bluuebunny/crossref_metadata_2025 huggingface dataset:
NK and NKT Cell-Independent Contribution of Interleukin-15 to Innate Protection against Mucosal Viral Infection
Authors: Gill Navkiran , Rosenthal Kenneth L. , Ashkar Ali A.
Published: March 2005

Interleukin-15 (IL-15) is essential for the development, maturation, and function of NK and NKT cells, which are critical components of the innate immune defense against viral infections. We recently showed that mice lacking IL-15 and/or NK/NKT cells are significantly more susceptible to intravaginal (IVAG) herpes simplex virus type 2 (HSV-2) infection than control mice. For this study, we examined whether IL-15 has any direct antiviral activity, independent of NK/NKT cells, in innate protection against HSV-2 infection. A sensitive enzyme-linked immunosorbent assay for murine IL-15 was developed and used to show that IVAG HSV-2 infection induces IL-15 in vaginal washes. Using immunohistochemistry, we detected IL-15-positive cells in the submucosa and vaginal epithelium following IVAG HSV-2 infection. Local, but not systemic, delivery of murine recombinant IL-15 (mrIL-15) to the genital mucosae of IL-15−/−and RAG-2−/−γc−/−mice, which both lack NK and NKT cells, resulted in significant reductions in HSV-2 titers in genital washes and 60% survival following IVAG HSV-2 challenge. Furthermore, we showed that IL-15 is important for CpG oligodeoxynucleotide (ODN)-induced innate protection against genital HSV-2 infection. While 100% of CpG ODN-treated RAG2−/−γc−/−mice, which are capable of producing IL-15 but lack NK/NKT cells, survived an IVAG HSV-2 challenge, only 60% of CpG ODN-treated IL-15−/−mice survived, and all of these mice had similar vaginal viral titers to those in control mice by day 3 postchallenge. Lastly, a treatment of RAW264.7 cells with mrIL-15 induced the production of tumor necrosis factor alpha and beta interferon (IFN-β), but not IFN-α, and significantly protected them against HSV-2 infection in vitro. The results of these studies indicate that IL-15 can act independently of NK/NKT cells in mediating the innate defense against viral infection.
X-ray powder diffraction data of (25R)-spirost-5-en-3β-ol(diosgenin)
Authors: Poveda J. C. , Henao J. A. , Delgado W. , de Correa R. Segura , López A. A.
Published: March 2005

The diosgenin, (25R)-spirost-5-en-3β-ol, was isolated from rhizomes of dioscorea meridensis and characterized by X-ray powder diffraction, IR and MS. The diosgenin was found to be monoclinic, with refined unit cell parameters a=16.774(3), b=7.259(2), c=10.383(2) Å, β=92.74(2)°, V=1262.9(3) (Å3), Z=2, Dx(g∕cm−3)1.089, with space group P21 (No. 4).
Synthesis and structure of the ternary nitride Li6WN4
Authors: Yuan W. X. , Hu J. W. , Song Y. T. , Wang W. J. , Xu Y. P.
Published: March 2005

The ternary nitridotungstate Li6WN4 has been synthesized via the solid state reaction of lithium subnitride, Li3N, with W under nitrogen. High quality X-ray powder diffraction data were collected for the crystal-structure determination. Li6WN4 crystallizes in the tetragonal system, space group P42∕nmc, with cell parameters a=6.6759(3) Å and c=4.9280(3) Å, Z=2. Preliminary thermal stability measurements of Li6WN4 show that it is sensitive to moisture, even at room temperature, and decomposes at high temperatures below 1000 °C under flowing nitrogen.
Influence of Racial Disparities in Procedure Use on Functional Status Outcomes Among Patients With Coronary Artery Disease
Authors: Kaul Padma , Lytle Barbara L. , Spertus John A. , DeLong Elizabeth R. , Peterson Eric D.
Published: March 2005

Background—

Although black cardiac patients receive fewer revascularization procedures than whites, it is unclear whether this has a detrimental impact on outcomes. The objective of our study was to compare 6-month functional status and angina outcomes among blacks and whites with documented coronary disease and to assess whether differential use of revascularization procedures affects these outcomes.

Methods and Results—

We identified a prospective cohort of 1534 white and 337 black patients undergoing cardiac catheterization between August 1998 and April 2001. Health status was assessed at baseline and 6 months with the Short-Form 36 (SF-36) Health Survey and the Seattle Angina Questionnaire (SAQ) Angina Frequency Scale. Compared with whites, blacks received fewer coronary revascularization procedures (52.5% versus 66.0%;
P
<0.01). By 6 months, blacks had similar mortality (odds ratio, 1.03; 95% CI, 0.57 to 1.9) but worse scores in 5 SF-36 domains (physical, social, role physical, role emotional, and mental health function). Blacks also reported higher rates of angina at 6 months than whites (34.2% versus 24.6%;
P
<0.01). After adjustment for baseline functional status and clinical and demographic variables, blacks had significantly worse summary physical component scores, summary mental component scores, and SAQ Angina Frequency Scale scores. However, differences in physical component summary scores and SAQ scores between blacks and whites were no longer significant after adjustment for revascularization status.

Conclusions—

Our study is among the first to document greater symptoms and functional impairment among black cardiac patients relative to whites. Differential use of coronary revascularization may contribute to the poorer functional outcomes observed among black patients with documented coronary disease.
Prevalence, Persistence, and Clinical Significance of Masked Hypertension in Youth
Authors: Lurbe Empar , Torro Isabel , Alvarez Vicente , Nawrot Tim , Paya Rafael , Redon Josep , Staessen Jan A.
Published: March 2005

Masked hypertension, an elevated daytime ambulatory blood pressure in the presence of a normal office blood pressure, confers an increased cardiovascular risk to adults. We investigated the prevalence, persistence, and clinical significance of masked hypertension in children and adolescents. We enrolled 592 youths (6 to 18 years old). Youths with masked hypertension (n=34) and a random sample of the normotensive participants (n=200) were followed-up. In a nested case-control study, we compared echocardiographic left ventricular mass among cases with persistent masked hypertension and normotensive controls. At baseline, mean age was 10.2 years; 535 youths were normotensive on office and daytime ambulatory blood pressure measurement (90.4%), and 45 had masked hypertension (7.6%). Compared with normotensive controls, participants with masked hypertension had a higher ambulatory pulse rate, were more obese, and were 2.5-times more likely to have a parental history of hypertension. Among 34 patients with masked hypertension (median follow-up 37 months), 18 became normotensive, 13 had persistent masked hypertension, and 3 had sustained hypertension. Patients with persistent masked hypertension (n=17) or who progressed from masked to sustained hypertension (n=3) had a higher left ventricular mass index (34.9 versus 29.6 g/m
2.7
;
P
=0.023) and a higher percentage with left ventricular mass index above the 95th percentile (30% versus 0%;
P
=0.014) than normotensive controls. In children and adolescents, masked hypertension is a precursor of sustained hypertension and left ventricular hypertrophy. This condition warrants follow-up and, once it becomes persistent, is an indication for blood pressure-lowering treatment.
Overlap in the Functional Neural Systems Involved in Semantic and Episodic Memory Retrieval
Authors: Rajah M. N. , McIntosh A. R.
Published: March 2005

Neuroimaging and neuropsychological data suggest that episodic and semantic memory may be mediated by distinct neural systems [Cabeza, R., & Nyberg, L. Imaging cognition II: An empirical review of 275 PET and fMRI studies. Journal of Cognitive Neuroscience, 12, 1–47, 2000; Gabrieli, J. D. Disorders of memory in humans. Current Opinion in Neurology and Neurosurgery, 6, 93–97, 1993; Gabrieli, J. D. Cognitive neuroscience of human memory. Annual Review of Psychology, 49, 87–115, 1998; Squire, L. R. The organization and neural substrates of human memory. International Journal of Neurology, 21–22, 218–222, 1987; Squire, L. R., & Zola, S. M. Structure and function of declarative and nondeclarative memory systems. Proceedings of the National Academy of Sciences, U.S.A., 93, 13515–13522, 1996; Tulving, E. Multiple memory systems and consciousness. Human Neurobiology, 6, 67–80, 1987]. However, an alternative perspective is that episodic and semantic memory represent different modes of processing within a single declarative memory system. To examine whether the multiple or the unitary system view better represents the data we conducted a network analysis using multivariate partial least squares (PLS) activation analysis followed by covariance structural equation modeling (SEM) of positron emission tomography data obtained while healthy adults performed episodic and semantic verbal retrieval tasks [Duzel, E., Cabeza, R., Picton, T. W., Yonelinas, A. P., Heinze, H. J., Scheich, H., & Tulving, E. Task-related and item related processes in episodic and semantic retrieval: A combined PET and ERP study. Proceedings of the National Academy of Sciences, U.S.A., 96, 1794–1799, 1999]. It is argued that if performance of episodic and semantic retrieval tasks are mediated by different memory systems, then there should differences in both regional activations and interregional correlations related to each type of retrieval task, respectively. The PLS results identified brain regions that were differentially active during episodic retrieval versus semantic retrieval. Regions that showed maximal differences in regional activity between episodic retrieval tasks were used to construct separate functional models for episodic and semantic retrieval. Omnibus tests of these functional models failed to find a significant difference across tasks for both functional models. The pattern of path coefficients for the episodic retrieval model were not different across tasks, nor were the path coefficients for the semantic retrieval model. The SEM results suggest that the same memory network/system was engaged across tasks, given the similarities in path coefficients. Therefore, activation differences between episodic and semantic retrieval may reflect variation along a continuum of processing during task performance within the context of a single memory system.
Second Language Interferes with Word Production in Fluent Bilinguals: Brain Potential and Functional Imaging Evidence
Authors: Rodriguez-Fornells Antoni , Lugt Arie van der , Rotte Michael , Britti Belinda , Heinze Hans-Jochen , Münte Thomas F.
Published: March 2005

Bilingual individuals need effective mechanisms to prevent interference between their languages. Using event-related brain potentials (ERPs) and functional magnetic resonance imaging (fMRI), we present evidence for interference of phonological information from the nontarget language in German—Spanish bilinguals. A tacit picture-naming task was used in which bilinguals and monolinguals had to make speeded responses based on the first letter of the picture's name in the target language. In one condition, subjects were required to respond when the name began with a vowel and to withhold a response if it started with a consonant. Stimuli had been selected such that in half of the trials, the names in both languages necessitated the same response, whereas in the other half, responses were different for the two languages. For the bilinguals, the language in which the stimuli had to be named was changed after each block. Bilinguals showed phonological interference compared with monolingual performance, which was evident in their performance, ERPs, and fMRI patterns. Nonlanguage-specific brain areas such as the left middle prefrontal cortex were found to be crucial for the control of interference.
Right Hemisphere Activation of Joke-related Information: An Event-related Brain Potential Study
Authors: Coulson Seana , Wu Ying Choon
Published: March 2005

Two studies tested the hypothesis that the right hemisphere engages in relatively coarse semantic coding that aids high-level language tasks such as joke comprehension. Scalp-recorded event-related brain potentials (ERPs) were collected as healthy adults read probe words (CRAZY) preceded either by jokes or nonfunny controls (“Everyone had so much fun jumping into the swimming pool, we decided to put in a littlewater/platform”). Probes were related to the meaning of the jokes, but not the controls. In Experiment 1a, with central presentation, probes following jokes (related) elicited less negative ERPs 300–700 msec postonset (N400) than did probes following nonfunny controls (unrelated). This finding suggests related probes were primed by the jokes. In addition, unrelated probes elicited a larger anterior positivity 700– 900 msec than did related, as irrelevant stimuli impacted control processes invoked by task demands. In Experiment 1b, probes (CRAZY) were preceded only by sentence-final words from jokes (water) or controls (platform). No ERP effects were observed in Experiment 1b, suggesting the N400 priming effect and the anterior positivity observed in Experiment 1a reflect semantic activations at the discourse level. To assess hemispheric differences in semantic activations, in Experiment 2, ERPs were recorded as participants read probe words presented in their left and right visual fields (LVF and RVF, respectively). Probes elicited a smaller N400 component when preceded by jokes than controls. This N400 priming effect was larger with presentation to the LVF, suggesting joke-relevant information was more active in the right hemisphere. The anterior positivity was observed with RVF but not LVF presentation, suggesting an important role for the left hemisphere in controlled retrieval in language comprehension.
Time-Critical Rendering of Huge Ecosystems Using Discrete and Continuous Levels of Detail
Authors: Zach Christopher , Mantler Stephan , Karner Konrad
Published: March 2005

We present a novel level-of-detail selection method for real-time rendering, which works on hierarchies of discrete and continuous representations. We integrate smoothly represented, point-rendered objects with discrete polygonal geometry and demonstrate our approach in a terrain-flyover application. In this testing application the digital elevation model is augmented with forests in accordance with satellite data. The vegetation is rendered as a continuous sequence of splats generated from a procedural description. Further, we discuss enhancements to our basic method to improve its scalability.
Real-Time Animation of Complex Virtual Cloth with Physical Plausibility and Numerical Stability
Authors: Kang Young-Min , Cho Hwan-Gue
Published: March 2005

Numerical instability has been a major obstacle to real-time cloth animation. Although the implicit method can make the simulation stable, it is still impossible to generate interactive animation when the geometric model of the virtual cloth is complex enough to represent realistic details. In this paper, we propose efficient animation techniques for the real-time animation of complex deformable objects. The proposed method exploits the stability of the implicit integration in order to use sufficiently large time steps for real-time environments, and obtains the approximate solution with optimized computation and storage. Unlike previous methods for real-time cloth animation, any severe simplification of the problem itself has been avoided in order to produce realistic motions of complex models. In addition, the proposed method deals with instability caused by a force derivative. This problem has been avoided in the previous work with excessive approximation or additional manipulation. However, the technique in this paper avoids instability with a minimal approximation, and does not increase any computational or geometric complexity. The method can be successfully integrated in various real-time environments, such as PC games and VR systems.
From Wheels to Wings with Evolutionary Spiking Circuits
Authors: Floreano Dario , Zufferey Jean-Christophe , Nicoud Jean-Daniel
Published: March 2005

We give an overview of the EPFL indoor flying project, whose goal is to evolve neural controllers for autonomous, adaptive, indoor micro-flyers. Indoor flight is still a challenge because it requires miniaturization, energy efficiency, and control of nonlinear flight dynamics. This ongoing project consists of developing a flying, vision-based micro-robot, a bio-inspired controller composed of adaptive spiking neurons directly mapped into digital microcontrollers, and a method to evolve such a neural controller without human intervention. This article describes the motivation and methodology used to reach our goal as well as the results of a number of preliminary experiments on vision-based wheeled and flying robots.
Agency in Natural and Artificial Systems
Authors: Moreno Alvaro , Etxeberria Arantza
Published: March 2005

We analyze the conditions for agency in natural and artificial systems. In the case of basic (natural) autonomous systems, self-construction and activity in the environment are two aspects of the same organization, the distinction between which is entirely conceptual: their sensorimotor activities are metabolic, realized according to the same principles and through the same material transformations as those typical of internal processes (such as energy transduction). The two aspects begin to be distinguishable in a particular evolutionary trend, related to the size increase of some groups of organisms whose adaptive abilities depend on motility. Here a specialized system develops, which, in the sensorimotor aspect, is decoupled from the metabolic basis, although it remains dependent on it in the self-constructive aspect. This decoupling reveals a complexification of the organization. In the last section of the article this approach to natural agency is used to analyze artificial systems by posing two problems: whether it is possible to artificially build an organization similar to the natural, and whether this notion of agency can be grounded on different organizing principles.
Evolutionary Robotics: A New Scientific Tool for Studying Cognition
Authors: Harvey Inman , Paolo Ezequiel Di , Wood Rachel , Quinn Matt , Tuci Elio
Published: March 2005

We survey developments in artificial neural networks, in behavior-based robotics, and in evolutionary algorithms that set the stage for evolutionary robotics (ER) in the 1990s. We examine the motivations for using ER as a scientific tool for studying minimal models of cognition, with the advantage of being capable of generating integrated sensorimotor systems with minimal (or controllable) prejudices. These systems must act as a whole in close coupling with their environments, which is an essential aspect of real cognition that is often either bypassed or modeled poorly in other disciplines. We demonstrate with three example studies: homeostasis under visual inversion, the origins of learning, and the ontogenetic acquisition of entrainment.
Beyond the Flesh: Some Lessons from a Mole Cricket
Authors: Clark Andy
Published: March 2005

What do linguistic symbols do for minds like ours, and how (if at all) can basic embodied, dynamical, and situated approaches do justice to high-level human thought and reason? These two questions are best addressed together, since our answers to the first may inform the second. The key move in scaling up simple embodied cognitive science is, I argue, to take very seriously the potent role of human-built structures in transforming the spaces of human learning and reason. In particular, in this article I look at a range of cases involving what I dub surrogate situations. Here, we actively create restricted artificial environments that allow us to deploy basic perception-action-reason routines in the absence of their proper objects. Examples include the use of real-world models, diagrams, and other concrete external symbols to support dense looping interactions with a variety of stable external structures that stand in for the absent states of affairs. Language itself, I finally suggest, is the most potent and fundamental form of such surrogacy. Words are both cheap stand-ins for gross behavioral outcomes, and the concrete objects that structure new spaces for basic forms of learning and reason. A good hard look at surrogate situatedness thus turns the standard skeptical challenge on its head. But it raises important questions concerning what really matters about these new approaches, and it helps focus what I see as the major challenge for the future: how, in detail, to conceptualize the role of symbols (both internal and external) in dynamical cognitive processes.
Close Encounters: Some Preliminary Observations on the Transmission of Impurity in Early Sunnī Jurisprudence
Authors: Maghen Ze'ev
Published: March 2005

The Prophet said, al-tahāra shatr al-īmān, "purity is half of faith." In this essay, I attempt to elucidate what appears to be a uniquely Islamic approach to the acquisition and impartation of ritually pollutive states. Based on a survey of relevant hadīth exempla and fiqh discussions—including sections dealing with saliva as a premier conductor of pollution, janāba (sexually induced impurity), menstruation, mulāmasa (contact with the opposite sex), and the question of water already used in ablutions—I argue that the sharī'a accords all human beings a clean ritual slate from birth, and, what is more surprising, flatly denies the possibility of persons becoming ceremonially contaminated or contributing to the ritual defilement of others under any circumstances. These characteristics make the Islamic tahāra system an intriguing anomaly in the world of religious purity codes.
Swimming and jumping in a semi-aquatic frog
Authors: Nauwelaerts Sandra , Stamhuis Eize , Aerts Peter
Published: March 2005

Locomotion has a clear ecological relevance for many animals. As animals need to move in order to escape from predators, find food, defend territories, etc., it is expected that locomotor performance might affect an individual's survival and reproduction. Clear links have also been found between an animal's performance and its morphology. A function analysis can unravel the underlying mechanistic facets of this link.Frogs are interesting model species because they add an extra element to this topic; they have to perform in two entirely different physical environments, particularly semi-aquatic species. However, no trade-off was found between jumping and swimming performance. Morphological correlates were found but, to understand causations, a thorough understanding of the mechanics of locomotion is required.When comparing the mechanics of jumping and swimming, the question arises of how to ensure a sound comparison. Ideally, some measure of 'effort' has to be added to the analysis. We suggest the use of the propulsive impulse. Unexpectedly, the impulse of swimming proved to be significantly smaller than the jumping impulses during locomotion in a semi-aquatic frog, Rana esculenta, even when maximal performance had been induced in both media.To verify our impulse calculations, we analysed the external forces during both locomotor modes. The forces during terrestrial locomotion can be measured directly using a force plate; determining the forces in water requires a more complex set-up. For that reason, we performed a DPIV (Digital Particle Image Velocimetry) analysis on the flow generated by swimming frogs. These experiments confirmed the results of our impulse calculations.
A Modeling Study of Summertime East Pacific Wind-Induced Ocean–Atmosphere Exchange in the Intraseasonal Oscillation
Authors: Maloney Eric D. , Esbensen Steven K.
Published: March 2005

Intraseasonal precipitation variability over the northeast Pacific warm pool during June–October in the National Center for Atmospheric Research Community Atmosphere Model 2.0.1 with a relaxed Arakawa–Schubert convection parameterization is found to be strongly sensitive to wind-induced variations in surface latent heat flux. A control simulation with interactive surface fluxes produces northeast Pacific warm pool intraseasonal wind and precipitation variations that are of similar magnitude and structure to those associated with the observed intraseasonal oscillation (ISO). Periods of low-level westerly intraseasonal wind anomalies are associated with enhanced surface latent heat fluxes and enhanced precipitation, as in observations. Variations in surface wind speed primarily control the surface flux anomalies.

A simulation in which eastern North Pacific oceanic latent heat fluxes are fixed produces intraseasonal precipitation variations that are significantly weaker than those in the control simulation and in observations. These results support the observational findings of Maloney and Esbensen, who suggested that wind-induced latent heat flux variability is a significant driver of ISO-related convective variability over the northeast Pacific warm pool during Northern Hemisphere summer. East Pacific ISO-related convection in this model, thus, appears to be forced by an analogous wind-induced surface heat exchange mechanism to that proposed by Maloney and Sobel to explain the forcing of west Pacific ISO-related convection. The surface exchange mechanism is apparently active within regions of mean westerly low-level flow.

In contrast, summertime eastern North Pacific intraseasonal wind variance and spatial structure does not differ significantly between the control and fixed-evaporation simulations. A strong coupling between the east Pacific flow and precipitation over Central America may be responsible for the relatively small changes in wind variability between the simulations. Interactions among the coarsely resolved Central American orography, the large-scale flow, and the convection parameterization in the model likely contribute to this anomalous coupling.
A simplified high-throughput method for pyrethroid knock-down resistance (kdr) detection in Anopheles gambiae
Authors: Lynd Amy , Ranson Hilary , McCall P J , Randle Nadine P , Black William C , Walker Edward D , Donnelly Martin J
Published: March 2005

Background

A single base pair mutation in the sodium channel confers knock-down resistance to pyrethroids in many insect species. Its occurrence in Anopheles mosquitoes may have important implications for malaria vector control especially considering the current trend for large scale pyrethroid-treated bednet programmes. Screening Anopheles gambiae populations for the kdr mutation has become one of the mainstays of programmes that monitor the development of insecticide resistance. The screening is commonly performed using a multiplex Polymerase Chain Reaction (PCR) which, since it is reliant on a single nucleotide polymorphism, can be unreliable. Here we present a reliable and potentially high throughput method for screening An. gambiae for the kdr mutation.

Methods

A Hot Ligation Oligonucleotide Assay (HOLA) was developed to detect both the East and West African kdr alleles in the homozygous and heterozygous states, and was optimized for use in low-tech developing world laboratories. Results from the HOLA were compared to results from the multiplex PCR for field and laboratory mosquito specimens to provide verification of the robustness and sensitivity of the technique.

Results and Discussion

The HOLA assay, developed for detection of the kdr mutation, gives a bright blue colouration for a positive result whilst negative reactions remain colourless. The results are apparent within a few minutes of adding the final substrate and can be scored by eye. Heterozygotes are scored when a sample gives a positive reaction to the susceptible probe and the kdr probe. The technique uses only basic laboratory equipment and skills and can be carried out by anyone familiar with the Enzyme-linked immunosorbent assay (ELISA) technique. A comparison to the multiplex PCR method showed that the HOLA assay was more reliable, and scoring of the plates was less ambiguous.

Conclusion

The method is capable of detecting both the East and West African kdr alleles in the homozygous and heterozygous states from fresh or dried material using several DNA extraction methods. It is more reliable than the traditional PCR method and may be more sensitive for the detection of heterozygotes. It is inexpensive, simple and relatively safe making it suitable for use in resource-poor countries.
Generalizability of writing scores: an application of structural equation modeling
Authors: Schoonen Rob
Published: March 2005

The assessment of writing ability is notoriously difficult. Different facets of the assessment seem to influence its outcome. Besides the writer’s writing proficiency, the topic of the assignment, the features or traits scored (e.g., content or language use) and even the way in which these traits are scored (e.g., holistically or analytically) may contribute to the writer’s score. In this article, the effect of these facets is estimated in a generalizability study using variance analytic techniques. A structural equation modeling (SEM) approach is used to estimate the variance components in the writing scores. Eighty-nine grade 6 students (aged 11-12 years) wrote four essays, each of which was scored by five raters using two scoring methods (i.e., holistically and analytically) for two traits (i.e., Content and Organization, and Language Use). Analyses of these ratings showed that the generalizability of writing scores and the effects of raters and topics are very much dependent on the way the essays are scored and the trait that is scored. The overall picture is that writing tasks contribute more to the score variance than raters do.
Self-assessment, preparation and response time on a computerized oral proficiency test
Authors: Malabonga Valerie , Kenyon Dorry M. , Carpenter Helen
Published: March 2005

Two studies investigated technical aspects of a computer-mediated test, the Computerized Oral proficiency Instrument (COPI), particularly in contrast to a similar tape-mediated test, the Simulated Oral proficiency Interview (SOPI). The first study investigated how examinees used self-assessment to choose an appropriate starting level on the COPI. The second study looked at examinees’ planning and response time on the COPI, and the factors that affected their use of time. Fifty-five university students took the COPI and SOPI in one of three languages: Arabic, Chinese, or Spanish. Results show that the majority of examinees (92%) were able to use the self-assessment instrument to select test tasks at appropriate difficulty levels. However, the COPI starting level (which was based on examinees’ self-assessment) might have been problematic for a small proportion (8%) of the examinees who appeared to choose tasks that were too difficult for them. As for planning and response time on the COPI, different amounts of time were used across four main levels of proficiency. Examinees with the highest proficiency levels tended to use less planning time but gave longer responses.
Peer assessment of language proficiency
Authors: Cheng Winnie , Warren Martin
Published: March 2005

This article describes part of an investigation into the reliability and potential benefits of incorporating peer assessment into English language programmes. Undergraduate Engineering students attending a university in Hong Kong were asked to assess the English language proficiency of their peers among other assessment criteria, such as preparation, content, organisation and delivery as exhibited in the seminar, oral presentation and written report of an integrated group project. The article compares the students’ attitudes towards assessing both the English language proficiency and other aspects of the performance of their peers. It also compares peer and teacher assessments. The findings suggest that students had a less positive attitude towards assessing their peers’ language proficiency, but they did not score their peers’ language proficiency very differently from the other assessment criteria. Students and teachers were different in their respective marking behaviours and the ways oral and written language proficiency were interpreted. While students derived benefits from the peer assessment exercise, a question mark hangs over incorporating peer assessment for both language proficiency and the other criteria into the regular assessment process until such differences are resolved. Suggestions are made for improvement in procedures and future research.
Assessment of readiness to change in patients with osteoarthritis. Development and application of a new questionnaire
Authors: Heuts Peter HTG , de Bie Rob A , Dijkstra Arie , Aretz Karin , Vlaeyen Johan WS , Schouten Hubert JA , Hopman-Rock Marijke , van Weel Chris , van Schayck Constant P
Published: March 2005

Objective: To develop a self-report measure for assessment of the stage of change in patients with osteoarthritis, in order to identify patients who would benefit from a self-management programme.

Methods: According to the ‘stages of change’ model a questionnaire was developed with three groups of items corresponding to the precontemplation stage (Pre), the contemplation (Cont) and the action (Act) stage. Internal consistency and factor structure of this questionnaire were investigated by assessing Cronbach's alphas and by performing factor analysis.

Subjects and setting: The questionnaire was offered to 273 patients who entered a randomized clinical trial on self-management in a general health care setting.

Results: Factor analysis revealed that most items corresponded to the a priori described groups, while some items were not loading on the presumed factor. In each subgroup some items were deleted, resulting in a 15-item questionnaire. After this item reduction Cronbach's alphas were 0.72 (Pre), 0.76 (Cont) and 0.79 (Act) and all factor loadings were satisfactory (above 0.35). Classification revealed some differences between parts of the total group, for example in the proportion of patients in the preparation stage (recruited by general practitioner 33.6%; advertisement 49.2%).

Conclusions: The Stages of Change Questionnaire in Osteoarthritis, a 15-item questionnaire to assess the ‘stage of change’ of a patient with osteoarthritis showed good internal consistency and adequate factor structure. These findings warrant further studies on validity and applicability in a clinical context.
Species difference in the disposition of acrylonitrile: quantitative whole-body autoradiographic study in rats and mice
Authors: Jacob Sam , Ahmed Ahmed E
Published: March 2005

Previous studies from this and other laboratories have indicated the role of species difference in acrylonitrile (VCN) toxicity and its metabolism to cyanide. Our recent studies also indicated a more pronounced elimination of VCN following oral as compared to i.v. administration. To further characterize the mechanism of these differences on the distribution of VCN, quantitative whole-body autoradiographic distribution and elimination studies were conducted at various time points (0.08, 8, 24, 48 h) following the administration of an equivalent i.v. dose of 2-[14C]-VCN to male Fischer rats and male CD-1 mice. Whole-body autoradiographs obtained from freeze-dried and acid-extracted sections of rats and mice demonstrated a rapid uptake of 14C in liver, lungs, spleen and bone marrow at early time intervals. Quantitatively, the uptake, retention and covalent interaction of 14C were higher in organs of rats as compared to mice, over 48 h. Mice eliminated 74% of the total administered dose of 2-[14C]-VCN (expired air 4%, urine 16% and feces 54%), while rats eliminated only 26% of the dose (expired air 2%, urine 4% and feces 20%). Species differences in VCN toxicity seem to be correlated with its rate of elimination. The distribution and elimination data demonstrated that mice divest VCN more rapidly than rats. The study also demonstrated that administration of VCN in rats resulted in covalent interactions and retention of 2-[14C]-VCN/metabolites in the tissues thus exerting more chronic toxicity to rats than to mice.
Prevalence and risk factors of occupational hand dermatoses in electronics workers
Authors: Shiao Judith Shu-Chu , Sheu Hamm-Ming , Chen Chiou-Jong , Tsai Perng-Jyh , Guo Yueliang Leon
Published: March 2005

The electronics industry is becoming an important mainstream in the workforce in some developed countries and in Taiwan. Among patients with occupational hand dermatitis in northern Taiwan, workers from electronics industries were one of the most important groups. We conducted a field investigation to determine the prevalence, patterns and risk factors of occupational hand dermatoses among electronics workers. The survey was conducted in five electronics plants using a self-administered questionnaire on skin symptoms and risk factors. Skin examination and patch testing were followed for those with symptoms compatible with hand dermatitis. A total of 3070 workers completed the questionnaire. Among them, 302 (9.8%) reported to have symptoms (itching and with either redness/scaling) compatible with contact dermatitis on hands. Hand dermatitis was associated with working in the fabrication unit and personal history of atopy and metal allergy, as well as the following job titles: wafer bonding, cutting, printing/photomasking, softening/degluing, impregnation and tin plating. Among those with reported hand dermatitis, 183 completed skin examination and patch testing, 65/183 (35.5%) were diagnosed as having irritant contact dermatitis (ICD) and 7/183 (3.8%) allergic contact dermatitis. The most important allergens were nickel, cobalt and phenylenediamine. In conclusion, Taiwanese electronics workers have a high risk of having hand dermatitis, especially ICD. Preventive efforts should be focused on the workers with risk factors or at certain worksites.
Gene-expression profiling using suppression-subtractive hybridization and cDNA microarray in rat mononuclear cells in response to welding-fume exposure
Authors: Rim Kyung Taek , Park Kun Koo , Sung Jae Hyuck , Chung Yong Hyun , Han Jeong Hee , Cho Key Seung , Kim Kwang Jong , Yu Il Je
Published: March 2005

Welders with radiographic pneumoconiosis abnormalities have shown a gradual clearing of the X-ray identified effects following removal from exposure. In some cases, the pulmonary fibrosis associated with welding fumes appears in a more severe form in welders. Accordingly, for the early detection of welding-fume-exposure-induced pulmonary fibrosis, the gene expression profiles of peripheral mononuclear cells from rats exposed to welding fumes were studied using suppression-subtractive hybridization (SSH) and a cDNA microarray. As such, Sprague-Dawley rats were exposed to a stainless steel arc welding fume for 2 h/day in an inhalation chamber with a 107.59 / 2.6 mg/m3 concentration of total suspended particulate (TSP) for 30 days. Thereafter, the total RNA was extracted from the peripheral blood mononuclear cells, the cDNA synthesized from the total RNA using the SMARTTM PCR cDNA method, and SSH performed to select the welding-fume-exposure-regulated genes. The cDNAs identified by the SSH were then cloned into a plasmid miniprep, sequenced and the sequences analysed using the NCBI BLAST programme. In the SSH cloned cDNA microarray analysis, five genes were found to increase their expression by 1.9-fold or more, including Rgs 14, which plays an important function in cellular signal transduction pathways; meanwhile 36 genes remained the same and 30 genes decreased their expression by more than 59%, including genes associated with the immune response, transcription factors and tyrosine kinases. Among the 5200 genes analysed, 256 genes (5.1%) were found to increase their gene expression, while 742 genes (15%) decreased their gene expression in response to the welding-fume exposure when tested using a commercial 5.0k DNA microarray. Therefore, unlike exposure to other toxic substances, prolonged welding-fume exposure was found to substantially downregulate many genes.
Morphological differentiation of Betula (birch) pollen in northwest North America and its palaeoecological application
Authors: Clegg Benjamin F. , Tinner Willy , Gavin Daniel G. , Hu Feng Sheng
Published: March 2005

Lake sediments from arcto-boreal regions commonly contain abundant Betula pollen. However, palaeoenvironmental interpretations of Betula pollen are often ambiguous because of the lack of reliable morphological features to distinguish among ecologically distinct Betula species in western North America. We measured the grain diameters and pore depths of pollen from three tree-birch species (B. papyrifera, B. kenaica and B. neoalaskana) and two shrub-birch species (B. glandulosa and B. nana), and calculated the ratio of grain diameter to pore depth (D/P ratio). No statistical difference exists in all three parameters between the shrub-birch species or between two of the tree-birch species (B. kenaica and B. papyrifera), and B. neoalaskana is intermediate between the shrub-birch and the other two tree-birch species. However, mean pore depth is significantly larger for the tree species than for the shrub species. In contrast, mean grain diameter cannot distinguish tree and shrub species. Mean D/P ratio separates tree and shrub species less clearly than pore depth, but this ratio can be used for verification. The threshold for distinguishing pollen of tree versus shrub birch lies at 2.55 μm and 8.30 for pore depth and D/P ratio, respectively. We'applied these thresholds to the analysis of Betula pollen in an Alaskan lake-sediment core spanning the past 800 years. Results show that shrub birch increased markedly at the expense of tree birch during the‘Little Ice Age’; this patten is not discernible in the profile of total birch pollen.
The Dahomey Gap: an abrupt climatically induced rain forest fragmentation in West Africa during the late Holocene
Authors: Salzmann Ulrich , Hoelzmann Philipp
Published: March 2005

The Dahomey Gap, a savanna corridor interrupting the zonal West African rain forest, did not exist during the mid-Holocene. The pollen diagram from Lac Sélé (7°9'N, 2°26'E) indicates that in southern Benin a semi-evergreen rainforest prevailed between c. 8400 and 4500 cal. yr BP. The mid-Holocene marine transgression caused a spread of mangrove forest along the inland lagoons. Pollen analysis and geochemistry indicate that the Dahomey Gap became established at the onset of the late Holocene due to an abrupt climatic change between c. 4500 and 3400 cal. yr BP. Drier climatic conditions led to a rapid deterioration of the rain forest and subsequent spread of Sudano-Guinean savannas. A return to wetter climatic conditions between c. 3300 and 1100 cal. yr BP resulted in a rise in the lake level and a renewed spread of forests into the savanna. During this time the Dahomey Gap consisted of a forest-savanna mosaic with a high number of pioneer tree taxa including the oil palm Elaeis guineensis After c. 1100 cal. yr BP the lake level dropped again and the Lac Sélé profile indicates drier environmental conditions resulting in the establishment of an open savanna which persists until present. The palaeorecord from Lac Sélé suggests that the role of humans in shaping the West African savannas has been overestimated. The opening of the Dahomey Gap and spread of the oil palm E. guineensis can now be confidentially attributed to climatic change and was not initiated by humans.
Minimum count sums for charcoal concentration estimates in pollen slides: accuracy and potential errors
Authors: Finsinger Walter , Tinner Willy
Published: March 2005

Charcoal particles in pollen slides are often abundant, and thus analysts are faced with the problem of setting the minimum counting sum as small as possible in order to save time. We analysed the reliability of charcoal-concentration estimates based on different counting sums, using simulated low-to high-count samples. Bootstrap simulations indicate that the variability of inferred charcoal concentrations increases progressively with decreasing sums. Below 200 items (i.e., the sum of charcoal particles and exotic marker grains), reconstructed fire incidence is either too high or too low. Statistical comparisons show that the means of bootstrap simulations stabilize after 200 counts. Moreover, a count of 200-300 items is sufficient to produce a charcoal-concentration estimate with less than+5% error if compared with high-count samples of 1000 items for charcoal/marker grain ratios 0.1-0.91. If, however, this ratio is extremely high or low (> 0.91 or < 0.1) and if such samples are frequent, we suggest that marker grains are reduced or added prior to new sample processing.
Mycophenolate mofetil and skin diseases
Authors: Hartmann M , Enk A
Published: March 2005

Mycophenolate mofetil (MMF) is an immunosuppressive drug the efficiency of which has been established in renal transplantation. Recent studies suggest that it may also be effective in the treatment of variant skin diseases especially if the skin lesions are triggered by lymphocytes. Studies have shown efficacy in autoimmune bullous dermatoses, atopic dermatitis and psoriasis. However, there are no placebo-controlled trials that support the use of MMF as first line therapy in these skin diseases.
An investigation of the cognitive processes underlying the keyword method of foreign vocabulary learning
Authors: Shapiro Amy M. , Waters Dusty L.
Published: March 2005

The Keyword Method (KWM) of vocabulary learning is a mnemonic method designed to help students learn foreign vocabulary. It has been shown to be effective over several other memorization strategies. The present experiment was designed to explore the cognition underlying the effectiveness of the KWM. Specifically, both the degree of cognitive engagement with the method and visual encoding were examined as possible sources. Subjects were tested in a 2 (imagery level)×2 (processing strategy) mixed design. Each subject was asked to memorize 30 Latin vocabulary words, divided evenly among high- and low-imagery value words. Subjects were either provided with both keywords and interactions (the Given condition) or instructions to generate their own keywords and interactions (the Self-Generated condition). Retention was tested in both immediate and delayed post-tests. Results revealed a strong effect of imagery level in both post-tests. No significant main effect of processing strategy or interactions between imagery and processing were observed in either post-test. Results indicate that the KWM is effective because it provides a meaningful visual image upon which to base memory for a new word’s meaning. They suggest that there is some flexibility in how the KWM is used.