bluuebunny/crossref_metadata_2025 huggingface dataset:
Report of the Asia–Pacific consensus on the management of gastroesophageal reflux disease
Authors: FOCK KWONG MING , TALLEY NICK , HUNT RICHARD , FASS RONNIE , NANDURKAR SANJAY , LAM SHIU‐KUM , GOH KHEAN LEE , SOLLANO JOSE
Published: March 2004

This report summarizes the conclusions and recommendations of a panel of gastroenterologists practising in the Asia–Pacific region. The group recognized that although gastroesophageal reflux disease (GERD) is less common and milder in endoscopic severity in Asia than in the West, there is nevertheless data to suggest an increasing frequency of the disease. During a 2‐day workshop, the evidence for key issues in the diagnosis and clinical strategies for the management of the disease was evaluated, following which  the  recommendations  were  made  and  debated.  The  consensus  report  was  presented  at  the Asia–Pacific Digestive Week 2003 in Singapore for ratification. Upper gastrointestinal (GI) endoscopy is the gold standard for the diagnosis of erosive GERD. There is no gold standard for the diagnosis of non‐erosive GERD (NERD). Diagnosis therefore relies on symptoms, a positive 24‐h pH study or a response to a course of proton pump inhibitor (PPI) treatment. The goals of treatment for GERD are to heal esophagitis, relieve symptoms, maintain the patient free of symptoms, improve quality of life and prevent complications. The PPI are the most effective medical treatment. Following initial treatment, on‐demand therapy may be effective in some patients with NERD or mild (GI) erosive esophagitis. Anti‐reflux surgery by a competent surgeon could achieve a similar outcome, although there is an operative mortality of 0.1–0.8%. The decision is dependent on the patient's preference and the availability of surgical expertise. Currently, endoscopic treatment should be performed only in the context of a clinical trial. Treatment of patients with typical GERD symptoms without alarm features in primary care could begin with PPI for 2 weeks followed by a further 4 weeks before going to on‐demand therapy.
Autoassociator networks: insights into infant cognition
Authors: Sirois Sylvain
Published: March 2004

This paper presents autoassociator neural networks. A first section reviews the architecture of these models, common learning rules, and presents sample simulations to illustrate their abilities. In a second section, the ability of these models to account for learning phenomena such as habituation is reviewed. The contribution of these networks to discussions about infant cognition is highlighted. A new, modular approach is presented in a third section. In the discussion, a role for these learning models in a broader developmental framework is proposed.
Hebbian learning and development
Authors: Munakata Yuko , Pfaffly Jason
Published: March 2004

Hebbian learning is a biologically plausible and ecologically valid learning mechanism. In Hebbian learning, ‘units that fire together, wire together’. Such learning may occur at the neural level in terms of long‐term potentiation (LTP) and long‐term depression (LTD). Many features of Hebbian learning are relevant to developmental theorizing, including its self‐organizing nature and its ability to extract statistical regularities from the environment. Hebbian learning mechanisms may also play an important role in critical periods during development, and in a number of other developmental phenomena.
Modeling developmental transitions in adaptive resonance theory
Authors: Raijmakers Maartje E.J. , Molenaar Peter C.M.
Published: March 2004

Neural networks are applied to a theoretical subject in developmental psychology: modeling developmental transitions. Two issues that are involved will be discussed: discontinuities and acquiring qualitatively new knowledge. We will argue that by the appearance of a bifurcation, a neural network can show discontinuities and may acquire qualitatively new knowledge. First, it is shown that biological principles of neurite outgrowth result in self‐organization in a neural network, which is strongly dependent on a bifurcation in the activity dynamics. Second, the effect of a bifurcation due to morphological change is investigated in an Adaptive Resonance Theory (ART) network. Exact ART networks with quantitative differences in network structure at the category level show qualitatively different dynamical regimes, which are separated by bifurcations. These qualitative differences in dynamics affect the cognitive function of Exact ART: Representations of learned categories are local or distributed.
Evolving agents as a metaphor for the developing child
Authors: Schlesinger Matthew
Published: March 2004

The emerging field of Evolutionary Computation (EC), inspired by neo‐Darwinian principles (e.g. natural selection, mutation, etc.), offers developmental psychologists a wide array of mathematical tools for simulating ontogenetic processes. In this brief review, I begin by highlighting three of the approaches that EC researchers employ (Artificial Life, evolutionary robotics and comparative stochastic optimization). I then focus on the advantages of using comparative stochastic optimization as a method for studying development. As a concrete example, I illustrate the design and implementation of an EC model that simulates the development of reaching in young infants.
‘Core Knowledges’: a dissociation between spatiotemporal knowledge and contact‐mechanics in a non‐human primate?
Authors: Santos Laurie R.
Published: March 2004

Human toddlers demonstrate striking failures when searching for hidden objects that interact with other objects, yet successfully locate hidden objects that do not undergo mechanical interactions. This pattern hints at a developmental dissociation between contact‐mechanical and spatiotemporal knowledge. Recent studies suggest that adult non‐human primates may exhibit a similar dissociation. Here, I provide the first direct test of this dissociation using a search paradigm with adult rhesus monkeys. Subjects watched as a plum rolled behind one of two opaque barriers. In Experiment 1, subjects had to locate the plum based on the position of a wall that blocked the plum's trajectory. Subjects searched incorrectly, apparently neglecting information about the location of the wall. However, subjects searched correctly in Experiments 2–4 when they were given spatiotemporal information about the plum's movement. Results indicate that adult monkeys use spatiotemporal information, but not contact‐mechanical information, to locate hidden objects. This dissociation between contact‐mechanical and spatiotemporal knowledge is discussed in light of developmental theories of core knowledge and the literature on object‐based attention in human adults.
Perception of serial order in infants
Authors: Lewkowicz David J.
Published: March 2004

Serial order is fundamental to perception, cognition and behavioral action. Three experiments investigated infants’ perception, learning and discrimination of serial order. Four‐ and 8‐month‐old infants were habituated to three sequentially moving objects making visible and audible impacts and then were tested on separate test trials for their ability to detect auditory, visual or auditory‐visual changes in their ordering. The 4‐month‐old infants did not respond to any order changes and instead appeared to attend to the ‘local’ audio‐visual synchrony part of the event. When this local part of the event was blocked from view, the 4‐month‐olds did perceive the serial order feature of the event but only when it was specified multimodally. In contrast, the 8‐month‐old infants perceived all three kinds of order changes regardless of whether the synchrony part of the event was visible or not. The findings show that perception of spatiotemporal serial order emerges early in infancy and that its perception is initially facilitated by multimodal specification.
A test of the generality of perceptually based categories found in infants: attentional differences toward natural kinds by New World monkeys
Authors: Neiworth Julie J. , Parsons Richard R. , Hassett Janice M.
Published: March 2004

A preference to novelty paradigm used to study human infants (Quinn, 2002) examined attention to novel animal pictures at subordinate, basic and superordinate levels in tamarins. First, pairs of pictures were presented in phases, starting with a monkey species (subordinate level) and ending with mammal and dinosaur sets (superordinate levels). After each phase, tests paired novel pictures from the familiarized set with a novel broader category. Look rates toward each picture were coded. Tamarins looked significantly longer at a novel species after being familiarized with a monkey species, a species‐specific effect. Subjects attended equivalently to novel primate species after habituation to four monkey species, but looked significantly longer at pictures of mammals, marking a more global‐level inclusion and exclusion. Superordinate testing revealed that more novel and diverse sets were differentiated attentionally. The evidence implies that natural categorical representation occurs at an attentional level in primates in ways similar to human infants, and is affected by recent exposure and category variability.
The dynamics of infant visual foraging
Authors: Robertson Steven S. , Guckenheimer John , Masnick Amy M. , Bacher Leigh F.
Published: March 2004

Human infants actively forage for visual information from the moment of birth onward. Although we know a great deal about how stimulus characteristics influence looking behavior in the first few postnatal weeks, we know much less about the intrinsic dynamics of the behavior. Here we show that a simple stochastic dynamical system acts quantitatively like 4‐week‐old infants on a range of measures if there is hysteresis in the transitions between looking and looking away in the model system. The success of this simple three‐parameter model suggests that visual foraging in the first few weeks after birth may be influenced more by noise and hysteresis in underlying neural mechanisms than by how infants process visual information after a look begins.
Origins of a stereotype: categorization of facial attractiveness by 6‐month‐old infants
Authors: Ramsey Jennifer L. , Langlois Judith H. , Hoss Rebecca A. , Rubenstein Adam J. , Griffin Angela M.
Published: March 2004

Like adults, young infants prefer attractive to unattractive faces (e.g. Langlois, Roggman, Casey, Ritter, Rieser‐Danner & Jenkins, 1987; Slater, von der Schulenburg, Brown, Badenoch, Butterworth, Parsons & Samuels, 1998). Older children and adults stereotype based on facial attractiveness (Eagly, Ashmore, Makhijani & Longo, 1991; Langlois, Kalakanis, Rubenstein, Larson, Hallam & Smooth, 2000). How do preferences for attractive faces develop into stereotypes? Several theories of stereotyping posit that categorization of groups is necessary before positive and negative traits can become linked to the groups (e.g. Tajfel, Billig, Bundy & Flament, 1971; Zebrowitz‐McArthur, 1982). We investigated whether or not 6‐month‐old infants can categorize faces as attractive or unattractive. In Experiment 1, we familiarized infants to unattractive female faces; in Experiment 2, we familiarized infants to attractive female faces and tested both groups of infants on novel faces from the familiar or novel attractiveness category. Results showed that 6‐month‐olds categorized attractive and unattractive female faces into two different groups of faces. Experiments 3 and 4 confirmed that infants could discriminate among the faces used in Experiments 1 and 2, and therefore categorized the faces based on their similarities in attractiveness rather than because they could not differentiate among the faces. These findings suggest that categorization of facial attractiveness may underlie the development of the ‘beauty is good’ stereotype.
The language‐specific nature of grammatical development: evidence from bilingual language learners
Authors: Marchman Virginia A. , Martínez‐Sussmann Carmen , Dale Philip S.
Published: March 2004

The fact that early lexical and grammatical acquisition are strongly correlated has been cited as evidence against the view that the language faculty is composed of dissociable and autonomous modules (Bates & Goodman, 1997). However, previous studies have not yet eliminated the possibility that lexical–grammar associations may be attributable to language‐general individual differences (e.g. children who are good at learning words are good at learning grammar). Parent report assessments of toddlers who are simultaneously learning English and Spanish (n = 113) allow an examination of the specificity of lexical–grammar relationships while holding child factors constant. Within‐language vocabulary–grammar associations were stronger than cross‐language relationships, even after controlling for age, proportion of language exposure, general language skill and reporter bias. Similar patterns were found based on naturalistic language samples (n = 22), ruling out a methodological artifact. These results are consistent with the view that grammar learning is specifically tied to lexical progress in a given language and provide further support for strong lexical–grammatical continuity early in acquisition.
Changes in reality monitoring and episodic memory in early childhood
Authors: Sluzenski Julia , Newcombe Nora , Ottinger Wendy
Published: March 2004

The purposes of this research were to examine the developmental relation between reality monitoring and episodic memory, to link reality monitoring to autobiographical memory by using extended naturalistic events, and to examine prefrontal functioning as a potential contributor to development in reality monitoring and episodic memory. In Experiment 1, 4‐year‐olds were worse than 6‐ or 8‐year‐olds at reality monitoring after a week delay, despite the fact that they remembered more about real than imagined events and remembered different aspects of each. In Experiments 2 and 3, reality monitoring and episodic memory were evaluated for 4‐ and 6‐year‐olds immediately after the events occurred and, in Experiment 3, again after a week delay. Reality monitoring was at higher levels for both age groups, but age differences remained. These data suggest that preschoolers’ difficulties with reality monitoring result from a combination of episodic memory deficits and strategic differences. In addition, correlation analyses more directly linked preschoolers’ reality monitoring to episodic memory and supported the hypothesis that episodic memory development is related to prefrontal functioning.
Face inversion and contrast‐reversal effects across development: in contrast to the expertise theory
Authors: Itier Roxane J. , Taylor Margot J.
Published: March 2004

To determine the role of configural changes on the development of face encoding and memory, we investigated face recognition in an n‐back repetition task with upright, inverted and contrast‐reversed unfamiliar faces in adults and children (8–16 years). Repetitions occurred immediately (0‐lag) or after one intervening face (1‐lag). Face recognition continued to develop beyond 14–16 years, as shown with hit rates, d’ scores and reaction times that all improved with age. Inversion and contrast‐reversal effects were found in all subjects but were not more pronounced with increasing age, suggesting no increased reliance on configural processing and thus arguing against the expertise theory of Diamond and Carey (1986). Recognition improved with age in upright but also in inverted and contrast‐reversed faces, suggesting a quantitative rather than a qualitative developmental change in face processing. For all age groups, performances decreased and reaction times increased from 0‐ to 1‐lag conditions similarly, suggesting a similar memory component involved in adults’ and children's processing. These data suggest gradual quantitative improvements in face processing with age, mainly due to increasing working memory processing capacity.
Wittgenstein on The Standard Metre
Authors: Pollock W. J.
Published: March 2004

In this paper I argue that Wittgenstein is correct when he says of the Standard Metre stick that we can neither say that it is or is not a metre in length – despite what our intuitions may tell us to the contrary. Specifically, the paper deals with Kripke's criticism of Wittgenstein's claim in Naming And Necessity and with Salmon's attempt to arbitrate between the two views. I conclude that, not only is Wittgenstein correct, but that both Kripke and Salmon (and possibly the majority of philosophers) simply do not understand the concept of measurement.
The Implications of Prospect Theory for Human Nature and Values
Authors: Jervis Robert
Published: March 2004

Central to prospect theory are far‐reaching claims about what people fear and what gratifies them. Subjective well‐being is a topic that social science has been reluctant to discuss in recent years, but it is central to much of our lives. A loss inflicts more harm than a comparable gain produces pleasure; this fact and the related endowment effect are important parts of our psychological makeup. The importance of change rather than absolute value position, and the related significance of the reference point and how it can be altered, can be seen as integral to human nature.
Power Politics and the Balance of Risk: Hypotheses on Great Power Intervention in the Periphery
Authors: Taliaferro Jeffrey W.
Published: March 2004

Great powers frequently initiate risky diplomatic and military interventions in the periphery—regions that do not directly threaten the security of a great power's homeland. Such risky interventions are driven by leaders’ aversion to losses in their state's relative power, international status, or prestige. These leaders often persist in such courses of action even when they incur mounting political, economic, and military costs. More surprisingly, they undertake risky strategies toward other great powers in an effort to continue these failing interventions. Hypotheses concerning such interventions are derived from the prospect theory and defensive realist literatures.
Framing and the Role of the Second Actor: An Application of Prospect Theory to Bargaining
Authors: Kanner Michael D.
Published: March 2004

An actor's frame of reference significantly affects that actor's risk attitude. Although the frame of reference is often taken as a given, earlier work shows it to be the result of an actor's assumptions and beliefs, which can be manipulated by a second actor in a bargaining situation. As modeled here, confidence in selected assumptions can be manipulated by one of two means: changing the confidence of the actor about the future domain, and getting the actor to adopt a particular domain by discounting the utility of a course of action. Both methods force a change in the perceived domain and a shift in risk attitude. In addition to showing manipulation of an actor's frame, the model adds to our understanding of Kahneman and Tversky's original expression of prospect theory.
Large Costs, Small Benefits: Explaining Trade Dispute Outcomes
Authors: Elms Deborah Kay
Published: March 2004

The United States frequently engages in negotiations with its trading partners over expanded market access for American firms. Although many of these negotiations involve markets worth millions or even billions of dollars, sometimes government officials bargain long and hard over issues that were never predicted to result in substantial benefits. For example, the United States held negotiations with Japan for more than 30 years over increased market access for American apples. These negotiations were ultimately carried to the highest levels of government, discussed at international conferences, and even ruled on by the World Trade Organization, yet estimates of the potential market for foreign apples never exceeded $15 million. Such protracted negotiations in this sector do not make sense from the perspective of expected utility theory but can be explained by prospect theory. Apple negotiations came to represent a spiral model for both the United States and Japan. As each side viewed its own losses as deepening over the course of negotiations, each became caught in a prospect theory spiral of actions and became willing to take even riskier actions in an attempt to recoup losses.
Crossing No Man's Land: Cooperation From the Trenches
Authors: Bueno de Mesquita Bruce , McDermott Rose
Published: March 2004

This paper represents an attempt to bridge the gap between rational and psychological models of choice, as represented by expected utility theory and prospect theory, and to show how researchers from different traditions can start to work together on problems of interest to both. A central issue for both models concerns the origin of preferences and how they might be predicted. Two questions of interest to all social scientists are related to the formation of preferences: What determines what people want, and what determines what people do once they know what they want? The incorporation of emotion into models of decision‐making may help users of divergent models find common ground for exploration and investigation.
Prospect Theory in Political Science: Gains and Losses From the First Decade
Authors: McDermott Rose
Published: March 2004

Prospect theory offers a number of advantages that justify its use in the analysis of political behavior, but it also has some aspects that limit its wider applicability in political contexts. This article reviews recent research highlighting these successes and limitations. Future research on the incorporation of prospect theory into models of political behavior should focus on such areas as group decision‐making, reference point specification, and emotion.
Differential CD4 T‐cell response in HIV‐1‐infected patients using protease inhibitor‐based or nevirapine‐based highly active antiretroviral therapy
Authors: Van Leth F , Wit FWNM , Reiss P , Schattenkerk JKME , Van Der Ende ME , Schneider MME , Mulder JW , Frissen PHJ , De Wolf F , Lange JMA
Published: March 2004

Objectives

To study the dynamics of CD4 T‐lymphocyte counts (CD4 counts) after the initiation of either protease inhibitor (PI)‐based or nevirapine (NVP)‐based first‐line highly active antiretroviral therapy (HAART).

Design and methods

A retrospective cohort study of 1029 HIV‐infected antiretroviral therapy‐naive patients initiating either PI‐based or NVP‐based HAART was carried out. Patients were censored as soon as they experienced virological failure, or changed their original antiretroviral regimen for any reason.

Results

In total, 920 and 109 patients initiated PI‐ and NVP‐based HAART, respectively. The patients in the PI group more often had AIDS (15 vs. 6% in the NVP group), had a lower median baseline CD4 count (234 vs. 250 cells/μL in the NVP group) and had higher median baseline plasma HIV‐1 RNA levels (pVL) (5.0 vs. 4.7 log10 HIV‐1 RNA copies/mL in the NVP group). After 96 weeks of follow‐up, the mean increase from baseline in CD4 count, adjusted for baseline CD4 count, age, gender and baseline pVL, was 310 cells/μL in the PI group and 212 cells/μL in the NVP group (P=0.003). This difference was mainly attributable to the patients in the NVP group initiating HAART with a baseline CD4 count below 200 cells/μL. There were no differences between the PI and NVP groups with respect to the change in the number of CD4 cells as a proportion of the total number of lymphocytes.

Conclusion

Patients successfully treated with NVP‐based HAART have a smaller increase in absolute CD4 cells compared with those treated with PI‐based HAART.
Cardiovascular disease risk factors and antiretroviral therapy in an HIV‐positive UK population
Authors: Smith CJ , Levy I , Sabin CA , Kaya E , Johnson MA , Lipman MCI
Published: March 2004

Aim

Although the benefits of antiretroviral therapy (ART) have been dramatic, studies have started to report a variety of drug‐related side effects and toxicities. We sought to characterize the risk factors for cardiovascular disease present in an HIV‐positive population.

Methods

A total of 394 HIV‐positive ambulant patients attending the Royal Free Hospital, London, were asked to complete a questionnaire. Questions focused on smoking habits and general health.

Results

In total, 34% of patients were aged >40 years, 29% had a family history of heart disease, 3% had diabetes, 14% suffered from raised blood pressure, 20% had a body mass index (BMI)>26 kg/m3, 7% had an alcohol consumption above the recommended UK limit, and 18% had total cholesterol levels >6.3 mmol/L. The rate of smoking observed (45%) was much higher than that observed amongst the general population in the British Health Survey for England (34%). There were significant differences between those receiving and not receiving ART. Those on ART tended to be younger (P<0.0001) and less likely to smoke cigarettes (P=0.06) or have an alcohol consumption above the recommended limit (P=0.08), but were more likely to have diabetes (P=0.05). More patients receiving ART reported, and so perceived themselves to have, raised blood fats (P<0.0001). This was confirmed when considering blood lipid levels, where those on ART had significantly raised total cholesterol levels compared to those not currently receiving ART (P<0.0001).

Conclusion

We have demonstrated an excess of cardiovascular risk factors in this cohort. These issues must be addressed if we wish to maintain the benefit of treating HIV infection.
Pharmacokinetics of emtricitabine, didanosine and efavirenz administered once‐daily for the treatment of HIV‐infected adults (pharmacokinetic substudy of the ANRS 091 trial)*
Authors: Molina J‐M , Peytavin G , Perusat S , Lascoux‐Combes C , Sereni D , Rozenbaum W , Chene G
Published: March 2004

Objective
This study was conducted to investigate the pharmacokinetics of emtricitabine (FTC), didanosine (ddI), and efavirenz (EFV) when administered in a once‐daily combination.

Methods
Nine antiretroviral‐naïve HIV‐infected adults who received FTC [200 mg once a day (qd)], ddI (400 mg qd if ≥60 kg; 250 mg qd if <60 kg) and EFV (600 mg qd) were studied. The following pharmacokinetic (PK) parameters were determined over 24 h at steady‐state after 4 weeks of treatment: area under the plasma concentration vs. time curve (AUC0–24 h), maximum (Cmax) and minimum (Cmin) plasma concentrations, time to reach Cmax (Tmax), and the elimination half‐life (t1/2). EFV plasma concentrations were also measured during follow‐up.

Results
Median PK parameters for FTC, ddI and EFV, respectively, were as follows. AUC0–24 h: 7.2, 7.0 and 36.4 h×mg/L; Cmax: 1.8, 2.6 and 2.5 mg/L; Cmin: 0.04, < 0.01 and 1.0 mg/L; Tmax: 1.8, 1.1 and 2.5 h; t1/2: 7.4, 2.3, and 23.7 h. EFV plasma concentrations measured 10–13 h postdosing were higher during follow‐up than during the PK study (2.57 vs. 1.19 mg/L, P<0.01).

Conclusion
The simultaneous administration of FTC, ddI and EFV did not affect the PK parameters of FTC when compared to historical controls. EFV Cmax and Cmin were lower than expected, but the data may have been slightly underestimated in this study. High ddI AUC and Cmax were measured in these patients, and further studies are warranted to confirm this finding.
Evaluating digital libraries in the health sector. Part 2: measuring impacts and outcomes
Authors: Cullen Rowena
Published: March 2004

This is the second part of a two‐part paper which explores methods that can be used to evaluate digital libraries in the health sector. Part 1 focuses on approaches to evaluation that have been proposed for mainstream digital information services. This paper investigates evaluative models developed for some innovative digital library projects, and some major national and international electronic health information projects. The value of ethnographic methods to provide qualitative data to explore outcomes, adding to quantitative approaches based on inputs and outputs is discussed. The paper concludes that new ‘post‐positivist’ models of evaluation are needed to cover all the dimensions of the digital library in the health sector, and some ways of doing this are outlined.
Should systematic reviews include searches for published errata?
Authors: Royle Pamela , Waugh Norman
Published: March 2004

Our objective was to perform a pilot study to estimate the proportion of published errata linked to randomized controlled trials (RCTs) that are worthwhile obtaining when doing a systematic review. medline was searched for records that had both ‘randomized‐controlled‐trial’ in the publication type field and ‘erratum’ in the comments field. One hundred records from four general medical journals were examined independently from two different perspectives. From the information specialist's perspective, 74% of the errata were considered worthwhile obtaining; these were mainly errors in tables or figures. Another 9% described less serious errors, but were worth obtaining if easily available. The other 17% were minor errors. From the perspective of the experienced reviewer/public health consultant, 5% of errata were classified as likely to affect a meta‐analysis, and 10% as having significant errors that would affect the interpretation of the RCT, but no effect on a meta‐analysis; 85% were not considered important enough to affect either. About 5% of errata to RCTs appeared to matter in terms of changing the final conclusions of a systematic review. However, the majority of errata were considered to be worthwhile obtaining, on the basis that having full and accurate data can reduce confusion and save reviewers time.
Library service delivery via hand‐held computers—the right information at the point of care
Authors: Peterson Mary
Published: March 2004

Today's health and medical librarians are well aware of the move towards evidence‐based clinical practice which has emerged during the past decade. Hand‐in‐hand with this trend is the need for health practitioners to have access to the best possible evidence to help them in their clinical decision making. Libraries have a key role in the provision of information to their clients, and this means keeping abreast, not only of the various information sources available, but also the means by which those sources may be used. This paper will examine the effects that the hand‐held computer is having on the work practices of our clients—library users. It is hoped that the paper will give an insight into the various types of library material which are suitable for use with hand‐held devices, and an understanding of their advantages and limitations.
Awareness, use and opinions of methodological search filters used for the retrieval of evidence‐based medical literature—a questionnaire survey
Authors: Jenkins Michelle , Johnson Frances
Published: March 2004

The aim of this study was to determine the level of awareness of methodological search filters among health and academic librarians in the UK and Ireland, their use of filters and views on the perceived benefits, limitations and ways to increase usage of search filters. A random proportional sample of health and academic librarians were surveyed by telephone and fax. Overall, 88% (196/224) completed the telephone survey to establish awareness and use of filters. Eighty‐four per cent (51/61) completed a fax survey focusing in more depth on usability issues surrounding filters. Results indicate a high level of awareness of methodological filters, but low level of usage. Furthermore, a high level of awareness did not necessarily correlate with a high level of knowledge or understanding. Examination of responses revealed limitations and recommendations beyond those reported in the literature and highlights the relationship between understanding and effective use of filters. Improved dissemination and publication of filters is required to better inform librarians on the concept of filters and how to use them effectively.
A study of medical and health queries to web search engines
Authors: Spink Amanda , Yang Yin , Jansen Jim , Nykanen Pirrko , Lorence Daniel P. , Ozmutlu Seda , Ozmutlu H. Cenk
Published: March 2004

This paper reports findings from an analysis of medical or health queries to different web search engines. We report results: (i) comparing samples of 10 000 web queries taken randomly from 1.2 million query logs from the AlltheWeb.com and Excite.com commercial web search engines in 2001 for medical or health queries, (ii) comparing the 2001 findings from Excite and AlltheWeb.com users with results from a previous analysis of medical and health related queries from the Excite Web search engine for 1997 and 1999, and (iii) medical or health advice‐seeking queries beginning with the word ‘should’. Findings suggest: (i) a small percentage of web queries are medical or health related, (ii) the top five categories of medical or health queries were: general health, weight issues, reproductive health and puberty, pregnancy/obstetrics, and human relationships, and (iii) over time, the medical and health queries may have declined as a proportion of all web queries, as the use of specialized medical/health websites and e‐commerce‐related queries has increased. Findings provide insights into medical and health‐related web querying and suggests some implications for the use of the general web search engines when seeking medical/health information.
How does your searching grow? A survey of search preferences and the use of optimal search strategies in the identification of qualitative research
Authors: Grant Maria J.
Published: March 2004

The objective was to gain an overview of researchers experiences of searching the literature, with particular reference to the use of optimal search strategies (OSSs) and searching for qualitative research studies. A 13‐item semi‐structured questionnaire investigating search behaviour was distributed to members of the Cochrane Qualitative Methods Network. Follow‐up interviews were conducted with a subset of respondents to explore issues raised and clarify points of ambiguity. Findings were analysed using data reduction, data displays and verification techniques. Eighty‐six per cent of distributed questionnaires were returned. All respondents reported searching electronic databases as part of their literature search, with 80% expressing a preference for searching alone or with colleagues. Forty‐one per cent indicated that they consider a database search to be only one aspect of a comprehensive literature search. The rigour and availability of OSSs was a concern for 30% of respondents. Twenty‐five per cent of respondents had searched for qualitative studies, although the difficulty of locating this type of literature was considered problematic because of the varied use of the term ‘qualitative’. Whilst the majority of respondents reported using OSSs in some capacity, reservations were expressed about their ability to facilitate a comprehensive search. Replies indicated a belief that OSSs can reduce the sensitivity of a search, and might limit the breadth of coverage required. A greater appreciation of the availability and purpose of OSSs—including the ability to optimize either sensitivity or recall—is needed if this enhanced approach to accurate data retrieval and potential improvement in time management is to become widespread.
Spatio‐temporal Imaging of Cortical Desynchronization in Migraine Visual Aura: A Magnetoencephalography Case Study
Authors: Hall Stephen D. , Barnes Gareth R. , Hillebrand Arjan , Furlong Paul L. , Singh Krish D. , Holliday Ian E.
Published: March 2004

Objective.—To determine cortical oscillatory changes involved in migraine visual aura using magnetoencephalography (MEG).

Background.—Visual aura in the form of scintillating scotoma precedes migraine in many cases. The involvement of cortical spreading depression within striate and extra‐striate cortical areas is implicated in the generation of the disturbance, but the details of its progression, the effects on cortical oscillations, and the mechanisms of aura generation are unclear.

Methods.—We used MEG to directly image changes in cortical oscillatory power during an episode of scintillating scotoma in a patient who experiences aura without subsequent migraine headache. Using the synthetic aperture magnetometry method of MEG source imaging, focal changes in cortical oscillatory power were observed over a 20‐minute period and visualized in coregistration with the patient's magnetic resonance image.

Results.—Alpha band desynchronization in both the left extra‐striate and temporal cortex persisted for the duration of reported visual disturbance, terminating abruptly upon disappearance of scintillations. Gamma frequency desynchronization in the left temporal lobe continued for 8 to 10 minutes following the reported end of aura.

Conclusions.—Observations implicate the extra‐striate and temporal cortex in migraine visual aura and suggest involvement of alpha desynchronization in generation of phosphenes and gamma desynchronization in sustained inhibition of visual function.
Effectiveness of Eletriptan in Acute Migraine: Primary Care for Excedrin Nonresponders
Authors: Diamond Merle L. , Hettiarachchi Jayasena , Hilliard Barbara , Sands George , Nett Robert
Published: March 2004

Objective.—To evaluate the effectiveness of eletriptan as a treatment for acute migraine in patients who were poor responders to Excedrin and had not yet been exposed to a triptan.

Background.—Self‐medication with over‐the‐counter drugs, such as Excedrin, is the most common treatment for migraine. Guidelines, however, recommend that triptans be used as first‐line treatment of moderate to severe migraine—the severity affecting approximately 80% of migraineurs. Since over‐the‐counter medications, such as Excedrin, continue to be used in many patients, it is important that clinicians have information on the efficacy of triptans as first‐line treatment and on treatment of migraineurs who have shown poor response to over‐the‐counter medications.

Methods.—One hundred ten patients meeting criteria for migraine who were poor responders to Excedrin received open‐label treatment with a 40‐mg dose of eletriptan for one migraine attack. Efficacy assessments were made at 1, 2, 4, and 24 hours postdose and consisted of headache and pain‐free response rates, absence of associated symptoms, and functional response.

Results.—At 1 hour, the headache response rate was 44%; at 2 hours, 81%. The pain‐free response rate at 1 hour was 14% and at 2 hours, 48%. At 2 hours, relief of baseline‐associated symptoms ranged from 74% to 80%. Functional response was achieved by 82% of patients by 2 hours, and 68% of patients achieved relief of migraine that was sustained across 24 hours with no need for a second dose of eletriptan or for rescue medication. Eletriptan was well tolerated with adverse events being transient and mild to moderate in intensity.

Conclusion.—Previous studies have established the efficacy of eletriptan as a first‐line treatment for migraine. The results of this open‐label trial demonstrate that the 40‐mg dose of eletriptan had a high degree of efficacy and tolerability among patients who were poor responders to Excedrin.
Factors Related to School Absenteeism in Adolescents With Recurrent Headache
Authors: Breuner Cora Collette , Smith Mark Scott , Womack William M.
Published: March 2004

Objective.—To examine possible risk and protective factors for school absenteeism among adolescents referred to a hospital‐based behavioral treatment program.

Design.—Data obtained from intake interviews, screening questionnaires, and baseline headache diaries of 283 consecutive adolescents referred for behavioral treatment of recurrent headache were reviewed for demographics, length of headache history, headache type, current headache activity, symptoms of anxiety and depression, perceived self‐efficacy regarding headache control, school performance, participation in extracurricular activities, and school absenteeism. The study population was divided into 2 groups at the median number of days missed due to headache in the previous 6 months that school was in session. Adolescents who missed 2 or less days of school due to headache (low absenteeism) were compared with those who missed more than 2 days (high absenteeism).

Results.—Compared with the low absenteeism group, the high absenteeism group had higher scores on the Children's Depression Inventory (8.7 ± 6.5 versus 6.8 ± 6.2, P < .05) and lower academic performance (2.1 ± 1.0 versus 1.7 ± 0.8, P < .0001). The 2 groups were not statistically different in age, sex, length of headache history, type of headache, current headache frequency or intensity scores, anxiety scores, self‐efficacy ratings, or participation in extracurricular activities.

Conclusions.—In a referred population, students who missed more school due to headache had higher depression scores and lower academic performance than students who missed less school. A directional relationship, however, cannot be implied from these results. Future studies should investigate the complex relationship between recurrent adolescent headache, potential risk or protective factors, and school absenteeism.
Blood Pool Scintigraphy of the Skull in Relation to Head‐Down Tilt Provocation in Patients With Chronic Tension‐Type Headache and Controls
Authors: Hannerz Jan , Schnell P.‐O. , Larsson Stig , Jacobsson Hans
Published: March 2004

Objective.—To investigate the mechanisms behind the increase of chronic tension‐type headache during head‐down tilt.

Background.—The pathophysiology of chronic tension‐type headache is unknown.

Design and Methods.—Ten patients suffering from chronic tension‐type headache and 10 age‐ and sex‐matched controls were studied with respect to pain intensity and alterations in cranial blood volume using planar scintigraphy and radiolabeled autologous erythrocytes before, during, and after head‐down tilt, a procedure known to increase chronic tension‐type headache.

Results.—Four of 8 patients with chronic tension‐type headache studied had increased cerebrospinal fluid pressure. During head‐down tilt, the pain increased significantly in the group with chronic tension‐type headache (P < .001) while the procedure did not cause headache in the controls. Blood volume significantly increased extracranially and decreased intracranially in both groups during head‐down tilt. The extracranial nasal blood volume was significantly related to the pain experienced by the patients with chronic tension‐type headache before and during head‐down tilt.

Conclusions.—Although the changes in blood volume and, presumably, the increase of intracranial pressure were similar in the patients with chronic tension‐type headache and the controls, only the patients experienced pain and pain increase during head‐down tilt. This indicates that the pre‐head‐down tilt conditions must be different in the 2 groups and should be related to increased cerebrospinal fluid pressure/intracranial venous pressure in patients with chronic tension‐type headache compared with controls. A difference in central mechanisms may, however, also be of importance for the difference in headache provocation in the 2 groups during head‐down tilt.
Prophylactic Treatment of Pediatric Migraine
Authors: Lewis Donald W. , Diamond Sharon , Scott David , Jones Valarie
Published: March 2004

Background.—Migraine occurs in 3% to 5% of young children and up to 18% of adolescents. Management requires a tailored regimen of pharmacological and behavioral measures that consider the headache burden and disability. Patients with frequent or disabling attacks (or both) may warrant preventive agents.

Objective.—To investigate the patterns of prophylactic treatment of pediatric migraine within one pediatric neurology practice.

Methods.—All charts of patients diagnosed with headache (International Classification of Diseases [ICD] code 784.0) and migraine (codes 346.0, 346.1, and 346.2) during January 2001 July 2001 were retrospectively reviewed to identify diagnosis, demographics, medical decision making, rationale for treatment selections, and outcome assessments. Migraine was diagnosed according to the 1997 proposed pediatric migraine revisions to the International Headache Society.

Results.—Charts of 250 children and adolescents, aged 3.2 to 18 years (mean, 12), were reviewed. One hundred twenty‐six (50%) were prescribed prophylaxis, along with intermittent analgesic agents. Mean age of those provided with daily prophylaxis was 12.4 years (range, 3.9 to 18), and the mean age of those managed with intermittent therapies was 11.5 years.

Preventive agents included amitriptyline (n = 73), cyproheptadine (n = 30), propranolol (n = 8), valproic acid (n = 3), naproxen (n = 3), nimodipine (n = 3), imipramine (n = 3), and topiramate (n = 3). Amitriptyline was the most commonly prescribed agent (58%). Ten patients initially treated with other agents were changed to amitriptyline. Fifteen patients required dosing adjustments, 2 stopped treatment, and 7 changed to other agents for lack of efficacy. Mean headache frequency before treatment was 10.9 per month (range, 4 to 15). After treatment, the mean headache frequency decreased to 4.1 per month (range, 0 to 12), a decrease of 62.4% (n = 54). The overall positive response rate was 89%.

Cyproheptadine was the second most commonly prescribed agent (mean age, 8.8 years). Thirty patients were initially treated, 5 later changed to cyproheptadine, 6 required dosage changes, 5 changed to other agents for lack of efficacy, and 1 stopped treatment. Mean headache frequency before treatment was 8.4 per month (range, 4 to 15) and following treatment decreased to 3.75 per month (range, 0 to 12), a decrease of 55.3%. The overall positive response rate was 83%.

Conclusions.—Fifty percent of patients with migraine were prescribed daily prophylactic medicines, reflecting a referral bias. The most commonly prescribed agents were amitriptyline (preferred for the older patients) and cyproheptadine (preferred for the younger patients). The overall positive response rates were 89% for amitriptyline and 83% for cyproheptadine during a 6‐month follow‐up. Headache frequencies were reduced with amitriptyline by 62% and with cyproheptadine by 55%. Long‐term follow‐up of this population is ongoing, and prospective studies are needed.
Efficacy and Safety of Levetiracetam in Pediatric Migraine
Authors: Miller G. Steve
Published: March 2004

Background.—Headache is a frequent occurrence among children and adolescents. Chronic headaches can be severe and disabling, and require prophylactic treatment; however, additional data on the use of prophylactic medications for migraine in children are needed.

Objective.—To review the efficacy and safety of levetiracetam (Keppra) in pediatric patients with a history of recurrent headache.

Design/Methods.—Data from 19 pediatric patients were retrospectively reviewed. The initial dose of levetiracetam was usually 125 or 250 mg twice daily, but varied depending upon clinical judgment.

Results.—Charts of 9 girls and 10 boys (mean age, 11.9 years) were reviewed. A variety of medications, including triptans, had been used before initiating treatment with levetiracetam. Mean headache frequency before treatment was 6.3 per month (standard deviation [SD], 3.8; confidence interval [CI], 4.4 to 8.1). Duration of headaches ranged from 0.25 to 8 years. Migraine (63.2%) and migraine with aura (15.8%) were the most common types of headache reported. Most patients (89.5%) had headaches that were severe. After treatment, the mean headache frequency decreased to 1.7 per month (SD, 2.7; CI, 0.4 to 3.0), representing a reduction compared with baseline (P < .0001). Levetiracetam eliminated headaches in 10 patients (52.6%), and 7 patients (36.8%) had less severe and less frequent headaches. Levetiracetam did not have an effect on headaches in 2 patients (10.5%). Mean duration of treatment with levetiracetam was 4.1 months. Doses ranged from 125 to 750 mg twice daily. Sixteen patients (84.2%) reported no side effects on levetiracetam. One patient experienced asthenia/somnolence and dizziness, and irritable, hyperactive, and hostile behavior led to discontinuation of levetiracetam in another patient. A third patient experienced irritability and moodiness that attenuated after 1 month of treatment and did not require discontinuation.

Conclusions.—In this small retrospective review, levetiracetam was found to be generally well tolerated and appears to be a promising candidate for additional evaluation in well‐controlled clinical trials of pediatric patients with migraine.