bluuebunny/crossref_metadata_2025 huggingface dataset:
The Accuracy of Owner‐Provided House Values: The 1978–1991 American Housing Survey
Authors: Kiel Katherine A. , Zabel Jeffrey E.
Published: September 2003

The American Housing Survey (AHS) includes the owner's valuation of the house as a measure of the house's value. If owner‐stated values are accurate, the AHS (as well as other survey instruments) can be used by researchers studying a variety of topics. In this study we use the metropolitan version of the AHS for three cities over fourteen years to compare owners' valuations with sales prices of houses that sold in the twelve months prior to an interview. We find that, on average, recent buyers report house values that are 8.4% higher than the stated sales prices. Further analysis indicates that these recent buyers, when compared with owners with longer tenure, overvalue their houses by 3.3%, on average. Thus, we find that the average owner overvalues his house by 5.1%. Also, differences between sales prices and owners' valuations are not related to particular characteristics of the house, occupants (other than length of tenure), or neighborhood. Thus, the use of the owners' valuations will result in accurate estimates of house price indexes and will provide reliable estimates of the prices of house and neighborhood characteristics.
Measuring Neighborhood Investments: An Examination of Community Choice
Authors: DiPasquale Denise , Kahn Matthew E.
Published: September 2003

Community choice is a very important household decision, since it represents an investment in community attributes that can have a significant effect on the quality of life of all household members, particularly by influencing the future prospects of children. In this paper, we examine the housing and community choices of migrants to and within Los Angeles County identified in the 1990 5% public‐use sample of the Census. Controlling for income, we find that expenditures on housing structure are quite similar across races. However, controlling for income, black and Hispanic households consume significantly less in community attributes than white households.
Valuing New Urbanism: The Case of Kentlands
Authors: Tu Charles C. , Eppli Mark J.
Published: September 2003

This study assesses the impact of new urbanism on single‐family home prices. Specifically, we use Duany and Plater‐Zyberk's traditional neighborhood development (TND) of Kentlands and surrounding conventional subdivisions to estimate the premium, if any, that single‐family homeowners are willing to pay to reside in a community with new urbanist features. Using data on 2,061 single‐family home transactions and several hedonic price models, the empirical evidence reveals that consumers are willing to pay a premium to locate in Kentlands.
Residential‐Mortgage Lending Discrimination and Lender‐Risk‐Compensating Policies
Authors: Buist Henry , Linneman Peter D. , Megbolugbe Isaac F.
Published: September 2003

The Boston Federal Reserve study (Munnell et al. 1996) concluded that illegal discrimination is a statistically significant contributor to the observed gap between white and minority residential‐mortgage rejection rates. The Boston study speculated that discrimination arises because lenders do not equally apply risk compensation or mitigation policies for imperfect loans. Using the same 1990 Boston loan application data, our study specifically examines the relation between compensating policies and discrimination. Since compensating policies are encouraged by secondary‐mortgage‐market sale guidelines, we model both the lender's origination decision and its loan sale decision. Using a rule‐based artificial‐intelligence technique applied to each lender, we infer compensating policies (rules) that equally apply to all races and explain lending decisions. A minority‐race indicator loses its statistical significance when an indicator of compensating‐policy violations appears in the loan accept–reject equation. This result reflects the fact that the risk levels of marginal minority loans tend to be more extreme than those of marginal white loans. However, the result does not necessarily reject the existence of discrimination. Equally applied policies may be empirically indistinguishable from unfairly applied policies. In addition, equally applied policies may fail the adverse‐impact doctrine if they do not serve a business necessity (such as profits). The industry's move away from discretionary, rule‐based decisions to mortgage scoring answers the need for a decision framework that rigorously uses loan performance to evaluate all loan applicants fairly.
Are Brokers' Commission Rates on Home Sales Too High? A Conceptual Analysis
Authors: Anglin Paul , Arnott Richard
Published: September 2003

Many people in North America believe that prevailing commission rates for residential real estate brokers are too high, even though such beliefs are not based on a formal model. This paper presents a general equilibrium model of the housing market in which real estate brokers serve as matching intermediaries. We use this model to construct an illustrative example which is calibrated using data consistent with a typical housing market. The example suggests that the commission rate which maximizes aggregate efficiency is considerably below the prevailing rate. Moreover, this finding appears to be robust to changes in the matching process.
Credit History and the FHA–Conventional Choice
Authors: Pennington‐Cross Anthony , Nichols Joseph
Published: September 2003

Models explaining whether households choose conventional or FHA mortgage financing typically use differential insurance premiums, loan‐to‐value (LTV) and payment‐to‐income underwriting standards, and local economic conditions to explain household behavior. Using a large and geographically diverse sample, we expand the standard choice model by including measures of borrower credit history. We find that the ability of a homebuyer to avoid credit problems is an important part of the FHA–conventional choice. In addition, credit scores of FHA borrowers are worse on average than those of conventional borrowers, but as LTV increases credit scores of conventional borrowers deteriorate.
Organizational Culture and Knowledge Management
Authors: Lim Thou Tin
Published: September 2003

As organizations in Singpore respond to the pressures of globalization, the adoption of knowledge management practices becomes more prevalent. In a hurry to implement this new business paradigm, organizations may have overlooked the influence of the cultural context which is commonly considered one of the pillars of knowledge management in a western-oriented organization.

This paper examines what was overlooked by Singapore organizations while moving towards knowledge management. Specifically, it studies the impact of organizational culture on knowledge management processes. A review of literature shows that there is a relationship between cultural factors and knowledge management processes. This relationship is reflected in a research model that helps to answer research questions and to formulate hypotheses for testing. The result indicates that knowledge management should consider not just the technological aspects of implementation but also the cultural, leadership and contextual aspects of an organization.
Cohomologically Kähler manifolds with no Kähler metrics
Authors: Fernández Marisa , Muñoz Vicente , Santisteban José A.
Published: September 2003

We show some examples of compact symplectic solvmanifolds, of
dimension greater than four, which are cohomologically
Kähler and do not admit Kähler metric since their
fundamental groups cannot be the fundamental group of any compact
Kähler manifold. Some of the examples that we study were
considered by Benson and Gordon (1990). However, whether such
manifolds have Kähler metrics was an open question. The
formality and the hard Lefschetz property are studied for the
symplectic submanifolds constructed by Auroux (1997) and some
consequences are discussed.
The Changing Character of Precipitation
Authors: Trenberth Kevin E. , Dai Aiguo , Rasmussen Roy M. , Parsons David B.
Published: September 2003

From a societal, weather, and climate perspective, precipitation intensity, duration, frequency, and phase are as much of concern as total amounts, as these factors determine the disposition of precipitation once it hits the ground and how much runs off. At the extremes of precipitation incidence are the events that give rise to floods and droughts, whose changes in occurrence and severity have an enormous impact on the environment and society. Hence, advancing understanding and the ability to model and predict the character of precipitation is vital but requires new approaches to examining data and models. Various mechanisms, storms and so forth, exist to bring about precipitation. Because the rate of precipitation, conditional on when it falls, greatly exceeds the rate of replenishment of moisture by surface evaporation, most precipitation comes from moisture already in the atmosphere at the time the storm begins, and transport of moisture by the storm-scale circulation into the storm is vital. Hence, the intensity of precipitation depends on available moisture, especially for heavy events. As climate warms, the amount of moisture in the atmosphere, which is governed by the Clausius–Clapeyron equation, is expected to rise much faster than the total precipitation amount, which is governed by the surface heat budget through evaporation. This implies that the main changes to be experienced are in the character of precipitation: increases in intensity must be offset by decreases in duration or frequency of events. The timing, duration, and intensity of precipitation can be systematically explored via the diurnal cycle, whose correct simulation in models remains an unsolved challenge of vital importance in global climate change. Typical problems include the premature initiation of convection, and precipitation events that are too light and too frequent. These challenges in observations, modeling, and understanding precipitation changes are being taken up in the NCAR “Water Cycle Across Scales” initiative, which will exploit the diurnal cycle as a test bed for a hierarchy of models to promote improvements in models.
Dynamic Stereochemistry of Alkyltris(9-triptycyl)stannanes
Authors: Yamamoto Gaku , Kaneko Megumi , Ohkuma Miki , Minoura Mao
Published: September 2003

1H dynamic NMR study of benzyltris(9-triptycyl)stannane (4) using two probes, the benzylic methylene and the aromatic peri-proton signals, revealed that the enantiomerization of the chiral conformers took place with ΔG‡ of 64.2 kJ mol−1 at 300 K.
Relationship between Molecular Skeleton and Stimulated-emission Threshold in Dilute Thin Films of Linear-chain-structured Fluorescent Dyes
Authors: Sakai Ken-ichi , Tsuzuki Takeo , Motoyoshiya Jiro , Inoue Masamitsu , Itoh Yoshihiro , Ichikawa Musubu , Fujimoto Tetsuya , Yamamoto Iwao , Koyama Toshiki , Taniguchi Yoshio
Published: September 2003

We carried out photopumping measurements for the dilute thin films of linear-chain-structured laser dyes where π-units such as benzene, ethylene, and oxazole are linearly linked via σ-bonds. Among them, 4-4′-bis[4-(di-p-tolylamino)styryl]biphenyl recorded the lowest stimulated-emission threshold of 2 μJ/cm2. It was revealed that the threshold was related to whether the number of constituent π-units was even or odd.
Structural modification of expandable polystyrene. I. Copolymerization with α‐methylstyrene
Authors: Taşkiran Isa , Sunal Gürkan , Erbay Erol , Uyanik Nurseli
Published: September 2003

Conventional expandable polystyrene (EPS) was modified by the preparation of copolymers containing 1.0, 2.5, and 5.0% α‐methylstyrene. Increasing the glass‐transition temperature of EPS was the aim of this work. Copolymeric expandable polystyrene (CEPS) samples were characterized with various techniques. 1H‐NMR spectroscopy was used for the determination of the composition, and gel permeation chromatography was used for the determination of the molecular weights and molecular weight distributions. Differential scanning calorimetry showed that the glass‐transition temperatures of the CEPS samples increased with increasing α‐methylstyrene contents. The prevention of the collapse of the EPS cells was observed in scanning electron microscopy images of the inner portions and outer surfaces of the CEPS samples. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 609–614, 2003
A study of dynamic vulcanization for polyamide‐12 and chlorobutyl rubber
Authors: Van Dyke J. D. (Jack) , Gnatowski Marek , Koutsandreas Andy , Burczyk Andrew
Published: September 2003

Polyamide‐12 and chlorobutyl rubber were blended by dynamic vulcanization in a high shear environment using curing systems based on sulfur, dithiocarbamate/ZnO, and 4,4‐methylenebiscyclohexylamine/MgO. As expected, all blends with curing agents show increased tensile strength and elongation at break in comparison to blends without curing agents. Maximum mechanical properties are obtained at relatively low levels of curing agent in all systems. Hexane extraction of the mixtures and measurement of percentage of insolubles along with the swelling index of the rubber phase confirm that a high level of cure is achieved at low levels of curing agent. Although the curatives are designed for the rubber phase, differential scanning calorimetry results indicate that both phases are affected during the dynamic vulcanization process, with polyamide‐12 showing a reduced melting temperature that is indicative of molecular weight reduction, structure changes, or reaction with the rubber phase. Scanning electron microscopy results indicate that phase size is reduced with increased blending time and level of curing agent. Rheological studies indicate that blends containing curing agents exhibit non‐Newtonian behavior to a greater extent than polyamide or nonvulcanized polyamide/chlorobutyl rubber blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 871–880, 2003
In vivo analysis of the apoptosis‐inducing effect of anti–endothelial cell antibodies in systemic sclerosis by the chorionallantoic membrane assay
Authors: Worda Miriam , Sgonc Roswitha , Dietrich Hermann , Niederegger Harald , Sundick Roy S. , Gershwin M. Eric , Wick Georg
Published: September 2003

Objective

Systemic sclerosis (SSc) is a connective tissue disease of unknown etiology characterized by mononuclear cell infiltration and fibrosis. Vascular injury occurs early in the course of disease, and previous in vitro studies suggest a primary role for anti–endothelial cell antibodies (AECAs) in mediating endothelial cell apoptosis. The aim of the present study was to analyze the apoptosis‐inducing effect of AECAs in vivo.

Methods

The optimum animal model for transfer experiments was the University of California at Davis line 200 (UCD‐200) chickens that spontaneously develop a hereditary disease with features closely resembling those of scleroderma in humans. AECA‐positive serum samples from UCD‐200 chickens were used for intravenous injection into normal CC chicken embryos on embryonic day (ED) 13 as well as for application onto chorionallantoic membranes (CAMs) of healthy control lines on ED 10. CAMs of ED 16 embryos and combs of 1‐week‐old CC chickens that had received the injected serum samples were analyzed for apoptotic endothelial cells by TUNEL.

Results

Staining of frozen CAM sections by immunofluorescence showed evidence of in vivo binding of AECAs to the microvascular endothelium. In most groups, transfer of AECA‐positive sera resulted in a significant increase in endothelial cell apoptosis as compared with controls.

Conclusion

This study is the first to demonstrate the in vivo apoptosis‐inducing effects of AECAs. The findings support our hypothesis of a primary pathogenetic role of AECAs in SSc.
Tie2 receptor tyrosine kinase, a major mediator of tumor necrosis factor α–induced angiogenesis in rheumatoid arthritis
Authors: DeBusk Laura M. , Chen Ying , Nishishita Toshihide , Chen Jin , Thomas James W. , Lin Pengnain Charles
Published: September 2003

Objective

Rheumatoid arthritis (RA) is an inflammatory disease and an angiogenic disease. However, the molecular mechanisms promoting angiogenesis in RA are not clearly identified. Our objective was to study the role of an endothelium‐specific receptor tyrosine kinase, Tie2, in angiogenesis of inflammatory arthritis.

Methods

Expression of Tie2 and its ligand, angiopoietin 1 (Ang1), in human synovium was examined by immunohistochemistry and Western blot. A novel synovium vascular window model was established to study the role of Tie2 in angiogenesis in vivo. Primary cultured endothelial cells and synoviocytes were used to study tumor necrosis factor α (TNFα)–induced Tie2 and Ang1 expression.

Results

Tie2 was implicated in pathologic angiogenesis. We observed that Tie2 and Ang1 were elevated in human RA synovium. Using a novel collagen‐induced arthritis synovial window model, we demonstrated that Tie2 signaling regulated arthritis angiogenesis in vivo. We also showed that Tie2 mediated TNFα‐induced angiogenesis in a mouse cornea assay. In addition, we observed that TNFα can regulate Tie2 activation in multiple ways that may involve interactions between endothelial cells and synoviocytes. TNFα up‐regulates Tie2 in endothelial cells through nuclear factor κB, and it up‐regulates Ang1 in synoviocytes. These findings suggest paracrine regulation of angiogenesis between endothelial cells and synoviocytes.

Conclusion

This study demonstrates that Tie2 regulates angiogenesis in inflammatory synovium. Tie2 signaling is an important angiogenic mediator that links the proinflammatory cytokine TNFα to pathologic angiogenesis.
Suppression of arthritic bone destruction by adenovirus‐mediated dominant‐negative Ras gene transfer to synoviocytes and osteoclasts
Authors: Yamamoto Aiichiro , Fukuda Akira , Seto Hiroaki , Miyazaki Tsuyoshi , Kadono Yuho , Sawada Yasuhiro , Nakamura Ichiro , Katagiri Hideki , Asano Tomoichiro , Tanaka Yoshiya , Oda Hiromi , Nakamura Kozo , Tanaka Sakae
Published: September 2003

Objective

To determine the role of Ras‐mediated signaling pathways in synovial cell activation and bone destruction in arthritic joints.

Methods

The E11 rheumatoid synovial cell line and primary synovial fibroblast‐like cells (SFCs) from patients with rheumatoid arthritis (RA) were gene‐transferred by replication‐deficient adenovirus vector carrying the dominant‐negative mutant of the ras gene (AxRasDN). The effects of RasDN overexpression on cellular proliferation, interleukin‐1 (IL‐1)–induced activation of mitogen‐activated protein kinases (extracellular signal–regulated kinase [ERK], p38, c‐Jun N‐terminal kinase [JNK]), and IL‐6 production by synovial cells were analyzed. The in vivo effects of Ras inhibition on synovial cell activation and arthritic bone destruction were analyzed by injection of AxRasDN into ankle joints of rats with adjuvant arthritis.

Results

AxRasDN markedly reduced the proliferation of RA SFCs. IL‐1, a proinflammatory cytokine involved in RA pathology, induced activation of ERK, p38, and JNK in the cells. Adenovirus vector–mediated RasDN overexpression suppressed ERK activation, but not p38 or JNK activation, in SFCs. IL‐6 is also an important proinflammatory cytokine, and RasDN inhibited IL‐1–induced production of IL‐6 by RA SFCs at both the transcriptional and protein levels. Injection of AxRasDN into ankle joints of rats with adjuvant arthritis ameliorated inflammation and suppressed bone destruction in the affected joints.

Conclusion

Ras‐mediated signaling pathways are involved in the activation of RA SFCs and the destruction of bone in arthritic joints, suggesting that inhibition of Ras signaling can be a novel approach for RA treatment that targets both synovial cell activation and bone destruction in the RA joint.
Aspiration cytology diagnosis of a primary amyloid tumor of thoracic vertebra: A case report
Authors: Manucha Varsha , Arora Vinod K. , Singh Navjeevan , Bhatia Arati
Published: September 2003

Isolated primary amyloid tumor of bone is rare; however, preoperative diagnosis can be rewarding because the prognosis is excellent. There are no clinical or roentgenographic criteria that can establish this diagnosis. There are few previous reports of fine‐needle aspiration (FNA) where diagnosis of amyloidoma was made retrospectively. They describe the presence of extracellular hyaline material along with plasma cells and lymphocytes. A 35‐year‐old female was referred to the FNA clinic with swelling in the right upper chest wall. Radiologic findings revealed a destructive lytic lesion involving the bodies of D1 and D2 vertebrae with extension into surrounding soft tissue. Repeated FNA smears were hypocellular but had abundant homogeneous flocculent material, which stained positive with Congo red. A few plasma cells and foreign‐body giant cells were also seen. We conclude that preoperative FNA cytology diagnosis of amyloid tumor is possible. Hypocellular smears with flocculent material, plasma cells, and foreign‐body giant cells in absence of granulation tissue should suggest the diagnosis. Diagn. Cytopathol. 2003;29:160–162. © 2003 Wiley‐Liss, Inc.
Cytohistologic correlations in angiosarcoma including classic and epithelioid variants: Institut Curie's experience
Authors: Klijanienko Jerzy , Caillaud Jean‐Michel , Lagacé Réal , Vielh Philippe
Published: September 2003

To characterize the cytological features of angiosarcomas, we reviewed the fine‐needle aspiration material and corresponding histologic sections of 29 tumors in 23 patients. Histologically, 24 tumors were of the classic type, and 5 were epithelioid angiosarcomas. The original corresponding cytologic diagnoses were as follows: angiosarcoma, 17 cases; sarcoma not otherwise specified, 8 cases; and rhabdomyosarcoma, 1 case. Three samples were cell‐poor and were considered suspicious of malignancy. The review of cytology samples showed that smears were cell‐rich in 17 tumors and cell‐poor in 12 tumors. A hemorrhagic background was present in 9 cases. Tumor cells were polymorphous, including spindle‐shaped, round to oval, and polygonal epithelioid cells and giant cells in different proportions. Erythrophagocytosis was seen in 12 tumors. Smears of classic angiosarcomas were polymorphous and lacking specific characteristics, whereas smears of epithelioid tumors were morphologically similar and composed of round to oval and polygonal, epithelial cells frequently arranged in clusters, and showing erythrophagocytosis. The wide spectrum of cellular components of angiosarcomas accounts for the difficulty in establishing accurate tumor typing, particularly with cell‐poor samples and low‐grade classic angiosarcoma. Entities to consider in the differential diagnosis are carcinoma, epithelioid sarcoma, pleomorphic rhabdomyosarcoma, and malignant melanoma. Diagn. Cytopathol. 2003;29:140–145. © 2003 Wiley‐Liss, Inc.
Essential oils from three Myrcia species
Authors: Zoghbi Maria das Graças B. , Andrade Eloisa Helena A. , da Silva Milton Helio L , Carreira Léa Maria M. , Maia José Guilherme S.
Published: September 2003

The oils of three samples of the leaves and ﬁne stems of Myrcia bracteata, M. cuprea and M. sylvatica were obtained by hydrodistillation and analysed by GC–MS. The main compounds found in the oils of M. bracteata were (E)‐nerolidol (80.8%) for the sample B‐1; (E)‐β‐farnesene (33.9%) for the sample B‐2; and spathulenol (31.0%) for the sample B‐3. The oils of M. cuprea were dominated by myrcene (48.1%) and β‐caryophyllene (19.9%) in the sample C‐1; by β‐caryophyllene (39.1%), myrcene (19.2%) and α‐pinene (15.9%) in the sample C‐2; and by β‐caryophyllene (38.1%), germacrene D (21.8%) and germacrene B (19.5%) in the sample C‐3. The major constituents identiﬁed in the oils of M. sylvatica were selin‐11‐en‐4‐α‐ol (24.7%), caryophyllene oxide (16.6%) and spathulenol (13.8%) in the sample S‐1; by cis‐calamenene (30.1%) and spathulenol (18.7%) in the sample S‐2; and by spathulenol (40.2%) and β‐bisabolene (14.7%) in the sample S‐3. Copyright © 2003 John Wiley & Sons, Ltd.
Whole‐embryo culture of E5.5 mouse embryos: Development to the gastrulation stage
Authors: Miura Shigeto , Mishina Yuji
Published: September 2003

Summary: This study reports establishment of an in vitro culture system for E5.5 mouse embryos that supports development to the gastrulation stage and allows the use of experimental approaches to study gastrulation during mouse embryogenesis. Recent experiments suggest that the extraembryonic tissues may play a critical role for gastrulation from as early as E5.5. To apply whole embryo culture to E5.5 embryos and analyze gastrulation, it is essential to optimize the conditions so that most of the embryos develop to the gastrulation stage in culture. For this purpose, we established a protocol in which embryos were isolated using micromanipulator and cultured with 50–75% rat serum. Although cultured embryos tended to grow a larger extraembryonic portion, more than 80% of them developed the primitive streak and induce mesoderm, which corresponds to the mid‐streak stage. genesis 37:38–43, 2003. © 2003 Wiley‐Liss, Inc.
Ectodysplasin regulates pattern formation in the mammalian hair coat
Authors: Zhang Min , Brancaccio Anna , Weiner Lorin , Missero Caterina , Brissette Janice L.
Published: September 2003

Summary: In mammalian skin, hair follicles develop at regular intervals and with site‐specific morphologies. This process generates distinct patterns of hair, but the mechanisms that establish these patterns remain largely unknown. Here we present evidence of follicular patterning by ectodysplasin‐A1 (Eda‐A1), a signaling protein necessary for the proper development of hair and other appendages. In transgenic mice, Eda‐A1 was targeted to the epithelial compartment of the developing skin. At periodic locations, multiple hair follicles were induced side by side, without any interfollicular space. These follicles grew into the dermis as a fusion and subsequently branched to create discrete stalks and hair bulbs. Thus, at sites where interfollicular skin normally forms, hair follicles developed instead. This result shows that Eda‐A1 can regulate basic developmental decisions, as cells were switched from interfollicular to follicular fates. Given these effects, it is likely that Eda‐A1 is among the key regulators of pattern formation in the skin. genesis 37:30–37, 2003. © 2003 Wiley‐Liss, Inc.
Pharmacological sensitivity of ATP release triggered by photoliberation of inositol‐1,4,5‐trisphosphate and zero extracellular calcium in brain endothelial cells
Authors: Braet Katleen , Aspeslagh Sandrine , Vandamme Wouter , Willecke Klaus , Martin Patricia E. M. , Evans W. Howard , Leybaert Luc
Published: September 2003

Recently, ATP has gained much interest as an extracellular messenger involved in the communication of calcium signals between cells. The mechanism of ATP release is, however, still a matter of debate. In the present study we investigated the possible contribution of connexin hemichannels or ion channels in the release of ATP in GP8, a rat brain endothelial cell line. Release of ATP was triggered by photoactivation of InsP3 or by reducing the extracellular calcium concentration. Both trigger protocols induced ATP release significantly above baseline. InsP3‐triggered ATP release was completely blocked by α‐glycyrrhetinic acid (α‐GA), the connexin mimetic peptides gap 26 and 27, and the trivalent ions gadolinium and lanthanum. ATP release triggered by zero calcium was, in addition to these substances, also blocked by flufenamic acid (FFA), niflumic acid, and NPPB. Gap 27 selectively blocked zero calcium‐triggered ATP release in connexin‐43 transfected HeLa cells, while having no effect in wild‐type and connexin‐32 transfected cells. Of all the agents used, only α‐GA, FFA and NPPB significantly reduced gap junctional coupling. In conclusion, InsP3 and zero calcium‐triggered ATP release show major similarities but also some differences in their sensitivity to the agents applied. It is suggested that both stimuli trigger ATP release through the same mechanism, which is connexin‐dependent, permeable in both directions, potently blocked by connexin mimetic peptides, and consistent with the opening of connexin hemichannels.
J. Cell. Physiol. 197: 205–213, 2003© 2003 Wiley‐Liss, Inc.
The effect of varying spectral resolution on the quality of high spectral and spatial resolution magnetic resonance images of the breast
Authors: Medved Milica , Du Weiliang , Zamora Marta A. , Fan Xiaobing , Olopade Olufunmilayo I. , MacEneaney Peter M. , Newstead Gillian , Karczmar Gregory S.
Published: September 2003

Purpose

To evaluate the effect of varying spectral resolution on image quality of high spectral and spatial resolution (HiSS) images.

Materials and Methods

Eight women with suspicious breast lesions and six healthy volunteers were scanned using echo‐planar spectroscopic imaging (EPSI) at 1.5 Tesla with 0.75‐ to 1‐mm in‐plane resolution and 2.3‐ to 2.6‐Hz spectral resolution. Time domain data were truncated to obtain proton spectra in each voxel with varying (2.6–83.3 Hz) resolution. Images with intensity proportional to water signal peak heights were synthesized. Changes in water signal line shape following contrast injection were analyzed.

Results

Fat suppression is optimized at ∼10‐Hz spectral resolution and is significantly improved by removal of wings of the fat resonance. This was accomplished by subtracting a Lorentzian fit to the fat resonance from the proton spectrum. The water resonance is often inhomogeneously broadened, and very high spectral resolution is necessary to resolve individual components. High spectral resolution is required for optimal contrast in anatomic features with very high T2* (e.g., within a lesion) and for detection of often subtle effects of contrast agents on water signal line shape.

Conclusion

Despite a trade‐off between the spectral resolution and signal‐to‐noise ratio, it is beneficial to acquire data at the highest spectral resolution currently attainable at 1.5 Tesla. J. Magn. Reson. Imaging 2003;18:442–448. © 2003 Wiley‐Liss, Inc.
Dynamic MRI contrast enhancement of renal cortex: A functional assessment of renovascular disease in patients with renal artery stenosis
Authors: Gandy Stephen J. , Sudarshan Thiru A.P. , Sheppard Declan G. , Allan Lynsay C. , McLeay Trudy B. , Houston J. Graeme
Published: September 2003

Purpose

To evaluate differences in the magnitude and time course of renal cortical contrast uptake in patients with minimal, moderate, and severe renal artery stenosis (RAS) using contrast‐enhanced magnetic resonance renography (CE‐MRR).

Materials and Methods

CE‐MRR was performed on 56 patients with renovascular disease using a three‐dimensional volume interpolated breath‐hold examination (VIBE) perfusion sequence. After administration of 2 mL of contrast, nine sequential axial VIBE datasets were acquired: at baseline, 7, 14, 21, 45, 60, 120, 180, and 240 seconds. Aortic peak signal enhancement and cortical peak signal enhancement through the mid portion of each kidney was recorded, along with the time delay between each peak. Each renal artery was subsequently examined using three‐dimensional contrast‐enhanced MR angiography, and graded as being minimally (0%–30%), moderately (31%–70%), or severely (71%–100%) stenotic.

Results

When the data were subdivided by RAS category, the cortical to aortic peak enhancement ratio (CAPR) reduced with increasing RAS. Further, the cortical to aortic time delay (CATD) increased with increasing RAS. These measurements were statistically significant between patients with minimal and moderate RAS compared to severe RAS

Conclusion

CE‐MRR can assist in the differentiation of patients with minimal or moderate RAS from those with severe RAS. J. Magn. Reson. Imaging 2003;18:461–466. © 2003 Wiley‐Liss, Inc.
Ecological implications of Fulbe pastoralism in southwestern Nigeria
Authors: Omotayo Akin M.
Published: September 2003

The study used a combination of ethno‐social surveys and Geographical Information Systems (GIS) to assess 651 pastoral households and their land use under agropastoral production systems in Ogun State, Nigeria. Yields of arable crops on agropastoralists' fields were generally low. Livestock productivity was similar on all parameters to levels in comparable contexts elsewhere across the West African subregion, but generally below possible potentials and on‐farm research findings. Pastoral households' activities presently influence between 221 km2 and 523 km2 of land in Ogun State. Pastoral grazing orbits extended beyond administrative boundaries, causing potential conflicts between local crop farmers and agropatoralists. Much of the land‐cover has been altered considerably around the areas of pastoral household settlements compared with the situation 20 years ago. It was concluded that a form of intervention was needed that would guarantee sustainability of the land‐use system. Copyright © 2003 John Wiley & Sons, Ltd.
A rotating array of antennas for confocal microwave breast imaging
Authors: Hernández‐López M. A. , Quintillán‐González M. , González García S. , Rubio Bretones A. , Gómez Martín R.
Published: September 2003

A planar array of four resistively loaded bow‐tie antennas has been designed to detect and image early‐stage malignant breast tumors by applying microwave confocal techniques. The finite‐difference time‐domain (FDTD) method has been used to simulate the entire detection problem. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 307–311, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11199
Similar gene structure of two Sox9a genes and their expression patterns during gonadal differentiation in a teleost fish, rice field eel (Monopterus albus)
Authors: Zhou Rongjia , Liu Li , Guo Yiqing , Yu Hongshi , Cheng Hanhua , Huang Xiao , Tiersch Terrence R. , Berta Philippe
Published: September 2003

The Sox9 gene encodes a transcription factor that is critical for testis determination and chondrogenesis in vertebrates. Mutations in human SOX9 cause campomelic dysplasia, a dominant skeletal dysmorphology syndrome often associated with male to female sex reversal. Here we show that the Sox9a gene was duplicated during evolution of the rice field eel, Monopterus albus, a freshwater fish which undergoes natural sex reversal from female to male during its life, and has a haploid genome size (0.6–0.8 pg) that is among the smallest of the vertebrates. The duplicated copies of the gene (named Sox9al and Sox9a2) fit within the Sox9 clade of vertebrates, especially in the Sox9a subfamily, not in the Sox9b subfamily. They have similar structures as revealed by both genomic and cDNA analysis. Furthermore, both Sox9al and Sox9a2 are expressed in testis, ovary, and ovotestis; and specifically in the outer layer (mainly gonocytes) of gonadal epithelium with bipotential capacity to form testis or ovary, suggesting that they have similar roles in gonadal differentiation during sex reversal in this species. The closely related gene structure and expression patterns of the two sox9a genes in the rice field eel also suggest that they arose in recent gene duplication events during evolution of this fish lineage. Mol. Reprod. Dev. 66: 211–217, 2003. © 2003 Wiley‐Liss, Inc.
Hypoxanthine (HX) inhibition of in vitro meiotic resumption in goat oocytes
Authors: Ma Suofeng , Lan Guocheng , Miao Yiliang , Wang Ziyu , Chang Zhongle , Luo Mingjiu , Tan Jinghe
Published: September 2003

To improve in vitro maturation and to understand the mechanism for meiotic resumption of oocytes, meiotic progression, and its control by hypoxanthine (HX) were studied in goat oocytes. Ovaries were obtained from a local abattoir, and cumulus–oocyte complexes (COCs) and follicular fluid were collected from follicles of different surface diameters (SDs). The meiotic competence and progression of oocytes were observed, and the concentration of HX in the follicular fluid and culture media was measured by high‐performance liquid chromatography (HPLC). Full meiotic competence of goat oocytes was acquired in follicles of ≥1.5 mm in SD with 90% of the oocytes developing to metaphase II (MII) stage after 24 hr in culture. The HX concentration in follicular fluid decreased with follicle development, from the highest level of 1.16 mM in ≤0.5 mm follicles to the lowest level of 0.45 mM in ≥5 mm follicles. HX inhibited meiotic resumption of goat oocytes in a concentration‐related manner but this inhibitory effect declined gradually. When we renewed the medium at 4 hr of HX‐199 (TCM‐199 supplemented with 4 mM HX) culture, the percentage of oocytes with intact germinal vesicle (GV) did not increase but decreased significantly instead. HPLC measurement of HX in the HX‐199 culture drops indicated that the HX concentration declined from 0 hr to 4 hr of culture and after medium renewal at 4 hr of culture. By adding dibutyryl cAMP (db‐cAMP) at medium renewal, we found that db‐cAMP held up the decline of GV percentages. Together, these results were consistent with the possibility that the decline of HX inhibitory effect was not due to HX depletion but rather due to the negative feedback of the metabolites on its further uptake by oocytes. Goat oocytes were capable of normal nuclear maturation and activation after temporal arrest by HX, but prolonged exposure to HX induced spontaneous activation. Mol. Reprod. Dev. 66: 306–313, 2003. © 2003 Wiley‐Liss, Inc.
Identiﬁcation of major metabolites in Aloe littoralis by high‐performance liquid chromatography–nuclear magnetic resonance spectroscopy
Authors: Karagianis Gloria , Viljoen Alvaro , Waterman Peter G.
Published: September 2003

Examination of the leaf exudate of the South African species Aloe littoralis by reversed‐phase HPLC revealed the presence of two major metabolites. The identiﬁcation of the two compounds without isolation was attempted by HPLC‐NMR based on separation using a C18 column eluting with a deuterium oxide:acetonitrile solvent gradient and an inverse HPLC‐NMR probe. For each compound, one‐dimensional proton spectra, and two‐dimensional homonuclear COSY and TOCSY, and heteronuclear HSQC and HMBC, spectra were collected. On the basis of the data obtained, the metabolites were characterised as 10‐hydroxyaloin B and deacetyllittoraloin. Copyright © 2003 John Wiley & Sons, Ltd.
Archaeobotanic evidence of the preincaic Chiribaya culture. Determination of capsaicinoids in archaeological samples of Capsicum frutescens and votive foods
Authors: Flamini Guido , Morelli Ivano , Piacenza Luigi
Published: September 2003

The lack of Capsicum species or paprika (a basic ingredient of Peruvian foodstuff) in preincaic archaeological samples and votive foods, as evidenced by archaeobotanic studies, has stimulated the chemical analyses of these samples by HPLC methods. The results conﬁrmed the absence of capsaicinoids in these samples whereas they were detected in more ancient fossil fruit. Copyright © 2003 John Wiley & Sons, Ltd.
Triblock copolymers and pentablock terpolymers of n‐hexyl isocyanate with styrene and isoprene: Synthesis, characterization, and thermal properties
Authors: Vazaios Aggelos , Pitsikalis Marinos , Hadjichristidis Nikos
Published: September 2003

Triblock copolymers and pentablock terpolymers of n‐hexyl isocyanate (H), styrene (S), and isoprene (I) of the type HSH (six samples, Mn:49–163 K, weight % of H:5–59), HIH (two samples, Mn:75 and 83.4 K, weight % of H:16 and 40), HSISH (one sample, Mn:79.4 K, weight % of H:13), and HISIH (one sample, Mn:128 K, weight % of H:25) were synthesized by high‐vacuum techniques in tetrahydrofuran at −98 °C with the sodium naphthalene/sodium tetraphenylborate initiating system. All materials were characterized by size exclusion chromatography, membrane osmometry, and 1H NMR. The combined molecular characterization results revealed a high degree of molecular and compositional homogeneity. The thermal properties of the synthesized materials were examined by thermogravimetric analysis and differential scanning calorimetry. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3094–3102, 2003
Gene therapy of lung cancer
Authors: Daniel Jonathan C. , Smythe W. Roy
Published: September 2003

It is estimated that there will be 157,200 deaths from lung cancer in 2003. Current regimens of surgery, chemotherapy and radiation have not significantly changed overall 5‐year survival rates for this disease. Thanks to intensive molecular studies over the last three decades, new targets for treatment have been identified, including replacement of tumor suppressor genes, prevention of angiogenesis and tumor growth, and regulation of programmed cell death. Promising advances have been made but obstacles still abound before effective use of these strategies at the patient bedside can occur. One area of concentration lies in developing more accurate and complete delivery of the therapeutic constructs. In the evolution of gene therapy approaches, from beginning theory to translational research, investigators in thoracic malignancies have played a leading role, utilizing a number of methods and delivery vehicles. The objective of this review is to discuss some of the major molecular targets available for manipulation in lung cancer, describe vectors and techniques currently used by thoracic researchers to deliver therapy, and provide the p53 model as an example of progression from bench research to clinical treatment. Semin. Surg. Oncol. 21:196–204, 2003. © 2003 Wiley‐Liss, Inc.
Characterization of Arabidopsis secretory phospholipase A2‐γ cDNA and its enzymatic properties1
Authors: Bahn Sung Chul , Lee Hyoung Yool , Kim Hae Jin , Ryu Stephen B. , Shin Jeong Sheop
Published: September 2003

Plant secretory phospholipases A2 (sPLA2s) probably play important roles in phospholipid signaling based on the data reported from other organisms, but their functions are poorly understood because of the lack of cloned sPLA2 genes. In this study, we cloned and characterized an Arabidopsis secretory phospholipase A2‐γ (AtsPLA2‐γ) cDNA, and examined its enzymatic properties. The recombinant protein of AtsPLA2‐γ showed maximal enzyme activity at pH 8.0, and required Ca2+ for activity. Moreover, AtsPLA2‐γ showed sn‐2 position specificity but no prominent acyl preference, though it showed head group specificity to phosphatidylethanolamine rather than to phosphatidylcholine. AtsPLA2‐γ was found to predominate in the mature flower rather than in other tissues, and subcellular localization analysis confirmed that AtsPLA2‐γ is secreted into the intercellular space.
The ubiquitin‐like domain of Herp is involved in Herp degradation, but not necessary for its enhancement of amyloid β‐protein generation
Authors: Sai Xiaorei , Kokame Koichi , Shiraishi Hirohisa , Kawamura Yuuki , Miyata Toshiyuki , Yanagisawa Katsuhiko , Komano Hiroto
Published: September 2003

Herp is an endoplasmic reticulum (ER)‐stress‐inducible membrane protein, which has a ubiquitin‐like domain (ULD). However, its biological function is as yet unknown. Previously, we reported that a high expression level of Herp in cells increases the generation of amyloid β‐protein (Aβ) and that Herp interacts with presenilin (PS). Here, we addressed the role of the ULD of Herp in Aβ generation and intracellular Herp stability. We found that the ULD is not essential for the enhancement of Aβ generation by Herp expression and the interaction of Herp with PS, but is involved in the rapid degradation of Herp, most likely via the ubiquitin/proteasome pathway. Thus, the ULD of Herp most likely plays a role in the regulation of the intracellular level of Herp under ER stress.
Human immunodeficiency virus‐1 Tat protein interacts with distinct proteasomal α and β subunits
Authors: Apcher G.Sébastien , Heink Sylvia , Zantopf Daniela , Kloetzel Peter-M. , Schmid Hans-P. , Mayer R.John , Krüger Elke
Published: September 2003

The human immunodeficiency virus‐1 (HIV‐1) Tat protein was previously reported to compete the association of PA28 regulator with the α rings of the 20S proteasome and to inhibit its peptidase activity. However, the distinct interaction sites within the proteasome complex remained to be determined. Here we show that HIV‐1 Tat binds to α4 and α7, six β subunits of the constitutive 20S proteasome and the interferon‐γ‐inducible subunits β2i and β5i. A Tat–proteasome interaction can also be demonstrated in vivo and leads to inhibition of proteasomal activity. This indicates that Tat can modulate or interfere with cellular proteasome function by specific interaction with distinct proteasomal subunits.
Effect of track spacing and data interpolation on the interpretation of benthic community distributions derived from RoxAnn™ acoustic surveys
Authors: Pinn Eunice H , Robertson M.R
Published: September 2003

A 150 mile2 (388 km2) area in the South Minch on the Scottish west coast was surveyed acoustically using the seabed discrimination system RoxAnn™. This site was chosen from BGS seabed sediment maps because of the wide variety of substratum types present within a relatively small area. The work presented here investigates different combinations of survey track spacing in relation to interpolation of acoustic data for mapping benthic biodiversity. Three different survey track spacings (4, 2 and 1 km) and three pixel sizes (1000, 500 and 250 m) were utilised. The results indicated considerable variations in the fine scale variations of the substratum maps produced and their accuracy in relation to ground truth data. Depending on the track spacing and level of interpolation utilised, the survey site could be considered relatively important under the UK Biodiversity Action Plan in terms of priority habitat types present or completely insignificant. These variations have serious implications for the use of this technology in site identification, conservation and management.
EXPERIENCES OF THE DEAF IN EARLY MODERN ENGLAND
Authors: COCKAYNE EMILY
Published: September 2003

Some recent studies have highlighted the importance of sounds for social interaction in the early modern period, yet the consequences for deaf members of society are rarely questioned. Those without the ability to hear lived in a world of sounds controlled by those who heard. This article explores the extent to which the deaf were socially integrated in English society between the mid-sixteenth and mid-eighteenth centuries. It also assesses the disadvantages suffered by those born deaf, or who lost their hearing. Crucial to the discussion is an understanding that experiences were not uniform, as the term deafness covered a wide spectrum of conditions, from temporary hearing loss to profound congenital deafness. Clearly some were more disabled than others, but their disadvantages were more to do with traditional social divisions of wealth and status, rather than the extent of their hearing impairment. Fundamentally, the most inhibiting factor was an inability to apprehend words.