bluuebunny/crossref_metadata_2025 huggingface dataset:
Gene Transfer Strategies for the Physiologist
Authors: Wong Liang‐Fong , Wells Sara , Murphy David
Published: May 2004

Foreign genes can be introduced into whole animals using methods of germline transgenesis and somatic gene delivery. While germline transgenesis can generate useful animal models for genetic studies, it can be costly, time‐consuming and requires the use of a large number of animals. An alternative means of gene transfer is to deliver genes to somatic cells using non‐viral and viral technologies. Non‐viral methods such as naked DNA injection, electroporation and liposome/cation lipid‐mediated gene transfer are relatively inefficient. In contrast, viruses are effective vehicles that carry foreign genes into a cell rapidly and efficiently. Here we illustrate the usefulness of adenoviral vectors to express a potent and specific inhibitor of cAMP‐dependent protein kinase (PKA) to study the role of cyclic 3′,5′‐cyclic AMP (cAMP) in the osmotic regulation of the vasopressin gene in a transgenic rat model. The ability to modify endogenous systems within specific cells in a whole animal model allows gene effects to be studied with physiological relevance. The combination of molecular biology and integrative physiology is a powerful application that can aid in the elucidation of how gene function can translate into complex systems in an organism
Antisense Oligonucleotides in the Study of Central Mechanisms of the Cardiovascular Regulation
Authors: Culman Juraj
Published: May 2004

In the past several years, the progress in the development of molecular biology and the elucidation of gene sequences has created new approaches for studying biological functions and developing new diagnostic and therapeutic strategies. One of the most exciting advances has been the development of antisense technology, which represents a new strategy allowing modulation of protein synthesis with high specificity by preventing protein expression at the level of RNA or DNA. Many classical pharmacological approaches in neurobiological research are often based on the inhibition of biologically active proteins, such as receptors for neurotransmitters, or enzymes involved in neurotransmitter synthesis or degradation. The use of antisense oligodeoxynucleotides offers an alternative tool to manipulate selectively the expression of neurotransmitters or their receptors in neuronal tissue. This approach is especially useful when selective, high‐affinity antagonists are not available. As a result, this technology has gained acceptance in the study of cell signalling mechanisms and the molecular basis of neuronal function. This paper provides a brief background to the antisense technique and explores methodological aspects, particularly in the whole animal. The use of the antisense technology in studies focused on central mechanisms regulating the cardiovascular system is then discussed.
Somatic Gene Transfer: Implications for Cardiovascular Control
Authors: Kasparov S. , Paton J. F. R.
Published: May 2004

There is a great need for closer integration between physiologists and molecular biologists. These two research fields might soon form a single research discipline under the umbrella of molecular physiology. One of the areas where this interaction may be particularly fruitful is with somatic gene transfer using replication‐deficient viral vectors. We applied this approach to study the central control of the cardiovascular system at the level of the nucleus of the solitary tract (NTS). We assess critically this new methodology as applied to experiments in an integrative environment (such as the whole animal). The usefulness of in vivo gene transfer is illustrated by an experiment where viral gene delivery helped to circumvent the problem imposed by an absence of a specific pharmacological blocker of the enzyme, endothelial nitric oxide synthase (eNOS). The pros and cons of using adenoviral vectors as opposed to conventional pharmacological approaches are discussed. We conclude that the use of adenoviruses to manipulate genes offers a new avenue for physiologists studying neuronal mechanisms in integrative models.
Ethical consumerism: a view from Finland
Authors: Uusitalo Outi , Oksanen Reetta
Published: May 2004

Business ethics and corporate social responsibility have gained more attention in recent years. However, the consumers’ perspective on ethics is still a little researched area. This study reports a survey (n = 713) on the views of Finnish consumers about ethics in trade. Consumers’ willingness to promote business ethics as well as the obstacles to ethical consumption are investigated. The results of the study show that while the majority of the respondents regard business ethics as important, this attitude does not translate into their choice behaviour. Consumers are uncertain about which products and firms follow ethical rules and which do not. The most important obstacles to ethical consumption were difficulties in obtaining information, problems in product availability and high prices of ethical products.
Measuring physical access to ‘healthy foods’ in areas of social deprivation: a case study in Cardiff
Authors: Guy Clifford M. , David Gemma
Published: May 2004

This paper examines some characteristics of ‘food deserts’– areas of social deprivation which have poor physical access to food shopping – in a large British city, Cardiff. The stereotype of the ‘food desert’ is critically examined, emphasizing the importance attached by residents of such areas to easy access to food shopping, especially in multiple supermarkets. The case study of Cardiff briefly discusses the identification of potential ‘food deserts’, and then examines the structures of ‘healthy food’ availability and prices in four areas of the city (two in the inner city, two in the outer city) where physical access to large multiple supermarkets is poor. The analysis shows that the local shops in these areas cannot compete generally with large supermarkets on either availability of items or their prices, but that the local shops in the inner city areas are rather more competitive than those in the outer areas. Implications for research and policy formulation are finally discussed.
Food choice, nutrition education and parental influence on British and Korean primary school children
Authors: McCullough Fiona S.W. , Yoo Seunghee , Ainsworth Paul
Published: May 2004

The nutritional status of children can influence their health and the risk factors for developing chronic diseases later in life. Korea is unique in that it is relatively westernized and yet maintains much of the traditional foods and cooking methods. Effective nutrition education should help children to choose a healthy diet through the establishment of positive dietary practices and habits. The main purpose of this research is to compare awareness towards nutrition education between primary schools in the UK and Korea and nutritional knowledge that children and parents have in these countries. Dietary and healthy eating knowledge data were collected by a questionnaire as part of a case study comparison using one primary school in Manchester, UK, and one in Seoul, Korea. A total of 171 primary school children and 124 parents of the children were recruited. The results indicated that children and parents appeared to be aware of the importance of limiting fat, sodium and sugar intakes, and requiring non‐starch polysaccharide (NSP). However, in the case of some foods they did not have satisfactory nutritional knowledge of which foods were high in fat, salt, sugar and NSP. British children had a better understanding of the health implication of fat than Korean children, whereas more Korean children considered excessive salt intake harmful than British children. There seemed to be differences in dietary pattern and familiarity with food between the two countries. Children identified parents as the main source of nutritional information. Therefore, parents as well as children need to learn about nutrition in order to give appropriate information or advice to improve the diets of their children. Children preferred exciting, fun, positive and a practical approach to learning about nutrition, such as computer packages and cookery classes. Parents wanted schools to give their children more information about nutrition. This research has shown that nutrition education in schools should be concerned not only to provide nutritional knowledge but also to encourage children to choose healthy food by redesigning nutrition education and school meals.
The role of dietary information in women's whole milk and low‐fat milk intakes
Authors: Kim Sora , Douthitt Robin A.
Published: May 2004

This study examines the effects of dietary information on women's whole and low‐fat milk intakes. The sample is 1928 female meal planners aged 20 years or over who provided information on their milk intake for 2 days in the 1994–96 Continuing Survey of Food Intakes by Individuals and who completed the 1994–96 Diet and Health Knowledge Survey in the follow‐up interview. The nested Tobit model was used to handle the sequentially censored data. Women's dietary information contributed to reduced whole milk consumption and increased low‐fat milk consumption indicating different effects on whole milk and low‐fat milk consumption.
Product attributes and consumer acceptance of nutritionally enhanced genetically modified foods
Authors: Hossain Ferdaus , Onyango Benjamin
Published: May 2004

Using data from a national survey, this study analyses US consumers’ acceptance of genetically modified foods that provide additional nutritional benefits. Using an ordered probit model, this study examines the relation between the willingness to consume genetically modified foods and consumers’ economic, demographic and value attributes. Empirical results suggest that despite having some reservations, especially about the use of biotechnology in animals, American consumers are not decidedly opposed to food biotechnology. Consumers’ economic and demographic variables are only weakly related to their acceptance of food biotechnology, especially when technology involves plant‐to‐plant DNA transfer. However, public trust and confidence in various private and public institutions are significantly related to their acceptance of food biotechnology. Overall, consumer acceptance of bioengineered foods is driven primarily by public perceptions of risks, benefits and safety of these food products.
The ownership and use of small kitchen domestic appliances: case study, Liverpool
Authors: Efstathiou Aglaia , Grant Diane , Maxwell Sheila M.
Published: May 2004

The nutritional habits of UK consumers have become a cause for concern with an increasing number of people suffering from diseases related to nutrition. The way in which food is prepared may contribute to the nutritional content of the diet. Traditional methods of cooking and eating are being influenced by increased ownership of domestic appliances. This study aimed to carry out a cross sectional study of people living on Merseyside to determine the ownership and use of small kitchen domestic appliances in relation to the possible consequences the appliances may have on the nutrient intake of the individual. An opportunistic sample of 276 female adults aged 25–70 years was recruited from amongst university staff and community groups within Merseyside. Data were collected using a self‐completion questionnaire consisting of questions concerning personal details, the ownership and use of domestic appliances that may influence nutrient intake. The Liverpool John Moores University Ethics Committee granted ethical approval. Microwave ovens, electric toasters and grills were owned by 80% of the population. Coffee makers, handheld electric food mixers, sandwich makers, blenders and food processors although owned by over 45% were used by the majority only once a week or less. Newer items such as a bread maker were owned by 9% who were significantly more likely to have a professional occupation. Those with unskilled occupations were significantly more likely to own a deep fat fryer and least likely to own a food processor. Those aged 25–34 years were significantly least likely to own a handheld food mixer. Households comprised of couples with or without children were significantly more likely to own sandwich makers, bread makers, food processors and handheld food mixers. No difference in the use of the appliances was found with occupational group or age. A large percentage of people own a variety of domestic appliances, the use of which may have a beneficial effect on their nutrient intake, however, it is of concern that those in the lower socio‐economic group were more likely to own appliances that will have a negative effect on their diet.
Creating a satisfying internet shopping experience via atmospheric variables
Authors: McKinney Letecia N.
Published: May 2004

The purpose of this research was to identify the atmospheric variables that contributed to satisfaction for internet consumers with different orientations toward shopping. Atmospheric categories that were proposed for studying internet environments included external and internal variables, layout and design, point‐of‐purchase, and customer services. Some consumers had a convenience orientation toward shopping on the internet, while others were apprehensive, apathetic, and highly involved in internet shopping. A segment of internet consumers also exhibited positive orientations toward store shopping. Results showed that some atmospheric variables influenced satisfaction for all consumers, regardless of their shopping orientation; however, some variables were contributors of satisfaction for specific shopping segments.
Indian food in the UK: personal values and changing patterns of consumption
Authors: White Helen , Kokotsaki Katerini
Published: May 2004

This qualitative study examined the consumption of Indian foods among groups of English and Indian people living in the UK. Both convenience and freshly made Indian foods were included in the research. The aim was to explore attitudes (based on ethnicity) towards, and the consumption of, Indian foods. The means–end model and laddering methodology were used in interviews with 24 respondents, 12 from each group (English and Indians). The personal values ‘social life’, ‘health’, ‘adventure’, ‘enjoyment’ and ‘savings’ were found to be the most important for English respondents whereas ‘enjoyment’, ‘good life’, ‘health’, ‘religion’ and ‘culture’ were the most desirable value ends for Indians. The results provide an insight into English and Indian peoples’ perceptions of Indian food that can be used in promotion and marketing positioning of branded Indian foods, sauces and accompaniments.
The reluctant Hong Kong consumer: purchasing travel online
Authors: Kolsaker Ailsa , Lee‐Kelley Liz , Choy Pui Ching
Published: May 2004

Hong Kong consumers have embraced the web but appear reluctant to buy airline tickets online, suggesting that perceptions of risk outweigh perceived convenience. In this study we identify that both risk and convenience factors are associated strongly with willingness to purchase, particularly privacy, security and poor customer service, time savings, site usability and information provision. We identify further that the experienced shopper is only moderately satisfied and that satisfaction appears to be associated strongly with willingness to make further purchases. Overall, findings suggest that although consumers recognize a number of benefits, there is deep‐rooted resistance to buying this particular product online. The explanation may lie in a combination of the physical density of the Hong Kong market, love of the whole shopping experience and a desire to minimize risk. We conclude that to tempt consumers online airlines and agents must target the Hong Kong market with a clear value proposition which includes user‐friendly sites, streamlined payment procedures, on‐ and offline customer support, price‐related promotions and tailored offline services which reinforce online offerings.
A two‐stage stochastic integer programming model for a thermal power system expansion
Authors: Albornoz Víctor M. , Benario Pablo , Rojas Manuel E.
Published: May 2004

In this paper the obtaining of an optimum policy in the capacity expansion planning of a particular thermal‐electric power system is proposed. Therefore, a two‐stage stochastic integer programming is formulated. The model includes, through a finite group of scenarios, the existent uncertainty related to the future availability of the thermal plants currently under operation. The resultant model is solved numerically by the application of the L‐shaped method, whose implementation and development were executed using the software AMPL, with CPLEX as a solver. The results reached are shown, which validate the use of the methodology adopted in this work.
A Java™ universal vehicle router for routing unmanned aerial vehicles
Authors: Harder R.W. , Hill R.R. , Moore J.T.
Published: May 2004

We consider vehicle routing problems in the context of the Air Force operational problem of routing unmanned aerial vehicles from base locations to various reconnaissance sites. The unmanned aerial vehicle routing problem requires consideration of heterogeneous vehicles, vehicle endurance limits, time windows, and time walls for some of the sites requiring coverage, site priorities, and asymmetric travel distances. We propose a general architecture for operational research problems, specified for vehicle routing problems, that encourages object‐oriented programming and code reuse. We create an instance of this architecture for the unmanned aerial vehicle routing problem and describe the components of this architecture to include the general user interface created for the operational users of the system. We employ route building heuristics and tabu search in a symbiotic fashion to provide a user‐defined level‐of‐effort solver interface. Empirical tests of solution algorithms parameterized for solution speed reveal reasonable solution quality is attained.
Refinements on an enumeration scheme for solving a pattern sequencing problem
Authors: Yanasse H. H , Limeira M. S
Published: May 2004

We introduce some refinements on a branch‐ and bound‐scheme for solving the minimization of open stack problem (MOSP). After representing the MOSP as a graph traversing problem, we attempt to divide the graph into parts aiming to solve the resulting subgraphs independently in order to reduce the search in the branching scheme. Subgraphs with special topologies (such as trees) are solved exactly using polynomial time algorithms. The branching scheme is applied only to the parts that are ‘complex’. The refinements introduced produce substantial savings in computational time when the MOSP graph presents some special structures. Limited computational results are presented.
Fuzzy quality function deployment: determining the distributions of effort dedicated to technical change
Authors: Shipley M. F. , De Korvin A. , Yoon J‐M.
Published: May 2004

A model is presented that develops the Quality Function Deployment (QFD) House of Quality tool into a fuzzy‐set based multi‐criteria decision‐making process to determine the distributions of effort directed toward technical changes. When customers are polled for desired product‐specific attributes, the responses are typically defined by linguistic variables that represent a fuzzy set distribution. Fuzzy sets also define customer perceptions of the product attributes and technical expert opinions about product design criteria relative to marketplace competitors. Therefore, for each technical criterion, the following factors have an effect on the decision to implement change(s): (1) fuzzy sets providing evidence of customer need for attributes; (2) motivation to change to satisfy desired customer attributes; (3) motivation for technical criterion change; and (4) the strength of the relationships between the attributes and the technical criterion. Priority rankings are linked to the distributions of effort to apply in fulfilling continuous product improvement.
Interior point methods meet simplex in L, fitting problems
Authors: Oliveira A. R. L. , Lyra C.
Published: May 2004

Interior point methods specialized to the L∞ fitting problem are surveyed, improved, and compared with the traditional simplex approach. A primal affine‐scaling interior point method is presented, completing the affine‐scaling interior point family approach to the L∞ fitting problem. Computational complexity and data storage are reduced for interior point approaches when dealing with polynomial fitting problems. Numerical experiments indicate that interior point approaches rarely perform better than the simplex method for the tested problems. The primal affine‐scaling method presented in this paper achieved the best results among the interior point family.
A branch‐and‐bound algorithm for the three‐machine flowshop scheduling problem with bicriteria of makespan andtotal flowtime
Authors: Yeh Wei‐Chang , Allahverdi Ali
Published: May 2004

This paper addresses the three‐machine flowshop scheduling problem with a bicriteria of minimizing a weighted sum of makespan and total flowtime. Three lower bounds, an upper bound, and several dominance relations are developed. The upper bound is developed using a two‐phase hybrid heuristic method. A branch‐and‐bound algorithm, incorporating the developed bounds and dominance relations, is presented. An extensive computational analysis on randomly generated problems is conducted. The analysis indicates that the proposed bounds, dominance relations, and branch‐and‐bound algorithm are efficient.
A note on defective units in an inventory model with sub‐lot sampling inspection for variable lead‐time demand with the mixture of free distributions
Authors: Wu J‐W. , Lee W.‐C. , Tsai H.‐Y.
Published: May 2004

In a recent paper Wu and Ouyang (2000) assumed that an arriving order lot may contain some defective items and considered that the number of defective items in the sub‐lot sampled to be a random variable. They derived a modified mixture inventory model with backorders and lost sales, in which the order quantity, re‐order point, and the lead‐time were decision variables. In their studies they assumed that the lead‐time demand followed a normal distribution for the first model and relaxed the assumption about the form of the distribution function of the lead‐time demand for the second model. When the demand of the different customers is not identical with regard to the lead‐time, then one cannot use only a single distribution (such as Wu and Ouyang (2000)) to describe the demand of the lead‐time. Hence, we extend and correct the model of Wu and Ouyang (2000) by considering the lead‐time demand with the mixed normal distributions (see Everitt and Hand (1981), and Wu and Tsai (2001)) for the first model and the lead‐time demand with the mixed distributions for the second model. And we also apply the minimax mixed distributions free approach to the second model. Moreover, we also develop an algorithm procedure to obtain the optimal ordering strategy for each case.
Performance Evaluation Of U.K. Unit Trusts Within The Stochastic Discount Factor Framework
Authors: Fletcher Jonathan , Forbes David N.
Published: May 2004

We examine the performance of U.K. unit trusts between January 1982 and December 1996 within the stochastic discount factor approach across a wide class of models. No one model dominates the others in correctly pricing passive portfolios or detecting superior performance for hypothetical trading strategies. We find no evidence of significant superior performance by the unit trusts for any model of the stochastic discount factor. Also, the charges of the trust have a mixed effect on trust performance.
Do Demand Curves for Small Stocks Slope Down?
Authors: Biktimirov Ernest N. , Cowan Arnold R. , Jordan Bradford D.
Published: May 2004

Stocks added to the S&P 500 generally experience positive abnormal returns following the announcement. Several competing explanations exist for this reaction, but small sample sizes and other issues make it difficult to distinguish among them. We examine this subject using the small‐cap Russell 2000 index, which has several advantages over the S&P 500 in this context. Our primary finding is that stocks added to or deleted from the Russell 2000 experience significant changes in stock price and trading volume, but the effect is transitory. The results support the price pressure hypothesis.
Free Float And Market Liquidity: A Study Of Hong Kong Government Intervention
Authors: Chan Kalok , Chan Yue‐Cheong , Fong Wai‐Ming
Published: May 2004

The August 1998 Hong Kong government intervention in the stock market offers a natural experiment for studying the relation between a free float and market liquidity, where a free float is the portion of listed share capital that is freely traded on the market. Our findings show that, relative to a group of control stocks, there was an increase in the price effects of trades for the 33 Hang Seng Index component stocks that were bought by the government. On the other hand, there was no clear cross‐sectional relation between the change in the price effect and the magnitude of government holdings or the decrease in the free float.
Board Composition And Corporate Use Of Interest Rate Derivatives
Authors: Borokhovich Kenneth A. , Brunarski Kelly R. , Crutchley Claire E. , Simkins Betty J.
Published: May 2004

We provide new evidence on the motives for corporate hedging by examining the relation between the quality of the firms' monitoring mechanisms and the quantity of interest rate derivatives employed. Because the capital structure decision and hedging decision are considered to be endogenous, the firm's capital structure and level of interest rate derivative use are modeled simultaneously. We show a positive relation between the relative influence of outside directors and the quantity of derivatives used. This evidence indicates that outside directors take an active role in derivatives usage and that firms employ hedging in the shareholders' best interests.
Unit Ipos: The Who, When, And Why Of Warrant Amendment
Authors: Garner Jacqueline L. , Marshall Beverly B.
Published: May 2004

Although unit initial public offering (IPO) firms reserve the right to amend the original terms of their warrants, only some choose to extend the exercise period, lower the exercise price, or both. We examine the extent of warrant amendment among unit IPOs and find that the decision to amend is related to the need for cash and is generally employed when share prices are closer to the original warrant exercise prices. Furthermore, extension is less likely when the firm is riskier, whereas higher levels of insider ownership significantly reduce the likelihood that a firm will lower the exercise price.
Does Information Asymmetry Explain The Diversification Discount?
Authors: Best Ronald W. , Hodges Charles W. , Lin Bing‐Xuan
Published: May 2004

We examine the diversification discount while controlling for differences in information asymmetry between diversified and nondiversified firms. We show that both diversified and nondiversified firms with higher levels of information asymmetry have discounted firm values relative to firms with lower levels of information asymmetry, although a diversification discount remains at all levels of information asymmetry. Fixed‐effect Fama‐MacBeth regressions confirm the existence of a statistically significant relation between information asymmetry proxies and excess value, but they also show that a significant diversification discount remains after controlling for differences in information asymmetry and other firm characteristics discussed in earlier studies (e.g., size, profitability, leverage, and capital constraint).
Convexity: A Comparison And Reconciliation Of Its Different Forms
Authors: D'Antonio Louis , Cook Thomas J.
Published: May 2004

In this article we compare and reconcile the measures of convexity presented by several authors. We also examine the effect annual and semi‐annual periods have on the relations among the various functional forms. We show that although Garbade's measure of convexity does not represent a measure of the curvature of the price‐to‐yield function, it is a critical part of other measures that do. We demonstrate the effect that different definitions can have on evaluating basic bond characteristics.
Anomalies: Is it the Economy?
Authors: Hahn TeWhan , O'Neill Michele , Reyes Mario G.
Published: May 2004

There is still no consensus on whether small firm or value stock anomalies exist. We examine the last half of the 20th century and apply a six‐factor macroeconomic model to test for the presence of these abnormal returns. Using four proxies for value, we find that detecting this anomaly is sensitive to choice of proxy, the magnitude of the abnormal returns varies over time, and the anomaly does not persist through time. Additional tests provide evidence that abnormal returns for small, value‐oriented, and growth‐oriented firms differ significantly under restrictive versus expansive monetary policy regimes.
Recovering Enhanced Resolution Images And Digital Elevation Models From Compressed Image Sequences
Authors: Scarmana Gabriel , Fryer John G.
Published: May 2004

A device‐independent algorithm for the estimation of an enhanced resolution image from a low‐resolution compressed sequence is proposed. The algorithm utilises least squares matching to extract the interdependence of the low‐resolution images. This algorithm also has the effect of attenuating compression artefacts. Improving the spatial resolution of the image sequence is not the only goal of the enhancement algorithm, as the enhanced images in turn lead to digital elevation models (DEMs) of improved accuracy.

Experimental results illustrate the algorithm's performance as a tool for digital photogrammetric applications. Stereoscopic sets of left and right images were taken of objects of known geometry and DEMs were created using both the original coarse images and compressed images enhanced by the algorithm.
Misleading information from direct interpretation of Geometrically Incorrect aerial photographs
Authors: Rocchini Duccio
Published: May 2004

Remote sensing represents a powerful method to study the change of several phenomena over time. However, useful input data (for example, aerial photos) can produce misleading information if an inadequate geometric correction is applied. Among mathematical models used for this type of correction, orthorectification (differential correction) seems to be the only one that guarantees accurate results. However, many authors are still basing their results on incorrectly transformed images. This phenomenon is especially due to the incidence of several user‐friendly tools and interfaces for the rectification of images. This paper tests both polynomial rectification and orthorectification. Aerial photography of 1954 of the same area was acquired and polynomial rectification and orthorectification were applied, using a 1998 orthophoto as a base. An unsupervised classification was performed by utilising the nearest neighbour method for the resampling of images. The area occupied by each class was calculated. A multitemporal analysis was then performed, considering the overlap between the 1954 orthophoto and the 1998 orthophoto as the base of reference. An overestimate up to 21% of class area was found. When multitemporal analysis was carried out, an overestimate up to 100% of class area change was found.
Photogrammetric recording of the Roman earthworks ‘‘Cawthorn camps’’, north yorkshire
Authors: Stone Jane L. , Clowes Michael
Published: May 2004

Cawthorn Camps is a Roman site of probable late 1st and early 2nd century date comprising two forts, one with a later annexe, and a camp. The site survives as earthworks and, within the main defences, there are many slight embanked structures. The current multidisciplinary programme of research has included geophysical prospection, excavation, ground and aerial survey; it is a joint initiative by the North York Moors National Park Authority and English Heritage. The project aims to increase academic understanding, improve information available to the public and assist the production of a revised management plan for this nationally important site.

Large‐scale air photographs and digital photogrammetry have been used to produce a plan, at scale 1:500, of the earthworks to a precision of ±10 cm. This plan has been used as a base map with which to rectify other key photographs and plans allowing further detailed interpretation and mapping to be undertaken. The air photographic work has also investigated some of the products available through digital photogrammetric technology, such as digital elevation models (DEMs), orthophotographs and perspective views.
The Application Of Short‐Range 3d Laser Scanning For Archaeological Replica Production: The Egyptian Tomb Of Seti I
Authors: Ahmon Jess
Published: May 2004

High‐resolution 3D laser scanning in combination with industrial fabrication techniques can be used to make accurate replicas for the heritage sector. Copies may have a reputation for being inferior to the original, but by using digital technology very convincing results can be achieved to a resolution of a fraction of a millimetre. Replicas of caves at Lascaux and Altamira have already been used to help protect the original sites from the risks posed by heavy visitor numbers. Now the same principle is to be applied to the tomb of Seti I in the Valley of the Kings, Egypt. A pilot project was undertaken to produce a full‐sized replica of a 16 m2 section of the burial chamber of the tomb. The aim was to use laser scanning and digital photography to record the tomb at the highest possible resolution, then to output the data as a 3D relief using industrial routing techniques. Finally, the relief was printed in full colour. This paper describes the production of the replica including a description of the Seti Scanner, the laser scanning system specifically designed for this project.
Accuracy assessment of QuickBird stereo imagery
Authors: Noguchi Mayumi , Fraser Clive S. , Nakamura Takayuki , Shimono Takahiro , Oki Shoichi
Published: May 2004

The Geographical Survey Institute of Japan has recently carried out an evaluation of the metric performance of QuickBird stereo satellite imagery. This paper describes the accuracy assessment of the sensor orientation and geopositioning phases of the study, the aim of which was twofold. First, it was desired to confirm the metric potential of QuickBird imagery for 1:25 000 scale topographic mapping. Second, a determination was to be made of the accuracy attainable from the Basic image product. The techniques of rational functions and affine bundle adjustment were employed, the former with bias compensation. The results obtained both reassert the high precision of the rational functions approach and cast doubt upon the applicability of the 3D affine model for accurate geopositioning from QuickBird imagery.
Mast cells – a role in periodontal diseases?
Authors: Steinsvoll S. , Helgeland K. , Schenck K.
Published: May 2004

Objectives:

Limited attention has been given to the role mast cells may play in periodontal diseases.

Background:

Mast cells are indeed found abundantly below and within several types of mucosal epithelia. On the basis of their proteinase content, mast cells are divided into connective tissue (CT) and mucosal phenotypes. The CT phenotype contains both tryptase and chymase (MCTC), while the mucosal phenotype contains only tryptase (MCT). The in vivo significance of different mast cell phenotypes has not yet been fully established. Mast cells are able to phagocytose, process and present antigens as effectively as macrophages.

Results:

Recently mast cells were found in high numbers in chronically inflamed gingival tissue taken from patients with chronic marginal periodontitis (CMP). The number of mast cells was found to be even higher in HIV+ patients with CMP. Furthermore, mast cells also express strongly matrix metalloproteinases (MMPs), which are key enzymes in degradation of gingival extracellular matrix. Mast cells may release preformed cytokines directing local innate and adaptive immune responses. The present review will focus on possible roles for mast cells in periodontal diseases.

Conclusions:

We certainly feel that this is a key cell in inflamed periodontal tissue and its role in periodontitis needs to be revisited.
On the Etiology of Contact/Occupational Vitiligo
Authors: Boissy Raymond E. , Manga Prashiela
Published: May 2004

Vitiligo is an acquired depigmentary disorder of the skin that results from the selective destruction of melanocytes, generally during the second decade of life and affecting approximately 1% of the population worldwide. Loss of cutaneous pigment appears to render the skin susceptible to premature aging and cancer. In addition this disease can be socially devastating for afflicted individuals. The etiology of vitiligo is poorly understood. The present dogma suggests that genetic factors render the melanocyte fragile thus predisposing individuals to developing vitiligo. When subjected to instigating factors, these susceptible, fragile melanocytes undergo apoptosis. Autoimmune factors then perpetuate the removal of the melanocyte component from the skin. In the majority of cases the instigating factors are not known (idiopathic vitiligo), however a small sub‐set of individuals develop contact/occupational vitiligo following exposure to particular chemicals. Many of these chemicals have been implicated in both contact/occupational vitiligo and chemical leukoderma. Both conditions present with well‐defined, depigmented skin lesions that develop following exposure. Only in the case of vitiligo does the depigmentation spread beyond the areas of contact, probably via an immune‐mediated mechanism. The largest class of chemicals known to trigger contact/occupational vitiligo is the phenolic/catecholic derivatives. Many have been demonstrated to be preferentially cytotoxic to melanocytes, with high‐dose exposure resulting in the initiation of apoptosis. Phenolic/catecholic derivatives are structurally similar to the melanin precursor tyrosine, and therefore tyrosinase was originally implicated as a mediator of cytotoxicity. However, our data suggests that tyrosinase‐related protein‐1, rather than tyrosinase, facilitates toxicity, possibly by catalytic conversion of the compounds, which results in the generation of radical oxygen species. The ensuing oxidative stress then triggers activation of cellular free radical scavenging pathways to prevent cell death. Genetic inability of melanocytes to tolerate and/or respond to the oxidative stress may underlie the etiology of contact/occupational vitiligo.
Melanins and Melanosomes From Llama (Lama glama L.)
Authors: Cecchi Teresa , Cozzali Claudia , Passamonti Paolo , Ceccarelli Piero , Pucciarelli Filippo , Gargiulo Anna Maria , Frank Eduardo Nargiso , Renieri Carlo
Published: May 2004

Analysis of melanins and melanosomes in eight hair and skin samples taken of adult pigmented Argentine llamas (Lama glama L.) has been carried out. In each sample, eumelanins, pheomelanins and alkali‐soluble melanins were identified. The total amount of melanins and the amount of eumelanins both decreased from black to reddish brown colour, while pheomelanins were found to be present in small quantities in each sample. Eumelanosomes were round and oval‐shaped, displaying transverse striations clearly visible at low magnification. Dark brown samples revealed all four melanosomes stages. Stages I and II melanosomes appeared as large, asymmetrical vacuoles containing numerous microvesicles randomly scattered within an amorphous proteinaceous material (vesiculo‐globular bodies). Stage III melanosomes had microgranular melanin deposits in the microvesicles and in the matrix. The fully melanized melanosomes (stage IV) were primarily round‐shaped, showing an irregular outline and the electron‐dense pigment was arranged to form large clusters. In light brown melanocytes, numerous melanosomes at different maturation stages could be found. Premelanosomes appeared ovoid, containing amorphous proteinaceous material and spotty and microgranular deposits. Mature melanosomes were fully melanized, homogeneously electron‐dense, ovoid granules.
CTAB–Urea Method Purifies RNA from Melanin for cDNA Microarray Analysis
Authors: Stefania Lagonigro M. , Cecco Loris De , Carninci Piero , Stasi Delia Di , Ranzani Tiziana , Rodolfo Monica , Gariboldi Manuela
Published: May 2004

Melanin represents a major problem for the study of melanoma by microarrays since it is retained during RNA extraction and inhibits the enzymatic reactions used for probe preparation. Here we report a new method for cleaning RNA from melanin, based on the use of the cationic detergent cetyl‐trimethylammonium bromide (CTAB)–urea for RNA precipitation. This method is easy to perform and has a low cost. Purified RNA is recovered with high quality and good yield. CTAB–urea treated RNA from highly pigmented melanoma cells can be successfully reverse transcribed and labeled to obtain probes which can be subsequently used in cDNA microarray experiments, giving consistent and reproducible results.
Rebound Hypersecretion after Inhibition of Gastric Acid Secretion
Authors: Qvigstad Gunnar , Waldum Helge
Published: May 2004

Abstract: Drugs inhibiting gastric acid secretion are widely used because of the high prevalence of acid‐related disorders. However, from clinical experience it seems that symptom relapse is common after withdrawal of these drugs. Experimental as well as clinical studies have demonstrated an increased acid secretion after a period of treatment with either histamine 2 receptor antagonists or proton pump inhibitors. Rebound hypersecretion is likely to reflect the following sequence of events: Long‐term inhibition of acid output is accompanied by elevated serum gastrin levels, leading to enterochromaffin‐like cell activation and proliferation, resulting in increased amounts of histamine being mobilized from these cells to stimulate the parietal cells. The clinical consequences of rebound hypersecretion have not been settled.
Acidification alters Antiarrhythmic Drug Blockade of the ether‐a‐go‐go‐related Gene (HERG) Channels
Authors: Dong De‐Li , Li Zhe , Wang Hui‐Zhen , Du Zhi‐Min , Song Wei‐Hua , Yang Bao‐Feng
Published: May 2004

Abstract: Acidosis is one of the important deleterious factors during myocardial ischaemia and reperfusion. The ether‐a‐go‐go‐related gene, HERG, is a primary target for blockade by many drugs including dofetilide, quinidine and azimilide. While most drugs lose their efficacy against arrhythmias associated with myocardial ischaemia and reperfusion, dofetilide remains effective. The unique ability of dofetilide to terminate ischaemia‐induced arrhythmias is not yet fully explained. The aim of the present study is to elucidate the acidification modulation of antiarrhythmic drugs blockade of HERG channels. The human gene HERG encoding K+ channels were expressed in Xenopus oocytes, and Whole‐cell macroscopic currents of Xenopus oocytes were recorded with conventional two‐electrode techniques. The inhibitory effects of dofetilide (0.25 μM) were significantly enhanced with decreasing pH (from 7.5 to 6.5). The percent block of dofetilide under pH 6.5 at 0 mV was 69±6.1% versus 54±3.0% under pH 7.5 (n=7, P<0.05). The IC50 values, determined by the Hill equation with the currents recorded at 0 mV, were decreased by approximately half from 192±23 nM with pH 7.5 to 93±15 nM with pH 6.5 (P<0.01). Acidification weakened the inhibitory effects of quinidine and azimilide on HERG channels. At 0 mV, the percent block of quinidine (10 μM) under pH 6.5 was 24±2.8% versus 62.5±9.0% under pH 7.5 (n=4, P<0.01), The percent block of azimilide (10 μM) under pH 6.5 was similar to that under pH 7.5 (n=6). Acidification markedly potentiated dofetilide blockade of the HERG channels but weakened the inhibitory effects of quinidine and azimilide.
N‐Acetylcysteine does not Protect HepG2 Cells against Acetaminophen‐Induced Apoptosis
Authors: Manov Irena , Hirsh Mark , Iancu Theodore C.
Published: May 2004

Abstract:Acetaminophen in large doses is well‐known as hepatotoxic, and early therapy with N‐acetylcysteine is frequently life‐saving. However, in later stages of acetaminophen poisoning, treatment with N‐acetylcysteine is not always effective. Although some of the pathways of acetaminophen toxicity and the effect of N‐acetylcysteine have been elucidated, in depth information on this process is still lacking. Hepatoma‐derived HepG2 cultured cells were exposed to acetaminophen (5 and 10 mM), with or without N‐acetylcysteine (5 mM), for 24 and 48 hr. For the assessment of oxidative damage, apoptosis and necrosis, we followed redox status, glutathione content, nuclear fragmentation, phosphatidylserine externalization and ultrastructural changes. Variations in Ca2+level and number of mitochondrial dense granules were also studied. Acetaminophen treatment of HepG2 cells caused oxidative damage and apoptosis. Significant decrease of cellular redox potential and glutathione content were time‐ and concentration‐dependent. The protective effect of N‐acetylcysteine was expressed by an increase of intracellular glutathione and of the level of metabolic reduction of the redox indicator Alamar Blue. The apoptogenic effect of acetaminophen was assessed by flow cytometry of annexin V binding, nuclear hypodiploidity, intracellular Ca2+, as well as by ultrastructural examination. Beyond 24 hr of acetaminophen exposure, necrosis was also noticed. We conclude that acetaminophen‐induced oxidative damage in HepG2 cultured cells can be prevented by exposure to N‐acetylcysteine. However, apoptosis, either early or late, here demonstrated, is not avoided by exposure to N‐acetylcysteine. N‐Acetylcysteine did not prevent acetaminophen‐induced plasma membrane asymmetry, nuclear damage, alterations of Ca2+homeostasis and ultrastructural changes.
Reproductive and Cytogenetic Toxicity of Metronidazole in Male Mice
Authors: El‐Nahas Abeer F. , El‐Ashmawy Ibrahim M.
Published: May 2004

Abstract: The purpose of this study was to examine the effects of metronidazole (500 mg/kg b.wt. daily by gavage for 14 consecutive days) on male fertility, haematopoiesis and genotoxic affinity. Mature male Swiss mice were treated with metronidazole and divided into 3 groups each with 10 animals, examined after 2 weeks, 1 and 2 months from the onset of drug administration. The results demonstrated that metronidazole significantly (P<0.05) decreased the weight of the testes, epididymides and accessory sexual organs (seminal vesicles and prostates) after one month from the onset of treatment. While accessory sexual organ weights were restored after 2 months from onset of treatment, the decrease in testes and epididymides weights persisted until 2 months later. The deleterious effects of metronidazole on reproductive organ weights might be due to a decrease in testosterone level after 2 weeks, and 1 and 2 months from the onset of treatment. Metronidazole induced a significant decrease in motile sperm and an increase in abnormal sperm after 1 month. The viability of sperm was normal after 2 months. Metronidazole induced anaemia characterized by decreased erythrocyte and leukocytic counts, haemoglobin content and haematocrit %. The ability of oral metronidazole administration to induce genotoxic damage in somatic cells of mice was evaluated using mitotic index, micronuclei and chromosomal aberration. A significant reduction in mitotic activity was observed two weeks from the onset of drug administration, restoration occured after one month. A significant and persistence increase in the frequency of chromosomal aberration and micronucleus was observed at all periods of the experiment. In conclusion, the results of this study indicate that 1) metronidazole (500 mg/kg by gavage) for 14 days caused a harmful effect on male fertility in mice after one and two months from start of administration, 2) metronidazole induced anaemia after one month from start of administration, 3) metronidazole at this high dose level (3 times the therapeutic dose in mice) has the ability to induce genotoxic effects in somatic cells.