bluuebunny/crossref_metadata_2025 huggingface dataset:
Crystallographic Site Distribution and Redox Activity of Fe in Nontronites Determined by Optical Spectroscopy
Authors: Merola Rose B. , McGuire Molly M.
Published: January 2010

Optical absorption spectroscopy has the potential to uncover many characteristics of Fe-bearing, redox-active smectites that have heretofore been hidden. The purpose of this study was to exploit this technique to reveal the temperature dependence of the spectra and to characterize the behavior of octahedral and tetrahedral Fe(III) under various stages of reduction. The Uley nontronites, NAu-1 and NAu-2, were compared using optical spectroscopy, which probed the crystallographic-site distribution of Fe in the clay structures as well as the resulting differences in the reduction process in the two minerals. All of the major differences in the spectra of the two minerals in the wavelength range 450–950 nm are due to the presence of a significant amount of tetrahedral Fe(III) in NAu-2.In situobservation of the optical spectra of NAu-1 suspensions as a function of the degree of reduction reveals a steady increase in the dominant intervalence charge transfer (IVCT) band and the resulting blue-green color as the Fe(II) content of the octahedral sheet increases. Although the spectrum of NAu-2 at ∼50% reduction looks nearly identical to the spectrum of NAu-1 at a similar state of reduction, the spectra corresponding to the initial stages of reduction are quite different. Stepwise reduction of NAu-2 causes a rapid decrease in the absorbance features due to crystal-field transitions of tetrahedral Fe(III) before the IVCT band appears, suggesting that tetrahedral Fe(III) is preferentially reduced before the octahedral Fe(III). The intensity of the absorbance features due to tetrahedral Fe(III) also exhibit an inverse temperature dependence, suggesting that they are enhanced due to exchange-coupling with Fe(III) ions in neighboring sites. Spectra of NAu-1 at liquid nitrogen temperature, therefore, allowed the identification of a small amount of tetrahedral Fe(III) in NAu-1 that had not been noted previously.
Realizing the cognitive potential of children 5–7 with a mathematics focus: Post‐test and long‐term effects of a 2‐year intervention
Authors: Shayer Michael. , Adhami Mundher.
Published: January 2010

Background

In the context of the British Government's policy directed on improving standards in schools, this paper presents research on the effects of a programme intended to promote the cognitive development of children in the first 2 years of primary school (Y1 & 2, aged 5–7 years). The programme is based on earlier work dealing with classroom‐based interventions with older children at both primary and secondary levels of schooling.

Aim

The hypothesis tested is that it is possible to increase the cognitive ability of children by assisting teachers towards that aim in the context of mathematics. A corollary hypothesis is that such an increase would result in an increase in long‐term school achievement.

Sample

The participants were 8 teachers in one local education authority (LEA) and 10 teachers in another. Data were analysed on 275 children present at Year 1 pre‐test in 2002 and at long‐term Key Stage 2 post‐test in 2008.

Method

Two intervention methods were employed: a Y1 set of interactive activities designed around Piagetian concrete operational schemata, and mathematics lessons in both Y1 and Y2 designed from a theory‐base derived from both Piaget and Vygotsky.

Results

At post‐test in 2004, the mean effect sizes for cognitive development of the children – assessed by the Piagetian test Spatial Relations – were 0.71 SD in one LEA and 0.60 SD in the other. Five classes achieved a median increase of 1.3 SD. The mean gains over pre‐test in 2002 for all children in Key Stage 1 English in 2004 were 0.51 SD, and at Key Stage 2 English in 2008 – the long‐term effect – were 0.36 SD, an improvement of 14 percentile points.

Conclusions

The main hypothesis was supported by the data on cognitive development. The corollary hypothesis is supported by the gains in English. The implications of this study are that relative intelligence can be increased and is not fixed, and that children can be led into collaborating with each other to the benefit of their own thinking, and that there does exist a theory‐based methodology for the improvement of teaching.
Evaluating the effectiveness of a road safety education intervention for pre‐drivers: An application of the theory of planned behaviour
Authors: Poulter Damian R. , McKenna Frank P.
Published: January 2010

Background

Young drivers are overrepresented in road traffic fatalities and collisions. Attempts to address this problem with pre‐driver education have not met with unambiguous success. However, there is a lack of research on whether pre‐driver education can change psychological antecedents to behaviour.

Aims

The framework of the theory of planned behaviour (TPB) was employed to assess the effectiveness of an educational intervention used across the UK that aims to improve attitudes to road safety in pre‐drivers.

Sample(s)

Secondary school students aged 15–16 years participated in the research, drawn from 12 schools in the UK. A total of 199 students took part in Expt 1 and 430 in Expt 2.

Method

Expt 1 employed a within‐participants design to measure any changes in road safety beliefs from pre‐ to post‐intervention and 5‐month follow‐up. Expt 2 used a between‐participants design to test whether any changes were genuine or due to experimenter effects.

Results

Results of Expt 1 revealed a small, short‐term improvement in some pre‐driver beliefs immediately following the educational intervention, but no effect on other beliefs, and some evidence of unintended outcomes. The small, significant improvements found in Expt 1 were replicated in Expt 2, which is consistent with there being a genuine effect.

Conclusions

Considering evidence from both experiments suggests the effectiveness of road safety education interventions are at best short term, and limited to some but not all psychological factors, with some risk of unintended consequences.
Newborn Screening for Galactosemia: A Review of 5 Years of Data and Audit of a Revised Reporting Approach
Authors: Freer Dennis E , Ficicioglu Can , Finegold David
Published: January 2010

Background: Availability of the galactose-1-phosphate uridyltransferase (GALT) assay for newborn (NB) screening has improved identification of classic galactosemia. Previously defined critical cutoffs for total galactose (Gal), typically 1.110 mmol/L (20 mg/dL), are still in use in laboratories measuring total Gal for the diagnosis of nonclassic galactosemias. Urgent notification/referral to a treatment center follows, although few of the NBs will need treatment.

Methods: We reviewed all NB galactosemia-screening results and their corresponding clinical outcomes over a 5-year period (first phase, 1.32 × 106 NBs) and then over a 2-year period (second phase, 274 960 NBs). Each NB was screened for Gal and GALT. When Gal was increased and/or GALT was deficient, testing for percentage galactose-1-phosphate and/or DNA testing for common GALT mutations were performed.

Results: Of 209 reported positive results, 89% did not indicate GALT deficiency. These non–GALT-deficient results represented mostly clinically benign cases with a Gal threshold of ≥1.110 mmol/L (≥20 mg/dL). The positive predictive value of a GALT cutoff of ≤40 μmol/L was 83%. After a protocol change that redefined a critical result as a GALT value ≤40 μmol/L and/or a Gal value ≥1.665 mmol/L (≥30 mg/dL), results were monitored for an additional 2 years. The new protocol dramatically reduced the number of urgent calls/referrals and reduced the total number of referrals by nearly half.

Conclusions: Use of a GALT cutoff of ≤40 μmol/L/L and a Gal cutoff of ≥1.665 mmol/L (≥30 mg/dL) for urgent notification/referral dramatically reduces false positives and unnecessary follow-up, thereby reducing the stress on healthcare resources.
Early Marketing Matters: A Time-Varying Parameter Approach to Persistence Modeling
Authors: Osinga Ernst C. , Leeflang Peter S.H. , Wieringa Jaap E.
Published: January 2010

Are persistent marketing effects most likely to appear right after the introduction of a product? The authors give an affirmative answer to this question by developing a model that explicitly reports how persistent and transient marketing effects evolve over time. The proposed model provides managers with a valuable tool to evaluate their allocation of marketing expenditures over time. An application of the model to many pharmaceutical products, estimated through (exact initial) Kalman filtering, indicates that both persistent and transient effects occur predominantly immediately after a brand's introduction. Subsequently, the size of the effects declines. The authors theoretically and empirically compare their methodology with methodology based on unit root testing and demonstrate that the need for unit root tests creates difficulties in applying conventional persistence modeling. The authors recommend that marketing models should either accommodate persistent effects that change over time or be applied to mature brands or limited time windows only.
Cultural Orientation and Brand Dilution: Impact of Motivation Level and Extension Typicality
Authors: Sharon NG
Published: January 2010

This research examines cross-cultural differences in brand dilution effects and the moderating role of motivation and extension typicality. Drawing from recent findings that indicate that culture affects the way people treat conflicting information, this research predicts that Easterners and Westerners react differently to failures by a brand extension. In contrast to previous findings that have suggested that failure in a typical extension leads to less brand dilution for Westerners when they are highly motivated (than when they are less motivated), this study argues that Easterners exhibit greater brand dilution when they are less motivated (than when they are highly motivated). The opposite pattern of results should emerge when the extension is atypical. Three studies provide support for these predictions and the underlying processes.
A Control Function Approach to Endogeneity in Consumer Choice Models
Authors: Petrin Amil , Train Kenneth
Published: January 2010

Endogeneity arises for numerous reasons in models of consumer choice. It leads to inconsistency with standard estimation methods that maintain independence between the model's error and the included variables. The authors describe a control function approach for handling endogeneity in choice models. Observed variables and economic theory are used to derive controls for the dependence between the endogenous variable and the demand error. The theory points to the relationships that contain information on the unobserved demand factor, such as the pricing equation and the advertising equation. The authors’ approach is an alternative to Berry, Levinsohn, and Pakes's (1995) product-market controls for unobserved quality. The authors apply both methods to examine households’ choices among television options, including basic and premium cable packages, in which unobserved attributes, such as quality of programming, are expected to be correlated with price. Without correcting for endogeneity, aggregate demand is estimated to be upward-sloping, suggesting that omitted attributes are positively correlated with demand. Both the control function method and the product-market controls method produce downward-sloping demand estimates that are similar.
Ties that Bind: The Impact of Multiple Types of Ties with a Customeron Sales Growth and Sales Volatility
Authors: Tuli Kapil R. , Bharadwaj Sundar G. , Kohli Ajay K.
Published: January 2010

Suppliers in business-to-business settings are increasingly building a portfolio of multiple types of ties with individual customers. For example, in addition to supplying goods and services, a supplier may have a research-and-development alliance and a marketing alliance with a customer. This study investigates the effect of multiple types of ties with a customer on a supplier's performance with the customer. The findings from panel data on supplier–customer relationships suggest that an increase in the number of different types of ties with a customer results in an increase in supplier sales to the customer and a decrease in sales volatility to that customer. The effect of a change in relationship multiplexity (i.e., number of different types of ties) on the change in sales becomes weaker and its effect on the change in sales volatility becomes stronger as the competitive intensity in the customer's industry increases. The results also indicate that the effect of a change in the number of different types of ties on the change in sales volatility becomes stronger when the intangibles intensity in a customer's industry increases. The results are robust to alternative measures, alternative estimators, heteroskedasticity, and endogeneity, among other methodological concerns. These findings have clear implications for managing multiple types of ties with a customer and indicate that relationship multiplexity is a valuable nonfinancial metric.
Retrieving Unobserved Consideration Sets from Household Panel Data
Authors: Van Nierop Erjen , Bronnenberg Bart , Paap Richard , Wedel Michel , Franses Philip Hans
Published: January 2010

The authors propose a new model to capture unobserved consideration from discrete choice data. This approach allows for unobserved dependence in consideration among brands, easily copes with many brands, and accommodates different effects of the marketing mix on consideration and choice as well as unobserved consumer heterogeneity in both processes. An important goal of this study is to establish the validity of the existing practice to infer consideration sets from observed choices in panel data. The authors show with experimental data that underlying consideration sets can be reliably retrieved from choice data alone and that consideration is positively affected by display and shelf space. Next, the model is applied to Information Resources Inc. panel data. The findings suggest that promotion effects are larger when they are included in the consideration stage of the two-stage model than in a single-stage model. The authors also find that consideration covaries across brands and that this covariation is mainly driven by unobserved consumer heterogeneity. Finally, the authors show the implications of the model for promotion planning relative to a more standard model of choice.
Recombinant manganese peroxidase (rMnP) from Pichia pastoris. Part 1: Kraft pulp delignification
Authors: Xu Haowen , Scott Gary M. , Jiang Fei , Kelly Christine
Published: January 2010

Manganese peroxidase (MnP) is the main enzyme implicated in the biobleaching of kraft pulps by white-rot fungi. However, potential commercial applications of this enzyme have been limited by its availability in large quantities. Advances have been made to produce high-yield concentrated recombinant MnP (rMnP). The objective of this study was to evaluate the ability of rMnP to delignify and brighten kraft pulps. The rMnP, produced from the yeastPichia pastoris– in high-cell density and in fed-batch fermentations – was found to be effective in lignin removal in both hardwood and softwood unbleached kraft pulps. The rMnP applied at 30 U g-1pulp for 24 h followed by alkali extraction caused significant kappa number reductions for all the pulps tested with different initial lignin contents and structures. Softwood and hardwood pulps showed similar delignification rates during rMnP treatments. Highly delignified pulps with kappa number less than 10 are less susceptible to delignification by rMnP compared with the pulps with higher lignin content. The rMnP-treated pulp was also shown to be more susceptible to subsequent peroxide bleaching compared with the control pulp. More than 60% of the kappa number reduction was achieved by sequential rMnP treatments combined with alkaline extraction. Sequential treatment with xylanase and rMnP also resulted in more extensive delignification than in each enzyme treatment alone or in the case of simultaneous application of the enzymes.
The role of hydroxyl and oxyl anion radicals in selectivity of oxygen delignification
Authors: Bouchard Jean , Wang Jie , Berry Richard
Published: January 2010

The concentration of the hydroxyl radical generated during oxygen delignification was measured with a radical trapping agent. The N,N′-(5-nitro-1,3-phenylene)-bisglutaramide (NPG) was found to be effective but the experiments revealed that at pH higher than 11.5 the anionic form of hydroxyl radical – the oxyl anion radical – causes up to four times more chain cleavage than the hydroxyl radical. It was also found that the effect of both radicals in the pulp moderated at higher partial oxygen pressure and in the presence of hemicelluloses. The implications are that selectivity can be improved by maintaining a moderate alkaline pH profile, increasing the oxygen partial pressure, and retaining hemicelluloses in the brownstock.
Fractionation, analysis, and PCA modeling of properties of four technical lignins for prediction of their application potential in binders
Authors: Gosselink Richard J.A. , van Dam Jan E.G. , de Jong Ed , Scott Elinor L. , Sanders Johan P.M. , Li Jiebing , Gellerstedt Göran
Published: January 2010

Functional properties of technical lignins need to be characterized in more detail to become a higher added value renewable raw material for the chemical industry. The suitability of a lignin from different plants or trees obtained by different technical processes can only be predicted for selected applications, such as binders, if reliable analytical data are available. In the present paper, structure dependent properties of four industrial lignins were analyzed before and after successive organic solvent extractions. The lignins have been fractionated according to their molar mass by these solvents extractions. Kraft and soda lignins were shown to have different molar mass distributions and chemical compositions. Lignin carbohydrate complexes are most recalcitrant for extraction with organic solvents. These poorly soluble complexes can consist of up to 34% of carbohydrates in soda lignins. Modeling by principle component analysis (PCA) was performed aiming at prediction of the application potential of different lignins for binder production. The lignins and their fractions could be classified in different clusters based on their properties, which are structure dependent. Kraft softwood lignins show the highest potential for plywood binder application followed by hardwood soda lignin and the fractions of Sarkanda grass soda lignin with medium molar mass. Expectedly, the softwood lignins contain the highest number of reactive sites in ortho positions to the phenolic OH group. Moreover, these lignins have a low level of impurities and medium molar mass.
Effect of helium DBD plasma treatment on the surface of wood samples
Authors: Asandulesa Mihai , Topala Ionut , Dumitrascu Nicoleta
Published: January 2010

The effects of helium dielectric barrier discharge (He-DBD) plasma treatment has been studied aiming at the preparation of wood for profitable dye covering and impregnation with an antibacterial oil. Electrical and optical emission spectroscopy measurements were performed to characterise the He-DBD discharge. The hydrophilic/hydrophobic properties of the modified surfaces were studied by dynamic contact angle measurements. The spreading area of the wet spots was also evaluated as a function of wetting time. After He-DBD plasma exposure, the adhesion properties are substantially improved and the hydrophilic character of wood surface is enhanced. The behaviour of linseed oil drops on the modified surfaces confirmed the utility of He-DBD treatment.
Reactivity of syringyl quinone methide intermediates in dehydrogenative polymerization. Part 2: pH effect in horseradish peroxidase-catalyzed polymerization of sinapyl alcohol
Authors: Tobimatsu Yuki , Takano Toshiyuki , Kamitakahara Hiroshi , Nakatsubo Fumiaki
Published: January 2010

The solvent pH effect in the horseradish peroxidase (HRP)-catalyzed polymerization of sinapyl alcohol (S-alc) and analogously, sinapyl alcohol γ-O-glucoside (isosyringin, iso-S) was investigated particularly focusing on the behavior of syringyl-type quinone methide intermediates (S-type QMs) under acidic conditions. At first, the HRP-catalyzed polymerization of iso-S at pH 6.5–2.5, which produces water-soluble dehydrogenation polymer (DHP) intermediates in a homogeneous phase, was monitored by UV spectroscopy and gel permeation chromatography with photodiode array detection (GPC-PDA). Under acidic conditions at pH below 4.5, unstablilized S-type QMs from iso-S are rapidly quenched resulting in efficient productions of DHPs, although substantial loss of HRP activity and the resulting insufficient polymerization were inevitable at pH below 3.5. In addition, it was found that a small addition of guaiacyl-type comonomer (isoconiferin, iso-G) effectively promotes the polymerization of iso-S under acidic conditions, in which the comonomer serves as a radical mediator to facilitate the HRP-catalyzed oxidations of iso-S. Next, the HRP-catalyzed polymerization of S-alc at various pH values was conducted and the resulting DHPs were characterized by GPC and NMR measurements. The yields of isolated DHPs significantly increased as solvent pH decreased below 4.5. The structural analyses of the DHPs demonstrated that reaction selectivity of S-type QMs during the polymerization drastically changed at pH below 4.5: they react efficiently with water molecules as solvent leading to the formation of benzyl alcohol type β-O-4 substructures preferentially to the formation of α-O-aryl type substructures. Consequently, the data in this study demonstrated that acidic conditions at pH below 4.5 are favored in the dehydrogenative polymerization of S-alc from the viewpoint of the reactivity of S-type QMs.
Surface properties of extracts from cork black condensate
Authors: Pires Ricardo A. , Mano João F. , Reis Rui L.
Published: January 2010

The insulation corkboard production generates black condensate (BC), a paste-like solid waste. It is hydrophobic and has the potential to be used as protective coating. To evaluate this potential, coatings were prepared from BC extracts and their surface behavior was evaluated by contact angle (CA) measurements. The CA dynamics were recorded as a function of time; advancing CAs were also registered; the approaches were applied according to Fowkes, Owens-Wendt-Rabel-Kaelble (OWRK), and Van Oss to determine the surface energy (SE) for each coating. Depending on the liquid probe, three phenomena were observed: water evaporation, diiodomethane diffusion into the coating, and rearrangement of the chemical groups on the coating surface, when glycerol was dropped onto the surface. Based on the results from the CA dynamics, the applicability of the coatings against hydrophobic environments was limited owing to its affinity to apolar compounds. The results show that the coating prepared by the toluene BC extract was the best coating. The key data were: water CA of 99.3°, total SE (between 37.4 mN m-1 and 40.1 mN m-1), SE polar component (0.1 mN m-1), and the acidic and basic characters were negligible. It can be concluded that the BC extracts have potential for coatings.
A study of water exchange in wood by means of 2D NMR relaxation correlation and exchange
Authors: Cox Julia , McDonald Peter J. , Gardiner Barry A.
Published: January 2010

Two-dimensional T
1-T
2
1H NMR relaxation correlation spectra and T
2-T
2 relaxation exchange spectra for samples of spruce wood across the full moisture content range from 0% to >100% are presented. The T
1-T
2 spectra unambiguously identify water in different environments within the wood that overlap in the corresponding and more traditional one-dimensional T
1 or T
2 experiment. The T
2-T
2 spectra unambiguously reveal the presence of water exchange between the lumen and cell wall above the fibre saturation point in sapwood. An estimate is made of the exchange rate: 1/30 to 1/3 ms-1.
A Weibull Stress Model to Predict Effects of Weld Strength Mismatch on Cleavage Fracture Toughness
Authors: Ruggieri Claudio
Published: January 2010

This work describes the development of a toughness scaling methodology incorporating the effects of weld strength mismatch on crack-tip driving forces. The approach adopts a nondimensional Weibull stress, σ¯w, as a the near-tip driving force to correlate cleavage fracture across cracked weld configurations with different mismatch conditions even though the loading parameter (measured by J or crack-tip opening displacement) may vary widely due to mismatch and constraint variations. Application of the procedure to predict the failure strain for an overmatch girth weld made of an API X80 pipeline steel demonstrates the effectiveness of the micromechanics approach. Overall, the results lend strong support to use a Weibull stress based procedure in defect assessments of structural welds.
Size Effects in Flexural Toughness of Fiber Reinforced Concrete
Authors: Jiang Zhengwu , Banthia Nemkumar
Published: January 2010

The influence of specimen size on measured flexural toughness of fiber reinforced concrete (FRC) remains largely unknown. Towards this end, an experimental program was carried out where flexural toughness tests were performed on specimens of two different sizes using ASTM C1609/C1609M-07 test procedure. Two specimen sizes of 100×100×350 mm3 and 150×150×500 mm3 were tested. A hybrid polymeric fiber at three fiber dosage rates of 3.0, 4.5, and 6.0 kg/m3 was investigated. Results indicate that the specimen size affects not only the toughness properties but also the variability in data as quantified by the coefficient of variation (COV). Size effect was more pronounced in the early part of the load-deflection curve and decreased with an increase in the fiber volume fraction. At a given fiber volume fraction, the COV, moduli of rupture, and post-crack residual strengths were all higher for the specimens of smaller size. Finally, the small size specimens showed a greater deflection hardening than the large size specimens. The last conclusion is significant in that deflection hardening is now often cited as the required performance characteristic of high performance FRC, and this property may depend more on the size of the specimens than on the composite itself.
Adaptation of Reward Sensitivity in Orbitofrontal Neurons
Authors: Kobayashi Shunsuke , Pinto de Carvalho Ofelia , Schultz Wolfram
Published: January 2010

Animals depend on a large variety of rewards but their brains have a limited dynamic coding range. When rewards are uncertain, neuronal coding needs to cover a wide range of possible rewards. However, when reward is likely to occur within a specific range, focusing the sensitivity on the predicted range would optimize the discrimination of small reward differences. One way to overcome the trade-off between wide coverage and optimal discrimination is to adapt reward sensitivity dynamically to the available rewards. We investigated how changes in reward distribution influenced the coding of reward in the orbitofrontal cortex. Animals performed an oculomotor task in which a fixation cue predicted the SD of the probability distribution of juice volumes, while the expected mean volume was kept constant. A subsequent cue specified the exact juice volume obtained for a correct saccade response. Population responses of orbitofrontal neurons that reflected the predicted juice volume showed adaptation to the reward distribution. Statistical tests on individual responses revealed that a quarter of value-coding neurons shifted the reward sensitivity slope significantly between two reward distributions, whereas the remaining neurons showed insignificant change or lack of adaptation. Adaptations became more prominent when reward distributions changed less frequently, indicating time constraints for assessing reward distributions and adjusting neuronal sensitivity. The observed neuronal adaptation would optimize discrimination and contribute to the efficient coding of a large variety of potential rewards by neurons with limited dynamic range.
Distinct Transcriptomes Define Rostral and Caudal Serotonin Neurons
Authors: Wylie Christi J. , Hendricks Timothy J. , Zhang Bing , Wang Lily , Lu Pengcheng , Leahy Patrick , Fox Stephanie , Maeno Hiroshi , Deneris Evan S.
Published: January 2010

The molecular architecture of developing serotonin (5HT) neurons is poorly understood, yet its determination is likely to be essential for elucidating functional heterogeneity of these cells and the contribution of serotonergic dysfunction to disease pathogenesis. Here, we describe the purification of postmitotic embryonic 5HT neurons by flow cytometry for whole-genome microarray expression profiling of this unitary monoaminergic neuron type. Our studies identified significantly enriched expression of hundreds of unique genes in 5HT neurons, thus providing an abundance of new serotonergic markers. Furthermore, we identified several hundred transcripts encoding homeodomain, axon guidance, cell adhesion, intracellular signaling, ion transport, and imprinted genes associated with various neurodevelopmental disorders that were differentially enriched in developing rostral and caudal 5HT neurons. These findings suggested a homeodomain code that distinguishes rostral and caudal 5HT neurons. Indeed, verification studies demonstrated that Hmx homeodomain and Hox gene expression defined an Hmx+rostral subtype and Hox+caudal subtype. Expression of engrailed genes in a subset of 5HT neurons in the rostral domain further distinguished two subtypes defined as Hmx+En+and Hmx+En−. The differential enrichment of gene sets for different canonical pathways and gene ontology categories provided additional evidence for heterogeneity between rostral and caudal 5HT neurons. These findings demonstrate a deep transcriptome and biological pathway duality for neurons that give rise to the ascending and descending serotonergic subsystems. Our databases provide a rich, clinically relevant resource for definition of 5HT neuron subtypes and elucidation of the genetic networks required for serotonergic function.
Crossing Borders in Love, War, and History: French Families during World War II
Authors: Fuchs Rachel G.
Published: January 2010

This article addresses the many borders crossed by historians and those we study. It focuses on two families involved in a custody dispute in German-occupied Paris during World War II. Sometimes freely and sometimes under duress, the family members crossed physical borders between occupied and unoccupied parts of France, and perhaps between countries. They also crossed boundaries of expected family roles, religion, and moral behavior. Anti-Jewish laws and attitudes affected their lives and options at every turn. Historians too confront boundaries of evidence: Our informed historical imagination can offer likely conclusions to the stories we tell, but, in the end, we cannot go beyond where the evidence leads us.
On Coral Reefs, Volcanoes, Gods, and Patriotic Geology; Or, James Dwight Dana Assembles the Pacific Basin
Authors: Igler David
Published: January 2010

While dozens of naturalists had examined discrete Pacific environments prior to the 1830s, the American geologist James Dwight Dana was the first to hypothesize the underlying forces that created and unified this vast ocean basin as a whole. During his four-year journey with the U.S. Exploring Expedition (1838–1842), Dana developed a holistic view of geological systems throughout the Pacific, including those continental lands soon claimed by the United States as its Far West. But Dana's innovative work on Pacific geology and his extra-continental reading of the Far West changed in the 1850s. Like other American explorer-geologists who found cause for reifying a continental geology, Dana's work lost sight of the Pacific Basin and instead focused on the exceptional and spiritually preordained structure of American landforms.
Chinos and Paisanos: Chinese Mexican Relations in the Borderlands
Authors: Lim Julian
Published: January 2010

Using the testimonio of Manuel Lee Mancilla, a Chinese Mexican man born in Mexicali in 1921, this article explores the experiences of the Chinese in northern Mexico in the early 1900s. It examines the conditions under which Chinese immigrants came to and helped build new borderland communities and simultaneously recovers the day-to-day relationships that were negotiated and nurtured there. Meaningful moments of Chinese Mexican cooperation emerged amid intense conflict and despite the anti-Chinese campaigns of the Mexican Revolution and the infamous Sonoran purges of the 1930s. Challenging static notions of ethnic and racial identities and relations, and analyzing the anti-Chinese movements in less monolithic terms, this article examines not only how Chinese and Mexicans weathered revolutionary violence and xenophobia but also the turbulent forces of U.S. capital and labor exploitation on both sides of the border.
Spud Johnson and a Gay Man's Place in the Taos Creative Arts Community
Authors: Burke Flannery
Published: January 2010

This article explores the status of Willard "Spud" Johnson within the modernist arts community of Taos, New Mexico, in the 1930s. By highlighting Johnson's entertaining and self-reflective journal, the article addresses how Johnson's homosexuality contributed to his position as a middling member of the Taos arts community, a position poised between white members of the colony, especially women, and the non-white local New Mexicans whom members of the colony patronized. By examining the internal hierarchy of the Taos arts community, I shed light on how creative production works. Although popular audiences tend to credit individual genius, the beauty of the landscape, or the appeal of local traditions for creative production, Johnson's experience suggests that internal social relationships, even inequitable ones, shape the creative dynamics of arts colonies.
Abnormal glucose tolerance in children with cystic fibrosis: the predictive role of continuous glucose monitoring system
Authors: Schiaffini Riccardo , Brufani Claudia , Russo Beatrice , Fintini Danilo , Migliaccio Antonella , Pecorelli Lia , Bizzarri Carla , Lucidi Vincenzina , Cappa Marco
Published: January 2010

A long pre-diabetic phase of abnormal glucose tolerance is described in subjects with cystic fibrosis (CF) since childhood.

Objective

The aims of the study were to compare oral glucose tolerance test (OGTT) and continuous glucose monitoring system (CGMS) in the diagnosis of altered glucose metabolism, and to longitudinally evaluate the role of CGMS in predicting glucose metabolism deterioration in children with CF.

Methods

Seventeen children with CF and 14 controls were enrolled (mean age 13.3±3.0 years). All subjects underwent OGTT and CGMS registration. On the basis of OGTT, children were classified as normal glucose tolerance, impaired glucose tolerance (IGT), IGT plus at least one glucose value above 200 mg/dl at intermediate OGTT points (IGT+200) and CF-related diabetes (CFRD). HbA1c, glucose area under the curve, insulin sensitivity, and insulinogenic and disposition indexes were also considered. Subjects with CF underwent another OGTT after 2.5 years.

Results

Baseline OGTT revealed 3/17 (7.6%) children with CF with at least one glucose value above 200 mg/dl (1 CFRD and 2 IGT+200), while CGMS revealed 6/17 (35.3%) children with glucose excursions above 200 mg/dl (P=0.010). None of the controls showed glucose over 200 mg/dl either at OGTT or at CGMS. At the 2.5-year follow-up OGTT, all the six subjects who had diabetic glucose excursion (i.e. >200 mg/dl) at baseline CGMS presented IGT+200 or CFRD. In logistic regression analysis, CGMS diabetic excursion was the strongest predictor of IGT+200 and CFRD (P<0.001).

Conclusions

CGMS could be a useful tool to predict glucose metabolism derangements in children affected by CF.
Mechanical Fabrication of Si-Ge-B Bulk Samples with Superior Thermoelectric Power
Authors: Abe Makoto , Takiguchi Hiroaki , Okamoto Yoichi , Miyazaki Hisashi , Morimoto Jun
Published: January 2010

We have already reported that Au or B doped SiGe amorphous thin films have superior thermoelectric properties which are attribute to amorphous phase. For the practical use, the bulk materials are required. In this work, we have tried and succeeded to fabricate Si-Ge-B amorphous bulk samples. First, fine particles were prepared by three kinds of mechanical process, such as roller milling method, mechanical alloying method and planetary milling method. It was intended to introduce a large amount of defects and strain into samples and/or gamorphouslization'h. Then, the prepared fine particles were pressed and formed into 2 x 5 x 15 mm^3 samples. Thermoelectric power and electrical resistivity of samples were measured by steady state measurement and four terminal method with temperature range of room temperature to 873 K in N2 flow at atmosphere pressure, respectively. Thermal conductivity was measured by photo-pyroelectric method in room temperature. Some samples have maximum value of thermoelectric power over 10-3 V/K. therefore≤ we were succeeded to prepare bulk materials which have higher thermoelectric power than that of conventional crystal materials. X-ray diffraction measurement and scanning electron microscope observation were performed on fabricated samples. From XRD measurement and SEM observation, the samples were in mixed condition of disordered microcrystals and amorphous state.
Effect of Rinkalore Mixture on the Flotation of Mupine Oxidised Ores, South DRCongo
Authors: Kabamba Ghislain Tshilombo , Mukuna Christian Muteba , Kitala Kongolo
Published: January 2010

In this study, flotation of oxidised ores rich in copper and cobalt from Mupine deposit in the Democratic Republic of Congo had been investigated. This ore contains 4.85% copper, 0.16% cobalt. The recovery of copper and cobalt was performed using flotation to increase the concentration of copper and cobalt. Flotation of the oxidized ore was performed with fatty acid type Rinkalore. Copper and cobalt present in the ore were concentrated with optimal doses of sodium silicate, Rinkalore mixture of 500 g/t, 1500 g/t respectively and optimum tall oil and pH of 23% and 9.5 respectively. The influence of Rinkalore Bioex, Rinkalore Booster Q, pH and sodium silicate on optimum operating conditions were studied. Improved performance of operating conditions was obtained with the mixture of reagents Rinkalores 10 and Booster Q. Primary feed titrating 8.70% copper and 0.31% cobalt respectively had a recovery yield of 53% and 34% respectively, and rougher concentrate titrating 8.13% copper and 0.33 % Cobalt respectively had a recovery yield of 97% and 70% respectively.
A Thermomechanical Approach to the Formation of Dark Defects in High Power Laser Diodes
Authors: Martín-Martín Alonso , Iñiguez Pilar , Jimenez Juan , Oudart Myriam , Nagle Julien
Published: January 2010

A thermomechanical model to explain the formation of dark defects in AlGaAs high power laser bars is presented. The local heating at facet defects due to nonradiative recombination and self-absorption of photons induces thermal stresses capable of producing a local plastic deformation and subsequent degradation of the device. The output power density thresholds calculated are in agreement with the data reported in the literature for these lasers.
Current Transport Mechanisms for MSM-Photodetectors on ZnO:N Thin Films
Authors: Yen Tingfang , Haungs Alan , Kim Sung Jin , Cartwright Alexander , Anderson Wayne A.
Published: January 2010

Metal-semiconductor-metal photodetectors (MSM-PDs) on ZnO:N thin films
deposited by radiofrequency (RF) sputtering and with post N+ ion implantation processing were fabricated using a ZnO/Si structure. A 10 times reduction in dark current was observed compared to the devices on an as-deposited ZnO thin film without ion implantation. These MSM-PDs gave performances of a photo-to-dark current ratio of 2030 and responsivity (R) = 2.7 A/W; the pulse response was a 12.3 ns rise time and 15.1 ns fall time using a femto-second pulse. Temperature-dependent current -voltage (I-V-T) characteristics of the MSM-PDs were observed and the space charge limited current (SCLC) theory was applied to determine the current transport mechanisms. In the SCLC region, J∼Vm gave m to determine the current transport mechanism and the value of m changes with temperatures and applied voltages. Current transport is governed by the ZnO structure rather than the electrodes.
Room Temperature Ferromagnetism in Al-doped/Al2O3-doped ZnO Film
Authors: Ma Yuwei , Ding Jun , Ran Min , Huang Xue Lian , Ng Chee Mang
Published: January 2010

In this manuscript, we study the magnetic property of Al-doped/Al2O3-doped ZnO films. We found that metallic Al-doped ZnO film shows room temperature ferromagnetism (RTFM). RTFM is correlated with the interaction of Al metallic clusters and ZnO matrix. The charge transfer has been observed between metallic Al and ZnO matrix. Therefore, RTFM in metallic Al doped ZnO may be highly probable due to charge transfer between metallic Al clusters and ZnO matrix. For Al2O3-doped ZnO film (denoted as (Zn1-x, Alx)O), RTFM was found in (Zn1-x, Alx)O film with a certain Al concentration range (16 mol%<x<50 mol%). The saturation magnetization is maximized in (Zn0.70, Al0.30)O film. The mechanism of RTFM can be explained as the interaction of ZnO nanocrystals (NCs) embedded in the amorphous phase and defects surrounding them.
Wet Chemical Etching of Zn-containing oxides and HfO2 for the fabrication of Transparent TFTs
Authors: Kim Jae-Kwan , Kim Jun Young , Han Seung-Cheol , Kwak Joon Seop , Lee Ji-Myon
Published: January 2010

The etch rate and surface morphology of Zn-containing oxide and HfO2 films after wet chemical etching were investigated. ZnO could be easily etched using each acid tested in this study, specifically sulfuric, formic, oxalic, and HF acids. The etch rate of IGZO was strongly dependent on the etchant used, and the highest measured etch rate (500 nm/min) was achieved using buffered oxide etchant at room temperature. The etch rate of IGZO was drastically increased when sulfuric acid at concentration greater than 1.5 molar was used. Furthermore, etching of HfO2 films by BF acid proceeded through lateral widening and merging of the initial irregular pits.
Magnetic properties of Fe-doped Zn-TiO2 rutile nanoparticles
Authors: Al-Omari Imaddin , Al-Harthi Salim H. , Al-Saadi Mubarak J. , Melghit Khaled
Published: January 2010

Nanoparticles Fe (x wt. %)-doped Zn-TiO2 rutile powders, with x between 0 an 10 wt. %, were prepared using a solution chemistry route based on the wet-gel stirring method. Using the TEM images we found that the powder samples exhibit nanorods and nanosheets with nanorods oriented in different directions and accompanied by an amorphous Zn on the surface. The average length of these nanorods is about 60 nm and they have an average diameter of 7 nm. The x-ray diffraction patterns revealed the formation of the nanocrystalline particles with the rutile phase, which is characterized by the (101) diffraction peak. The magnetic properties of the samples were studied using a vibrating sample magnetometer (VSM) in magnetic filed up to 13.5 kOe and in the temperature range of 100 K to 300 K. We found that the magnetization of the samples does not saturate in the maximum available field. The magnetization (M) at an applied magnetic field of 13.5 kOe is found to increase with increasing the Fe percentage at room temperature and at 100 K. TEM measurements and atomic-force microscopy (AFM) were used to image the samples.
AlN Periodic Multiple-layer Structures Grown by MOVPE for High Quality Buffer Layer
Authors: Kuryatkov Vladimir , Feng Wen , Pandikunta Mahesh , Rosenbladt Dana , Borisov Boris , Nikishin Sergey A , Holtz Mark
Published: January 2010

High crystal quality crack-free AlN on sapphire was grown by low pressure metal organic vapor phase epitaxy (MOVPE). Growth experiments combine two recent approaches: the ammonia pulse-flow method and ammonia continuous-flow growth mode by varying the V/III ratio. The detailed aspects of MOVPE, employing the periodic multilayer approach at low, intermediate, and high temperatures are described. This method yields significant reduction of screw dislocation density and provides very smooth surface for thin AlN layers.
Formation of Antibody Microarrays on Aluminum Nitride Surface Using Patterned Organosilane Self-Assembled Monolayers
Authors: Chiu Chi-Shun , Lee Hong-Mao , Gwo Shangjr
Published: January 2010

Surface biofunctionalization of group-III nitride semiconductors has recently attracted much interest due to their biocompatibility, nontoxicity, and long-term chemical stability under demanding physiochemical conditions for chemical and biological sensing. Among III-nitrides, aluminum nitride (AlN) and aluminum gallium nitride (AlGaN) are particularly important because they are often used as the sensing surfaces for sensors based on field-effect transistor or surface acoustic wave sensor structures. Patterned self-assembled monolayer (SAM) templates are composed of two types of organosilane molecules terminated with different functional groups (amino and methyl), which were fabricated on AlN/sapphire substrates by combining photolithography, lift-off process, and self-assembly technique. Clear imaging contrast of SAM micropatterns can be observed by field emission scanning electron microscopy (FE-SEM) operating at a low accelerating voltage in the range of 0.5–1.5 kV. In this work, the formation of green fluorescent protein (GFP) antibody microarrays was demonstrated by the specific protein binding of enhanced GFP (EGFP) labeling. The observed strong fluorescent signal from antibody functionalized regions on the SAM-patterned AlN surface indicates the retained biological activity of specific molecular recognition resulting from the antibody–EGFP interaction. The results reported here show that micropatterning of organosilane SAMs by the combination of photolithographic process and lift-off technique is a practical approach for the fabrication of reaction regions on AlN-based bioanalytical microdevices.
Influence of Hydrogen on Growth of Carbon Nanotubes
Authors: Belov Maxim , Knizhnik Andrey , Lebedeva Irina , Gavrikov Alexey , Potapkin Boris , Sommerer Timothy , Eastman Chris
Published: January 2010

The influence of hydrogen on the growth of carbon nanostructures in thermal chemical vapor deposition is studied using density functional theory calculations. It is shown that hydrogen adatoms effectively bind to edges of graphitic structures on the Ni (111) surface. This is found to result in a significant decrease of the rate of carbon attachment to the growing graphitic structures. However, it is also demonstrated that the edges of graphitic structures which are attached to steps on the Ni surface should not be hydrogenated.
Enhanced long-term stability of functionalized silicon nanoparticles using esters
Authors: Gupta Anoop , Kluge Sebastian , Schulz Christof , Wiggers Hartmut
Published: January 2010

The surface of freshly etched silicon nanoparticles (Si-NPs) was covalently bonded with alkyl groups and esters via thermally induced hydrosilylation. The surface chemistry of functionalized Si-NPs was analyzed at different air exposure time by means of Fourier transform infrared spectroscopy (FTIR). We observed that the stability of functionalized Si-NPs significantly depends on the type of organic ligands attached to their surface. Ester-terminated Si-NPs exhibit higher stability compared to that are bonded with alkyl groups. We show that the use of esters with large spatial configuration causes a lower surface coverage of Si-NPs but at the same time offers better protection against surface oxidation.