bluuebunny/crossref_metadata_2025 huggingface dataset:
Ketogenic diet protects the hippocampus from kainic acid toxicity by inhibiting the dissociation of bad from 14‐3‐3
Authors: Noh Hae Sook , Kim Yoon Sook , Kim Young Hee , Han Jae Yoon , Park Chang Hwan , Kang Ahn Ki , Shin Hee Suk , Kang Sang Soo , Cho Gyeong Jae , Choi Wan Sung
Published: October 2006

The ketogenic diet (KD) is often effective for intractable epilepsy, but its antiepileptic mechanisms remain largely unknown. Within the cell death/survival pathway, Akt and its downstream protein Bad play an important role in kainic acid (KA)‐induced cell death. Therefore, we investigated the effects of a KD on KA‐induced changes in the Akt/Bad/14‐3‐3 signaling pathway by evaluating Akt, Bad, 14‐3‐3, and cleaved caspase‐3 expression levels as well as their relative interactions. Our results showed that a KD did not affect the expression levels of Akt, Bad, Bcl‐xL, Bax, and 14‐3‐3 but increased phospho‐Akt [serine 473; p‐Akt (Ser473)] and phospho‐Bad [serine 136; p‐Bad (Ser136)] expression levels as well as decreased cleaved caspase‐3 levels following a KA‐induced seizure in the hippocampus. Furthermore, we found that a KD increased the protein–protein interaction between 14‐3‐3 and p‐Bad (Ser136), which might be phosphorylated by p‐Akt (Ser473), and decreased interaction of Bad and Bcl‐xL. These results suggest that a KD might protect, at least partially, the hippocampus from KA‐induced cell death via inhibiting the dissociation of Bad from 14‐3‐3. © 2006 Wiley‐Liss, Inc.
Spatiotemporal Expression of Heme Oxygenase-1 Detected by in Vivo Bioluminescence After Hepatic Ischemia in Ho-1/Luc Mice
Authors: Su Huawei , van Dam Gooitzen M. , Buis Carlijn I. , Visser Dorien S. , Hesselink Jan Willem , Schuurs Theo A. , Leuvenink Henri G.D. , Contag Christopher H. , Porte Robert J.
Published: October 2006

Upregulation of heme oxygenase-1 (HO-1) has been proposed as a critical mechanism protecting against cellular stress during liver transplantation, providing a potential target for new therapeutic interventions. We investigated the feasibility of in vivo bioluminescence imaging (BLI) to noninvasively quantify the spatiotemporal expression of HO-1 after warm hepatic ischemia in living animals. Luciferase activity was measured by BLI as an index of HO-1 transcription in transgenic reporter mice (Ho1-luc) at standardized time points after 60 minutes of warm hepatic ischemia. HO-1 mRNA levels were measured in postischemic livers of mice sacrificed at the same time points in separate experiments. Bioluminescent signals from postischemic liver lobes were first detected at 3 hours after reperfusion. Peak levels were reached at 9 hours, after which bioluminescent activity declined and returned to baseline values at 48 hours after reperfusion. Upregulation of HO-1 as detected by in vivo BLI was preceded by increased HO-1 mRNA expression and confirmed by enhanced immunohistochemical staining of hepatocytes. In conclusion, this study shows that in vivo BLI allows a sensitive assessment of HO-1 expression after hepatic ischemia in living animals. The capability of whole-body temporal imaging of HO-1 expression provides a valuable tool in the development of novel strategies to modulate HO-1 expression in liver transplantation.
Liver Transpl 12:1634–1639, 2006.

© 2006 AASLD.
Acute Liver Failure in Children: They Really Are Not Just Small Adults: Acute Liver Failure in Children: the First 348 Patients in the Pediatric Acute Liver Failure Study Group. Squires Rh Jr, Shneider Bl, Bucuvalas J, Alonso E, Sokol Rj, Narkewicz, Et Al. J Pediatr 2006;148:652-658.
Authors: Perkins James D.
Published: October 2006

Abstract

Objectives:

To determine short-term outcome for children with acute liver failure (ALF) as it relates to cause, clinical status, and patient demographics and to determine prognostic factors.

Study design:

A prospective, multicenter case study collecting demographic, clinical, laboratory, and short-term outcome data on children from birth to 18 years with ALF. Patients without encephalopathy were included if the prothrombin time and international normalized ratio remained ≥20 seconds and/or >2, respectively, despite vitamin K. Primary outcome measures 3 weeks after study entry were death, death after transplantation, alive with native liver, and alive with transplanted organ.

Results:

The cause of ALF in 348 children included acute acetaminophen toxicity (14%), metabolic disease (10%), autoimmune liver disease (6%), non-acetaminophen drug-related hepatotoxicity (5%), infections (6%), other diagnosed conditions (10%); 49% were indeterminate. Outcome varied between patient sub-groups; 20% with non-acetaminophen ALF died or underwent liver transplantation and never had clinical encephalopathy.

Conclusions:

Causes of ALF in children differ from in adults. Clinical encephalopathy may not be present in children. The high percentage of indeterminate cases provides an opportunity for investigation. (J Pediatr 2006;148:652-658.)
Revised statistical motor unit number estimation in the Celecoxib/ALS trial
Authors: Shefner J. M. , Cudkowicz M. E. , Zhang H. , Schoenfeld D. , Jillapalli D. ,   The Northeast ALS Consortium
Published: October 2006

Techniques to estimate motor unit number (MUNE) measure the number of functioning motor units in a muscle. As amyotrophic lateral sclerosis (ALS) is characterized by progressive motor unit loss, this disease offers an ideal setting for the use of MUNE. Statistical MUNE was employed in a recent multicenter trial of creatine in ALS, and was shown to be reliable, reproducible, and to decline with disease progression. However, motor unit amplitude stayed constant over 7 months, a finding believed to reflect an artifact of the method. The statistical method was revised to reflect more accurately the presence of larger motor units and employed in a 12‐month study of Celecoxib in ALS. MUNE declined by 49% in 12 months; however, motor unit amplitude again stayed constant over the same period. Statistical MUNE estimates motor unit number based on the variability of response to a repeated stimulus of constant strength, with an underlying assumption that this variability is due solely to the number of motor units responding in an intermittent manner. Based on studies showing that single motor units in ALS display excessive amplitude variability when stimulated repeatedly, we show that response variability in ALS patients is in large part due to single unit changes. Thus, we conclude that the statistical method is not an appropriate measure of motor unit number in any disease associated with motor unit instability. Muscle Nerve, 2006
Anabolic effects of a non‐myotoxic dose of the β2‐adrenergic receptor agonist clenbuterol on rat plantaris muscle
Authors: Burniston Jatin G. , McLean Lynn , Beynon Robert J. , Goldspink David F.
Published: October 2006

Previous investigations of the effects of clenbuterol have used suprapharmacological doses that induce myocyte death, alter muscle phenotype, and do not approximate the proposed therapeutic dose for humans. Recently, we reported that smaller doses of clenbuterol induce muscle growth without causing myocyte death. In the present study we used histochemical and proteomic techniques to investigate the molecular effects of this dose. Male Wistar rats (n = 6, per group) were infused with saline or 10 μg/kg/day clenbuterol via subcutaneously implanted osmotic pumps. After 14 days the animals' plantaris muscles were isolated for histochemical and proteomic analyses. Clenbuterol induced significant muscle growth with concomitant protein accretion and preferential hypertrophy of fast oxidative glycolytic fibers. Clenbuterol reduced the optical density of mitochondrial staining in fast fibers by 20% and the glycogen content of the muscle by 30%. Differential analysis of two‐dimensional gels showed that heat shock protein 72 and β‐enolase increased, whereas aldolase A, phosphogylcerate mutase, and adenylate kinase decreased. Only heat shock protein 72 has previously been investigated in clenbuterol‐treated muscles. The clenbuterol‐induced increase in muscle growth was concomitant with qualitative changes in the muscle's proteome that need to be considered when proposing therapeutic uses for this agent. Muscle Nerve, 2006
Genomic integration of oncogenic HPV and gain of the human telomerase gene TERC at 3q26 are strongly associated events in the progression of uterine cervical dysplasia to invasive cancer
Authors: Hopman AHN , Theelen W , Hommelberg PPH , Kamps MAF , Herrington CS , Morrison LE , Speel E‐JM , Smedts F , Ramaekers FCS
Published: October 2006

Recently proposed events associated with the progression of cervical intraepithelial neoplasia (CIN) 2/3 to cervical carcinoma include integration of human papillomavirus (HPV) into the host genome, genomic instability, and an increase in chromosome 3q copy number. In particular, the gene coding for the RNA component of telomerase (TERC) at 3q26 has been implicated as a possible candidate gene. Since it is not known to date how these events are temporally related during cervical carcinogenesis, the aim of the present study was to assess the correlation between TERC gene copy number and the physical status of HPV during progression in cervical neoplasia. Solitary precursor lesions of the uterine cervix (CIN 2/3, n = 17), lesions associated with a micro‐invasive carcinoma (CIN 3&mCA, n = 13), and advanced invasive carcinomas (invCA, n = 7) were analysed by fluorescence in situ hybridization (FISH) to determine the physical status of the virus and TERC gene copy number. The TERC gene was increasingly gained with progression of CIN 2/3 (3 of 17) through CIN 3&mCA (7 of 13) to invCA (5 of 7). In the lesions exhibiting gain of TERC, the virus was predominantly integrated. This was seen in eight of ten diploid lesions, indicating that these events can occur prior to aneuploidization and are strongly associated with the progression of CIN 3 to mCA and invCA (p < 0.001). With progression to carcinoma, a number of these lesions show polyploidization, resulting in aneuploidy and high TERC gene copy numbers. In conclusion, genomic integration of oncogenic HPV and gain of the human telomerase gene TERC appear to be important associated genetic events in the progression of uterine cervical dysplasia to invasive cancer. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Identification of transmembrane proteins as potential prognostic markers and therapeutic targets in breast cancer by a screen for signal sequence encoding transcripts
Authors: Esseghir S , Reis‐Filho JS , Kennedy A , James M , O'Hare MJ , Jeffery R , Poulsom R , Isacke CM
Published: October 2006

This study demonstrates, through a combination of stringent screening methods and thorough validation, that it is possible to identify transmembrane proteins preferentially expressed in primary breast tumour cells. mRNA was extracted from tumour cells isolated from invasive breast cancers and it was then subtracted against normal breast tissue mRNA prior to the generation of a signal sequence‐trap library. Screening of the library identified 31 positive clones encoding 12 cell‐surface and 12 secreted proteins. The expression of a subset of transmembrane genes was then interrogated using a high‐throughput method (tissue microarray) coupled with cutting‐edge in situ techniques in a large cohort of patients who had undergone uniform adjuvant chemotherapy. Expression of CD98 heavy chain (CD98HC) and low‐level expression of the insulin‐like growth factor 2 receptor/mannose‐6‐phosphate receptor (IGF2R/M6PR) correlated with poor patient prognosis in the whole cohort. Expression of bradykinin receptor B1 (BDKRB1) and testis enhanced gene transcript (TEGT) correlated with good prognosis in woman with oestrogen receptor (ER)‐negative breast tumours. These results indicate that this combined approach of isolating primary tumour cells, generating a library to specifically isolate signal‐sequence‐containing transcripts, and in situ hybridization on tissue microarrays successfully identified novel prognostic markers (BDKRB1, CD98hc, and TEGT) and potential transmembrane therapeutic targets (CD98hc) in breast cancer. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Functional modification of biodegradable polyesters through a chemoselective approach: application to biomaterial surfaces
Authors: Taniguchi Ikuo , Kuhlman William A , Mayes Anne M , Griffith Linda G
Published: October 2006

This paper presents an overview of functional modifications of synthetic aliphatic polyesters and a new synthetic route to graft functional moieties onto the polyester backbone by a chemoselective approach. Aminooxy groups react efficiently and selectively with ketones or aldehydes to form oxime linkages under mild reaction conditions without catalysts, even in the presence of other functional groups. Chemoselective coupling of aminooxy‐terminated poly(ethylene oxide) (PEO) onto ketone‐bearing poly(ε‐caprolactone) (PCL) was exploited to prepare comb‐shaped copolymers that exhibit cell resistance when the PEO content is above 30 wt%. The free hydroxyl groups of PEO chain ends allowed further incorporation of cell signaling peptides including the sequence RGD. The results show chemoselective coupling to be a promising general route for introducing functional pendant groups onto most polyesters obtained by ring‐opening polymerization without backbone degradation. Copyright © 2006 Society of Chemical Industry
Dual photo‐ and thermally initiated cationic polymerization of epoxy monomers
Authors: Crivello James V. , Bulut Umut
Published: October 2006

Selective inhibition of the photoinitiated cationic ring‐opening polymerization of epoxides by dialkyl sulfides has provided dual systems that can be “activated” by UV irradiation and then subsequently be polymerized by the application of heat. It is proposed that dialkyl sulfides terminate the initial or growing polyether chains at an early stage to form stable trialkylsulfonium salts. These systems are dormant at room temperature but on thermolysis, the sulfonium salts are capable of reinitiating ring‐opening polymerization. These dual photo‐ and thermal cure systems have potential applications in adhesives, potting resins, and composites. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6750–6764, 2006
Interleukin‐1β induces sialyl Lewis X on hepatocellular carcinoma HuH‐7 cells via enhanced expression of ST3Gal IV and FUT VI gene
Authors: Higai Koji , Miyazaki Noriko , Azuma Yutaro , Matsumoto Kojiro
Published: October 2006

We previously demonstrated that human hepatocellular carcinoma‐derived HuH‐7 cells stimulated with interleukin‐1β (IL‐1β) produce α1‐acid glycoprotein (AGP) with increased amounts of sialyl Lewis X (sLeX) antigen, although the mechanism remained obscure. Here, we report our investigation of the mechanism. sLeX expression on HuH‐7 cells was induced 2.5 times more after 48 h stimulation with 100 U/mL IL‐1β compared with control, as indicated by anti‐sLeX antibody binding. Furthermore, expression of 2,3‐sialylated N‐acetyllactosamine increased gradually up to 48 h after IL‐1β stimulation; this preceded the increase in sLeX expression. Increases in α2,3‐sialyltransferase activity also preceded increases in α1,3‐fucosyltransferase activity. Furthermore, mRNA levels of ST3Gal IV, FUT IV and VI in HuH‐7 cells stimulated with IL‐1β were increased at 2–4 h, while increases in FUT VI mRNA level occurred gradually after 24 h. IL‐1β‐induced sLeX expression on HuH‐7 cells was suppressed by transfection of gene‐specific small interference RNAs against FUT VI and ST3Gal IV but not against FUT IV and ST3Gal III. These data results that IL‐1β induces expression of sLeX on HuH‐7 cells by enhanced expression of FUT VI and ST3Gal IV gene.
Dorsal (AO/ASIF) Pi-Plate Osteosynthesis in the Treatment of Distal Intraarticular Radius Fractures
Authors: SUCKEL A. , SPIES S. , MÜNST P.
Published: October 2006

The results and complications using the dorsal 2.4 mm 2.7 mm (AO/ASIF) pi-plate for the treatment of distal radius fractures were evaluated in a prospective study of 42 patients followed up clinically and radiologically and seven patients followed up with telephone call and radiological follow-up for an average time of 12.1 (range 4–32) months in a group of 50 patients with intraarticular distal radial fractures treated consecutively using this method. Twelve complications occurred in 10 patients including two extensor tendon ruptures, two transient cases of CRPS Type 1 (Reflex Sympathetic Dystrophy, Algodystrophy), two instances of screw loosening, three cases of posttraumatic carpal tunnel syndrome and three permanent sensory irritations on the dorsum of the hands. Using the AO score, there were 37 successful and 12 tolerable results, with no unsatisfactory outcomes. Using the NYOWR scale, there were 17 very good and 25 good results, with no satisfactory or poor outcomes. These results suggest that this osteosynthesis provides adequate fixation of comminuted distal intraarticular radius fractures with a reasonable incidence of complications.
Towards a Genealogy and Taxonomy of British Alternative Theatre
Authors: Freeman Sara
Published: October 2006

In the third volume of The Cambridge History of British Theatre (2004), editor Baz Kershaw initiates his chapter ‘Alternative Theatres, 1946–2000’ with a short discussion of ‘contesting terms’ used by commentators to describe theatre outside the mainstream in the second half of the twentieth century. Kershaw's discussion serves as a necessary preface to ground his use of multiple historiographical strategies to address the subject with necessary brevity. But teasing out the terminology used to describe alternative theatre remains a fascinatingly complex task, constitutive of precisely the issues at stake in the variant historiographical approaches to the post-war period. Using a genealogical approach inspired by Foucault, and drawing on first-person interviews with artists who worked with alternative theatre companies such as Joint Stock/Out of Joint, Gay Sweatshop, and Women's Theatre Group/The Sphinx across the closing decades of the twentieth century, Sara Freeman analyzes the branching relationships of these terms, arguing the need to develop useful rather than funerary or bewildered historiographical approaches to the 1980s and 1990s. Sara Freeman is Assistant Professor of Theatre at Illinois Wesleyan University. Her research focuses on contemporary women playwrights and British alternative theatre, and she has published articles and reviews in Theatre Survey, Modern Drama, Comparative Drama, New England Theatre Journal, and Theatre Journal. Work on this article was supported by an Artistic and Scholarly Development Grant from Illinois Wesleyan University.
Comparison of diets of the acouchy, agouti and paca, the three largest terrestrial rodents of French Guianan forests
Authors: Dubost Gérard , Henry Olivier
Published: October 2006

The diets of the acouchy Myoprocta exilis, agouti Dasyprocta leporina and paca Agouti paca, the three largest terrestrial rodents of French Guiana forests, were investigated from stomachs collected over several years. These species are primarily frugivores. The percentage of fruit in their diet decreased, and seasonal variation increased from the smallest species, the acouchy, to the largest, the paca (contents in dry mass: respectively, 98.5% ± 0.6%, 87.4% ± 3.5%, and 83.9% ± 7.6%). They differed from each other in the proportions of pulp and secondary foods (leaves, fibre, insects) consumed annually as well as seasonally. Dietary diversity in the acouchy was half that of the two other species. The seasonal variation in consumption of different fruit parts and of secondary foods by these species corresponded well with the fruit production in the forest, and was linked to their reproductive events. Overall, the diets of these three large rodents appeared intermediate between the small rodent species and the artiodactyls (peccaries and brocket deer) inhabiting the same areas, which also concords with their body mass and their place within the guild of terrestrial mammals.
One size fits all: corolla compression in Aphelandra runcinata (Acanthaceae), an adaptation to short-billed hummingbirds
Authors: Rengifo Carlos , Cornejo Luis , Akirov Iván
Published: October 2006

Co-evolutionary processes have moulded interactions between hummingbirds (Trochilidae) and ornithophilous flowers. Generally, long corollas exclude short-billed trochilids, whereas short corollas allow access for both long- and short-billed species. At La Mucuy, Sierra Nevada National Park, Mérida, Venezuela, we studied interactions between Aphelandra runcinata (Acanthaceae) and its avian pollinators. Of 13 trochilid species reported from this site, only two, Coeligena torquata and C. eos, have bills long enough to allow legitimate access to the nectar of A. runcinata flowers. However, we observed that hummingbirds with much shorter bills were also able to extract nectar and pollinate the flowers. This is due to a reversible compression mechanism in A. runcinata, caused by the pressure exerted by the bird in flight and the physical opposition of the inflorescence. The compression mechanism observed in A. runcinata flowers is a morphological characteristic that provides mutualistic advantages for both the plant and its avian visitors. The spectrum of potential pollinators is increased by giving access to nectar even to species with short or medium-long bills. Moreover, nectar-robbing, a foraging strategy that does not result in pollen transfer common among short-billed trochilids, seems to be reduced.
Dispersal of fig pollinators in Asian tropical rain forests
Authors: Harrison Rhett D. , Rasplus Jean-Yves
Published: October 2006

Fig pollinators (Agaonidae, Chalcioidea) lay their eggs in fig inflorescences (Ficus, Moraceae). Reproductive success for both partners is thus largely dependent on the dispersal of these tiny wasps. Some are known to cover substantial distances (> 10 km) using wind above the canopy. However, fig ecology is extremely varied, and hence one might also expect a diversity of pollinator dispersal strategies. We studied fig pollinator dispersal in Sarawak (2001 and 2004) and Peninsular Malaysia (2003). The results indicate substantial differences in dispersal ecology between the pollinators of monoecious and dioecious figs. Monoecious-fig pollinators were common, and species composition and rank abundances were similar between years despite short sampling periods. Substantial temporal and spatial variation in their production is thus smoothed out by long-distance dispersal. Some species whose hosts do not occur at our Sarawak site and are rare throughout Borneo were caught, suggesting exceptionally long-distance dispersal in these species. Conversely, few dioecious-fig pollinators were caught and species overlap between years was low. Dispersal range in many dioecious-fig pollinators may be more restricted. At a finer scale, among genera pollinating monoecious figs we found marked differences in flight behaviour (height and time-of-dispersal). We relate these findings to the ecology of their hosts, and discuss the implications for fig–fig-pollinator coevolution.
Positive effect of seed size on seedling survival in fire-prone savannas of Australia, Brazil and West Africa
Authors: Lahoreau Gaëlle , Barot Sébastien , Gignoux Jacques , Hoffmann William A. , Setterfield Samantha A. , Williams Paul R.
Published: October 2006

All plant species face a fundamental reproductive trade-off: for a given investment in seed mass, they can produce either many small seeds or few large seeds. Whereas small seeds favour the germination of numerous seedlings, large seeds favour the survival of seedlings in the face of common stresses such as herbivory, drought or shade (Leishman et al. 2000). One mechanism explaining the better survival of large-seeded species is the seedling size effect (SSE) (Westoby et al. 1996): because seeds with large reserves result in bigger seedlings, seedlings from large-seeded species would have better access to light and/or to reliable water supply than seedlings from small-seeded species.
Embryonic development and mortality in Hyalinobatrachium pulveratum (Anura: Centrolenidae) of south-western Costa Rica
Authors: Hawley Tanya J.
Published: October 2006

The population biology and ecology of most members of the neotropical family Centrolenidae, or glass frogs, are unknown. Glass frogs deposit their eggs in a gelatinous mass on vegetation overhanging streams, the eggs hatch, and the tadpoles drop into the water, where they complete development (Savage 2002). This study will contribute to our limited understanding of centrolenid reproductive ecology by quantifying variation in clutch size, embryonic development and embryonic mortality in a population of Hyalinobatrachium pulveratum.
Adjacent pastoral areas support higher densities of wild ungulates during the wet season than the Lake Mburo National Park in Uganda
Authors: Rannestad Ole Tobias , Danielsen Torbjørn , Moe Stein R. , Stokke Sigbjørn
Published: October 2006

The small size of many African protected areas makes adjacent rangelands potentially important in the local survival of wild animals. In order to assess the importance of pastoral areas to wild ungulates, we studied density and habitat choice of wild ungulates and cattle in Lake Mburo National Park, Uganda, the adjacent exclusively pastoral Nshara Dairy Ranch and on private land consisting of a mixture of ranching and subsistence farms. Transects, in the three land-use zones, were walked during the wet season and the data were analysed by DISTANCE sampling technique. We found significantly higher total density of wild ungulates on the dairy ranch compared with the National Park and private land. There was no significant difference in total wild animal density between the National Park and private land. Impala (Aepyceros melampus), zebra (Equus quagga), bushbuck (Tragelaphus scriptus) and waterbuck (Kobus ellipsiprymnus) had significantly higher densities on the dairy ranch compared to the National Park. Only eland (Taurotragus oryx) density was higher in the National Park compared to private land. Wild ungulates and cattle showed a high degree of habitat overlap, generally preferring open grassland. Our study shows that high densities of wild ungulates are not necessarily associated with protected areas. Pastoral areas may be important for populations of wild herbivores during the growing season despite a pronounced presence of livestock.
Cross-language comparisons of maze use in Spanish and English in functionally monolingual and bilingual children
Authors: BEDORE LISA M. , FIESTAS CHRISTINE E. , PEÑA ELIZABETH D. , NAGY VANESSA J.
Published: October 2006

Maze use appears to be higher in bilingual speakers than in their functionally monolingual peers. One question is whether this is due to the speaker's bilingual status or to the characteristics of the bilingual's language(s). Narratives for 22 Spanish–English bilingual 4–6-year-olds and their functionally monolingual age-matched peers were analyzed for maze use. Bilingual and functionally monolingual children used similar percentages and patterns of mazes. Children produced more grammatical revisions in Spanish than English. Bilingual and functionally monolingual children used similar grammatical revision strategies in Spanish and English. Children's maze use in each language was correlated with measures of language productivity such as mean length of utterance and number of words used in the sample. These findings suggest that the role of language is important in maze use and that bilingual children do not necessarily have greater levels of linguistic uncertainty than do their functionally monolingual peers.
Is he floating across or crossing afloat? Cross-influence of L1 and L2 in Spanish–English bilingual adults
Authors: HOHENSTEIN JILL , EISENBERG ANN , NAIGLES LETITIA
Published: October 2006

Research has begun to address the question of transfer of language usage patterns beyond the idea that people's native language (L1) can influence the way they produce a second language (L2). This study investigated bidirectional transfer, of both lexical and grammatical features, in adult speakers of English and Spanish who varied in age of L2 acquisition. Early and late learners of English watched and orally described video depictions of motion events. Findings suggest bilinguals' patterns of motion description lexically and grammatically resemble those of monolinguals in each language. However, although participants showed bidirectional lexical transfer, they displayed only L1-to-L2 grammatical transfer. Furthermore, learning L2 post-puberty affected L2 lexical choice, but both early and late L2 learners showed L2 influence on L1 lexical choice. Finally, the findings of grammatical transfer and age of acquisition were mixed. We discuss results with reference to theories of cross-language transfer.
A cross-cultural study on the use of gestures: Evidence for cross-linguistic transfer?
Authors: PIKA SIMONE , NICOLADIS ELENA , MARENTETTE PAULA F.
Published: October 2006

Anecdotal reports provide evidence of so called “hybrid” gesturer whose non-verbal behavior of one language/culture becomes visible in the other. The direction of this gestural transfer seems to occur from a high to a low frequency gesture language. The purpose of this study was therefore to test systematically 1) whether gestural transfer occurs from a high frequency gesture language to a low frequency gesture language, 2) if the frequency of production of some gesture types is more likely to be transferred than others, and 3) whether gestural transfer can also occur bi-directionally. To address these questions, we investigated the use of gestures of English–Spanish bilinguals, French–English bilinguals, and English monolinguals while retelling a cartoon. Our analysis focused on the rate of gestures and the frequency of production of gesture types. There was a significant difference in the overall rate of gestures: both bilingual groups gestured more than monolingual participants. This difference was particularly salient for iconic gestures. In addition, we found that French–English bilinguals used more deictic gestures in their L2. The results suggest that knowledge of a high frequency gesture language affects the gesture rate in a low-frequency gesture language.
Radiative transfer calculations for a passive microwave satellite sensor: Comparing a fast model and a line‐by‐line model
Authors: Buehler S. A. , Courcoux N. , John V. O.
Published: October 2006

A comparison between the fast radiative transfer model Radiative Transfer for the TIROS Operational Vertical Sounder (RTTOV‐7) and the physical radiative transfer model Atmospheric Radiative Transfer Simulator (ARTS) was carried out. Radiances were simulated for the sounding channels of the Advanced Microwave Sounding Unit B (AMSU‐B) for the whole globe for a single time of a single day (1 January 2000, 0000 UT). Temperature, pressure, and specific humidity profiles from the reanalysis data set ERA‐40 of the European Centre for Medium‐Range Weather Forecasts (ECMWF) were used as input for both models; geopotential height profiles were also used but only as input for ARTS. The simulations were made for two different surface emissivities, 0.60 and 0.95. The low surface emissivity case exhibits the larger radiance differences. Although the global values of the mean difference and standard deviation are small (for example, the global mean difference for channel 18 is 0.014 K and the standard deviation is 0.232 K), the examination of the geographical distribution of the differences shows that large positive or negative values are observed over dry regions of high northern and southern latitudes and over dry elevated regions. The origin of these differences was found to be due to errors introduced by the transmittance parametrization used in RTTOV.
Three‐dimensional waveform modeling of ionospheric signature induced by the 2004 Sumatra tsunami
Authors: Occhipinti Giovanni , Lognonné Philippe , Kherani E. Alam , Hébert Hélène
Published: October 2006

The Sumatra, December 26th, 2004, tsunami produced internal gravity waves in the neutral atmosphere and large disturbances in the overlying ionospheric plasma. To corroborate the tsunamigenic hypothesis of these perturbations, we reproduce, with a 3D numerical modeling of the ocean‐atmosphere‐ionosphere coupling, the tsunami signature in the Total Electron Content (TEC) data measured by the Jason‐1 and Topex/Poseidon satellite altimeters. The agreement between the observed and synthetic TEC shows that ionospheric remote sensing can provide new tools for offshore tsunami detection and monitoring.
A distinct PAR complex associates physically with VE‐cadherin in vertebrate endothelial cells
Authors: Iden Sandra , Rehder Daniela , August Benjamin , Suzuki Atsushi , Wolburg‐Buchholz Karen , Wolburg Hartwig , Ohno Shigeo , Behrens Jürgen , Vestweber Dietmar , Ebnet Klaus
Published: October 2006

A cell polarity complex consisting of partitioning defective 3 (PAR‐3), atypical protein kinase C (aPKC) and PAR‐6 has a central role in the development of cell polarity in epithelial cells. In vertebrate epithelial cells, this complex localizes to tight junctions. Here, we provide evidence for the existence of a distinct PAR protein complex in endothelial cells. Both PAR‐3 and PAR‐6 associate directly with the adherens junction protein vascular endothelial cadherin (VE‐cadherin). This association is direct and mediated through non‐overlapping domains in VE‐cadherin. PAR‐3 and PAR‐6 are recruited independently to cell–cell contacts. Surprisingly, the VE‐cadherin‐associated PAR protein complex lacks aPKC. Ectopic expression of VE‐cadherin in epithelial cells affects tight junction formation. Our findings suggest that in endothelial cells, another PAR protein complex exists that localizes to adherens junctions and does not promote cellular polarization through aPKC activity. They also point to a direct role of a cadherin in the regulation of cell polarity in vertebrates.
Thomson-scattering techniques to diagnose local electron and ion temperatures, density, and plasma wave amplitudes in laser produced plasmas (invited)
Authors: Froula D. H. , Ross J. S. , Divol L. , Glenzer S. H.
Published: October 2006

Thomson scattering has been shown to be a valuable technique for measuring the plasma conditions in laser produced plasmas. Measurement techniques that use the ion-acoustic frequency measured from the collective Thomson-scattering spectrum to extract the electron temperature, ion temperature, plasma flow, and electron density in a laser produced plasma are discussed. In a recent study [D. Froula et al., Phys. Rev. Lett. 95, 195005 (2005)], we demonstrated a novel Thomson-scattering technique that employs multiple color Thomson-scattering diagnostics to measure the dispersion of ion-acoustic fluctuations. We obtained frequency-resolved Thomson-scattering spectra of the two separate thermal ion-acoustic fluctuations with significantly different wave vectors. This new technique allows a simultaneous time resolved local measurement of electron density and temperature. The plasma fluctuations are shown to become dispersive with increasing electron temperature. Furthermore, a Thomson-scattering technique to measure the electron temperature profile is presented where recent experiments have measured a large electron temperature gradient (Te=1.4keVtoTe=3.2keV over 1.5mm) along the axis of a 2mm long Hohlraum when heated asymmetrically.
Energy dependent sensitivity of microchannel plate detectors
Authors: Rochau G. A. , Bailey J. E. , Chandler G. A. , Nash T. J. , Nielsen D. S. , Dunham G. S. , Garcia O. F. , Joseph N. R. , Keister J. W. , Madlener M. J. , Morgan D. V. , Moy K. J. , Wu M.
Published: October 2006

Understanding of microchannel plate (MCP) detectors with x-ray energy is important for applications in high energy density research such as broadband imaging and x-ray spectroscopy. The relative sensitivity with photon energy for Cu∕Au coated MCPs in the range of 250eV<hν<5000eV has been measured at the National Synchrotron Light Source. A model of this response that includes contributions from secondary photoelectron yield and interactions with multiple channels is presented. This model is shown to agree with the measured MCP response to <20% over the majority of the spectral range using cross sections determined from an independent analysis of the MCP glass composition.
Single photon ionization of van der Waals clusters with a soft x-ray laser: (SO2)n and (SO2)n(H2O)m
Authors: Dong F. , Heinbuch S. , Rocca J. J. , Bernstein E. R.
Published: October 2006

van der Waals cluster (SO2)n is investigated by using single photon ionization of a 26.5eV soft x-ray laser. During the ionization process, neutral clusters suffer a small fragmentation because almost all energy is taken away by the photoelectron and a small part of the photon energy is deposited into the (SO2)n cluster. The distribution of (SO2)n clusters decreases roughly exponentially with increasing cluster size. The photoionization dissociation fraction of I[(SO2)n−1SO+]∕I[(SO2)n+] decreases with increasing cluster size due to the formation of cluster. The metastable dissociation rate constants of (SO2)n+ are measured in the range of (0.6–1.5)×104s−1 for cluster sizes 5⩽n⩽16. Mixed SO2–H2O clusters are studied at different experimental conditions. At the condition of high SO2 concentration (20% SO2 partial pressure), (SO2)n+ cluster ions dominate the mass spectrum, and the unprotonated mixed cluster ions (SO2)nH2O+ (1⩽n⩽5) are observed. At the condition of low SO2 concentration (5% SO2 partial pressure) (H2O)nH+ cluster ions are the dominant signals, and protonated cluster ions (SO2)(H2O)nH+ are observed. The mixed clusters, containing only one SO2 or H2O molecule, SO2(H2O)nH+ and (SO2)nH2O+ are observed, respectively.
Ultralow resistance-area product of 0.4Ω(μm)2 and high magnetoresistance above 50% in CoFeB∕MgO∕CoFeB magnetic tunnel junctions
Authors: Nagamine Yoshinori , Maehara Hiroki , Tsunekawa Koji , Djayaprawira David D. , Watanabe Naoki , Yuasa Shinji , Ando Koji
Published: October 2006

An ultralow resistance-area (RA) product of 0.4Ω(μm)2 was achieved in CoFeB∕MgO∕CoFeB magnetic tunnel junctions with a high magnetoresistance ratio of 57% at room temperature. Various growth conditions for polycrystalline MgO(001) tunneling barrier were optimized to improve the crystalline orientation of the MgO(001) layer, which resulted in a significant enhancement of magnetoresistance in an ultralow RA region below 1Ω(μm)2. Removal of residual H2O molecules from a growth chamber was especially effective in improving the crystalline orientation. The present achievements will enable the development of highly sensitive read heads for ultrahigh-density hard disk drives.
γ
-ray ‘bang-time’ measurements with a gas-Cherenkov detector for inertial-confinement fusion experiments
Authors: Horsfield C. J. , Caldwell S. E. , Christensen C. R. , Evans S. C. , Mack J. M. , Sedillo T. , Young C. S. , Glebov V. Yu.
Published: October 2006

In a laser driven inertial-confinement fusion experiment, bang time is defined as the time between the laser light impinging the target and the peak of the fusion reactions. Bang time is often used to compare computed predictions to experiment. Large laser facilities, such as NIF and LMJ, which are currently under construction, will produce yields far in excess of any previous inertial-confinement fusion experiment. One of the implications of such high yields is that fusion γ rays, which have branching ratios four orders of magnitude less than that of fusion neutrons, may be used to diagnose bang time. This article describes the first of such γ-ray bang-time measurement made using the OMEGA laser facility at the Laboratory for Laser Energetics, University of Rochester. The diagnostic used for this was a gas Cherenkov detector. The experimental setup, data and error analyses, and suggested improvements are presented.
Structures and relative stability of neutral gold clusters: Aun (n=15–19)
Authors: Bulusu Satya , Zeng X. C.
Published: October 2006

We performed a global-minimum search for low-lying neutral clusters (Aun) in the size range of n=15–19 by means of basin-hopping method coupled with density functional theory calculation. Leading candidates for the lowest-energy clusters are identified, including four for Au15, two for Au16, three for Au17, five for Au18, and one for Au19. For Au15 and Au16 we find that the shell-like flat-cage structures dominate the population of low-lying clusters, while for Au17 and Au18 spherical-like hollow-cage structures dominate the low-lying population. The transition from flat-cage to hollow-cage structure is at Au17 for neutral gold clusters, in contrast to the anion counterparts for which the structural transition is at Au16− [S. Bulusu et al., Proc. Natl. Acad. Sci. U.S.A. 103, 8362 (2006)]. Moreover, the structural transition from hollow-cage to pyramidal structure occurs at Au19. The lowest-energy hollow-cage structure of Au17 (with C2v point-group symmetry) shows distinct stability, either in neutral or in anionic form. The distinct stability of the hollow-cage Au17 calls for the possibility of synthesizing highly stable core/shell bimetallic clusters M@Au17 (M=group I metal elements).
Comparison of density fluctuation measurements between O-mode and X-mode reflectometry on Tore Supra
Authors: Gerbaud T. , Clairet F. , Sabot R. , Sirinelli A. , Heuraux S. , Leclert G. , Vermare L.
Published: October 2006

Reflectometry is a versatile diagnostic which allows both electronic density profile and density fluctuation measurements. Fast sweep heterodyne technique is particularly suitable for precise measurement of the phase of the reflected signal, which records the story of the wave propagation through the plasma up to the cutoff layer, including the density fluctuations. The present article exhibits a comparison of the density fluctuation radial profile measurements between fast sweep frequency technique, both using O-mode and X-mode polarizations, and fixed frequency technique. The correct agreement between all measurements of the relative values of the density fluctuation profiles reinforces the validity of the approximations used.
Comprehensive investigation of vibrational relaxation of non-hydrogen-bonded water molecules in liquids
Authors: Seifert G. , Patzlaff T. , Graener H.
Published: October 2006

The vibrational dynamics of isolated water molecules dissolved in the nonpolar organic liquids 1,2-dichloroethane (C2H4Cl2) and d-chloroform (CDCl3) have been studied using an IR pump-probe experiment with ≈2ps time resolution. Analyzing transient, time, and spectrally resolved data in both the OH bending and the OH stretching region, the anharmonic constants of the bending overtone (v=2) and the bend-stretch combination modes were obtained. Based on this knowledge, the relaxation pathways of single water molecules were disentangled comprehensively, proving that the vibrational energy of H2O molecules is relaxing following the scheme OH stretch→OH bend overtone→OH bend→ground state. A lifetime of 4.8±0.4ps is determined for the OH bending mode of H2O in 1,2-dichloroethane. For H2O in CDCl3 a numerical analysis based on rate equations suggests a bending overtone lifetime of τ020=13±5ps. The work also shows that full 2-dimensional (pump-probe) spectral resolution with access to all vibrational modes of a molecule is required for the comprehensive analysis of vibrational energy relaxation in liquids.
Self-consistent modeling of longitudinal quantum effects in nanoscale double-gate metal oxide semiconductor field effect transistors
Authors: Heinz Frederik O. , Schenk Andreas
Published: October 2006

Ultrathin double-gate silicon-on-insulator transistors are studied in the quantum coherent limit. By treating electron-electron interaction on the level of a mean field approach, the density matrix of the device becomes diagonal when expressed in a basis that results from imposing scattering boundary conditions at the terminals. The self-consistent scattering wave functions are computed using a multisubband scattering matrix formalism. This allows us to retain the full dimensionality of the wave functions and eliminates the need for the adiabatic decomposition of the Schrödinger equation. Subband mixing is fully taken into account and a piecewise analytical representation of the wave functions can significantly reduce the number of sampling positions along transport direction. By self-consistent simulations the size of source-to-drain tunneling as a function of gate length is demonstrated for different body thicknesses. A strong forward bias is shown to increase the tunnel current due to the thinning of the source-drain potential barrier. The effect of channel orientation on the tunnel current is also discussed.
Nonergodicity of the motion in three-dimensional steep repelling dispersing potentials
Authors: Rapoport Anna , Rom-Kedar Vered
Published: October 2006

It is demonstrated numerically that smooth three degrees of freedom Hamiltonian systems that are arbitrarily close to three-dimensional strictly dispersing billiards (Sinai billiards) have islands of effective stability, and hence are nonergodic. The mechanism for creating the islands is corners of the billiards domain.
Surface-energy-driven dewetting theory of silicon-on-insulator agglomeration
Authors: Danielson David T. , Sparacin Daniel K. , Michel Jurgen , Kimerling Lionel C.
Published: October 2006

The thermal agglomeration of ultrathin (<30nm) single crystal silicon-on-insulator (SOI) films is a morphological evolution phenomenon with practical and scientific importance. This materials phenomenon represents both a critical process limitation for the fabrication of advanced ultrathin SOI-based semiconductor devices as well as a scientifically interesting morphological evolution problem. Investigations to date have attributed this phenomenon to a stress-induced morphological instability. In this paper, we demonstrate that SOI agglomeration is a surface-energy-driven dewetting phenomenon. Specifically, we propose that agglomeration occurs via a two-step surface-energy-driven mechanism consisting of (1) defect-mediated film void nucleation and (2) surface-diffusion-limited film dewetting via capillary edge and generalized Rayleigh instabilities. We show that this theory can explain all of the key experimental observations from the SOI agglomeration literature, including the locations of agglomeration initiation, the greater instability of patterned film edges, the destabilizing effect of decreasing silicon layer thickness and increasing temperature, the strikingly periodic silicon finger and island formation agglomeration morphology, and the scaling of agglomerated structure dimensions with the silicon layer thickness. General implications of this theory for the thermal stability of SOI and other common thin-film-on-insulator structures are also discussed.