bluuebunny/crossref_metadata_2025 huggingface dataset:
High prevalence of smoking among patients with suspected tuberculosis in South Africa
Authors: Brunet L. , Pai M. , Davids V. , Ling D. , Paradis G. , Lenders L. , Meldau R. , van Zyl Smit R. , Calligaro G. , Allwood B. , Dawson R. , Dheda K.
Published: December 2010

There is growing evidence that tobacco smoking is an important risk factor for tuberculosis (TB). There are no data validating the accuracy of self-reported smoking in TB patients and limited data about the prevalence of smoking in TB patients from high-burden settings.

We performed a cross-sectional analysis of 500 patients with suspected TB in Cape Town, South Africa. All underwent comprehensive diagnostic testing. The accuracy of their self-reported smoking status was determined against serum cotinine levels.

Of the 424 patients included in the study, 56 and 60% of those with active and latent TB infection (LTBI), respectively, were current smokers. Using plasma cotinine as a reference standard, the sensitivity of self-reported smoking was 89%. No statistically significant association could be found between smoking and active TB or LTBI.

In Cape Town, the prevalence of smoking among patients with suspected and confirmed TB was much higher than in the general South African population. Self-reporting is an accurate measure of smoking status. These results suggest the need to actively incorporate tobacco cessation programmes into TB services in South Africa.
Chromosomal mapping of rRNA genes, core histone genes and telomeric sequences in Brachidontes puniceus and Brachidontes rodriguezi (Bivalvia, Mytilidae)
Authors: Pérez-García Concepción , Guerra-Varela Jorge , Morán Paloma , Pasantes Juan J
Published: December 2010

Background

Chromosome rearrangements are an important part of the speciation process in many taxa. The study of chromosome evolution in bivalves is hampered by the absence of clear chromosomal banding patterns and the similarity in both chromosome size and morphology. For this reason, obtaining good chromosome markers is essential for reliable karyotypic comparisons. To begin this task, the chromosomes of the mussels Brachidontes puniceus and B. rodriguezi were studied by means of fluorochrome staining and fluorescent in situ hybridization (FISH).

Results

Brachidontes puniceus and B. rodriguezi both have 2n = 32 chromosomes but differing karyotype composition. Vertebrate-type telomeric sequences appear at both ends of every single chromosome. B. puniceus presents a single terminal major rRNA gene cluster on a chromosome pair while B. rodriguezi shows two. Both mussels present two 5S rDNA and two core histone gene clusters intercalary located on the long arms of two chromosome pairs. Double and triple-FISH experiments demonstrated that one of the 5S rDNA and one of the major rDNA clusters appear on the same chromosome pair in B. rodriguezi but not in B. puniceus. On the other hand, the second 5S rDNA cluster is located in one of the chromosome pairs also bearing one of the core histone gene clusters in the two mussel species.

Conclusion

Knowledge of the chromosomal distribution of these sequences in the two species of Brachidontes is a first step in the understanding of the role of chromosome changes on bivalve evolution.
Genetic study of the hepcidin gene (HAMP) promoter and functional analysis of the c.-582A > G variant
Authors: Parajes Silvia , González-Quintela Arturo , Campos Joaquín , Quinteiro Celsa , Domínguez Fernando , Loidi Lourdes
Published: December 2010

Background

Hepcidin acts as the main regulator of iron homeostasis through regulation of intestinal absorption and macrophage release. Hepcidin deficiency causes iron overload whereas its overproduction is associated with anaemia of chronic diseases. The aims of the study were: to identify genetic variants in the hepcidin gene (HAMP) promoter, to asses the associations between the variants found and iron status parameters, and to functionally study the role on HAMP expression of the most frequent variant.

Results

The sequencing of HAMP promoter from 103 healthy individuals revealed two genetic variants: The c.-153C > T with a frequency of 0.014 for allele T, which is known to reduce hepcidin expression and the c.-582A > G with a 0.218 frequency for allele G. In an additional group of 224 individuals, the c.-582A > G variant genotype showed no association with serum iron, transferrin or ferritin levels.

The c.-582G HAMP promoter variant decreased the transcriptional activity by 20% compared to c.-582A variant in cells from the human hepatoma cell line HepG2 when cotransfected with luciferase reporter constructs and plasmid expressing upstream stimulatory factor 1 (USF1) and by 12-14% when cotransfected with plasmid expressing upstream stimulatory factor 2 (USF2).

Conclusions

The c.-582A > G HAMP promoter variant is not associated with serum iron, transferrin or ferritin levels in the healthy population. The in vitro effect of the c.-582A > G variant resulted in a small reduction of the gene transactivation by allele G compared to allele A. Therefore the effect of the variant on the hepcidin levels in vivo would be likely negligible. Finally, the c.-153C > T variant showed a frequency high enough to be considered when a genetic analysis is done in iron overload patients.
Effects of site-directed mutagenesis of mglA on motility and swarming of Myxococcus xanthus
Authors: Fremgen Sarah A , Burke Neal S , Hartzell Patricia L
Published: December 2010

Background

ThemglAgene from the bacteriumMyxococcus xanthusencodes a 22kDa protein related to the Ras superfamily of monomeric GTPases. MglA is required for the normal function of A-motility (adventurous), S-motility (social), fruiting body morphogenesis, and sporulation. MglA and its homologs differ from all eukaryotic and other prokaryotic GTPases because they have a threonine (Thr78) in place of the highly conserved aspartate residue of the consensus PM3 (phosphate-magnesium binding) region. To identify residues critical for MglA function or potential protein interactions, and explore the function of Thr78, the phenotypes of 18mglAmutants were characterized.

Results

Nine mutants, with mutations predicted to alter residues that bind the guanine base or coordinate magnesium, did not produce detectable MglA. As expected, these mutants were mot-dev-because MglA is essential for these processes. Of the remaining nine mutants, seven showed a wild-type distribution pattern for MglA but fell into two categories with regard to function. Five of the seven mutants exhibited mild phenotypes, but two mutants, T78D and P80A, abolished motility and development. The localization pattern of MglA was abolished in two mutants that were mot-spo-and dev-. These two mutants were predicted to alter surface residues at Asp52 and Thr54, which suggests that these residues are critical for proper localization and may define a protein interaction site. Improving the consensus match with Ras at Thr78 abolished function of MglA. Only the conservative serine substitution was tolerated at this position. Merodiploid constructs revealed that a subset of alleles, includingmglAD52A, were dominant and also illustrated that changing the balance of MglA and its co-transcribed partner, MglB, affects A-motility.

Conclusion

Our results suggest that GTP binding is critical for stability of MglA because MglA does not accumulate in mutants that cannot bind GTP. The threonine in PM3 of MglA proteins represents a novel modification of the highly conserved GTPase consensus at this position. The requirement for a hydroxyl group at this position may indicate that MglA is subject to modification under certain conditions. Proper localization of MglA is critical for both motility and development and likely involves protein interactions mediated by residues Asp52 and Thr54.
Interaction of the heterotrimeric G protein alpha subunit SSG-1 of Sporothrix schenckii with proteins related to stress response and fungal pathogenicity using a yeast two-hybrid assay
Authors: Pérez-Sánchez Lizaida , González Elizabeth , Colón-Lorenzo Emilee E , González-Velázquez Waleska , González-Méndez Ricardo , Rodríguez-del Valle Nuri
Published: December 2010

Background

Important biological processes require selective and orderly protein-protein interactions at every level of the signalling cascades. G proteins are a family of heterotrimeric GTPases that effect eukaryotic signal transduction through the coupling of cell surface receptors to cytoplasmic effector proteins. They have been associated with growth and pathogenicity in many fungi through gene knock-out studies. In Sporothrix schenckii, a pathogenic, dimorphic fungus, we previously identified a pertussis sensitive G alpha subunit, SSG-1. In this work we inquire into its interactions with other proteins.

Results

Using the yeast two-hybrid technique, we identified protein-protein interactions between SSG-1 and other important cellular proteins. The interactions were corroborated using co-immuneprecipitation. Using these techniques we identified a Fe/Mn superoxide dismutase (SOD), a glyceraldehyde-3-P dehydrogenase (GAPDH) and two ion transport proteins, a siderophore-iron transporter belonging to the Major Facilitator Superfamily (MFS) and a divalent-cation transporter of the Nramp (n atural r esistance-a ssociated m acrophage p rotein) family as interacting with SSG-1. The cDNA's encoding these proteins were sequenced and bioinformatic macromolecular sequence analyses were used for the correct classification and functional assignment.

Conclusions

This study constitutes the first report of the interaction of a fungal G alpha inhibitory subunit with SOD, GAPDH, and two metal ion transporters. The identification of such important proteins as partners of a G alpha subunit in this fungus suggests possible mechanisms through which this G protein can affect pathogenicity and survival under conditions of environmental stress or inside the human host. The two ion transporters identified in this work are the first to be reported in S. schenckii and the first time they are identified as interacting with fungal G protein alpha subunits. The association of G protein alpha subunits to transport molecules reinforces the role of G proteins in the response to environmental signals and also highlights the involvement of fungal G protein alpha subunits in nutrient sensing in S. schenckii. These interactions suggest that these permeases could function as transceptors for G proteins in fungi.
Patient safety in out-of-hours primary care: a review of patient records
Authors: Smits Marleen , Huibers Linda , Kerssemeijer Brian , de Feijter Eimert , Wensing Michel , Giesen Paul
Published: December 2010

Background

Most patients receive healthcare in primary care settings, but relatively little is known about patient safety. Out-of-hours contacts are of particular importance to patient safety. Our aim was to examine the incidence, types, causes, and consequences of patient safety incidents at general practice cooperatives for out-of-hours primary care and to examine which factors were associated with the occurrence of patient safety incidents.

Methods

A retrospective study of 1,145 medical records concerning patient contacts with four general practice cooperatives. Reviewers identified records with evidence of a potential patient safety incident; a physician panel determined whether a patient safety incident had indeed occurred. In addition, the panel determined the type, causes, and consequences of the incidents. Factors associated with incidents were examined in a random coefficient logistic regression analysis.

Results

In 1,145 patient records, 27 patient safety incidents were identified, an incident rate of 2.4% (95% CI: 1.5% to 3.2%). The most frequent incident type was treatment (56%). All incidents had at least partly been caused by failures in clinical reasoning. The majority of incidents did not result in patient harm (70%). Eight incidents had consequences for the patient, such as additional interventions or hospitalisation. The panel assessed that most incidents were unlikely to result in patient harm in the long term (89%). Logistic regression analysis showed that age was significantly related to incident occurrence: the likelihood of an incident increased with 1.03 for each year increase in age (95% CI: 1.01 to 1.04).

Conclusion

Patient safety incidents occur in out-of-hours primary care, but most do not result in harm to patients. As clinical reasoning played an important part in these incidents, a better understanding of clinical reasoning and guideline adherence at GP cooperatives could contribute to patient safety.
The challenge of diagnosing Plasmodium ovale malaria in travellers: report of six clustered cases in french soldiers returning from West Africa
Authors: de Laval Franck , Oliver Manuela , Rapp Christophe , Pommier de Santi Vincent , Mendibil Alexandre , Deparis Xavier , Simon Fabrice
Published: December 2010

Background

Plasmodium ovale is responsible for 5% of imported malaria in French travellers. The clinical and biological features of six clustered cases of P. ovale malaria in an army unit of 62 French soldiers returning from the Ivory Coast are reported.

Case report

All patients were symptomatic and developed symptoms on average 50 days after their return and 20 days after the end of chemoprophylaxis (doxycycline). Clinical features included fever (6/6), mostly tertian (4/6), aches (6/6), nausea (3/6), abdominal pain (2/6), diarrhoea (2/6), or cough (2/6). Thrombocytopaenia was lower than 100,000/mm3 in half the cases only, and the haemoglobin count was normal for all patients. The diagnosis was made after at least three thick and thin blood smear searches. Parasitaemia was always lower than 0.5%. All rapid diagnostic tests were negative for HRP2 and pLDH antigens.

Discussion

Plasmodium ovale malaria is currently a problem to diagnose in travellers, notably in French soldiers returning from the Ivory Coast. Early attempts at diagnosis are difficult due to the lack of specific clinical features, the rarity of biological changes and the poor sensitivity of diagnostic tools to detect low parasitaemia. Thus, the diagnosis is commonly delayed or missed. Physicians should be aware of this diagnostic challenge to avoid relapses and provide prompt and adequate treatment with chloroquine and radical cure with primaquine.
Production and purification of VP2 protein of porcine parvovirus expressed in an insect-baculovirus cell system
Authors: Zhou Hongchao , Yao Guizhe , Cui Shangjin
Published: December 2010

The porcine parvovirus (PPV) VP2 protein was expressed in an insect-baculovirus cell system and was purified using Ni-NTA affinity column chromatography. The recombinant 6-His-tagged VP2 protein with molecular mass (Mr) of about 64 kDa was detected by anti-his antibody and anti-PPV serum. Electron microscopy showed that the purified VP2 protein assembled into spherical particles with diameters ranging from 20 to 22 nm. The expressed VP2 was antigenically similar to the native capsid protein according to HA and a Western blotting assay performed with polyclonal antibodies collected from an outbreak of PPV in one farm. This study provides a foundation for the application of VP2 protein in the clinical diagnosis of PPV or in the vaccination against PPV in the future.
Management of nanomaterials safety in research environment
Authors: Groso Amela , Petri-Fink Alke , Magrez Arnaud , Riediker Michael , Meyer Thierry
Published: December 2010

Despite numerous discussions, workshops, reviews and reports about responsible development of nanotechnology, information describing health and environmental risk of engineered nanoparticles or nanomaterials is severely lacking and thus insufficient for completing rigorous risk assessment on their use. However, since preliminary scientific evaluations indicate that there are reasonable suspicions that activities involving nanomaterials might have damaging effects on human health; the precautionary principle must be applied. Public and private institutions as well as industries have the duty to adopt preventive and protective measures proportionate to the risk intensity and the desired level of protection. In this work, we present a practical, 'user-friendly' procedure for a university-wide safety and health management of nanomaterials, developed as a multi-stakeholder effort (government, accident insurance, researchers and experts for occupational safety and health). The process starts using a schematic decision tree that allows classifying the nano laboratory into three
hazard
classes similar to a control banding approach (from Nano 3 - highest hazard to Nano1 - lowest hazard). Classifying laboratories into
risk
classes would require considering actual or potential exposure to the nanomaterial as well as statistical data on health effects of exposure. Due to the fact that these data (as well as exposure limits for each individual material) are not available, risk classes could not be determined. For each hazard level we then provide a list of required risk mitigation measures (technical, organizational and personal). The target 'users' of this safety and health methodology are researchers and safety officers. They can rapidly access the precautionary hazard class of their activities and the corresponding adequate safety and health measures. We succeed in convincing scientist dealing with nano-activities that adequate safety measures and management are promoting innovation and discoveries by ensuring them a safe environment even in the case of very novel products. The proposed measures are not considered as constraints but as a support to their research. This methodology is being implemented at the Ecole Polytechnique de Lausanne in over 100 research labs dealing with nanomaterials. It is our opinion that it would be useful to other research and academia institutions as well.
Analytic signals of gravity gradient tensor and their application to estimate source location
Authors: Beiki Majid
Published: December 2010

The analytic signal concept can be applied to gravity gradient tensor data in three dimensions. Within the gravity gradient tensor, the horizontal and vertical derivatives of gravity vector components are Hilbert transform pairs. Three analytic signal functions then are introduced along [Formula: see text]-, [Formula: see text]-, and [Formula: see text]-directions. The amplitude of the first vertical derivative of the analytic signals in [Formula: see text]- and [Formula: see text]-directions enhances the edges of causative bodies. The directional analytic signals are homogenous and satisfy Euler’s homogeneity equation. The application of directional analytic signals to Euler deconvolution on generic models demonstrates their ability to locate causative bodies. One of the advantages of this method is that it allows the automatic identification of the structural index from solving three Euler equations derived from the gravity gradient tensor for a collection of data points in a window. The other advantage is a reduction of interference effects from neighboring sources by differentiation of the directional analytic signals in [Formula: see text]-, [Formula: see text]-, and [Formula: see text]-directions. Application of the method is demonstrated on gravity gradient tensor data in the Vredefort impact structure, South Africa.
Imaging the sea surface using a dual-sensor towed streamer
Authors: Orji Okwudili , Söllner Walter , Gelius Leiv Jacob
Published: December 2010

Sea-surface profile and reflection coefficient estimates are vital input parameters to various seismic data processing applications. The common assumption of a flat sea surface when processing seismic data can lead to misinterpretations and mislocations of events. A new method of imaging the sea surface from decomposed wavefields has been developed. Wavefield separation is applied to the data acquired by a towed dual-sensor streamer containing collocated pressure and vertical particle velocity sensors to obtain upgoing and downgoing wavefields of the related sensors. Time-gated upgoing and downgoing wavefields corresponding to a given sensor are then extrapolated to the sea surface where an imaging condition is applied so that the time-invariant shape of the sea surface can be recovered. By sliding the data time-window, the temporal changes of the sea surface can be correspondingly estimated. Ray tracing and finite-difference methods were used to generate different controlled data sets used in this feasibility study to demonstrate the imaging principle and to test the image accuracy. The method was also tested on a first field data example of a marginal weather line from the North Sea.
Multidimensional inversion of loop-loop frequency-domain EM data for resistivity and magnetic susceptibility
Authors: Sasaki Yutaka , Kim Jung-Ho , Cho Seong-Jun
Published: December 2010

Electromagnetic (EM) induction measurements are affected by resistivity and magnetic susceptibility. Thus, inverting EM data for resistivity alone can give misleading models if susceptible effects are strong. An inversion algorithm is presented to simultaneously recover multidimensional distributions of resistivity and susceptibility from various types of loop-loop frequency-domain EM data. The algorithm adopts a staggered-grid finite-difference method for the 3D forward solutions and computes the sensitivities with respect to resistivity and susceptibility from the forward solutions using the reciprocity principle. The algorithm is tested on synthetic data sets from ground-based small-loop, airborne, and Slingram EM surveys. It is shown that the simultaneous inversion of the small-loop EM data collected at a singleheight is unstable and likely to produce unreliable susceptibility models because the effect of susceptibility is nearly independent of the frequency. However, if the data are obtained for multiple heights or different loop configurations, simultaneous inversion can produce more reliable susceptibility and resistivity models even if the data are contaminated by offset errors. It is also shown that although the simultaneous inversion of airborne EM data is relatively stable, adding data obtained at different heights helps to increase the reliability of the resistivity and susceptibility models. Among the loop-loop EM methods discussed here, the Slingram method is relatively insensitive to susceptibility anomalies and thus cannot be used to recover the susceptibility distribution via inversion even if the data are obtained using different loop configurations.
On the selection of reference velocities for split-step Fourier and generalized-screen migration methods
Authors: Chen Jing-Bo
Published: December 2010

Split-step Fourier and generalized-screen migration methods are approximations with separation of variables to the one-way wave operator, in which the separation of space and wavenumber variables makes it possible to use the discrete fast Fourier transform to achieve computational efficiency. Both methods require the selection of reference velocities. Different choices of reference velocities lead to different velocity perturbations, and the smaller the velocity perturbations, the better the final image quality. The benefits of selecting a more representative reference velocity for the split-step Fourier method can be extended to the generalized-screen method by removing the limitation on the reference velocity for the generalized-screen method. Numerical experiments on the Marmousi model demonstrate the improvement of imaging by using an average velocity instead of the minimum velocity as the reference velocity for the generalized-screen method.
Vegetative phase change is mediated by a leaf-derived signal that represses the transcription of miR156
Authors: Yang Li , Conway Susan R. , Poethig R. Scott
Published: December 2010

Vegetative phase change in Arabidopsis is regulated by miR156, a microRNA that promotes the expression of the juvenile phase and represses the expression of the adult phase. miR156 is expressed at a very high level early in shoot development and then decreases, leading to the onset of the adult phase. To determine the source of the factors that regulate vegetative phase change, we examined the effect of root and leaf ablation on the timing of this transition. Ablation of the root system or cotyledons had no effect on the timing of vegetative phase change, but ablation of leaf primordia delayed this transition in a miR156-dependent fashion. This treatment produced an increase in the overall abundance of miR156, which was attributable to an increase in the transcription of some, but not all, of the miR156 genes in Arabidopsis, and decreased the expression of SPL genes regulated by miR156. miR156 levels were also elevated by leaf ablation in Nicotiana benthamiana and in rejuvenating shoot apices of maize cultured in vitro. We conclude that vegetative phase change is initiated by a signal(s) produced by leaf primordia, which acts by repressing the transcription of specific members of the miR156 gene family.
Binary Payment Schemes: Moral Hazard and Loss Aversion
Authors: Herweg Fabian , Müller Daniel , Weinschenk Philipp
Published: December 2010

We modify the principal-agent model with moral hazard by assuming that the agent is expectation-based loss averse according to Kőoszegi and Rabin (2006, 2007). The optimal contract is a binary payment scheme even for a rich performance measure, where standard preferences predict a fully contingent contract. The logic is that, due to the stochastic reference point, increasing the number of different wages reduces the agent's expected utility without providing strong additional incentives. Moreover, for diminutive occurrence probabilities for all signals the agent is rewarded with the fixed bonus if his performance exceeds a certain threshold. (JEL D82, D86, J41, M52, M12)
Histopathological findings in varicose veins following bipolar radiofrequency-induced thermotherapy – results of an ex vivo experiment
Authors: Reich-Schupke S , Mumme A , Stücker M
Published: December 2010

Objective

To describe the histopathological changes of the vein wall caused by bipolar radiofrequency-induced thermotherapy (RFITT), and to examine influence of power and application time on the histopathological changes.

Material and methods

Twenty vein specimens atraumatically extracted near the saphenofemoral junction were treated by RFITT ex vivo. RFITT was applied with fixed (2 seconds) and varied (up to an impedance of 400 Ω) application time and increasing power (5, 10, 15, 20, 25 W). Specimens were processed histologically.

Results

RFITT induced coagulation of collagen bundles, shrinking of muscles, splitting and necrosis of the vein wall. Circumferential necrosis of intima and media was reached by a power of 20–25 W and an application time up to an impedance of 400 Ω. Only heterogeneous necrosis of intima and media in parts of the vessel was reached by lower power with long application time.

Conclusion

A homogeneous necrosis of the circumferential vein wall needs high power and sufficient application time.
Experiments and Numerical Simulations of Horizontal Two-Phase Flow Regimes Using an Interfacial Area Density Model
Authors: Höhne Thomas , Vallée Christophe
Published: December 2010

Stratified two-phase flow regimes can occur in the main cooling lines of Pressurized Water Reactors, Chemical plants and Oil pipelines. A relevant problem occurring is the development of wavy stratified flows, which can lead to slug generation. In the last decade, stratified flows have increasingly been modelled with computational fluid dynamics (CFD) codes. In CFD, closure models are required that must be validated. Recent improvements of the multiphase flow modelling in the ANSYS CFX code, now make it possible to simulate these mechanisms in detail. In order to validate existing and further developed multiphase flow models, a high spatial and temporal resolution of measurement data are required. For the experimental investigation of co-current air/water flows, the HA WAC (Horizontal Air/Water Channel) was built. The channel allows in particular the study of air/water slug flow under atmospheric pressure. Parallel to the experiments, CFD calculations were carried out. The two-fluid model was applied with a special turbulence damping procedure at the free surface. An Algebraic Interfacial Area Density (AIAD) model based on the implemented mixture model was introduced, which allows the detection of the morphological form of the two-phase flow and the corresponding switching via a blending function of each correlation from one object pair to another. As a result, this model can distinguish between bubbles, droplets and the free surface using the local value of the volume fraction of the liquid phase. The behaviour of slug generation and propagation was qualitatively reproduced by the simulation, while local deviations require a continuation of the work.
Overaccumulation of the chloroplast antisense RNA AS5 is correlated with decreased abundance of 5S rRNA in vivo and inefficient 5S rRNA maturation in vitro
Authors: Sharwood Robert E. , Hotto Amber M. , Bollenbach Thomas J. , Stern David B.
Published: December 2010

Post-transcriptional regulation in the chloroplast is exerted by nucleus-encoded ribonucleases and RNA-binding proteins. One of these ribonucleases is RNR1, a 3′-to-5′ exoribonuclease of the RNase II family. We have previously shown that Arabidopsis rnr1-null mutants exhibit specific abnormalities in the expression of the rRNA operon, including the accumulation of precursor 23S, 16S, and 4.5S species and a concomitant decrease in the mature species. 5S rRNA transcripts, however, accumulate to a very low level in both precursor and mature forms, suggesting that they are unstable in the rnr1 background. Here we demonstrate that rnr1 plants overaccumulate an antisense RNA, AS5, that is complementary to the 5S rRNA, its intergenic spacer, and the downstream trnR gene, which encodes tRNAArg, raising the possibility that AS5 destabilizes 5S rRNA or its precursor and/or blocks rRNA maturation. To investigate this, we used an in vitro system that supports 5S rRNA and trnR processing. We show that AS5 inhibits 5S rRNA maturation from a 5S-trnR precursor, and shorter versions of AS5 demonstrate that inhibition requires intergenic sequences. To test whether the sense and antisense RNAs form double-stranded regions in vitro, treatment with the single-strand-specific mung bean nuclease was used. These results suggest that 5S–AS5 duplexes interfere with a sense-strand secondary structure near the endonucleolytic cleavage site downstream from the 5S rRNA coding region. We hypothesize that these duplexes are degraded by a dsRNA-specific ribonuclease in vivo, contributing to the 5S rRNA deficiency observed in rnr1.
Commentary—Identifying Social Influence: A Comment on Opinion Leadership and Social Contagion in New Product Diffusion
Authors: Aral Sinan
Published: December 2010

Isuggest five broad directions for future research on social influence and opinion leadership that could, if appropriately addressed, dramatically improve how we conceptualize and manage social contagions in a variety of domains.
Teaching thermodynamics: The challenge
Authors: Atkins Peter
Published: December 2010

I consider the challenges of sharing thermodynamic concepts with both the general public and with students, whom I regard mostly as students of chemistry. I deal with the following challenges: (1) The order of presentation: what are the issues relating to presenting thermodynamics before or after quantum theory? (2) What should we identify as the foundations of our subject? (3) How do we convey to the general public (and the starting student) the insights that we get from the Second Law? (4) How do we bridge the gap from the qualitative to the quantitative? (5) Does visualization of calculations and concepts always help or can it make matters more complicated? (6) How do we make the transition to discussions in terms of Helmholtz and Gibbs energies, and start doing chemically useful calculations? (7) How do we keep track of the seemingly overwhelmingly large number of equations that a systematic treatment of thermodynamics inevitably generates? (8) How should we introduce statistical thermodynamics and enrich our understanding of classical thermodynamics? (9) How do we extend calculations to show the fascinating and broad scope of elementary thermodynamics?
Novel paper sizing agents from renewables. Part 1: Preparation of a paper sizing agent derived from natural plant oils
Authors: Lackinger Elisabeth , Schmid Leo , Sartori Jürgen , Isogai Akira , Potthast Antje , Rosenau Thomas
Published: December 2010

Natural oils derived from linseed, rapeseed, soybean, and a special breed of sunflower were tested for the production of maleated fatty oils for paper sizing in the ene-reaction with maleic anhydride. All these maleated oils were subjected to a conventional sizing test proving their ability to hydrophobize handsheets. Natural oils having only monounsaturated fatty acid residues (oleic acid) in the triglycerides worked best by having lower product viscosity and higher yields. The optimized production procedure employs antioxidant addition, an increased maleic anhydride:triglyceride ratio of 4:1, as well as increased pressure to reduce undesired polymeric byproducts and to increase yield.
Novel paper sizing agents from renewables. Part 3: Emulsion stability and hydrolysis behavior compared to conventional sizes
Authors: Lackinger Elisabeth , Isogai Akira , Schmid Leo , Sartori Jürgen , Potthast Antje , Rosenau Thomas
Published: December 2010

The hydrolytic stability and sizing behavior of a new paper sizing agent based on renewable vegetable oils (maleated sunflower oil, high oleic: MSOHO) was compared to two conventional alkenyl succinic anhydride (ASA) specimens, a commercial sample, and a reagent-grade ASA sample. At various pH conditions as well as upon addition of Ca2+ ions, MSOHO was more stable than both ASA samples. This superior stability of MSOHO was also supported by zeta potential measurements over 1 week. Whereas for sizing of paper higher dosages of MSOHO were needed to gain certain water repellency as compared to the ASA samples, the addition of alum had a pronounced positive effect on the sizing efficiency of MSOHO. The higher stability of MSOHO made it possible to size with an MSOHO-starch emulsion that was aged for one day at room temperature, when conventional ASA-starch emulsion had long lost any sizing efficiency.
Synthesis and herbicidal activity of 5-dehydroabietyl-1,3,4-oxadiazole derivatives
Authors: Duan Wen-Gui , Li Xing-Ren , Mo Qi-Jin , Huang Jian-Xin , Cen Bo , Xu Xue-Tang , Lei Fu-Hou
Published: December 2010

To search for novel therapeutic compounds with higher activity, a series of novel dehydroabietic acid derivatives bearing 1,3,4-oxadiazole moieties were designed and synthesized. Ten title compounds 5-dehydroabietyl-2-alkyl thio-1,3,4-oxadiazoles were synthesized by the reaction of 5-dehydroabietyl-2-mercapto-1,3,4-oxadiazole with alkyl halide or substituted benzyl halide in ethanolic KOH. All the title compounds were analyzed and characterized by means of IR, UV-vis, EI-MS, 1H-NMR, 13C-NMR, and elemental analysis. The preliminary herbicidal assay showed that almost all of the compounds exhibited an excellent growth inhibition to rape (Brassica campestris) and a certain inhibition to barnyard grass (Echinochloa crusgalli L.) at a concentration of 100 μg ml-1.
Framing and Contextualizing Information Requests: Problem Formulation as Part of the Intelligence Analysis Process
Authors: Roth Emilie M. , Pfautz Jonathan D. , Mahoney Samuel M. , Powell Gerald M. , Carlson Eric C. , Guarino Sean L. , Fichtl Ted C. , Potter Scott S.
Published: December 2010

Naturalistic decision-making studies of intelligence analysis have generally focused on information search, collection, and synthesis processes, deemphasizing the initial “problem formulation” phase, in which analysts interpret and contextualize the information request to determine which information to collect. We present the results of two studies focusing on this phase. In the first study, we performed a cognitive task analysis via semistructured interviews with 22 active-duty U.S. Army intelligence analysts to uncover factors that arise in operational environments that complicate problem formulation. The factors discovered (e.g., vague and/or overly narrow intelligence requests) led to a second study probing 6 active-duty U.S. Army intelligence analysts' cognitive strategies with a “think-aloud” protocol as they interpreted and evaluated representative information requests. The study revealed that analysts actively interpret and contextualize an information request. The analysts reframed and broadened the request so that they could respond meaningfully to the underlying intent, then used contextual cues and metainformation to determine the most useful collectors and how effectively the request could be answered in the time allotted. We discuss these results and their implications for both the cognitive modeling of intelligence analysis and the development of training and decision aids for more effective framing and contextualization of information requests.
Naturalistic Heuristics for Decision Making
Authors: Keller Niklas , Cokely Edward T. , Katsikopoulos Konstantinos V. , Wegwarth Odette
Published: December 2010

Over the last 20 years, both naturalistic decision making and fast and frugal heuristics programs have radically broken with mainstream decision science, moving beyond the confines of artificial tasks and safe academic laboratories. We document commonalities of these programs and discuss ways in which a synthesis could contribute to a more relevant, precise, predictive, and effective decision science. We begin by reviewing the common roots and philosophies of the two programs, such as their respect for the capable decision maker and their acknowledgment of the importance of task ecology. We then identify four specific areas of synergetic potential, including ecological rationality and metacognition. Our review culminates in a case study of naturalistic heuristics based on a particular class of fast and frugal heuristics. These fast and frugal trees provide examples of effective, well-specified decision-making algorithms applied in a naturalistic domain: emergency medical diagnosis. By leveraging the strengths of each program, we point out some of the ways in which more sustainable progress can be fostered on issues that matter the most—for example, decisions that save and transform lives.
Apoptosis in the germ line
Authors: Aitken R John , Findlay Jock K , Hutt Karla J , Kerr Jeff B
Published: December 2010

Apoptosis is a critical process for regulating both the size and the quality of the male and female germ lines. In this review, we examine the importance of this process during embryonic development in establishing the pool of spermatogonial stem cells and primordial follicles that will ultimately define male and female fertility. We also consider the importance of apoptosis in controlling the number and quality of germ cells that eventually determine reproductive success. The biochemical details of the apoptotic process as it affects germ cells in the mature gonad still await resolution, as do the stimuli that persuade these cells to commit to a pathway that leads to cell death. Our ability to understand and ultimately control the reproductive potential of male and female mammals depends upon a deeper understanding of these fundamental processes.
Comparison of Crestal Bone Loss and Implant Stability Among the Implants Placed With Conventional Procedure and Using Osteotome Technique: A Clinical Study
Authors: Padmanabhan Thallam Veer , Gupta Rajiv Kumar
Published: December 2010

To overcome the limitations of implant placement in knife-edge ridges, Summer introduced the osteotome technique in 1994. It has been claimed that using bone condensing to prepare the implant site in soft maxillary bone avoids the risk of heat generation, and implants can be placed precisely with increased primary stability. The purpose of this clinical study was to evaluate the crestal bone loss exhibited by the bone around early nonfunctionally loaded implants placed with conventional implant placement technique and with Summer's osteotome technique and to evaluate whether the bone-compression technique provides better primary stability than the conventional technique. A total of 10 Uniti implants were placed in the maxillary anterior region of 5 patients. One implant site was prepared using the conventional technique with drills (control group A), and second site was prepared using the osteotome technique (experimental group B) and an MIS bone compression kit. Resonance frequency measurements (RFMs) were made on each implant at the time of fixture placement and on the 180th day after implant fixture placement. The peri-implant alveolar bone loss was evaluated radiographically. Differences between the alveolar crest and the implant shoulder in radiographs were obtained immediately after implant insertion and on the 180th day after implant placement. The RFMs demonstrated a significantly higher stability of implants in control group A than in experimental group B on the day of surgery (P  =  .026). However, no statistically significant difference in stability was found between both groups on 180th day after implant placement (P  =  .076). A significant difference was found in the crestal bone levels after 180 days of surgery between two groups (P  =  0) with less crestal bone loss with group A. Within the limitations of this study we concluded that the osteotome technique is good for the purpose for which it was introduced, that is, for knife-edge ridges, and it should not be considered a substitute for conventional procedures for implant placement.
iso-Kaurenoic acid from Wedelia paludosa D.C.
Authors: Batista Ronan , García Pablo A. , Castro María Ángeles , Del Corral José M. Miguel , Feliciano Arturo S. , Oliveira Alaíde B. de
Published: December 2010

A recent reinvestigation of aerial parts of Wedelia paludosa D.C. is described and reports, for the first time, the isolation of iso-kaurenoic acid from this species.
Avaliação da chuva de sementes em áreas de restinga em diferentes estágios de regeneração
Authors: Rodrigues Maurício Augusto , Paoli Adelita Aparecida Sartori , Barbosa José Marcos , Santos Junior Nelson Augusto dos
Published: December 2010

Este estudo foi desenvolvido numa área de restinga localizada no Município de São Vicente (SP). O trabalho teve como objetivo avaliar a chuva de sementes em três condições diferentes de regeneração. Para tanto, foram selecionadas as seguintes condições: Floresta Alta de restinga em estágio médio de regeneração, uma área de clareira na mesma condição citada anteriormente e uma terceira em estágio inicial de regeneração. Em cada condição foram instalados 10 coletores de sementes confeccionados com madeira e tela sombrite 80% no fundo, mantidos a uma altura de 20 cm do solo. Foram avaliadas mensalmente, pelo período de um ano, as densidades de propágulos depositados nos coletores, sendo esses propágulos identificados e categorizados com base na sua síndrome de dispersão e na sua classe sucessional. Na Área de Floresta Alta de restinga foi realizado um levantamento fitossociológico de forma a identificar quais propágulos presentes na chuva poderiam ser oriundos dessas áreas. Foi verificado que as densidades de propágulos são relativamente baixas se comparadas com outras formações de florestas pluviais atlânticas, mas compatíveis com outros estudos realizados com a mesma formação vegetal considerada neste estudo. Com relação às síndromes de dispersão e classes sucessionais, houve predominância da síndrome zoocórica e de espécies de classes sucessionais secundárias. Os resultados permitem concluir que a área apresenta boa capacidade de manutenção da sua dinâmica sucessional.
Inventário arbóreo em dois bairros paulistanos, Jardim da Saúde e Vila Vera, localizados na subprefeitura de Ipiranga
Authors: Rossetti Adriana Ines Napias , Tavares Armando Reis , Pellegrino Paulo Renato Mesquita
Published: December 2010

Foi realizado levantamento quantiqualitativo de vegetais de porte arbóreo em dois bairros paulistanos, Vila Vera e Jardim da Saúde, situados na região Sudeste de São Paulo, não distando muito entre si, porém com características de ocupação de uso do solo bastante distintas. No Jardim da Saúde, encontraram-se 1.033 exemplares de 72 espécies botânicas, cuja altura média de todas as árvores foi de 8,07 m. A Caesalpinea peltophoroides Benth. foi a espécie mais frequente, com 20,68%, seguida da Largestroemia indica L., com 7,48%. Predominavam árvores com mais de 8,50 m de altura, sendo o pior indicador de sanidade vegetal a infestação de cupins, com 8,33% do total. Apenas 23,33% tinham situações de permeabilidade do passeio suficiente, e 5,71% delas se encontravam com conduções de podas para desobstrução das redes aéreas; o rebaixamento das árvores aconteceu em 7,74% dos exemplares. Na Vila Vera havia 178 árvores pertencentes a 42 espécies botânicas, sendo a média da altura total de 6,31 m. A espécie mais abundante foi a Caesalpinea peltophoroides Benth., com 24,71%; a segunda seria a Ligustrum lucidum W.T. Aiton, com 17,24% do total. Em 42,70% das árvores, a altura foi inferior a 4,50 m, e a sanidade vegetal estava comprometida em 12,37% dos exemplares pela infestação de cupins. Somente 7,87% dos exemplares estavam em situações de permeabilidade suficiente, as conduções de poda para desobstrução de redes eram de 3,38% e as podas de rebaixamento, de 13,48%. Havia uma média de 16,85 m de afastamento entre árvores no Jardim da Saúde, enquanto na Vila Vera esse indicativo era de 38,68 m.
Avaliação da retratibilidade da madeira de sete espécies de Eucalyptus
Authors: Oliveira José Tarcísio da Silva , Tomazello Filho Mario , Fiedler Nilton César
Published: December 2010

As variações na retratibilidade no lenho das árvores são as principais causas dos defeitos de secagem, como o empenamento e fendilhamento das peças de madeira. Os tipos de madeira presentes em um tronco estão relacionados com as variações dessa importante propriedade física. Este trabalho teve como objetivo estudar a retratibilidade da madeira de sete espécies de eucaliptos. Os parâmetros de retratibilidade, bem como a sua variação na direção radial da medula em direção à periferia do tronco de sete espécies de eucaliptos, foram avaliados de acordo com a Norma brasileira. De modo geral, os resultados indicaram que as espécies de eucaliptos estudados possuíam madeira com elevada retratibilidade. À exceção das madeiras de Eucalyptus tereticornis e E. pilularis, as demais espécies estudadas apresentaram valores menores de retratibilidade na região próxima da medula.