bluuebunny/crossref_metadata_2025 huggingface dataset:
Phosphorylations of DEAD Box p68 RNA Helicase Are Associated with Cancer Development and Cell Proliferation
Authors: Yang Liuqing , Lin Chunru , Liu Zhi-Ren
Published: September 2005

The nuclear p68 RNA helicase is essential for normal cell growth. The protein plays a very important role in early organ development and maturation. In our previous report, we showed that recombinant p68 RNA helicase was phosphorylated at serine/threonine and tyrosine residue(s). In the present study, we examined the phosphorylation status of p68 in six different cancer cell lines and compared the results with those in cells derived from the corresponding normal tissues. We showed here that p68 was phosphorylated at tyrosine residue(s) in all tested cancer cells but not in the corresponding normal cells/tissues. The tyrosyl phosphorylation of p68 also responded to platelet-derived growth factor. It is thus clear that p68 phosphorylation at tyrosine residue(s) is associated with abnormal cell proliferation and cancer development. The tyrosyl phosphorylation(s) was diminished if the cancer cells were treated with apoptosis agents, such as tumor necrosis factor-α, tumor necrosis factor–related apoptosis-inducer ligand, and STI-571. The tyrosyl phosphorylation of p68, however, was not affected by other anticancer drugs, such as piceatannol, etoposide, and taxol. The close correlation between p68 phosphorylations and cancer may provide a useful diagnostic marker and potential therapeutic target for cancer treatment.
Common and Differential Neural Mechanisms Supporting Imitation of Meaningful and Meaningless Actions
Authors: Rumiati Raffaella I. , Weiss Peter H. , Tessari Alessia , Assmus Ann , Zilles Karl , Herzog Hans , Fink Gereon R.
Published: September 2005

Neuropsychological studies indicate that, after brain damage, the ability to imitate meaningful or meaningless actions can be selectively impaired. However, the neural bases supporting the imitation of these two types of action are still poorly understood. Using PET, we investigated in 10 healthy individuals the neural mechanisms of imitating novel, meaningless actions and familiar, meaningful actions. Data were analyzed using SPM99. During imitation, a significant positive correlation (p < .05, corrected) of regional cerebral blood flow with the amount of meaningful actions was observed in the left inferior temporal gyrus only. In contrast, a significant positive correlation (p < .05, corrected) with the amount of meaningless movements was observed in the right parieto-occipital junction. The direct categorical comparison of imitating meaningful (100%) relative to meaningless (100%) actions showed differential increases in neural activity (p < .001, uncorrected) in the left inferior temporal gyrus, the left parahippocampal gyrus, and the left angular gyrus. The reverse categorical comparison of imitating meaningless (100%) relative to meaningful (100%) actions revealed differential increases in neural activity (p < .001, uncorrected) in the superior parietal cortex bilaterally, in the right parieto-occipital junction, in the right occipital-temporal junction (MT, V5), and in the left superior temporal gyrus. Increased neural activity common to imitation of meaningless and meaningful actions compared to action observation was observed in a network of areas known to be involved in imitation of actions including the primary sensorimotor cortex, the supplementary motor area, and the ventral premotor cortex. These results are compatible with the two-route model of action imitation which suggests that there are at least two mechanisms involved in imitation of actions: a direct mechanism transforming a novel action into a motor output, and a semantic mechanism, on the basis of stored memories, that allows reproductions of known actions. Our results indicate that, in addition to shared neural processes, the direct and the semantic mechanisms that underlie action imitation also draw upon differential neural mechanisms. The direct mechanism underlying imitation of meaningless actions differentially involves visuospatial transformation processes as evidenced by activation of areas belonging to the dorsal stream. In contrast, imitation of meaningful actions differentially involves semantic processing as evidenced by activation of areas belonging to the ventral stream.
The Perception of Voice Onset Time: An fMRI Investigation of Phonetic Category Structure
Authors: Blumstein Sheila E. , Myers Emily B. , Rissman Jesse
Published: September 2005

This study explored the neural systems underlying the perception of phonetic category structure by investigating the perception of a voice onset time (VOT) continuum in a phonetic categorization task. Stimuli consisted of five synthetic speech stimuli which ranged in VOT from 0 msec ([da]) to 40 msec ([ta]). Results from 12 subjects showed that the neural system is sensitive to VOT differences of 10 msec and that details of phonetic category structure are retained throughout the phonetic processing stream. Both the left inferior frontal gyrus (IFG) and cingulate showed graded activation as a function of category membership with increasing activation as stimuli approached the phonetic category boundary. These results are consistent with the view that the left IFG is involved in phonetic decision processes, with the extent of activation influenced by increased resources devoted to resolving phonetic category membership and/or selecting between competing phonetic categories. Activation patterns in the cingulate suggest that it is sensitive to stimulus difficulty and resolving response conflict. In contrast, activation in the posterior left middle temporal gyrus and the left angular gyrus showed modulation of activation only to the “best fit” of the phonetic category, suggesting that these areas are involved in mapping sound structure to its phonetic representation. The superior temporal gyrus (STG) bilaterally showed weaker sensitivity to the differences in phonetic category structure, providing further evidence that the STG is involved in the early analysis of the sensory properties of speech.
Differential Effects of Lesions of the Amygdala and Prefrontal Cortex on Recognizing Facial Expressions of Complex Emotions
Authors: Shaw P. , Bramham J. , Lawrence E. J. , Morris R. , Baron-Cohen S. , David A. S.
Published: September 2005

Humans can detect facial expressions of both simple, basic emotions and expressions reflecting more complex states of mind. The latter includes emotional expressions that regulate social interactions (“social expressions” such as looking hostile or friendly) and expressions that reflect the inner thought state of others (“cognitive expressions” such as looking pensive). To explore the neural substrate of this skill, we examined performance on a test of detection of such complex expressions in patients with lesions of the temporal lobe (n = 54) or frontal lobe (n = 31). Of the temporal group, 18 had unilateral focal lesions of the amygdala and of the frontal group, 14 patients had unilateral lesions of the ventromedial prefrontal cortex-two regions held to be pivotal in mediating social cognitive skills. Damage to either the left or right amygdala was associated with impairment in the recognition of both social and cognitive expressions, despite an intact ability to extract information relating to invariant physical attributes. Lesions to all of the right prefrontal cortex-not just the ventromedial portions-led to a specific deficit in recognizing complex social expressions with a negative valence. The deficit in the group with right prefrontal cortical damage may contribute to the disturbances in social behavior associated with such lesions. The results also suggest that the amygdala has a role in processing a wide range of emotional expressions.
Structural Repair of Composite Structural Armor
Authors: Mahdi S. , Gama B. A. , Yarlagadda S. , Gillespie J. W.
Published: September 2005

Composite structural armor (CSA) is a multifunctional material that provides ballistic protection, stiffness, and strength at minimum weight. It consists of a multilayered architecture of polymer composites, rubber and ceramic tiles, stacked in a precise manner to obtain optimal performance. During its lifetime, CSA will experience manufacturing defects and be subjected from low to high velocity impact threats that will reduce the performance of the structure. The ability to repair a CSA is consequently an important factor in the future deployment of the CSA. The present study addresses the problem of the repair of CSA in a minimum number of steps. Several potential repair methods are introduced, and an adhesively bonded plug repair scheme is then further analyzed. Virgin (control) and repaired CSA beams are manufactured and their static behaviors are compared in a four-point bend test. The performance of a scarf patch repair is assessed. The effect of three scarf angles and two repair adhesive systems, one being low-temperature cure and the other room-temperature cure, are compared. The room-temperature cure repair system offers only a limited ability to bond to the different material layers, thereby limiting the performance of the repaired CSA. On the other hand, it is found that the low-temperature cure repair system provides sufficient interfacial strength to allow the repair to recover an appreciable amount of the original structural performance of the beams. Furthermore, it is found that the repair efficiency increases as the scarf angle decreases. This study clearly demonstrates that it is possible to repair the through-thickness section of CSA, in a single-step operation, and renew structural performance.
Reduction of ethanol intake by chronic treatment with Hypericum perforatum, alone or combined with naltrexone in rats
Authors: Perfumi Marina , Mattioli Laura , Cucculelli Marino , Massi Maurizio
Published: September 2005

Acute treatment with extracts of Hypericum perforatum, the common plant usually called St. John’s Wort, reduces voluntary ethanol intake in Marchigian Sardinian alcohol-preferring (msP) rats and acts synergistically with opioid receptor antagonists to further attenuate ethanol consumption. The present study evaluated the effect of chronic (once a day for 12 days) intragastric administration of a CO2 Hypericum perforatum extract (HPCO2), given alone or combined with naltrexone (NTX), on ethanol intake offered 2h/day in msP rats. Chronic treatment with HPCO2 markedly reduced ethanol intake at the dose of 125, but not at 7mg/kg; the effect of 125mg/kg was observed since the first day of treatment and remained constant across the 12 days. The same dose of HPCO2 slightly reduced the simultaneous intake of food only on day 3 and day 11 of treatment. Treated rats promptly recovered baseline ethanol intake when treatment did not precede access to ethanol (on day 8) or after the end of treatment (day 13 and day 14), suggesting that HPCO2 administrations did not induce conditioned aversion to alcohol. Chronic intraperitoneal treatment with NTX reduced ethanol intake at 3, but not at 0.5mg/kg. The synergistic effect on ethanol intake of HPCO2 and NTX was evident also in conditions of chronic treatment. HPCO2, 7mg/kg, and NTX, 0.5mg/kg, evoked a pronounced and statistically significant reduction of ethanol intake, while being inactive. The effect on ethanol intake of the combined treatment remained stable over the 12 days of treatment; food intake was slightly reduced only on day 3 and on day 7 in response to 125mg/kg of HPCO2 combined with NTX 0.5mg/kg, but no difference in body weight between controls and treated rats was observed at the end of treatment. Following 12-day treatment with 125mg/kg of HPCO2, no difference was observed in the responsivity of msP rats to the effect on ethanol intake of several doses of the extract. In conclusion, the present results provide evidence for a selective and pronounced effect of HPCO2, alone or combined with naltrexone, on ethanol intake in conditions of chronic treatment, without development of tolerance. These findings further support the view that clinical trials for extracts of Hypericum perforatum in the treatment of alcoholism should be considered.
Characterization of a 7% carbon dioxide (CO2) inhalation paradigm to evoke anxiety symptoms in healthy subjects
Authors: Poma Stefano Zanone , Milleri Stefano , Squassante Lisa , Nucci Gianluca , Bani Massimo , Perini Giulia I. , Merlo-Pich Emilio
Published: September 2005

The present study is aimed at characterizing the carbon dioxide (CO2) procedure in healthy subjects to achieve reliable provocation of anxiety symptoms.

Thirty healthy subjects inhaled in single-blind both compressed air and 7% CO2 mixture. Panic Symptom List (PSLIII-R), Visual Analogue Scale-Anxiety (VAS-A), State Anxiety Inventory (STAI-Y/1), respiratory parameters and skin conductance were measured. ‘Responders’ were classified depending on PSLIII-R scores after CO2. Twelve out of the 21 ‘responders’ performed a second test to assess test-retest repeatability.

In 21 subjects%VAS-A (45.4 32.1) and PSLIII-R (pre-test 2.3 2.1, post-test 17.5 8.2) but not STAI-Y/1, significantly increased during CO2 inhalation. Respiratory Rate, Minute Volume, end-Tidal CO2 and skin conductance rose in ‘responders’. Repeatability was studied with Bland-Altman plots, revealing mean difference between tests close to 0 for both%VAS-A and PSLIII-R. Among physiologic parameters, end-Tidal CO2 and Respiratory Rate showed good repeatability, with a within-subject CV of 9.2% and 6%, respectively.

The challenge produced measurable response in healthy subjects. Good test-retest repeatability was observed in ‘responders’. These data indicate that the test can be suitable for testing putative anti-panic or anxiolytic drugs in clinical studies using a within subject, crossover design.
Systematic review of randomized controlled trials of atypical antipsychotics and selective serotonin reuptake inhibitors for behavioural problems associated with pervasive developmental disorders
Authors: Dinca O. , Paul M. , Spencer N. J.
Published: September 2005

A systematic review of randomized controlled trials of the use of atypical antipsychotics and selective serotonin reuptake inhibitors in the treatment of behavioural problems associated with pervasive developmental disorders is reported. A search through both published and unpublished literature, including contacting drug companies and known experts in the field was undertaken. Six trials met the criteria for inclusion in the review. They largely suffer from methodological weaknesses; only two trials had satisfactory methodological quality. The heterogeneity in outcome measurements prevented from conducting a meta-analysis. There is yet no coherent body of data concerning the effects of these medications across all sub-classifications of pervasive developmental disorders, across all age categories, and concerning their medium- and long-term effects, and their effects on quality of life. Atypical antipsychotics and selective serotonin reuptake inhibitors may be of benefit for behavioural problems associated with pervasive developmental disorders. Risperidone has been the best studied among these medications. Atypical antipsychotics appear to have a low risk of extrapyramidal symptoms during short-term treatment. The reviewed trials cannot provide data on the use of selective serotonin reuptake inhibitors in the treatment of children with pervasive developmental disorders. No firm conclusions for clinical practice can be drawn. Larger, well-conducted randomized controlled trials with long-term follow-up are needed.
Fish and chips: Various methodologies demonstrate utility of a 16,006-gene salmonid microarray
Authors: von Schalburg Kristian R , Rise Matthew L , Cooper Glenn A , Brown Gordon D , Gibbs A Ross , Nelson Colleen C , Davidson William S , Koop Ben F
Published: September 2005

Background

We have developed and fabricated a salmonid microarray containing cDNAs representing 16,006 genes. The genes spotted on the array have been stringently selected from Atlantic salmon and rainbow trout expressed sequence tag (EST) databases. The EST databases presently contain over 300,000 sequences from over 175 salmonid cDNA libraries derived from a wide variety of tissues and different developmental stages. In order to evaluate the utility of the microarray, a number of hybridization techniques and screening methods have been developed and tested.

Results

We have analyzed and evaluated the utility of a microarray containing 16,006 (16K) salmonid cDNAs in a variety of potential experimental settings. We quantified the amount of transcriptome binding that occurred in cross-species, organ complexity and intraspecific variation hybridization studies. We also developed a methodology to rapidly identify and confirm the contents of a bacterial artificial chromosome (BAC) library containing Atlantic salmon genomic DNA.

Conclusion

We validate and demonstrate the usefulness of the 16K microarray over a wide range of teleosts, even for transcriptome targets from species distantly related to salmonids. We show the potential of the use of the microarray in a variety of experimental settings through hybridization studies that examine the binding of targets derived from different organs and tissues. Intraspecific variation in transcriptome expression is evaluated and discussed. Finally, BAC hybridizations are demonstrated as a rapid and accurate means to identify gene content.
Mycelium development in Streptomyces antibioticus ATCC11891 occurs in an orderly pattern which determines multiphase growth curves
Authors: Manteca Angel , Fernandez Marisol , Sanchez Jesus
Published: September 2005

Background

The current model for the developmental cycle ofStreptomycesconfluent cultures on agar surface is based on the assumption that the only differentiation takes place along the transverse axis (bottom-up): a vegetative (substrate) mycelium grows completely live and viable on the surface and inside the agar until it undergoes a death process and differentiates to a reproductive (aerial) mycelium which grows into the air. Hence, this vertical description assumes that the development in the pre-sporulating phases is more or less homogeneous in all zones of the plate surface.

Results

The work presents a detailed analysis of the differentiation cycle inStreptomyces antibioticusATCC11891 considering a different spatial dimension: the longitudinal axes, represented by the plate surface. A previously unsuspected complexity during the substrate mycelial phase was detected. We have demonstrated that the young substrate hyphae suffer an early death round that has not been previously described. Subsequently, the remaining mycelium grows in successive waves which vary according to the density of the spore inoculum. In the presence of dense inocula (1.5 × 106spores per plate), the hyphae develop in regular circles, approximately 0.5 cm in diameter. By contrast, with highly diluted inocula (6 × 103spores per plate), aerial mycelium develops initially in the form of islands measuring 0.9 mm in diameter. Further mycelial development occurs between the circles or islands until the plate surface is totally covered. This pattern persists throughout the entire developmental cycle including the sporulation phases.

Conclusion

An early death round during the substrate mycelial phase ofStreptomyces antibioticusATCC11891 takes place prior to successive growth periods in surface cultures. These developmental periods in turn, determine the shape of the complex multiphase growth curves observed. As shown here, these results also apply to otherStreptomycesstrains and species. Understanding these peculiarities of theStreptomycesdevelopmental cycle is essential in order to properly interpret the morphological/biochemical data obtained from solid cultures and will expand the number of potential phenotypes subject to study.
Protein secondary structure assignment revisited: a detailed analysis of different assignment methods
Authors: Martin Juliette , Letellier Guillaume , Marin Antoine , Taly Jean-François , de Brevern Alexandre G , Gibrat Jean-François
Published: September 2005

Background

A number of methods are now available to perform automatic assignment of periodic secondary structures from atomic coordinates, based on different characteristics of the secondary structures. In general these methods exhibit a broad consensus as to the location of most helix and strand core segments in protein structures. However the termini of the segments are often ill-defined and it is difficult to decide unambiguously which residues at the edge of the segments have to be included. In addition, there is a "twilight zone" where secondary structure segments depart significantly from the idealized models of Pauling and Corey. For these segments, one has to decide whether the observed structural variations are merely distorsions or whether they constitute a break in the secondary structure.

Methods

To address these problems, we have developed a method for secondary structure assignment, called KAKSI. Assignments made by KAKSI are compared with assignments given by DSSP, STRIDE, XTLSSTR, PSEA and SECSTR, as well as secondary structures found in PDB files, on 4 datasets (X-ray structures with different resolution range, NMR structures).

Results

A detailed comparison of KAKSI assignments with those of STRIDE and PSEA reveals that KAKSI assigns slightly longer helices and strands than STRIDE in case of one-to-one correspondence between the segments. However, KAKSI tends also to favor the assignment of several short helices when STRIDE and PSEA assign longer, kinked, helices. Helices assigned by KAKSI have geometrical characteristics close to those described in the PDB. They are more linear than helices assigned by other methods. The same tendency to split long segments is observed for strands, although less systematically. We present a number of cases of secondary structure assignments that illustrate this behavior.

Conclusion

Our method provides valuable assignments which favor the regularity of secondary structure segments.
A situational picture of HIV/AIDS and injection drug use in Vinnitsya, Ukraine
Authors: Barcal Katerina , Schumacher Joseph E , Dumchev Kostyantyn , Moroz Larisa Vasiliyevna
Published: September 2005

Background

New and explosive HIV epidemics are being witnessed in certain countries of Eastern Europe, including Ukraine, as well as a rapid and dramatic increase in the supply, use, and negative public health consequences of illicit drugs. A majority of registered HIV cases in Ukraine occur among injection drug users (IDUs), large numbers of whom report HIV risk behaviors such as needle sharing. The purpose of this study was to apply the World Health Organization's Rapid Assessment and Response on Injection Drug Use (IDU-RAR) guide to create a situational picture in the Vinnitsya Oblast, Ukraine, a region with very scarce information about the HIV/AIDS and injection drug use (IDU) epidemics.

Methods

The IDU-RAR uses a combination of qualitative data collection techniques commonly employed in social science and evaluation research to quickly depict the extent and nature of the given health problem and propose locally relevant recommendations for improvement. The investigators focused their assessment on the contextual factors, drug use, and intervention and policy components of the IDU-RAR. A combination of network and block sampling techniques was used. Data collection methods included direct observation, review of existing data, structured and unstructured interviews, and focus group discussions. Key informants and locations were visited until no new information was being generated.

Results

The number of registered HIV cases in Vinnitsya has increased from 3 (1987–1995) to 860 (1999–10/2004), 57 of whom have already died. Ten percent of annual admissions to the area's Regional Narcological Dispensary were for opiate disorders, and the number of registered IDUs rose by 20% from 1999 to 2000. The level of HIV/AIDS awareness is generally poor among the general population but high among high-risk populations. Both HIV/AIDS and injection drug use carry a strong stigma in the community, even among medical professionals. There was very little evidence of primary HIV/AIDS prevention efforts, and IDU prevention efforts focused on promotion of anti-drug messages in the schools.

Conclusion

Given that Ukraine has sparse resources to be devoted to this problem, action recommendations should be prioritized, realistic, and initially targeted to persons in greatest need. The following action recommendations are prioritized by the following categories: First priority: Voluntary Counseling and Testing; Second Priority: Prevention and Education; and Third Priority: Harm Reduction and Treatment. They are provided in this sequence based on what response can realistically be implemented first with limited additional resources and can make the greatest immediate impact. The persons at greatest risk, HIV positive persons and IDUs, should be attended to first.
Immunologic aspect of ovarian cancer and p53 as tumor antigen
Authors: Nijman HW , Lambeck A , van der Burg SH , van der Zee AGJ , Daemen T
Published: September 2005

Ovarian cancer represents the fifth leading cause of death from all cancers for women. During the last decades overall survival has improved due to the use of new chemotherapy schedules. Still, the majority of patients die of this disease. Research reveals that ovarian cancer patients exhibit significant immune responses against their tumor. In this review the knowledge obtained thus far on the interaction of ovarian cancer tumor cells and the immune system is discussed. Furthermore the role of p53 as tumor antigen and its potential role as target antigen in ovarian cancer is summarized. Based on the increased knowledge on the role of the immune system in ovarian cancer major improvements are to be expected of immunotherapy based treatment of this disease.
The HTLV-1 Tax protein binding domain of cyclin-dependent kinase 4 (CDK4) includes the regulatory PSTAIRE helix
Authors: Fraedrich Kirsten , Müller Birthe , Grassmann Ralph
Published: September 2005

Background

The Tax oncoprotein of human T-cell leukemia virus type 1 (HTLV-1) is leukemogenic in transgenic mice and induces permanent T-cell growthin vitro. It is found in active CDK holoenzyme complexes from adult T-cell leukemia-derived cultures and stimulates the G1- to-S phase transition by activating the cyclin-dependent kinase (CDK) CDK4. The Tax protein directly and specifically interacts with CDK4 and cyclin D2 and binding is required for enhanced CDK4 kinase activity. The protein-protein contact between Tax and the components of the cyclin D/CDK complexes increases the association of CDK4 and its positive regulatory subunit cyclin D and renders the complex resistant to p21CIPinhibition. Tax mutants affecting the N-terminus cannot bind cyclin D and CDK4.

Results

To analyze, whether the N-terminus of Tax is capable of CDK4-binding,in vitrobinding -, pull down -, and mammalian two-hybrid analyses were performed. These experiments revealed that a segment of 40 amino acids is sufficient to interact with CDK4 and cyclin D2. To define a Tax-binding domain and analyze how Tax influences the kinase activity, a series of CDK4 deletion mutants was tested. Different assays revealed two regions which upon deletion consistently result in reduced binding activity. These were isolated and subjected to mammalian two-hybrid analysis to test their potential to interact with the Tax N-terminus. These experiments concurrently revealed binding at the N- and C-terminus of CDK4. The N-terminal segment contains the PSTAIRE helix, which is known to control the access of substrate to the active cleft of CDK4 and thus the kinase activity.

Conclusion

Since the N- and C-terminus of CDK4 are neighboring in the predicted three-dimensional protein structure, it is conceivable that they comprise a single binding domain, which interacts with the Tax N-terminus.
Immunolocalization of RANKL is Increased and OPG Decreased During Dietary Magnesium Deficiency in the Rat
Authors: Rude Robert K , Gruber Helen E , Wei Livia Y , Frausto Angelica
Published: September 2005

Background

Epidemiological studies have linked low dietary magnesium (Mg) to low bone mineral density and osteoporosis. Mg deficiency in animal models has demonstrated a reduction in bone mass and increase in skeletal fragility. One major mechanism appears to be an increase in osteoclast number and bone resorption. The final pathway of osteoclastogenesis involves three constituents of a cytokine system: receptor activator of nuclear factor kB ligand (RANKL); its receptor, receptor activator of nuclear factor kB (RANK); and its soluble decoy receptor, osteoprotegerin (OPG). The relative presence of RANKL and OPG dictates osteoclastogenesis. The objective of this study was to assess the presence of RANKL and OPG in rats on a low Mg diet.

Methods

RANKL and OPG were assessed by immunocytochemistry staining in the tibia for up to 6 months in control rats on regular Mg intake (0.5 g/kg) and experimental rats on reduction of dietary Mg (.04%, 25% and 50% of this Nutrient Requirement).

Results

At all dietary Mg intakes, alteration in the presence of immunocytochemical staining of RANKL and OPG was observed. In general, OPG was decreased and RANKL increased, reflecting an alteration in the RANKL/OPG ratio toward increased osteoclastogenesis.

Conclusion

We have, for the first time demonstrated that a reduction in dietary Mg in the rat alters the presence of RANKL and OPG and may explain the increase in osteoclast number and decrease in bone mass in this animal model. As some of these dietary intake reductions in terms of the RDA are present in a large segment of or population, Mg deficiency may be another risk factor for osteoporosis.
OK, who’s got number one? Permeable Triadic Dialogue, covert participation and the co-construction of checking episodes
Authors: Gourlay Lesley
Published: September 2005

The three-part Initiation, Response, Follow-up (IRF) cycle, or Triadic Dialogue, has been shown to be a common pattern in classroom discourse, and is widely used in EFL classrooms. The value of Triadic Dialogue has been debated in general education, where it has attracted criticism for being over-formulaic and restrictive, although recent research has pointed to the range of functions that may be fulfilled by the follow-up move. But how do teachers and learners actually work within this pattern in the adult EFL context? This paper examines lesson extracts from two multilingual Business English lessons, focusing first on how the teachers embed a variety of language functions within Triadic Dialogue used in checking episodes. It then goes on to investigate how the students engage in a variety of covert individual and group activities during checking episodes. It concludes by arguing that Triadic Dialogue may be viewed as a ritualistic framework, with points of permeability where teachers can initiate embedded extensions and students can enact their own personal agendas. It also argues that the checking episode itself may be viewed as a hybrid, exhibiting multiple macro functions in the wider classroom discourse and process.
Slow muscle regulates the pattern of trunk neural crest migration in zebrafish
Authors: Honjo Yasuko , Eisen Judith S.
Published: September 2005

In avians and mice, trunk neural crest migration is restricted to the anterior half of each somite. Sclerotome has been shown to play an essential role in this restriction; the potential role of other somite components in specifying neural crest migration is currently unclear. By contrast, in zebrafish trunk neural crest, migration on the medial pathway is restricted to the middle of the medial surface of each somite. Sclerotome comprises only a minor part of zebrafish somites, and the pattern of neural crest migration is established before crest cells contact sclerotome cells, suggesting other somite components regulate the pattern of zebrafish neural crest migration. Here, we use mutants to investigate which components regulate the pattern of zebrafish trunk neural crest migration on the medial pathway. The pattern of trunk neural crest migration is aberrant in spadetail mutants that have very reduced somitic mesoderm, in no tail mutants injected with spadetail morpholino antisense oligonucleotides that entirely lack somitic mesoderm and in somite segmentation mutants that have normal somite components but disrupted segment borders. Fast muscle cells appear dispensable for patterning trunk neural crest migration. However, migration is abnormal in Hedgehog signaling mutants that lack slow muscle cells, providing evidence that slow muscle cells regulate the pattern of trunk neural crest migration. Consistent with this idea, surgical removal of adaxial cells, which are slow muscle precursors, results in abnormal patterning of neural crest migration;normal patterning can be restored by replacing the ablated adaxial cells with ones transplanted from wild-type embryos.
Vapor Pressure Measurements of LiI + C2H5OH Solutions
Authors: Safarov Javid T.
Published: September 2005

Vapor pressure p of LiI + C2H5OH solutions at T = (298.15 to 323.15) K were measured by the static method. The osmotic Φ and activity coefficients γ and activity of solvent a
s have been evaluated. The experiments were carried out in molality range m = (0.34523 to 8.61859) mol kg−1. The Antoine equation for the empiric description of experimental vapor pressure results and the Pitzer–Mayorga model with inclusion of Archer's ionic strength dependence of the third virial coefficient for the description of calculated osmotic coefficients were used. The parameters of Archer extended Pitzer model was used for evaluation of activity coefficients.
Characterization and drainage kinetics of colloidal gas aphrons
Authors: Bhatia Divesh , Goel Gaurav , Bhimania Sidhartha K. , Bhaskarwar Ashok N.
Published: September 2005

The variation of air holdup and stability of colloidal gas aphrons (CGAs) with stirring time, surfactant concentration [6, 8.1, 10, and 12 mM sodium lauryl sulfate (SLS)], and stirring speed (3500–7000 rpm) was investigated, and an empirical correlation between the air holdup and stirring time was obtained. A first‐order model for the drainage of CGAs was proposed and it correlated very well with the experimental data. A population balance model was proposed and correlated to the first‐order drainage model to obtain an expression for the size distribution of CGA bubbles. A narrower size distribution at large stirring times was observed, which was correlated to the stability of CGAs. The stabilization of CGA dispersion with attainment of equilibrium size distribution at longer stirring times, analogous to homogenization of emulsions, was observed and an empirical expression for this time was reported. Mixing of two oppositely charged CGAs, generated using SLS (anionic) and cetyl trimethyl ammonium bromide (CTAB) (cationic), showed no effect on their stability, air holdup, and drainage kinetics. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Measurement of flow in microfluidic networks with micrometer‐sized flow restrictors
Authors: Bao Jian‐Bin , Jed Harrison D.
Published: September 2005

The fluid dynamics in micrometer‐sized flow restrictors was evaluated, to test the predictions of the Hagen–Poiseuille equation in small microchip devices. A photobleaching, time‐of‐flight linear flow rate measurement method was developed for the evaluation of flow in slot‐shaped channels with at least one dimension in the size range of 1–3 μm. For a linear flow rate range in the narrowest dimension of 0.3 to 16 mm/s (volumetric flow rates of 0.6 to 32 nL/s, maximum Reynolds number of 0.3), observed flow rates agreed with theoretical predictions within experimental error (2–3%). An empirical equation for the geometric form factor of a D‐shaped channel was developed, providing a useful working curve for use of the Hagen–Poiseuille equation in microfluidics design. The Hagen–Poiseuille solution can be used to design multiport devices with intersecting flow channel networks, achieving the intended flow rate ratios in channels with differing flow resistance with an accuracy of 1–2%. Despite the differences between achieved etched dimensions and the nominal design values a deviation of only 1–4% in the flow ratios was also achieved. This observation provides a useful guideline for predicting tolerance sensitivity in device manufacture. © 2005 American Institute of Chemical Engineers AIChE J, 2006
A model for bubble–bubble and bubble–wall interaction in bubble formation
Authors: Xiao Zongyuan , Tan Reginald B. H.
Published: September 2005

A theoretical model for bubble formation at a submerged orifice has been developed, which takes into account the interaction between the column wall and the growing bubble at the orifice, as well as the interaction between subsequent bubbles formed and detached from the orifice. Experiments involving high‐speed photography and bubble frequency measurements were carried out with different chamber volumes, column and orifice diameters, and gas flow. In particular, it was found that decreasing the column diameter (that is, increasing the bubble–wall interaction) led to increased bubble–bubble interaction, as evidenced by a greater tendency for pairing and multiple bubbling. Simulated results using the theoretical model agreed very well with experimental data. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Assay of urinary α‐fluoro‐β‐alanine by gas chromatography–mass spectrometry for the biological monitoring of occupational exposure to 5‐fluorouracil in oncology nurses and pharmacy technicians
Authors: Rubino Federico Maria , Verduci Cinzia , Buratti Marina , Fustinoni Silvia , Campo Laura , Omodeo‐Salè Emanuela , Giglio Margherita , Iavicoli Sergio , Brambilla Gabri , Colombi Antonio
Published: September 2005

The validation of an analytical method for the measurement of the unnatural amino acid α‐fluoro‐β‐alanine (AFBA), the main metabolite of the antineoplastic drug 5‐fluorouracil (5FU), in urine for the biological monitoring of the exposure of hospital workers to the drug when preparing the therapeutical doses and administering to cancer patients is described. The method employed a two‐step extractive derivatization of the analyte from urine to the N‐trifluoroacety‐n‐butyl ester derivative and detection by selected‐ion monitoring gas chromatography–mass spectrometry of structurally specific fragments. The limit of detection was 20 ng/mL with quantification accuracy better than ±20% and precision (CV%) better than ±20% in the range 0.020–10 µg/mL. Norleucine was used as the internal standard and the sample‐to‐sample analysis time was less than 15 min. The validated method has been applied to the biological monitoring of some hospital workers potentially exposed to 5FU and to matched control subjects. On a total number of 65 analyzed urine samples from control and exposed subjects, only three, obtained from exposed subjects, were found to be positive, with values of 20, 30 and 1150 ng/mL, respectively. Copyright © 2005 John Wiley & Sons, Ltd.
Entropy‐based motion extraction for motion capture animation
Authors: So Clifford K. F. , Baciu George
Published: September 2005

In this paper, we present a new segmentation solution for extracting motion patterns from motion capture data by searching for critical keyposes in the motion sequence. A rank is established for critical keyposes that identifies the significance of the directional change in motion data. The method is based on entropy metrics, specifically the mutual information measure. Displacement histograms between frames are evaluated and the mutual information metric is employed in order to calculate the inter‐frame dependency. The most significant keypose identifies the largest directional change in the motion data. This will have the lowest mutual information level from all the candidate keyposes. Less significant keyposes are then listed with higher mutual information levels. The results show that the method has higher sensitivity in the directional change than methods based on the magnitude of the velocity alone. This method is intended to provide a summary of a motion clip by ranked keyposes, which is highly useful in motion browsing and motion retrieve database system. Copyright © 2005 John Wiley & Sons, Ltd.
A feature‐based approach to facial expression cloning
Authors: Park Bongcheol , Chung Heejin , Nishita Tomoyuki , Shin Sung Yong
Published: September 2005

In this paper, we present a feature‐based approach to cloning facial expressions from an input face model to an output model, using predefined source key‐models and the corresponding target key‐models. Adopting a scattered data interpolation technique, our approach consists of two parts: analysis of face key‐models and synthesis of facial expressions. In the analysis part carried out once at the beginning, key‐models are segmented automatically into five regions, each containing one of five facial features, that is, eyes, cheeks, and the mouth, which give rise to five sets of source key‐shapes and the corresponding sets of target key‐shapes. Using the key‐shapes of each source feature, those of the corresponding target feature are parameterized. In the synthesis part, given a sequence of face models comprising an input animation, five output features are obtained separately by blending their own target key‐shapes. These separately produced features are combined to synthesize the output face model at each frame. Our feature‐based approach enables cloning of diverse expressions including asymmetric ones convincingly with a small number of face key‐models while exhibiting an on‐line, real‐time performance. Copyright © 2005 John Wiley & Sons, Ltd.
Controllable local monotonic cubic interpolation in fluid animations
Authors: Ihm Insung , Cha Deukhyun , Kang Byungkwon
Published: September 2005

While linear interpolation has been used frequently in computer graphics, higher‐order interpolation is often desirable in applications requiring higher‐order accuracy. In this paper, we study how interpolation filters, employed to resample such data as velocity, density, and temperature in simulating the equations of fluid dynamics, affect the animation of fluids. For this purpose, we have designed a controllable local cubic interpolation scheme that offersG1(orC1) continuity globally. It is based on monotonic splines so does not suffer from undue overshooting. Furthermore, it is possible to control the general behavior of the interpolation through a global tension parameter, providing a continuous spectrum of linear to cubic interpolation. We analyze how this controllable interpolation filter may be effectively used to enhance the visual reality for physically based fluid animation. Copyright © 2005 John Wiley & Sons, Ltd.
Extending the photon mapping method for realistic rendering of hot gaseous fluids
Authors: Kang Byungkwon , Ihm Insung , Bajaj Chandrajit
Published: September 2005

With the increased sophistication and use of heated gas, fire, and explosion simulations in computer graphics applications, there is a corresponding impetus to improve the visual realism in the rendering of such simulated phenomena. In visualizing these turbulent fluids, an appropriate incorporation of their incandescent properties into the rendering significantly enhances the realism of visual effects. In this paper, we effectively synthesize the light emission phenomena of hot gaseous fluids by extending the photon mapping global illumination method. In particular, we add two new photon maps to capture the thermal radiation effects. First, we define anemissionphoton map to store the photons emitted within hot gaseous fluids. Second, we utilize additionalflashandflash reflectionphoton maps, which are effective in creating a visual effect of light that intensively and instantly propagates outside hot gaseous fluids, visually capturing shock waves. Our current technique, while based on the theory of blackbody radiation, is parameterized to enable an animator to generate a wide range of visual effects with fairly intuitive user control. We demonstrate the effectiveness of our new rendering technique and user‐controlled generation of visual effects with several example pictures and animations. Copyright © 2005 John Wiley & Sons, Ltd.
Mechanism Studies of the Conversion of 13C‐Labeled n‐Butane on Zeolite H‐ZSM‐5 by Using 13C Magic Angle Spinning NMR Spectroscopy and GC–MS Analysis
Authors: Luzgin Mikhail V. , Stepanov Alexander G. , Arzumanov Sergei S. , Rogov Vladimir A. , Parmon Valentin N. , Wang Wei , Hunger Michael , Freude Dieter
Published: September 2005

By using 13C MAS NMR spectroscopy (MAS=magic angle spinning), the conversion of selectively 13C‐labeled n‐butane on zeolite H‐ZSM‐5 at 430–470 K has been demonstrated to proceed through two pathways: 1) scrambling of the selective 13C‐label in the n‐butane molecule, and 2) oligomerization–cracking and conjunct polymerization. The latter processes (2) produce isobutane and propane simultaneously with alkyl‐substituted cyclopentenyl cations and condensed aromatic compounds. In situ 13C MAS NMR and complementary ex situ GC–MS data provided evidence for a monomolecular mechanism of the 13C‐label scrambling, whereas both isobutane and propane are formed through intermolecular pathways. According to 13C MAS NMR kinetic measurements, both pathways proceed with nearly the same activation energies (Ea=75 kJ mol−1 for the scrambling and 71 kJ mol−1 for isobutane and propane formation). This can be rationalized by considering the intermolecular hydride transfer between a primarily initiated carbenium ion and n‐butane as being the rate‐determining stage of the n‐butane conversion on zeolite H‐ZSM‐5.
Remediation of soil contaminated with arsenic, zinc, and nickel by pilot‐scale soil washing
Authors: Ko Ilwon , Lee Cheol‐Hyo , Lee Kwang‐Pyo , Lee Sang‐Woo , Kim Kyoung‐Woong
Published: September 2005

The use of soil washing has successfully demonstrated bench‐scale and field applications for the remediation of oxyanions and cationic heavy metals. However, it is not easy to simultaneously remove both oxyanions and cations using one wash solution in the same extraction. Also contaminated soils from metal mining areas present other difficulties to remove contaminants because of their strong binding properties. Correspondingly, the efficiency of soil washing can be inhibited by the limited extraction of contaminants. The objective of this study was to find the optimal process conditions for the enhanced washing of recalcitrant contaminants. This study focused on the effectiveness of engineering‐scale washing of field soil using three types of inorganic acids (HCl, H2SO4, and H3PO4). In this study, soil contaminated with arsenic, nickel, and zinc was obtained from a closed iron/serpentine mining area. The H2SO4 and H3PO4 wash solutions, including the competitive oxyanion, enhanced the removal of arsenic. The acid attack on arsenic binding in the Fe/Mn oxide and organic/sulfides fractions may be a possible removal mechanism in addition to anionic competitive desorption. The low efficiency of soil washing results from the strong binding associated with minerals and the enrichment of contaminants in the highly reactive fine particles. For this soil used, the physical separation of particles could enhance the overall effectiveness of soil washing. Therefore, for the soils contaminated with recalcitrant contaminants in metal mining areas, the physical separation of fine particles can be significant in addition to the chemical extraction. © 2005 American Institute of Chemical Engineers Environ Prog, 2005