bluuebunny/crossref_metadata_2025 huggingface dataset:
Dark spots on Mercury: A distinctive low‐reflectance material and its relation to hollows
Authors: Xiao Zhiyong , Strom Robert G. , Blewett David T. , Byrne Paul K. , Solomon Sean C. , Murchie Scott L. , Sprague Ann L. , Domingue Deborah L. , Helbert Jörn
Published: July 2013

Orbital images acquired by the MErcury, Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft reveal a distinctive low‐reflectance material on the surface of Mercury. Such material occurs in small, isolated, and thin surficial units. We term these features “dark spots.” Dark spots have the lowest average reflectance yet documented on the planet. In every case observed at sufficiently high resolution, dark spots feature hollows at their centers. Not all hollows, however, are surrounded by a dark spot. Dark spots have been found on low‐reflectance smooth plains, intercrater plains, heavily cratered terrain, and impact craters at almost all longitudes on Mercury, but they have not been documented on high‐reflectance smooth plains material. Dark spots are one of the youngest endogenic features on Mercury, and some postdate craters with distinctive rays. Sulfides may be the phase responsible for the low albedo of dark spot material. We propose that dark spots form during the initial stages of hollow formation, perhaps in a manner similar to intense outgassing events that feature exit velocities in excess of 100 m/s. Such outgassing could contemporaneously produce a depression that constitutes an embryonic hollow. Under this scenario, dark spot material is subsequently removed or modified by regolith gardening or other surface processes on time scales shorter than the lifetime of the central hollow.
Thermokarst and export of sediment and organic carbon in the Sheldrake River watershed, Nunavik, Canada
Authors: Jolivel Maxime , Allard Michel
Published: July 2013

A spatiotemporal computation of permafrost decay covering the period from 1957 to 2009 and validated by field investigations was made over a 76 km2river catchment straddling the tree line, in the discontinuous permafrost zone, east of Hudson Bay, in order to estimate the amounts of sediments and organic carbon released by thermokarst. Lithalsas and palsas are the dominant permafrost landforms, whereas thermokarst ponds, landslides, active layer failures, and gullies are the main features of permafrost degradation. Results show that 21% of the existing permafrost in 1957 had disappeared in 2009, resulting in a 96% growth of the thermokarst pond cover and a 46 to 217% increase of the number of active erosion landforms. An increase of stream connectivity related with the degradation of permafrost potentially allowed for an increase of sediments and carbon delivery to the main stream by a factor of 1.6. Volume of active landslides and gullies also increased by 12 to 38%, enhancing sediment and organic matter yields. Significant differences in permafrost degradation and in sediment and carbon inputs were observed along an east–west transect, from sites located at the head of the watershed near the tree line to sites located downstream close to the Hudson Bay coast. Thermokarst ponds in the forest tundra area released 2.3 times more sediments and dissolved organic carbon per unit of area in the fluvial system than in the shrub tundra area. Despite these yields by thermokarst, the Sheldrake River catchment currently does not seem to be yielding proportionally more sediments and carbon than a permafrost‐free river catchment.
GCALIGNER 1.0: An alignment program to compute a multiple sample comparison data matrix from large eco‐chemical datasets obtained by GC
Authors: Dellicour Simon , Lecocq Thomas
Published: July 2013

GCALIGNER 1.0 is a computer program designed to perform a preliminary data comparison matrix of chemical data obtained by GC without MS information. The alignment algorithm is based on the comparison between the retention times of each detected compound in a sample. In this paper, we test the GCALIGNER efficiency on three datasets of the chemical secretions of bumble bees. The algorithm performs the alignment with a low error rate (<3%). GCALIGNER 1.0 is a useful, simple and free program based on an algorithm that enables the alignment of table‐type data from GC.
Electrically enhanced liquid‐phase microextraction of three textile azo dyes from wastewater and plant samples
Authors: Nojavan Saeed , Tahmasebi Zeinab , Bidarmanesh Tina , Behdad Hamideh , Nasiri‐Aghdam Mahnaz , Mansori Sozan , Pourahadi Ahmad
Published: July 2013

An electromembrane extraction procedure coupled with HPLC and visible detection was applied for the extraction of three textile azo dyes as organic salts. The extraction parameters such as extraction time, applied voltage, pH range, and concentration of salt added were optimized. A driving force of 60 V was applied to extract the analytes through 2‐nitrophenyl octyl ether, used as the supported liquid membrane, into a neutral aqueous solution. This method required 20 min extraction time from a neutral sample solution. The proposed microextraction technique provided good linearity with correlation coefficients from 0.996 to 0.998 over a concentration range of 1.0–1000.0 ng/mL. The LODs of dyes were 0.30–0.75 ng/mL, while the reproducibility ranged from 6.7 to 12.9% (n = 6). Also, enrichment factors of 96–162 that corresponded to the recoveries ranging from 48 to 81% were achieved. Finally, the application of this new method was demonstrated on wastewater samples and some plants grown in contaminated environments. Excellent selectivity was obtained as no interfering peaks were detected.
Serial computed tomographic and positron emission tomographic properties of injection material used for vocal fold augmentation
Authors: Kwon Tack‐Kyun , Lee Ji‐Eun , Cha Won Jae , Song Chang Myeon , Sung Myung‐Whun , Kim Kwang Hyun
Published: July 2013

Objectives/Hypothesis

This study aimed to demonstrate the radiological properties of hyaluronic acid (HA) and calcium hydroxylapatite (CAHA) on serial computed tomography (CT) and positron emission tomography (PET) scan.

Study Design

Retrospective Case Series.

Method

Retrospective chart and imaging analysis of patients who underwent HA or CAHA injection laryngoplasty.

Result

Total of 243 patients who underwent more than one CT of PET after last injection laryngoplasty were included. Sixty‐eight patients received HA injection and 175 patients received CAHA injection. In all cases HA showed hypo‐density in CT and no abnormal uptake on PET. CAHA showed bright calcific density on CT scan and high uptake on PET but had disappeared with time in 18 months if injected less than 0.85 mL in amount.

Conclusion

These findings support previous clinical studies on CAHA longevity and provide proper radiological interpretation on injection materials in the vocal folds.

Level of Evidence

IV (Case series) Laryngoscope, 123:2491–2496, 2013
High‐Solids‐Content Hybrid Acrylic/CeO2 Latexes with Encapsulated Morphology Assessed by 3D‐TEM
Authors: Aguirre Miren , Paulis Maria , Leiza Jose Ramon , Guraya Teresa , Iturrondobeitia Maider , Okariz Ana , Ibarretxe Julen
Published: July 2013

Hybrid acrylic/CeO2 latexes with solids content as high as 50 wt% and CeO2 content up to 1 wt% are synthesized by a seeded semibatch emulsion polymerization process. TEM images show that CeO2 nanoparticles are randomly located within the polymer particles. The 2D trasmission electron microscopy (TEM) images are not conclusive to elucidate if CeO2 is encapsulated in the hybrid polymer particles. A TEM tomographic analysis is presented here to assess their morphology. The study shows that the latexes synthesized present an encapsulated morphology for CeO2 nanoparticles regardless of whether these are located at the center or borders of the polymer particles.

image
Volume estimates for sections of certain convex bodies
Authors: Brzezinski Patryk
Published: July 2013

This paper deals with volume estimates for hyperplane sections of the simplex and for m‐codimensional sections of powers of m‐dimensional Euclidean balls. In the first part we consider sections through the centroid of the n‐dimensional regular simplex. We state a volume formula and give a lower bound for the volume of sections through the centroid. In the second part we study the extremal volumes of m‐codimensional sections “perpendicular” to of unit balls in the space for all . We give volume formulas and use them to show that the normal vector (1, 0, …, 0) yields the minimal volume. Furthermore we give an upper bound for the ‐dimensional volumes for natural numbers . This bound is asymptotically attained for the normal vector as .
Spectrum of a linear fourth‐order differential operator and its applications
Authors: Ma Ruyun , Wang Haiyan , Elsanosi Mohammed
Published: July 2013

In this paper, we apply the disconjugacy theory and Elias's spectrum theory to study the positivity and the spectrum structure of the linear operator coupled with the clamped beam boundary conditions (1.2). We also study the positivity and the spectrum structure of the more general operator coupled with (1.2). As the applications of our results on positivity and spectrum of fourth‐order linear differential operators, we show the existence of nodal solutions for the corresponding nonlinear problems via Rabinowitz's global bifurcation theorem.
Palivizumab Prophylaxis during Nosocomial Outbreaks of Respiratory Syncytial Virus in a Neonatal Intensive Care Unit: Predicting Effectiveness with an Artificial Neural Network Model
Authors: Saadah Loai M. , Chedid Fares D. , Sohail Muhammad R. , Nazzal Yazied M. , Al Kaabi Mohammed R. , Rahmani Aiman Y.
Published: July 2013

Study Objective

To identify subgroups of premature infants who may benefit from palivizumab prophylaxis during nosocomial outbreaks of respiratory syncytial virus (RSV) infection.

Design

Retrospective analysis using an artificial intelligence model.

Setting

Level IIIB, 35‐bed, neonatal intensive care unit (NICU) at a tertiary care hospital in the United Arab Emirates.

Patients

One hundred seventy six premature infants, born at a gestational age of 22–34 weeks, and hospitalized during four RSV outbreaks that occurred between April 2005 and July 2007.

Measurements and Main Results

We collected demographic and clinical data for each patient by using a standardized form. Input data consisted of seven categoric and continuous variables each. We trained, tested, and validated artificial neural networks for three outcomes of interest: mortality, days of supplemental oxygen, and length of NICU stay after the index case was identified. We compared variable impacts and performed reassignments with live predictions to evaluate the effect of palivizumab. Of the 176 infants, 31 (17.6%) received palivizumab during the outbreaks. All neural network configurations converged within 4 seconds in less than 400 training cycles. Infants who received palivizumab required supplemental oxygen for a shorter duration compared with controls (105.2 ± 7.2 days vs 113.2 ± 10.4 days, p=0.003). This benefit was statistically significant in male infants whose birth weight was less than 0.7 kg and who had hemodynamically significant congenital heart disease. Length of NICU stay after identification of the index case and mortality were independent of palivizumab use.

Conclusion

Palivizumab may be an effective intervention during nosocomial outbreaks of RSV in a subgroup of extremely low‐birth‐weight male infants with hemodynamically significant congenital heart disease.
Illustrating risk vs benefit with the tiotropium Respimat inhaler
Authors: Cates Chris
Published: July 2013

Patient decision aids present evidence‐based estimates of the risks and benefits of a particular treatment. Here, Dr Chris Cates illustrates the benefit of tiotropium in reducing exacerbations in COPD and the increased risk of mortality associated with administration via the Respimat inhaler.
Rapid degradation of solid‐phase bound peptides by the 20S proteasome
Authors: Hovestädt Marc , Kuckelkorn Ulrike , Niewienda Agathe , Keller Christin , Goede Andrean , Ay Bernhard , Günther Stefan , Janek Katharina , Volkmer Rudolf , Holzhütter Hermann‐Georg
Published: July 2013

Proteasomes are cellular proteases involved in the degradation of numerous cellular proteins. The 20S proteasome is a cylindrical 28‐mer protein complex composed of two outer heptameric α‐rings forming the entrance for the protein substrate and two inner heptameric β‐rings carrying the catalytic sites. Numerous in vitro studies have provided evidence that the 20S proteasome may degrade peptides of various lengths and even unfolded full‐length polypeptide chains. However, a direct demonstration that the 20S proteasome may also cleave surface‐attached immobilized peptides is lacking so far. To this end, we used a model system by coupling peptides from different source proteins covalently to the surface of glass beads and applied nanoLC/MS analysis to monitor the generation of proteolytic fragments in the presence of the 20S proteasome. Detectable amounts of cleavage products occurred within a few minutes indicating a much higher cleavage rate than observed with the same substrates in solution. Our finding lends support to the idea that proteasomes may directly degrade segments of membrane‐bound proteins protruding into the aqueous phase. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.
Strontium concentrations and isotope ratios in enamel of healthy and carious teeth in southern Shaanxi, China
Authors: Li Zixia , He Maoyong , Peng Bin , Jin Zhangdong
Published: July 2013

RATIONALE

As the trace element strontium (Sr) plays a significant role in dental health, it is important to determine the Sr concentration and isotope composition (87Sr/86Sr) of teeth and whether these values are related to caries formation, age and sex.

METHODS

A total of 160 permanent teeth were collected from 7‐ to 79‐year‐old people from the southern Shaanxi area of China, including 100 healthy teeth and 60 carious teeth (men and women each accounted for half of the samples). The concentration and isotope composition of Sr elements in the dental enamel of the teeth were measured using inductively coupled plasma mass spectrometry (ICP‐MS) and thermal ionization mass spectrometry (TIMS).

RESULTS

A significantly lower Sr concentration was found in the enamel of the carious teeth than in that of the healthy teeth for individuals of varying ages and sex. The Sr concentration in human carious teeth ranged between 79.70 µg/g and 85.80 µg/g; while the Sr concentration in healthy teeth ranged between 128 µg/g and 156.77 µg/g. Our results also demonstrated that the 87Sr/86Sr ratio did not appear to be affected by the caries formation, age or sex. The 87Sr/86Sr ratio in the enamel of the healthy and carious teeth of individuals of varying ages and genders ranged between 0.710935 and 0.711037, which falls into the range of 87Sr/86Sr ratios found in the local, naturally occurring water, soils and rocks.

CONCLUSIONS

Sr plays a significant role in dental health, and there is a negative correlation between Sr and the occurrence of dental caries. The 87Sr/86Sr ratio of teeth reflects the 87Sr/86Sr ratio of the associated environment, and there is no significant relationship with the frequency of dental caries, age or sex. Copyright © 2013 John Wiley & Sons, Ltd.
Statistical comparison of TEC derived from GPS and ISR observations at high latitudes
Authors: Makarevich Roman A. , Nicolls Michael J.
Published: July 2013

A comprehensive data set collected with the Poker Flat Incoherent Scatter Radar (PFISR) and GPS receiver in Fairbanks, Alaska (magnetic latitude = 65.4°N) in 2007–2010 is employed to analyze and compare the total electron content (TEC) estimates derived from two radio techniques at high latitudes. The average TEC trends are shown to be largely similar and consistent with expectations based on solar conditions. The TEC residuals expressed as the difference and ratio between the PFISR‐ and GPS‐derived TEC are evaluated to be below 2 total electron content units (TECU = 1016 electronsm−2) and 0.7–0.8, respectively, with some dependence on solar conditions. The agreement between TEC estimates is examined by limiting the difference between the GPS satellite and PFISR beam elevations to 2.5° and postintegrating GPS measurements over the period of each PFISR measurement. Factors controlling the agreement are investigated, including possible roles of GPS satellite bias, GPS elevation angle, and topside contribution to TEC. It is demonstrated that the best agreement, expressed as a linear correlation and a fraction of points consistent with the linear trend, is achieved with satellites at the largest elevation angles and smallest distances from PFISR, which are a possible effect of small spatial differences and unremoved differential biases. Estimates of the topside contribution to TEC range between 14% and 30% and are most consistent during daytime hours, while observations near the solar terminator and during the night suffer from large uncertainties.
Passive all‐sky imaging radar in the HF regime with WWV and the first station of the Long Wavelength Array
Authors: Helmboldt J. F. , Clarke T. E. , Craig J. , Dowell J. D. , Ellingson S. W. , Hartman J. M. , Hicks B. C. , Kassim N. E. , Taylor G. B. , Wolfe C. N.
Published: July 2013

We present a new passive, bistatic high‐frequency (HF) radar system consisting of the transmitters for the radio station WWV and the dipole antenna array that comprises the first station of the Long Wavelength Array (LWA) or “LWA1.” We demonstrate that these two existing facilities, which are operated for separate purposes, can be used together as a unique HF radar imager, capable of monitoring the entire visible sky. In this paper, we describe in detail the techniques used to develop all‐sky radar capability at 10, 15, and 20 MHz. We show that this radar system can be a useful tool for probing ionospheric structure and its effect on over‐the‐horizon (OTH) geolocation. The LWA1+WWV radar system appears to be especially adept at detecting and characterizing structures associated with sporadic‐E. In addition, we also demonstrate how this system may be used for long‐distance, OTH mapping of terrain/ocean HF reflectivity. Finally, we discuss the potential improvements in the utility of these applications as more LWA stations are added.
Orchestrating osteogenic differentiation of mesenchymal stem cells—identification of placental growth factor as a mechanosensitive gene with a pro-osteogenic role
Authors: McCoy Ryan J. , Widaa Amro , Watters Karen M. , Wuerstle Maximilian , Stallings Ray L. , Duffy Garry P. , O'Brien Fergal J.
Published: July 2013

Skeletogenesis is initiated during fetal development and persists through adult life as either a remodeling process in response to homeostatic regulation or as a regenerative process in response to physical injury. Mesenchymal stem cells (MSCs) play a crucial role providing progenitor cells from which osteoblasts, bone matrix forming cells are differentiated. The mechanical environment plays an important role in regulating stem cell differentiation into osteoblasts, however, the mechanisms by which MSCs respond to mechanical stimuli are yet to be fully elucidated. To increase understanding of MSC mechanotransuction and osteogenic differentiation, this study aimed to identify novel, mechanically augmented genes and pathways with pro-osteogenic functionality. Using collagen glycoaminoglycan scaffolds as mimics of native extracellular matrix, to create a 3D environment more representative of that found in bone, MSC-seeded constructs were mechanically stimulated in a flow-perfusion bioreactor. Global gene expression profiling techniques were used to identify potential candidates warranting further investigation. Of these, placental growth factor (PGF) was selected and expression levels were shown to strongly correlate to both the magnitude and duration of mechanical stimulation. We demonstrated that PGF gene expression was modulated through an actin polymerization-mediated mechanism. The functional role of PGF in modulating MSC osteogenic differentiation was interrogated, and we showed a concentration-dependent response whereby low concentrations exhibited the strongest pro-osteogenic effect. Furthermore, pre-osteoclast migration and differentiation, as well as endothelial cell tubule formation also maintained concentration-dependent responses to PGF, suggesting a potential role for PGF in bone resorption and angiogenesis, processes key to bone remodeling and fracture repair.
Mesenchymal stem cells inhibit cutaneous radiation-induced fibrosis by suppressing chronic inflammation
Authors: Horton Jason A. , Hudak Kathryn E. , Chung Eun Joo , White Ayla O. , Scroggins Bradley T. , Burkeen Jeffrey F. , Citrin Deborah E.
Published: July 2013

Exposure to ionizing radiation (IR) can result in the development of cutaneous fibrosis, for which few therapeutic options exist. We tested the hypothesis that bone marrow-derived mesenchymal stem cells (BMSC) would favorably alter the progression of IR-induced fibrosis. We found that a systemic infusion of BMSC from syngeneic or allogeneic donors reduced skin contracture, thickening, and collagen deposition in a murine model. Transcriptional profiling with a fibrosis-targeted assay demonstrated increased expression of interleukin-10 (IL-10) and decreased expression of IL-1β in the irradiated skin of mice 14 days after receiving BMSC. Similarly, immunoassay studies demonstrated durable alteration of these and several additional inflammatory mediators. Immunohistochemical studies revealed a reduction in infiltration of proinflammatory classically activated CD80+ macrophages and increased numbers of anti-inflammatory regulatory CD163+ macrophages in irradiated skin of BMSC-treated mice. In vitro coculture experiments confirmed that BMSC induce expression of IL-10 by activated macrophages, suggesting polarization toward a regulatory phenotype. Furthermore, we demonstrated that tumor necrosis factor-receptor 2 (TNF-R2) mediates IL-10 production and transition toward a regulatory phenotype during coculture with BMSC. Taken together, these data demonstrate that systemic infusion of BMSC can durably alter the progression of radiation-induced fibrosis by altering macrophage phenotype and suppressing local inflammation in a TNF-R2-dependent fashion.
Cyclin D3 critically regulates the balance between self-renewal and differentiation in skeletal muscle stem cells
Authors: Luca Giulia , Ferretti Roberta , Bruschi Marco , Mezzaroma Eleonora , Caruso Maurizia
Published: July 2013

Satellite cells are mitotically quiescent myogenic stem cells resident beneath the basal lamina surrounding adult muscle myofibers. In response to injury, multiple extrinsic signals drive the entry of satellite cells into the cell cycle and then to proliferation, differentiation, and self-renewal of their downstream progeny. Because satellite cells must endure for a lifetime, their cell cycle activity must be carefully controlled to coordinate proliferative expansion and self-renewal with the onset of the differentiation program. In this study, we find that cyclin D3, a member of the family of mitogen-activated D-type cyclins, is critically required for proper developmental progression of myogenic progenitors. Using a cyclin D3-knockout mouse we determined that cyclin D3 deficiency leads to reduced myofiber size and impaired establishment of the satellite cell population within the adult muscle. Cyclin D3-null myogenic progenitors, studied ex vivo on isolated myofibers and in vitro, displayed impaired cell cycle progression, increased differentiation potential, and reduced self-renewal capability. Similarly, silencing of cyclin D3 in C2 myoblasts caused anticipated exit from the cell cycle and precocious onset of terminal differentiation. After induced muscle damage, cyclin D3-null myogenic progenitors exhibited proliferation deficits, a precocious ability to form newly generated myofibers and a reduced capability to repopulate the satellite cell niche at later stages of the regeneration process. These results indicate that cyclin D3 plays a cell-autonomous and nonredundant function in regulating the dynamic balance between proliferation, differentiation, and self-renewal that normally establishes an appropriate pool size of adult satellite cells.
Dysfunction of Endothelial Progenitor Cells from Smokers and Chronic Obstructive Pulmonary Disease Patients Due to Increased DNA Damage and Senescence
Authors: Paschalaki Koralia E. , Starke Richard D. , Hu Yanhua , Mercado Nicolas , Margariti Andriana , Gorgoulis Vassilis G. , Randi Anna M. , Barnes Peter J.
Published: July 2013

Cardiovascular disease (CVD) is a major cause of death in smokers, particularly in those with chronic obstructive pulmonary disease (COPD). Circulating endothelial progenitor cells (EPC) are required for endothelial homeostasis, and their dysfunction contributes to CVD. To investigate EPC dysfunction in smokers, we isolated and expanded blood outgrowth endothelial cells (BOEC) from peripheral blood samples from healthy nonsmokers, healthy smokers, and COPD patients. BOEC from smokers and COPD patients showed increased DNA double-strand breaks and senescence compared to nonsmokers. Senescence negatively correlated with the expression and activity of sirtuin-1 (SIRT1), a protein deacetylase that protects against DNA damage and cellular senescence. Inhibition of DNA damage response by silencing of ataxia telangiectasia mutated (ATM) kinase resulted in upregulation of SIRT1 expression and decreased senescence. Treatment of BOEC from COPD patients with the SIRT1 activator resveratrol or an ATM inhibitor (KU-55933) also rescued the senescent phenotype. Using an in vivo mouse model of angiogenesis, we demonstrated that senescent BOEC from COPD patients are dysfunctional, displaying impaired angiogenic ability and increased apoptosis compared to cells from healthy nonsmokers. Therefore, this study identifies epigenetic regulation of DNA damage and senescence as pathogenetic mechanisms linked to endothelial progenitors' dysfunction in smokers and COPD patients. These defects may contribute to vascular disease and cardiovascular events in smokers and could therefore constitute therapeutic targets for intervention. Stem Cells  2013;31:2813–2826
Is There an Appropriate Balance Between the Number of Solar and Space Physics PhDs and the Jobs Available?
Authors: Moldwin Mark B. , Torrence John , Moldwin Lauren A. , Morrow Cherilynn
Published: July 2013

Key Points

The first demographic survey of Solar and Space Physics (S&SP) was conducted

Annual number of PhD awarded in S&SP has doubled over the last decade

Annual number of jobs advertised in S&SP have decreased in recent years
Computational approaches for understanding energy metabolism
Authors: Shestov Alexander A. , Barker Brandon , Gu Zhenglong , Locasale Jason W.
Published: July 2013

There has been a surge of interest in understanding the regulation of metabolic networks involved in disease in recent years. Quantitative models are increasingly being used to interrogate the metabolic pathways that are contained within this complex disease biology. At the core of this effort is the mathematical modeling of central carbon metabolism involving glycolysis and the citric acid cycle (referred to as energy metabolism). Here, we discuss several approaches used to quantitatively model metabolic pathways relating to energy metabolism and discuss their formalisms, successes, and limitations. WIREs Syst Biol Med 2013, 5:733–750. doi: 10.1002/wsbm.1238

This article is categorized under:

Analytical and Computational Methods > Computational Methods

Models of Systems Properties and Processes > Mechanistic Models

Biological Mechanisms > Metabolism
Effects of elevated levels of lead in ceramics on provenancing studies using non‐destructive PXRF: a case study in Byzantine Cypriot glazed ceramics
Authors: Forster Nicola , Grave Peter
Published: July 2013

Glazed ceramics are ubiquitous in the medieval archaeological record in the Mediterranean. The effects of lead volatilisation during firing of glazed ceramics on non‐destructive PXRF (portable X‐ray fluorescence) are evaluated using 25 Byzantine Cypriot glazed ceramics. Significant spectral interferences reduce the number of discriminating elements for multivariate statistical analysis, limiting the capacity of non‐destructive PXRF to resolve compositional differences. Nonetheless, non‐destructive PXRF of glazed wares has the potential to expand provenancing studies where significantly different geology is present or for appropriate archaeological questions. Copyright © 2013 John Wiley & Sons, Ltd.
Robotic Endocrine Surgery: State of the Art
Authors: Taskin Halit Eren , Arslan Naciye Cigdem , Aliyev Shamil , Berber Eren
Published: July 2013

Over the last decade, developments in technology have led a rapid progress in robotic endocrine surgery applications. Robotics is attractive to the surgeon because of the three‐dimensional image quality, articulating instruments, and stable surgical platform. Safety and effectiveness of robotic adrenalectomy and thyroidectomy have been shown in many studies. While these robotic procedures offer better ergonomics for the surgeon, they provide similar outcomes compared to the laparoscopic approach for adrenalectomy and better cosmetic results versus the conventional option for thyroidectomy. Recently, while the robotic approach for adrenalectomy has been popularized, enthusiasm for robotic thyroidectomy has decreased. In the present review we aim to describe emerging robotic procedures and review the literature regarding outcomes.
Quality Improvement Activities for Surgical Services at District Hospitals in Developing Countries and Perceived Barriers to Quality Improvement: Findings From Ghana and the Scientific Literature
Authors: Choo Shelly , Papandria Dominic , Goldstein Seth D. , Perry Henry , Hesse Afua A. J. , Abatanga Francis , Abdullah Fizan
Published: July 2013

Background

Most quality improvement (QI) activities in developing countries, established with funds from external donors, are focused on specific diseases or outreach programs, such as family planning or child survival. District hospitals in developing countries serve as the primary entry point for patients with surgical problems in developing countries, yet little is known about the extent to which formal QI activities for surgical services are present in these settings or the perceptions of hospital staff about the barriers to improving quality in this setting. This study aimed to document surgical QI efforts at district hospitals and perceived barriers to improving quality in a developing country—Ghana. It also provides a summary of the existing published scientific literature concerning surgical QI in developing countries.

Methods

A survey team visited 10 government district hospitals in Ghana, one in each of Ghana’s 10 regions. The number and type of QI activities (surgical and nonsurgical) at these district hospitals and the perspectives of hospital staff regarding the steps required to improve the quality of surgical services in their facility were recorded.

Results

Of the 10 hospitals assessed, nine reported having some type of QI activity, ranging from satisfaction surveys to assessing quality of infection prevention. Only one hospital reported having QI activity addressing surgical care. To improve the quality of surgical care, seven hospitals reported the need for trained specialists in surgery, obstetrics, and gynecology. Six cited the need for an appropriately equipped operating theater and recovery ward. The primary barrier to achieving these recommendations, cited by 70 % of the hospitals, was the inability to recruit and retain qualified specialists with surgical skills.

Conclusions

For Ghana to improve significantly the quality of surgical care provided in its district hospitals, greater emphasis is needed for continuous, systematic QI monitoring and for solving the problems identified. Increasing the number of appropriately trained surgical care providers is essential to strengthen the quality of surgical services in district hospitals. These findings likely apply to other resource‐limited countries as well. Increased attention to improving the quality of surgical services at district hospitals in developing countries is urgently needed.
Ontogenetic timing of density dependence: location‐specific patterns reflect distribution of a limiting resource
Authors: Teichert Maxim A. K. , Einum Sigurd , Finstad Anders G. , Ugedal Ola , Forseth Torbjørn
Published: July 2013

Theoretical considerations suggest that the relative abundance of age‐specific limiting resources determines the ontogenetic timing of density dependence. Structural shelters may represent one such resource which can become increasingly scarce with increasing body size. Here we use a time series of juvenile Atlantic salmon (Salmo salar) densities and ask whether ontogenetic patterns of density‐dependent losses in two separate reaches of a river can be predicted by considering their shelter abundances. The analyses were conducted using sampling site data (n= 30) as well as stream‐reach averages. Loss rates from the egg to the young‐of‐the‐year stage were density‐dependent in both reaches. For the transition from the young‐of‐the‐year to the yearling stage, when shelters are more likely to become limiting, the results were sensitive to the spatial scale of analysis. On the reach scale, among‐year variation in loss rates was positively correlated with density in the reach with the lowest shelter abundance, whereas no such effect was found in the other reach. This demonstrates that the ontogenetic timing of density dependence can vary among areas within populations, and hence among populations, and that this variation can be explained by quantification of age‐specific limiting factors. For analyses at the sample site scale this pattern was reversed, with stronger density dependence in the reach with highest shelter abundance. However, this result was clearly driven by immigration into low density sites, which masked the true reach‐level effect. Thus, our study also exemplifies how population level regulation inferred from patch‐ or trap‐based data that fails to account for animal movements can be biased.
Cross-pollination benefits differ among oilseed rape varieties
Authors: HUDEWENZ A. , PUFAL G. , BÖGEHOLZ A-L. , KLEIN A-M.
Published: July 2013

Winter oilseed rape (Brassica napus) is an important crop for human consumption and biofuel production and its production is increasing worldwide. It is generally assumed that cross-pollination by insects increases oilseed rape yield but testing of this has been restricted to a few rapeseed varieties and produced varying results. The present study determines whether cross-pollination benefits a number of oilseed rape varieties by comparing yield in the presence and absence of insects. Four rapeseed varieties (Sherlock, Traviata, Treffer and Visby) were used with ten individuals each in four pollination treatments: (1) supplementary hand-pollination, (2) open pollination with insects able to access the flowers, (3) wind pollination and (4) autonomous self-pollination. Across all four varieties, open and supplementary hand-pollination treatments resulted in higher fruit set, numbers of seeds per pod and seed yield compared with wind and self-pollination. The cross-pollination benefits, however, differed among rapeseed varieties: Treffer and Visby had a higher dependence on open (insects) and supplementary cross-pollination than Sherlock and Traviata. Across all four varieties, seed weight compensated for reduced fruit set and was highest when plants were self-pollinated. The present results highlight the importance of considering varietal differences in crop pollination research. Information on the pollination requirements of crop varieties is required by farmers to optimize management decisions in a world of increasing agropollination deficits.
On taxing wildlife films and exposure to nature
Authors: Wunder Sven , Sheil Douglas
Published: July 2013

Some conservation finance strategies feature taxes on nature's benign, and arguably educational, uses. This applies to a recent proposal to extract payment from producers of nature films and also to past efforts to raise entrance fees to protected areas. We argue that, as they are currently formulated, it is misleading to label these proposals as payments for environmental service schemes, as they lack voluntary and conditional payments. Rather, they are a form of taxation. Such revenue-seeking measures may prove to be short-sighted. They will raise prices and curtail the demand for those environmental services that embody some element of education, thus reducing public exposure to nature. This could diminish public awareness, curb people's biophilia and devalue Nature's ‘existence values’. This drive for more conservation cash income in the short term could undermine a broad, long-term societal basis for conservation and its future financing.
Effect of plasma channel non-uniformity on resonant third harmonic generation
Authors: Panwar Anuraj , Ryu Chang-Mo , Kumar Ashok
Published: July 2013

We study the generation of resonant third harmonic laser radiation in a density non-uniform rippled plasma channel. An introduction of plasma channel non-uniformity strongly enhances the self-focusing and compression of main laser pulse at lower powers. In a deeper plasma channel, self-focusing is less sensitive to laser amplitude variation but increases compression. Plasma density ripple ‘nq’ leading to resonant third harmonic generation when kq = 4ω2p/3meω0cγ0, where ‘ω’p is electron plasma frequency, ‘ω0’ is laser frequency, and ‘γ0’ is the electron Lorentz factor. Third harmonic is produced through the beating of ponderomotive force induced second harmonic density oscillations and the oscillatory velocity of electrons at main laser frequency. The self-focusing and compression of the fundamental pulse periodically enhances the intensity of the third-harmonic pulse at lower powers of main laser. In a deeper plasma channel, the third harmonic power is less effective by self-focusing and the compression of main laser, and increase with main laser pulse power.
Evaluation of left ventricular volumes in the early neonatal period using three-dimensional echocardiography
Authors: Nagasawa Hiroyuki
Published: July 2013

Background

Awareness about normal cardiac volumes in the neonatal period is very important for understanding the cardiac function; however, the small cardiac size of neonates makes it difficult to perform invasive examinations. Three-dimensional echocardiography is used to evaluate cardiac volumes in children. However, no studies using this method have examined left ventricular volumes in neonates during the early neonatal period.

Methods

The study group consisted of 255 normal neonates. Comparisons of the stroke volume calculated according to the velocity–time integral and Pombo method were made.

Results

The volumes in both end-diastole and end-systole and the stroke volume gradually decreased over time after birth. Participants with continuous a persistent ductus arteriosus flow had higher stroke volumes than those without persistent ductus arteriosus. The average end-diastolic volume per body surface area (m2) was 30.61 ml/m2 in boys and 29.80 ml/m2 in girls, whereas the ventricular end-systolic volume was 12.89 ml/m2 in boys and 12.80 ml/m2 in girls among the participants without persistent ductus arteriosus. The average stroke volume was 17.70 ml/m2 in boys and 17.00 ml/m2 in girls. Statistically significant gender differences were observed in the end-diastolic volume (p = 0.0053), stroke volume (p < 0.0001), and ejection fraction (p = 0.039). The cardiac index was calculated to be 2.04 L/minute/m2 in boys and 1.95 L/minute/m2 in girls, which was significantly lower than that calculated using the velocity–time integral and Pombo method (p < 0.0001).

Conclusions

Significant gender differences in the end-diastolic volume, stroke volume, and ejection fraction at birth were revealed. The cardiac index in the early neonatal period was found to be relatively smaller than what had previously been recognised.
Hypertrophic cardiomyopathy: prognostic factors and survival analysis in 128 Egyptian patients
Authors: El-Saiedi Sonia A. , Seliem Zeinab S. , Esmail Reem I.
Published: July 2013

Background: Hypertrophic cardiomyopathy is an important cause of disability and death in patients of all ages. Egyptian children may differ from Western and Asian patients in the pattern of hypertrophy distribution, clinical manifestations, and risk factors. Objectives: The aim of our study was to report the clinical characteristics and outcomes of Egyptian children with hypertrophic cardiomyopathy studied over a 7-year duration and to determine whether the reported adult risk factors for sudden cardiac death are predictive of the outcome in these affected children. Study design and methods: This retrospective study included 128 hypertrophic cardiomyopathy children. The data included personal history, family history, physical examination, baseline laboratory measurements, electrocardiogram, and Holter and echocardiographic results. Logistic regression analysis was used for the detection of risk factors of death. Results: Fifty-one out of 128 patients died during the period of the study. Of the 51 deaths, 36 (70.5%) occurred in patients presenting before 1 year of age. Only eight patients had surgical intervention. Extreme left ventricular hypertrophy, that is, interventricular septal wall thickness or posterior wall thickness Z-score >6, sinus tachycardia, and supraventricular tachycardia were found to be independent risk factors for prediction of death in patients with hypertrophic cardiomyopathy. Conclusions: At our Egyptian tertiary care centre, hypertrophic cardiomyopathy has a relatively worse prognosis when compared with reports from Western and Asian series. Infants have a worse outcome than children presenting after the age of 1 year. A poorer prognosis in childhood hypertrophic cardiomyopathy is predicted by an extreme left ventricular hypertrophy, the presence of sinus tachycardia, and supraventricular tachycardia.
Insulin resistance and atherosclerosis: convergence between metabolic pathways and inflammatory nodes
Authors: Stöhr Robert , Federici Massimo
Published: July 2013

For some time now it has been known that diabetes and atherosclerosis are chronic inflammatory diseases that are closely associated with one another and often develop together. In both there is an increase in tissue-wide inflammation that is exhibited by the infiltration of immune cells into the adipose tissue and the vascular walls respectively. The monocyte/macrophage populations that are recruited in these seemingly different settings also display a high similarity by exhibiting similar phenotypes in both conditions. In the insulin resistant as well as the atherosclerotic setting there is a distinct switch in the macrophage populations present from an anti-inflammatory (M2) population to an inflammatory (M1) population, which releases cytokines and chemotactic factors with the ability to worsen the local environment and thus aggravate the situation by creating a vicious circle. However, although some discoveries suggest that preventing the development of M1 macrophages reduces inflammation and thereby aggravation of these diseases, there are currently no clear-cut opinions on how to achieve a switch from M2 to M1.
Androgen response element of the glycine N-methyltransferase gene is located in the coding region of its first exon
Authors: Lee Cheng-Ming , Yen Chia-Hung , Tzeng Tsai-Yu , Huang Yu-Zen , Chou Kuan-Hsien , Chang Tai-Jay , Arthur Chen Yi-Ming
Published: July 2013

Androgen plays an important role in the pathogenesis of PCa (prostate cancer). Previously, we identified GNMT (glycine N-methyltransferase) as a tumour susceptibility gene and characterized its promoter region. Besides, its enzymatic product-sarcosine has been recognized as a marker for prognosis of PCa. The goals of this study were to determine whether GNMT is regulated by androgen and to map its AREs (androgen response elements). Real-time PCR analyses showed that R1881, a synthetic AR (androgen receptor) agonist induced GNMT expression in AR-positive LNCaP cells, but not in AR-negative DU145 cells. In silico prediction showed that there are four putative AREs in GNMT-ARE1, ARE2 and ARE3 are located in the intron 1 and ARE4 is in the intron 2. Consensus ARE motif deduced from published AREs was used to identify the fifth ARE-ARE5 in the coding region of exon 1. Luciferase reporter assay found that only ARE5 mediated the transcriptional activation of R1881. ARE3 overlaps with a YY1 [Yin and Yang 1 (motif (CaCCATGTT, +1118/+1126)] that was further confirmed by antibody supershift and ChIP (chromatin immunoprecipitation) assays. EMSA (electrophoretic mobility shift assay) and ChIP assay confirmed that AR interacts with ARE5 in vitro and in vivo. In summary, GNMT is an AR-targeted gene with its functional ARE located at +19/+33 of the first exon. These results are valuable for the study of the influence of androgen on the gene expression of GNMT especially in the pathogenesis of cancer.
Are Some Parents' Interaction Styles Associated With Richer Grammatical Input?
Authors: Fitzgerald Colleen E. , Hadley Pamela A. , Rispoli Matthew
Published: July 2013

Purpose

Evidence for tense marking in child-directed speech varies both across languages (Guasti, 2002; Legate & Yang, 2007) and across speakers of a single language (Hadley, Rispoli, Fitzgerald, & Bahnsen, 2011). The purpose of this study was to understand how parent interaction styles and register use overlap with the tense-marking properties of child-directed speech. This study investigated how parent interaction style, measured by utterance function, and parent register use when asking questions interacted with verb forms in child-directed input to identify interaction styles associated with the richest grammatical input.

Method

Participants were 15 parent–toddler dyads. The communicative function of parent utterances and the form of their questions were coded from language samples of parent–child play when children were 21 months of age. Verbs were coded for linguistic form (e.g., imperative, modal, copula).

Results

Directives and reduced questions were both negatively related to input informativeness (i.e., the proportion of unambiguous evidence for tense). Other-focused descriptives were positively related to input informativeness.

Conclusion

Predictable overlap existed between the characteristics of parents' interaction styles and register use and their input informativeness. An other-focused descriptive style most strongly related to richer evidence for the +Tense grammar of English.