bluuebunny/crossref_metadata_2025 huggingface dataset:
Impacts of Stratospheric Sulfate Geoengineering on Tropospheric Ozone
Authors: Xia Lili , Nowack Peer J. , Tilmes Simone , Robock Alan
Published: May 2017

Abstract. A range of solar radiation management (SRM) techniques has been proposed to counter anthropogenic climate change. Here, we examine the potential effects of stratospheric sulfate aerosol and solar insolation reduction on tropospheric ozone and ozone at Earth’s surface. Ozone is a key air pollutant, which can produce respiratory diseases and crop damage. Using a version of the Community Earth System Model from the National Center for Atmospheric Research that includes comprehensive tropospheric and stratospheric chemistry, we model both stratospheric sulfur injection and solar irradiance reduction schemes, with the aim of achieving equal levels of surface cooling relative to the Representative Concentration Pathway 6.0 scenario. This allows us to compare the impacts of sulfate aerosol and solar dimming on atmospheric ozone concentrations. Despite nearly identical global mean surface temperatures for the two SRM approaches, solar insolation reduction increases global average surface ozone concentrations while sulfate injection decreases it. A key difference between the two geoengineering schemes is the importance of heterogeneous reactions in the photochemical ozone balance with larger stratospheric sulfate abundance, resulting in increased ozone depletion in mid- and high latitudes. This reduces the net transport of stratospheric ozone into the troposphere and thus is a key driver of the overall decrease in surface ozone. At the same time, the change in stratospheric ozone alters the tropospheric photochemical environment due to enhanced ultraviolet radiation. A shared factor among both SRM scenarios is decreased chemical ozone loss due to reduced tropospheric humidity. Under insolation reduction, this is the dominant factor giving rise to the global surface ozone increase. Regionally, both surface ozone increases and decreases are found for both scenarios, that is, SRM would affect regions of the world differently in terms of air pollution. In conclusion, surface ozone and tropospheric chemistry would likely be affected by SRM, but the overall effect is strongly dependent on the SRM scheme. Due to the health and economic impacts of surface ozone, all these impacts should be taken into account in evaluations of possible consequences of SRM.
Atmospheric organochlorine pesticides and polychlorinated biphenyls in urban areas of Nepal: spatial variation, sources, temporal trends and long range
transport potential
Authors: Pokhrel Balram , Gong Ping , Wang Xiaoping , Khanal Sanjay Nath , Ren Jiao , Wang Chuanfei , Gao Shaopeng , Yao Tandong
Published: May 2017

Abstract. The study of persistent organic pollutants (POPs) in low latitude tropical and subtropical urban cities is necessary to assess their local and global impacts on ecosystems and human health. Despite studies on levels of POPs in water, soils, and sediments, analysis of the distribution patterns, seasonality and sources of POPs in urban regions of Nepal remain limited. Polyurethane foam (PUF)-based passive air samplers were deployed in three major cities in Nepal: Kathmandu (the capital city), Pokhara and Hetauda (agricultural cities). Dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) were the dominant organochlorine pesticides in the atmosphere at all sites. The average concentrations of POPs were: ∑DDTs, 11.0–885.2 pg/m3; ∑HCHs, 4.0–2623.8 pg/m3; HCB, 2.7–186.2 pg/m3; ∑endosulfan, 1.4–34.8 pg/m3; and ∑6PCBs, 1.4–29.2 pg/m3. Isomer and metabolite ratio analyses suggested that the concentrations present were from both new and historical applications of the POPs. Vegetable production sites and their market places appeared to be the major DDT and HCH source areas. Higher atmospheric concentrations of DDT and HCH occurred during the pre-monsoon and monsoon seasons, and winter, respectively, closely associated with their local application for soil preparation and vegetable spraying. The estimated travel distances of the POPs (HCB, α-HCH, γ-HCH, and p,p'-DDT) under the Nepalese tropical climate were all above 1000 km, suggesting that high precipitation levels in the tropical climate were not enough to scavenge the POPs and that Nepal could be an important source region for POPs. Due to their close proximity and cold trapping (driven by low temperatures), the high Himalayas and the Tibetan Plateau are likely the key receptors of POPs emitted in Nepal. These results add to the information available on POPs from tropical developing countries.
Global consequences of afforestation and bioenergy cultivation on ecosystem service indicators
Authors: Krause Andreas , Bayer Anita D. , Pugh Thomas A. M. , Doelman Jonathan C. , Humpenöder Florian , Anthoni Peter , Olin Stefan , Bodirsky Benjamin L. , Popp Alexander , Stehfest Elke , Arneth Almut
Published: May 2017

Abstract. Land management for carbon storage is discussed as being indispensable for climate change mitigation because of its large potential to remove carbon dioxide from the atmosphere, and to avoid further emissions from deforestation. However, land-based mitigation's prospect of success depends on potential side-effects on important ecosystem services. Here, we use projections of future land use and land cover for different land-based mitigation options from two land-use models (IMAGE and MAgPIE) and evaluate their effects with a global dynamic vegetation model (LPJ-GUESS). In the land-use models, a cumulative carbon removal target of 130 GtC by the end of the 21st century was set to be achieved either via growth of bioenergy crops combined with carbon capture and storage, via avoided deforestation and afforestation, or via a combination of both. We compare these scenarios to a reference scenario without land-based mitigation and analyse the LPJ-GUESS simulations with the aim to assess synergies and trade-offs across a range of ecosystem service indicators: carbon sequestration, surface albedo, evapotranspiration, water runoff, crop production, nitrogen loss, and emissions of biogenic volatile organic compounds. In our mitigation simulations carbon removal by year 2099 ranged between 55 and 89 GtC, and thus lower than the removal simulated by the land-use models. Other ecosystem service indicators were influenced heterogeneously both positively and negatively, with large variability across regions and land-use scenarios. Avoided deforestation and afforestation led to an increase in evapotranspiration and enhanced emissions of biogenic volatile organic compounds, and to a decrease in albedo, runoff, and nitrogen loss. Also crop production decreased in the afforestation scenario as a result of reduced crop area, especially for MAgPIE land-use patterns. Bioenergy-based climate change mitigation was projected to affect less area globally than in the forest expansion scenarios, and resulted in less pronounced changes in most ecosystem service indicators than forest-based mitigation, but included a decrease in crop production, nitrogen loss and biogenic volatile organic compounds emissions.
Constraints on global oceanic emissions of N2O from observations and models
Authors: Buitenhuis Erik T. , Suntharalingam Parvadha , Le Quéré Corinne
Published: May 2017

Abstract. We estimate the global ocean N2O flux to the atmosphere and its confidence interval using a statistical method based on model perturbation simulations and their fit to a database of ΔpN2O (n=6136). We evaluate two submodels of N2O production. The first submodel splits N2O production into oxic and hypoxic pathways following previous publications. The second submodel explicitly represents the redox transformations of N that lead to N2O production (nitrification and hypoxic denitrification) and N2O consumption (suboxic denitrification), and is presented here for the first time. We perturb both submodels by modifying the key parameters of the N2O cycling pathways (nitrification rates, NH4+ uptake, N2O yields under oxic, hypoxic and suboxic conditions), and determine a set of optimal model parameters by minimisation of a cost function against 4 databases of N cycle observations derived from observed and model ΔpN2O concentrations. Our estimate of the global oceanic N2O flux resulting from this cost function minimisation is 2.4 ± 0.8 Tg N y−1, and is invariant to the choice of N2O submodel. These estimates suggest that the currently available observational data of surface ΔpN2O constrain the global N2O flux to a narrower range relative to the large range of results presented in the latest IPCC report.
A pseudoproxy assessment of data assimilation for reconstructing the atmosphere-ocean dynamics of hydroclimate extremes
Authors: Steiger Nathan , Smerdon Jason
Published: May 2017

Abstract. Because of the relatively brief observational record, the climate dynamics that drive multi-year to centennial hydroclimate variability are not adequately characterized and understood. Data assimilation(DA)-based paleoclimate reconstructions optimally fuse paleoclimate proxies with the dynamical constraints of climate models, thus providing a coherent dynamical picture of the past. Therefore DA is an important new tool for elucidating the mechanisms of hydroclimate variability over the last several millennia. But DA has so far remained an untested tool for global hydroclimate reconstructions. Here we explore whether or not DA can be used to skillfully reconstruct global hydroclimate variability along with the driving climate dynamics. Through a set of realistic pseudoproxy experiments we find that an established DA reconstruction approach can indeed be used to reconstruct hydroclimate at both annual and seasonal time scales. We find that temperature and hydroclimate variables are best reconstructed near the proxy sites; in particular for tree rings, we find that hydroclimate reconstructions depend critically on moisture-sensitive trees, while temperature reconstructions depend critically on temperature-sensitive trees. Real-world DA-based reconstructions will therefore likely require a spatial mixture of temperature and moisture sensitive trees to reconstruct both temperature and hydroclimate variables. Additionally, we illustrate how DA can be used to elucidate the dynamical mechanisms of drought with two examples: we examine the tropical drivers of multi-year droughts in the North American Southwest and in equatorial East Africa. This work thus provides a foundation for future DA-based hydroclimate reconstructions using real proxy networks, while also highlighting the utility of this important tool for hydroclimate research.
An explanation for the different climate sensitivities of land and
ocean surfaces based on the diurnal cycle
Authors: Kleidon Axel , Renner Maik
Published: May 2017

Abstract. Observations and climate model simulations consistently show a higher climate sensitivity of land surfaces compared to ocean surfaces, with the cause for this difference being still unclear. Here we show that this difference in temperature sensitivity can be explained by the different means by which the diurnal variation in solar radiation is buffered. While ocean surfaces buffer the diurnal variations by heat storage changes below the surface, land surfaces buffer it mostly by heat storage changes above the surface in the lower atmosphere that are reflected in the diurnal growth of a convective boundary layer. Storage changes below the surface allow the ocean surface-atmosphere system to maintain turbulent fluxes over day and night, while the land surface-atmosphere system maintains turbulent fluxes only during the daytime hours when the surface is heated by absorption of solar radiation. This shorter duration of turbulent fluxes on land then results in a greater sensitivity of the land surface-atmosphere system to changes in the greenhouse forcing because nighttime temperatures are then shaped by radiative exchange only, which are more sensitive to changes in greenhouse forcing. We use a simple, analytic energy balance model of the surface-atmosphere system in which turbulent fluxes are constrained by the maximum power limit to estimate the effects of these different means to buffer the diurnal cycle on the resulting temperature sensitivities. The model predicts that land surfaces have a 50% greater climate sensitivity than ocean surfaces, and that the nighttime temperatures on land increase about twice as much as daytime temperatures because of the absence of turbulent fluxes at night. Both predictions compare very well with observations and CMIP 5 climate model simulations. Hence, the greater climate sensitivity of land surfaces can be explained by its buffering of diurnal variations of solar radiation in the lower atmosphere.
Exploratory studies into seasonal flow forecasting potential for large lakes
Authors: Sene Kevin , Tych Wlodek , Beven Keith
Published: May 2017

Abstract. In seasonal flow forecasting applications, one factor which can help predictability is a significant hydrological response time between rainfall and flows. On account of storage influences, large lakes therefore provide a useful test case although, due to the spatial scales involved, there are a number of modelling challenges related to data availability and understanding the individual components in the water balance. Here some possible model structures are investigated using a 10 range of stochastic regression and transfer function techniques with additional insights gained from simple analytical approximations. The methods were evaluated using records for two of the largest lakes in the world – Lake Malawi and Lake Victoria – with forecast skill demonstrated several months ahead using water balance models formulated in terms of net inflows. In both cases slight improvements were obtained for lead times up to 4–5 months from including climate indices in the data assimilation component. The paper concludes with a discussion of the relevance of the results to operational flow 15 forecasting systems for other large lakes.
Consistency assessment of rating curve data in various locations
using Bidirectional Reach (BReach)
Authors: Van Eerdenbrugh Katrien , Van Hoey Stijn , Coxon Gemma , Freer Jim , Verhoest Niko E. C.
Published: May 2017

Abstract. When estimating discharges through rating curves, temporal data consistency is a critical issue. In this research, consistency in stage-discharge data is investigated using a methodology called Bidirectional Reach (BReach), which departs from a (in operational hydrology) commonly used definition of consistency. A period is considered to be consistent if no consecutive and systematic deviations from a current situation occur that exceed observational uncertainty. Therefore, the capability of a rating curve model to describe a subset of the (chronologically sorted) data is assessed in each observation by indicating the outermost data points for which the rating curve model behaves satisfactory. These points are called the maximum left or right reach, depending on the direction of the investigation. This temporal reach should not be confused with a spatial reach (indicating a part of a river). Changes in these reaches throughout the data series indicate possible changes in data consistency and if not resolved could introduce additional errors and biases. In this research, various measurement stations in the UK, New Zealand and Belgium are selected based on their significant historical ratings information and their specific characteristics related to data consistency. For each country, regional information is maximally used to estimate observational uncertainty. Based on this uncertainty, a BReach analysis is performed and subsequently, results are validated against available knowledge about the history and behavior of the site. For all investigated cases, the methodology provides results that appear consistent with this knowledge of historical changes and facilitates thus a reliable assessment of (in)consistent periods in stage-discharge measurements. This assessment is not only useful for the analysis and determination of discharge time series, but also to enhance applications based on these data (e.g., by informing hydrological and hydraulic model evaluation design about consistent time periods to analyze).
BEYOND POINT CLOUDS AND VIRTUAL REALITY.
INNOVATIVE METHODS AND TECHNOLOGIES FOR THE PROTECTION AND
PROMOTION OF CULTURAL HERITAGE
Authors: Canevese E. P. , De Gottardo T.
Published: May 2017

Abstract. The morphometric and photogrammetric knowledge, combined with the historical research, are the indispensable prerequisites for the protection and enhancement of historical, architectural and cultural heritage. Nowadays the use of BIM (Building Information Modeling) as a supporting tool for restoration and conservation purposes is becoming more and more popular. However this tool is not fully adequate in this context because of its simplified representation of three-dimensional models, resulting from solid modelling techniques (mostly used in virtual reality) causing the loss of important morphometric information. One solution to this problem is imagining new advanced tools and methods that enable the building of effective and efficient three-dimensional representations backing the correct geometric analysis of the built model. Twenty-year of interdisciplinary research activities implemented by Virtualgeo focused on developing new methods and tools for 3D modeling that go beyond the simplified digital-virtual reconstruction used in standard solid modeling. Methods and tools allowing the creation of informative and true to life three-dimensional representations, that can be further used by various academics or industry professionals to carry out diverse analysis, research and design activities. Virtualgeo applied research activities, in line with the European Commission 2013’s directives of Reflective 7 – Horizon 2020 Project, gave birth to GeomaticsCube Ecosystem, an ecosystem resulting from different technologies based on experiences garnered from various fields, metrology in particular, a discipline used in the automotive and aviation industry, and in general mechanical engineering. The implementation of the metrological functionality is only possible if the 3D model is created with special modeling techniques, based on surface modeling that allow, as opposed to solid modeling, a 3D representation of the manufact that is true to life. The advantages offered by metrological analysis are varied and important because they permit a precise and detailed overview of the 3D model’s characteristics, and especially the over time monitoring of the model itself, these informations are impossible to obtain from a three-dimensional representation produced with solid modelling techniques. The applied research activities are also focused on the possibility of obtaining a photogrammetric and informative 3D model., Two distinct applications have been developed for this purpose, the first allows the classification of each individual element and the association of its material characteristics during the 3D modelling phase, whilst the second allows segmentations of the photogrammetric 3D model in its diverse aspects (materic, related to decay, chronological) with the possibility to make use and to populate the database, associated with the 3D model, with all types of multimedia contents.
Risk factors and perceived restoration in a town destroyed by the 2010 Chile tsunami
Authors: Martínez Carolina , Rojas Octavio , Villagra Paula , Aránguiz Rafael , Sáez-Carrillo Katia
Published: May 2017

Abstract. A large earthquake and tsunami took place in February 2010, affecting a significant part of the Chilean coast (Maule earthquake, Mw of 8.8). Dichato (37° S), a small town located on Coliumo Bay, was one of the most devastated coastal areas and is currently under reconstruction. Therefore, the objective of this research is to analyze the risk factors that explain the disaster in 2010, as well as perceived restoration 6 years after the event. Numerical modeling of the 2010 Chile tsunami with four nested grids was applied to estimate the hazard. Physical, socioeconomic and educational dimensions of vulnerability were analyzed for pre- and post-disaster conditions. A perceived restoration study was performed to assess the effects of reconstruction on the community. It was focused on exploring the capacity of newly reconstructed neighborhoods to provide restorative experiences in case of disaster. The study was undertaken using the perceived restorativeness scale. The vulnerability variables that best explained the extent of the disaster were housing conditions, low household incomes and limited knowledge about tsunami events, which conditioned inadequate reactions to the emergency. These variables still constitute the same risks as a result of the reconstruction process, establishing that the occurrence of a similar event would result in a similar degree of devastation. For post-earthquake conditions, it was determined that all neighborhoods have the potential to be restorative environments soon after a tsunami. However, some neighborhoods are still located in areas devastated by the 2010 tsunami and again present high vulnerability to future tsunamis.
Response to Filchner-Ronne Ice Shelf cavity warming in a coupled
ocean–ice sheet model. Part I: The ocean perspective
Authors: Timmermann Ralph , Goeller Sebastian
Published: May 2017

Abstract. A Regional Antarctic and Global Ocean (RAnGO) model has been developed to study the interaction between the world ocean and the Antarctic ice sheet. The coupled model is based on a global implementation of the Finite Element Sea-ice Ocean Model (FESOM) with a mesh refinement in the Southern Ocean, particularly in its marginal seas and in the sub-ice shelf cavities. The cryosphere is represented by a regional setup of the ice flow model RIMBAY comprising the Filchner-Ronne Ice Shelf and the grounded ice in its catchment area up to the ice divides. At the base of the RIMBAY ice shelf, melt rates from FESOM's ice-shelf component are supplied. RIMBAY returns ice thickness and the position of the grounding line. The ocean model uses a pre-computed mesh to allow for an easy adjustment of the model domain to a varying cavity geometry. RAnGO simulations with a 20th-century climate forcing yield realistic basal melt rates and a quasi-stable grounding line position close to the presently observed state. In a centennial-scale warm-water-inflow scenario, the model suggests a substantial thinning of the ice shelf and a local retreat of the grounding line. The potentially negative feedback from ice-shelf thinning through a rising in-situ freezing temperature is more than outweighed by the increasing water column thickness in the deepest parts of the cavity. Compared to a control simulation with fixed ice-shelf geometry, the coupled model thus yields a slightly stronger increase of ice-shelf basal melt rates.
Texture analysis of experimentally deformed Black Hills Quartzite
Authors: Kilian Rüdiger , Heilbronner Renée
Published: May 2017

Abstract. The textures of three samples of Black Hills quartzite (BHQ) deformed experimentally in the dislocation creep regime 1, 2 and 3 (according to Hirth and Tullis, 1992) have been analysed by EBSD. All samples were deformed to relatively high strain, within a temperature range of 65° and identical displacement rates and are almost entirely composed of dynamically recrystallized grains. A texture transition from peripheral c-axes in regime 1 to a central c-axis maximum in regime 3 is observed. Separate pole figures are calculated for different grain sizes, aspect ratios and long axis trend (θ) of grains, and high and low levels of intragranular deformation intensity as measured by the grain kernel average misorientation (gKAM). Misorientation relations are analysed for different texture components (named Y- B- R- and σ, with reference to previously published prism, basal, rhomb and σ1 – grains). Results show that regime 1 and 3 correspond to clear end member textures with regime 2 being transitional. Texture strength and the development of a central c-axis maximum from a girdle distribution depends on deformation intensity at the grain scale and on the contribution of dislocation creep which increases towards regime 3. Combined with calculations of resolved shear stresses and misorientation analysis, it becomes clear that the peripheral c-axis maximum in regime 1 is not due to deformation by basal – slip. We interpret the texture transition as a result of different texture forming processes, one being more efficient at high stresses (formation of grains with peripheral c-axes), the other depending on strain (dislocation glide involving prism and rhomb slip systems), and not as a result of a temperature dependent activity of different slip systems.
Analogue earthquakes and seismic cycles: experimental modelling across timescales
Authors: Rosenau Matthias , Corbi Fabio , Dominguez Stephane
Published: May 2017

Abstract. Earth deformation is a multi-scale process ranging from seconds (seismic deformation) to millions of years (tectonic deformation). Bridging short- and long-term deformation and developing seismotectonic models has been a challenge in experimental tectonics for more than a century. Since the formulation of Reid's elastic rebound theory 100 years ago, laboratory mechanical models combining frictional and elastic elements have been used to study the dynamics of earthquakes. In the last decade, with the advent of high-resolution monitoring techniques and new rock analogue materials, laboratory earthquake experiments have evolved from simple spring-slider models to scaled analogue models. This evolution was accomplished by advances in seismology and geodesy along with relatively frequent occurrences of large earthquakes in the past decade. This coincidence has significantly increased the quality and quantity of relevant observations in nature and triggered a new understanding of earthquake dynamics. We review here the developments in analogue earthquake modelling with a focus on those seismotectonic scale models that are directly comparable to observational data on short to long timescales. We lay out the basics of analogue modelling, namely scaling, materials and monitoring, as applied in seismotectonic modelling. An overview of applications highlights the contributions of analogue earthquake models in bridging timescales of observations including earthquake statistics, rupture dynamics, ground motion, and seismic-cycle deformation up to seismotectonic evolution.
RETÓRICA E CRÍTICA DA LINGUAGEM EM NIETZSCHE
Authors: Barbosa Rodrigo Francisco
Published: May 2017

O objetivo deste artigo é demonstrar como o reconhecimento de uma “virada retórica” em Nietzsche resulta em uma demarcada “tensão” que caracteriza certa ambiguidade acerca da linguagem em seu pensamento. Deste modo, no âmbito de apresentar essa mobilização em Nietzsche no interior da discussão sobre a linguagem, examinamos três aspectos fundamentais desse direcionamento àquilo que constitui uma impossibilidade semântica: primeiro, identificamos a chamada “virada retórica”; em segundo lugar, aprofundamos o tema a partir da análise da adesão de Nietzsche à tese de Gustav Gerber de que a retórica é a “essência” da linguagem; e, em terceiro lugar, perscrutamos a legitimidade da distinção entre linguagem própria (natural) e linguagem imprópria (retórica). Portanto, essa problematização da linguagem realizada por Nietzsche aparece desdobrada ao longo de sua obra e pode ser observada a partir da heterogeneidade da discursividade que seus escritos tardios contemplam.
An Empirical Application of Goal Programming and AHP in Real Estate Assessment
Authors: Jamshidi Hossein
Published: May 2017

The Goal Programming (GP) is one of the many models which have been developed to deal with the multiple objectives decision-making problems. This model allows taking into account, simultaneously, many objectives while the decision-maker is seeking the best solution from among a set of feasible solutions. At first, the aim of this study is to compare the objectives of the decision maker based on the Analytical Hierarchy Process (AHP) and to rank the objectives according to the AHP process and once the objectives are set then apply the GP to the facility allocation in a real estate rental property.  The objective of decision maker is not only to maximize profit rather the decision maker has multiple objective to achieve. The methodology presented in this study can help the decision maker to formulate viable location strategies in the volatile and complex facility allocation environment. This is an empirical study applied to a local business developer utilizing multi objective decision analysis tools.
Comparison of Hand and Semiautomatic Tracing Methods for Creating Maxillofacial Artificial Organs using Sequences of Computed Tomography (CT) and Cone Beam Computed Tomography (CBCT) Images
Authors: Szabo Bence T. , Aksoy Seçil , Repassy Gabor , Csomo Krisztian , Dobo-Nagy Csaba , Orhan Kaan
Published: May 2017

Introduction

The aim of this study was to compare the paranasal sinus volumes obtained by manual and semiautomatic imaging software programs using both CT and CBCT imaging.

Methods

121 computed tomography (CT) and 119 cone beam computed tomography (CBCT) examinations were selected from the databases of the authors’ institutes. The Digital Imaging and Communications in Medicine (DICOM) images were imported into 3-dimensonal imaging software, in which hand mode and semiautomatic tracing methods were used to measure the volumes of both maxillary sinuses and the sphenoid sinus. The determined volumetric means were compared to previously published averages.

Results

Isometric CBCT-based volume determination results were closer to the real volume conditions, whereas the non-isometric CT-based volume measurements defined coherently lower volumes. By comparing the 2 volume measurement modes, the values gained from hand mode were closer to the literature data. Furthermore, CBCT-based image measurement results corresponded to the known averages.

Conclusions

Our results suggest that CBCT images provide reliable volumetric information that can be depended on for artificial organ construction, and which may aid the guidance of the operator prior to or during the intervention.
Comparison between Mononucleotide and Dinucleotide Marker Panels in Gastric Cancer with Loss of hMLH1 or hMSH2 Expression
Authors: Kim Jeong Goo , Shin Soyoung , Park Joonhong
Published: May 2017

Background

DNA mismatch repair deficiency is an important molecular mechanism of genetic instability in gastric cancer, and a high instability at microsatellites is associated with favorable prognosis. We compared mononucleotide and dinucleotide microsatellite instability (MSI) marker panels in 56 paired gastric tumor and normal samples.

Methods

The mononucleotide marker panel (mono panel) consisted of 8 markers: BAT25, BAT26, BAT40, BAT-RII, NR21, NR22, NR24 and NR27. The dinucleotide marker panel (di panel) contained D2S123, D5S346, D17S250, D17S261, D17S520, D18S34 and D18S58. The NCI panel was used as reference panel.

Results

Among 13 gastric tumors showing no hMLH1 or hMSH2 expression, 8 MSI-H (high) and 5 MSI-L (low) were identified. The analytical sensitivities of the NCI, mono and di panels to detect unstable MSI were 61.5% (8/13), 76.9% (10/13) and 84.6% (11/13), respectively. The size change of allele shift was statistically greater in the mono panel than in the di panel (p = 0.02 by Mann-Whitney U-test). The BAT40 (69.2%, 9/13) and D18S34 (76.9%, 10/13) markers showed high sensitivity for determination of MSI status.

Conclusions

To improve the detection rate of MSI in gastric cancer with loss of hMLH1 or hMSH2 expression, the kind of MSI marker may need to be considered more, instead of the repetitive type of marker. Thus, an MSI panel designed with a combination of both BAT40 and D18S34 is suggested for providing more accurate and sensitive MSI analysis in gastric cancer.
223Ra-dichloride Response in a Patient with Paget Disease and Bone Metastases Secondary to Castration-Resistant Prostate Cancer
Authors: Cañamaque Lina García , Parada Cristina Rioja , De la Peña Paloma García
Published: May 2017

Purpose

Paget disease is commonly asymptomatic and discovered when an imaging test is performed for another clinical indication or when elevated serum alkaline phosphatase is found. Bone pain usually appears late in the disease process and is only present in a minority of patients. For diagnosis, X-ray and bone scan are the most recommended imaging methods; radionuclide imaging of the skeleton has become the standard, since it is the most sensitive test for detecting increased bone activity. For treatment, either bisphosphonates or calcitonin are recommended.

Methods

We present a 74-year-old patient diagnosed with prostate cancer in 2001 who developed bone metastases concomitant with a Paget bone disease.

Results

This patient received treatment with Ra-223, having stable disease in bone scan and no relevant toxicities.

Conclusions

There is no clinical experience with Ra-223 and Paget disease, since it is characterized classically as a high bone turnover disease and therefore there is no rationale to administer a drug that has a high bone affinity. Nevertheless, Ra-223 is not contraindicated.
Imaging Technologies in the Diagnosis and Treatment of Acute Pyelonephritis
Authors: Enikeev Dmitry V. , Glybochko Petr , Alyaev Yuriy , Enikeev Mikhail , Rapoport Leonid
Published: May 2017

Purpose

The aim of this study was to evaluate the possibilities of ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) in diagnosing acute pyelonephritis (AP) and renal abscess.

Patients and Methods

Two hundred and seven patients with AP were followed up from 2010 throughout 2015. All the patients were divided into three groups. Group 1 included 113 (54.6%) patients with acute nonobstructive pyelonephritis; group 2 included 33 (15.9%) patients with acute obstructive pyelonephritis; and group 3 included 61 (29.5%) pregnant female patients with AP. All 207 patients with AP underwent ultrasound examination of the kidneys. Computed tomography (CT) was performed in 87 patients (42.0%). MRI was performed in 14 patients (6.7%).

Results

We identified the ultrasound (US), magnetic resonance (MR), and CT-signs of acute renal inflammation at different stages of the process. The main us-signs were decreased mobility of the kidney, its enlargement, thickened parenchyma, hydrophilic parenchyma and an impairment of corticomedullary differentiation. The typical CT-signs of AP were enlargement of the kidney with its thickened parenchyma and an impairment of corticomedullary differentiation. The main MR-signs of AP were enlargement of the kidney (>12 cm lengthwise), thickened parenchyma (<2 cm in the median segment of the kidney) and an impairment of corticomedullary differentiation.

Conclusions

Assessment of the structural and functional state of renal parenchyma and the upper urinary tract using techniques such as ultrasonography, CT, MRI contributes to more efficacious treatment of patients at different stages of AP and timely drainage with properly adjusted pathogenetic therapy at the infiltrative stage is instrumental in preventing purulent destructive forms of AP.
Near-Infrared Fluorescence with Indocyanine Green for Diagnostics in Urology: Initial Experience
Authors: Morozov Andrey O. , Alyaev Yuri G. , Rapoport Leonid M. , Tsarichenko Dmitrii G. , Bezrukov Eugene A. , Butnaru Denis V. , Sirota Eugene S.
Published: May 2017

Introduction

Fluorescence imaging with indocyanine green is used in urology for the detection of sentinel lymph nodes and identification of prostate margins in radical prostatectomy for delineation of resection zone and selective clamping of vessels in partial nephrectomy; for identification and evaluation of length of ureteral strictures; for assessment of perfusion and viability of anastomoses during reconstructive stage of cystectomy. Safety of this technique is proven, while its diagnostic value and usefulness is still controversial.

Methods

This pilot study of using the SPY Elite Fluorescence Imaging System for diagnostics was performed in the I.M. Sechenov First Moscow State Medical University. Ten patients were enrolled: four patients underwent retropubic RP and lymph node dissection, five patients underwent partial nephrectomy, and one patient underwent ureteroplasty. Fluorophore was injected transrectally with TRUS guidance during RP in order to assess the lymph nodes. During partial nephrectomy, the compound was injected intravenously to differentiate the tumor from parenchyma by its blood supply. During ureteroplasty, the indocyanine green solution was injected into the renal pelvis to dye the ureter and locate the stricture.

Results

Sensitivity of this technique for visualization of sentinel lymph nodes was 100%, and specificity was 73.3%. In patients who underwent partial nephrectomy, all lesions were malignant and hypofluorescent when compared with healthy parenchyma. SPY allowed us to determine the location and extension of the stricture during ureteroplasty. No hypersensitivity reactions or complications were observed during injection of the compound.
Complications and Prostate Cancer Diagnosis Rate of TRUS Prostate Biopsies Using 16 and 18G Needles by Clavien Scoring
Authors: Ozcan Serkan , Akif Diri Mehmet , Bagcioglu Murat , Karakan Tolga , Aydın Arif
Published: May 2017

Aim

We aimed to compare the 18 and 16-Gauge (G) needles used in transrectal ultrasonography (TRUS)-guided needle biopsy for cancer detection rates and complications using the Clavien Scoring System.

Materials and Methods

The 80 patients who were included in the study were randomized and divided into two groups. Group 1 (n = 36) had a TRUS-guided prostate biopsy with an 18G needle and Group 2 had a 16G needle (n = 44). The hematuria, bleeding assessment, and infection events were evaluated on a daily basis. These complications were graded according to the Clavien Scoring.

Results

In Group 1, only five (13%) patients were diagnosed with prostate cancer, and three patients were reported to have atypical small acinar proliferation (ASAP). In Group 2, 16 (36%) patients were diagnosed with prostate cancer and one patient was reported to have ASAP. The difference in the prostate cancer detection rate between the groups was statistically significant. According to the Clavien grading system, the complications were at the Grade 1 level in 25 people in Group 1 in 29 people in Group 2. Grade 2 level complications were not observed in either group. While one person was Grade 3 in Group 1, two people in Group 2 had this rate. There were no significant differences between the groups.

Conclusions

We found that cancer detection rate increased by increasing the thickness of the needle used in TRUS-guided prostate biopsy without any increase in the complications.
Forty-eight hours return visits at Hamad General Hospital Emergency Department on January 2015
Authors: Abbasy Mohamed E. , Abosalah Salem , Mohamed Aboubakr Mohamed Awad , Tqm Adel Zahran , Felaya Ahmed , Awad Ahmed Alaa , Elmoheen Amr , Hereiz Ayman M. , Issaoui Besma Ayari Ep , Badawy Ehab , Ebeem Mahmoud Saqr , Ebem Mohamed Fawzy Elsayed , Ebem Mohamed Qotb , Sultan Mohamed , Jaffer Rana , Tq Ramy Abdelkader Ebem , Alkahky Sherif
Published: May 2017

Background: Hamad General Hospital (HGH) Emergency Department (ED) provided 465,942 patient visits in 2014. (ED) use has increased annually resulting in overcrowding, longer wait periods for service and increased stress on health care workers. Much attention has been paid to factors contributing to this increased usage such as the return visit of an (ED) patient within 48 hours of the initial visit. 48 hours is the benchmark time period used in measuring (ED) return visits utilized by many countries and it became a mandatory quality indicator of performance by the Supreme Council of Health in Qatar on April 2015. This study was conducted to identify factors associated with scheduled and unscheduled 48 hours return visits to serve as a basis for a Quality Improvement Project (QIP) for development of interventions to decrease unscheduled returns.

Methods: An exploratory quantitative study using a descriptive correlational design was performed. The sample consisted of all patients had a return visits to (ED) within 48 hours from the discharge time during January 2015 at the study facility. Data were abstracted from electronic patients’ records utilizing the data collection tool, all electronic records was reviewed by experienced emergency physicians.

Results: For the study month of January 2015 there were 1023 return visits within 48 hours from the discharge time (2%) out of 42981 (ED) patients. 906 visits (89%) was unplanned out of them 102 visits (11%) was clinically significant. 85 cases(9%) were admitted on the return visit and we had no mortality cases. Abdominal pain was the main presenting complaint (28%) of all revisits followed by musculoskeletal pain (13%) for patients whom presenting with the same complaint.

Conclusion: Abdominal pain is the most frequent complaint associated with unscheduled return visits. Further Study is important to design and implement interventions to decrease the frequency of unscheduled returns.
Patients who leave without being seen: Al Wakra Hospital experience and analysis of associated factors
Authors: Calubaquib Ma. Victoria , Abdel Aziz Hani Ramadan Farag , Basong Elena , Del Castillo Maria Jennifer , Khader Hisham M Kh. , Hamad Alla El Fadil , Al Khawaldeh Amjad , Khaled Ahmad Muayad Kasem
Published: May 2017

Background: The rate of patients who arrive at the Emergency Department (ED) but leave before being seen (LWBS) is considered an important marker of the quality of care.

Objectives: To evaluate the rate of LWBS at ED in Al Wakra Hospital (AWH) and to identify predictive factors associated with LWBS.

Methods: This was a retrospective study of patients who left the Emergency Department without being seen by physicians between January 1, 2015 and May 31, 2015. Factors associated with LWBS such as the age, sex, time of the day, day of the week, median ED waiting times and common ED presentation were analyzed.

Results: Out of 95,375 patient visits; there were 426 cases of LWBS over the 5-month period. The highest rate of LWBS was seen on the month of March. Independent factors associated with LWBS patients include patients who are middle age (19-43 years), female (56%), and patients being presented at non-critical areas (100%), night shift visits (46%), on weekend (52.8%). Musculoskeletal complaint was the most frequent complaint associated with LBWS (31%) and the median waiting time was 45 minutes among LBWS patients.

Conclusion: The rate of patients leaving without being seen at ED in AWH is very low. More investigations need to be conducted to improve LWBS rate during night and weekends.
Status of cold chain management among health care providers in Qatar: Primary health care center-based intervention study
Authors: Salem Enayat Hanafi , Alhajri Mohammed , Al Romaihi Hamad , Rady Mervat , Al-Kohji Sadriya , Kumar Nanda , Al Kuwari Mohamed , Al Yafei Amal
Published: May 2017

Objective: The study aimed to measure the status of cold chain management among primary health care professionals at primary healthcare centers (PHCC) in Qatar.

Methods: A cross-sectional design with pre-post-intervention study was conducted, and 570 primary health professionals were selected from 21 PHCCs using random sampling. A structured self-administered questionnaire was used to collect data regarding the status of cold chain system of healthcare workers before and after educational intervention.

Results: Of the 570 subjects, 492 (86.3%) participated in the post-intervention evaluation. cold chain management, before the intervention six elements were present in all of the PHCCs (100%), eight were present in >80%, another eight were present in 60–80%, while 13 were present in < 60%. These figures improved to 8, 13, 4, and 10, respectively, after the intervention.

Conclusion: In Qatar, The current status of cold chain status among primary healthcare workers had significantly improved after intervention. The practices of health professionals were also found to be adequate. Therefore, it is recommended that all health professionals working in PHCCs should receive mandatory cold chain management training to ensure delivery of safe and effective vaccines in Qatar.

Keywords: KAP, cold chain, primary health care center, immunization, PHC, Qatar
Pre-notification of healthcare responders reduces the risk of exposure to infectious diseases
Authors: Bounouh Sonia Sliman
Published: May 2017

Background: The ambulance service communication center is the first access point of the public to the health care services in the state of Qatar. It's receiving between 400 and 600 emergency calls per day which are processed through a very robust and consistent workflow, for the aim to triage the emergency incidents and distinguish high and low acuity patients and send an adequate response. Within these emergency calls there are cases that will be recognized as associated with communicable diseases where the healthcare responders are at high risk of exposure.

Aims: Protecting healthcare workers from infectious diseases and controlling exposure by implementing an attentive communication network.

Methods: HMC-AS communications center implemented a communicable disease screening procedure for calls coming from Primary health centers, Hospitals and community. To identify potential infectious patients and PRE-NOTIFY: The responding crew and prompt the use of proper Personal Protective Equipment; The receiving facility to activate their procedure.

Summary of results: The Screening procedure played an important role in minimizing the exposure of the pre-hospital care responders and improved the hospital preparedness in receiving infectious patients.

Conclusion: The communication officer's compliance to the screening criteria showed an improvement and this ensured that the PRE-NOTIFICATION is done properly in a timely manner.
Risk assessment of dengue fever in Qatar
Authors: Himatt Sayed
Published: May 2017

Background: Dengue Fever constitutes a major international public health concern due to rapid expansion of geographic distribution of the virus and the mosquito vector of the disease. In this paper we aim to review the risk of Dengue Fever introduction to Qatar.

Methods: Review of the Literature for the factors responsible for the worldwide spread of dengue fever and assess these factors in Qatar.

Results: Internationally, the Global Climate Change is believed to be responsible of Dengue geographical expansion. High Temperature and humidity in Qatar are suitable climatic conditions for breeding of Dengue vectors Aedes aegypti and albopticus. The rapid urbanization in Qatar constitutes a favorable environment for breeding sites of Dengue vectors, as the mosquito prefers to breed in artificial containers such as discarded tires, drums, cans, buckets, flower pots, and vases. High number of international travelers, especially form dengue endemic countries to Qatar is a very important risk factor. The rapid human population growth in Qatar if combined with circulation of different dengue virus serotypes is an important risk factor for development of sever forms of Dengue Fever. Unspecific clinical presentation in addition to presence of asymptomatic dengue cases poses a challenge to the diagnosis capability of medical doctors in Qatar and hence to under reporting of dengue.

Conclusion: Dengue Fever is an imminent risk to Qatar. Entomological survey is needed to determine the presence, capacity and density of Dengue Vector in Qatar. Strengthen Dengue surveillance in international travelers will work as sentinel for dengue risk in Qatar.