bluuebunny/crossref_metadata_2025 huggingface dataset:
Dyggve–Melchior–Clausen syndrome: Clinical, genetic, and radiological study of 15 Egyptian patients from nine unrelated families
Authors: Aglan Mona S. , Temtamy Samia A. , Fateen Ekram , Ashour Adel M. , Eldeeb Khamis , Hosny Gamal A.
Published: October 2009

Introduction

Dyggve–Melchior–Clausen (DMC) syndrome is a rare autosomal recessive type of skeletal dysplasia. It is characterized by the association of progressive spondyloepimetaphyseal dysplasia (SEMD), microcephaly, mental retardation (MR), and coarse facies. The radiographic appearance of generalized platyspondyly with double-humped end plates and the lace-like appearance of iliac crests are pathognomonic and distinctive of DMC syndrome. The disorder results from mutations in the DYM gene mapped in the 18q12-12.1 chromosomal region.

Materials and methods

In this report, we studied 15 Egyptian cases with DMC syndrome from nine unrelated families. We aimed to emphasize the characteristic clinical and radiological features in order to differentiate the condition from other SEMDs and mucopolysaccharidosis (MPS). Patients were subjected to detailed history taking, three-generation family pedigree analysis, complete physical examination, anthropometric measurements, quantitative estimation, and two-dimensional electrophoresis of glycosaminoglycans in the urine and measurement of α-l-iduronidase and galactose-6-sulfatase enzyme activities to exclude Hurler and Morquio diseases (MPS type I and MPS type IVA), respectively. Other investigations were carried out whenever indicated. All patients were the offspring of consanguineous apparently normal parents. Positive family history and similarly affected sibs were noted, confirming the autosomal recessive inheritance pattern of the syndrome. Short stature, microcephaly, variable degree of MR, and coarse facies were constant features. The frequency of characteristic orthopedic and radiological findings was reported. Orthopedic surgical intervention was carried out for two patients.

Conclusions

The study concluded that DMC syndrome may be more frequent in Egypt than previously thought, especially due to misdiagnosis. Characteristic facial dysmorphism, body habitus, and pathognomonic radiological signs suggest the diagnosis and differentiate it from other types of SEMDs and MPS for proper genetic counseling and management.
Rapid Metastasis to the Scrotum and Penis following Laparoscopic Radical Cystoprostatectomy
Authors: Vasdev Nikhil , Brown Dougal , Marsh Ralph , Armitage Trevor , Menezes Pravin
Published: October 2009

We present a case of rapid metastasis to the scrotum and penis within 2 months following a laparoscopic radical cystoprostatectomy in a 61-year-old male. The aim of this case report is to highlight the potential risk of rapid metastasis to both urologist and urological oncologist in all patients undergoing a laparoscopic radical cystoprostatectomy.
Architects of Armageddon: the Home Office Scientific Advisers' Branch and civil defence in Britain, 1945–68
Authors: SMITH MELISSA
Published: October 2009

In 1948, in response to the perceived threat of atomic war, the British government embarked on a new civil defence programme. By the mid-1950s, secret government reports were already warning that this programme would be completely inadequate to deal with a nuclear attack. The government responded to these warnings by cutting civil defence spending, while issuing apparently absurd pamphlets advising the public on how they could protect themselves from nuclear attack. Historians have thus far sought to explain this response with reference to high-level decisions taken by policymakers, and have tended to dismiss civil defence advice as mere propaganda. This paper challenges this interpretation by considering the little-known role of the Home Office Scientific Advisers' Branch, a group of experts whose scientific and technical knowledge informed both civil defence policy and advice to the public. It explores both their advisory and research work, demonstrating their role in shaping civil defence policy and showing that detailed research programmes lay behind the much-mocked government civil defence pamphlets of the 1950s and 1960s.
Dietary intake and urinary excretion of lignans in Finnish men
Authors: Nurmi Tarja , Mursu Jaakko , Peñalvo José L. , Poulsen Henrik E. , Voutilainen Sari
Published: October 2009

Intake of lignans has been assessed in different study populations, but so far none of the studies has compared the daily intake of lignans and the urinary excretion of plant and enterolignans. We assessed the intake of lariciresinol, pinoresinol, secoisolariciresinol and matairesinol in 100 Finnish men consuming their habitual omnivorous diet, and measured the 24 h urinary excretion of plant and enterolignans to compare the intake and metabolism. Dietary determinants of lignan intake and their urinary excretion were also determined. The mean intake of lignans was 1224 (sd 539) μg/d, of which lariciresinol and pinoresinol covered 78 %. Almost half (47 %) of the intake of lignans was explained by the intake of rye products, berries, coffee, tea and roots. The urinary excretion of plant lignans corresponded to 17 % and enterolignans to 92 % of the intake of lignans. The urinary excretion of plant lignans was explained 14 % by the intake of rye products and intake of coffee, and consequently 3–7 % by the intake of water-insoluble fibre. The urinary excretion of enterolactone was explained 11 % by the intake of vegetables and rye products, 14 % by the intake of water-soluble fibre and only 4 % by the intake of lariciresinol. Although the assessed intake of lignans corresponded well with the urinary excretion of lignans, the enterolactone production in the human body depended more on the dietary sources of lignans than the absolute intake of lignans.
Predicting hydraulic properties of seasonally impounded soils
Authors: PATIL N. G. , RAJPUT G. S. , NEMA R. K. , SINGH R. B.
Published: October 2009

Agricultural crop management decisions often require data on hydraulic properties of soils. Little information is available on hydraulic properties of clay soils that are impounded by rainwater (known as ‘Haveli’ lands) every year during the monsoon season in large tracts of Madhya Pradesh in India. Estimating hydraulic properties using global pedotransfer functions (PTFs) is one possible way to collect such information. Rules in the widely used global PTF Rosetta were executed to obtain estimates of two important hydraulic properties, namely soil water retention characteristics (SWRC) and saturated hydraulic conductivity (Ks). SWRC estimates obtained with maximum input (particle size distribution, bulk density, field capacity and permanent wilting point) in Rosetta were relatively closer to the laboratory-measured data as compared with the estimates obtained with lower levels of input. Root mean square error (RMSE) of estimates ranged from 0·01 to 0·05 m3/m3. Hierarchical PTFs to predictKsfrom basic soil properties were derived using statistical regression and artificial neural networks. Evaluation of these indicated that neural PTFs were acceptable and hence could be used without loss of accuracy.
Hard-to-Value Stocks, Behavioral Biases, and Informed Trading
Authors: Kumar Alok
Published: October 2009

This paper uses investor-level data to provide direct evidence for an intuitive but surprisingly untested proposition that investors make larger investment mistakes when valuation uncertainty is higher and stocks are more difficult to value. Using multiple measures of valuation uncertainty and multiple behavioral bias proxies, I show that individual investors exhibit stronger behavioral biases when stocks are harder to value and when market-level uncertainty is higher. I also find that informed trading intensity is higher among stocks where individual investors exhibit stronger behavioral biases. Collectively, these results indicate that uncertainty at both stock and market levels amplifies individual investors’ behavioral biases and that relatively better informed investors attempt to exploit those biases.
Support for the mutual maintenance of pain and post-traumatic stress disorder symptoms
Authors: Liedl A. , O'Donnell M. , Creamer M. , Silove D. , McFarlane A. , Knaevelsrud C. , Bryant R. A.
Published: October 2009

Background

Pain and post-traumatic stress disorder (PTSD) are frequently co-morbid in the aftermath of a traumatic event. Although several models attempt to explain the relationship between these two disorders, the mechanisms underlying the relationship remain unclear. The aim of this study was to investigate the relationship between each PTSD symptom cluster and pain over the course of post-traumatic adjustment.

Method

In a longitudinal study, injury patients (n=824) were assessed within 1 week post-injury, and then at 3 and 12 months. Pain was measured using a 100-mm Visual Analogue Scale (VAS). PTSD symptoms were assessed using the Clinician-Administered PTSD Scale (CAPS). Structural equation modelling (SEM) was used to identify causal relationships between pain and PTSD.

Results

In a saturated model we found that the relationship between acute pain and 12-month pain was mediated by arousal symptoms at 3 months. We also found that the relationship between baseline arousal and re-experiencing symptoms, and later 12-month arousal and re-experiencing symptoms, was mediated by 3-month pain levels. The final model showed a good fit [χ2=16.97, df=12, p>0.05, Comparative Fit Index (CFI)=0.999, root mean square error of approximation (RMSEA)=0.022].

Conclusions

These findings provide evidence of mutual maintenance between pain and PTSD.
Sociocultural theory and second language acquisition
Authors: Lantolf James P. , Beckett Tracy G.
Published: October 2009

Second language acquisition (SLA) research informed by sociocultural theory (henceforth, SCT) began in earnest with the publication of Frawley & Lantolf's (1985) article on L2 (second language) discourse (described in the timeline proper). Since then, well over 300 journal articles, book chapters and doctoral dissertations have appeared in the research literature. Although the term ‘sociocultural’ is often applied to a wide array of approaches to research that seeks to understand what it means to be a human being, in the present timeline, we restrict its interpretation to refer to the specific theory of psychological development proposed by Vygotsky (1986). Other approaches that have appropriated the term, such as those emanating from the writings of Bakhtin (1981), while compatible in many respects with Vygotskian theory, have a different focus and are not strictly speaking psychological or psycholinguistic theories. To be sure, Vygotsky rarely used the term ‘sociocultural’, preferring instead ‘cultural psychology’ or ‘cultural-historical psychology’ to refer to his theory. Wertsch (1985) is generally credited with having coined the term ‘sociocultural’ as a way of capturing the notion that human mental functioning results from participation in, and appropriation of, the forms of cultural mediation integrated into social activities.
Language in the Workplace Project and Workplace Communication for Skilled Migrants course at Victoria University of Wellington, New Zealand
Authors: de Bres Julia ,   the Language in the Workplace Team (Janet Holmes, Angela Joe, Meredith Marra, Jonathan Newton, Nicky Riddiford & Bernadette Vine)
Published: October 2009

The School of Linguistics and Applied Language Studies (LALS) at Victoria University of Wellington conducts research and teaching in Linguistics, Applied Linguistics, Writing and Deaf Studies. It incorporates a Deaf Studies Research Unit, which undertakes research on topics relating to deaf people and their language in New Zealand, and the New Zealand Dictionary Centre, set up in partnership with Oxford University Press, which provides a base for research into New Zealand lexicography and aspects of language in New Zealand. It also incorporates an English Language Institute, which specialises in teaching English language courses and teacher education programmes. A particular strength of the School's makeup is the opportunity to engage in research which benefits and is benefited by both theoretical and practical approaches to issues in linguistics and applied linguistics. This report describes one of a number of examples of the productive integration of language teaching and language research at LALS. We describe an ongoing research project that has developed organically over the past twelve years. The research involved first collecting and analysing authentic workplace interaction between native speakers, and then making use of it in explicit instruction aimed at developing socio-pragmatic proficiency in the workplace among skilled migrants with English as an Additional Language (EAL). We are now engaged in evaluating the results of the instruction, not only in the classroom, but also in workplaces where the migrants have been placed as interns.
Research in second language studies at Michigan State University
Authors: White Benjamin , Fei Fei , Russell Marthe
Published: October 2009

The Second Language Studies (SLS) Program was established in 2005 with the express purpose of providing ‘a firm foundation in the field of Second Language Acquisition and its application to current second language research and teaching’ (http://sls.msu.edu). Under the leadership of Professor Susan Gass, the program has grown to include 12 core faculty members and 27 Ph.D. students. As an interdisciplinary program, linkages across the university exist with the Department of Linguistics and Germanic, Slavic, Asian, and African Languages; the Department of French, Classics, and Italian; the Department of Spanish and Portuguese; the Arabic Language Instruction Flagship; the M.A. TESOL Program; the Center for Language Education and Research; the English Language Center; the Center for the Support of Language Teaching; the Department of Psychology; and the College of Education.
Influence of soil, topography and substrates on differences in wood decomposition between one-hectare plots in lowland tropical moist forest in Central Amazonia
Authors: de Toledo José Julio , Magnusson William Ernest , de Castilho Carolina Volkmer
Published: October 2009

Understanding how wood decomposition varies spatially at the mesoscale (between 1-ha plots) may improve carbon flux estimates in Amazonian forests. An experiment was carried out to test the influence of soil, slope, above-ground tree live biomass (biomass), fine-litter mass and characteristics of neighbouring trees on the variation of wood decomposition between 1-ha plots in four species of tropical trees that vary in wood density (Manilkara huberi – 0.86 g cm−3, Couratari guianensis – 0.54 g cm−3, Hura crepitans – 0.32 g cm−3 and Parkia pendula – 0.29 g cm−3). A wood sample from each species (30 × 5 × 2.5 cm) was placed in each of 71 plots within 64 km2 of terra firme tropical moist forest in Reserva Florestal Adolpho Ducke. One year later, samples were collected and weighed. The effects of specificity of decomposers was measured by the association of decomposition with the wood density and with the taxonomic group of the nearest tree with dbh ≥30 cm. Wood decomposition was independent of soil (texture and nutrients), slope, biomass and fine-litter mass at the mesoscale, except for C. guianensis, which showed greater decomposition in locations with greater biomass. Decomposition was also independent of wood density and taxonomic group of nearby large trees. In general, none of the variables was useful as a predictor of wood decomposition at the scale larger than 1 ha. Thus, the use of models that include soil and topography to improve estimates of carbon flux are limited because wood decomposition does not follow similar mesoscale patterns to that of biomass and fine-litter decomposition. Also, the results indicate that wood decomposition is more likely to be associated with generalist decomposers than with specialists associated with neighbouring trees.
Territoriality in females of the slender opossum (Marmosops paulensis) in the Atlantic forest of Brazil
Authors: Leiner Natália Oliveira , Silva Wesley Rodrigues
Published: October 2009

Spatial organization within animal populations is often thought to reflect the outcome of strategies implemented by each individual to enhance its reproductive success and survival (Clutton-Brock 1989). Thus, while females usually focus on the acquisition of food and breeding sites, male dispersion is more often determined by the distribution and availability of females (Clutton-Brock 1989). Due to these factors, intraspecific competition for space could lead to the adoption of a territorial strategy, whenever the benefits of territorial defence are higher than the costs (Brown & Orians 1970). Among small mammals, two main hypotheses have been proposed to explain the occurrence of territoriality in females. Ostfeld (1990) proposed that females should defend food resources, so the distribution and availability of food items should determine the cost–benefit relationship of adopting a territorial strategy. However, Wolff (1993) developed a hypothesis, based on small rodents, that females should defend nest sites in order to avoid infanticide, the so-called pup-defence hypothesis.
Volume measurements for quicker determination of forest litter standing crop
Authors: Parsons Scott A. , Shoo Luke P. , Williams Stephen E.
Published: October 2009

Litter standing crop (LSC) is the quantity of plant detritus on the floor in forested environments. Knowledge of LSC is important in understanding many ecological phenomena. These include studies of litterfall, decomposition/litter turnover rates and nutrient cycling (Anderson et al. 1983, Dent et al. 2006), general plant performance (Benítez-Malvido & Kossmann-Ferraz 1999), other ecosystem processes such as the effects of fire (Odiwe & Muoghalu 2003) and fauna (Frith & Frith 1990, Giaretta et al. 1999, Levings & Windsor 1985). The determination of accurate annual average LSC data, may require monitoring over long periods due to seasonality and sometimes sporadic nature of litterfall and decomposition rates (Clark et al. 2001). Furthermore, the effects of topography and water movement create the need for both representative site selection and sufficient spatial coverage.
Early effect of elevated nitrogen input on above-ground net primary production of a lower montane rain forest, Panama
Authors: Adamek Markus , Corre Marife D. , Hölscher Dirk
Published: October 2009

To evaluate N limitation on above-ground net primary production in a tropical lower montane rain forest, an N fertilization experiment was conducted for 2 y. The study site is located at 1200–1300 m asl in the Fortuna forest reserve in western Panama and has a mature, mixed-species stand growing on an Andisol soil. Control and N-fertilized (125 kg urea-N ha−1 y−1) treatments were represented by four replicate plots (each 40 × 40 m, separated by at least 40 m). Stem diameter growth was analysed by diameter at breast height classes and also for the three most abundant species. The three species did not respond to N addition. The response of stem growth and above-ground woody biomass production to N fertilization varied among dbh classes. Stem growth of trees of 10–30 cm dbh increased only in the first year of N addition while trees of 30–50 cm dbh responded in the second year of N addition, which may be due to differences in light conditions between years. Trees >50 cm dbh did not respond during 2 years of N addition. As a result, the overall stem growth and above-ground woody biomass production were not affected by N fertilization. Annual total fine litterfall increased in the first year of N fertilization, while annual leaf litterfall increased in both years of N addition. Above-ground net primary production, of which total fine litterfall constituted 68%, also increased only in the first year of N addition. The magnitude and timing of response of stem diameter growth and litterfall suggest that these aspects of above-ground productivity are not uniformly limited by N availability.
AN EXTREMELY-LOW-INTEREST-RATE POLICY AND THE SHAPE OF THE JAPANESE MONEY DEMAND FUNCTION
Authors: Nakashima Kiyotaka
Published: October 2009

This paper explores the shape of the Japanese money demand function in relation to the historical path of the Bank of Japan's policy rate by employing Saikkonen and Choi's [Econometric Theory 20, 301–340 (2004)] cointegrating smooth transition model. The nonlinear model provides a unified econometric framework, not only for pursuing the time profile of interest elasticity, but also to test the linearity of the Japanese money demand function. The test results for the linearity of the Japanese money demand function provide evidence of nonlinearity with a semilog model and linearity with a double-log model. Using a nonlinear semilog model, the analysis also finds that Japanese money demand comprises three regimes and that the interest semielasticity began to increase in the early 1990s when the Bank of Japan set the policy rate below 3%.
BUSINESS CYCLE EVIDENCE ON FIRM ENTRY
Authors: Lewis Vivien
Published: October 2009

Business cycle models with sticky prices and endogenous firm entry make novel predictions on the transmission of shocks through the extensive margin of investment. I test some of these predictions using a VAR with model-based sign restrictions. I find a positive and significant response of firm entry to expansionary shocks to productivity, aggregate spending, monetary policy, and entry costs. The estimated response to a monetary expansion does not support the monetary policy transmission mechanism proposed by the model. Insofar as firm startups require labor services, wage stickiness is needed to make thesignsof the model responses consistent with the estimated ones. Theshapesof the empirical responses suggest that congestion effects in entry make it harder for new firms to survive when the number of startups rises.
The crosstalk of hyaluronan-based extracellular matrix and synapses
Authors: Frischknecht Renato , Seidenbecher Constanze I.
Published: October 2009

Many neurons and their synapses are enwrapped in a brain-specific form of the extracellular matrix (ECM), the so-called perineuronal net (PNN). It forms late in the postnatal development around the time when synaptic contacts are stabilized. It is made of glycoproteins and proteoglycans of glial as well as neuronal origin. The major organizing polysaccharide of brain extracellular space is the polymeric carbohydrate hyaluronic acid (HA). It forms the backbone of a meshwork consisting of CNS proteoglycans such as the lectican family of chondroitin sulphate proteoglycans (CSPG). This family comprises four abundant components of brain ECM: aggrecan and versican as broadly expressed CSPGs and neurocan and brevican as nervous-system-specific family members. In this review, we intend to focus on the specific role of the HA-based ECM in synapse development and function.
Low‐temperature thermochronology and thermokinematic modeling of deformation, exhumation, and development of topography in the central Southern Alps, New Zealand
Authors: Herman Frédéric , Cox Simon C. , Kamp Peter J. J.
Published: October 2009

Apatite and zircon (U‐Th)/He and fission track ages were obtained from ridge transects across the central Southern Alps, New Zealand. Interpretation of local profiles is difficult because relationships between ages and topography or local faults are complex and the data contain large uncertainties, with poor reproducibility between sample duplicates. Data do form regional patterns, however, consistent with theoretical systematics and corroborating previous observations: young Neogene ages occur immediately southeast of the Alpine Fault (the main plate boundary structure on which rocks are exhumed); partially reset ages occur in the central Southern Alps; and older Mesozoic ages occur further toward the southeast. Zircon apparent ages are older than apatite apparent ages for the equivalent method. Three‐dimensional thermokinematic modeling of plate convergence incorporates advection of the upper Pacific plate along a low‐angle detachment then up an Alpine Fault ramp, adopting a generally accepted tectonic scenario for the Southern Alps. The modeling incorporates heat flow, evolving topography, and the detailed kinetics of different thermochronometric systems and explains both complex local variations and regional patterns. Inclusion of the effects of radiation damage on He diffusion in detrital apatite is shown to have dramatic effects on results. Geometric and velocity parameters are tuned to fit model ages to observed data. Best fit is achieved at 9 mm a−1 plate convergence, with Pacific plate delamination on a gentle 10°SE dipping detachment and more rapid uplift on a 45–60° dipping Alpine Fault ramp from 15 km depth. Thermokinematic modeling suggests dip‐slip motion on reverse faults within the Southern Alps should be highest ∼22 km from the Alpine Fault and much lower toward the southeast.
Estimating allowable carbon emission for CO2 concentration stabilization using a GCM‐based Earth system model
Authors: Miyama Toru , Kawamiya Michio
Published: October 2009

For atmospheric CO2 concentration stabilization, we projected allowable carbon emission with an Earth system model based on a general circulation model. Our calculations on centennial timescale in various scenarios reveal how saturation with respect to CO2 and climate‐carbon cycle feedback reduce natural carbon uptake, and hence allowable emission. In 450 ppm stabilization scenario, for example, climate‐carbon cycle feedback reduces the accumulative allowable carbon emission until year 2300 from 1248 to 980 PgC. The Emission at the year 2050 is about the half of the year 2000 level for the SP450 scenario. Terrestrial carbon cycle is especially susceptible to climate‐carbon cycle feedback, and is a significant source of projection uncertainty. Our model responds nonlinearly to CO2 and climate, suggesting process‐based models are indispensable tool for future climate‐carbon cycle projections.
Energetic electron precipitation from the outer radiation belt during geomagnetic storms
Authors: Horne Richard B. , Lam Mai Mai , Green Janet C.
Published: October 2009

Relativistic electron precipitation changes the chemistry of the upper atmosphere and depletes ozone, but the spatial and temporal distributions are poorly known. Here we survey more than 9 years of data from low altitude satellites for different phases of geomagnetic storms. We find that for the outer radiation belt, electron precipitation >300 keV peaks during the main phase of storms whereas that >1 MeV peaks during the recovery phase. Precipitation >300 keV can occur at all geographic longitudes in both hemispheres whereas that >1 MeV occurs mainly poleward of the South Atlantic anomaly (SAA) region. The data suggest that wave‐particle interactions are strong enough to precipitate >300 keV electrons into the bounce loss cone, but precipitate >1 MeV electrons into the drift loss cone. We find that whistler mode chorus waves alone cannot account for the higher MeV precipitation flux during the recovery phase. We suggest that whistler mode chorus waves accelerate electrons up to MeV energies during the recovery phase which are then precipitated by EMIC waves. The effects on atmospheric chemistry due to MeV electron precipitation are more likely to occur in the southern hemisphere poleward of the SAA region with a delay of 1–2 days or more from the peak of the storm.
Seasonal and latitudinal differences of the saturation effect between ionospheric NmF2 and solar activity indices
Authors: Ma Ruiping , Xu Jiyao , Wang Wenbin , Yuan Wei
Published: October 2009

The seasonal and latitudinal differences of the correlations between daytime ionospheric F2 peak electron density (NmF2) and solar activity indices in the east Asian/Australian sector have been analyzed using data from 15 ionosonde stations at different geomagnetic latitudes during 1969∼1990. It is found that the characteristics of the correlations between NmF2 and solar activity indices have significant seasonal and latitudinal variations and hemispheric asymmetry. At middle and high latitudes, there is a clear saturation trend in NmF2 as solar activity increases in summer. However, there is no apparent saturation trend in winter, rather a tendency of nonlinear increase of NmF2 with solar activity. This nonlinear increasing effect is more pronounced in the Northern Hemisphere. In the equatorial anomaly region, the saturation effect is stronger, and the equinox has the strongest saturation effect. All seasons considered, the equatorial anomaly region has the strongest saturation effect, followed by the magnetic equatorial region. The saturation effect becomes relatively weak at middle latitudes. At higher latitudes and in the Northern Hemisphere, there is even a trend of nonlinear increase of NmF2 with solar activity. Our results indicate that thermospheric global circulation is probably an important factor that introduces seasonal, latitudinal, and north–south differences in the correlations between NmF2 and solar activity indices.
Longitudinal variability in intraseasonal oscillation in the tropical mesosphere and lower thermosphere region
Authors: Rao R. Kondala , Gurubaran S. , Sathishkumar S. , Sridharan S. , Nakamura T. , Tsuda T. , Takahashi H. , Batista P. P. , Clemesha B. R. , Buriti R. A. , Pancheva D. V. , Mitchell N. J.
Published: October 2009

Simultaneous observations of mean zonal wind at 88 km obtained by the meteor radars at Cariri (7.4°S, 36.5°W) and Ascension Island (7.9°S, 14.4°W) and two medium‐frequency radars at Tirunelveli (8.7°N, 77.8°E) and Pamuengpeuk (7.7°S, 107.7°E) have been used to investigate the influence of the intraseasonal variations in the lower tropospheric convective activity associated with the Madden‐Julian oscillation on the longitudinal behavior of intraseasonal oscillations (ISO) of the zonal winds in the equatorial mesosphere and lower thermosphere (MLT). The ISO activity in the lower tropospheric convective activity is examined by employing outgoing long‐wave radiation (OLR) as a proxy for deep convective activity occurring in the tropical lower atmosphere. The longitudinal and temporal variabilities of the ISO amplitudes in MLT zonal winds are explained in terms of the intraseasonal variabilities in the convective activity. We have also employed daily zonal wind data provided by the United Kingdom Meteorological Office (MetO) to examine the ISO activity in zonal winds at 25 pressure levels from the surface to 0.1 hPa (60 km height) over the respective radar locations.
Annual cycle of horizontal in‐mixing into the lower tropical stratosphere
Authors: Konopka Paul , Grooß Jens‐Uwe , Plöger Felix , Müller Rolf
Published: October 2009

Based on the HALOE and SHADOZ observations of ozone (O3) and on a simple conceptual model of transport and photochemistry, the seasonality of O3 within the stratospheric part of the tropical tropopause layer (TTL) extending between 360 and 420 K potential temperature is discussed. We show that the seasonality of O3 diagnosed on pressure (p) surfaces has a significantly larger annual cycle compared with the same kind of analysis on surfaces with constant potential temperature (θ), in particular around p = 80 hPa, where the strongest annual variation in tropical temperature occurs. Thus by using θ instead of p as the vertical coordinate, the (seasonal) adiabatic variability is removed, and consequently, a much smaller seasonal cycle of O3 remains, which can be understood as a consequence of chemistry, cross‐isentropic transport (upwelling), and horizontal, i.e., quasi‐isentropic, transport (in‐mixing). Furthermore, we show that the observed, θ‐related seasonality of O3, with highest values during boreal summer, cannot be understood only by photolytical O3 production in slowly rising air masses, which are well isolated from the extratropics. By using the SHADOZ climatology at θ = 360 K and quantifying the photochemical production of O3 in ascending air above θ = 360 K, we determine the residual variability between the observations (SHADOZ, HALOE) and the calculated O3 values and, consequently, interpret this residuum as horizontal in‐mixing from the extratropical stratosphere. We find that between 380 and 420 K, in‐mixing contributes to about 40% of the observed O3 mixing ratios during boreal summer.
Can one invasion lead to another? Niche space and the future of Southwestern U.S. riparian zones
Authors: Reynolds Lindsay , Cooper David
Published: October 2009

Background/Question/Methods:

Invasive species are increasingly problematic world-wide. Scientists working to understand why invasive species are successful must first understand the processes of invasion. Invasion facilitation and empty niche exploitation are key processes that have not been well-studied in species rich ecosystems such as riparian areas. In the southwestern United States (U.S.) two prominent invaders of riparian habitats are the exotic woody plant species tamarisk (Tamarix ramosissima, T. chinensis, and their hybrids) and Russian olive (Eleagnus angustifolia). These plants were introduced by humans throughout the southwest around 1900. Both tamarisk and Russian olive have invaded the ephemeral stream system in Canyon de Chelly National Monument, Arizona. We worked in sites within Canyon de Chelly and throughout the region to address the following questions: (1) does Russian olive have a broader niche than cottonwood and tamarisk? And (2) can cottonwood and tamarisk facilitate Russian olive invasion by providing shaded habitat? We analyzed riparian tree seedling requirements in a controlled experiment, and performed empirical field studies at sites in Canyon de Chelly, and throughout the Colorado Plateau region.

Results/Conclusions:

Our controlled experiment and field surveys indicate that Russian olive can establish and survive under shadier and drier conditions than tamarisk and native cottonwood. Russian olive survival was significantly higher in dense shade, and low soil moisture treatments than tamarisk and cottonwood. In the field, we found Russian olive establishing on a local and regional scale, up to 8 meters above the stream channel, in sites where flooding cannot occur. It established under dense canopies of tamarisk, cottonwood and Russian olive. Tamarisk and native riparian plants species seedlings cannot establish in these dry, shady habitats. Russian olive is limited only by seed dispersal in southwestern riparian ecosystems. Although Russian olive did not show a preference for shaded habitat and is therefore not being facilitated by cottonwood and tamarisk, our results demonstrate it has a much broader niche than cottonwood and tamarisk. Some researchers suggest that native cottonwood trees are undergoing population declines and invasive tamarisk trees have invaded all possible habitats in the southwestern US. The potential for continued Russian olive invasions in southwestern riparian ecosystems is tremendous. Russian olive will likely increase in abundance while tamarisk and cottonwood decrease along rivers in the southwestern US. Generalist exotic species that have broader niches than native species have the potential to exclude native species and create novel ecosystems where community composition is dominated by exotic species.
PPARγ Expression After a High‐fat Meal Is Associated With Plasma Superoxide Dismutase Activity in Morbidly Obese Persons
Authors: Garcia‐Fuentes Eduardo , Murri Mora , Garrido‐Sanchez Lourdes , Garcia‐Serrano Sara , García‐Almeida Jose M. , Moreno‐Santos Inmaculada , Tinahones Francisco J. , Macias‐Gonzalez Manuel
Published: October 2009

Peroxisome proliferator‐activated receptor‐γ (PPARγ) may play a protective role in the regulation of vascular function, partly mediated by its effects on superoxide dismutase (SOD). The aim of this study was to determine the association between PPARγ expression in peripheral blood mononuclear cells (PBMCs) and SOD activity in morbidly obese persons with varying degrees of insulin resistance (IR). We studied in 10 morbidly obese persons (five with no IR and five with high IR) the effect of a high‐fat meal on the plasma activity of various antioxidant enzymes and the mRNA expression of PPARγ in PBMC. The high‐fat meal resulted in a significant decrease in plasma SOD activity, glutathione reductase (GSH‐Rd) activity, and mRNA expression of PPARγ only in the group of morbidly obese persons with high IR. PPARγ expression after the high‐fat meal correlated with the IR levels (r = −0.803, P = 0.009) and the plasma SOD activity (r = 0.903, P = 0.001). Likewise, the reduction in PPARγ expression correlated with the increase in free fatty acids (FFA) (r = 0.733, P = 0.016). In conclusion, the decreased expression of PPARγ in PBMC in morbidly obese persons after a high‐fat meal was associated with the state of IR, the plasma SOD activity, and the changes in the concentration of FFA.
Exercise Training Prevents Regain of Visceral Fat for 1 Year Following Weight Loss
Authors: Hunter Gary R. , Brock David W. , Byrne Nuala M. , Chandler‐Laney Paula C. , Del Corral Pedro , Gower Barbara A.
Published: October 2009

The purpose of this study was to determine what effect aerobic and resistance exercise training has on gain of visceral fat during the year following weight loss. After being randomly assigned to aerobic training, resistance training, or no exercise training, 45 European‐American (EA) and 52 African‐American (AA) women lost 12.3 ± 2.5 kg on a 800 kcal/day diet. Computed tomography was used to measure abdominal subcutaneous and visceral adipose tissue, whereas total fat and regional fat (leg, arm, and trunk) were measured by dual energy X‐ray absorptiometry after weight loss and 1 year following the weight loss. Because not all the subjects adhered to the 2 time/week 40 min/day exercise training during the 1‐year follow‐up, subjects were divided into five groups for analysis: aerobic adherers, aerobic nonadherers, resistance adherers, resistance nonadherers, and no exercise. No significant differences were observed between the aerobic training and resistance training adherers for any variable. However, the aerobic (3.1 kg) and resistance (3.9 kg) exercise adherers gained less weight than any of the other three groups (all >6.2 kg). In addition, the two exercise adherence groups did not significantly increase visceral fat (<0.8%) as compared with the 38% increase for the two nonadhering exercise groups and the 25% for the nonexercise group. In conclusion, as little as 80 min/week aerobic or resistance training had modest positive effects on preventing weight regain following a diet‐induced weight loss. More importantly, both aerobic and resistance training prevented regain of potentially harmful visceral fat.
BMI and Neuronal Integrity in Healthy, Cognitively Normal Elderly: A Proton Magnetic Resonance Spectroscopy Study
Authors: Gazdzinski Stefan , Millin Rachel , Kaiser Lana G. , Durazzo Timothy C. , Mueller Susanne G. , Weiner Michael W. , Meyerhoff Dieter J.
Published: October 2009

Recent studies associated excess body weight with brain structural alterations, poorer cognitive function, and lower prefrontal glucose metabolism. We found that higher BMI was related to lower concentrations of N‐acetyl‐aspartate (NAA, a marker of neuronal integrity) in a healthy middle‐aged cohort, especially in frontal lobe. Here, we evaluated whether NAA was also associated with BMI in a healthy elderly cohort. We used 4 Tesla proton magnetic resonance spectroscopy (1H MRS) data from 23 healthy, cognitively normal elderly participants (69.4 ± 6.9 years; 12 females) and measured concentrations of NAA, glutamate (Glu, involved in cellular metabolism), choline‐containing compounds (Cho, involved in membrane metabolism), and creatine (Cr, involved in high‐energy metabolism) in anterior (ACC) and posterior cingulate cortices (PCC). After adjustment for age, greater BMI was related to lower NAA/Cr and NAA/Cho ratios (β < −0.56, P < 0.008) and lower Glu/Cr and Glu/Cho ratios (β < −0.46, P < 0.02) in ACC. These associations were not significant in PCC (β > −0.36, P > 0.09). The existence of an association between NAA and BMI in ACC but not in PCC is consistent with our previous study in healthy middle‐aged individuals and with reports of lower frontal glucose metabolism in young healthy individuals with elevated BMI. Taken together, these results provide evidence that elevated BMI is associated with neuronal abnormalities mostly in frontal brain regions that subserve higher cognitive functions and impulse control. Future studies need to evaluate whether these metabolite abnormalities are involved in the development and maintenance of weight problems.
A putrescine–anthracene conjugate: a paradigm for selective drug delivery
Authors: Palmer Andrew J. , Ghani Radiah A. , Kaur Navneet , Phanstiel Otto , Wallace Heather M.
Published: October 2009

Increased polyamine concentrations play an important role in the development of cancer at all stages, from initiation through to maintenance of the transformed phenotype. One way cancer cells accumulate increased concentrations of polyamines is by increased uptake of preformed polyamines via their PTS (polyamine transport system). The PTS is promiscuous and will transport a range of polyamine-based molecules. Therefore it may be that cytotoxic drugs could be attached to polyamine vectors and targeted selectively to cancer cells by utilizing the PTS. The aim of the present study was to investigate the potential of Ant 4, a putrescine–anthracene conjugate, to target cytotoxic agents to human cancer cells as a paradigm for a novel method of selective drug delivery. Ant 4 induced cytotoxicity after only 24 h exposure. Apoptosis was the predominant type of cell death, with mechanistic studies revealing that oxidative stress and DNA damage may have a part to play. For the first time, uptake of Ant 4 via the PTS was demonstrated both directly and indirectly in human cell lines. In addition, Ant 4 significantly reduced putrescine uptake, demonstrating that this conjugate not only used the PTS, but also could successfully compete with its native polyamine for uptake. However, the most interesting finding was the intracellular depletion of the polyamine pools, providing an additional mode of toxicity for Ant 4 and the possibility that this molecule may act as a ‘double-edged sword’: preventing cell growth by delivery of the toxic moiety and by depletion of intracellular polyamine content.
A di-arginine motif contributes to the ER localization of the type I transmembrane ER oxidoreductase TMX4
Authors: Roth Doris , Lynes Emily , Riemer Jan , Hansen Henning G. , Althaus Nils , Simmen Thomas , Ellgaard Lars
Published: October 2009

The thiol-disulfide oxidoreductases of the PDI (protein disulfide isomerase) family assist in disulfide-bond formation in the ER (endoplasmic reticulum). In the present study, we have shown that the previously uncharacterized PDI family member TMX4 (thioredoxin-like transmembrane 4) is an N-glycosylated type I membrane protein that localizes to the ER. We also demonstrate that TMX4 contains a single ER-luminal thioredoxin-like domain, which, in contrast with similar domains in other PDIs, is mainly oxidized in living cells. The TMX4 transcript displays a wide tissue distribution, and is strongly expressed in melanoma cells. Unlike many type I membrane proteins, TMX4 lacks a typical C-terminal di-lysine retrieval signal. Instead, the cytoplasmic tail has a conserved di-arginine motif of the RXR type. We show that mutation of the RQR sequence in TMX4 to KQK interferes with ER localization of the protein. Moreover, whereas the cytoplasmic region of TMX4 confers ER localization to a reporter protein, the KQK mutant of the same protein redistributes to the cell surface. Overall, features not commonly found in other PDIs characterize TMX4 and suggest unique functional properties of the protein.
C/EBP transcription factors regulate SREBP1c gene expression during adipogenesis
Authors: Payne Victoria A. , Au Wo-Shing , Lowe Christopher E. , Rahman Shaikh M. , Friedman Jacob E. , O'Rahilly Stephen , Rochford Justin J.
Published: October 2009

The transcription factor SREBP1c (sterol-regulatory-element-binding protein 1c) is highly expressed in adipose tissue and plays a central role in several aspects of adipocyte development including the induction of PPARγ (peroxisome-proliferator-activated receptor γ), the generation of an endogenous PPARγ ligand and the expression of several genes critical for lipid biosynthesis. Despite its significance, the regulation of SREBP1c expression during adipogenesis is not well characterized. We have noted that in several models of adipogenesis, SREBP1c expression closely mimics that of known C/EBPβ (CCAAT/enhancer-binding protein β) targets. Inhibition of C/EBP activity during adipogenesis by expressing either the dominant-negative C/EBPβ LIP (liver-enriched inhibitory protein) isoform, the co-repressor ETO (eight-twenty one/MTG8) or using siRNAs (small interfering RNAs) targeting either C/EBPβ or C/EBPδ significantly impaired early SREBP1c induction. Furthermore, ChIP (chromatin immunoprecipitation) assays identified specific sequences in the SREBP1c promoter to which C/EBPβ and C/EBPδ bind in intact cells, demonstrating that these factors may directly regulate SREBP1c expression. Using cells in which C/EBPα expression is inhibited using shRNA (short hairpin RNA) and ChIP assays we show that C/EBPα replaces C/EBPβ and C/EBPδ as a regulator of SREBP1c expression in maturing adipocytes. These results provide novel insight into the induction of SREBP1c expression during adipogenesis. Moreover, the findings of the present study identify an important additional mechanism via which the C/EBP transcription factors may control a network of gene expression regulating adipogenesis, lipogenesis and insulin sensitivity.
Programmed cell death of tobacco BY‐2 cells induced by still culture conditions is affected by the age of the culture under agitation
Authors: Hiraga Asahi , Kaneta Tsuyoshi , Sato Yasushi , Sato Seiichi
Published: October 2009

Evans Blue staining indicated that actively growing tobacco BY‐2 cells in the exponential phase died more rapidly than quiescent cells in the stationary phase when the cells cultured under agitation were placed under still conditions. Fifty percent cell death was induced at about 18, 26, 80 and 140 h for early, mid, late exponential‐ and stationary‐phase cells, respectively. Actively growing cells became TUNEL (transferase‐mediated dUTP nick end labelling)‐positive more rapidly than quiescent cells, suggesting that the cell death evaluated by Evans Blue is accompanied by DNA cleavages. Electrophoresis of genomic DNA showed a typical ‘DNA laddering' pattern formed by multiples of about 200 bp internucleosomal units. Chromatin condensation was first detected at least within 24 h by light microscopy, and then cell shrinkage followed. These findings suggest that the death of BY‐2 cells induced by still conditions is PCD (programmed cell death).
Dynamic position and force measurement for multiple optically trapped particles using a high-speed active pixel sensor
Authors: Towrie M. , Botchway S. W. , Clark A. , Freeman E. , Halsall R. , Parker A. W. , Prydderch M. , Turchetta R. , Ward A. D. , Pollard M. R.
Published: October 2009

A high frame rate active pixel sensor designed to track the position of up to six optically trapped objects simultaneously within the field of view of a microscope is described. The sensor comprises 520×520 pixels from which a flexible arrangement of six independent regions of interest is accessed at a rate of up to 20 kHz, providing the capability to measure motion in multiple micron scale objects to nanometer accuracy. The combined control of both the sensor and optical traps is performed using unique, dedicated electronics (a field programmable gate array). The ability of the sensor to measure the dynamic position and the forces between six optically trapped spheres, down to femtonewton level, is demonstrated paving the way for application in the physical and life sciences.