bluuebunny/crossref_metadata_2025 huggingface dataset:
CBB staining protocol with higher sensitivity and mass spectrometric compatibility
Authors: Pink Mario , Verma Nisha , Rettenmeier Albert W. , Schmitz‐Spanke Simone
Published: February 2010

Various CBB‐based methods for staining proteins separated by 2‐D gel electrophoresis were compared with regard to sensitivity and resolution. A modified Kang's CBB staining protocol, which we have modified, includes phosphoric acid in a concentration of 8% instead of the original 2%. This proved to be the best approach. Protein amounts as low as 2 ng and ∼2300 spots in the gel can be detected by employing this protocol. The modified procedure takes less time to carry out. Moreover, this practice is more sensitive and resolves more protein spots than most protocols reported to date and is compatible with subsequent mass spectrometric analysis.
Economic determinants of default risks and their impacts on credit derivative pricing
Authors: Liao Szu‐Lang , Chang Jui‐Jane
Published: February 2010

This study constructs a credit derivative pricing model using economic fundamentals to evaluate CDX indices and quantify the relationship between credit conditions and the economic environment. Instead of selecting specific economic variables, numerous economic and financial variables have been condensed into a few explanatory factors to summarize the noisy economic system. The impacts on default intensity processes are then examined based on no‐arbitrage pricing constraints. The approximated results show that economic factors indicated credit problems even before the recent subprime mortgage crisis, and economic fundamentals strongly influenced credit conditions. Testing of out‐of‐sample data shows that credit evolution can be identified by dynamic explanatory factors. Consequently, the factor‐based pricing model can either facilitate the evaluation of default probabilities or manage default risks more effectively by quantifying the relationship between economic environment and credit conditions. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark
Scan–rescan reliability of subcortical brain volumes derived from automated segmentation
Authors: Morey Rajendra A. , Selgrade Elizabeth S. , Wagner Henry Ryan , Huettel Scott A. , Wang Lihong , McCarthy Gregory
Published: February 2010

Large‐scale longitudinal studies of regional brain volume require reliable quantification using automated segmentation and labeling. However, repeated MR scanning of the same subject, even if using the same scanner and acquisition parameters, does not result in identical images due to small changes in image orientation, changes in prescan parameters, and magnetic field instability. These differences may lead to appreciable changes in estimates of volume for different structures. This study examined scan–rescan reliability of automated segmentation algorithms for measuring several subcortical regions, using both within‐day and across‐day comparison sessions in a group of 23 normal participants. We found that the reliability of volume measures including percent volume difference, percent volume overlap (Dice's coefficient), and intraclass correlation coefficient (ICC), varied substantially across brain regions. Low reliability was observed in some structures such as the amygdala (ICC = 0.6), with higher reliability (ICC = 0.9) for other structures such as the thalamus and caudate. Patterns of reliability across regions were similar for automated segmentation with FSL/FIRST and FreeSurfer (longitudinal stream). Reliability was associated with the volume of the structure, the ratio of volume to surface area for the structure, the magnitude of the interscan interval, and the method of segmentation. Sample size estimates for detecting changes in brain volume for a range of likely effect sizes also differed by region. Thus, longitudinal research requires a careful analysis of sample size and choice of segmentation method combined with a consideration of the brain structure(s) of interest and the magnitude of the anticipated effects. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Tactile shape discrimination recruits human lateral occipital complex during early perceptual processing
Authors: Lucan Joshua N. , Foxe John J. , Gomez‐Ramirez Manuel , Sathian K. , Molholm Sophie
Published: February 2010

Neuroimaging studies investigating somatosensory‐based object recognition in humans have revealed activity in the lateral occipital complex, a cluster of regions primarily associated with visual object recognition. To date, determining whether this activity occurs during or subsequent to recognition per se, has been difficult to assess due to the low temporal resolution of the hemodynamic response. To more finely measure the timing of somatosensory object recognition processes we employed high density EEG using a modified version of a paradigm previously applied to neuroimaging experiments. Simple geometric shapes were presented to the right index finger of 10 participants while the ongoing EEG was measured time locked to the stimulus. In the condition of primary interest participants discriminated the shape of the stimulus. In the alternate condition they judged stimulus duration. Using traditional event‐related potential analysis techniques we found significantly greater amplitudes in the evoked potentials of the shape discrimination condition between 140 and 160 ms, a timeframe in which LOC mediated perceptual processes are believed to occur during visual object recognition. Scalp voltage topography and source analysis procedures indicated the lateral occipital complex as the likely source behind this effect. This finding supports a multisensory role for the lateral occipital complex during object recognition. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Involvement of MMP‐9 in peribiliary fibrosis and cholangiocarcinogenesis via Rac1‐dependent DNA damage in a hamster model
Authors: Prakobwong Suksanti , Yongvanit Puangrat , Hiraku Yusuke , Pairojkul Chawalit , Sithithaworn Paiboon , Pinlaor Porntip , Pinlaor Somchai
Published: February 2010

Peribiliary fibrosis caused by chronic infection with Opisthorchis viverrini (OV) is a risk factor of cholangiocarcinoma (CCA) in northeastern Thailand. Matrix metalloproteinases (MMPs) are enzymes capable of degrading and remodeling the extracellular matrix in the process of fibrosis and carcinogenesis. We examined MMPs expression and their role in fibrogenesis and cholangiocarcinogenesis in hamsters treated with OV and N‐nitrosodimethylamine (NDMA). We assessed the time profiles of MMPs, inducible nitric oxide synthase (iNOS), Rac1, α‐smooth muscle actin (α‐SMA) and DNA lesions (8‐nitroguanine and 8‐oxo‐7,8‐dihydro‐2′‐deoxyguanosine, 8‐oxodG) in relation to fibrosis and CCA development. Histopathology revealed OV and NDMA synergistically induced peribiliary fibrosis time‐dependently, and CCA occurred at 3 months, whereas OV or NDMA alone induced less fibrosis. Hydroxyproline levels in the liver and plasma were positively associated with the expression of collagen I and α‐SMA. MMP‐9 expression was significantly increased and correlated with the accumulation of myofibroblast, fibrosis levels and cholangiocarcinogenesis. MMP‐9 activity was correlated with iNOS, and immunocolocalization was observed in inflammed tissues, early and invasive CCA. OV and NDMA synergistically induced MMP‐9 expression in association to Rac1. In addition, Rac1 was colocalized with iNOS, and 8‐nitroguanine, in inflammed tissues and CCA. Formation of 8‐nitroguanine and 8‐oxodG increased with tumor progression. The results suggest that MMP‐9 expression is associated with the accumulation of peribiliary fibrosis in conjunction to the induction of iNOS and Rac1 that may potentiate DNA damage and cholangiocarcinogenesis.
Enrichment for STRO‐1 expression enhances the cardiovascular paracrine activity of human bone marrow‐derived mesenchymal cell populations
Authors: Psaltis P.J. , Paton S. , See F. , Arthur A. , Martin S. , Itescu S. , Worthley S.G. , Gronthos S. , Zannettino A.C.W.
Published: February 2010

The cardiovascular therapeutic potential of bone marrow mesenchymal stromal/stem cells (MSC) is largely mediated by paracrine effects. Traditional preparation of MSC has involved plastic adherence‐isolation. In contrast, prospective immunoselection aims to improve cell isolation by enriching for mesenchymal precursor cells (MPC) at higher purity. This study compared the biological characteristics and cardiovascular trophic activity of plastic adherence‐isolated MSC (PA‐MSC) and MPC prepared from the same human donors by immunoselection for stromal precursor antigen‐1 (STRO‐1). Compared to PA‐MSC, STRO‐1‐MPC displayed greater (1) clonogenicity, (2) proliferative capacity, (3) multilineage differentiation potential, and (4) mRNA expression of mesenchymal stem cell‐related transcripts. In vitro assays demonstrated that conditioned medium from STRO‐1‐MPC had greater paracrine activity than PA‐MSC, with respect to cardiac cell proliferation and migration and endothelial cell migration and tube formation. In keeping with this, STRO‐1‐MPC exhibited higher gene and protein expression of CXCL12 and HGF. Inhibition of these cytokines attenuated endothelial tube formation and cardiac cell proliferation, respectively. Paracrine responses were enhanced by using supernatant from STRO‐1Bright MPC and diminished with STRO‐1Dim conditioned medium. Together, these findings indicate that prospective isolation gives rise to mesenchymal progeny that maintain a higher proportion of immature precursor cells compared to traditional plastic adherence‐isolation. Enrichment for STRO‐1 is also accompanied by increased expression of cardiovascular‐relevant cytokines and enhanced trophic activity. Immunoselection thus provides a strategy for improving the cardiovascular reparative potential of mesenchymal cells. J. Cell. Physiol. 223: 530–540, 2010. © 2010 Wiley‐Liss, Inc.
Shock tube study of 1,3,5‐triazine dissociation and relaxation and relaxation of pyrazine
Authors: Xu Hui , Kiefer John H.
Published: February 2010

The three‐body dissociation of 1,3,5‐triazine (s‐triazine, s‐C3H3N3 → 3HCN) has been observed in incident shock waves with the laser‐schlieren technique. The experiments use 5% triazine/Kr and cover 1630–2350 K for 100–600 Torr. These experiments show dissociation rates with strong falloff and a slight but fully expected pressure dependence. The dissociation is without secondary reaction save for a possible, but rather unlikely, contribution from the isomerization HCN → HNC. Electronic structure calculations of the transition‐state properties (G3B3, HL1, Eo = 84.6 kcal/mol) are used to construct a Rice–Ramsperger–Kassel–Marcus (RRKM) model whose fit to the rate measurements suggests a 〈ΔE〉down of 1200 cm−1. However, a seemingly better fit is achieved using the barrier of 81 kcal/mol proposed by Dyakov et al. (J. Phys. Chem. A 2007, 111, 9591–9599). With this barrier k∞ (s−1) = 5.3 × 1016 exp(−86.6(kcal/mol)/RT), and the fit now accepts the more routine 〈ΔE〉down = 126(T/298)0.9. It seems the dissociation most likely occurs by a direct, one‐step, “triple” dissociation to 3HCN, although the present experiments cannot rule out a multistep process. Vibrational relaxation of the triazine was also examined in 5% and 20% mixtures with Kr over 770–1500 K for pressures between 6 and 14 Torr. Relaxation is very fast, with a slight inverse temperature dependence, Pτ rising from 100 to 200 ns‐atm over the full temperature range. Integrated gradients are in good accord with calculated total changes in density, indicating a single exponential relaxation. A separate investigation of relaxation in the related molecule pyrazine (500–1300 K, in 1% and 5% in Kr, between 13 and 66 Torr) is included. Again relaxation is rapid, but here the temperature dependence seems more normal, the relaxation times decreasing slightly with temperature. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 211–220, 2010
Morphology of Fluid Assisted Injection Molded Polycarbonate/Polyethylene Blends
Authors: Lin Kun‐Yeh , Liu Shih‐Jung
Published: February 2010

This study aims to examine the morphological development in fluid assisted injection molded high density polyethylene (HDPE)/polycarbonate (PC) blends. Samples for microscopic observation were prepared by an 80‐ton injection‐molding machine equipped with a tube cavity and with both gas and water injection units. It was observed that the shape and size of the dispersed phase depended on the position both across the part thickness and along the flow direction. Water molded parts with a smaller PC particle distribution than gas. Additionally, high fluid pressures were found to mold parts with a smaller PC particle distribution. For both gas and water assisted injection molding, small and large particles coexisted in the skin and subskin layers, indicating that both coalescence and breakup of the dispersed phase occurred in that layer.

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Use of SELDI MS to discover and identify potential biomarkers of toxicity in InnoMed PredTox: A multi‐site, multi‐compound study
Authors: Collins Ben C. , Sposny Alexandra , McCarthy Diane , Brandenburg Arnd , Woodbury Ronald , Pennington Stephen R. , Gautier Jean‐Charles , Hewitt Phillip , Gallagher William M.
Published: February 2010

A serious bottleneck in the drug development pipeline is the inability of current pre‐clinical toxicology evaluation methods to predict early on, and with good accuracy, that a drug candidate will have to be removed from development due to toxicology/safety issues. The InnoMed PredTox consortium attempted to address this issue by assessing the value of using molecular profiling techniques (proteomics, transcriptomics, and metabonomics), in combination with conventional toxicology measurements, on decision making earlier in pre‐clinical safety evaluation. In this study, we report on the SELDI‐TOF‐MS proteomics component of the InnoMed PredTox project. In this large scale, multi‐site, multi‐compound study, tissue and plasma samples from 14‐dayin vivorat experiments conducted for 16 hepato‐ and nephro‐toxicants with known toxicology endpoints (including 14 proprietary compounds and 2 reference compounds) were analyzed by SELDI‐TOF‐MS. We have identified seven plasma proteins and four liver proteins which were shown to be modulated by treatment, and correlated with histopathological evaluations and can be considered potential biomarker candidates for the given toxicology endpoints. In addition, we report on the intra‐ and inter‐site variations observed based on measurements from a reference sample, and steps that can be taken to minimize this variation.
Changing the phospholipid composition of Staphylococcus aureus causes distinct changes in membrane proteome and membrane‐sensory regulators
Authors: Sievers Susanne , M. Ernst Christoph , Geiger Tobias , Hecker Michael , Wolz Christiane , Becher Dörte , Peschel Andreas
Published: February 2010

The dynamic lipid composition of bacterial cytoplasmic membranes has a profound impact on vital bacterial fitness and susceptibility to membrane‐damaging agents, temperature, or osmotic stress. However, it has remained largely unknown how changes in lipid patterns affect the abundance and expression of membrane proteins. Using recently developed gel‐free proteomics technology, we explored the membrane proteome of the important human pathogen Staphylococcus aureus in the presence or absence of the cationic phospholipid lysyl‐phosphatidylglycerol (Lys‐PG). We were able to detect almost half of all theoretical integral membrane proteins and could reliably quantify more than 35% of them. It is worth noting that the deletion of the Lys‐PG synthase MprF did not lead to a massive alteration but a very distinct up‐ or down‐regulation of only 1.5 or 3.5% of the quantified proteins. Lys‐PG deficiency had no major impact on the abundance of lipid‐biosynthetic enzymes but significantly affected the amounts of the cell envelope stress‐sensing regulatory proteins such as SaeS and MsrR, and of the SaeS‐regulated proteins Sbi, Efb, and SaeP. These data indicate very critical interactions of membrane‐sensory proteins with phospholipids and they demonstrate the power of membrane proteomics for the characterization of bacterial physiology and pathogenicity.
Discussion on the 300 mK anomaly in YbRh2Si2
Authors: Custers J.
Published: February 2010

The specific heat coefficient of YbRh2Si2 shows a sudden strong increase, the so‐called “upturn” at $T \approx 300\;{\rm mK}$ which also manifest itself in ac susceptibility and electrical resistivity. In mono‐isotopic 174YbRh2Si2 this upturn is absent.

At first glance, this points to a nuclear contribution as origin of the anomaly. However, based on resistivity results also impurities might be held responsible for the exotic anomaly at 300 mK.
Erratum to ‘Lagrangian simulation of wind transport in the urban environment’
Authors: Wilson J. D. , Yee E. , Ek N. , d'Amours R.
Published: February 2010

The above article was originally published on Early View on 28 July 2009, and subsequently in volume 135 (issue 643): 1586–1602; DOI:10.1002/qj.452. Copyright © 2010 Royal Meteorological Society
Treatment of vector equations in deep‐atmosphere, semi‐Lagrangian models. II: Kinematic equation
Authors: Wood N. , White A. A. , Staniforth A.
Published: February 2010

The rotation matrix formalism described in Part I of this study is here applied to the deep‐atmosphere form of the vector kinematic equation and the determination of semi‐Lagrangian ‘departure points’ (locations at the current time of fluid particles that arrive at model gridpoints at the forecast time). Following a brief review of published methods for determining departure points in models that incorporate the restrictive shallow‐atmosphere approximation, a certain discrete form of the kinematic equation is used to illustrate application of the rotation matrix technique in spherical coordinates in the deep‐atmosphere case. This discrete form–referred to as ‘doubly implicit’ –involves velocities at arrival gridpoints as well as at departure points but has several advantages over alternatives that involve velocities at a point or points along the intervening trajectory. A local Cartesian transformation method for finding departure points emerges from the rotation matrix approach applied in spherical polar coordinates. In spheroidal coordinates, a local transformation method also emerges, but the relevant Cartesian origins lie along the axis of symmetry of the spheroids rather than at their common centre. Modifications for the spherical polar case under the shallow‐atmosphere approximation are obtained by a constraint method; apart from order‐unity multiplicative factors, the resulting departure‐point equations are of the form expected given the shallow‐atmosphere momentum component equations found in Part I. © Crown Copyright 2010. Published by John Wiley & Sons, Ltd.
Sacral Neuromodulation: Does It Affect the Rectoanal Angle in Patients with Fecal Incontinence?
Authors: Uludağ Ö. , Koch S. M. P. , Vliegen R. F. , Dejong C. H. C. , van Gemert W. G. , Baeten C. G. M. I.
Published: February 2010

Background

In the past decade numerous studies have been published on the successful treatment of fecal incontinence with sacral neuromodulation (SNM). The underlying mechanism of action for lower bowel motility disorders has been unclear. In the present study, the effect of SNM on the rectoanal angle in patients with fecal incontinence was investigated.

Patients and Methods

In 12 consecutive patients who qualified for SNM an X‐defecography study was performed before SNM and at 6 months after permanent implant. Three single lateral rectal views were taken: one during rest, one during squeeze, and one during Valsalva’s maneuver, after which the patient was asked to evacuate as rapidly and completely as possible during lateral fluoroscopy. At 6 months two further defecography studies were performed, one during stimulation with the pacemaker on and one with the pacemaker off.

Results

The defecography studies showed that the rectoanal angle decreased during rest, squeeze, and Valsalva’s maneuver. A slight increase in rectoanal angle was seen during defecation. However, the differences did not reach statistical significance. Sacral neuromodulation improved fecal continence significantly in all patients at 6 months. Median incontinence episodes per week decreased from 6.2 to 1.0 (P = 0.001), and incontinent days per week decreased from 3.7 to 1.0 (P = 0.001) with SNM. There were no significant changes in the median resting and squeeze anal canal pressures, 46.5 versus 49.7 mmHg and 67.1 versus 72.3 mmHg, respectively. Median stimulation amplitude at follow‐up was 2.7 V (range: 0.9–5.3 V).

Conclusions

Rectoanal angle did not decrease significantly in patients with fecal incontinence during SNM.
Management and clinical outcome of sinonasal teratocarcinosarcoma: single institution experience
Authors: Budrukkar A , Agarwal J P , Kane S , Siddha M , Laskar S Ghosh , Pai P , Murthy V , Sengar M , D'Cruz A
Published: February 2010

Purpose:

To study the outcome of patients with sinonasal teratocarcinosarcoma treated at a single institution.

Methods:

We reviewed the medical records of 22 patients with histopathologically proven sinonasal teratocarcinosarcoma diagnosed during the period 1993–2007. Treatment was completed in 16 patients.

Results:

Fourteen patients underwent surgery (six received craniofacial resection, four open surgery and four endoscopic resection); this was followed by radiation therapy with or without chemotherapy in 11 patients. Two patients received chemoradiation as the definitive treatment. At median follow up in surviving patients of 34 months (range one to 180 months), only five were controlled. Disease recurred in 11 patients, with a median time to recurrence of seven months. The two-year disease-free survival rate and the overall survival rate were 28 and 46 per cent, respectively.

Conclusion:

Sinonasal teratocarcinosarcoma appears to be an aggressive disease, with the majority of patients suffering locoregional failure. Multimodality treatment, in the form of a combination of surgery, radiation therapy and chemotherapy, appears to be the optimal approach.
The Passio Andreae and The Dream of the Rood
Authors: Hill Thomas D.
Published: February 2010

For nearly a century now, scholars have raised the question of the influence of the apocryphal Passio Andreae on The Dream of the Rood, but this suggestion has been discussed in terms of broad similarities. One striking specific parallel concerns the history of the Cross. In the accounts of the passion of Jesus in the gospels, Jesus is forced to bear the Cross from Jerusalem to Golgotha. In The Dream of the Rood, however, Jesus goes willingly to the place where the Cross (which has been used before) has already been set up. This account of the sequence of the passion corresponds exactly to the passion of Andrew in which Andrew goes willingly and of his own volition to a Cross which has been used as a gallows before. This correspondence, together with other points of similarity, suggest that The Dream of the Rood poet used some form of the Passio Andreae as a model for his narrative.
Improving Constraints on Paleo Ice Sheets in the Amundsen Sea Embayment: Amundsen Sea Embayment: Tectonic and Climatic Evolution; Granada, Spain, 9 September 2009
Authors: Larter Robert D. , Gohl Karsten , Bentley Michael J.
Published: February 2010

Geoscientists working on the Amundsen Sea Embayment (ASE) of West Antarctica met at a workshop during the First Antarctic Climate Evolution Symposium to discuss recent advances from, and future priorities for, work in this region. The ASE is the most rapidly changing sector of the West Antarctic Ice Sheet (WAIS) and contains enough ice to raise sea level by 1.2 meters. Ice sheet modeling studies suggest that this sector of the WAIS is potentially unstable.

Considerable efforts have been made through several national Antarctic programs to acquire new data on the geological structure, subglacial topography, bathymetry, and glacial history of this remote region. These data are important for establishing boundary conditions for ice sheet modeling, for providing constraints on past ice sheet changes that can be used to test models, and for putting recent changes into a longer‐term context.
Straightforward correction for the astigmatism of a Czerny–Turner spectrometer
Authors: Chrystal C. , Burrell K. H. , Pablant N. A.
Published: February 2010

We describe a simple and inexpensive method, which corrects the astigmatism of a Czerny–Turner spectrometer. Initial characterization of the astigmatism for a particular Czerny–Turner spectrometer was performed and the design of the corrective optic is described. The optic is a thin piece of glass, which is used as a one-dimensional waveguide between the light source and the spectrometer such that the sagittal and tangential focal planes are brought to the same position. This method is demonstrated to work well between 360 and 900 nm for an f/4.7 spectrometer. With appropriate materials, corrections for longer and shorter wavelengths should also be possible. When using an inexpensive glass plate, light intensity lost with this method is approximately 12%. Improved surface finish should reduce this loss.
The stress tensor in thermodynamics and statistical mechanics
Authors: Rossi G. C. , Testa M.
Published: February 2010

We prove that the stress tensor, τab, of a molecular system with arbitrary, short-range interactions can be point-wisely expressed as the functional derivative of the partition function with respect to the local deformation tensor. In this approach, the set of components of τab has a simple interpretation as the set of Lagrangian multipliers which one needs to introduce to enforce the conditions relating point particle displacements to the body local deformation tensor. The question of the possible nonuniqueness of the formula for τab is discussed.
Infrequent sporophyte production maintains a female‐biased sex ratio in the unisexual clonal moss Hylocomium splendens
Authors: Rydgren Knut , Halvorsen Rune , Cronberg Nils
Published: February 2010

1. Sex ratios in unisexual bryophytes are most often female biased, whereas male‐biased sex ratios predominate in unisexual seed plants. This ‘bryophyte paradox’, i.e. that sex ratios are biased in favour of the sex associated with the highest reproductive costs, has remained unexplained.

2. Analysis of sex‐ratio patterns via the influence of sex distribution on population growth rates (λ) has not previously been carried out for bryophytes. We used this method to model how variation in sex ratio and sporophyte frequency influences λ in the clonal bryophyte Hylocomium splendens. We obtained λ by matrix modelling of synthetic experimental populations derived from demographic field data, using a linear two‐sex model.

3. In our set of experimental populations λ varied between 1.13 and 1.27 in response to variation in sex ratio and sporophyte frequency, with the highest λ obtained for the combination of a very low sporophyte frequency and a slightly female‐biased sex ratio.

4. Our results explain the female‐biased sex ratio of H. splendens by the slightly lower survival of and production of vegetative offspring by males than by non‐sporophytic females.

5. Synthesis. According to our models, female dominance is the predicted outcome of low to moderate fertilization success and male performance intermediate between that of sporophytic and of non‐sporophytic females. Our results therefore explain how a female‐biased sex ratio can be maintained despite higher costs of reproduction in females than in males. In dioecious bryophytes, males and females must grow in close contact for fertilization to take place. Better performance of male ramets than of the female ramets they fertilize also explains how male clones can expand into female clones. A similar performance hierarchy of males and females may occur in unisexual clonal seed plants, but more efficient fertilization systems by pollination prevents the selective advantage of unfertilized females from being realized. This explains why vascular plant populations tend to be male biased. We hypothesise difference in fertilization distance range between sperm and pollen as a simple explanation why ramet level sex ratios are in general male dominated in clonal seed plants and female dominated in clonal bryophytes.
Cross‐Language Priming of Word Meaning During Second Language Sentence Comprehension
Authors: Yuan Yanli , Woltz Dan , Zheng Robert
Published: February 2010

The experiment investigated the benefit to second language (L2) sentence comprehension of priming word meanings with brief visual exposure to first language (L1) translation equivalents. Native English speakers learning Mandarin evaluated the validity of aurally presented Mandarin sentences. For selected words in half of the sentences there was synchronized visual exposure for 100 ms of English translation equivalents. This reduced response times relative to sentences without L1 word exposure, and exposure of translation equivalents for an early word in a sentence was instrumental in reducing comprehension errors. Results are discussed with respect to (a) the unique demands on working memory of L2 speech comprehension, (b) the meaning first and sentence location principles of attention allocation in L2 comprehension, and (c) the potential utility of cross‐language meaning activation to reduce the frequency of cognitive overload during L2 listening and thereby facilitate the acquisition of a broader range of L2 comprehension skills.
Diagnostic Value of Procalcitonin for Bacterial Infection in Elderly Patients in the Emergency Department
Authors: Lai Chih‐Cheng , Chen Shey‐Ying , Wang Cheng‐Yi , Wang Jen‐Yu , Su Chan‐Ping , Liao Chun‐Hsing , Tan Che‐Kim , Huang Yu‐Tsung , Lin Hen‐I. , Hsueh Po‐Ren
Published: February 2010

OBJECTIVES: To evaluate the diagnostic performance of procalcitonin (PCT) in elderly patients with bacterial infection in the emergency department (ED).

DESIGN: Prospective.

SETTING: ED of a tertiary care hospital.

PARTICIPANTS: Elderly patients with systemic inflammatory response syndrome (SIRS) enrolled from September 2004 through August 2005.

MEASUREMENTS: A serum sample for the measurement of PCT, two sets of blood cultures, and other cultures of relevant specimens from infection sites were collected in the ED. Two independent experts blinded to the PCT results classified the patients into bacterial infection and nonbacterial infection groups.

RESULTS: Of the 262 patients with SIRS enrolled, 204 were classified as having bacterial infection and 48 as having bacteremia. PCT levels were significantly higher in patients with bacteremia than in those without. The area under the receiver operating characteristic curve for identification of bacteremia according to PCT was 0.817 for the old‐old group (≥75), significantly higher than 0.639 for the young‐old group (65–74); P=.02). The diagnostic sensitivity, specificity, positive predictive value, and negative predictive value of PCT for bacteremia in patients aged 75 and older were 96.0%, 68.3%, 33.8%, and 98.8%, respectively, with a PCT cutoff value of 0.38 ng/mL.

CONCLUSION: PCT is sensitive for diagnosing bacteremia in elderly patients with SIRS at ED admission but is helpful in excluding bacteremia only in those aged 75 and older. PCT is not an independent predictor of local infections in these patients.
Gene therapy in Alzheimer’s disease – potential for disease modification
Authors: Nilsson Per , Iwata Nobuhisa , Muramatsu Shin‐ichi , Tjernberg Lars O. , Winblad Bengt , Saido Takaomi C.
Published: February 2010

Introduction

Targets and ongoing research

Potential gene therapy target candidates

Down‐regulation of AD‐associated proteins by siRNA

Concluding remarks

Alzheimer’s disease (AD) is the major cause of dementia in the elderly, leading to memory loss and cognitive decline. The mechanism underlying onset of the disease has not been fully elucidated. However, characteristic pathological manifestations include extracellular accumulation and aggregation of the amyloid β‐peptide (Aβ) into plaques and intracellular accumulation and aggregation of hyperphosphorylated tau, forming neurofibrillary tangles. Despite extensive research worldwide, no disease modifying treatment is yet available. In this review, we focus on gene therapy as a potential treatment for AD, and summarize recent work in the field, ranging from proof‐of‐concept studies in animal models to clinical trials. The multifactorial causes of AD offer a variety of possible targets for gene therapy, including two neurotrophic growth factors, nerve growth factor and brain‐derived neurotrophic factor, Aβ‐degrading enzymes, such as neprilysin, endothelin‐converting enzyme and cathepsin B, and AD associated apolipoprotein E. This review also discusses advantages and drawbacks of various rapidly developing virus‐mediated gene delivery techniques for gene therapy. Finally, approaches aiming at down‐regulating amyloid precursor protein (APP) and β‐site APP cleaving enzyme 1 levels by means of siRNA‐mediated knockdown are briefly summarized. Overall, the prospects appear hopeful that gene therapy has the potential to be a disease modifying treatment for AD.
Changes in forest understory associated withJuniperusencroachment in Oklahoma, USA
Authors: Van Els Paul , Will Rodney E. , Palmer Michael W. , Hickman Karen R.
Published: February 2010

Question:Does understory vegetation cover and richness decline along a gradient of increasingJuniperus virginianamidstory canopy cover and is that decline best correlated with litter accumulation?

Location:Cross Timbers Forest in Payne County, OK, USA.

Methods:We measured vegetation in forest gaps as well as forest areas withoutJ. virginiana, at the inner and outer edge ofJ. virginianacanopies and nearJ. virginianatrunks (200 plots) and compared vegetation differences among location to light, litter, soil and microclimate variables.

Results:Species richness (11 spp m−2to 6 spp m−2) and summer vegetation cover (53.3% to 12.7%) declined with proximity to trunks. Regression indicated that richness declines (R2=0.08) and cover (R2=0.18) were best correlated withJ. virginianalitter accumulation. Partial canonical correspondence analysis (pCCA) revealed two strong canonical axes, one related to litter/light and another to cover ofQuercusspp. versusJ. virginiana. Tree seedlings and woody vines dominated nearJ. virginiana. Forbs, graminoids andQuercusspp. seedlings were more common in areas withoutJ. virginiana.

Conclusions:IncreasingJ. virginianaand consequent litter additions alter understory biomass and composition and, through inhibitingQuercusspp. recruitment, may lead to changes in overstory composition. Decreases in herbaceous litter, which historically contributed to fuel accumulation, may have positive feedback effects on midstory encroachment by reducing the potential for prescribed burning.
Are psychosocial factors mediators of socioeconomic status and health connections?
Authors: Matthews Karen A. , Gallo Linda C. , Taylor Shelley E.
Published: February 2010

The association between socioeconomic status (SES) and physical health is robust. Yet, the psychosocial mediators of SES‐health association have been studied in relatively few investigations. In this chapter, we summarize and critique the recent literature regarding negative emotions and cognitions, psychological stress, and resources as potential pathways connecting SES and physical health. We discuss the psychosocial origins of the SES‐health links and outline how psychosocial factors may lead to persistently low SES. We conclude that psychosocial resources may play a critical mediating role, and the origins of the SES‐health connection are apparent in childhood. We offer a blueprint for future research, which we hope contributes to a better understanding of how SES gets under the skin across the life span.
Happy Balls, Unhappy Balls, and Newton's Cradle
Authors: Kagan David
Published: February 2010

The intricacies of Newton's Cradle1 are well covered in the literature2–4 going as far back as the time of Newton!5 These discussions generally center on the highly elastic collisions of metal spheres. Thanks to the invention of happy and unhappy balls,6 you can build and study the interaction of less elastic systems (see Fig. 1).
25 Years of AAPT's PhysicsBowl
Authors: Faleski Michael C.
Published: February 2010

The PhysicsBowl is a contest for high school students that was first introduced in 1985. In this article, we discuss both some of the history of the contest as well as the 25th contest occurring this year.
What your mother never told you about … physics teaching
Authors: Roudebush Deborah
Published: February 2010

When I entered high school teaching after working in industry for several years, I was sure I knew exactly what to do. I was convinced that I would be the sage on the stage and would wow the students with my clear explanations, amazing problem-solving techniques, and perfect lab instructions. I was convinced that the students would soak up the wisdom and insight that I was offering and that, if the students just followed my directions exactly, they would be able to solve new and exciting problems. Instead, I found that the students became amazingly adept at applied mathematics and understood few of the underlying physics concepts. In fact, some of my star students who headed off to become physics majors were unprepared for the thought required and changed majors within two years.
How Do Muscles Know to Grow?
Authors: Adler Elizabeth M.
Published: February 2010

A sarcolemmal fraction of the α1S subunit may act as a sensor to couple muscle activity with muscle growth.
Functional Anatomy of Incisal Biting in Aplodontia rufa and Sciuromorph Rodents – Part 2: Sciuromorphy Is Efficacious for Production of Force at the Incisors
Authors: Druzinsky Robert E.
Published: February 2010

The protrogomorph condition of the rodent masticatory apparatus is thought to be present in only one living species, the mountain beaver Aplodontia rufa. The major anatomical difference between protrogomorphs and sciuromorphs is that the relative size of one part of the masseter muscle, the anterior lateral masseter, is much greater in sciuromorphs than in protrogomorphs. The mechanics of force production at the incisors were compared in A. rufa and six sciuromorph rodents. Is the sciuroid masticatory apparatus more effective for production of forces at the incisors during biting than the primitive, protrogomorph condition? To answer this question, three measures of mechanical ability were employed and three hypotheses were tested: (1) the mechanical advantage of the adductor musculature is greater in sciuromorphs than in A. rufa; (2) the relative force produced at the incisors is greater in sciuromorphs than in A. rufa, and (3) the relative amount of force produced that can be used to drive the incisors into an object, is greater in sciuromorphs than in A. rufa. The results demonstrated that the protrogomorph, A. rufa, is not as efficient at generating bite forces at the incisors as the sciuromorphs.
TrkB is highly expressed in NSCLC and mediates BDNF-induced the activation of Pyk2 signaling and the invasion of A549 cells
Authors: Zhang Siyang , Guo Dawei , Luo Wenting , Zhang Qingfu , Zhang Ying , Li Chunyan , Lu Yao , Cui Zeshi , Qiu Xueshan
Published: February 2010

Background

Aberrant regulation in the invasion of cancer cells is closely associated with their metastatic potentials. TrkB functions as a receptor tyrosine kinase and is considered to facilitate tumor metastasis. Pyk2 is a non-receptor tyrosine kinase and integrates signals in cell invasion. However, little is known about the expression of TrkB in NSCLC and whether Pyk2 is involved in TrkB-mediated invasion of A549 cells.

Methods

The expression of TrkB was investigated in NSCLC by immunohistochemical staining. Both HBE and A549 cells were treated with BDNF. The expression of TrkB, Pyk2 and ERK phosphorylations were assessed by western blot. Besides, A549 cells were transfected with TrkB-siRNA or Pyk2-siRNA, or treated with ERK inhibitor where indicated. Transwell assay was performed to evaluate cell invasion.

Results

40 cases (66.7%) of NSCLC were found higher expression of TrkB and patients with more TrkB expression had significant metastatic lymph nodes (p = 0.028). BDNF facilitated the invasion of A549 cells and the activations of Pyk2 in Tyr402 and ERK. However, the effects of BDNF were not observed in HBE cells with lower expression of TrkB. In addition, the increased Pyk2 and ERK activities induced by BDNF were significantly inhibited by blocking TrkB expression, so was the invasion of A549 cells. Knockdown studies revealed the essential role of Pyk2 for BDNF-induced cell invasion, since the invasion of A549 cells was abolished by Pyk2-siRNA. The application of ERK inhibitor also showed the suppressed ERK phosphorylation and cell invasion.

Conclusion

These data indicated that higher expression of TrkB in NSCLC was closely correlated with lymph node metastasis, and BDNF probably via TrkB/Pyk2/ERK promoted the invasion of A549 cells.
Repair of a defect following the removal of an impacted maxillary canine by orthodontic tooth movement: a case report
Authors: Lei Wai Yip , Rabie A Bakr M , Wong Ricky WK
Published: February 2010

This case report describes a 13-year-old boy with alveolar bony defect resulted from surgical removal of impacted upper canine transposed in the anterior region. The boy had a normal occlusion with malposition of upper central and lateral incisors. The treatment objectives were to align teeth, close spaces by mesial movement of the buccal segments in the upper jaw to repair bone loss. Fixed appliance with palatal root torque was used for the mesial movements, levelling, and alignment of teeth.

Orthodontic tooth movement consisted of a sequence of root movement in a direction to increase the thickness of the labial cortical plate of bone, could ensure healthier periodontium. A healthier periodontium prior to space closure ensured repair of alveolar bony defect after surgical intervention. Orthodontic tooth movement should be added to our armamentarium for the repair of alveolar bony defect.
Zinc-mediated Alkylation and Acylation of 1,3-Dicarbonyl Compounds
Authors: Yadav J S , Reddy B V Subba , Mishra Anand Kumar
Published: February 2010

1,3-Dicarbonyl compounds undergo smooth allylation, benzylation, propargylation, and acylation with halides using metallic zinc in DMF at 60 °C to afford the corresponding allyl, benzyl, 2-propynyl, and acylated 1,3-diesters in good yields. In the case of cyclic 1,3-diketones, the corresponding enol ethers are obtained as sole products instead of C-alkylation.
Common Genes Contribute to Depressive Symptoms and Heart Rate Variability: The Twins Heart Study
Authors: Su Shaoyong , Lampert Rachel , Lee Forrester , Bremner J. Douglas , Snieder Harold , Jones Linda , Murrah Nancy V. , Goldberg Jack , Vaccarino Viola
Published: February 2010

Depression and reduced heart rate variability (HRV) are predictors of coronary artery disease (CAD), and highly correlated with each other. However, little is known to what extend this correlation can be explained by common genetic components. We examined 198 middle-aged male twins (121 monozygotic and 77 dizygotic) from the Vietnam Era Twin Registry. Current depressive symptoms were assessed using the Beck Depression Inventory-II and HRV was assessed on 24-hour electrocardiographic Holter recordings. Five frequency domain variables were used, including ultra low frequency (ULF), very low frequency (VLF), low frequency (LF), high frequency (HF) and total power (TPow). Structural equation modeling was used to estimate shared genetic effects for depressive symptoms and the HRV frequency domains. Both depressive symptoms (h2=.5) and all measurements of HRV showed high heritability (h2=.43-.63). A significant inverse correlation was found between depressive symptoms and all HRV indices except LF and HF, with the highest coefficient (r) for TPow (r = −.24,P= .01) and ULF (r = −.24,P= .01). Bivariate genetic modeling revealed significant genetic correlations between depressive symptoms and TPow (rA= −.21,P= .04), as well as ULF (rA= −.23,P= .02). Of the total covariance between depressive symptoms and these two HRV indices, over 80% was due to the same genetic factors. In conclusion, depressive symptoms are associated with decreased HRV and this association is due, in large part, to a shared genetic effect. These results suggest that a common neurobiological dysfunction links depression and autonomic dysregulation.
Differences in Anthropometric Measurements between Sudanese Newborn Twins and Singletons
Authors: Elshibly Eltahir M. , Schmalisch Gerd
Published: February 2010

Twin pregnancies are associated with disturbed fetal growth and a higher risk of low birthweight (LBW), which is one of the most important determinants of perinatal morbidity and mortality in Africa. In this study, we compare anthropometric measurements in Sudanese twins and their mothers with singletons. Methods: In 1000 Sudanese mothers with singleton births and 30 mothers with twins, maternal (weight, height, mid-arm circumference) and 11 newborn anthropometric measurements were taken within 24 hours of delivery. Maternal education and socio-economic status were additionally recorded. Results: Mothers of twins had a significantly higher body weight (p = .045) and lean body mass (p = .02) after delivery, and were from higher social classes in general (p = .014). In addition to gestational age, twins displayed a statistically significant reduction in all anthropometric data, compared to singletons, mainly in terms of birth-weight, chest and head circumference, whereas differences in triceps and subscapular skin fold thickness and ponderal index were distinctly lower. The LBW rate in twins was markedly higher than that in singletons (43.3% vs. 8.3%, p < .001). In 20 out of 30 twins (66.7%), Twin A weighed more than Twin B (difference (SD) of 443 (335) g), and in the remaining 10 cases (33.7%), the weight of Twin B was equal to or more than that of twin A (difference (SD) of 211 (240) g, p = .039). In unlike-sex pairs, the mean (SD) difference between Twins A and B in birthweight was 459 (481) g, which was distinctly higher, compared to same-sex pairs (boys, 180 (325) g and girls, 36 (413) g). Conclusions: Sudanese twins displayed significantly reduced anthropometric measurements compared to singletons, but to different degrees. Gender had a higher impact on birthweight in twins than in singletons.
Genomewide Multiple-Loci Mapping in Experimental Crosses by Iterative Adaptive Penalized Regression
Authors: Sun Wei , Ibrahim Joseph G , Zou Fei
Published: February 2010

Genomewide multiple-loci mapping can be viewed as a challenging variable selection problem where the major objective is to select genetic markers related to a trait of interest. It is challenging because the number of genetic markers is large (often much larger than the sample size) and there is often strong linkage or linkage disequilibrium between markers. In this article, we developed two methods for genomewide multiple loci mapping: the Bayesian adaptive Lasso and the iterative adaptive Lasso. Compared with eight existing methods, the proposed methods have improved variable selection performance in both simulation and real data studies. The advantages of our methods come from the assignment of adaptive weights to different genetic makers and the iterative updating of these adaptive weights. The iterative adaptive Lasso is also computationally much more efficient than the commonly used marginal regression and stepwise regression methods. Although our methods are motivated by multiple-loci mapping, they are general enough to be applied to other variable selection problems.