bluuebunny/crossref_metadata_2025 huggingface dataset:
Strychnine, but not PMBA, inhibits neuronal nicotinic acetylcholine receptors expressed by rabbit retinal ganglion cells
Authors: RENNA J.M. , STRANG C.E. , AMTHOR F.R. , KEYSER K.T.
Published: September 2007

Strychnine is considered a selective competitive antagonist of glycine gated Cl−channels (Saitoh et al., 1994) and studies have used strychnine at low micromolar concentrations to study the role of glycine in rabbit retina (Linn, 1998; Protti et al., 2005). However, other studies have shown that strychnine, in the concentrations commonly used, is also a potent competitive antagonist of α7 nicotinic acetylcholine receptors (nAChRs; Matsubayashi et al., 1998). We tested the effects of low micromolar concentrations of strychnine and 3-[2′-phosphonomethyl[1,1′-biphenyl]-3-yl] alanine (PMBA), a specific glycine receptor blocker (Saitoh et al., 1994; Hosie et al., 1999) on the activation of both α7 nAChRs on retinal ganglion cells and on ganglion cell responses to a light flash. Extracellular recordings were obtained from ganglion cells in an isolated retina/choroid preparation and 500 μM choline was used as an α7 agonist (Alkondon et al., 1997). We recorded from brisk sustained and brisk transient OFF cells, many of which have been previously shown to have α7 receptors (Strang et al., 2005). Further, we tested the effect of strychnine, PMBA and α-bungarotoxin on the binding of tetramethylrhodamine α-bungarotoxin in the inner plexiform layer. Our data indicates that strychnine, at doses as low as 1.0 μM, can inhibit the α7 nAChR-mediated response to choline, but PMBA at concentrations as high as 0.4 μM does not. Binding studies show strychnine and α-bungarotoxin inhibit binding of labeled α-bungarotoxin in the IPL. Thus, the effects of strychnine application may be to inhibit glycine receptors expressed by ganglion cell or to inhibit amacrine cell α7 nAChRs, both of which would result in an increase in the ganglion cell responses. Further research will be required to disentangle the effects of strychnine previously believed to be caused by a single mechanism of glycine receptor inhibition.
Farmers’ Cooperatives in Bavaria, 1880–1914: ‘State-Help’ and ‘Self-Help’ in Imperial Germany
Authors: FARR IAN
Published: September 2007

This paper examines the growth of peasant/farmer cooperatives in the German state of Bavaria in the years circa 1880–1914. The remarkable increase in the number of cooperative ventures in rural Germany, seen most clearly in the proliferation of credit cooperatives (Raiffeisenvereine), has attracted scant attention from historians. This study of the phenomenon in Bavaria suggests that the longer-term structural problems of peasant agriculture, compounded by seasonal crises and the absence of adequate structures of credit for small producers, all helped to make peasant farmers more receptive to cooperative innovation. In addition, however, state encouragement, galvanised in no small measure by the marked and, for the Bavarian state, discomfiting politicisation of agrarian interests in the early 1890s, was also instrumental in the extension of the cooperative idea. Certainly the more demagogic agrarian lobbies of the period, whether in Bavaria or in Germany as a whole, protested loudly that self-help measures such as cooperative credit, purchase and sales counted for relatively little, and that the only sure protection for farmers in the face of rapidly changing market conditions was large-scale state subvention, above all in the form of higher tariffs. However, the evidence presented here suggests that political demands to insulate the peasantry from change in fact formed part of a critical interplay between agrarian mobilisation, state intervention and cooperative initiatives whose effects, even if difficult to calculate exactly, undoubtedly contributed to the improvements in peasant farming in this period.
Squire and Community: T.G. Dixon at Holton-le-Moor, 1906–1937
Authors: OLNEY RICHARD
Published: September 2007

This article looks at a small English rural estate, and at the role of its squire, in the early twentieth century. It describes the estate, parish and village of Holton-le-Moor as inherited by the Reverend T.G. Dixon in 1906, and assesses his impact on all three areas of local society during the following thirty years. Although he was a conscientious landlord and a devoted churchman, his most lasting influence was on the life of the village. Both conservative and progressive in his views, his inconsistencies reflected a rural society in transition; but, especially in providing a village hall in 1910, he anticipated and facilitated post-First World War developments in the structure of village life. Relations between the rural aristocracy and its dependents have often been described in terms of paternalism on the one hand and deference on the other. This article suggests that ideas of community may sometimes be more useful when considering the dealings of a small squire with his villagers.
The Distribution of Patterns in Random Trees
Authors: CHYZAK FRÉDÉRIC , DRMOTA MICHAEL , KLAUSNER THOMAS , KOK GERARD
Published: September 2007

Let$\Tn{}$denote the set of unrooted labelled trees of sizenand let ℳ be a particular (finite, unlabelled) tree. Assuming that every tree of$\Tn{}$is equally likely, it is shown that the limiting distribution asngoes to infinity of the number of occurrences of ℳ is asymptotically normal with mean value and variance asymptotically equivalent toμnand σ2n, respectively, where the constants μ>0 and σ≥0 are computable.
Adiponectin, the controversial hormone
Authors: Garaulet Marta , Hernández-Morante Juan J , de Heredia Fátima Pérez , Tébar Francisco J
Published: September 2007

Objective

To discuss present knowledge about adiponectin hormone.

Design

Review of existing literature.

Setting and results

Adiponectin is one of the most interesting cytokines associated with obesity, although its physiological role remains to be fully clarified. Adiponectin is a 247-amino acid protein that contains four differentiable domains. Contrary to most adipose-related cytokines, adiponectin levels are surprisingly lower in obese than in lean humans. Women have been found to have significantly higher adiponectin plasma concentrations than men. Further research is needed in order to identify new polymorphisms which contribute to explain the potential role of adiponectin in obesity and related pathologies.

Considering the anti-inflammatory properties of adiponectin and the fact that it is negatively associated with adiposity, this cytokine could be one of the links between obesity and inflammation. The main mechanisms of action of adiponectin are directed to a protective role against atherogenic and insulin resistance processes. Research has revealed interesting new functions far beyond metabolism, such as immunity, cancer and bone formation.

Contrary to all adipose-related proteins, adiponectin decreases with obesity. Most of the contradictory data surrounding adiponectin are related to plasma values and their relationship with body fat, gender differences and insulin resistance. There are important confounding results regarding the mechanisms of action and functions of adiponectin, especially in relation to insulin resistance and inflammation.
Obesity and cardiovascular disease
Authors: Pérez Pérez Antonio , Ybarra Muñoz Juan , Blay Cortés Vicente , de Pablos Velasco Pedro
Published: September 2007

Background

The prevalence of obesity has reached epidemic proportions, and in terms of the extent of its negative impact on the health has been compared to those of tobacco and alcohol. One of the first medical consequences of obesity to be recognised was cardiovascular disease (CVD). Obesity, particularly abdominal obesity, predisposes a person to a number of other cardiovascular risk factors, and is an independent predictor of clinical CVD including coronary death, coronary heart disease, heart failure and stroke.

Materials and methods

A Medline search using the following keywords (obesity, cardiovascular disease, body mass index, cardiovascular risk factors, type 2 diabetes, metabolic syndrome) was performed looking for high impact factor English-written references.

Results

Ninety-nine (N=99) relevant articles published in the last 15 years were selected and commented. As detailed throughout the text, current therapies available for weight management can improve or prevent many of these obesity-related risk factors for CVD. However, there is some controversy as to whether weight loss is beneficial for health, and large clinical outcome trials such as the Look-AHEAD (Action for Health in Diabetes) trial or the SCOUT (Sibutramine Cardiovascular Outcomes Trial) study are currently ongoing.

Discussion

In the present review, we summarise the effects of obesity as well as the efficacy of weight-loss interventions on cardiovascular risk factors and CVD.
Does the prevalence of the metabolic syndrome improve by applying the International Diabetes Federation criteria?
Authors: Soto González A , Bellido Guerrero D , Buño Soto M , Pértega Díaz S , De Luis D , Lopez de la Torre M , Martínez Olmos M
Published: September 2007

Objective

To estimate the prevalence of the metabolic syndrome (MS) in a population of patients with overweight and obesity of the A Coruña and Granada health areas, using the definitions of the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (ATP III) and of the International Diabetes Federation (IDF).

Patients and methods

During a period extending from 1996 to 2003, only those patients attending endocrinology outpatient clinics for whom all the anthropometric and biochemical parameters used to define the MS, both according to the ATP IIII and the IDF, were available were selected. The final study sample consisted of 285 patients, 198 females (69.5%) and 87 males (30.5%).

Results

The prevalence of the MS was 29.8% when the ATP III definition was applied, and 41.1% according to the IDF criteria. Prevalence by sex was 32.2% in men and 28.8% in women according to the ATP III, and 42.5% and 40.4%, respectively, according to the IDF.

Conclusions

In a patient population with overweight or obesity, the prevalence of the MS is higher when the IDF criteria, instead of the ATP III criteria, are used. These findings may have significant implications when it comes to addressing early diagnosis of cardiovascular disease and diabetes mellitus in these patients, in order to perform therapeutic measures at the initial stages and thereby reduce metabolic and cardiovascular complications.
Application of Focused Ion Beam to Atom Probe Tomography Specimen Preparation from Mechanically Alloyed Powders
Authors: Choi Pyuck-Pa , Al-Kassab Tala'at , Kwon Young-Soon , Kim Ji-Soon , Kirchheim Reiner
Published: September 2007

Focused ion-beam milling has been applied to prepare needle-shaped atom probe tomography specimens from mechanically alloyed powders without the use of embedding media. The lift-out technique known from transmission electron microscopy specimen preparation was modified to cut micron-sized square cross-sectional blanks out of single powder particles. A sequence of rectangular cuts and annular milling showed the highest efficiency for sharpening the blanks to tips. First atom probe results on a Fe95Cu5powder mechanically alloyed in a high-energy planetary ball mill for 20 h have been obtained. Concentration profiles taken from this powder sample showed that the Cu distribution is inhomogeneous on a nanoscale and that the mechanical alloying process has not been completed yet. In addition, small clusters of oxygen, stemming from the ball milling process, have been detected. Annular milling with 30 keV Ga ions and beam currents ≥50 pA was found to cause the formation of an amorphous surface layer, whereas no structural changes could be observed for beam currents ≤10 pA.
On the Structural Diversity of Sialoliths
Authors: de Matos António P. Alves , Carvalho Patrícia A. , Almeida Arlindo , Duarte Luís , Vilar Rui , Leitão Jorge
Published: September 2007

Sialoliths from parotid and submaxillar glands have been characterized. Fractured and polished surfaces revealed an intrinsic structural diversity across the calculi sections. In general, the calculi presented highly mineralized amorphous-looking cores surrounded by concentric alternating mineralized and organic layers. The thickness of these layers decreased from the outer regions toward the center of the sialolith, illustrating a sequence of growth stages. Nevertheless, a significant variability could be detected among the specimens. In some cases, the calculi displayed multiple cores and lacked concentric laminated structures. In other instances, the specimens exhibited extensive regions of globular structures. In these cases, the globule diameter decreased across the radius toward the center of the sialoliths, and the globular structures tended to reorganize, forming bright and dark laminated layers surrounding the core. The participation of globular structures in the layer formation process points to morphogenetic mechanisms not previously described.
Challenges in Nonlinear Structural Equation Modeling
Authors: Dimitruk Polina , Schermelleh-Engel Karin , Kelava Augustin , Moosbrugger Helfried
Published: September 2007

Abstract. Challenges in evaluating nonlinear effects in multiple regression analyses include reliability, validity, multicollinearity, and dichotomization of continuous variables. While reliability and validity issues are solved by employing nonlinear structural equation modeling, multicollinearity remains a problem which may even be aggravated when using latent variable approaches. Further challenges of nonlinear latent analyses comprise the distribution of latent product terms, a problem especially relevant for approaches using maximum likelihood estimation methods based on multivariate normally distributed variables, and unbiased estimates of nonlinear effects under multicollinearity. The only methods that explicitly take the nonnormality of nonlinear latent models into account are latent moderated structural equations (LMS) and quasi-maximum likelihood (QML). In a small simulation study both methods yielded unbiased parameter estimates and correct estimates of standard errors for inferential statistics. The advantages and limitations of nonlinear structural equation modeling are discussed.
An evaluation of reaction probabilities of sulfate and nitrate precursors onto East Asian dust particles
Authors: Song Chul H. , Kim Chung M. , Lee Yoo J. , Carmichael Gregory R. , Lee Bo K. , Lee Dong S.
Published: September 2007

We investigate the chemical evolution of dust particles and examine the magnitudes of reaction probability (γ) of sulfate and nitrate precursors (such as H2SO4, SO2, N2O5, and HNO3) onto dust particles in East Asia. For this investigation, three data sets from ACE‐Asia U.S. National Science Foundation (NSF) C130 flights 6, 7, and 8 and three data sets from measurements in Seoul were analyzed. During the selected dust storm periods, large amounts of CO32− still remained in fine‐mode dust particles (Dp < ∼1.3 μm). The average fractions of CO32− (based on [Ca2+] + [Mg2+] equivalences) for the three C130 flights were 0.87, 0.68, and 0.39, respectively, and the average CO32− fractions for the three data sets in Seoul ranged from 0.43 to 0.86. The degrees of chemical evolution of mineral dust indicated by the CO32− fractions were significantly smaller than those reported in previous dust chemistry transport modeling studies conducted with the assumption of aerosol internal mixing. Our analysis suggests that this could be due to the use of excessively high γ values in the model simulations, as further confirmed in this study with Lagrangian photochemical model simulations conducted with both the constraints observed by ACE‐Asia C130 flights and the initial concentrations obtained by U.S.‐EPA Models‐3/Community Multi‐scale Air Quality (CMAQ) modeling over East Asia. It is also found in this study that the magnitudes of γs are closely related with aerosol mixing state. In order to confirm this we conducted Lagrangian model simulations for an example case under the assumption of aerosol external mixing. Under this assumption the formations of sulfate and nitrate on/in fine‐mode mineral dust are greatly limited because of small γs onto mineral dust (γDust) and low precursor concentrations. However, it is also recommended that for more precise evaluations of γDust, a more sophisticated Lagrangian type of photochemical modeling is necessary. In addition, in this study a possible dependence of the γ values on relative humidity (RH) is also investigated. On the basis of our analysis we suggest that particular attention should be paid to the issue of the RH‐dependent γ in future dust chemistry transport modeling studies with the issue of aerosol mixing state.
Sensitivity and response of beryllium‐10 in marine sediments to rapid production changes (geomagnetic events): A box model study
Authors: Christl Marcus
Published: September 2007

The response and the sensitivity of the marine beryllium‐10 flux to abrupt production changes (e.g., caused by a geomagnetic event) are investigated by using a simple box model. The effect of mixing processes in the water column on the 10Be flux is simulated, and the influence of bioturbation on the sedimentary record is studied. While the effect of the oceanic residence time is found to be small, bioturbation can drastically change the shape and the amplitude of the modeled 10Be peak. The simulations indicate that 10Be production peaks persisting for more than 1500 years are recorded well in deep‐sea sediments if bioturbation‐induced integration times are small (tbio ≤ 1000 years), while sediment cores with tbio ≥ 1000 years are found to be not well suited for stratigraphic purposes. The results further show that the sedimentary 10Be peak lags initial signal. This time lag is almost independent of the event duration (for tbio ≤ 1000 years), ranging between about 400 and 600 years. Therefore the model results support the idea that marine 10Be peaks corresponding to geomagnetic events can be used as a global time marker to match marine, terrestrial, and ice core chronologies on the millennial and (if the time lag of (500 ± 100) years is considered) the submillennial timescale.
Noise‐induced phenomena in riparian vegetation dynamics
Authors: Camporeale C. , Ridolfi L.
Published: September 2007

Random forcing due to the river streamflow is a key element in riparian vegetation ecosystems. It influences several aspects of the riparian landscape, the most important being the morphology and water availability. In this letter, we analytically solve a stochastic model to show how hydrological random fluctuations are able to induce both statistically stable states and bimodality in vegetation behavior. These noise‐induced results can contribute to explain two well‐documented features of several riparian landscapes: the bell‐shaped biomass distribution along riparian transects, and spatial vegetation patchiness along a river.
Mitochondrial oxygen sensing: regulation of hypoxia-inducible factor by mitochondrial generated reactive oxygen species
Authors: Bell Eric L. , Chandel Navdeep S.
Published: September 2007

Decreased oxygen availability (hypoxia) promotes physiological processes such as energy metabolism, angiogenesis, cell proliferation and cell viability through the transcription factor HIF (hypoxia-inducible factor). Activation of HIF can also promote pathophysiological processes such as cancer and pulmonary hypertension. The mechanism(s) by which hypoxia activates HIF are the subject of intensive research. In this chapter we outline the model in which mitochondria regulate the stability of HIF through the increased production of ROS (reactive oxygen species) during hypoxia.
Hypoxic pulmonary vasoconstriction
Authors: Evans A. Mark
Published: September 2007

HPV (hypoxic pulmonary vasoconstriction) is the critical and distinguishing characteristic of the arteries that feed the lung. In marked contrast, systemic arteries dilate in response to hypoxia to meet the metabolic demands of the tissues they supply. Physiologically, HPV contributes to ventilation–perfusion matching in the lung by diverting blood flow to oxygen-rich areas. However, when alveolar hypoxia is global, as in diseases such as emphysema and cystic fibrosis, HPV leads to HPH (hypoxic pulmonary hypertension) and right heart failure. HPV is driven by the intrinsic response to hypoxia of two different cell types, namely the pulmonary arterial smooth muscle and endothelial cells. These are representatives of a group of specialized cells, commonly referred to as oxygen-sensing cells, which are defined by their acute sensitivity to relatively small changes in PO2 and have evolved to monitor oxygen supply and alter respiratory and circulatory function, as well as the capacity of the blood to transport oxygen. Upon exposure to hypoxia, mitochondrial oxidative phosphorylation is inhibited in all such cells and this, in part, mediates cell activation. In the case of pulmonary arteries, constriction is triggered via: (i) calcium release from the smooth muscle sarcoplasmic reticulum and consequent store-depletion-activated calcium entry into the smooth muscle cells and, (ii) the modulation of transmitter release from the pulmonary artery endothelium, which leads to further constriction of the smooth muscle by increasing the sensitivity of the contractile apparatus to calcium.
Analogous and Distinctive Patterns of Prelinguistic Communication in Toddlers With and Without Hearing Loss
Authors: Zaidman-Zait Anat , Dromi Esther
Published: September 2007

Purpose

This study was conducted to compare the prelinguistic communicative abilities of toddlers with hearing loss and without hearing loss during the 2nd year of life and shortly before the emergence of productive single-word lexicons.

Method

The participants were 28 toddlers with hearing loss who participated in an early intervention program and 92 toddlers with normal hearing at similar language levels and close chronological ages. The assessment consisted of the Hebrew Parent Questionnaire—Communication and Early Language (HPQ-CEL; E. Dromi, H. Ben-Shahar-Treitel, E. Guralnik, & D. Ringwald-Frimerman, 1992) that guided parents' observations of their toddlers in 6 contexts at home. Parents reported on a range of prelinguistic communicative abilities.

Results

Profile analysis indicated that the 2 groups used a remarkably similar overall profile of prelinguistic behaviors. Interrelationships among behaviors were noticeably similar, too. Two communication properties unique to toddlers with hearing loss were relatively lower spontaneous use of words and reduced involvement in triadic book reading interactions. In addition, the associations between use of words and gestures in toddlers with hearing loss were slightly different from the toddlers with normal hearing, and the range of innovative gestures that they produced was greater.

Conclusion

The remarkable similarity between the 2 groups support the feasibility of adopting goals and principles known to hold true in typical development for fostering communication in toddlers with hearing loss.
Language Acquisition With Limited Input: Romanian Institution and Foster Care
Authors: Windsor Jennifer , Glaze Leslie E. , Koga Sebastian F. ,   The Bucharest Early Intervention Project Core Group
Published: September 2007

Purpose

To provide the first detailed information about native language abilities of children who are or had been institutionalized.

Method

The language of ten 30-month-old children raised in Romanian orphanages was compared with that of 30 chronological-age-matched peers: 10 children who had moved recently from orphanages to foster care, 10 children in foster families for at least 1 year, and 10 children raised in their biological families. Ten language measures were obtained from communication during play and from parent/caregiver report.

Results

Children who were institutionalized and children in foster care for a brief time showed substantial language delays, with some of these children not yet producing intelligible words. Children in foster care for at least 1 year approximated the expressive output and receptive language of children who had never been institutionalized; however, they showed lower expressive grammatical abilities. Within the group of children who were institutionalized, the presence of a preferred caregiver and a measure of development, greater height, were associated with greater language output. Although children in orphanages produced fewer complex forms than children in biological families, there were no systematic qualitative differences in language structure across groups.

Conclusion

Foster care facilitated language growth after substantial language delays associated with institutionalization.
Simple sequence repeat markers associated with three quantitative trait loci for black point resistance can be used to enrich selection populations in bread wheat
Authors: Christopher M. J. , Williamson P. M. , Michalowitz M. , Jennings R. , Lehmensiek A. , Sheppard J. , Banks P.
Published: September 2007

Black point in wheat has the potential to cost the Australian industry $A30.4 million a year. It is difficult and expensive to screen for resistance, so the aim of this study was to validate 3 previously identified quantitative trait loci (QTLs) for black point resistance on chromosomes 2B, 4A, and 3D of the wheat variety Sunco. Black point resistance data and simple sequence repeat (SSR) markers, linked to the resistance QTLs and suited to high-throughput assay, were analysed in the doubled haploid population, Batavia (susceptible) × Pelsart (resistant). Sunco and Pelsart both have Cook in their pedigree and both have the Triticum timopheevii translocation on 2B. SSR markers identified for the 3 genetic regions were gwm319 (2B, T. timopheevii translocation), wmc048 (4AS), and gwm341 (3DS). Gwm319 and wmc048 were associated with black point resistance in the validation population. Gwm341 may have an epistatic influence on the trait because when resistance alleles were present at both gwm319 and wmc048, the Batavia-derived allele at gwm341 was associated with a higher proportion of resistant lines. Data are presented showing the level of enrichment achieved for black point resistance, using 1, 2, or 3 of these molecular markers, and the number of associated discarded resistant lines. The level of population enrichment was found to be 1.83-fold with 6 of 17 resistant lines discarded when gwm319 and wmc048 were both used for selection. Interactions among the 3 QTLs appear complex and other genetic and epigenetic factors influence susceptibility to black point. Polymorphism was assessed for these markers within potential breeding material. This indicated that alternative markers to wmc048 may be required for some parental combinations. Based on these results, marker-assisted selection for the major black point resistance QTLs can increase the rate of genetic gain by improving the selection efficiency and may facilitate stacking of black point resistances from different sources.
Weak response of oceanic dimethylsulfide to upper mixing shoaling induced by global warming
Authors: Vallina S. M. , Simó R. , Manizza M.
Published: September 2007

The solar radiation dose in the oceanic upper mixed layer (SRD) has recently been identified as the main climatic force driving global dimethylsulfide (DMS) dynamics and seasonality. Because DMS is suggested to exert a cooling effect on the earth radiative budget through its involvement in the formation and optical properties of tropospheric clouds over the ocean, a positive relationship between DMS and the SRD supports the occurrence of a negative feedback between the oceanic biosphere and climate, as postulated 20 years ago. Such a natural feedback might partly counteract anthropogenic global warming through a shoaling of the mixed layer depth (MLD) and a consequent increase of the SRD and DMS concentrations and emission. By applying two globally derived DMS diagnostic models to global fields of MLD and chlorophyll simulated with an Ocean General Circulation Model coupled to a biogeochemistry model for a 50% increase of atmospheric CO2and an unperturbed control run, we have estimated the response of the DMS-producing pelagic ocean to global warming. Our results show a net global increase in surface DMS concentrations, especially in summer. This increase, however, is so weak (globally 1.2%) that it can hardly be relevant as compared with the radiative forcing of the increase of greenhouse gases. This contrasts with the seasonal variability of DMS (1000–2000% summer-to-winter ratio). We suggest that the “plankton–DMS–clouds–earth albedo feedback” hypothesis is less strong a long-term thermostatic system than a seasonal mechanism that contributes to regulate the solar radiation doses reaching the earth's biosphere.
Structural diversity in twin-arginine signal peptide-binding proteins
Authors: Maillard Julien , Spronk Chris A. E. M. , Buchanan Grant , Lyall Verity , Richardson David J. , Palmer Tracy , Vuister Geerten W. , Sargent Frank
Published: September 2007

The twin-arginine transport (Tat) system is dedicated to the translocation of folded proteins across the bacterial cytoplasmic membrane. Proteins are targeted to the Tat system by signal peptides containing a twin-arginine motif. In
Escherichia coli
, many Tat substrates bind redox-active cofactors in the cytoplasm before transport. Coordination of cofactor insertion with protein export involves a “Tat proofreading” process in which chaperones bind twin-arginine signal peptides, thus preventing premature export. The initial Tat signal-binding proteins described belonged to the TorD family, which are required for assembly of
N
- and
S
-oxide reductases. Here, we report that
E. coli
NapD is a Tat signal peptide-binding chaperone involved in biosynthesis of the Tat-dependent nitrate reductase NapA. NapD binds tightly and specifically to the NapA twin-arginine signal peptide and suppresses signal peptide translocation activity such that transport via the Tat pathway is retarded. High-resolution, heteronuclear, multidimensional NMR spectroscopy reveals the 3D solution structure of NapD. The chaperone adopts a ferredoxin-type fold, which is completely distinct from the TorD family. Thus, NapD represents a new family of twin-arginine signal-peptide-binding proteins.
Whole-ecosystem study shows rapid fish-mercury response to changes in mercury deposition
Authors: Harris Reed C. , Rudd John W. M. , Amyot Marc , Babiarz Christopher L. , Beaty Ken G. , Blanchfield Paul J. , Bodaly R. A. , Branfireun Brian A. , Gilmour Cynthia C. , Graydon Jennifer A. , Heyes Andrew , Hintelmann Holger , Hurley James P. , Kelly Carol A. , Krabbenhoft David P. , Lindberg Steve E. , Mason Robert P. , Paterson Michael J. , Podemski Cheryl L. , Robinson Art , Sandilands Ken A. , Southworth George R. , St. Louis Vincent L. , Tate Michael T.
Published: September 2007

Methylmercury contamination of fisheries from centuries of industrial atmospheric emissions negatively impacts humans and wildlife worldwide. The response of fish methylmercury concentrations to changes in mercury deposition has been difficult to establish because sediments/soils contain large pools of historical contamination, and many factors in addition to deposition affect fish mercury. To test directly the response of fish contamination to changing mercury deposition, we conducted a whole-ecosystem experiment, increasing the mercury load to a lake and its watershed by the addition of enriched stable mercury isotopes. The isotopes allowed us to distinguish between experimentally applied mercury and mercury already present in the ecosystem and to examine bioaccumulation of mercury deposited to different parts of the watershed. Fish methylmercury concentrations responded rapidly to changes in mercury deposition over the first 3 years of study. Essentially all of the increase in fish methylmercury concentrations came from mercury deposited directly to the lake surface. In contrast, <1% of the mercury isotope deposited to the watershed was exported to the lake. Steady state was not reached within 3 years. Lake mercury isotope concentrations were still rising in lake biota, and watershed mercury isotope exports to the lake were increasing slowly. Therefore, we predict that mercury emissions reductions will yield rapid (years) reductions in fish methylmercury concentrations and will yield concomitant reductions in risk. However, a full response will be delayed by the gradual export of mercury stored in watersheds. The rate of response will vary among lakes depending on the relative surface areas of water and watershed.
Space flight alters bacterial gene expression and virulence and reveals a role for global regulator Hfq
Authors: Wilson J. W. , Ott C. M. , zu Bentrup K. Höner , Ramamurthy R. , Quick L. , Porwollik S. , Cheng P. , McClelland M. , Tsaprailis G. , Radabaugh T. , Hunt A. , Fernandez D. , Richter E. , Shah M. , Kilcoyne M. , Joshi L. , Nelman-Gonzalez M. , Hing S. , Parra M. , Dumars P. , Norwood K. , Bober R. , Devich J. , Ruggles A. , Goulart C. , Rupert M. , Stodieck L. , Stafford P. , Catella L. , Schurr M. J. , Buchanan K. , Morici L. , McCracken J. , Allen P. , Baker-Coleman C. , Hammond T. , Vogel J. , Nelson R. , Pierson D. L. , Stefanyshyn-Piper H. M. , Nickerson C. A.
Published: September 2007

A comprehensive analysis of both the molecular genetic and phenotypic responses of any organism to the space flight environment has never been accomplished because of significant technological and logistical hurdles. Moreover, the effects of space flight on microbial pathogenicity and associated infectious disease risks have not been studied. The bacterial pathogen
Salmonella typhimurium
was grown aboard Space Shuttle mission STS-115 and compared with identical ground control cultures. Global microarray and proteomic analyses revealed that 167 transcripts and 73 proteins changed expression with the conserved RNA-binding protein Hfq identified as a likely global regulator involved in the response to this environment. Hfq involvement was confirmed with a ground-based microgravity culture model. Space flight samples exhibited enhanced virulence in a murine infection model and extracellular matrix accumulation consistent with a biofilm. Strategies to target Hfq and related regulators could potentially decrease infectious disease risks during space flight missions and provide novel therapeutic options on Earth.
Code switching and identity in the discourse of Catalan immigrants in Mexico
Authors: Curcó Carmen
Published: September 2007

This paper analyzes patterns of code switching found in a small group of first and second generation Catalan immigrants in Mexico, and is part of a wider study on the impact of exile upon the construction of identity in the discourse of political immigrants in Latin America. With regard to the pragmatic exploitation of code switching, it argues that code switching is used by bilinguals even when a monolingual alternative is available, either because changing languages at a specific point in conversation reduces the processing effort involved in interpreting the stretch of discourse where the switch occurs, or because the shift of code adds cognitive effects to the overall interpretation of the message. The paper focuses on the effects of ad hoc concept construction, — a well studied phenomenon in monolingual discourse — on the presentation of self in bilingual discourse, analyzing cases when the pragmatically derived ad hoc concept involves a switch of codes. It is argued that this mechanism helps subjects represent themselves in bilingual conversation as distinct both from Mexicans and from non expatriate Catalans.
Critical thinking in reflective sessions and in online interactions
Authors: Celani Maria Antonieta Alba , Collins Heloisa
Published: September 2007

This paper focuses on online educational sessions of a continuing teacher education programme. The aim of this programme is to give a contribution to the continuing education of teachers of English as critical professionals, aware of discursive classroom practices, able to analyze them in the light of objectives to be reached and knowledge to be constructed. The paper gives a detailed account of how teachers deal with central issues in face to face reflective sessions and online interactive discussions and shows the results of a pilot intervention aiming at helping teachers develop more reflective and critical perspectives.
Telling stories in two psychiatric interviews
Authors: Telles Ribeiro Branca , Bastos Liliana Cabral
Published: September 2007

This study investigates contextualization processes in two psychiatric interviews. Specifically, it analyses how different analytical tools — frame and narrative — work to clarify contextual embeddings and story bits. Frame analysis provides a way of looking at local and larger social contexts in talk. Specifically it provides a way of understanding “what’s going on here?” (Goffman 1974). Narrativee analysis provides a way of understanding the relation of major topics and themes in an interview situation. Most of all, the unfolding of a key story has implications for understanding who the patient is and what experience she values most in that encounter.

Frame and narrative also work to evidence what makes these interactions such a complex speech event. From a frame perspective, context may present multiple and unexpected frame embeddings. In the development of a story, key organizational components (for example, an orientation section) may display fragmented information or be absent. Frame and narrative address different questions and may clarify different social and linguistic processes at play in the interview situation.
Grammatical blending and the conceptualization of complex cases of interpretational overlap
Authors: Desagulier Guillaume
Published: September 2007

In this paper, grammatical blending is presented as an alternative to the conventional, linear overlap models of grammaticalization when it comes to conceptualizing complex cases of overlaps. The choice of the ‘emerging modal’ want to/wanna as a case study is motivated precisely by its interpretational complexity. For it appears that the grammaticalization of want to/wanna has been shaped by the compositional interaction of form and meaning. In this configuration, the linear model has to be modified for two reasons: being exclusively semantic, it does not take the form of the expression into account; being linear, it does not lend itself to a treatment of constructional compositionality. Grammatical blending, understood as the blend of constructions as defined in the Construction Grammar framework, is one way of altering the linear model so as to enable the representation of non-linear (i.e. compositional) constructional overlaps.
The ‘Literary Mind’ and changes
Authors: Achard-Bayle Guy
Published: September 2007

My purpose is to study two forms of creation of (fictitious) entities: by metamorphosis and by metaphor. Though these operations are not situated at the same ontological level (being respectively phenomena of observable — or imaginable — transformation vs discursive evolutions), the fact remains that they have the following point in common, that they modify identities, by mixing, exchanging or changing properties, and thus by their integration into a new category. My purpose will therefore be to prolong this conceptual analysis by a comparison of the textual sequences and the referential expressions where these two types of change appear; this will enable us to see that, though they often coexist, these operations have distinct semantic bases and therefore induce different interpretations — but sometimes only up to a certain point.
Indices of a ‘subjectivity-prominent’ language
Authors: Ikegami Yoshihiko
Published: September 2007

The speaker of language is primarily conceived of as locutionary subject (or ‘sujet parlant’), i.e. as a person who exchanges linguistic messages with his/her counterpart — typically in dialogic situations where the two alternate in their roles as speaker and hearer. In this setting, the speaker and the hearer are equal as speech-act participants and thus the contrast is ‘first/second person’ vs. ‘third person’ (or ‘speech-act participant’ vs. ‘non-speech-act participant’).

There is, however, another aspect of the speaker — the speaker as cognizing subject, i.e. as a person who, prior to his/her locutionary act, construes the situation to be encoded, being engaged in the monologic cognitive activity of choosing what to encode and how to encode what is to be encoded. In this capacity, the speaker is contrasted with everything he/she may want to encode and thus the contrast here is ‘first person’ vs. ‘second/third person’ — or better, ‘ego’ vs. ‘alter’.

Language may manifest features that count as indices of either of these two types of linguistic subjectivity. But individual languages may differ in the extent to which they manifest more features indicating one type of subjectivity than the other. I propose to discuss these two contrasting typological orientations by referring to my native language, Japanese, which seems to be an eminently ego-centered, or subjectivity-prominent, language.
A cognitive semantic analysis of metaphor in conceptualising Particle Physics
Authors: Cuadrado Esclapez Georgina , Berge Legrand Heliane Jill
Published: September 2007

This article presents the results of a cognitive analysis of metaphors used in conceptualisation of Particle Physics and shows how they shape our knowledge of the field. Taking as a starting point Lakoff’s Theory of Metaphor (1993), it assumes that human beings observe physical reality through their own models of experience, not as independent phenomena, many aspects of our thought and our language falling beneath cognitive awareness (Lakoff & Johnson, 1999). Hence, the language that emerges to conceptualise Physics reflects historical, emotional factors that characterise the authors of this language as witnesses of a given period of time. Examples provided contribute to demonstrate that metaphor constitutes a fundamental part of our conceptual system (Gleitman & Lieberman, 1995; Smith & Osherson, 1995), even in science.
Mapping functional-cognitive space
Authors: Gonzálvez-García Francisco , Butler Christopher S.
Published: September 2007

The aim of this paper is to describe in some detail the topography of the space occupied by functional and cognitive models. We describe the salient characteristics of functionalist, cognitivist and/or constructionist models against the general background of usage-based models, and also include in our discussion the parallel architecture framework of Jackendoff (1997, 2002a, 2002b), recently further refined as the Simpler Syntax hypothesis (Culicover & Jackendoff, 2005). A list of 36 features for the comparison of models is drawn up, and each of 11 approaches is discussed in the light of these features. Our conclusion is that although the study provides some evidence for the view that functionalist and cognitive and/or constructionist models occupy two partially distinct areas of functional/cognitive space, there is nevertheless a large group of features which are shared across all the types of model we have examined. Other groups of features allow us to distinguish between two major groups of models, one largely functionalist in its orientation, the other cognitivist and/or constructionist, the remaining models showing affinities with one or other of the two main groups, according to the feature concerned.
Introspection and cognitive linguistics
Authors: Gibbs Raymond W.
Published: September 2007

Cognitive linguists typically conduct their scholarship by relying upon their own intuitions about systematic patterns of language and what these may imply about the structure of human thought. But are linguists’ introspections reliable sources of evidence? Much work in contemporary cognitive science suggests that people’s introspections about their beliefs, feelings, and the reasons for their actions are quite inaccurate. Even trained experts often fail to recognize the real reasons for their beliefs and actions. The simple fact is that our ability to introspect upon many cognitive processes is extremely limited. This article discusses the implications of this empirical evidence for cognitive linguistic research and theory. I suggest several ways, nonetheless, by which cognitive linguists can better contribute to interdisciplinary scholarship by more systematically exploring the nature and reasons for their introspections on language and thought.
For the sake of argument
Authors: Coulson Seana , Pascual Esther
Published: September 2007

Attested instances of persuasive discourse were examined from the perspective of conceptual blending theory to reveal that serious argumentative points are often made via the construction of unrealistic blended cognitive models. The unrealistic character of these models is often related to compression, a process by which complex relationships are reconstrued with simpler, more familiar concepts. These examples show how speakers’ compressions enable them to strategically frame controversial issues, and to evoke particular sorts of affective responses consistent with their argumentative goals. Analysis points to various constraints on blending. Besides the constitutive and governing principles outlined by Fauconnier & Turner (2002), conceptual integration operations are greatly constrained by the frames and cultural models of a particular community, together with overall knowledge of the communicative event, the cognitive task, the issues dealt with, and the discursive goal. The paper focuses on pre-natal and post-mortem blends in “pro-life” rhetoric and judicial argumentation.
Early foreign language education and metalinguistic development
Authors: Charkova Krassimira Dimitrova
Published: September 2007

Studies with bilingual and multilingual subjects suggest that bilingualism and multilingualism foster the development of certain aspects of children’s metalinguistic skills. The purpose of the present study was to find out if learning foreign languages facilitates children’s metalinguistic ability to define words. It compared Bulgarian monolingual, bilingual and trilingual subjects on their word-definition performance in the L1. The relationship between L1 definition performance, L2/L3 proficiency, and L2/L3 definition performance within the bilingual and trilingual groups was also investigated.

The study found that early foreign language education has a positive effect on the quality of children’s definitions in their L1. The bilingual and trilingual children performed significantly better than the monolingual children. The results specific to the bilingual and trilingual groups showed that second/third language proficiency was a significant and powerful predictor of the performance of the bilingual and trilingual subjects on the word-definition tasks in their second/third language. L1 word-definition ability was a weaker predictor of the subjects’ performance on the word-definition task in their second or third language. However, in the case of genetically closely related languages (Bulgarian and Russian) the transfer was easier as compared to genetically more distanced languages (Bulgarian and English).