bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectral discrimination of breast pathologies in situusing spatial frequency domain imaging
Authors: Laughney Ashley M , Krishnaswamy Venkataramanan , Rizzo Elizabeth J , Schwab Mary C , Barth Richard J , Cuccia David J , Tromberg Bruce J , Paulsen Keith D , Pogue Brian W , Wells Wendy A
Published: August 2013

Introduction

Nationally, 25% to 50% of patients undergoing lumpectomy for local management of breast cancer require a secondary excision because of the persistence of residual tumor. Intraoperative assessment of specimen margins by frozen-section analysis is not widely adopted in breast-conserving surgery. Here, a new approach to wide-field optical imaging of breast pathology in situ was tested to determine whether the system could accurately discriminate cancer from benign tissues before routine pathological processing.

Methods

Spatial frequency domain imaging (SFDI) was used to quantify near-infrared (NIR) optical parameters at the surface of 47 lumpectomy tissue specimens. Spatial frequency and wavelength-dependent reflectance spectra were parameterized with matched simulations of light transport. Spectral images were co-registered to histopathology in adjacent, stained sections of the tissue, cut in the geometry imaged in situ. A supervised classifier and feature-selection algorithm were implemented to automate discrimination of breast pathologies and to rank the contribution of each parameter to a diagnosis.

Results

Spectral parameters distinguished all pathology subtypes with 82% accuracy and benign (fibrocystic disease, fibroadenoma) from malignant (DCIS, invasive cancer, and partially treated invasive cancer after neoadjuvant chemotherapy) pathologies with 88% accuracy, high specificity (93%), and reasonable sensitivity (79%). Although spectral absorption and scattering features were essential components of the discriminant classifier, scattering exhibited lower variance and contributed most to tissue-type separation. The scattering slope was sensitive to stromal and epithelial distributions measured with quantitative immunohistochemistry.

Conclusions

SFDI is a new quantitative imaging technique that renders a specific tissue-type diagnosis. Its combination of planar sampling and frequency-dependent depth sensing is clinically pragmatic and appropriate for breast surgical-margin assessment. This study is the first to apply SFDI to pathology discrimination in surgical breast tissues. It represents an important step toward imaging surgical specimens immediately ex vivo to reduce the high rate of secondary excisions associated with breast lumpectomy procedures.
Cytoplasmic-targeted parvalbumin blocks the proliferation of multipotent mesenchymal stromal cells in prophase
Authors: Melo Carolina Soares Barros , Arantes Faria Jerusa Araújo Quintão , Corrêa Natássia Caroline Resende , de Andrade Carolina , Carvalho Juliana Lott , Goes Alfredo M , Rodrigues Michele A , Gomes Dawidson Assis
Published: August 2013

Introduction

Multipotent mesenchymal stromal cells (MSCs) have gained considerable interest because of their potential use in the treatment of a variety of diseases and injuries. Although remarkable advancements have been made in clinical studies, substantial concerns still regard the safety of MSCs. Some evidence suggests that MSCs can spontaneously generate a population of cells with tumorigenic potential. Thus, studying the molecular mechanisms that control the proliferation of MSCs may be a necessary step toward the development of strategies for safe clinical practice. Ca2+ is a second messenger that mediates a wide range of cellular responses, including the regulation of cell proliferation, but little is known about its function in MSCs. The aim of this study was to investigate the effects of targeted Ca2+ buffering on MSCs proliferation in vitro.

Methods

Here, we used an adenoviral (Ad) vector encoding the Ca2+ chelator protein parvalbumin (PV) fused to a nuclear exclusion signal (NES) and the Discosoma red fluorescent protein (DsRed) to investigate the function of cytoplasmic Ca2+ signals on MSC proliferation. Confocal microscopy was used to demonstrate that PV-NES-DsRed was expressed in the cytoplasm. Ca2+ signaling was monitored by using Fluo-4-AM. Fluorescence-activated cell sorting (FACS) analysis of cells that were stained with propidium iodide was used as a quantitative measure of cell death. The mitotic index was assessed by immunofluorescence, and the expression of cyclins was examined with Western blot.

Results

Our results show that the Ad-PV-NES-DsRed fusion protein decreased serum-induced Ca2+ signaling and blocked the proliferation of rat adipose-derived MSCs (AT-MSCs) in prophase. FACS analysis revealed that Ad-PV-NES-DsRed did not induce cell death in AT-MSCs. Furthermore, Western blot analysis demonstrated that Ad-PV-NES-DsRed reduced extracellular signal-regulated kinase (Erk1/2) phosphorylation and cyclin B1 expression. Buffering cytosolic Ca2+ did not alter the expression of cyclins A/D1/D2/D3/E and E2.

Conclusions

Our results show that cytoplasmic Ca2+ signals are important for AT-MSCs progression beyond prophase because of their effects on Erk phosphorylation and cyclin B1 expression.
Improved wavefield reconstruction from randomized sampling via weighted one-norm minimization
Authors: Mansour Hassan , Herrmann Felix J. , Yılmaz Özgür
Published: August 2013

Missing-trace interpolation aims to recover the gaps caused by physical obstacles or deliberate subsampling to control acquisition costs in otherwise regularly sampled seismic wavefields. Although transform-domain sparsity promotion has proven to be an effective tool to solve this recovery problem, current recovery techniques do not fully utilize a priori information derived from the locations of the transform-domain coefficients, especially when curvelet domain sparsity is exploited. We use recovery by weighted one-norm minimization, which exploits correlations between the locations of significant curvelet coefficients of different partitions, e.g., shot records, common-offset gathers, or frequency slices of the acquired data. We use these correlations to define a sequence of 2D curvelet-based recovery problems that exploit 3D continuity exhibited by seismic wavefields without relying on the highly redundant 3D curvelet transform. To test the performance of our weighted algorithm, we compared recoveries from different data sorting and partitioning scenarios for a seismic line from the Gulf of Suez. These tests demonstrated that our method is superior to standard [Formula: see text] minimization in terms of antialiasing capability, reconstruction quality and computational memory requirements.
True-amplitude Kirchhoff depth migration in anisotropic media: The traveltime-based approach
Authors: Vanelle Claudia , Gajewski Dirk
Published: August 2013

True-amplitude Kirchhoff depth migration is a classic tool in seismic imaging. In addition to a focused structural image, it also provides information on the strength of the reflectors in the model, leading to estimates of the shear properties of the subsurface. This information is a key feature not only for reservoir characterization, but it is also important for detecting seismic anisotropy. If anisotropy is present, it needs to be accounted for during the migration. True-amplitude Kirchhoff depth migration is carried out in terms of a weighted diffraction stack. Expressions for suitable weight functions exist in anisotropic media. However, the conventional means of computing the weights is based on dynamic ray tracing, which has high requirements on the smoothness of the underlying model. We developed a method for the computation of the weight functions that does not require dynamic ray tracing because all necessary quantities are determined from traveltimes alone. In addition, the method led to considerable savings in computational costs. This so-called traveltime-based strategy was already introduced for isotropic media. We extended the strategy to incorporate anisotropy. For verification purposes and comparison to analytic references, we evaluated 2.5D migration examples for [Formula: see text] and [Formula: see text] reflections. Our results confirmed the high image quality and the accuracy of the reconstructed reflectivities.
Application of the CSAMT method to groundwater exploration in a metropolitan environment
Authors: Fu Changmin , Di Qingyun , An Zhiguo
Published: August 2013

Urban and suburban areas of large cities impose great challenges to geophysical surveys because of high-level ambient noise. This is particularly true for controlled source audio-frequency magnetotellurics (CSAMT) because the frequency range of the method overlaps those of many civil and industrial noises. Among the different types of noise sources, perhaps the most noticeable one is the 50-Hz power grid. We have successfully applied the CSAMT method for groundwater exploration in a suburban Beijing area where the ambient noise level is about three times as high as would normally be encountered. Several steps were taken in assuring quality use of the method, including careful survey design, adequate frequency range selection, and large transmitter dipole length and transmitter-receiver spacing. The next step was static effect removal through low-pass filtering and topography correction to remove any nonhorizontal component in the electric field measurement. Finally, a 1D inversion method was applied to construct an (apparent) resistivity cross section. The survey revealed a low-resistivity, water-bearing layer sandwiched between a surface cover layer and the bedrock. The available well data suggested that the depth of the bedrock was accurately mapped, to within about 2 m, at a depth level of 150–165 m.
Effect of noise in blending and deblending
Authors: Berkhout Guus , Blacquière Gerrit
Published: August 2013

If simultaneous shooting is carried out by incoherent source arrays, being the condition of blended acquisition, the deblending process generates shot records with a very low residual interference (blending noise). We found, theoretically and numerically, that deblended shot records had a better background-related signal-to-noise ratio than shot records in unblended surveys. This improvement increased with increasing blending fold and decreasing survey time. An interesting consequence of this property is that blended surveys can be carried out under more severe noise conditions than unblended surveys. It is advisable to optimize the survey time in areas with a large background noise level or in areas with severe environmental restrictions.
Impact of a 2-year multimodal intervention for disruptive 6-year-olds on substance use in adolescence: randomised controlled trial
Authors: Castellanos-Ryan Natalie , Séguin Jean R. , Vitaro Frank , Parent Sophie , Tremblay Richard E.
Published: August 2013

Background

Adolescent substance use is associated with both earlier childhood behavioural problems and serious lifetime addiction problems later in life.

Aims

To examine whether, and through which mechanisms, targeting risk factors in early childhood prevents substance use across adolescence.

Method

Disruptive kindergarten boys (n = 172) living in Montreal were randomly allocated to a preventive intervention and a control condition. The intervention was delivered over 2 years (7–9 years of age) with two main components: (a) social and problem-solving skills training for the boys; and (b) training for parents on effective child-rearing skills.

Results

Adolescent substance use, up to 8 years post-intervention, was reduced in those who received the intervention (d = 0.48−0.70). Of most interest, the intervention effects were explained partly by reductions in impulsivity, antisocial behaviour and affiliation with less deviant peers during pre-adolescence (11–13 years).

Conclusions

Adolescent substance use may be indirectly prevented by selectively targeting childhood risk factors that disrupt the developmental cascade of adolescent risk factors for substance use.
Transmembrane protein 88: a Wnt regulatory protein that specifies cardiomyocyte development
Authors: Palpant Nathan J. , Pabon Lil , Rabinowitz Jeremy S. , Hadland Brandon K. , Stoick-Cooper Cristi L. , Paige Sharon L. , Bernstein Irwin D. , Moon Randall T. , Murry Charles E.
Published: August 2013

Genetic regulation of the cell fate transition from lateral plate mesoderm to the specification of cardiomyocytes requires suppression of Wnt/β-catenin signaling, but the mechanism for this is not well understood. By analyzing gene expression and chromatin dynamics during directed differentiation of human embryonic stem cells (hESCs), we identified a suppressor of Wnt/β-catenin signaling, transmembrane protein 88 (TMEM88), as a potential regulator of cardiovascular progenitor cell (CVP) specification. During the transition from mesoderm to the CVP, TMEM88 has a chromatin signature of genes that mediate cell fate decisions, and its expression is highly upregulated in advance of key cardiac transcription factors in vitro and in vivo. In early zebrafish embryos, tmem88a is expressed broadly in the lateral plate mesoderm, including the bilateral heart fields. Short hairpin RNA targeting of TMEM88 during hESC cardiac differentiation increases Wnt/β-catenin signaling, confirming its role as a suppressor of this pathway. TMEM88 knockdown has no effect on NKX2.5 or GATA4 expression, but 80% of genes most highly induced during CVP development have reduced expression, suggesting adoption of a new cell fate. In support of this, analysis of later stage cell differentiation showed that TMEM88 knockdown inhibits cardiomyocyte differentiation and promotes endothelial differentiation. Taken together, TMEM88 is crucial for heart development and acts downstream of GATA factors in the pre-cardiac mesoderm to specify lineage commitment of cardiomyocyte development through inhibition of Wnt/β-catenin signaling.
Dynamic analysis of Arabidopsis AP2 σ subunit reveals a key role in clathrin-mediated endocytosis and plant development
Authors: Fan Lusheng , Hao Huaiqing , Xue Yiqun , Zhang Liang , Song Kai , Ding Zhaojun , Botella Miguel A. , Wang Haiyang , Lin Jinxing
Published: August 2013

Clathrin-mediated endocytosis, which depends on the AP2 complex, plays an essential role in many cellular and developmental processes in mammalian cells. However, the function of the AP2 complex in plants remains largely unexplored. Here, we show in Arabidopsis that the AP2 σ subunit mutant (ap2 σ) displays various developmental defects that are similar to those of mutants defective in auxin transport and/or signaling, including single, trumpet-shaped and triple cotyledons, impaired vascular pattern, reduced vegetative growth, defective silique development and drastically reduced fertility. We demonstrate that AP2 σ is closely associated and physically interacts with the clathrin light chain (CLC) in vivo using fluorescence cross-correlation spectroscopy (FCCS), protein proximity analyses and co-immunoprecipitation assays. Using variable-angle total internal reflection fluorescence microscopy (VA-TIRFM), we show that AP2 σ-mCherry spots colocalize with CLC-EGFP at the plasma membrane, and that AP2 σ-mCherry fluorescence appears and disappears before CLC-EGFP fluorescence. The density and turnover rate of the CLC-EGFP spots are significantly reduced in the ap2 σ mutant. The internalization and recycling of the endocytic tracer FM4-64 and the auxin efflux carrier protein PIN1 are also significantly reduced in the ap2 σ mutant. Further, the polar localization of PIN1-GFP is significantly disrupted during embryogenesis in the ap2 σ mutant. Taken together, our results support an essential role of AP2 σ in the assembly of a functional AP2 complex in plants, which is required for clathrin-mediated endocytosis, polar auxin transport and plant growth regulation.
Localized Fgf10 expression is not required for lung branching morphogenesis but prevents differentiation of epithelial progenitors
Authors: Volckaert Thomas , Campbell Alice , Dill Erik , Li Changgong , Minoo Parviz , De Langhe Stijn
Published: August 2013

Localized Fgf10 expression in the distal mesenchyme adjacent to sites of lung bud formation has long been thought to drive stereotypic branching morphogenesis even though isolated lung epithelium branches in the presence of non-directional exogenous Fgf10 in Matrigel. Here, we show that lung agenesis in Fgf10 knockout mice can be rescued by ubiquitous overexpression of Fgf10, indicating that precisely localized Fgf10 expression is not required for lung branching morphogenesis in vivo. Fgf10 expression in the mesenchyme itself is regulated by Wnt signaling. Nevertheless, we found that during lung initiation simultaneous overexpression of Fgf10 is not sufficient to rescue the absence of primary lung field specification in embryos overexpressing Dkk1, a secreted inhibitor of Wnt signaling. However, after lung initiation, simultaneous overexpression of Fgf10 in lungs overexpressing Dkk1 is able to rescue defects in branching and proximal-distal differentiation. We also show that Fgf10 prevents the differentiation of distal epithelial progenitors into Sox2-expressing airway epithelial cells in part by activating epithelial β-catenin signaling, which negatively regulates Sox2 expression. As such, these findings support a model in which the main function of Fgf10 during lung development is to regulate proximal-distal differentiation. As the lung buds grow out, proximal epithelial cells become further and further displaced from the distal source of Fgf10 and differentiate into bronchial epithelial cells. Interestingly, our data presented here show that once epithelial cells are committed to the Sox2-positive airway epithelial cell fate, Fgf10 prevents ciliated cell differentiation and promotes basal cell differentiation.
Sex-specific divergence for adaptations to dehydration stress in Drosophila kikkawai
Authors: Parkash Ravi , Ranga Poonam
Published: August 2013

Several studies on diverse Drosophila species have reported higher desiccation resistance of females, but the physiological basis of such sex-specific differences has received less attention. We tested whether sex-specific differences in cuticular traits (melanic females and non-melanic males) of Drosophila kikkawai correspond with divergence in their water balance mechanisms. Our results are interesting in several respects. First, positive clinal variation in desiccation resistance was correlated with cuticular melanisation in females but with changes in cuticular lipid mass in males, despite a lack of differences between the sexes for the rate of water loss. Second, a comparative analysis of water budget showed that females of the northern population stored more body water as well as hemolymph content and exhibited greater dehydration tolerance than flies from the southern tropics. In contrast, we found no geographical variation in the males for water content and dehydration tolerance. Third, an ~10-fold increase in the rate of water loss after organic solvent treatment of male D. kikkawai suggested a role of cuticular lipids in cuticular transpiration, but had no effect in the females. Fourth, geographical differences in the storage of carbohydrate content (metabolic fuel) were observed in females but not in males. Interestingly, in females, the rate of utilization of carbohydrates did not vary geographically, but males from drier localities showed a 50% reduction compared with wetter localities. Thus, body melanisation, increased body water, hemolymph, carbohydrate content and greater dehydration tolerance confer greater desiccation resistance in females, but a reduced rate of water loss is the only possible mechanism to cope with drought stress in males. Finally, acclimated females showed a significant increase in drought resistance associated with higher trehalose content as well as dehydration tolerance, while males showed no acclimation response. Thus, sex-specific differences in desiccation resistance of D. kikkawai are associated with divergence in some water balance strategies, despite a lack of differences in the rate of water loss between the two sexes.
Thin Films of PEDOT/PSS Bar-coated on Transparent Plastic Substrates
Authors: Yan Hu , Yumoto Tatsunori , Cheng Wen-zhen , Zhang Ping , Mei Yin-ang , Zhang Ke , Okuzaki Hidenori
Published: August 2013

We have investigated highly conductive and transparent thin films of poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS) bar-coated on transparent plastic substrates such as polycarbonate (PC) and poly(ethylene terephthalate) (PET) sheets, in terms of sheet resistance (Rs), transparency (T), and surface roughness (Ra). Plasma treatment of the substrate and the addition of a surfactant and diethyl glycol (DEG) in the centrifuge-treated PEDOT/PSS dispersion are optimum coating conditions to obtain high-performance transparent PEDOT/PSS/PET sheets whose sheet resistance (Rs), transmittance at 550 nm (T), and surface roughness (Ra) were 383 Ω/sq, 75%, and 1.8 nm, respectively.
Why Hasn't Democracy Slowed Rising Inequality?
Authors: Bonica Adam , McCarty Nolan , Poole Keith T , Rosenthal Howard
Published: August 2013

During the past two generations, democratic forms have coexisted with massive increases in economic inequality in the United States and many other advanced democracies. Moreover, these new inequalities have primarily benefited the top 1 percent and even the top .01 percent. These groups seem sufficiently small that economic inequality could be held in check by political equality in the form of “one person, one vote.” In this paper, we explore five possible reasons why the US political system has failed to counterbalance rising inequality. First, both Republicans and many Democrats have experienced an ideological shift toward acceptance of a form of free market capitalism that offers less support for government provision of transfers, lower marginal tax rates for those with high incomes, and deregulation of a number of industries. Second, immigration and low turnout of the poor have combined to make the distribution of voters more weighted to high incomes than is the distribution of households. Third, rising real income and wealth has made a larger fraction of the population less attracted to turning to government for social insurance. Fourth, the rich have been able to use their resources to influence electoral, legislative, and regulatory processes through campaign contributions, lobbying, and revolving door employment of politicians and bureaucrats. Fifth, the political process is distorted by institutions that reduce the accountability of elected officials to the majority and hampered by institutions that combine with political polarization to create policy gridlock.
Downward Nominal Wage Rigidity and the Case for Temporary Inflation in the Eurozone
Authors: Schmitt-Grohé Stephanie , Uribe Martín
Published: August 2013

Since the onset of the Great Recession in peripheral Europe, nominal hourly wages have not fallen from the high levels they had reached during the boom years—this in spite of widespread increases in unemployment. This observation evokes a well-known narrative in which nominal downward wage rigidity is at the center of the current unemployment problem. We embed downward nominal wage rigidity into a small open economy with tradable and nontradable goods and a fixed exchange-rate regime. In this model, negative external shocks cause involuntary unemployment. We analyze a number of national and supranational policy options for alleviating the unemployment problem caused by the combination of downward nominal wage rigidity and a fixed exchange-rate regime. We argue that, in spite of the existence of a battery of domestic policies that could be effective in solving the unemployment problem, it is unlikely that a solution will come from within national borders. This leaves supranational monetary stimulus as the most compelling avenue out of the crisis. Our model predicts that full employment in peripheral Europe could be restored by raising the euro area annual rate of inflation to about 4 percent for the next five years.
It's the Market: The Broad-Based Rise in the Return to Top Talent
Authors: Kaplan Steven N , Rauh Joshua
Published: August 2013

One explanation that has been proposed for rising inequality is that technical change allows highly talented individuals, or “superstars” to manage or perform on a larger scale, applying their talent to greater pools of resources and reaching larger numbers of people, thus becoming more productive and higher paid. Others argue that managerial power has increased in a way that allows those at the top to receive higher pay, that social norms against higher pay levels have broken down, or that tax policy affects the distribution of surpluses between employers and employees. We offer evidence bearing on the different theories explaining the rise in inequality in the United States over recent decades. First we look the increase in pay at the highest income levels across occupations. We consider the income share of the top 1 percent over time. And we turn to evidence on inequality of wealth at the top. In looking at the wealthiest Americans, we find that those in the Forbes 400 are less likely to have inherited their wealth or to have grown up wealthy. The Forbes 400 of today also are those who were able to access education while young and apply their skills to the most scalable industries: technology, finance, and mass retail. We believe that the US evidence on income and wealth shares for the top 1 percent is most consistent with a “superstar”-style explanation rooted in the importance of scale and skill-biased technological change. It is less consistent with an argument that the gains to the top 1 percent are rooted in greater managerial power or changes in social norms about what managers should earn.
The Pay of Corporate Executives and Financial Professionals as Evidence of Rents in Top 1 Percent Incomes
Authors: Bivens Josh , Mishel Lawrence
Published: August 2013

The debate over the extent and causes of rising inequality of American incomes and wages has now raged for at least two decades. In this paper, we will make four arguments. First, the increase in the incomes and wages of the top 1 percent over the last three decades should be interpreted as driven largely by the creation and/or redistribution of economic rents, and not simply as the outcome of well-functioning competitive markets rewarding skills or productivity based on marginal differences. This rise in rents accruing to the top 1 percent could be the result of increased opportunities for rentshifting, increased incentives for rent-shifting, or a combination of both. Second, this rise in incomes at the very top has been the primary impediment to having growth in living standards for low- and moderate-income households approach the growth rate of economy-wide productivity. Third, because this rise in top incomes is largely driven by rents, there is the potential for checking (or even reversing) this rise through policy measures with little to no adverse impact on overall economic growth. Lastly, this analysis suggests two complementary approaches for policymakers wishing to reverse the rise in the top 1 percent's share of income: dismantling the institutional sources of their increased ability to channel rents their way and/or reducing the return to this rent-seeking by significantly increasing marginal rates of taxation on high incomes.
Income Inequality, Equality of Opportunity, and Intergenerational Mobility
Authors: Corak Miles
Published: August 2013

My focus is on the degree to which increasing inequality in the high-income countries, particularly in the United States, is likely to limit economic mobility for the next generation of young adults. I discuss the underlying drivers of opportunity that generate the relationship between inequality and intergenerational mobility. The goal is to explain why America differs from other countries, how intergenerational mobility will change in an era of higher inequality, and how the process is different for the top 1 percent. I begin by presenting evidence that countries with more inequality at one point in time also experience less earnings mobility across the generations, a relationship that has been called “The Great Gatsby Curve.” The interaction between families, labor markets, and public policies all structure a child's opportunities and determine the extent to which adult earnings are related to family background—but they do so in different ways across national contexts. Both cross-country comparisons and the underlying trends suggest that these drivers are all configured most likely to lower, or at least not raise, the degree of intergenerational earnings mobility for the next generation of Americans coming of age in a more polarized labor market. This trend will likely continue unless there are changes in public policy that promote the human capital of children in a way that offers relatively greater benefits to the relatively disadvantaged.
Exact Sampling of Jump Diffusions
Authors: Giesecke Kay , Smelov Dmitry
Published: August 2013

This paper develops a method for the exact simulation of a skeleton, a hitting time, and other functionals of a one-dimensional jump diffusion with state-dependent drift, volatility, jump intensity, and jump size. The method requires the drift function to be C1, the volatility function to be C2, and the jump intensity function to be locally bounded. No further structure is imposed on these functions. The method leads to unbiased simulation estimators of security prices, transition densities, hitting probabilities, and other quantities. Numerical results illustrate its features.
Scenario: Mapping Disinfection
Authors: Olds Laura , Stevens Tracey Dawn , Olds Laura , Stevens Traqcey Dawn
Published: August 2013

Scenario

St Agnes Dental Practice is a busy, four surgery NHS practice in Cornwall. With significant design modifications, the team were able to install a ‘single’ decontamination unit, and have been working to HTM 01-05 Best Practice guidelines since its completion in March 2012.
An Assessment of the Perceived Benefits and Challenges of Participating in a Practice-Based Research Network
Authors: Curro FA , Thompson VP , Grill A , Craig RG , Botello-Harbaum MB , Matthews AG , Collie D
Published: August 2013

Background

A survey was conducted to describe the benefits of and challenges to practitioner participation in the Practitioners Engaged in Applied Research and Learning (PEARL) Network, a dental practice-based research network (PBRN). The results were compared with results from medical PBRNs across different tiers of participation (based on practitioner-investigators previous involvement with PEARL research protocols).

Methods

A 39-item web-based survey addressed the benefits of PBRN participation on three levels: individual/practitioner, practice (office), and community/professional. Participants were also asked to rate challenges to participation.

Results

A total of 153 of 216 PEARL practitioner-investigators participated, a response rate of 71%. The majority (70%) was male, with a median of 23 years in private practice. ‘Means to stay informed of new developments in my profession’ was considered a ‘very important’ benefit for nearly three-quarters of the sample (71%). ‘Opportunity to improve clinical procedures’ was considered as ‘very important’ by 73% of respondents. In terms of benefits related to the community and profession, 65% of respondents reported ‘means to directly contribute to the evidence base of dental practice’ as being ‘very important’. ‘Disruption in practice routine/clinical practice’ was considered the most important challenge to participation.

Conclusions

The benefits of and challenges to participation identified did not differ across tiers of participation and were similar to benefits identified by participants in medical PBRNs. The results of this study will help facilitate the design of future PBRN protocols to encourage greater participation by the profession. Results suggest that practitioners with similar interests could be recruited to collaborative studies between medicine and dentistry.
Editorial
Authors: Coxon Mhari
Published: August 2013

The next issue of the Primary Dental Journal will focus on radiology and radiation protection. As a professional development journal for the whole dental team, we are keen to include all members of the dental profession, and are aware that this topic may not be as valuable for dental technicians. As a result, we would particularly like to hear from dental technicians who would be interested in contributing a piece for the January 2013 edition of the PDJ on dental materials. To get involved, please contact Justine Wallis at jwallis@rcseng.ac.uk
Cone-Beam Computed Tomography: Time for an Evidence-Based Approach
Authors: Horner Keith
Published: August 2013

Cone-beam computed tomography (CBCT) is an imaging technology that has revolutionised dental imaging in the last decade. Although of particular value to specialists performing implant treatment, it is increasingly being adopted by general dental practitioners. As the radiation dose is higher than that of conventional radiography, it is important to consider its diagnostic efficacy for the common tasks performed in general dental practice, such as caries diagnosis, endodontics and the detection of periapical pathosis. Any new imaging technique needs to have proven advantages over existing techniques before it is adopted, yet the evidence remains quite limited. Furthermore, image quality and radiation doses vary enormously between different manufacturers’ equipment, so that extrapolating results of one piece of research from one CBCT machine to another is fraught with pitfalls. Radiation doses with CBCT are typically an order of magnitude higher than conventional radiography. There is scope, however, for reducing these doses by judicious adjustment of exposure factors and limiting the field of view to the smallest dimensions consistent with the clinical situation. There is still a long way to go before we understand the value of CBCT in dentistry. High quality research evidence is needed, particularly with regard to assessing whether using CBCT improves patient outcomes.
Taking Radiography as an Extended Duty - A Hygienist's Perspective
Authors: Smith Emma
Published: August 2013

AS THE CONCEPT OF THE DENTAL TEAM HAS DEVELOPED, THE ROLES OF DENTAL CARE PROFESSIONALS HAVE ALSO CHANGED…
Steroid hormones and the stroma-vascular cells of the adipose tissue
Authors: Volat Fanny , Bouloumié Anne
Published: August 2013

The stroma-vascular fraction (SVF) of adipose tissue (AT) is a heterogeneous cell fraction composed of progenitor cells, endothelial cells, and immune cells. SVF plays a key role in AT homeostasis and growth as well as in obesity-associated pathologies. The SVF cell composition and phenotype are distinct according to AT location and adiposity. Such discrepancies influence AT function and are involved in obesity-associated disorders such as chronic inflammation. Investigations performed in recent years in rodents and humans provided evidence that the stroma-vascular cells contribute to the conversion of steroid hormones in AT and are also steroid targets. This review describes the link between steroids and SVF depending on gender, adiposity, and AT location and highlights the potential role of sex and corticosteroid hormones in adipogenesis, angiogenesis, and their contributions in AT inflammation.
Kinetic Study of Light Mercaptans in the Presence of Merox Catalyst and Caustic Soda
Authors: Ehsani Mohammad Reza , Mirjani Peyman , Safadoost Alireza
Published: August 2013

Due to the disgusting smell of light mercaptans, researchers are not interested in working with them, so there is not enough information available on their kinetics. This work presents kinetic investigation of oxidation of ethyl, normal-propyl, iso-propyl, and iso-butyl mercaptans in the presence of Merox catalyst. The results demonstrated that the oxidation rates of all mercaptans were first-order reaction with respect to mercaptan concentration, and the increase in NaOH concentration reduced the oxidation rate. While it was observed that there was a similarity between oxidation pattern of iso-propyl and ethyl mercaptans, another similarity was discovered between normal-propyl and iso-butyl mercaptans.
Double exposure to intra-amniotic lipopolysaccharide and maternal betamethasone induces sustained increase of neutrophils in the lungs and disrupts alveolarization in newborn rats
Authors: Lee Hyun Ju , Lee Youn Jin , Jo Heui Seung , Choi Chang Won , Kim Ee-Kyung , Kim Han-Suk , Kim Beyong Il , Choi Jung-Hwan
Published: August 2013

Aim: We investigated the combined effects of intra-amniotic lipopolysaccharide (LPS) and maternal betamethasone (BMZ) on alveolarization using a newborn rat model.

Methods: LPS (1.0 μg/sac) or vehicle was injected into the amniotic sacs of pregnant rats and BMZ (170 μg/kg) or vehicle was injected intramuscularly into the pregnant rats twice at 8-h intervals on gestation day 20. The rat pups were delivered spontaneously after 2–2.5 days and raised until the measurements were taken. Bronchoalveolar lavage was performed on days 2 and 5, and morphometric analyses of the lungs were performed on days 5 and 14.

Results: Intra-amniotic LPS significantly increased the neutrophils in the bronchoalveolar lavage fluid (BALF) on day 2, but double exposure to LPS and BMZ significantly alleviated the neutrophil increase in the BALF. On day 5, while the neutrophils in the BALF decreased in the animals exposed to LPS alone, the neutrophil numbers in the BALF were steady in the animals exposed to both LPS and BMZ. Morphometric analyses on days 5 and 14 revealed a significant disruption of alveolarization only in the animals exposed to both LPS and BMZ.

Conclusions: Our results suggested that double exposure to maternal BMZ and intra-amniotic LPS induces sustained increase of neutrophils in the lungs and disrupts alveolarization.
Reflectance confocal microscopy: A new tool in skin oncology
Authors: Meschieri Andrea , Pupelli Gaia , Pellacani Giovanni , Rajadhyaksha Milind , Longo Caterina
Published: August 2013

Nowadays in the contest of skin diseases the most important goals are the decrease of mortality through an early diagnosis and the reduction of unnecessary excisions of benign entities. Reflectance confocal microscopy (RCM) is a modern imaging technique that has been introduced in main dermatological-referral centers and applied mostly in skin oncology. Currently, RCM may be considered very useful for accurate and early diagnosis of skin cancers (such as melanoma, basal cell carcinoma, squamous cell carcinoma), enabling a specific study of epidermal structures, dermo-epidermal junction and upper dermis. RCM, as second level diagnosis tool, is helpful in several cases, in particular for challenging lesions.
Synthesis of porous carbon nanotubes/activated carbon composite spheres and their application for vitamin B12 adsorption
Authors: Lu Yuemei , Gong Qianming , Lu Fangping , Liang Ji
Published: August 2013

In this paper, carbon nanotubes (CNTs) were added to activated carbon to enhance the mesopores. At first, different amounts of CNTs were added to phenolic resin and composite spheres were synthesized by suspension polymerization. Then, by carbonizing these spheres at 600°C followed by steam activation at 850°C for more than 90 min, we prepared highly developed porous CNTs/activated carbon composite spheres. The composite spheres were characterized by a laser particle size analyzer, scanning electron microscopy, Raman spectrum, and nitrogen adsorption-desorption isotherms. Results showed that the composite spheres had good sphericity even with high proportion of CNTs (45 wt.%). Analysis also showed that the pore size distribution of the composite spheres containing CNTs was “multi-peak”, especially with 20–100-nm pores. The improved 20–100-nm porous structures in the composite spheres can be ascribed to aggregated pores of CNT bundles. The amount of vitamin B12 adsorbed on the 45 wt.% CNT composite spheres was as high as 32.38 mg/g. The spheres could be used as adsorbents for middle-molecular-weight toxins or large molecules in hemoperfusion.
Incretin-based therapies: can we achieve glycemic control and cardioprotection?
Authors: Angeli Franca S , Shannon Richard P
Published: August 2013

Glucagon-like (GLP-1) is a peptide hormone secreted from the small intestine in response to nutrient ingestion. GLP-1 stimulates insulin secretion in a glucose-dependent manner, inhibits glucagon secretion and gastric emptying, and reduces appetite. Because of the short circulating half-life of the native GLP-1, novel GLP-1 receptor (GLP-1R) agonists and analogs and dipeptidyl peptidase 4 (DPP-4) inhibitors have been developed to facilitate clinical use. Emerging evidence indicates that GLP-1-based therapies are safe and may provide cardiovascular (CV) benefits beyond glycemic control. Preclinical and clinical studies are providing increasing evidence that GLP-1 therapies may positively affect CV function and metabolism by salutary effects on CV risk factors as well as via direct cardioprotective actions. However, the mechanisms whereby the various classes of incretin-based therapies exert CV effects may be mechanistically distinct and may not necessarily lead to similar CV outcomes. In this review, we will discuss the potential mechanisms and current understanding of CV benefits of native GLP-1, GLP-1R agonists and analogs, and of DPP-4 inhibitor therapies as a means to compare their putative CV benefits.
Rethinking Our Public Health Genetics Research Paradigm
Authors: El-Sayed Abdulrahman M. , Koenen Karestan C. , Galea Sandro
Published: August 2013

Since the sequencing of the human genome, tremendous resources have been dedicated to understanding how genetic determinants may drive the production of disease. Despite some successes, the promise of genetics research in these areas remains largely unrealized.

The focus on isolating individual (or clusters of) genes that may be associated with narrowly defined phenotypes in large part explains this discrepancy. In particular, efforts to identify genotypes associated with narrow phenotypes force the field to use study designs that capitalize on homogeneous samples to minimize the potential for competing influences or confounders, which imposes important limitations on understanding the role of genes in human health.

We argue that a population health genetics that incorporates genetics into large, multiwave, multilevel cohorts has the best potential to clarify how genes, in combination and with the environment, jointly influence population health.
Social, Behavioral, and Genetic Linkages from Adolescence Into Adulthood
Authors: Harris Kathleen Mullan , Halpern Carolyn Tucker , Hussey Jon , Whitsel Eric A. , Killeya-Jones Ley , Tabor Joyce , Elder Glen , Hewitt John , Shanahan Michael , Williams Redford , Siegler Ilene , Smolen Andrew
Published: August 2013

The influence of genetic factors on health and behavior is conditioned by social, cultural, institutional, and physical environments in which individuals live, work, and play. We encourage studies supporting multilevel integrative approaches to understanding these contributions to health, and describe the Add Health study as an exemplar.

Add Health is a large sample of US adolescents in grades 7 to 12 in 1994–1995 followed into adulthood with 4 in-home interviews and biomarker collections, including DNA. In addition to sampling multiple environments and measuring diverse social and health behavior, Add Health features a fully articulated behavioral genetic sample (3000 pairs) and ongoing genotyping of 12 000 archived samples.

We illustrate approaches to understanding health through investigation of the interplay among biological, psychosocial, and physical, contextual, or cultural experiences.
Social Regulation of Human Gene Expression: Mechanisms and Implications for Public Health
Authors: Cole Steven W.
Published: August 2013

Recent analyses have discovered broad alterations in the expression of human genes across different social environments. The emerging field of social genomics has begun to identify the types of genes sensitive to social regulation, the biological signaling pathways mediating these effects, and the genetic polymorphisms that modify their individual impact. The human genome appears to have evolved specific “social programs” to adapt molecular physiology to the changing patterns of threat and opportunity ancestrally associated with changing social conditions. In the context of the immune system, this programming now fosters many of the diseases that dominate public health. The embedding of individual genomes within a broader metagenomic network provides a framework for integrating molecular, physiologic, and social perspectives on human health.
Conceptual Shifts Needed to Understand the Dynamic Interactions of Genes, Environment, Epigenetics, Social Processes, and Behavioral Choices
Authors: Jackson Fatimah L. C. , Niculescu Mihai D. , Jackson Robert T.
Published: August 2013

Social and behavioral research in public health is often intimately tied to profound, but frequently neglected, biological influences from underlying genetic, environmental, and epigenetic events. The dynamic interplay between the life, social, and behavioral sciences often remains underappreciated and underutilized in addressing complex diseases and disorders and in developing effective remediation strategies.

Using a case-study format, we present examples as to how the inclusion of genetic, environmental, and epigenetic data can augment social and behavioral health research by expanding the parameters of such studies, adding specificity to phenotypic assessments, and providing additional internal control in comparative studies.

We highlight the important roles of gene–environment interactions and epigenetics as sources of phenotypic change and as a bridge between the life and social and behavioral sciences in the development of robust interdisciplinary analyses.
The Challenge of Causal Inference in Gene–Environment Interaction Research: Leveraging Research Designs From the Social Sciences
Authors: Fletcher Jason M. , Conley Dalton
Published: August 2013

The integration of genetics and the social sciences will lead to a more complex understanding of the articulation between social and biological processes, although the empirical difficulties inherent in this integration are large.

One key challenge is the implications of moving “outside the lab” and away from the experimental tools available for research with model organisms. Social science research methods used to examine human behavior in nonexperimental, real-world settings to date have not been fully taken advantage of during this disciplinary integration, especially in the form of gene–environment interaction research.

This article outlines and provides examples of several prominent research designs that should be used in gene–environment research and highlights a key benefit to geneticists of working with social scientists.
Defining the Environment in Gene–Environment Research: Lessons From Social Epidemiology
Authors: Boardman Jason D. , Daw Jonathan , Freese Jeremy
Published: August 2013

In this article, we make the case that social epidemiology provides a useful framework to define the environment within gene–environment (G×E) research. We describe the environment in a multilevel, multidomain, longitudinal framework that accounts for upstream processes influencing health outcomes. We then illustrate the utility of this approach by describing how intermediate levels of social organization, such as neighborhoods or schools, are key environmental components of G×E research. We discuss different models of G×E research and encourage public health researchers to consider the value of including genetic information from their study participants. We also encourage researchers interested in G×E interplay to consider the merits of the social epidemiology model when defining the environment.