bluuebunny/crossref_metadata_2025 huggingface dataset:
Dietary supplementation oftrans-11-vaccenic acid reduces adipocyte size but neither aggravates nor attenuates obesity-mediated metabolic abnormalities infa/faZucker rats
Authors: Mohankumar Suresh K. , Hanke Danielle , Siemens Linda , Cattini Alexander , Enns Jennifer , Shen Jianheng , Reaney Martin , Zahradka Peter , Taylor Carla G.
Published: August 2012

Conjugated linoleic acid (CLA) present in dairy and ruminant fat has beneficial effects on metabolic syndrome characteristics in humans and some rodent models. Production practices to increase the milk content of CLA are also substantially elevatingtrans-11-vaccenic acid (VA). Questions are being raised whether VA has the same beneficial actions as CLA or has adverse biological effects similar to industrially producedtrans-fatty acids. The present study examined the effects of dietary supplementation of either 0 or 1·5 % (w/w) VA for 8 weeks on lipidaemia, glycaemia, blood pressure, hepatic steatosis, adipocyte size and molecular markers of inflammation and insulin signalling infa/faZucker rats. Dietary supplementation of VA did not alter feed intake, weight gain, blood pressure or organ:body weight (BW) ratios, except the epididymal fat:BW ratio which was lower in the VA group compared with the control group. The total liver lipid concentration as an indicator of hepatic steatosis was not different between the groups. Likewise, there were no changes in fasting lipidaemia, glycaemia or oral glucose tolerance. Although there were no physiological differences observed between the groups, animals supplemented with VA had smaller adipocytes (approximately 7 % smaller than the controls). The VA group also had higher adipophilin and IL-10 protein levels in epididymal adipose tissue (1·7- and 1·4-fold higher than the controls, respectively); however, there were no changes observed in critical nodes of insulin signalling. The present study provides evidence that supplementation with VA, a naturally producedtrans-fat, has some positive effects on adipose tissue and did not exacerbate obesity-mediated metabolic abnormalities.
Climate change impacts on winter wheat yield change – which climatic parameters are crucial in Pannonian lowland?
Authors: LALIC B. , EITZINGER J. , MIHAILOVIC D. T. , THALER S. , JANCIC M.
Published: August 2012

One of the main problems in estimating the effects of climate change on crops is the identification of those factors limiting crop growth in a selected environment. Previous studies have indicated that considering simple trends of either precipitation or temperature for the coming decades is insufficient for estimating the climate impact on yield in the future. One reason for this insufficiency is that changes in weather extremes or seasonal weather patterns may have marked impacts.

The present study focuses on identifying agroclimatic parameters that can identify the effects of climate change and variability on winter wheat yield change in the Pannonian lowland. The impacts of soil type under past and future climates as well as the effect of different CO2 concentrations on yield formation are also considered. The Vojvodina region was chosen for this case study because it is a representative part of the Pannonian lowland.

Projections of the future climate were taken from the HadCM3, ECHAM5 and NCAR-PCM climate models with the SRES-A2 scenario for greenhouse gas (GHG) emissions for the 2040 and 2080 integration periods. To calibrate and validate the Met&Roll weather generator, four-variable weather data series (for six main climatic stations in the Vojvodina region) were analysed. The grain yield of winter wheat was calculated using the SIRIUS wheat model for three different CO2 concentrations (330, 550 and 1050 ppm) dependent on the integration period. To estimate the effects of climatic parameters on crop yield, the correlation coefficient between crop yield and agroclimatic indices was calculated using the AGRICLIM software. The present study shows that for all soil types, the following indices are the most important for winter wheat yields in this region: (i) the number of days with water and temperature stress, (ii) the accumulated precipitation, (iii) the actual evapotranspiration (ETa) and (iv) the water deficit during the growing season. The high positive correlations between yield and the ETa, accumulated precipitation and the ratio between the ETa and reference evapotranspiration (ETr) for the April–June period indicate that water is and will remain a major limiting factor for growing winter wheat in this region. Indices referring to negative impact on yield are (i) the number of days with a water deficit for the April–June period and (ii) the number of days with maximum temperature above 25 °C (summer days) and the number of days with maximum temperature above 30 °C (tropical days) in May and June. These indices can be seen as indicators of extreme weather events such as drought and heat waves.
The performance of the EU-Rotate_N model in predicting the growth and nitrogen uptake of rotations of field vegetable crops in a Mediterranean environment
Authors: NENDEL C. , VENEZIA A. , PIRO F. , REN T. , LILLYWHITE R. D. , RAHN C. R.
Published: August 2012

The EU-Rotate_N model was developed as a tool to estimate the growth and nitrogen (N) uptake of vegetable crop rotations across a wide range of European climatic conditions and to assess the economic and environmental consequences of alternative management strategies. The model has been evaluated under field conditions in Germany and Norway and under greenhouse conditions in China. The present work evaluated the model using Italian data to evaluate its performance in a warm and dry environment. Data were collected from four 2-year field rotations, which included lettuce (Lactuca sativa L.), fennel (Foeniculum vulgare Mill.), spinach (Spinacia oleracea L.), broccoli (Brassica oleracea L. var. italica Plenck) and white cabbage (B. oleracea convar. capitata var. alba L.); each rotation used three different rates of N fertilizer (average recommended N1, assumed farmer's practice N2=N1+0·3×N1 and a zero control N0). Although the model was not calibrated prior to running the simulations, results for above-ground dry matter biomass, crop residue biomass, crop N concentration and crop N uptake were promising. However, soil mineral N predictions to 0·6 m depth were poor. The main problem with the prediction of the test variables was the poor ability to capture N mineralization in some autumn periods and an inappropriate parameterization of fennel. In conclusion, the model performed well, giving results comparable with other bio-physical process simulation models, but for more complex crop rotations. The model has the potential for application in Mediterranean environments for field vegetable production.
New molecular data on Pyrenulaceae from Sri Lanka reveal two well-supported groups within this family
Authors: WEERAKOON Gothamie , APTROOT André , LUMBSCH H. Thorsten , WOLSELEY Patricia A. , WIJEYARATNE S. Chandrani , GUEIDAN Cécile
Published: August 2012

Pyrenulaceae is one of the dominant lichen families in the tropics, especially in lowland evergreen forests. Although very species-rich, phylogenetic relationships within Pyrenulaceae have not been extensively studied using molecular data, and its morphology-based generic delimitation remains untested. A recent lichenological survey carried out in the Knuckles Mountain Range in Sri Lanka allowed the first author to collect fresh specimens of different species of Pyrenula, and to investigate the phylogenetic relationships within the family Pyrenulaceae using a multigene analysis (ITS, nuLSU and mtSSU) and a preliminary dataset of 21 taxa. This data shows that the family Pyrenulaceae can be divided into two well-supported groups and suggests that the genus Pyrenula is not monophyletic. Characters usually used for generic classification in this family (ascospore colour and septation, structure of the ascospore locules, secondary chemistry, hamathecium structure, ostiole position) do not correlate with these two groups. However, the presence of pseudocyphellae is restricted to species of Pyrenula from one group.
Translocation of solutes and proteins across the glycosomal membrane of trypanosomes; possibilities and limitations for targeting with trypanocidal drugs
Authors: GUALDRÓN-LÓPEZ MELISA , BRENNAND ANA , AVILÁN LUISANA , MICHELS PAUL A. M.
Published: August 2012

Glycosomes are specialized peroxisomes found in all kinetoplastid organisms. The organelles are unique in harbouring most enzymes of the glycolytic pathway. Matrix proteins, synthesized in the cytosol, cofactors and metabolites have to be transported across the membrane. Recent research onTrypanosoma bruceihas provided insight into how these translocations across the membrane occur, although many details remain to be elucidated. Proteins are imported by a cascade of reactions performed by specialized proteins, called peroxins, in which a cytosolic receptor with bound matrix protein inserts itself in the membrane to deliver its cargo into the organelle and is subsequently retrieved from the glycosome to perform further rounds of import. Bulky solutes, such as cofactors and acyl-CoAs, seem to be translocated by specific transporter molecules, whereas smaller solutes such as glycolytic intermediates probably cross the membrane through pore-forming channels. The presence of such channels is in apparent contradiction with previous results that suggested a low permeability of the glycosomal membrane. We propose 3 possible, not mutually exclusive, solutions for this paradox. Glycosomal glycolytic enzymes have been validated as drug targets against trypanosomatid-borne diseases. We discuss the possible implications of the new data for the design of drugs to be delivered into glycosomes.
Shifting practices and emerging patterns: Telephone service encounters in Shanghai
Authors: Sun Hao
Published: August 2012

This study explores the dynamic nature of language in context, utilizing two sets of comparable Chinese discourse data of telephone service encounters collected in the same community a decade apart. It describes and characterizes current business practices and identifies shifts in discursive practices in light of the patterns observed in the past. Observed changes include constitutive components of the global structure, local realization of the structural elements, and interaction dynamics as a result of changed, redefined contexts and realigned footings. I propose that observed shifts may represent and constitute in part the emergence in the community of the reconstruction, or reshaping, of a more distinctive telephone service encounter (TSE) spoken genre and related discursive features. With the adoption of more recognizable boundary markers, shifts in discursive practice of telephone service encounters in Shanghai may result in openings with distinguishable features from calls made to residences. (Discourse analysis, service encounter, practice, telephone in business, China, spoken genre)*
ExtensiveMycobacterium tuberculosiscirculation in a highly endemic prison and the need for urgent environmental interventions
Authors: SÁNCHEZ A. , HUBER F. D. , MASSARI V. , BARRETO A. , CAMACHO L. A. B. , CESCONI V. , SAAD M. H. , LAROUZE B.
Published: August 2012

Aimed at assessing the circulation ofMycobacterium tuberculosisin a highly endemic prison, this 13-month prospective study was performed on strains isolated from tuberculosis (TB) cases detected passively and actively. We used X-ray screening of newly admitted inmates and mass screening at the beginning of the study and again 1 year later. Of the 94 strains genotyped by restriction fragment-length polymorphism, 79 (84·0%) belonged to one of the 12 identified clusters (2–21 strains each), including two main clusters (18 and 21 cases, respectively). A history of TB treatment was reported in 22/79 (27·8%) clustered cases. Time–space distribution of clustered cases was predominantly consistent with transmission, in micro-epidemics. Given the dominant pattern of exogenous infection and the extensive strain circulation, effective TB control should emphasize reduction of overcrowding and improvement of environmental measures as a complement to detection and treatment of cases.
Fibre intake and evolution of BMI: from pre-pregnancy to postpartum
Authors: Drehmer Michele , Camey Suzi Alves , Nunes Maria Angélica , Duncan Bruce B , Lacerda Mauro , Pinheiro Andréia Poyastro , Schmidt Maria Inês
Published: August 2012

Objective

To evaluate the effect of fibre intake on the evolution of maternal BMI from pregnancy to postpartum and to identify dietary patterns associated with fibre intake.

Design

Cohort study. Food intake was obtained using an FFQ. Focused principal component analysis was used focusing on the variables: postpartum weight retention and total dietary fibre intake. Poisson regression models with robust variance were built in order to measure the effect of fibre intake during the postpartum period on obesity risk.

Setting

Primary care clinics in southern Brazil.

Subjects

Pregnant women (n370) were followed until the 5th month postpartum.

Results

The highest contribution to fibre intake came from the consumption of beans. Consumption of bread and rice indicated a common Brazilian food pattern along with beans. Participants retained a median of 4·4 (interquartile range 0·6, 7·9) kg of weight gained during pregnancy. Obesity risk, defined as an unfavourable evolution of BMI during pregnancy and postpartum, was present in 189 (55·1 %) women. Individual food items did not have an important effect on weight retention. In Poisson regression adjusting for maternal age, pre-pregnancy BMI and total gestational weight gain, inadequate postpartum fibre intake increased obesity risk by 24 % (relative risk = 1·24; 95 % CI 1·05, 1·47).

Conclusions

Important maternal weight retention occurred in these women. Adequate fibre intake may reduce obesity risk in the period following childbirth.
Practices and evaluations of prognostic disclosure for Japanese cancer patients and their families from the family's point of view
Authors: Yoshida Saran , Shiozaki Mariko , Sanjo Makiko , Morita Tatsuya , Hirai Kei , Tsuneto Satoru , Shima Yasuo
Published: August 2012

Objective:

The primary end points of this analysis were to explore 1) the practices of prognostic disclosure for patients with cancer and their family members in Japan, 2) the person who decided on the degree of prognosis communication, and 3) family evaluations of the type of prognostic disclosure.

Method:

Semistructured face-to-face interviews were conducted with 60 bereaved family members of patients with cancer who were admitted to palliative care units in Japan.

Results:

Twenty-five percent of patients and 75% of family members were informed of the predicted survival time of the patient. Thirty-eight percent of family members answered that they themselves decided on to what degree to communicate the prognosis to patients and 83% of them chose not to disclose to patients their prognosis or incurability. In the overall evaluation of prognosis communication, 30% of the participants said that they regretted or felt doubtful about the degree of prognostic disclosure to patients, whereas 37% said that they were satisfied with the degree of prognostic disclosure and 5% said that they had made a compromise. Both in the “prognostic disclosure” group and the “no disclosure” group, there were family members who said that they regretted or felt doubtful (27% and 31%, respectively) and family members who said that they were satisfied with the degree of disclosure (27% and 44%, respectively).

Significance of results:

In conclusion, family members assume the predominant role as the decision-making source regarding prognosis disclosure to patients, and they often even prevent prognostic disclosure to patients. From the perspective of family members, any one type of disclosure is not necessarily the most acceptable choice. Future surveys should explore the reasons why family members agree or disagree with prognostic disclosures to patients and factors correlated with family evaluations.
The vulnerable subject of negligence law
Authors: Stychin Carl F.
Published: August 2012

The approach taken by English courts to the duty of care question in negligence has been subject to harsh criticism in recent years. This article examines this fundamental issue in tort law, drawing upon Canadian and Australian jurisprudence by way of comparison. From this analysis, the concept of vulnerability is developed as a productive means of understanding the duty of care. Vulnerability is of increasing interest in legal and political theory and it is of particular relevance to the law of negligence. In addition to aiding doctrinal coherence, vulnerability – with its focus on relationships and care – has the potential to broaden the way in which the subject of tort law is conceived because it challenges dominant assumptions about autonomy as being prior to the relationships on which it is dependent.
Virtual walls? The law of pseudo-public spaces
Authors: Mac Síthigh Daithí
Published: August 2012

This article considers and assesses pseudo-public spaces, considering both physical and non-physical spaces. Presenting perspectives from law, geography, architecture and communication studies, it is argued that there are links between the conditions pertaining to shopping centres, redeveloped city centres, Internet service providers and websites. Particular attention is paid to unfulfilled claims regarding the promise of new spaces, or inconsistencies as between the form and substance of a given space. The owners of pseudo-public physical spaces use legal tools such as the right to exclude from private property, while the owners of pseudo-public virtual spaces often base the relationship with a user on contractual agreements; in both cases, concepts of fundamental rights are also affected, if not often vindicated. The consequences of these approaches are assessed, drawing on critical legal geography and the history of ‘common carriers’ and other forms of regulation.
The impact of model fidelity on seasonal predictive skill
Authors: Kharin V. V. , Scinocca J. F.
Published: August 2012

The relationship between the quality of a general circulation model's (GCM's) representation of present climate and its predictive skill on seasonal time scales is investigated by a series of GCM experiments. A novel procedure is developed to improve the quality of a GCM's present‐day control climate by applying cyclostationary annually varying run‐time “bias corrections”. Application of this procedure to the Canadian Centre for Climate Modelling and Analysis third generation atmospheric GCM (AGCM3) is shown to result in a significant reduction of time‐mean biases in wind, temperature and humidity fields in its simulation of present‐day climate. Furthermore, it is found that this cyclostationary correction leads to improved variability on seasonal time scales. The ability to improve a GCM's properties in this way allows a careful assessment of the relationship between a model's fidelity and its predictive skill. In this study, the potential predictive skill on seasonal time scales is assessed by performing ensemble simulations with the observed sea surface temperatures and sea‐ice distribution. The analysis indicates that the increase in model fidelity associated with the application of the bias correction results in a general increase in predictive skill on seasonal times scales. To investigate this result further, an additional set of ensemble forecasts are performed with the sign of the bias correction reversed, thereby degrading model fidelity. In this additional experiment the corresponding predictive skill is also degraded. The results of this study have implications with regard to the application and interpretation of model metrics for climate GCMs.
California heat waves in the present and future
Authors: Gershunov Alexander , Guirguis Kristen
Published: August 2012

Current and projected heat waves are examined over California and its sub‐regions in observations and downscaled global climate model (GCM) simulations. California heat wave activity falls into two distinct types: (1) typically dry daytime heat waves and (2) humid nighttime‐accentuated events (Type I and Type II, respectively). The four GCMs considered project Type II heat waves to intensify more with climate change than the historically characteristic Type I events, although both types are projected to increase. This trend is already clearly observed and simulated to various degrees over all sub‐regions of California. Part of the intensification in heat wave activity is due directly to mean warming. However, when one considers non‐stationarity in daily temperature variance, desert heat waves are expected to become progressively and relatively less intense while coastal heat waves are projected to intensify even relative to the background warming. This result generally holds for both types of heat waves across models. Given the high coastal population density and low acclimatization to heat, especially humid heat, this trend bodes ill for coastal communities, jeopardizing public health and stressing energy resources.
Do Langmuir wave packets in the solar wind collapse?
Authors: Graham D. B. , Cairns Iver H. , Prabhakar D. R. , Ergun R. E. , Malaspina D. M. , Bale S. D. , Goetz K. , Kellogg P. J.
Published: August 2012

Intense localized Langmuir waves in the solar wind are often associated with type III solar radio bursts. Wave packets with a Gaussian fall‐off of electric field with distance are shown to be consistent with strong turbulence simulations. The collapse threshold for these Gaussian wave packets is calculated analytically and shown to be consistent with previous estimates and simulations. We then assess whether intense Langmuir events detected by the SWAVES instrument on the twin STEREO spacecraft during type III bursts are consistent with known conditions for wave packet collapse. Eight different type III events are selected and a total of 167 wave packets analyzed. An approximate analysis of the observed spatial scales and electric fields shows that none of the wave packets are consistent with collapse. The electric field structures predicted for collapsing wave packets, based on the nucleation mechanism and extensive three‐dimensional electrostatic and electromagnetic Zakharov simulations, are also fitted to the observed data: about a third of the packets are well fitted by a potential with a Gaussian radial function. Where good fits can be found, the wave packets do not meet the requirements for collapse. Good eigenmode fits are found for wave packets with waveforms well fitted by the structural form of collapsing wave packets. This is because the electric field envelopes of collapsing wave packets and trapped Langmuir eigenmodes are both Hermite‐Gauss functions. This rules out the possibility of wave packet collapse and strong turbulence being important processes in type III source regions.
A 3D hp‐adaptive discontinuous Galerkin method for modeling earthquake dynamics
Authors: Tago J. , Cruz‐Atienza V. M. , Virieux J. , Etienne V. , Sánchez‐Sesma F. J.
Published: August 2012

We introduce a novel scheme, DGCrack, to simulate dynamic rupture of earthquakes in three dimensions based on an hp‐adaptive discontinuous Galerkin method. We solve the velocity‐stress weak formulation of elastodynamic equations on an unstructured tetrahedral mesh with arbitrary mesh refinements (h‐adaptivity) and local approximation orders (p‐adaptivity). Our scheme considers second‐order fault elements (P2) where dynamic‐rupture boundary conditions are enforced throughad hocfluxes across the fault. To model the Coulomb slip‐dependent friction law, we introduce a predictor‐corrector scheme for estimating shear fault tractions, in addition to a special treatment of the normal tractions that guarantees the continuity of fault normal velocities. We verify the DGCrack by comparison with several methods for two spontaneous rupture tests and find excellent agreement (i.e., rupture times RMS errors smaller than 1.0%) provided that one or more fault elements resolve the fault cohesive zone. For a quantitative comparison, we introduce a methodology based on cross‐correlation measurements that provide a simple way to quantify the similarity between solutions. Our verification tests include a 60° dipping normal fault reaching the free surface. The DGCrack method reveals convergence rates close to those of well‐established methods and a numerical efficiency significantly higher than that of similar discontinuous Galerkin approaches. We apply the method to the 1992 Landers‐earthquake fault system in a layered medium, considering heterogeneous initial stress conditions and mesh adaptivities. Our results show that previously proposed dynamic models for the Landers earthquake require a reevaluation in terms of the initial stress conditions that take account of the intricate fault geometry.
Using horizontal transport characteristics to infer an emission height time series of volcanic SO2
Authors: Hughes E. J. , Sparling L. C. , Carn S. A. , Krueger A. J.
Published: August 2012

Characterizing the emission height of sulfur dioxide (SO2) from volcanic eruptions yields information about the strength of volcanic activity, and is crucial for the assessment of possible climate impacts and validation of satellite retrievals of SO2. Sensors such as the Ozone Monitoring Instrument (OMI) on the polar‐orbiting Aura satellite provide accurate maps of the spatial distribution of volcanic SO2, but provide limited information on its vertical distribution. The goal of this work is to explore the possible use of a trajectory model in reconstructing both the temporal activity and injection altitude of volcanic SO2 from OMI column measurements observed far from the volcano. Using observations from the November 2006 eruption of Nyamuragira, back trajectories are run and statistical analyses are computed based on the distance of closest approach to the volcano. These statistical analyses provide information about the emission height time series of SO2 injection from that eruption. It is found that the eruption begins first injecting SO2 into the upper troposphere, between 13 km and 17 km, on November 28th 2006. This is then followed by a slow decay in injection altitude, down to 6 km, over subsequent days. The emission height profile is used to generate an optimal reconstruction based on forward trajectories and compared to OMI SO2 observations. The inferred altitude of the Nyamuragira SO2cloud is also compared to the altitude of sulfate aerosols detected in aerosol backscatter vertical profiles from the Cloud‐Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument aboard the Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO).
Analysis of disk‐resolved OMEGA and CRISM spectral observations of Phobos and Deimos
Authors: Fraeman A. A. , Arvidson R. E. , Murchie S. L. , Rivkin A. , Bibring J.‐P. , Choo T. H. , Gondet B. , Humm D. , Kuzmin R. O. , Manaud N. , Zabalueva E. V.
Published: August 2012

Disk‐resolved observations of Phobos acquired by OMEGA at a range of lighting and viewing geometries were fit with the Hapke photometric function to solve for the single particle phase function and single scattering albedos from 0.4 to 2.5 μm. Single scattering albedos were recovered from CRISM observations of Phobos using the OMEGA derived single particle phase function and are similar to those from OMEGA data. Both the ubiquitous red unit and the blue unit around the crater Stickney exhibit a smooth red‐sloped spectrum, with a steeper continuum in the redder unit. Single scattering albedos retrieved from CRISM measurements of Deimos are similar to those for the red unit on Phobos. Retrieval of single scattering albedos from OMEGA data at 2.8 to 5.0 μm has greater uncertainty, but results in this wavelength range are also consistent with a smooth, red‐sloped spectrum. Phobos' and Deimos' low reflectances, lack of mafic absorption features, and red spectral slopes are incompatible with even highly space weathered chondritic or basaltic compositions. These results, coupled with similarities to laboratory spectra of Tagish Lake (possible D‐type asteroid analog) and CM carbonaceous chondrite meteorites, show that Phobos and Deimos have primitive compositions. If the moons formed in situ rather than by capture of primitive bodies, primitive materials must have been added to the Martian system during accretion or a late stage impact.
Geologic carbon sources may confound ecosystem carbon balance estimates: Evidence from a semiarid steppe in the southeast of Spain
Authors: Rey A. , Etiope G. , Belelli‐Marchesini L. , Papale D. , Valentini R.
Published: August 2012

At a semiarid steppe site located in the SE of Spain, relatively large CO2 emissions were measured that could not be attributed to the ecosystem activity alone. Since the study site was located in a tectonically active area, it was hypothesized that a part of the measured CO2 was of geologic origin. This investigation included a survey of soil CO2 efflux, together with carbon isotope analyses of the CO2 in the soil atmosphere, soil CO2 efflux (i.e., Keeling plots), groundwater and local thermal springs. These measurements confirmed the hypothesis of degassing from geologic sources. In areas with local faults and ancient volcanic structures, soil CO2 efflux rates were significantly higher (i.e., up to 6.3 and 1.4 μmol CO2 m−2 s−1) than measurements in a comparable site that was some distance from fault sites (means of 1.0 and 0.43 μmol CO2 m−2 s−1 in March and June, respectively). The CO2 concentration in the soil atmosphere at the eddy covariance site reached 0.14% v/v at 0.70 m soil depth with a 13C‐enriched isotopic composition (δ13C from −10.2‰ to −16.6‰), consistent with the isotopic composition of the soil CO2 efflux estimated by Keeling plots (i.e., −16.6‰). 13C‐enriched CO2 also occurred in local aquifers, and there was evidence of degassing from deep crust and mantle at regional scale by the helium isotopic ratio in spring waters located about 30 km (R/Ra: 0.12) and 200 km (R/Ra: 0.95) NW of the eddy covariance site. This study highlights the importance of considering CO2 sources of geologic origin when assessing the net ecosystem carbon balance of sites that may possibly be affected by circulation of such CO2‐rich fluids.
Sex determination in beetles: Production of all male progeny by Parental RNAi knockdown of transformer
Authors: Shukla Jayendra Nath , Palli Subba Reddy
Published: August 2012

Sex in insects is determined by a cascade of regulators ultimately controlling sex-specific splicing of a transcription factor, Doublesex (Dsx). We recently identified homolog of dsx in the red flour beetle, Tribolium castaneum (Tcdsx). Here, we report on the identification and characterization of a regulator of Tcdsx splicing in T. castaneum. Two male-specific and one female-specific isoforms of T. castaneum transformer (Tctra) were identified. RNA interference-aided knockdown of Tctra in pupa or adults caused a change in sex from females to males by diverting the splicing of Tcdsx pre-mRNA to male-specific isoform. All the pupa and adults developed from Tctra dsRNA injected final instar larvae showed male-specific sexually dimorphic structures. Tctra parental RNAi caused an elimination of females from the progeny resulting in production of all male progeny. Transformer parental RNAi could be used to produce all male population for use in pest control though sterile male release methods.
Is the Amyloid Hypothesis of Alzheimer's disease therapeutically relevant?
Authors: Teich Andrew F. , Arancio Ottavio
Published: August 2012

The conventional view of AD (Alzheimer's disease) is that much of the pathology is driven by an increased load of β-amyloid in the brain of AD patients (the ‘Amyloid Hypothesis’). Yet, many therapeutic strategies based on lowering β-amyloid have so far failed in clinical trials. This failure of β-amyloid-lowering agents has caused many to question the Amyloid Hypothesis itself. However, AD is likely to be a complex disease driven by multiple factors. In addition, it is increasingly clear that β-amyloid processing involves many enzymes and signalling pathways that play a role in a diverse array of cellular processes. Thus the clinical failure of β-amyloid-lowering agents does not mean that the hypothesis itself is incorrect; it may simply mean that manipulating β-amyloid directly is an unrealistic strategy for therapeutic intervention, given the complex role of β-amyloid in neuronal physiology. Another possible problem may be that toxic β-amyloid levels have already caused irreversible damage to downstream cellular pathways by the time dementia sets in. We argue in the present review that a more direct (and possibly simpler) approach to AD therapeutics is to rescue synaptic dysfunction directly, by focusing on the mechanisms by which elevated levels of β-amyloid disrupt synaptic physiology.
DNA-dependent Oct4–Sox2 interaction and diffusion properties characteristic of the pluripotent cell state revealed by fluorescence spectroscopy
Authors: Lam Chen Sok , Mistri Tapan Kumar , Foo Yong Hwee , Sudhaharan Thankiah , Gan Hui Theng , Rodda David , Lim Leng Hiong , Chou Chai , Robson Paul , Wohland Thorsten , Ahmed Sohail
Published: August 2012

Oct4 and Sox2 are two essential transcription factors that co-regulate target genes for the maintenance of pluripotency. However, it is unclear whether they interact prior to DNA binding or how the target sites are accessed in the nucleus. By generating fluorescent protein fusions of Oct4 and Sox2 that are functionally capable of producing iPSCs (induced pluripotent stem cells), we show that their interaction is dependent on the presence of cognate DNA-binding elements, based on diffusion time, complex formation and lifetime measurements. Through fluorescence correlation spectroscopy, the levels of Oct4 and Sox2 in the iPSCs were quantified in live cells and two diffusion coefficients, corresponding to free and loosely bound forms of the protein, were distinguished. Notably, the fraction of slow-diffusing molecules in the iPSCs was found to be elevated, similar to the profile in embryonic stem cells, probably due to a change in the nuclear milieu during reprogramming. Taken together, these findings have defined quantitatively the amount of proteins pertinent to the pluripotent state and revealed increased accessibility to the underlying DNA as a mechanism for Oct4 and Sox2 to find their target binding sites and interact, without prior formation of heterodimer complexes.
Evidence for a link between histone deacetylation and Ca2+ homoeostasis in sphingosine-1-phosphate lyase-deficient fibroblasts
Authors: Ihlefeld Katja , Claas Ralf Frederik , Koch Alexander , Pfeilschifter Josef M. , Meyer zu Heringdorf Dagmar
Published: August 2012

Embryonic fibroblasts from S1P (sphingosine-1-phosphate) lyase-deficient mice [Sgpl1−/− MEFs (mouse embryonic fibroblasts)] are characterized by intracellular accumulation of S1P, elevated cytosolic [Ca2+]i and enhanced Ca2+ storage. Since S1P, produced by sphingosine kinase 2 in the nucleus of MCF-7 cells, inhibited HDACs (histone deacetylases) [Hait, Allegood, Maceyka, Strub, Harikumar, Singh, Luo, Marmorstein, Kordula, Milstein et al. (2009) Science 325, 1254–1257], in the present study we analysed whether S1P accumulated in the nuclei of S1P lyase-deficient MEFs and caused HDAC inhibition. Interestingly, nuclear concentrations of S1P were disproportionally elevated in Sgpl1−/− MEFs. HDAC activity was reduced, acetylation of histone 3-Lys9 was increased and the HDAC-regulated gene p21 cyclin-dependent kinase inhibitor was up-regulated in these cells. Furthermore, the expression of HDAC1 and HDAC3 was reduced in Sgpl1−/− MEFs. In wild-type MEFs, acetylation of histone 3-Lys9 was increased by the S1P lyase inhibitor 4-deoxypyridoxine. The non-specific HDAC inhibitor trichostatin A elevated basal [Ca2+]i and enhanced Ca2+ storage, whereas the HDAC1/2/3 inhibitor MGCD0103 elevated basal [Ca2+]i without influence on Ca2+ storage in wild-type MEFs. Overexpression of HDAC1 or HDAC2 reduced the elevated basal [Ca2+]i in Sgpl1−/− MEFs. Taken together, S1P lyase-deficiency was associated with elevated nuclear S1P levels, reduced HDAC activity and down-regulation of HDAC isoenzymes. The decreased HDAC activity in turn contributed to the dysregulation of Ca2+ homoeostasis, particularly to the elevated basal [Ca2+]i, in Sgpl1−/− MEFs.
Preoperative Sclerotherapy Using Sodium Tetradecyl Sulphate (Fibro-Vein™) Can Assist in the Management of Vertebral Hemangiomas
Authors: Damodaran Omprakash , McAuliffe Will , Wong George , McCloskey Eamonn , Lee Gabriel
Published: August 2012

Vertebral hemangiomas are benign lesions accounting for 2 to 3% of all spinal tumors. They are usually asymptomatic and found incidentally on imaging. Uncommonly, vertebral hemangiomas with significant epidural extension can result in radiculopathy or spinal cord compression. Decompressive surgery with or without stabilization is often required when neurological deficits are present. However, surgery can be associated with massive hemorrhage as these tumors are hypervascular. Preoperative embolization and sclerotherapy are well-known management strategies used to minimize intraoperative bleeding and improve symptoms. Recently, the use of sclerosants such as ethanol has decreased, due to reported complications such as Brown–Sequard syndrome. We describe the use of sodium tetradecyl sulfate (Fibro-Vein™, STD Pharmaceutical, Hereford, UK) as an effective alternative to ethanol in the preoperative management of vertebral hemangiomas. To our knowledge, this has not been previously reported. In three patients, we demonstrated minimal intraoperative blood loss using a combination of preoperative embolization of arterial feeders and sclerotherapy with sodium tetradecyl sulfate to control and secure venous drainage. No patients developed complications related to the procedure. In addition to minimal blood loss, a clear dissection plane was also noted intraoperatively.
Laminoplasty for Cervical Myelopathy
Authors: Ito Manabu , Nagahama Ken
Published: August 2012

This article reviews cervical laminoplasty. The origin of cervical laminoplasty dates back to cervical laminectomy performed in Japan ~50 years ago. To overcome poor surgical outcomes of cervical laminectomy, many Japanese orthopedic spine surgeons devoted their lives to developing better posterior decompression procedures for the cervical spine. Thanks to the development of a high-speed surgical burr, posterior decompression procedures for the cervical spine showed vast improvement from the 1970s to the 1980s, and the original form of cervical laminoplasty was determined. Since around 2000, surgeons performing cervical laminoplasty have been adopting less invasive procedures for the posterior cervical muscle structures so as to minimize postoperative axial neck pain and obtain better functional outcomes of the cervical spine. This article covers the history of cervical laminoplasty, surgical procedures, the benefits and limitation of this procedure, and surgery-related complications.
The neutron imaging diagnostic at NIF (invited)
Authors: Merrill F. E. , Bower D. , Buckles R. , Clark D. D. , Danly C. R. , Drury O. B. , Dzenitis J. M. , Fatherley V. E. , Fittinghoff D. N. , Gallegos R. , Grim G. P. , Guler N. , Loomis E. N. , Lutz S. , Malone R. M. , Martinson D. D. , Mares D. , Morley D. J. , Morgan G. L. , Oertel J. A. , Tregillis I. L. , Volegov P. L. , Weiss P. B. , Wilde C. H. , Wilson D. C.
Published: August 2012

A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of Inertial Confinement Fusion (ICF) implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6–12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.
The nonlinear stability of the trivial solution to the Maxwell-Born-Infeld system
Authors: Speck Jared
Published: August 2012

In this article, we use an electromagnetic gauge-free framework to establish the existence of small-data global solutions to the Maxwell-Born-Infeld (MBI) system on the Minkowski spacetime background in 1+3 dimensions. Because the nonlinearities in the system have a special null structure, we are also able to show that these solutions decay at least as fast as solutions to the linear Maxwell-Maxwell system. In addition, we show that on any Lorentzian manifold, the MBI system is hyperbolic in the interior of the field-strength regime in which its Lagrangian is real-valued.
Laser-driven electron beamlines generated by coupling laser-plasma sources with conventional transport systems
Authors: Antici P. , Bacci A. , Benedetti C. , Chiadroni E. , Ferrario M. , Rossi A. R. , Lancia L. , Migliorati M. , Mostacci A. , Palumbo L. , Serafini L.
Published: August 2012

Laser-driven electron beamlines are receiving increasing interest from the particle accelerator community. In particular, the high initial energy, low emittance, and high beam current of the plasma based electron source potentially allow generating much more compact and bright particle accelerators than what conventional accelerator technology can achieve. Using laser-generated particles as injectors for generating beamlines could significantly reduce the size and cost of accelerator facilities. Unfortunately, several features of laser-based particle beams need still to be improved before considering them for particle beamlines and thus enable the use of plasma-driven accelerators for the multiple applications of traditional accelerators. Besides working on the plasma source itself, a promising approach to shape the laser-generated beams is coupling them with conventional accelerator elements in order to benefit from both a versatile electron source and a controllable beam. In this paper, we perform start-to-end simulations to generate laser-driven beamlines using conventional accelerator codes and methodologies. Starting with laser-generated electrons that can be obtained with established multi-hundred TW laser systems, we compare different options to capture and transport the beams. This is performed with the aim of providing beamlines suitable for potential applications, such as free electron lasers. In our approach, we have analyzed which parameters are critical at the source and from there evaluated different ways to overcome these issues using conventional accelerator elements and methods. We show that electron driven beamlines are potentially feasible, but exploiting their full potential requires extensive improvement of the source parameters or innovative technological devices for their transport and capture.
Simultaneous imaging electron- and ion-feature Thomson scattering measurements of radiatively heated Xe
Authors: Pollock B. B. , Meinecke J. , Kuschel S. , Ross J. S. , Shaw J. L. , Stoafer C. , Divol L. , Tynan G. R. , Glenzer S. H.
Published: August 2012

Uniform density and temperature Xe plasmas have been produced over >4 mm scale-lengths using x-rays generated in a cylindrical Pb cavity. The cavity is 750 μm in depth and diameter, and is heated by a 300 J, 2 ns square, 1054 nm laser pulse focused to a spot size of 200 μm at the cavity entrance. The plasma is characterized by simultaneous imaging Thomson scattering measurements from both the electron and ion scattering features. The electron feature measurement determines the spatial electron density and temperature profile, and using these parameters as constraints in the ion feature analysis allows an accurate determination of the charge state of the Xe ions. The Thomson scattering probe beam is 40 J, 200 ps, and 527 nm, and is focused to a 100 μm spot size at the entrance of the Pb cavity. Each system has a spatial resolution of 25 μm, a temporal resolution of 200 ps (as determined by the probe duration), and a spectral resolution of 2 nm for the electron feature system and 0.025 nm for the ion feature system. The experiment is performed in a Xe filled target chamber at a neutral pressure of 3–10 Torr, and the x-rays produced in the Pb ionize and heat the Xe to a charge state of 20±4 at up to 200 eV electron temperatures.
Influence of non-universal effects on dynamical scaling in driven polymer translocation
Authors: Ikonen T. , Bhattacharya A. , Ala-Nissila T. , Sung W.
Published: August 2012

We study the dynamics of driven polymer translocation using both molecular dynamics (MD) simulations and a theoretical model based on the non-equilibrium tension propagation on the cis side subchain. We present theoretical and numerical evidence that the non-universal behavior observed in experiments and simulations are due to finite chain length effects that persist well beyond the relevant experimental and simulation regimes. In particular, we consider the influence of the pore-polymer interactions and show that they give a major contribution to the non-universal effects. In addition, we present comparisons between the theory and MD simulations for several quantities, showing extremely good agreement in the relevant parameter regimes. Finally, we discuss the potential limitations of the present theories.
The J = 2 ortho levels of the v = 0 to 6 np singlet Rydberg series of molecular hydrogen revisited
Authors: Glass-Maujean M. , Schmoranzer H. , Haar I. , Knie A. , Reiss P. , Ehresmann A.
Published: August 2012

The energies of the J = 2 ortho levels of the v = 0 to 6 Rydberg np singlet series of molecular hydrogen with absolute intensities of the R(1) and P(3) absorption lines were measured by a high-resolution synchrotron radiation experiment and calculated through a full ab initio multi-channel quantum defect approach.
Dynamics of the defect-mediated desorption of alkali halide surfaces
Authors: Szymonski M. , Droba A. , Struski P. , Krok F.
Published: August 2012

Dynamic processes leading to desorption of Rb and I atoms from the RbI (100) surface co-irradiated with 1 keV electrons and visible light (with a wavelength corresponding to the F-center absorption band) have been studied by means of mass-selected time-of-flight (TOF) spectroscopy. Depending on the sample temperature, substantial enhancement of the desorption yield as well as pronounced changes in the TOF spectra of the emitted atoms have been found. The TOF spectra of halogen atoms consist of two components: the thermal (which can be fitted with Maxwellian distribution) and the non-thermal one. The non-thermal peak is temperature-independent. There is no non-thermal component for alkali atoms. The comparison of TOF spectra for I atoms emitted from electron bombarded sample with and without simultaneous light irradiation indicates that the yield increase is caused by thermally desorbed atoms, while the non-thermal peak remains unchanged. Presented results confirm well the predictions of the theoretical model of desorption proposed earlier, known as the defect-mediated (F and H center) desorption of alkali halide.