 Wiley‐Liss, Inc.
Stability of coupled fluctuations in movement and visual attention in infants
Authors: Bacher L. F. , Robertson S. S. 
Published: August 2002

AbstractFluctuations in body movement and visual inspection were measured over minutes in 3‐month‐old infants to look for evidence of coupling. In Experiment 1, infants (n = 12) looked ad libitum at two identical pictures for an average of 7.3 min. Analysis of the spontaneous fluctuations in movement and inspection revealed that they were inversely coupled: Moment‐to‐moment changes in movement and inspection occurred in opposite directions. In Experiment 2, after 4 min of free looking, infants (n = 33) were presented with a new pair of stimuli, a temporary change in the stimuli, or no change in stimuli. The inverse coupling between the fluctuations in body movement and visual inspection found in Experiment 1 was present before and after the stimulus changes, even in infants whose body movement decreased transiently in response to the stimulus changes. The reappearance of inversely coupled fluctuations in body movement and visual inspection following the stimulus changes was led by increases in movement. The results demonstrate the stability of the inverse coupling between spontaneous fluctuations in body movement and visual inspection, and suggest that changes in movement may lead changes in inspection. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 99–106, 2001
Lack of association of insulin resistance and carotid intimal medial thickness in non‐diabetic Asian Indian subjects
Authors: Snehalatha C. , Vijay V. , Suresh Mohan R. , Satyavani K. , Sivasankari S. , Megha T. , Radhika S. , Ramachandran A. 
Published: August 2002

AbstractObjectiveAtherosclerosis is associated with insulin resistance (IR) and dyslipidaemia. Impaired glucose tolerance (IGT) is characterised by IR and is associated with a higher risk of atherosclerosis. The objective of the present study was to test whether early atherosclerosis indicated by intimal medial thickness (IMT) of common carotid artery (CCA) and internal carotid artery (ICA) is higher in IGT than in normoglycaemic subjects (NGT) and to look foran association of IMT with IR and dyslipidaemia.Study design and methodsNinety‐nine randomly selected non‐diabetic subjects aged ≥35 years (48 NGT and 51 IGT) were studied. Measurements of body mass index (BMI), waist/hip ratio (WHR), blood pressure, cholesterol‐total, HDL, LDL, VLDL, triglycerides (TG), lipoprotein (a), apolipoprotein‐A1 (Apo A1) and apolipoprotein‐B (Apo B) and ratio of Apo A1/Apo B were estimated. Insulin resistance (HOMA‐IR) was calculated using the fasting plasma insulin and glucose values. IMT of CCA and ICA were measured using high‐resolution β‐mode ultrasonography.ResultsSubjects with IGT and NGT were matched for BMI and WHR; HOMA‐IR was higher in IGT vs NGT (7.92±4.2 vs 6.07±3.76, p
=0.028). Age‐adjusted IMT values were similar in NGT and IGT (CCA 0.59±0.17 and 0.63±0.22 mm and ICA 0.44±0.10 and 0.45±0.10 mm, respectively). Further analyses were done in the total group. Multiple linear regression analyses showed that CCA‐IMT was significantly associated with age and negatively associated with Apo A1/Apo B ratio. ICA‐IMT was associated withage only. IMT was significantly correlated with cholesterol‐total and LDL‐cholesterol and apolipoproteins. It was not associated with IR.ConclusionIn southern Indians, IGT did not influence the IMT. Although insulin resistance was higher in IGT, it was not associated with higher IMT. Conventional risk factors such as cholesterol, LDL‐cholesterol and apolipoproteins showed association with IMT in the insulin‐resistant population. Copyright © 2001 John Wiley & Sons, Ltd.
Changes in endoneurial blood flow, motor nerve conduction velocity and vascular relaxation of epineurial arterioles of the sciatic nerve in ZDF‐obese diabetic rats
Authors: Coppey Lawrence J. , Gellett Jill S. , Davidson Eric P. , Dunlap Joyce A. , Yorek Mark A. 
Published: August 2002

AbstractBackgroundWe have previously reported that in streptozotocin‐induced diabetic rats, reduction in endoneurial blood flow (EBF) and impairment of acetylcholine‐mediated vascular relaxation of arterioles that provide circulation to the sciatic nerve precedes slowing of motor nerve conduction velocity (MNCV). However, in animal models of type 2 diabetes it is unknown whether slowing of MNCV is accompanied by vascular dysfunction.MethodsUsing ZDF‐lean and ZDF‐obese diabetic rats we examined whether diabetes‐induced slowing in MNCV was associated with a reduction in EBF and impaired vascular relaxation in epineurial arterioles of the sciatic nerve. We measured MNCV in the sciatic nerve using a non‐invasive procedure, and sciatic nerve nutritive blood flow using microelectrode polarography. In vitro videomicroscopy was employed to quantify arteriolar diameter responses to acetylcholine in arterioles overlying the sciatic nerve.ResultsMNCV and EBF in hyperglycemic (4‐week duration) ZDF‐obese diabetic rats were significantly decreased by 30% and 63%, respectively, compared to age‐matched ZDF‐lean rats. Acetylcholine elicited a dose‐dependent dilation of epineurial vessels from ZDF‐lean and ZDF‐obese diabetic rats, although acetylcholine‐induced dilation was significantly reduced in ZDF‐obese diabetic rats. Determination of markers of oxidative stress provided ambiguous results. Superoxide levels were increased in epineurial vessels from ZDF‐obese diabetic rats. Lens glutathione levels were decreased and serum thiobarbituric acid reactive substances increased in ZDF‐obese diabetic rats but sciatic nerve conjugated diene and glutathione levels were not significantly different compared to ZDF‐lean rats.ConclusionsDiabetes causes a reduction in EBF and impairment in vascular relaxation in epineurial vessels in ZDF‐obese diabetic rats. This impaired vascular response is associated with neural dysfunction. Copyright © 2002 John Wiley & Sons, Ltd.
Role for α6 integrin during lens development: Evidence for signaling through IGF‐1R and ERK
Authors: Walker Janice L. , Zhang Liping , Zhou Jian , Woolkalis Marilyn J. , Menko A. Sue 
Published: August 2002

AbstractWe show that α6 integrin function was required for normal lens cell differentiation by using an antisense construct to suppress α6 integrin expression. To elucidate the mechanism by which this integrin functions in the regulation of the lens cell differentiation process, we determined the molecular composition of α6 integrin signaling complexes at distinct stages of differentiation in vivo. Because both α6 integrin and insulin‐like growth factor‐1 (IGF‐1) have been implicated in signaling lens cell differentiation, we examined the possibility that they formed a signaling complex in the embryonic lens. Coprecipitation analysis revealed that α6 integrin/IGF‐1 receptor complexes were present and that their association was greatest in the equatorial zone, the region of the embryonic lens in which lens cells proliferate and then initiate their differentiation. These results provide in vivo support for the formation of integrin/growth factor receptor signaling complexes. We also found that extracellular signal‐regulated kinase (ERK), a downstream effector of both integrin and growth factor receptor signaling pathways, was associated with the α6 integrin signaling complexes in the embryonic lens. This result was supported by our findings that activated ERK, in addition to its nuclear location, localized to lens cell membranes in specific regions of cell‐matrix and cell–cell contact. A connection between integrin ligand engagement and ERK activation was shown in vitro after lens cell attachment to laminin. These results demonstrate that α6 integrin function is required for the early stages of lens cell differentiation most likely through its association with the IGF‐1 receptor and the activation of ERK. © 2002 Wiley‐Liss, Inc.
Receptor‐regulated and inhibitory Smads are critical in regulating transforming growth factorβ–mediated Meckel's cartilage development
Authors: Ito Yoshihiro , Bringas Pablo , Mogharei Ali , Zhao Jingsong , Deng Chuxia , Chai Yang 
Published: August 2002

AbstractThe proper development of Meckel's cartilage is critical for craniofacial skeletogenesis, because it serves as the primordium for the formation of mandible, malleus, incus, and sphenomandibular ligament. Cranial neural crest (CNC) cells contribute significantly to the formation of Meckel's cartilage. Members of the transforming growth factor beta (TGF‐β) family control the proliferation and differentiation of CNC cells during craniofacial skeletogenesis. TGF‐β signaling is transduced from the cell membrane to the nucleus by means of specific type I and type II receptors and phosphorylated Smad proteins. Here we demonstrate that application of TGF‐β promotes chondrogenesis by specifically increasing proliferation of CNC‐derived chondrocytes and production of extracellular matrix. To understand the molecular regulation of TGF‐β signaling, we have examined the biological function of both TGF‐β receptor‐regulated and inhibitory Smads during Meckel's cartilage development. The expression patterns of Smad2, 3, and 7 are identical to the ones of endogenous TGF‐β and its cognate receptors during Meckel's cartilage development, establishing the potential that these intracellular signaling Smads may regulate TGF‐β‐mediated chondrogenesis. Functional haploinsufficiency of Smad2 delays TGF‐β–mediated Meckel's cartilage development. Overproduction of Smad7 severely inhibits Meckel's cartilage formation, indicating a negative feedback on TGF‐β signaling by inhibitory Smad is critical in orchestrating TGF‐β–mediated gene regulation during embryonic chondrogenesis. The effectiveness of TGF‐β signaling is highly sensitive to the level of Smad gene expression. © 2002 Wiley‐Liss, Inc.