bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression patterns of basic helix‐loop‐helix transcription factors define subsets of olfactory progenitor cells
Authors: Manglapus Glen L. , Youngentob Steven L. , Schwob James E. 
Published: September 2004

AbstractDirect damage to the olfactory epithelium by inhalation of the olfactotoxin methyl bromide activates a population of multipotent globose basal cells, which reconstitute all depleted cell populations. Because members of the basic helix‐loop‐helix family of transcription factors are known to regulate neurogenesis and cell production, we performed in situ hybridization to examine the expression of several members of that family during the recovery of the rat olfactory epithelium after methyl bromide lesion. The numbers of basal cells expressing the proneural transcriptional activators Mash1, Neurogenin1, and NeuroD all fall precipitously 1 day after lesion. Mash1 levels begin to recover by 2 days, Neurogenin1 and NeuroD by 3 days, and substantial numbers of neurons reappear by 4 days. The antineurogenic factor Hes1 is limited to the sustentacular cells of the unlesioned olfactory epithelium and to the adjoining respiratory epithelium. Immediately after methyl bromide lesion, but not at any time after bulbectomy, a large fraction of residual, marker‐confirmed globose basal cells initiate expression of Hes1. Subsequently, the Hes1‐positive cells lose their association with the basal lamina, shift apically, and differentiate into sustentacular cells. In contrast, Hes5 is expressed by a small subset of globose basal cells and by olfactory ensheathing glia in the normal mucosa; Hes5 label disappears from both transiently after lesion. In sum, the recovery of the neuronal population after peripheral lesion recapitulates the sequence of transcription factor expression observed during embryonic development of the epithelium. Moreover, expression of Hes1 marks that population of globose basal cells committed to making sustentacular cells after methyl bromide lesion. J. Comp. Neurol. 479:216–233, 2004. © 2004 Wiley‐Liss, Inc.
Decomposition of images by the anisotropic Rudin‐Osher‐Fatemi model
Authors: Esedoḡlu Selim , Osher Stanley J. 
Published: September 2004

AbstractThe total‐variation‐based image denoising model of Rudin, Osher, and Fatemi can be generalized in a natural way to favor certain edge directions. We consider the resulting anisotropic energies and study properties of their minimizers. © 2004 Wiley Periodicals, Inc.
Metastases in the pancreas from nonhematologic neoplasms: Report of 20 cases evaluated by fine‐needle aspiration
Authors: Volmar Keith E. , Jones Claudia K. , Xie H. Bill 
Published: September 2004

AbstractWe reviewed fine‐needle aspiration (FNA) samples of metastatic tumor in the pancreas from nonhematologic neoplasms over a 5‐year period. In 1,050 total procedures, 20 metastases were diagnosed: 9 renal‐cell carcinomas (RCCs), 3 melanomas, 2 pulmonary small‐cell carcinomas, 2 breast carcinomas, 1 prostate carcinoma, 1 colon adenocarcinoma, 1 pulmonary squamous‐cell carcinoma, and 1 gastrointestinal stromal tumor. A wide range of latency from primary diagnosis was noted; the longest was RCC at 12.6 years (range, 5–28). Sites of involvement were: 13 heads, 4 bodies, and 3 tails. Eighteen cases presented as a solitary mass. The average size was 4.7 cm (range, 1.5–9.8), and a case of RCC (9.8 cm) was the largest. In seven cases, the clinical and radiographic impression was of a pancreatic primary. We conclude that metastases to the pancreas are rarely diagnosed by FNA and may clinically mimic a pancreatic primary. Diagn. Cytopathol. 2004;31:216–220. © 2004 Wiley‐Liss, Inc.
Cytological diagnosis of cystic brain tumors: A retrospective study of 88 cases
Authors: Hernandez Osvaldo , Zagzag David , Kelly Patrick , Golfinos John , Hummel Levine Pascale 
Published: September 2004

AbstractThe stereotaxic aspiration of cystic brain tumors is performed to provide cyst decompression and/or to facilitate surgical resection. The purpose of our study was to determine the diagnostic value of brain cyst fluid cytology, especially in clinically suspected recurrent tumors with no histological follow‐up (HF), when a diagnosis is most needed. We reviewed the cytological diagnoses of 88 aspirates from 70 patients with cystic brain tumors between 1995 and 2001, of which 31 had a prior known malignancy including 18 primary brain tumors (PBTs) and 13 adenocarcinomas (ACAs). Sixty‐nine of 88 aspirates were obtained intraoperatively. Nineteen of 88 aspirates were obtained from 10 patients with recurrent or persistent cystic brain tumors (8 patients with PBT and 2 patients with ACA), with available clinicoradiological correlation (magnetic resonance imaging/computed tomography [MRI/CT] scans) in 13 of them. The 88 aspirates were classified in three categories: 28 positive (32%), 15 atypical (17%), and 45 negative (51%). Eight of 28 positive cases (5 case of PBT, 2 cases of ACA, and 1 case of melanoma) were given a nonspecific diagnosis of malignant neoplasm (9% of all cases). Fifteen of 28 positive cases (6 cases of PBT, 8 cases of ACA, and 1 case of melanoma) were diagnosed correctly and confirmed by HF (17% of all cases). Four of 28 cases were ACA diagnosed solely by cytology (<4% of all cases). One neurocytoma (1/28) case was mistaken for an oligodendroglioma despite cell blocks (CBs) and immunophenotyping (IPT) (<1% of all cases). Eleven of 15 atypical cases were 8 cases of PBT, 2 cases of ACA, and 1 case of postoperative change (PC). Four of 15 atypical cases (from three patients with suspected PBT recurrence) could not be further characterized by CB/IPT and had no HF. Twenty‐seven of 45 negative cases were falsely negative (23 cases of PBT, 3 cases of ACA, and 1 case of malignant neoplasm); 11/45 cases were PC, and 7/45 (from five patients with clinically suspected tumor recurrence) cases had no HF. Cytological evaluation of brain cyst fluid is not a reliable means of diagnosing cystic brain neoplasms (including recurrences) due to a high false negative rate and a low sensitivity. Most of the negative or atypical cases (68% of all cases) were recurrent PBT of glial origin that may not be prone to exfoliate. These cytological specimens consisted of lysed blood, obscuring inflammatory cells, and degenerated diagnostic cells if any, yielding inconclusive results. Diagn. Cytopathol. 2004;31:221–228. © 2004 Wiley‐Liss, Inc.
A morphologic and statistical comparative study of small‐cell carcinoma and non‐Hodgkin's lymphoma in fine‐needle aspiration biopsy material from lymph nodes
Authors: De Las Casas Luis E. , Gokden Murat , Mukunyadzi Perkins , White Peter , Baker Sandra J. , Hermonat Paul L. , You Hong , Korourian Soheila , Malak Sharp F. , Miranda Roberto N. 
Published: September 2004

AbstractSmall‐cell carcinoma (SmC) and high‐grade non‐Hodgkin's lymphoma (NHL) are aggressive neoplasms that require prompt diagnosis and treatment. An immediate diagnosis can be obtained using fine‐needle aspiration biopsy (FNAB) material from lymph nodes (LNs), which are clinically or radiologically suspicious for tumor involvement. However, in aspirates from LNs, the cytologic distinction of SmC from NHL can be challenging. The purpose of this study was to evaluate the usefulness of various cytologic features that can be used during a rapid on‐site evaluation to differentiate these two entities. Twenty‐seven metastatic SmC and 50 NHLs cases diagnosed by FNAB of LNs were reviewed. All NHL diagnoses (neck, 29; abdomen, 9; axilla, 6; groin, 5; and parotid, 1) were confirmed with tissue sections, flow cytometry, or immunohistochemistry. These cases were classified as follicular, 21 (42%); diffuse large B cell, 13 (26%); small lymphocytic, 7 (14%); mantle cell, 4 (8%); anaplastic large cell, 2 (4%); and 1 each (2%), Burkitt, lymphoplasmacytic, and peripheral T‐cell lymphomas. Immunochemistry confirmed the cytologic diagnoses of all SmC cases (neck, 16; mediastinum, 9; abdomen, 1; and axilla, 1) with either positive chromogranin or synaptophysin. All specimens were reviewed independently by three cytopathologists who were unaware of the original diagnoses. The presence and proportion of single (noncohesive) tumor cells, lymphoglandular bodies, nuclear fragments, paranuclear blue inclusions, nuclear molding, evenly dispersed fine‐granular chromatin, crush artifact, and composition of cell clusters (monomorphic vs. polymorphic) were statistically evaluated. The presence of evenly dispersed fine‐granular chromatin, paranuclear blue inclusions, and nuclear fragments was each statistically significant in differentiating SmC when compared with NHL (P < 0.01). The remaining features were not significant in distinguishing SmC from NHL in LN aspirates. The identification of distinct cytologic findings such as evenly dispersed fine‐granular chromatin, paranuclear blue inclusions, and nuclear fragments can be a valuable aid to accurately diagnose and differentiate metastatic SmC from NHL in FNAB preparations from LNs. Diagn. Cytopathol. 2004;31:229–234. © 2004 Wiley‐Liss, Inc.
Immunocytochemical staining of p16INK4a protein from conventional Pap test and its association with human papillomavirus infection
Authors: Pientong Chamsai , Ekalaksananan Tipaya , Kongyingyoes Bunkerd , Kritpetcharat Onanong , Swadpanich Ussanee , Pengsa Prasit , Yuenyao Pissamai 
Published: September 2004

AbstractThe p16INK4a protein is immunocytochemically detected in liquid‐based (LB) specimens as a diagnostic marker of cervical dysplasia and neoplasia. Its up‐regulation is promoted by high‐risk human papillomavirus (HR‐HPV) infection. We aimed to detect p16INK4a on conventional Papanicolaou (Pap) test (CPT) slides and to determine the relationship between its overexpression and HR‐HPV infection. CPT and LB Pap test (LBPT) slides (165 samples of each) were examined by immunocytochemical staining for p16INK4a. After polymerase chain reaction (PCR), HPV‐DNA was genotyped by dot blot hybridization. The CPT slides displayed more numerous dispersed squamous cells and LBPT slides had a clearer background. Positive p16INK4a on CPT occurred in 0% (0/30), 52.5% (21/40), 54.3% (19/35), 100% (30/30), and 100% (30/30) in normal, atypical squamous cells of undetermined significance (ASCUS), low‐grade squamous intraepithelial lesions (LSILs), high‐grade SILs (HSILs), and squamous cell carcinomas (SCCs) cases, respectively. LBPT slides showed comparable results but were less sensitive. HPV‐DNA was detected in 86.7, 70, 45, 57.14, and 10% in SCCs, HSILs, ASCUS, LSILs, and normal cervical cells, respectively. Because HR‐HPV was identified in all HPV+ samples of high‐grade dysplasia (HSILs and SCCs) and all positive p16INK4a samples infected with HR‐HPV, the association of p16INK4a overexpression with HR‐HPV infection was confirmed. This study suggests that immunocytochemical staining of p16INK4a on CPT slides is convenient and cost‐effective for cervical cancer screening by the detection of dysplastic cells infected with HR‐HPV. Diagn. Cytopathol. 2004;31:235–242. © 2004 Wiley‐Liss, Inc.
Measurement and statistical analysis of spectrum occupancy
Authors: Fleurke S. R. , Dehling H. G. , Leonhard H. K. , Brinkerink A. D. , den Besten R. 
Published: September 2004

AbstractIn this paper, we discuss two definitions of spectrum occupancy in land‐mobile radiocommunication, actual occupancy and mean occupancy. We argue that for most monitoring purposes, the mean occupancy is the more relevant notion. We propose measurement procedures for spectrum occupancy, based on discrete observations of the channel, and investigate their properties. For the estimation of the mean occupancy, we provide confidence intervals, both for long as well as for short sampling intervals. For short sampling intervals, dependence of the observations is of crucial importance. We analyse the dependence for an alternating renewal model with Erlang(2)‐distributed renewals, which is better supported by the data than the exponential distribution used in past models. For the estimation of the actual spectrum occupancy, we propose a new random sampling scheme and investigate its properties. Copyright © 2004 AEI.
Iterative channel estimation and data detection in frequency‐selective fading MIMO channels
Authors: Lončar Maja , Müller Ralf R. , Wehinger Joachim , Mecklenbräuker Christoph F. , Abe Tetsushi 
Published: September 2004

AbstractSignals transmitted through multiple‐input multiple‐output (MIMO) wireless channels suffer from multiple‐access interference (MAI), multipath propagation and additive noise. Iterative multiuser receiver algorithms mitigate these signal impairments, while offering a good tradeoff between performance and complexity. The receiver presented in this paper performs channel estimation, multiuser detection and decoding in an iterative manner. The estimation of the frequency selective, block‐fading channel is initiated with the pilot symbols. In subsequent iterations, soft decisions of all the data symbols are used in an appropriate way to improve the channel estimates. This approach leads to significant improvement of the overall receiver performance, compared to other schemes. The bit‐error‐rate (BER) performance of the receiver is evaluated by simulations for different parameter setups. Copyright © 2004 AEI.
Generation of multiple Rayleigh fading sequences with specified cross‐correlations
Authors: Beaulieu Norman C. , Merani Maria Luisa 
Published: September 2004

AbstractA recent technique for generating two spatially correlated Rayleigh fading envelope sequences is generalized to give an efficient method for the generation of multiple correlated Rayleigh fading sequences. By coloring the quadrature components of the Rayleigh sequences, any desired envelope correlations can be realized for an arbitrary number of diversity branches. The computational complexity of the new method is compared to the computational complexity of a direct method. It is shown that properly utilizing the underlying block Toeplitz structure of the correlation matrix gives computational savings over the direct method. Copyright © 2004 AEI.
Trellis coded quantization/trellis coded continuous phase modulation over Rician channel with imperfect phase reference
Authors: Ucan Osman Nuri 
Published: September 2004

AbstractIn this paper, to improve bandwidth efficiency and error performance, trellis coded quantization/trellis continuous phase modulation (TCQ/TCPM) are combined and a trellis coded quantization/trellis coded continuous phase modulation (TCQ/TCCPM) scheme is introduced. Here, we use TCQ/TCM system as source coding because of its advantage over classical joint systems in terms of decoding time and complexity. We also present CPM for TCQ/TCM signals, since CPM provides low spectral occupancy and is suitable for power and bandwidth limited channels. The bit error performance of TCQ/TCCPM schemes is derived taking into account quantization noise over Rician channel with imperfect phase reference. The analytical upper bounds are obtained using Chernoff bounding technique, combined with the modified generating functional approach with no channel state information (CSI) and no side information for the phase noise process. As an example, TCQ/TCCPM scheme for 16CPFSK with modulation index h = 1/2 (16CPFSK‐TCQ/TCCPM) is investigated and compared to TCQ/TCM for 16PSK (16PSK‐TCQ/TCM). It is shown that 16CPFSK‐TCQ/TCCPM has better bit error performance than 16PSK‐TCQ/TCM in all signal‐to‐noise‐ratio (SNR) and quantization noise effect increases at high SNR values for both uniform and optimum quantization. Copyright © 2004 AEI.
Sequences and sequence pairs with imaginary correlation sidelobes
Authors: Lüke Hans Dieter , Hadinejad‐Mahram Hafez 
Published: September 2004

AbstractTime‐discrete signals with good correlation properties are used in various applications in communications engineering. In this paper, the construction of quadriphase and 8‐phase sequences and sequence pairs with purely imaginary aperiodic, periodic and odd‐periodic correlation sidelobes is discussed. Using coherent detection, these imaginary sequences show perfect correlation properties if only the real part of the correlation function is used. Copyright © 2004 AEI.
A new speech synthesis algorithm for high quality TTS systems: a mixed phase vocoder
Authors: Kwon Chul Hong , Lee Minkyu 
Published: September 2004

AbstractCurrently, time domain pitch synchronous overlap‐add (TD‐PSOLA) is the most popular synthesis algorithm for text‐to‐speech (TTS) systems. The algorithm produces very high quality synthetic speech, particularly when a pitch modification factor is small. However, as the pitch modification factor becomes larger, the quality degradation due to a slight pitch epoch detection error becomes severe. On the other hand, the vocoder framework has very flexible prosody manipulation. It can obtain a uniform voice quality over a wide range of prosody modification. Unfortunately, the synthesized speech quality from the vocoder is far from natural human speech, often showing buzzy quality. To remedy buzzy quality from the vocoder and make more natural synthetic speech, we propose a new speech synthesis algorithm for high quality TTS systems that is based on the homomorphic vocoder framework. The impulse response of vocal tract is obtained by mixing the minimum phase in lower frequency band and original phase in higher frequency band—thus, the name is a mixed phase vocoder. Informal subjective listening tests reveal that the mixed phase vocoder is a good candidate for TTS synthesis with high intelligibility and naturalness. Copyright © 2004 AEI.
Performance of affine geometry low‐density parity‐check codes in long‐haul optical communications
Authors: Djordjevic Ivan B. , Vasic Bane 
Published: September 2004

AbstractIn this paper, we investigate the performance of low‐density parity‐check (LDPC) codes in long‐haul optical communication systems for different modulation formats (nonreturn to zero (NRZ), return to zero (RZ), chirped return to zero (CRZ)). We are particularly concerned with high‐rate codes based on affine geometries. These codes have large minimum distance and simple iterative decoding algorithms, which make them good candidates for high‐speed applications such as optical communications. We consider both bit‐flipping iterative decoding and iterative decoding based on min‐sum algorithms. We demonstrate a significant performance improvement with respect to the state‐of‐the‐art error control schemes employed in long‐haul systems. Contrary to the common practice of considering the performance of error controlling schemes using the AWGN channel assumption, we consider the performance of the proposed LDPC schemes taking into account, in a natural way, all major impairments in long‐haul optical transmission such as ASE noise, pulse distortion due to fiber nonlinearities, chromatic dispersion or polarization dispersion, crosstalk effects, intersymbol‐interference (ISI), etc. Copyright © 2004 AEI.
Meshfree weak–strong (MWS) form method and its application to incompressible flow problems
Authors: Liu G. R. , Wu Y. L. , Ding H. 
Published: September 2004

AbstractA meshfree weak–strong (MWS) form method has been proposed by the authors' group for linear solid mechanics problems based on a combined weak and strong form of governing equations. This paper formulates the MWS method for the incompressible Navier–Stokes equations that is non‐linear in nature. In this method, the meshfree collocation method based on strong form equations is applied to the interior nodes and the nodes on the essential boundaries; the local Petrov–Galerkin weak form is applied only to the nodes on the natural boundaries of the problem domain. The MWS method is then applied to simulate the steady problem of natural convection in an enclosed domain and the unsteady problem of viscous flow around a circular cylinder using both regular and irregular nodal distributions. The simulation results are validated by comparing with those of other numerical methods as well as experimental data. It is demonstrated that the MWS method has very good efficiency and accuracy for fluid flow problems. It works perfectly well for irregular nodes using only local quadrature cells for nodes on the natural boundary, which can be generated without any difficulty. Copyright © 2004 John Wiley & Sons, Ltd.
Simulation of lid‐driven cavity flows by parallel lattice Boltzmann method using multi‐relaxation‐time scheme
Authors: Wu J.‐S. , Shao Y.‐L. 
Published: September 2004

AbstractTwo‐dimensional near‐incompressible steady lid‐driven cavity flows (Re = 100–7,500) are simulated using multi‐relaxation‐time (MRT) model in the parallel lattice Boltzmann BGK Bhatnager–Gross–Krook method (LBGK). Results are compared with those using single‐relaxation‐time (SRT) model in the LBGK method and previous simulation data using Navier–Stokes equations for the same flow conditions. Effects of variation of relaxation parameters in the MRT model, effects of number of the lattice points, improved computational convergence and reduced spatial oscillations of solution near geometrically singular points in the flow field using LBGK method due to MRT model are highlighted in the study. In summary, lattice Boltzmann method using MRT model introduces much less spatial oscillations near geometrical singular points, which is important for the successful simulation of higher Reynolds number flows. Copyright © 2004 John Wiley & Sons, Ltd.
Medical comorbidity in late‐life depression
Authors: Taylor Warren D. , McQuoid Douglas R. , Krishnan K. Ranga Rama 
Published: September 2004

AbstractObjectivesMedical comorbidity is common in elderly patients with depression, however the difference between depressed and non‐depressed elderly populations is not well established. Additionally, differences between subgroups of depressed populations, including those with MRI‐defined vascular depression and those with late‐onset compared with early‐onset depression are not well described.MethodsWe compared self‐report of medical disorders between 370 depressed elders and 157 non‐depressed control subjects. Subjects were additionally dichotomized based on presence or absence of subcortical MRI lesions and age of onset. Medical comorbidity was assessed by self report only, and depressed subjects were additionally assessed by the clinician‐rated Cumulative Illness Rating Scale.ResultsWhen compared with the non‐depressed group, depressed subjects were significantly more likely to report the presence of hypertension, heart disease, gastrointestinal ulcers, and ‘hardening of the arteries’. Analyses of subjects with subcortical disease demonstrated they were significantly older, more likely to have depression, and more likely to report the presence of hypertension. Finally, the depressed cohort with late‐onset depression (occurring after age 50 years) had more male subjects, exhibited greater CIRS scores, and greater prevalence of hypertension, but these did not reach a level of statistical significance after applying a Bonferroni correction.ConclusionsVascular comorbidities are common in depressed elders. The differences in the report of hypertension supports past work investigating a vascular contribution to late‐life depression. Given the association between depression and poor medical outcomes of cardiac disease, this population deserves clinical scrutiny and further research. Copyright © 2004 John Wiley & Sons, Ltd.