bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of SnO addition on optical absorption of bismuth borate glass and photocatalytic property of the crystallized glass
Authors: Masai Hirokazu , Fujiwara Takumi , Mori Hiroshi
Published: April 2008

We have found that an addition of SnO in a bismuth-borate glass, CaO–B2O3–Bi2O3–Al2O3–TiO2, decreases the optical absorption coefficient in the visible region, in which selective crystallization of TiO2 was observed after heat treatment. Since selective crystallization of TiO2 was also attained in the SnO-containing glass, the transparency of TiO2 crystallized glass can be improved independently of selective crystallization of TiO2. We have also demonstrated that the rutile-nanocrystallized glass with SnO addition shows a higher photocatalytic activity than the glass without SnO, indicating that this crystallized glass has a large potential for application as transparent photocatalytic materials.
Cr-substitution-induced ferroelectric and improved piezoelectric properties of Zn1−xCrxO films
Authors: Yang Y. C. , Song C. , Wang X. H. , Zeng F. , Pan F.
Published: April 2008

(0001) oriented polycrystalline Cr-doped ZnO films have been prepared on n-Si(111) single-crystal substrates by nonequilibrium reactive magnetron cosputtering. The c-axis texture of the films weakens and a transformation of doping mechanism from CrZn to CrZn+Cri is indicated as the doping concentration increases. The Cr dopants are demonstrated to exist as Cr3+ ions in the films. Ferroelectric measurements show that the Ag∕Zn0.94Cr0.06O∕n-Si heterostructure displays well-defined hysteresis loop with a remanent polarization ∼0.2μC∕cm2 and a coercive field ∼50kV∕cm at room temperature. The capacitance-voltage curves with clockwise traces show typical memory windows, which symmetrically widen as the sweep amplitude increases. Ferroelectricity in Cr-doped ZnO was also established by a displacement-voltage “butterfly” loop. The observed ferroelectric behavior is attributed to the partial replacement of host Zn2+ ions by smaller Cr3+ ions, which occupy off-center positions and thereby induce permanent electric dipoles. Moreover, electrical transport studies reveal that the conduction mechanism in Cr-doped ZnO is a combination of field-assisted ionic conduction and trap-controlled space-charge-limited conduction, which prevail in lower and higher voltage regions, respectively. A higher leakage occurs as the doping concentration increases, which may originate from a higher density of defects. Besides, a high piezoelectric d33 coefficient ∼120pm∕V is also achieved by Cr substitutions, which could make Cr-doped ZnO a promising material in piezoelectric devices.
Imaging interstitial iron concentrations in boron-doped crystalline silicon using photoluminescence
Authors: Macdonald D. , Tan J. , Trupke T.
Published: April 2008

Imaging the band-to-band photoluminescence of silicon wafers is known to provide rapid and high-resolution images of the carrier lifetime. Here, we show that such photoluminescence images, taken before and after dissociation of iron-boron pairs, allow an accurate image of the interstitial iron concentration across a boron-doped p-type silicon wafer to be generated. Such iron images can be obtained more rapidly than with existing point-by-point iron mapping techniques. However, because the technique is best used at moderate illumination intensities, it is important to adopt a generalized analysis that takes account of different injection levels across a wafer. The technique has been verified via measurement of a deliberately contaminated single-crystal silicon wafer with a range of known iron concentrations. It has also been applied to directionally solidified ingot-grown multicrystalline silicon wafers made for solar cell production, which contain a detectible amount of unwanted iron. The iron images on these wafers reveal internal gettering of iron to grain boundaries and dislocated regions during ingot growth.
High-bendability flexible dye-sensitized solar cell with a nanoparticle-modified ZnO-nanowire electrode
Authors: Jiang C. Y. , Sun X. W. , Tan K. W. , Lo G. Q. , Kyaw A. K. K. , Kwong D. L.
Published: April 2008

We report a high-bendability flexible dye-sensitized solar cell (DSSC) based on a ZnO-nanowire photoelectrode, which was fabricated on polyethylene terephtalate/indium tin oxide substrate by low-temperature hydrothermal growth. Nanowire morphology shows preferable in crack resistance due to its efficient release of bending stress. The ZnO-nanowire film can be bended to an extreme radius of 2mm with no crack observed. Flexible DSSCs based on this kind of ZnO-nanowire photoelectrodes showed good bending stability. With a ZnO-nanoparticle modification on the nanowires, the flexible DSSC fabricated showed a much improved power conversion efficiency. Meanwhile, the good bendablility of this nanoparticle-modified nanowire electrode is maintained. The results demonstrate that high quality ZnO nanowires fabricated by the low-temperature method is promising for efficient and flexible plastic solar cells.
An integrated method to determine melting temperatures in high-pressure laser-heating experiments
Authors: Benedetti Laura Robin , Antonangeli Daniele , Farber Daniel L. , Mezouar Mohamed
Published: April 2008

We present an integrated approach for the determination of melting in the laser-heated diamond-anvil cell by simultaneously monitoring several criteria. We combine x-ray diffraction based observations with detection of discontinuities in optical properties by spectroradiometric measurements. This approach increases the confidence of melt identification, especially with low-Z samples. We demonstrate the efficacy of the method with observations of melt in oxygen at 47GPa (1500K) and at 55GPa (1850K).
Are there stable long-range ordered Fe1−xCrx compounds?
Authors: Erhart Paul , Sadigh Babak , Caro Alfredo
Published: April 2008

The heat of formation of Fe–Cr alloys undergoes an anomalous change of sign at small Cr concentrations. This observation raises the question as to whether there are intermetallic phases present in this composition range. Here, we report the discovery of several long-range ordered structures that represent ground state phases at 0K. In particular, we have identified a structure at 3.7% Cr with an embedding energy which is 49meV∕Cr atom below the solid solution. This implies that there is an effective long-range attractive interaction between Cr atoms. We propose that the structures found in this study complete the low temperature–low Cr region of the phase diagram.
Content of carotenoids at different ripening stages in processing tomato in relation to soil water availability
Authors: Riggi Ezio , Patanè Cristina , Ruberto Giuseppe
Published: April 2008

The influence of 2 water regimes (a fully irrigated treatment receiving 100% of evapotranspiration for the whole growing season and an unirrigated control watered up to plant establishment only) on lycopene and β-carotene accumulation during fruit ripening in a field-grown processing tomato was studied. Since a strong effect of irrigation treatments on fruit water content was expected, carotenoid content on both a fresh and dry matter basis was studied. Regardless of ripening stage and adopted parameter unit (fresh or dry matter), higher amounts of lycopene were measured in the well watered treatment. Positive and no effects of water stress were reported on β-carotene content when expressed, respectively, on a fresh and dry weight basis. Both experimental factors influenced the β-carotene/lycopene ratio mostly in the first 2 ripening stages and there is evidence to suggest that, under soil water deficit conditions, the carotenoid biosynthetic pathway is more ‘β-carotene accumulation’ oriented, especially at the beginning of the fruit ripening process.
Appropriateness of adopting both a fresh and dry basis calculation, in order to better evaluate the role of water stress on carotenoid content, is emphasised. The possibility of reducing the irrigation water supply without drastically decreasing the studied fruit quality characteristics is suggested.
Association between pig activity and environmental factors in pig confinement buildings
Authors: Kim Ki Youn , Ko Han Jong , Kim Hyeon Tae , Kim Chi Nyon , Byeon Sang Hoon
Published: April 2008

The aim of this study was to determine the aerial contaminants affecting pig activity and evaluate the correlation between pig activity and aerial contaminants in a pig confinement building. This experiment was performed in a confinement growing and finishing room, and the data presented in this article was collected over a period of 50 days, with sampling every 2 days from June to September 2003. Air samples were taken in the middle of empty pens on both sides of the pig confinement building. In this study, we demonstrated statistically significant negative relationships between pig activity and temperature, relative humidity and ammonia, while total dust positively regressed with pig activity. Based on these experimental results, we reasoned that increases in temperature, hydrogen sulfide and ammonia in the pig building suppressed pig activity and that high levels of total dust in the pig building was attributable to increases in pig activity. The exposure limit values of aerial contaminants, such as particulate matter, gaseous compounds and airborne microorganisms related to the pigs’ health should be established in order to promote the performance and welfare of the pigs.
Sensory Phenomena in Experimental Nerve Block
Authors: Sinclair D. C. , Hinshaw J. R.
Published: April 2008

In the course of a series of blocks of the ulnar and lateral popliteal nerves of volunteers a study was made of the manner in which the responses of the subject to sensory stimulation become progressively altered and finally obliterated. These changes are described, together with the manner of recovery, and an account is given of various sensations induced by the blocking and the recovery processes. The relevant literature is briefly reviewed and possible factors involved in these phenomena are discussed.
Some Factors Affecting Response in Recognition Tests
Authors: Belbin Eunice , Cane Violet R.
Published: April 2008

Experiments were designed to investigate some of the factors which might affect a subject's responses in a recognition test. Two experiments are described. In the first, subjects were shown 12 similar photographs. They were then given a recognition test of 12 photographs, of which a number varying from o to 12 had been shown in the original display. All the photographs were sufficiently alike to render some guessing essential. It was found that subjects tended to select approximately 50 per cent. as having been seen previously and to reject 50 per cent. When a second and similar display and recognition test followed immediately, there was a tendency for subjects to make more “yes” responses, without any improvement in accuracy. The effect of giving serial presentation first was to increase the number accepted not only in that test but also in a test using simultaneous presentation which succeeded it. It was also shown that when a correct decision was possible but difficult a positively correct response (in this case recognizing something seen before) was easier than a negatively correct one (rejecting something not seen before).

In the second experiment subjects were shown a picture and were then asked to describe it from memory. Immediately afterwards half the group was given a multiple-choice recognition test while the other half was given a single-choice recognition test. It was found that accuracy and certainty of decision varied with the nature of the choice situation. The results are discussed in relation to a theory of adaptation levels.
“Handedness” and Skill
Authors: Provins K. A.
Published: April 2008

The variability of handedness with different tasks is discussed. Experiments are described which show under what conditions handedness becomes evident. Tasks involving three different levels of complexity were used. The simplest task measured the accuracy with which a particular pressure could be reproduced in isometric contraction of the flexors of the index finger on each side in 21 female subjects. In the second situation, the maximum speed of making an attempted tapping movement under the same conditions, was measured in ten of the same subjects using the same muscle group alternating with its antagonists. The same ten subjects were also tested on an aiming task which provided the third level of complexity. The results suggest that differences in performance between the two sides only occur where “timing” or the serial organization of muscle activity is required and that such differences may be due to training.

Whether handedness is inherited or acquired is briefly discussed, and a second series of experiments using the same tasks as before were carried out on one female and nine male subjects. In this instance, the first two tests were used on the big toe of each side as well as the index finger. The results confirm that differences in performance between the two sides on these tasks can be adequately explained in terms of usage or training.

The hypothesis that “timing” is therefore important in the learning of any movement where serial muscle contractions arc involved was tested and confirmed in a third experimental series. The consistency of timing of the application of force in turning a crank handle at maximum speed was measured in five male subjects before and after training. The implications of the results are discussed in relation to other researches on skills.
The Fusion Frequency of Flicker in the Central and Peripheral Field with Photopic Levels of Surround Luminance
Authors: Ettlinger George
Published: April 2008

Flicker-fusion frequencies have been measured against a photopic level of surround luminance in the four quadrants of the visual field and the critical fusion frequences (c.f.f.s.) taken in direct vision compared with those determined at 15° and 35° in the periphery. The central c.f.f.s. of 47 subjects exceeded the peripheral values only in just over half of all the quadrants tested, although smaller differential thresholds were given almost without exception in the centre than in the periphery by the same observers and under similar conditions on a test of brightness discrimination. Likewise higher central than peripheral c.f.f.s. were recorded in the great majority of all quadrants when determinations were made against a dark surround. The contrasting types of flicker response observed against the photopic ground were shown to be relatively reproducible, and the same pattern was as a rule found in at least three quadrants of any one visual field. It was ascertained that the different patterns might result from a reciprocal shift of fusion frequencies either in central or peripheral vision.

Interpretations of the higher peripheral c.f.f.s which adduce the effect of accentuated pupillary constriction with central stimulation mere contra-indicated since such patterns of flicker perception survive after the photopupillary reflex has been abolished. Some evidence was, however, forthcoming for the view that peripheral fusion frequencies tend to exceed central values when the test object is larger than about 1·5° in angular size and more intense than the surround. It was suggested that the contrasting types of flicker response might be related to individual differences in the effect that stimulus size has on the flicker pattern.
The Effect of Lack of Sleep on Visual Watch-Keeping
Authors: Wilkinson R. T.
Published: April 2008

Sixteen subjects performed a test of visual watch-keeping twice, at the same hour of the same day of successive weeks. The test lasted 40 min. On one of these occasions the test was done after normal sleep the previous night; signals were detected at a steady rate throughout. On the other occasion the subjects had no sleep the previous night; they passed the time in innocuous leisure activities. Here a similar level of performance was maintained for the first 20 min. of the test. After this the rate of signal detection declined steadily. In the final quarter of the test the rate was roughly one third that of the first quarter.

Signals missed were divided into three categories, ( a) signals missed while watching the display, ( b) signals missed while not watching, and, ( c) signals missed while asleep. Lack of sleep produced increases in all three of these categories.

These results support previous suggestions that a test has to be prolonged before performance is affected by moderate loss of sleep; they also suggest that it is the simpler, or perhaps the more predictable, tests which are more affected.
On the Failure to Eliminate Hypotheses in a Conceptual Task
Authors: Wason P. C.
Published: April 2008

This investigation examines the extent to which intelligent young adults seek (i) confirming evidence alone (enumerative induction) or (ii) confirming and discontinuing evidence (eliminative induction), in order to draw conclusions in a simple conceptual task. The experiment is designed so that use of confirming evidence alone will almost certainly lead to erroneous conclusions because (i) the correct concept is entailed by many more obvious ones, and (ii) the universe of possible instances (numbers) is infinite.

Six out of 29 subjects reached the correct conclusion without previous incorrect ones, 13 reached one incorrect conclusion, nine reached two or more incorrect conclusions, and one reached no conclusion. The results showed that those subjects, who reached two or more incorrect conclusions, were unable, or unwilling to test their hypotheses. The implications are discussed in relation to scientific thinking.
Beoadbent's Filter Theory: Postulate H and the Problem of Switching Time
Authors: Moray Neville
Published: April 2008

Groups of digits were presented binaurally and dichotically to subjects who were asked to recall them. Different rates and patterns of presentation were used, the design being based on that of Broadbent (1954). Broadbent's findings in this field were confirmed. If subjects are presented with simultaneous pairs of digits at a rate of 2 pairs per second dichotically, they cannot recall them if they are asked to alternate between the ears. If however the presentation is staggered, so that although the rate is constant the signals do not overlap, subjects can recall alternately from the two ears. It is suggested that these findings are better interpreted as an interference effect, not a rate effect. Criticism is offered of similar designs to measure “switching rate”. Criticism is also offered of Broadbent's estimate of “perception time” in such experiments. An analysis of the quantity and type of errors made by subjects is given, which suggests that Broad-bent's theory of a short term store on the peripheral side of a selective filter is in need of revision.
Discrimination of Small Shapes by the Rat
Authors: Dodwell P. C.
Published: April 2008

Three experiments on small shape discrimination are described. The first investigates the discrimination of square from circle, a discrimination claimed by Lashley to be extremely difficult for the rat and which has since become a matter of theoretical interest. The second and third test a prediction from the writer's theory of shape recognition; the prediction is refuted.
Role of the somatostatin system in contextual fear memory and hippocampal synaptic plasticity
Authors: Kluge Christian , Stoppel Christian , Szinyei Csaba , Stork Oliver , Pape Hans-Christian
Published: April 2008

Somatostatin has been implicated in various cognitive and emotional functions, but its precise role is still poorly understood. Here, we have made use of mice with somatostatin deficiency, based upon genetic invalidation or pharmacologically induced depletion, and Pavlovian fear conditioning in order to address the contribution of the somatostatin system to associative fear memory. The results demonstrate an impairment of foreground and background contextual but not tone fear conditioning in mice with targeted ablation of the somatostatin gene. These deficits were associated with a decrease in long-term potentiation in the CA1 area of the hippocampus. Both the behavioral and the electrophysiological phenotypes were mimicked in wild-type mice through application of the somatostatin-depleting substance cysteamine prior to fear training, whereas no further deficits were observed upon application in the somatostatin null mutants. These results suggest that the somatostatin system plays a critical role in the acquisition of contextual fear memory, but not tone fear learning, and further highlights the role of hippocampal synaptic plasticity for information processing concerning contextual information.
Differential roles for hippocampal areas CA1 and CA3 in the contextual encoding and retrieval of extinguished fear
Authors: Ji Jinzhao , Maren Stephen
Published: April 2008

Recent studies demonstrate that context-specific memory retrieval after extinction requires the hippocampus. However, the contribution of hippocampal subfields to the context-dependent expression of extinction is not known. In the present experiments, we examined the roles of areas CA1 and CA3 of the dorsal hippocampus in the context specificity of extinction. After pairing an auditory conditional stimulus (CS) with an aversive footshock (unconditional stimulus or US), rats received extinction sessions in which the CS was presented without the US. In Experiment 1, pretraining neurotoxic lesions in either CA1 or CA3 eliminated the context dependence of extinguished fear. In Experiment 2, lesions of CA1 or CA3 were made after extinction training. In this case, only CA1 lesions impaired the context dependence of extinction. Collectively, these results reveal that both hippocampal areas CA1 and CA3 contribute to the acquisition of context-dependent extinction, but that only area CA1 is required for contextual memory retrieval.
Gαi2 inhibition of adenylate cyclase regulates presynaptic activity and unmasks cGMP-dependent long-term depression at Schaffer collateral-CA1 hippocampal synapses
Authors: Bailey Christopher P. , Nicholls Russell E. , Zhang Xiao-lei , Zhou Zhen-yu , Müller Wolfgang , Kandel Eric R. , Stanton Patric K.
Published: April 2008

Cyclic AMP signaling plays a central role in regulating activity at a number of synapses in the brain. We showed previously that pairing activation of receptors that inhibit adenylate cyclase (AC) and reduce the concentration of cyclic AMP, with elevation of the concentration of cyclic GMP is sufficient to elicit a presynaptically expressed form of LTD at Schaffer collateral-CA1 synapses in the hippocampus. To directly test the role of AC inhibition and G-protein signaling in LTD at these synapses, we utilized transgenic mice that express a mutant, constitutively active inhibitory G protein, Gαi2, in principal neurons of the forebrain. Transgene expression of Gαi2 markedly enhanced LTD and impaired late-phase LTP at Schaffer collateral synapses, with no associated differences in input/output relations, paired-pulse facilitation, or NMDA receptor-gated conductances. When paired with application of a type V phosphodiesterase inhibitor to elevate the concentration of intracellular cyclic GMP, constitutively active Gαi2 expression converted the transient depression normally caused by this treatment to an LTD that persisted after the drug was washed out. Moreover, this effect could be mimicked in control slices by pairing type V phosphodiesterase inhibitor application with application of a PKA inhibitor. Electrophysiological recordings of spontaneous excitatory postsynaptic currents and two-photon visualization of vesicular release using FM1-43 revealed that constitutively active Gαi2 tonically reduced basal release probability from the rapidly recycling vesicle pool of Schaffer collateral terminals. Our findings support the hypothesis that inhibitory G-protein signaling acts presynaptically to regulate release, and, when paired with elevations in the concentration of cyclic GMP, converts a transient cyclic GMP-induced depression into a long-lasting decrease in release.
Pollination networks and functional specialization: a test using Lesser Antillean plant–hummingbird assemblages
Authors: Dalsgaard Bo , Martín González Ana M. , Olesen Jens M. , Timmermann Allan , Andersen Laila H. , Ollerton Jeff
Published: April 2008

Network analysis has in recent years improved our understanding of pollination systems. However, there is very little information about how functionally specialized plants and pollinators interact directly and indirectly in pollination networks. We have developed a parameter, Functional specialization index, to quantify functional specialization in pollination networks. Using this parameter, we examined whether different sized hummingbirds visit a distinct set of flowers in five hummingbird‐pollinated plant assemblages from the Lesser Antilles, obtaining a simple relationship between hummingbird body size, network parameter and ecological function. In the Lesser Antilles, functionally specialized hummingbird pollination is distinct for plant species pollinated by the largest hummingbird species, whereas the pollination niche gradually integrates with the insect pollinator community as hummingbird body size decreases. The network approach applied in this study can be used to validate functional specialization and community‐level interdependence between plants and pollinators, and it is therefore useful for evaluating and predicting plant resilience to pollinator loss, presently a global concern.
Ectoparasite community structure on three closely related seabird hosts: a multiscale approach combining ecological and genetic data
Authors: Gómez‐Díaz Elena , Navarro Joan , González‐Solís Jacob
Published: April 2008

Parasite communities can be structured at different spatial scales depending on the level of organization of the hosts; hence, examining this structure should be a multiscale process. We investigated ectoparasite community structure in three closely related seabird hosts, the Mediterranean Cory's shearwaterCalonectris diomedea diomedea, the Atlantic Cory's shearwaterC. d. borealisand the Cape Verde shearwaterC. edwardsii. This community was composed of three lice (Halipeurus abnormis,Austromenopon echinatumandSaemundssonia peusi)and one flea species (Xenopsylla gratiosa), and was considered at the infra‐, component and regional community levels. We examined temporal and spatial structuring of the infracommunities, the influence of host aggregation and body condition on the component community, and the effect of genetic and geographic connectivity among host populations on the regional community. Ectoparasite infracommunities showed substantial species overlaps in temporal patterns of abundance, but species were spatially segregated within the host body. Within component communities, all ectoparasite species showed an aggregated distribution in abundance. However, aggregation patterns and their relationships with the spatial distribution of hosts within the breeding colony differed among ectoparasite species, mainly reflecting ecological differences between fleas and lice. At the regional scale, similarity in ectoparasite communities correlated with geographic distances among host colonies, but not with genetic distances. This result suggests differences in climate and habitat characteristics among host localities as a major determinant of regional communities, rather than host connectivity. Taken together, our results highlight the importance of the geographic distribution of host breeding colonies and the spatial segregation within the host body as key factors in determining ectoparasite community structure inCalonectrisshearwaters.
A unified index to measure ecological diversity and species rarity
Authors: Mendes Renio S. , Evangelista Luiz R. , Thomaz Sidinei M. , Agostinho Angelo A. , Gomes Luiz C.
Published: April 2008

Several indices have been created to measure diversity, and the most frequently used are the Shannon‐Wiener (H) and Simpson (D) indices along with the number of species (S) and evenness (E). Controversies about which index should be used are common in literature. However, a generalized entropy (Tsallis entropy) has the potential to solve part of these problems. Here we explore a family of diversity indices (Sq; where q is the Tsallis index) and evenness (Eq), based on Tsallis entropy that incorporates the most used indices. It approaches S when q=0, H when q→1 and gives D when q=2. In general, varying the value of the Tsallis index (q), Sqvaries from emphasis on species richness (q<1) to emphasis on dominance (q>1). Similarly, Eqalso works as a tool to investigate diversity. In particular, for a given community, its minimum value represents the maximum deviation from homogeneity (Eq=1) for a particular q (herein named q*). It is remarkable that our analysis indicates that q* and its corresponding evenness, Eq*, are negatively affected by S when using simulated data. They may represent an index related to species rarity. Furthermore, Sq*(i.e. the value of Sqfor a specific q*) is positively affected by richness that is an important property of any diversity index. In general, our findings indicate that the indices H, D, S, Sq*, E and Eq*are only part of a whole set of possibilities. In addition, the ecological properties of Eq*and Sq*, proposed here for the first time, show promise in ecology.
Child Domestic Labour: A Modern Form of Slavery
Authors: Blagbrough Jonathan
Published: April 2008

This article provides a global scene for the scope of child domestic labour and explores the inter‐woven relationship between the practice and slavery, as well as the consequences for this uniquely vulnerable group of child workers. In doing so, it seeks to dispel the myths that child domestic work is a safe form of employment for girls (particularly those living with their employers), and that the practice offers any significant benefits for the majority of the children concerned. However, practitioners must avoid demonising employers if they are to assist child domestic workers (CDWs) more effectively, and should facilitate the empowerment of CDWs to protect themselves. Fundamentally, major changes are needed in societal attitudes which promote the continuance of the practice. For the sake of clarity, children and young persons under 18 years who are the subject of this study are referred to as ‘CDWs’ and the work they do as ‘child domestic labour’ (or occasionally as ‘domestic service’). The word ‘her’ in this study is shorthand for ‘his and her’ and is used because the large majority of CDWs are female.
‘Precious Children in a Heartless World’? The Complexities of Child Trafficking in Marseille
Authors: Oude Breuil Brenda Carina
Published: April 2008

This article examines how implicit notions in the concepts of ‘children’ and ‘home’ influence the study of child trafficking. Where children and adults are often presented as oppositional categories, home is regarded as territorialised, essentialised and unchangeable. These social constructions oversimplify trafficked and migrating children’s experiences, which is illustrated by three cases from the context of Marseille. They suggest that children’s agency may be better accounted for if we move from a focus on them being forcefully torn away from the safe place of home, to children’s strategies of placing themselves, continuously, in changing, hierarchical social settings.
Does alcohol increase the risk of overdose death: the need for a translational approach
Authors: Hickman Matt , Lingford‐Hughes Anne , Bailey Chris , Macleod John , Nutt David , Henderson Graeme
Published: April 2008

Background We argue for a translational approach to addiction science, using an important current research question as a case study.

Case study What is the evidence in support of the hypothesis that alcohol increases the risk of a heroin/opiate overdose through a pharmacological interaction?

Findings The positive epidemiological evidence shows that opiate overdose deaths rarely involve a single drug; that alcohol is the most common other drug involved; that there is a negative association between alcohol and morphine concentration at post mortem; and that post‐mortem levels of morphine are often below the levels expected of highly tolerant individuals. The evidence is consistent with the hypothesis that heroin users who drink may require less heroin to overdose than those who do not drink (all other factors being equal) because of a pharmacological interaction. However, the evidence is consistent with, and does not rule out, other causal (and non‐causal) pathways. Alcohol could be associated negatively with tolerance, or confounded by other factors. Experimental evidence is required which is unlikely to be obtained through further epidemiological study or through randomized clinical trials.

Conclusions We believe that animal models could provide the key evidence to test the hypothesis for a ‘pharmacodynamic’ or ‘pharmacokinetic’ interaction, which could be corroborated in clinical challenge studies and epidemiological studies. Such a translational approach demands greater collaboration between addiction scientists from basic to applied science and from neuroscience to social science, and would be able to address other key research questions and hypotheses in addiction.
High density genome‐wide DNA profiling reveals a remarkably stable profile in hairy cell leukaemia
Authors: Forconi Francesco , Poretti Giulia , Kwee Ivo , Sozzi Elisa , Rossi Davide , Rancoita Paola M. V. , Capello Daniela , Rinaldi Andrea , Zucca Emanuele , Raspadori Donatella , Spina Valeria , Lauria Francesco , Gaidano Gianluca , Bertoni Francesco
Published: April 2008

Hairy cell leukaemia (HCL) is a rare B‐cell neoplasm for which the molecular mechanisms are largely unknown. High‐density genome‐wide DNA profiling was performed with Affymetrix 250K arrays to analyse copy number (CN) changes and loss of heterozygosity (LOH) in 16 cases of HCL. Four of 16 cases (25%) demonstrated gross non‐recurrent CN deletions. Within the affected regions, we identified genes involved in bone marrow fibrosis (FGF12) and response to treatment (TP53) in individual cases. Large regions (>5 Mb) of LOH without any concomitant DNA CN changes were identified in 5/16 (31%) HCL and were indicative of uniparental disomy UD. The germline origin of UD was demonstrated in one case for which a matched normal sample was available. Overall analysis of LOH showed that identical loci were recurrently targeted in chromosomes 1, 2 and 6. As a whole, however, HCL showed a remarkably stable genome. This finding adds to several other features that are unique to HCL among mature B‐cell tumours.
Creative connections: parenting capacity, reading with children and practitioner assessment and intervention
Authors: Seden Janet
Published: April 2008

This paper presents some findings from a study of the views of 33 parents from a diversity of backgrounds with children between 0 and 12. Twenty‐two parents were using family support services. They were asked about their views on ‘parenting capacity’ based on the dimensions of The Framework for the Assessment of Children in Need and Their Families (Department of Health et al.) which are now incorporated into the Common Assessment Framework used in Every Child Matters (Department for Education and Skills). They were also asked about reading with their children and how this enhanced their parenting capacities. Their responses were analysed using the parenting capacity dimensions of The Framework for the Assessment of Children in Need and Their Families. It became apparent that this common activity (parent/child reading) contributed much to children's development and to the quality of the child/parent relationship. It also enhanced parenting capacity as described in the parenting capacity dimensions. This paper presents that part of the findings which illustrates the creative connections that exist between the activity of parents and children reading together and the parenting capacity dimensions social workers use in assessment and intervention. These findings are relevant to practitioners working within current policy and practice agendas in children's services, which promote multidisciplinary working and non‐stigmatizing assessments and interventions.
Molecular cloning and developmental expression of the vitellogenin gene in the endoparasitoid, Pteromalus puparum
Authors: Ye G.‐Y. , Dong S.‐Z. , Song Q.‐S. , Shi M. , Chen X.‐X. , Hu C.
Published: April 2008

A cDNA of the vitellogenin (Vg) protein gene was isolated from the endoparasitoid Pteromalus puparum and characterized. The putative coding sequence was found to be 5634 bp long, encoding 1803 amino acids in a single open reading frame. The chemically determined N‐terminal amino acid sequence of vitellin completely matched the deduced amino acid sequence that follows a putative signal peptide of 17 amino acid residues. The Vg mRNA was detected in the fat body of late female pupae, whereas the ovary and male fat body lacked the Vg transcript. The Vg mRNA level in the fat body depended significantly on the developmental stage, reaching the highest level 0 h after eclosion. The haemolymph Vg titre appeared 24 h after the appearance of Vg transcript. A positive correlation between the titre and transcript level of Vg in individual female wasps was found.
Input ‐ output devices: some ways forward
Authors: McDougall A.
Published: April 2008

In spite of technological advances, the QWERTY typewriter keyboard still predominates as the person‐computer interface. Some reasons are first given, then the later sections of the paper discuss other devices that are increasingly used in commerce and industry but which, as yet, have had little educational impact. The argument is for support for research and development of these devices in educational contexts, and this could be particularly beneficial for learners with special needs.
Computer graphics as a memory aid and a thinking ald
Authors: Phillips R. J.
Published: April 2008

Abstract The increasing use of microcomputers in classrooms opens up new possibilities for using visual, diagrammatic methods of teaching. This article sets out to explain why we sometimes abandon words and turn to graphical methods of communication. It is argued that a well designed graphical display can function as a kind of memory store. This view of the graphical display as a memory aid and a thinking aid suggests three principles for the program designer: parsimony, accessibility and reflection. ‘Progressive graphics’, where a display changes in step with the users' thinking, seem particularly suited to implementation on a computer.
The evaluation of microcomputer programs: an area of debate
Authors: Johnston V. M.
Published: April 2008

Abstract  The successful introduction of microcomputers into the curriculum is crucially dependent on software quality. Evaluations of programs must be based on educational rather than technological criteria. The available literature concerning software evaluation is reviewed, identified as classroom based studies, teacher training in software selection, issues in the design and development of programs as teaching material, and predictive evaluation through criterion checklists. Key areas of concern for software evaluation are identified as program description, external performance, structure of program, educational usefulness and documentation. Analysis of the knowledge and skills involved in program use, relating to both the cognitive and the affective, is suggested.
Social interaction and learning using micro‐PROLOG
Authors: Colbourn C. J. , Light P. H.
Published: April 2008

Abstract  Recent out‐of‐classroom studies have shown that interaction between children can facilitate correct solution of problem solving tasks, and that the benefits of interactive experience can carry over to subsequent individual post‐tests. These results have also been demonstrated in the context of schoolchildren's microcomputer use, although with caveats that may have more to do with the tasks than the medium. The present study investigated peer interaction in a more naturalistic classroom‐like context. Groups of children, with access to different levels of microcomputer resource, were given an introduction to using micro‐PROLOG.
Factors affecting microcomputer use and programming ability of secondary school children
Authors: Mohamedali M. H. , Messer D. J. , Fletcher B. (C).
Published: April 2008

Abstract  A survey was conducted in Hertfordshire to provide information about microcomputer use both in school and at home. All schools were found to possess microcomputers but only a limited number of pupils reported using the machines. The extent and type of use was found to be affected by gender, access to a home computer, experience, and competence. The survey included a measure of programming competence and factors that influenced this were investigated. Able programmers were frequently found to be male and to have access to home computers.
Students' approaches and attitudes to solving computer presented problems
Authors: Thompson D. G. , Jolly B. , Macdonald M. M. , Cookson J. , Holman J. , Keech T.
Published: April 2008

Abstract  The ‘diseases oriented’ approach to teaching medicine was used as a basis for computer presented problems to first and second year clinical students. Performance on one of the problems was analysed retrospectively to compare students who had attended innovatory Problem Based Learning (PBL) tutorials with those who experienced only the computer presentations. Results suggest that after such tutorial experience, students reached diagnoses quicker, displayed less rigid history taking, and were more responsive to the information they gathered.
Consumer participation in the development of modular computing in‐service training: a case study
Authors: Mallatratt J.
Published: April 2008

Abstract Technological and curricular developments place great demands upon school teachers and need to be underpinned by appropriate in‐service training (INSET). The introduction of a new funding mechanism for INSET (Grant‐related in‐service training — GRIST) seems, inter alia, to recognize a role for class‐room practitioners in the identification of specific training needs. The paper describes how one institution (Lancashire Polytechnic) has involved teachers and lecturers in INSET course development in the domain of Computing. This has been an attempt to more finely tune courses to meet their in‐service training needs. Consideration is given to the product(s) of these efforts.
Effects of experience on microcomputer use in primary schools: results of a second survey
Authors: Jackson A. (C.) , Fletcher B. (C.) , Messer D.
Published: April 2008

Abstract Following an initial survey of microcomputer use in Hertfordshire primary schools, a second, follow‐up survey was conducted two years later to examine how experience had changed attitudes and use. This second survey provided detailed information of microcomputer provision, classroom use, and an analysis of factors which were related to use. As before, the survey was in two parts: an initial questionnaire to collect information from both headteachers and teachers. Some changes were observed across surveys which suggested that teachers would make more innovative use of the microcomputer in the future given sufficient training. As before, children's access was limited, and they mostly used drill and practice‐type software in small groups (although child‐directed programs were becoming a little more popular). Both surveys indicated that microcomputers offered a focus for cooperative activity which had not been predicted. Interestingly, the type of software mainly used was found to be related to children's cooperative behaviour, and their motivation for work.
Matching tasks to children: can computers help?
Authors: Scrimshaw P.
Published: April 2008

Abstract  One of the most important tasks in teaching is the choice of suitable learning tasks for different children. This paper summarizes the results of one piece of research on this, analyses what is involved in matching tasks to children, and outlines some ways in which CAL packages might be used to improve matching.
Teaching PROLOG programming in the secondary school
Authors: Cope P.
Published: April 2008

Abstract A PROLOG programming course was trialed on a class of twelve 16–17 year‐old pupils who had varied previous experience of computing. The pupils were studying a variety of other subjects but would normally be considered to be of a high level of ability. The course was taught over a period of 15 weeks and lasted approximately 60 hours. Concepts covered included recursion and list processing. Most pupils were able to become reasonably competent over this period and one or two excelled. Previous experience of programming appeared to be an advantage if it had involved formal instruction in structured programming but indications were that self‐taught BASIC proved to be an obstacle. It was concluded that further investigation of PROLOG as a school programming language would be worthwhile.
A CAL experiment in a developing country
Authors: Mancey A.
Published: April 2008

Abstract Many experiments have been carried out to evaluate the effectiveness of CAL but almost exclusively in the developed world. The study described below was a controlled experiment designed to assess the effectiveness of two science simulation programs in the context of the developing country where computers were a rarity. Thirty‐six students of high ability used the simulations under controlled conditions and were then tested on the same topics. Control groups were given homework assignments on the same topics. The results showed positive effect sizes of about 0.2 for both simulations. Positive effect sizes were also obtained in a retention test given 3 months later. The results did not achieve statistical significance but significant interactions were found. Interviews indicated that the students had found the experience enjoyable and felt it beneficial.
The implications of the national curriculum for the use of information technology in the primary school
Authors: Blease D.
Published: April 2008

Abstract The purpose of this paper is to examine the Information Technology requirements of the National Curriculum in English, Mathematics, Science and Design and Technology as they apply to key stages 1 and 2 (5 –11‐year‐olds), and to suggest the minimum knowledge and skills required by primary school teachers in order to meet the statutory requirements of the 1988 Education Reform Act.
An approach to integrating educational software into the curriculum
Authors: Zehavi N. , Bruckheimer M.
Published: April 2008

Abstract  A scheme for teacher involvement in exploring the use of mathematical software was designed to meet practical needs of effective implementation. The scheme consists of observation of students at work, followed by didactical and cognitive workshops, in which teachers reflect on the implications of their observations for further classroom activities. The details of the scheme are described via an actual algebra software implementation in Grade 8. Observation of students working on the software and an informal evaluation of their achievement as related to the learning goals, led to professional teacher development toward adaptive implementation of the software for individual students.
Impacts of courseware and student characteristics on learning achievement: results of an empirical study
Authors: Karrer U.
Published: April 2008

Abstract Literature reviews revealed that not enough is known about specific software design and use features which contribute to learning effectiveness. Moreover, most research on these topics is carried out only in universities. Therefore, it was decided to conduct an empirical study with students of secondary schools, level two in Switzerland. Five classes and three pieces of courseware material were included in the study to investigate whether and how courseware and student characteristics have an impact upon the learning effectiveness.