bluuebunny/crossref_metadata_2025 huggingface dataset:
In vivo Pharmacological investigation of leaf of Polygonum hydropiper (L.)
Authors: Akhter Rumana , Haque Md Aminul , Bhuiyan Mohiuddin Ahmed , Shahriar Mohamad
Published: January 2014

The present study was planned to evaluate the anti-nociceptive, gastro intestinal motility, anti-pyretic and acute toxicity studies of leaf extract of Polygonum hydropiper leaves in albino mice following oral administration. The results showed that the anti-nociceptive activity in the scale of ethanol > n-hexane > petroleum ether > chloroform > methanol extract showed a significant result compared to diclofenac sodium. Chloroform extract showed significant results on gastro intestinal motility test. Ethanol & chloroform extracts showed considerable reduction of temperature at higher doses within 1st hour on yeast induced pyrexia in albino mice. Highest dose introduced as 1000, 2000 & 4000 mg/kg body weight of each extracts in acute toxicity test did not shown any sign of toxicity in albino mice in one week observation. Dhaka Univ. J. Pharm. Sci. 12(2): 165-169, 2013 (December) DOI: http://dx.doi.org/10.3329/dujps.v12i2.17619
Formulation and evaluation of compression Coated tablets of Lornoxicam for Targeting early morning peak symptoms of Rheumatoid arthritis
Authors: Hadi Mohd Abdul , Rao NG Raghavendra , Rao A Srinivasa
Published: January 2014

In the present research work, we have designed a pulsatile formulation of lornoxicam to treat rheumatoid arthritis as per the chronotherapeutic pattern of the disease. Core tablets were prepared by incorporating different concentration of disintegrants and were compressed in between different concentration and combination of hydrophobic and hydrophilic polymers. The core and compression coated tablets were subjected to pre-formulation, physicochemical, in-vitro drug release and stability studies. FTIR and DSC studies revealed that there was not any chemical reaction between pure drug lornoxicam and polymers. The pre and post-compressional parameters of tablets were also found to be within limits. The core tablets which were incorporated with 10% of crospovidone were found to be as most fastly disintegrating. Our optimized formulation F-5 releases lornoxicam after a lag time of 5.5±0.7 hours and 99.81±0.81% upto 8 hours. Stability was also found for the optimized formulation according to ICH guidelines. Dhaka Univ. J. Pharm. Sci. 12(2): 109-117, 2013 (December) DOI: http://dx.doi.org/10.3329/dujps.v12i2.17620
The in vitro Antimycobacterial investigation of some basic meta-/para-Alkoxyphenylcarbamic Esters Bearing 4-(4-Fluoro/2-methoxyphenyl)piperazin-1-yl fragment
Authors: Malik Ivan , Sedlarova Eva , Csollei Jozef , Stanzel Lukas , Sichrovska Lubica , Stolarikova Jirina
Published: January 2014

Following previous systematical research of ortho-/meta-/para-alkoxyphenylcarbamic acid esters as antimycobacterially active compounds, the set of the derivatives containing meta-/para-alkoxyphenylcarbamoyloxy and 4-(4-fluorophenyl/2-methoxyphenyl)piperazin-1-yl moieties were tested for their in vitro activity against tuberculous strain of Mycobacterium (M.) tuberculosis CNCTC My 331/88 as well as against potential pathogenic strains of M. kansasii CNCTC My 235/80, M. avium CNCTC My 330/88 and M. kansasii 6 509/96, respectively, by applying the micromethod for the determination of the minimum inhibitory concentration (MIC). It is concludut that the molucules posscssed selatively promising activity against M. Tuberculasis and M. Kansas!!. Dhaka Univ. J. Pharm. Sci. 12(2): 103-107, 2013 (December) DOI: http://dx.doi.org/10.3329/dujps.v12i2.17621
4-Hydroxy-trans-cinnamate Derivatives and Triterpene from Barleria cristata
Authors: Chowdhury Nipa , Hasan Abdullah Al , Tareq Fakir Shahidullah , Ahsan Monira , Azam ATM Zafrul
Published: January 2014

Barleria cristata is an important medicinal plant of Bangladesh. Many compounds of diverse biological activities were isolated from different Barleria species, including irridoids, flavonoids and phenylethanoid derivatives in addition to other groups of chemical constituents. This paper presents the chemical investigation of the whole plants of B.cristata. Classic phytochemical investigation of organic extracts of the whole plants of B. cristata together with spectroscopic methods led to the isolation and characterization of 4-hydroxy-trans-cinnamate derivatives (1-3) and a triterpene, namely oleanolic acid (4). Dhaka Univ. J. Pharm. Sci. 12(2): 143-145, 2013 (December) DOI: http://dx.doi.org/10.3329/dujps.v12i2.17623
Anti-pancreatic Cancer potential of Secalonic acid derivatives from Endophytic Fungi isolated from Ocimum basilicum
Authors: Shoeb M , Hoque ME , Thoo-Lin PK , Nahar N
Published: January 2014

The word endophyte means in the plant and refers to all microorganisms that live in the intercellular spaces of stems, petioles, roots and leaves of plants causing no apparent symptoms of disease. Seven endophytic fungi were isolated from the medicinal plant of Ocimum basilicum L. The fungal strain, labeled as 2L, was cultivated at large scale on the potato dextrose agar semi solid medium and was extracted with ethyl acetate. Normal phase silica gel column chromatography of the ethyl acetate extract afforded ergosterol (1), secalonic acid A (2) and secalonic acid D (3). The structures of these compounds (1-3) were elucidated unequivocally by UV, IR, MS, a series of 1D & 2D NMR analyses. The cytotoxicity of these compounds was evaluated by the MTT assay against human pancreatic cancer cell line. Secalonic acid A and secalonic acid D exhibited significant anti-pancreatic cancer activity with IC50 values of 7.3 and 1.6 ?M, respectively. Dhaka Univ. J. Pharm. Sci. 12(2): 91-95, 2013 (December) DOI: http://dx.doi.org/10.3329/dujps.v12i2.17624
Membrane Stabilizing and Cytotoxic Activities of Different Kupchan Partitionates of Oroxylum indicum (L.) Vent. Leaf and Bark Extracts
Authors: Aktar Fahima , Kuddus Md Ruhul , Kabir Shaila , Rashid Mohammad A , Chakma Ketoki
Published: January 2014

Abstract not availableDhaka Univ. J. Pharm. Sci. 12(2): 181-183, 2013 (December) DOI: http://dx.doi.org/10.3329/dujps.v12i2.17625
Exploration and Development of High Entropy Alloys for Structural Applications
Authors: Miracle Daniel , Miller Jonathan , Senkov Oleg , Woodward Christopher , Uchic Michael , Tiley Jaimie
Published: January 2014

We develop a strategy to design and evaluate high-entropy alloys (HEAs) for structural use in the transportation and energy industries. We give HEA goal properties for low (≤150 °C), medium (≤450 °C) and high (≥1,100 °C) use temperatures. A systematic design approach uses palettes of elements chosen to meet target properties of each HEA family and gives methods to build HEAs from these palettes. We show that intermetallic phases are consistent with HEA definitions, and the strategy developed here includes both single-phase, solid solution HEAs and HEAs with intentional addition of a 2nd phase for particulate hardening. A thermodynamic estimate of the effectiveness of configurational entropy to suppress or delay compound formation is given. A 3-stage approach is given to systematically screen and evaluate a vast number of HEAs by integrating high-throughput computations and experiments. CALPHAD methods are used to predict phase equilibria, and high-throughput experiments on materials libraries with controlled composition and microstructure gradients are suggested. Much of this evaluation can be done now, but key components (materials libraries with microstructure gradients and high-throughput tensile testing) are currently missing. Suggestions for future HEA efforts are given.
Population Dynamics of Lepidoptera Pests in Eucalyptus urophylla Plantations in the Brazilian Amazonia
Authors: Zanuncio José , Lemes Pedro , Santos Germi , Soares Marcus , Wilcken Carlos , Serrão José
Published: January 2014

Forestry companies study the population dynamics of insect pests in Integrated Pest Management for cost effectiveness. The objective of this study was to obtain qualitative and quantitative information on population fluctuation of the Lepidopteran defoliators of Eucalyptus urophylla plants in the Brazilian Amazon rainforest. In all, 402 species were collected, of which 10 were primary pests, nine were secondary pests, and the remaining bore no definite relevance to eucalyptus. Primary pests formed a low percentage of the total species, although they recorded a high percentage of the total number of individuals. The abundance of secondary pests, except in Caracuru, was less than 150 specimens annually. Primary pests showed higher population peaks during periods of low precipitation. The small number of species and the high abundance of primary and secondary pests could be due to the availability of food, or a deficiency in natural biological control. This suggests the possibilities of population outbreaks in the eucalyptus plantations. The period of highest occurrence for insect species in these crops must be identified so that suitable strategies can be developed for Integrated Pest Management.
Geospatial Interpolation and Mapping of Tropospheric Ozone Pollution Using Geostatistics
Authors: Kethireddy Swatantra , Tchounwou Paul , Ahmad Hafiz , Yerramilli Anjaneyulu , Young John
Published: January 2014

Tropospheric ozone (O3) pollution is a major problem worldwide, including in the United States of America (USA), particularly during the summer months. Ozone oxidative capacity and its impact on human health have attracted the attention of the scientific community. In the USA, sparse spatial observations for O3 may not provide a reliable source of data over a geo-environmental region. Geostatistical Analyst in ArcGIS has the capability to interpolate values in unmonitored geo-spaces of interest. In this study of eastern Texas O3 pollution, hourly episodes for spring and summer 2012 were selectively identified. To visualize the O3 distribution, geostatistical techniques were employed in ArcMap. Using ordinary Kriging, geostatistical layers of O3 for all the studied hours were predicted and mapped at a spatial resolution of 1 kilometer. A decent level of prediction accuracy was achieved and was confirmed from cross-validation results. The mean prediction error was close to 0, the root mean-standardized-prediction error was close to 1, and the root mean square and average standard errors were small. O3 pollution map data can be further used in analysis and modeling studies. Kriging results and O3 decadal trends indicate that the populace in Houston-Sugar Land-Baytown, Dallas-Fort Worth-Arlington, Beaumont-Port Arthur, San Antonio, and Longview are repeatedly exposed to high levels of O3-related pollution, and are prone to the corresponding respiratory and cardiovascular health effects. Optimization of the monitoring network proves to be an added advantage for the accurate prediction of exposure levels.
Ninth International Symposium on Recent Advances in Environmental Health Research
Authors: Tchounwou Paul
Published: January 2014

This special issue of International Journal of Environmental Research and Public Health is dedicated to the publication of selected papers presented at the Eighth International Symposium on Recent Advances in Environmental Health Research. The Symposium was organized by Jackson State University (JSU) from 16–19 September, 2012 at the Marriott Hotel in Jackson, Mississippi, USA. It was built upon the overwhelming success of seven previous symposia hosted by JSU. [...]
The Effect of Radiation on the Immune Response to Cancers
Authors: Park Bonggoo , Yee Cassian , Lee Kyung-Mi
Published: January 2014

In cancer patients undergoing radiation therapy, the beneficial effects of radiation can extend beyond direct cytotoxicity to tumor cells. Delivery of localized radiation to tumors often leads to systemic responses at distant sites, a phenomenon known as the abscopal effect which has been attributed to the induction and enhancement of the endogenous anti-tumor innate and adaptive immune response. The mechanisms surrounding the abscopal effect are diverse and include trafficking of lymphocytes into the tumor microenvironment, enhanced tumor recognition and killing via up-regulation of tumor antigens and antigen presenting machinery and, induction of positive immunomodulatory pathways. Here, we discuss potential mechanisms of radiation-induced enhancement of the anti-tumor response through its effect on the host immune system and explore potential combinational immune-based strategies such as adoptive cellular therapy using ex vivo expanded NK and T cells as a means of delivering a potent effector population in the context of radiation-enhanced anti-tumor immune environment.
Thermo-Plasmonics for Localized Graphitization and Welding of Polymeric Nanofibers
Authors: Zillohu Ahnaf , Alissawi Nisreen , Abdelaziz Ramzy , Elbahri Mady
Published: January 2014

There is a growing interest in modulating the temperature under the illumination of light. As a heat source, metal nanoparticles (NPs) have played an important role to pave the way for a new branch of plasmonics, i.e., thermo-plasmonics. While thermo-plasmonics have been well established in photo-thermal therapy, it has received comparatively less attention in materials science and chemistry. Here, we demonstrate the first proof of concept experiment of local chemistry and graphitization of metalized polymeric nanofibers through thermo-plasmonic effect. In particular, by tuning the plasmonic absorption of the nanohybrid through a change in the thickness of the deposited silver film on the fibers, the thermo-plasmonic effect can be adjusted in such a way that high enough temperature is generated enabling local welding and graphitization of the polymeric nanofibers.
Optimization of ERK Activity Biosensors for both Ratiometric and Lifetime FRET Measurements
Authors: Vandame Pauline , Spriet Corentin , Riquet Franck , Trinel Dave , Cailliau-Maggio Katia , Bodart Jean-François
Published: January 2014

Among biosensors, genetically-encoded FRET-based biosensors are widely used to localize and measure enzymatic activities. Kinases activities are of particular interest as their spatiotemporal regulation has become crucial for the deep understanding of cell fate decisions. This is especially the case for ERK, whose activity is a key node in signal transduction pathways and can direct the cell into various processes. There is a constant need for better tools to analyze kinases in vivo, and to detect even the slightest variations of their activities. Here we report the optimization of the previous ERK activity reporters, EKAR and EKAREV. Those tools are constituted by two fluorophores adapted for FRET experiments, which are flanking a specific substrate of ERK, and a domain able to recognize and bind this substrate when phosphorylated. The latter phosphorylation allows a conformational change of the biosensor and thus a FRET signal. We improved those biosensors with modifications of: (i) fluorophores and (ii) linkers between substrate and binding domain, resulting in new versions that exhibit broader dynamic ranges upon EGF stimulation when FRET experiments are carried out by fluorescence lifetime and ratiometric measurements. Herein, we characterize those new biosensors and discuss their observed differences that depend on their fluorescence properties.
A Methodology to Assess the Accuracy with which Remote Data Characterize a Specific Surface, as a Function of Full Width at Half Maximum (FWHM): Application to Three Italian Coastal Waters
Authors: Cavalli Rosa , Betti Mattia , Campanelli Alessandra , Cicco Annalisa , Guglietta Daniela , Penna Pierluigi , Piermattei Viviana
Published: January 2014

This methodology assesses the accuracy with which remote data characterizes a surface, as a function of Full Width at Half Maximum (FWHM). The purpose is to identify the best remote data that improves the characterization of a surface, evaluating the number of bands in the spectral range. The first step creates an accurate dataset of remote simulated data, using in situ hyperspectral reflectances. The second step evaluates the capability of remote simulated data to characterize this surface. The spectral similarity measurements, which are obtained using classifiers, provide this capability. The third step examines the precision of this capability. The assumption is that in situ hyperspectral reflectances are considered the “real” reflectances. They are resized with the same spectral range of the remote data. The spectral similarity measurements which are obtained from “real” resized reflectances, are considered “real” measurements. Therefore, the quantity and magnitude of “errors” (i.e., differences between spectral similarity measurements obtained from “real” resized reflectances and from remote data) provide the accuracy as a function of FWHM. This methodology was applied to evaluate the accuracy with which CHRIS-mode1, CHRIS-mode2, Landsat5-TM, MIVIS and PRISMA data characterize three coastal waters. Their mean values of uncertainty are 1.59%, 3.79%, 7.75%, 3.15% and 1.18%, respectively.
An Experimental Study on the Effect of Temperature on Piezoelectric Sensors for Impedance-Based Structural Health Monitoring
Authors: Baptista Fabricio , Budoya Danilo , Almeida Vinicius , Ulson Jose
Published: January 2014

The electromechanical impedance (EMI) technique is considered to be one of the most promising methods for developing structural health monitoring (SHM) systems. This technique is simple to implement and uses small and inexpensive piezoelectric sensors. However, practical problems have hindered its application to real-world structures, and temperature effects have been cited in the literature as critical problems. In this paper, we present an experimental study of the effect of temperature on the electrical impedance of the piezoelectric sensors used in the EMI technique. We used 5H PZT (lead zirconate titanate) ceramic sensors, which are commonly used in the EMI technique. The experimental results showed that the temperature effects were strongly frequency-dependent, which may motivate future research in the SHM field.
The Unsustainable City
Authors: Berger Matthias
Published: January 2014

“Make cities more sustainable” is an omnipresent slogan in architecture and urban planning. This article is a discussion on theoretical and practical boundaries of using the expression “sustainability” with respect to the scientific community, therefore avoiding sustainability becoming a euphemism for “doing good”. By definition, it can be concluded, cities developed as counterparts to the hinterland and, therefore, they axiomatically should be and are as a matter of fact unsustainable. Furthermore, sustainability is a binary, not a gradual concept. Something is either sustainable or not. Aiming to increase the sustainability is consequently a sham battle. It would be necessary to change our perception to acknowledge that cities should be unsustainable in order to become efficient, seen from a global perspective including the hinterland.
ANALYSIS OF ENERGY CONSUMPTION IN RENOVATED BUILDINGS AND SIMULATION OF THE PAYBACK PERIOD / ATNAUJINTŲ PASTATŲ ENERGIJOS SUVARTOJIMO ANALIZĖ IR ATSIPERKAMUMO MODELIAVIMAS
Authors: Ruzgys Audrius , Volvačiovas Robertas , Ignatavičius Česlovas
Published: January 2014

The renovation of old buildings is essential for the efficient useof energy. Improvement in the thermal characteristics of thebuilding envelope makes a significant effect on energy savings.For assessing the real impact on buildings, energy efficiencyof various measures applied in renovation is one of the mostimportant problems. Actual energy savings significantly differfrom those calculated according to the methodology described intechnical documents. The article analyses 8 renovated buildings.Three main external elements, including walls, windows androofs, in all buildings were retrofitted. Using theoretical energysavings through each element and knowing the actual savingsof the building, actual energy savings through each element arefound. Theoretical energy savings for heating after renovation,in every case, are bigger than actual energy consumption forheating before renovation. There is a big difference betweentheoretical and actual savings after renovation, sometimes up to2 times. The paper describes dependency between the envelopearea of buildings and the mismatch factor of theoretical andactual consumption. The payback period of renovated buildingsis calculated using theoretical and actual data. The theoreticalpayback period of renovation is up to 2 times shorter than theactual one. The calculation method for the estimation of the actualpayback period using the mismatch factor has been proposed,and the model of the building has been made to calculate itsprobable payback period.

Santrauka

Senų pastatų atnaujinimas būtinas norint efektyviai vartoti šilumos energiją. Šiam tikslui pasiekti reikia pagerinti tokių pastatų išorinių atitvarų termoizoliacines charakteristikas. Atnaujinant senus pastatus, vienas iš svarbiausių uždavinių – nustatyti, kokį efektą pastatų energiniam efektyvumui suteiks taikomos atnaujinimo priemonės. Metodikos, skirtos išorinių pastato atitvarų atnaujinimo poveikio energiniam efektyvumui nustatyti, pateikiamos galiojančiuose statybos techniniuose reglamentuose. Tačiau susiduriama su problema lyginant teorinius pastatų energijos sutaupymo atvejus su faktiniais, nes gaunami dideli skirtumai tarp jų. Straipsnyje pateikiama aštuonių atnaujintų namų Vilniuje ir Šiauliuose faktinio energijos suvartojimo patalpoms šildyti prieš ir po atnaujinimo analizė, gauti rezultatai palyginami su teoriniais skaičiavimais. Palyginamas tiriamų pastatų atnaujinimo atsipirkimo laikotarpis, apskaičiuotas pagal teorinius ir faktinius duomenis. Sukuriamas pastato modelis ir, įvertinant paklaidą tarp teorinių ir faktinių energijos sutaupymo atvejų, apskaičiuojamas jo atnaujinimo atsipirkimo laikotarpis bei pateikiamos išvados.
THE RESULTS OF CORELATION BETWEEN CONE TIP RESISTANCE, PUSH-IN PRESSURE LOAD CELLS AND A COMPRESSION DEVICE / KŪGINIO STIPRIO IR GILIOJO SPRAUSTINIO PAMATO PAGRINDO LAIKOMOSIOS GALIOS BANDYMU, TAIP PAT KITAIS METODAIS NUSTATYTŲ DEFORMACIJŲ MODULIŲ PRIKLAU
Authors: Statkus Tautvydas , Martinkus Vaidas
Published: January 2014

The article is aimed at identifying the correlation between soilcone resistance and soil deformation modules determined referringto the results of tested data on deep foundation bearingcapacity, the push-in pressure cell and the use of an oedometer.Physical and mechanical properties of soil have been determinedconducting laboratory and field tests. After regression analyses,the correlation between cone resistance and different kinds ofsoil deformation modules have been given. The results of theexperimental study can be used for predicting a practical approachto deep foundation in cohesionless soil.

Santrauka

Šio straipsnio tikslas yra nustatyti priklausomybes tarp grunto kūginio stiprio ir grunto deformacijų modulių, gautų iš giliojo pamato pagrindo laikomosios galios bandymų duomenų, taip pat grunto tyrimo įspraudžiamaisiais horizontaliojo slėgio matuokliais bei kompresiniu aparatu. Straipsnyje pateiktos tiriamojo orasausio smėlinio grunto fizinės ir mechaninės savybės nustatytos laboratoriniais ir lauko tyrimo metodais. Atlikus regresinę bandymų duomenų analizę straipsnio išvadose pateiktos minėtų dydžių priklausomybės. Tyrimo duomenys gali būti panaudoti sudarant praktinį metodą giliųjų spraustinių pamatų smėlinių pagrindų nuosėdžiams prognozuoti.
PARTICULARITIES OF AUTOMATED TRAFFIC CONTROL SYSTEMS IN THE CITIES OF UKRAINE
Authors: Stepanchuk A. , Bieliatynskyi A. , Pylypenko A.
Published: January 2014

The article considers the basic concepts concerningthe possibility of increasing the efficiency and capacity of theroad traffic network in the cities of Ukraine. The paper alsoanalyzes some of the measures to improve road traffic managementthrough the further development of an automated trafficcontrol system.
Analysis of geological ochre: its geochemistry, use, and exchange in the US Northern Great Plains
Authors: Kingery-Schwartz Anne , Popelka-Filcoff Rachel S. , Lopez David A. , Pottier Fabien , Hill Patrick , Glascock Michael
Published: January 2014

Samples of pigments indigenous to the US Northern Great Plains were collected in association with the conservation of a buffalo hide tanned and painted by a Crow Indian(s) in the 19th century, which is now in the collection of the National Museum of American Indian. The pigments were characterised using a series of analytical techniques – some common and others uncommon to the conservation science field, including portable X-ray fluorescence (pXRF), X-ray diffraction (XRD), and instrumental neutron activation analysis (INAA). XRF is not capable of differentiating between various ochre samples due to high detection limits. XRD can detect some matrix minerals in each sample, but these data cannot characterise pigments by original source location. INAA is capable of characterizing ochres from different sources based on trace element geochemistry; however, the large sample size it requires (approximately 100 mg), makes sampling from objects challenging and therefore makes it difficult to use for technical art history studies that focus on museum objects. INAA is useful if applied to reference materials, such as historic pigments or known sources for historic artistic materials.
Sober-living houses and changes in the personal networks of individuals in recovery
Authors: Mueller David G. , Jason Leonard A.
Published: January 2014

Social networks are an important source of support for many people in recovery from alcohol abuse. The present study investigated the role of one particular source of support for recovery in changing the personal networks of people in recovery, sober-living houses. In a randomized, longitudinal design changes in the network size, heterogeneity, and composition of usual aftercare and sober-living home residents were examined. Beneficial changes were found, such as increases in the number of recovering alcoholics and overall network size among sober-living home residents, particularly those who stayed six months or longer. Networks also became more homogeneous with respect to non-drinking among residents. The importance of changes in networks is discussed as well as the need for network-level analyses of personal recovery networks.
Translational research in neuroanaesthesia
Authors: Umamaheswara Rao Ganne
Published: January 2014

Translational research in anaesthesia provided great solutions to medicine, well beyond its scope, in the past. Exciting opportunities exist for neuroanaesthesiologists to conduct translational research not just in anaesthesia alone but in the wider realm of neurosciences. This research is expected to provide solutions to clinical neuroscience questions and to help understand some of the complex neurocognitive functions. Despite several technical developments, progress in translational sciences has been rather slow in the recent years. Re-orientation of the research programmes to a translational format with the involvement of all the stakeholders is likely to conserve the cost and provide rapid solutions to the healthcare.
A Novel Iterative-Learner Simulation Model: Fellows as Teachers
Authors: Tofil Nancy M. , Peterson Dawn Taylor , Harrington Kathy F. , Perrin Brian T. , Hughes Tyler , Zinkan J. Lynn , Youngblood Amber Q. , Bartolucci Al , White Marjorie Lee
Published: January 2014

Background

Simulation is an effective method for teaching clinical skills but has not been widely adopted to educate trainees about how to teach.

Objective

We evaluated a curriculum for pediatrics fellows by using high-fidelity simulation (mannequin with vital signs) to improve pedagogical skills.

Intervention

The intervention included a lecture on adult learning and active-learning techniques, development of a case from the fellows' subspecialties, and teaching the case to residents and medical students. Teaching was observed by an educator using a standardized checklist. Learners evaluated fellows' teaching by using a structured evaluation tool; learner evaluations and the observer checklist formed the basis for written feedback. Changes in fellows' pedagogic knowledge, attitudes, and self-reported skills were analyzed by using Friedman and Wilcoxon rank-sum test at baseline, immediate postintervention, and 6-month follow-up.

Results

Forty fellows participated. Fellows' self-ratings significantly improved from baseline to 6-month follow-up for development of learning objectives, effectively reinforcing performance, using teaching techniques to promote critical thinking, providing constructive feedback, and using case studies to teach general rules. Fellows significantly increased agreement with the statement “providing background and context is important” (4.12 to 4.44, P  =  .02).

Conclusions

Simulation was an effective means of educating fellows about teaching, with fellows' attitudes and self-rated confidence improving after participation but returning to baseline at the 6-month assessment. The simulation identified common weaknesses of fellows as teachers, including failure to provide objectives to learners, failure to provide a summary of key learning points, and lack of inclusion of all learners.
Near-surface meteorology during the Arctic Summer Cloud Ocean Study (ASCOS): evaluation of reanalyses and global climate models
Authors: de Boer G. , Shupe M. D. , Caldwell P. M. , Bauer S. E. , Persson O. , Boyle J. S. , Kelley M. , Klein S. A. , Tjernström M.
Published: January 2014

Abstract. Atmospheric measurements from the Arctic Summer Cloud Ocean Study (ASCOS) are used to evaluate the performance of three atmospheric reanalyses (European Centre for Medium Range Weather Forecasting (ECMWF)-Interim reanalysis, National Center for Environmental Prediction (NCEP)-National Center for Atmospheric Research (NCAR) reanalysis, and NCEP-DOE (Department of Energy) reanalysis) and two global climate models (CAM5 (Community Atmosphere Model 5) and NASA GISS (Goddard Institute for Space Studies) ModelE2) in simulation of the high Arctic environment. Quantities analyzed include near surface meteorological variables such as temperature, pressure, humidity and winds, surface-based estimates of cloud and precipitation properties, the surface energy budget, and lower atmospheric temperature structure. In general, the models perform well in simulating large-scale dynamical quantities such as pressure and winds. Near-surface temperature and lower atmospheric stability, along with surface energy budget terms, are not as well represented due largely to errors in simulation of cloud occurrence, phase and altitude. Additionally, a development version of CAM5, which features improved handling of cloud macro physics, has demonstrated to improve simulation of cloud properties and liquid water amount. The ASCOS period additionally provides an excellent example of the benefits gained by evaluating individual budget terms, rather than simply evaluating the net end product, with large compensating errors between individual surface energy budget terms that result in the best net energy budget.
Variations of ground-level O3 and its precursors in Beijing in summertime between 2005 and 2011
Authors: Zhang Q. , Yuan B. , Shao M. , Wang X. , Lu S. , Lu K. , Wang M. , Chen L. , Chang C. , Liu S.
Published: January 2014

Abstract. Increased levels of ground-level ozone (O3), reflecting the oxidative capacity of the atmosphere, are of increasing concern. High levels of total oxidants (Ox = O3 + NO2) have been persistently observed as a feature of Beijing's air pollution. Beijing is a typical global mega-city requiring the enforcement of stringent air quality controls as rapid economic growth continues. To evaluate the effect of air quality controls in recent years, ground-based on-line measurements at an urban site were conducted in summer and the variations in O3 with simultaneous changes in NOx and volatile organic compounds (VOCs) between 2005 and 2011 were analyzed. Both NOx and anthropogenic VOCs in Beijing decreased over the study period, 1.4 ppbv yr−1 and 1.6 ppbv yr−1 respectively, the VOCs reactivity, in term of OH loss rate showed an indistinct statistical trend due to the large contribution from naturally emitted isoprene. Meanwhile, the daytime average O3 concentrations increased significantly at an annual rate 2.6 ppbv yr−1, around 5% yr−1 between 2005 and 2011. Considering the influence of NO titration effect and the increasing in regional background in the North China Plain (NCP), the main reason for such an increase in oxidants was local photochemistry. A simplified model was used to evaluate the effect of changes in the levels of ozone precursors on ozone production, we found that between 2001 and 2006, the production rate of total oxidants, P(Ox) increased rapidly due to increased VOC levels and decreasing of NO2, while from 2006 to2011, P(Ox) remained high though, decreased slightly as a~consequence of the decrease in both VOC reactivity (5% yr−1) and NOx (4% yr−1). Measurements have shown that the air pollution control efforts of Beijing city were effective in cutting ozone precursors, but even led to higher ground-level ozone. Therefore, putting ozone as the target for air quality, a faster reduction of VOCs, especially the reactive VOCs, will be needed to go together with NOx emission control programs.
Online measurements of water-soluble organic acids in the gas and aerosol phase from the photooxidation of 1,3,5-trimethylbenzene
Authors: Praplan A. P. , Hegyi-Gaeggeler K. , Barmet P. , Pfaffenberger L. , Dommen J. , Baltensperger U.
Published: January 2014

Abstract. The formation of organic acids during photooxidation of 1,3,5-trimethylbenzene (TMB) was investigated with an online ion chromatography (IC) instrument coupled to a mass spectrometer (MS) at the Paul Scherrer Institute (PSI) smog chamber. Gas and aerosol phase were both sampled. Molecular formulae were attributed to twelve compounds with the help of high resolution MS data from filter extracts (two compounds in the gas phase only, two in the aerosol phase only and eight in both). Seven of those species could be identified unambiguously (each of them present in gas and aerosol phase): formic acid, acetic acid, glycolic acid, butyric acid, pyruvic acid, lactic acid and methylmaleic acid. The influence of the precursor concentration (TMB: 1200 and 600 ppbv) and of the presence of 2 ppbv of sulphur dioxide (SO2) on aerosol and gas phase products were further investigated. While the organic acid fraction present in the aerosol phase does not strongly depend on the precursor concentration (6 to 14%), the presence of SO2 reduces this amount to less than 3% for both high and low precursor concentration scenarios. The addition of acetic acid during the experiments indicated that the presence of small acids in the particle phase might not be due to partitioning effects.
Evaluating the performance of commonly used gas analysers for methane eddy covariance flux measurements: the InGOS inter-comparison field experiment
Authors: Peltola O. , Hensen A. , Helfter C. , Belelli Marchesini L. , Bosveld F. C. , van den Bulk W. C. M. , Elbers J. A. , Haapanala S. , Holst J. , Laurila T. , Lindroth A. , Nemitz E. , Röckmann T. , Vermeulen A. T. , Mammarella I.
Published: January 2014

Abstract. The performance of eight fast-response methane (CH4) gas analysers suitable for eddy covariance flux measurements were tested at a grassland site near the Cabauw tall tower (Netherlands) during June 2012. The instruments were positioned close to each other in order to minimize the effect of varying turbulent conditions. The moderate CH4 fluxes observed at the location, of the order of 25 nmol m−2 s−1, provided a suitable signal for testing the instruments' performance. Generally, all analysers tested were able to quantify the concentration fluctuations at the frequency range relevant for turbulent exchange and were able to deliver high-quality data. The tested cavity ring-down spectrometer (CRDS) instruments from Picarro, models G2311-f and G1301-f, were superior to other CH4 analysers with respect to instrumental noise. As an open-path instrument susceptible to the effects of rain, the LI-COR LI-7700 achieved lower data coverage and also required larger density corrections; however, the system is especially useful for remote sites that are restricted in power availability. In this study the open-path LI-7700 results were compromised due to a data acquisition problem in our data-logging setup. Some of the older closed-path analysers tested do not measure H2O vapour concentrations alongside CH4 (i.e. FMA1 and DLT-100 by Los Gatos Research) and this complicates data processing since the required corrections for dilution and spectroscopic interactions have to be based on external information. To overcome this issue, we used H2O mole fractions measured by other gas analysers, adjusted them with different methods and then applied them to correct the CH4 fluxes. Following this procedure we estimated a bias on the order of 0.1 g (CH4) m−2 (8% of the measured mean flux) in the processed and corrected CH4 fluxes on a monthly scale due to missing H2O concentration measurements. Finally, cumulative CH4 fluxes over 14 days from three closed-path gas analysers, G2311-f (Picarro Inc.), FGGA (Los Gatos Research) and FMA2 (Los Gatos Research), which were measuring H2O vapour concentrations in addition to CH4, agreed within 3% (355–367 mg (CH4) m−2) and were not clearly different from each other, whereas the other instruments derived total fluxes which showed small but distinct differences (±10%, 330–399 mg (CH4) m−2).
Predicting subsurface stormflow response of a forested hillslope – the role of connected flow paths
Authors: Wienhöfer J. , Zehe E.
Published: January 2014

Abstract. Rapid flow processes in connected preferential flow paths are widely accepted to play a key role in the rainfall–runoff response at the hillslope scale, but a quantitative description of these processes is still a major challenge in hydrological research. This paper investigates the approach of incorporating preferential flow paths explicitly in a process-based model for modelling water flow and solute transport at a steep forested hillslope. We conceptualise preferential flow paths as spatially explicit structures with high conductivity and low retention capacity, and evaluate simulations with different combinations of vertical and lateral flow paths in conjunction with variable or constant soil depths against measured discharge and tracer breakthrough. Out of 122 tested realisations, six set-ups fulfilled our selection criteria for the water flow simulation. These set-ups successfully simulated infiltration, vertical and lateral subsurface flow in structures, and allowed predicting the magnitude, dynamics and water balance of the hydrological response of the hillslope during successive periods of steady-state sprinkling on selected plots and intermittent rainfall on the entire hillslope area. The number of equifinal model set-ups was further reduced by the results of solute transport simulations. Two of the six acceptable model set-ups matched the shape of the observed breakthrough curve well, indicating that macrodispersion induced by preferential flow was captured well by the topology of the preferential flow network. The configurations of successful model set-ups suggest that preferential flow related to connected vertical and lateral flow paths is a first-order control on the hydrology of the study hillslope, whereas spatial variability of soil depth is secondary especially when lateral flow paths are present. Virtual experiments for investigating hillslope controls on subsurface processes should thus consider the effect of distinctive flow paths within the soil mantle. The explicit representation of flow paths in a hydrological process model was found to be a suitable approach for this purpose.
Estimating root zone soil moisture using near-surface observations from SMOS
Authors: Ford T. W. , Harris E. , Quiring S. M.
Published: January 2014

Abstract. Satellite-derived soil moisture provides more spatially and temporally extensive data than in situ observations. However, satellites can only measure water in the top few centimeters of the soil. Root zone soil moisture is more important, particularly in vegetated regions. Therefore estimates of root zone soil moisture must be inferred from near-surface soil moisture retrievals. The accuracy of this inference is contingent on the relationship between soil moisture in the near-surface and the soil moisture at greater depths. This study uses cross correlation analysis to quantify the association between near-surface and root zone soil moisture using in situ data from the United States Great Plains. Our analysis demonstrates that there is generally a strong relationship between near-surface (5–10 cm) and root zone (25–60 cm) soil moisture. An exponential decay filter is used to estimate root zone soil moisture using near-surface soil moisture derived from the Soil Moisture and Ocean Salinity (SMOS) satellite. Root zone soil moisture derived from SMOS surface retrievals is compared to in situ soil moisture observations in the United States Great Plains. The SMOS-based root zone soil moisture had a mean R2 of 0.57 and a mean Nash–Sutcliffe score of 0.61 based on 33 stations in Oklahoma. In Nebraska, the SMOS-based root zone soil moisture had a mean R2 of 0.24 and a mean Nash–Sutcliffe score of 0.22 based on 22 stations. Although the performance of the exponential filter method varies over space and time, we conclude that it is a useful approach for estimating root zone soil moisture from SMOS surface retrievals.
The land-ice contribution to 21st century dynamic sea-level rise
Authors: Howard T. , Ridley J. , Pardaens A. K. , Hurkmans R. T. W. L. , Payne A. J. , Giesen R. H. , Lowe J. A. , Bamber J. L. , Edwards T. L. , Oerlemans J.
Published: January 2014

Abstract. Climate change has the potential to locally influence mean sea level through a number of processes including (but not limited to) thermal expansion of the oceans and enhanced land ice melt. These lead to departures from the global mean sea level change, due to spatial variations in the change of water density and transport, which are termed dynamic sea level changes. In this study we present regional patterns of sea-level change projected by a global coupled atmosphere–ocean climate model forced by projected ice-melt fluxes from three sources: the Antarctic ice sheet, the Greenland ice sheet and small glaciers and ice caps. The largest ice melt flux we consider is equivalent to almost 0.7 m of global sea level rise over the 21st century. Since the ice melt is not constant, the evolution of the dynamic sea level changes is analysed. We find that the dynamic sea level change associated with the ice melt is small, with the largest changes, occurring in the North Atlantic, contributing of order 3 cm above the global mean rise. Furthermore, the dynamic sea level change associated with the ice melt is similar regardless of whether the simulated ice fluxes are applied to a simulation with fixed or changing atmospheric CO2.
Impact of physical properties and accumulation rate on pore close-off in layered firn
Authors: Gregory S. A. , Albert M. R. , Baker I.
Published: January 2014

Abstract. Investigations into the physical characteristics of deep firn near the lock-in zone through pore close-off are needed to improve understanding of ice core records of past atmospheric composition. Specifically, the permeability and microstructure profiles of the firn through the diffusive column influence the entrapment of air into bubbles and thus the ice age–gas age difference. The purpose of this study is to examine the nature of pore closure processes at two polar sites with very different local temperatures and accumulation rates. Density, permeability, and microstructure measurements were made on firn cores from the West Antarctic Ice Sheet (WAIS) Divide, a site that has moderate accumulation rates with a seasonal climate archive, and Megadunes in East Antarctica, a site that is a natural laboratory for accumulation rate effects in the cold low-accumulation desert. We found that the open pore structure plays a more important role than density in predicting gas transport properties, throughout the porous firn matrix. For firn below 50 m depth at both WAIS Divide and Megadunes, finer-grained layers experience close-off shallower in the firn column than do coarser-grained layers, regardless of which grain size layer is the denser layer at depth. Pore close-off occurs at a critical open porosity that is accumulation rate dependent. Defining pore close-off at a critical open porosity for a given accumulation rate as opposed to a critical total porosity accounts for the pore space available for gas transport. Below the critical open porosity, the firn becomes impermeable despite having small amounts of interconnected pore space. The low-accumulation sites, with generally coarse grains, close off at lower open porosities (~<10%) than the open porosity (~>10%) of high-accumulation sites that have generally finer grains. The microstructure and permeability even near the bottom of the firn column are relic indicators of the nature of accumulation when that firn was at the surface. The physical structure and layering are the primary controlling factors on pore close-off. In contrast to current assumptions for polar firn, the depth and length of the lock-in zone is primarily dependent upon accumulation rate and microstructural variability due to differences in grain size and pore structure, rather than the density variability of the layers.
A spurious jump in the satellite record: is Antarctic sea ice really expanding?
Authors: Eisenman I. , Meier W. N. , Norris J. R.
Published: January 2014

Abstract. Recent estimates indicate that the Antarctic sea ice cover is expanding at a statistically significant rate with a magnitude one third as large as the rapid rate of sea ice retreat in the Arctic. However, during the mid-2000s, with several fewer years in the observational record, the trend in Antarctic sea ice extent was reported to be considerably smaller and statistically indistinguishable from zero. Here, we show that the increase in the reported trend occurred primarily due to the effect of a previously undocumented change in the way the satellite sea ice observations are processed for the widely-used Bootstrap algorithm dataset, rather than a physical increase in the rate of ice advance. Although our analysis does not definitively identify whether this undocumented change introduced an error or removed one, the resulting difference in the trends suggests that a substantial error exists in either the current dataset or the version that was used prior to the mid-2000s, and numerous studies that have relied on these observations should be reexamined to determine the sensitivity of their results to this change in the dataset. Furthermore, a number of recent studies have investigated physical mechanisms for the observed expansion of the Antarctic sea ice cover. The results of this analysis raise the possibility that this expansion may be a spurious artifact of an error in the satellite observations, and that the actual Antarctic sea ice cover may not be expanding at all.