bluuebunny/crossref_metadata_2025 huggingface dataset:
Airborne hydrogen cyanide measurements using a chemical ionisation mass spectrometer for the plume identification of biomass burning forest fires
Authors: Le Breton M. , Bacak A. , Muller J. B. A. , O'Shea S. J. , Xiao P. , Ashfold M. N. R. , Cooke M. C. , Batt R. , Shallcross D. E. , Oram D. E. , Forster G. , Bauguitte S. J.-B. , Palmer P. I. , Parrington M. , Lewis A. C. , Lee J. D. , Percival C. J.
Published: September 2013

Abstract. A chemical ionisation mass spectrometer (CIMS) was developed for measuring hydrogen cyanide (HCN) from biomass burning events in Canada using I− reagent ions on board the FAAM BAe-146 research aircraft during the BORTAS campaign in 2011. The ionisation scheme enabled highly sensitive measurements at 1 Hz frequency through biomass burning plumes in the troposphere. A strong correlation between the HCN, carbon monoxide (CO) and acetonitrile (CH3CN) was observed, indicating the potential of HCN as a biomass burning (BB) marker. A plume was defined as being 6 standard deviations above background for the flights. This method was compared with a number of alternative plume-defining techniques employing CO and CH3CN measurements. The 6-sigma technique produced the highest R2 values for correlations with CO. A normalised excess mixing ratio (NEMR) of 3.68 ± 0.149 pptv ppbv−1 was calculated, which is within the range quoted in previous research (Hornbrook et al., 2011). The global tropospheric model STOCHEM-CRI incorporated both the observed ratio and extreme ratios derived from other studies to generate global emission totals of HCN via biomass burning. Using the ratio derived from this work, the emission total for HCN from BB was 0.92 Tg (N) yr−1.
Aerosol loading in the Southeastern United States: reconciling surface and satellite observations
Authors: Ford B. , Heald C. L.
Published: September 2013

Abstract. We investigate the seasonality in aerosols over the Southeastern United States using observations from several satellite instruments (MODIS, MISR, CALIOP) and surface network sites (IMPROVE, SEARCH, AERONET). We find that the strong summertime enhancement in satellite-observed aerosol optical depth (AOD) (factor 2–3 enhancement over wintertime AOD) is not present in surface mass concentrations (25–55% summertime enhancement). Goldstein et al. (2009) previously attributed this seasonality in AOD to biogenic organic aerosol; however, surface observations show that organic aerosol only accounts for ∼35% of fine particulate matter (smaller than 2.5 μm in aerodynamic diameter, PM2.5) and exhibits similar seasonality to total surface PM2.5. The GEOS-Chem model generally reproduces these surface aerosol measurements, but underrepresents the AOD seasonality observed by satellites. We show that seasonal differences in water uptake cannot sufficiently explain the magnitude of AOD increase. As CALIOP profiles indicate the presence of additional aerosol in the lower troposphere (below 700 hPa), which cannot be explained by vertical mixing, we conclude that the discrepancy is due to a missing source of aerosols above the surface layer in summer.
Secondary organic aerosol production from diesel vehicle exhaust: impact of aftertreatment, fuel chemistry and driving cycle
Authors: Gordon T. D. , Presto A. A. , Nguyen N. T. , Robertson W. H. , Na K. , Sahay K. N. , Zhang M. , Maddox C. , Rieger P. , Chattopadhyay S. , Maldonado H. , Maricq M. M. , Robinson A. L.
Published: September 2013

Abstract. Environmental chamber ("smog chamber") experiments were conducted to investigate secondary organic aerosol (SOA) production from dilute emissions from two medium-duty diesel vehicles (MDDVs) and three heavy-duty diesel vehicles (HDDVs) under urban-like conditions. Some of the vehicles were equipped with emission control aftertreatment devices including diesel particulate filters (DPF), selective catalytic reduction (SCR) and diesel oxidation catalysts (DOC). Experiments were also performed with different fuels (100% biodiesel and low-, medium- or high-aromatic ultralow sulfur diesel) and driving cycles (Unified Cycle, Urban Dynamometer Driving Schedule, and creep+idle). During normal operation, vehicles with a catalyzed DPF emitted very little primary particulate matter (PM). Furthermore, photo-oxidation of dilute emissions from these vehicles produced essentially no SOA (below detection limit). However, significant primary PM emissions and SOA production were measured during active DPF regeneration experiments. Nevertheless, under reasonable assumptions about DPF regeneration frequency, the contribution of regeneration emissions to the total vehicle emissions is negligible, reducing PM trapping efficiency by less than 2%. Therefore, catalyzed DPFs appear to be very effective in reducing both primary and secondary fine particulate matter from diesel vehicles. For both MDDVs and HDDVs without aftertreatment substantial SOA formed in the smog chamber – with the emissions from some vehicles generating twice as much SOA as primary organic aerosol after three hours of oxidation at typical urban VOC : NOx ratios (3:1). Comprehensive organic gas speciation was performed on these emissions, but less than half of the measured SOA could be explained by traditional (speciated) SOA precursors. The remainder presumably originates from the large fraction (~30%) of the non-methane organic gas emissions that could not be speciated using traditional one-dimensional gas-chromatography. The unspeciated organics – likely comprising less volatile species, such as intermediate volatility organic compounds – appear to be important SOA precursors; we estimate that the effective SOA yield (defined as the ratio of SOA mass to reacted precursor mass) was 9 ± 6% if both speciated SOA precursors and unspeciated organics are included in the analysis. SOA production from creep+idle operation was 3–4 times larger than SOA production from the same vehicle operated over the Urban Dynamometer Driving Schedule (UDDS). Fuel properties had little or no effect on primary PM emissions or SOA formation.
Primary to secondary organic aerosol: evolution of organic emissions from mobile combustion sources
Authors: Presto A. A. , Gordon T. D. , Robinson A. L.
Published: September 2013

Abstract. A series of smog chamber experiments were conducted to investigate the transformation of primary organic aerosol (POA) and formation of secondary organic aerosol (SOA) during the photo-oxidation of dilute gasoline and diesel motor vehicle exhaust. In half of the experiments POA was present in the chamber at the onset of photo-oxidation. In these experiments positive matrix factorization (PMF) was used to determine separate POA and SOA factors from aerosol mass spectrometer data. A two-factor solution, with one POA factor and one SOA factor, was sufficient to describe the organic aerosol in all but one experiment. In the other half of the experiments, POA was not present at the onset of photo-oxidation; these experiments are considered "pure SOA" experiments. The POA mass spectrum was similar to the mass spectra of the hydrocarbon-like organic aerosol factor determined from ambient datasets with one exception, a diesel vehicle equipped with a diesel oxidation catalyst. The SOA in all experiments had a constant composition over the course of photo-oxidation, and did not appear to age with continued oxidation. The SOA mass spectra for the various gasoline and diesel vehicles were similar to each other, but markedly different than ambient oxidized organic aerosol factors. Van Krevelen analysis of the POA and SOA factors for gasoline and diesel experiments reveal slopes of −0.68 and −0.43, respectively. This suggests that the oxidation chemistry in these experiments is a combination of carboxylic acid and alcohol/peroxide formation, consistent with ambient oxidation chemistry. These experiments also provide insight to the mixing behavior of the POA and SOA. Analysis of the time series of the POA factor concentration and a basis-set model both indicate that for all but one of the vehicles tested here, the POA and SOA seem to mix and form a single organic aerosol phase.
Global distributions and trends of atmospheric ammonia (NH3) from IASI satellite observations
Authors: Van Damme M. , Clarisse L. , Heald C. L. , Hurtmans D. , Ngadi Y. , Clerbaux C. , Dolman A. J. , Erisman J. W. , Coheur P. F.
Published: September 2013

Abstract. Ammonia (NH3) emissions in the atmosphere have strongly increased in the past decades, largely because of the intensive livestock production and use of fertilizers. As a short-lived species, NH3 is highly variable in the atmosphere and its concentration is generally small, except in and close to local source areas. While ground-based measurements are possible, they are challenging and sparse. Advanced infrared sounders in orbit have recently demonstrated their capability to measure NH3, offering a new tool to refine global and regional budgets. In this paper we describe an improved retrieval scheme of NH3 total columns from the measurements of the Infrared Atmospheric Sounding Interferometer (IASI). It exploits the hyperspectral character of this instrument by using an extended spectral range (800–1200 cm−1) where NH3 is optically active. This scheme consists of the calculation of a dimensionless spectral index from the IASI level1C radiances, which is subsequently converted to a total NH3 column using look-up-tables built from forward radiative transfer model simulations. We show how to retrieve the NH3 total columns from IASI quasi-globally and twice daily, above both land and sea, without large computational resources and with an improved detection limit. The retrieval also provides error characterization on the retrieved columns. Five years of IASI measurements (1 November 2007 to 31 October 2012) have been processed to acquire the first global and multiple-year dataset of NH3 total columns, which are evaluated and compared to similar products from other retrieval methods. Spatial distributions from the five years dataset are provided and analyzed at global and regional scales. We show in particular the ability of this method to identify smaller emission sources than those reported previously, as well as transport patterns above sea. The five year time series is further examined in terms of seasonality and inter-annual variability (in particular as a function of fire activity) separately for the Northern and Southern Hemispheres.
Modeling the influence of precursor volatility and molecular structure on secondary organic aerosol formation using evaporated fuel experiments
Authors: Jathar S. H. , Donahue N. M. , Adams P. J. , Robinson A. L.
Published: September 2013

Abstract. We use SOA production data from an ensemble of evaporated fuels to test various SOA formation models. Except for gasoline, traditional SOA models focusing exclusively on volatile species in the fuels under-predict the observed SOA formation. These models can be improved dramatically by accounting for lower volatility species, but at the cost of a large set of free parameters. In contrast, a SOA model based only on the volatility of the precursor, starting with the volatility distribution of the evaporated fuels and optimized for the volatility reduction of first-generation products, reasonably reproduces the observed SOA formation with relatively few free parameters. The exceptions are exotic fuels such as Fischer-Tropsch fuels that expose the central assumption of the volatility based model that most emissions consist of complex mixtures displaying reasonably average behavior. However, for the vast majority of fuels, the volatility based model performs well.
Establishing the contribution of lawn mowing to atmospheric aerosol levels in American suburbs
Authors: Harvey R. M. , Zahardis J. , Petrucci G. A.
Published: September 2013

Abstract. Green leaf volatiles (GLVs) are a class of wound-induced volatile organic compounds emitted by several plant species. Turfgrasses emit a complex profile of GLVs upon mowing, as evidenced by the "freshly cut grass" smell, some of which are readily oxidized in the atmosphere to contribute to secondary organic aerosol (SOA). The contribution of lawn mowing-induced SOA production may be especially impactful at the urban/suburban interface, where urban hubs provide a source of anthropogenic oxidants and SOA while suburban neighborhoods have the potential to emit large quantities of reactive, mow-induced GLVs. This interface provides a unique opportunity to study aerosol formation in a multi-component system and at a regionally relevant scale. Freshly cut grass was collected from a study site in Essex Junction, Vermont and was placed inside a 775 L Teflon experimental chamber. Thermal desorption gas chromatography mass spectrometry (TD-GC/MS) was used to characterize the emitted GLV profile. Ozone was introduced to the experimental chamber and TD-GC/MS was used to monitor the consumption of these GLVs and the subsequent evolution of gas phase products while a scanning mobility particle sizer was used to continuously measure aerosol size distributions and mass loadings as a result of grass clipping ozonolysis. Freshly cut grass found to emit a complex mixture of GLVs, dominated by cis-3-hexenyl acetate and cis-3-hexenol, which were released at an initial rate of 1.8 (±0.5) μg and 0.07 (±0.03) μg per square meter of lawn mowed with each mowing. Chamber studies using pure standards of cis-3-hexenyl acetate (CHA) and cis-3-hexenol (HXL) were found to have aerosol yields of 1.2 (±1.1)% and 3.3 (±3.1)%, respectively. Using these aerosol yields and the emission rate of these CHA and HXL by grass, SOA evolution by ozonolysis of grass clippings was predicted. However, the measured SOA mass produced from the ozonolysis of grass clippings exceeded the predicted amount, by upwards of ~ 150%. The ozonolysis of a mixture of CHA and HXL representative of environmental mixing ratios also failed to accurately model the SOA mass produced by grass clippings. Aerial photographs and geospatial analysis were used to determine the turfgrass coverage in a suburban neighborhood, which was then used along with measured SOA production as a function of grass mowed to determine that lawn mowing has the potential to contribute 47 μg m−2 SOA to the atmosphere per mowing event by ozonolysis, which cannot be modeled solely by the ozonolysis of CHA, HXL or a representative mixture of the two.
Comparison of AOD between CALIPSO and MODIS: significant differences over major dust and biomass burning regions
Authors: Ma X. , Bartlett K. , Harmon K. , Yu F.
Published: September 2013

Abstract. Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) provide global vertical profiles of aerosol optical properties for the first time. In this study, we employed about 6 yr (2006–2011) of CALIPSO level 3 monthly mean gridded aerosol optical depth (AOD) products (daytime and nighttime) for cloud-free conditions, to compare with the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra/Aqua level 3 monthly mean AOD dataset for the same time period. While the spatial distribution and seasonal variability of CALIPSO AOD is generally consistent with that of MODIS, CALIPSO is overall lower than MODIS as MODIS has higher frequency than CALIPSO for most bins of AOD. The correlation between MODIS and CALIPSO is better over ocean than over land. We focused on four regions that have large systematic differences: two over dust regions (the Sahara and Northwest China) and two over biomass burning regions (South Africa and South America). It is found that CALIPSO AOD is significantly lower than MODIS AOD over dust regions during the whole time period, with a maximum difference of 0.3 over the Saharan region and 0.25 over Northwest China. For biomass burning regions, CALIPSO AOD is significantly higher than MODIS AOD over South Africa, with a maximum difference of 0.25. Additionally CALIPSO AOD is slightly higher than MODIS AOD over South America for most of the time period, with a few exceptions in 2006, 2007, and 2010, when biomass burning is significantly stronger than during other years. We analyzed the impact of the satellite spatial and temporal sampling issue by using level 2 CALIPSO and MODIS products, and these systematic differences can still be found. The results of this study indicate that systematic differences of CALIPSO relative to MODIS are closely associated with aerosol types, which vary by location and season. Large differences over dust and biomass burning regions may suggest that assumptions made in satellite retrievals, such as the assumed lidar ratios for CALIPSO retrievals over dust and biomass burning regions or the surface reflectance information and/or the aerosol model utilized by the MODIS algorithm, are not appropriate.
Timing of sea ice retreat can alter phytoplankton community structure in the western Arctic Ocean
Authors: Fujiwara A. , Hirawake T. , Suzuki K. , Imai I. , Saitoh S.-I.
Published: September 2013

Abstract. This study assesses the response of phytoplankton assemblages to recent climate change, especially with regard to the shrinking of sea ice in the northern Chukchi Sea of the western Arctic Ocean. Distribution patterns of phytoplankton groups in the late summers of 2008–2010 were analyzed based on HPLC pigment signatures and, the following four major algal groups were inferred via multiple regression and cluster analyses: prasinophytes, diatoms, haptophytes and dinoflagellates. A remarkable interannual difference in the distribution pattern of the groups was found in the northern basin area. Haptophytes dominated and dispersed widely in warm surface waters in 2008, whereas prasinophytes dominated in cold water in 2009 and 2010. A difference in the onset date of sea ice retreat was evident among years – the sea ice retreat in 2008 was 1–2 months earlier than in 2009 and 2010. The spatial distribution of early sea ice retreat matched the areas in which a shift in algal community composition was observed. Steel-Dwass's multiple comparison tests were used to assess the physical, chemical and biological parameters of the four clusters. We found a statistically significant difference in temperature between the haptophyte-dominated cluster and the other clusters, suggesting that the change in the phytoplankton communities was related to the earlier sea ice retreat in 2008 and the corollary increase in sea surface temperatures. Longer periods of open water during the summer, which are expected in the future, may affect food webs and biogeochemical cycles in the western Arctic due to shifts in phytoplankton community structure.
The impact of nitrogen and phosphorous limitation on the estimated terrestrial carbon balance and warming of land use change over the last 156 yr
Authors: Zhang Q. , Pitman A. J. , Wang Y. P. , Dai Y. J. , Lawrence P. J.
Published: September 2013

Abstract. We examine the impact of land use and land cover change (LULCC) over the period from 1850 to 2005 using an Earth system model that incorporates nitrogen and phosphorous limitation on the terrestrial carbon cycle. We compare the estimated CO2 emissions and warming from land use change in a carbon-only version of the model with those from simulations, including nitrogen and phosphorous limitation. If we omit nutrients, our results suggest LULCC cools on the global average by about 0.1 °C. Including nutrients reduces this cooling to ~ 0.05 °C. Our results also suggest LULCC has a major impact on total land carbon over the period 1850–2005. In carbon-only simulations, the inclusion of LULCC decreases the total additional land carbon stored in 2005 from around 210 Pg C to 85 Pg C. Including nitrogen and phosphorous limitation also decreases the scale of the terrestrial carbon sink to 80 Pg C. Shown as corresponding fluxes, adding LULCC on top of the nutrient-limited simulations changes the sign of the terrestrial carbon flux from a sink to a source (12 Pg C). The CO2 emission from LULCC from 1850 to 2005 is estimated to be 130 Pg C for carbon only simulation, or 97 Pg C if nutrient limitation is accounted for in our model. The difference between these two estimates of CO2 emissions from LULCC largely results from the weaker response of photosynthesis to increased CO2 and smaller carbon pool sizes, and therefore lower carbon loss from plant and wood product carbon pools under nutrient limitation. We suggest that nutrient limitation should be accounted for in simulating the effects of LULCC on the past climate and on the past and future carbon budget.
Simplified PRBMs of spatial compliant multi-beam modules for planar motion
Authors: Hao G.
Published: September 2013

Abstract. PRBMs (pseudo-rigid-body models) have been becoming important engineering technologies/methods in the field of compliant mechanisms to simplify the design and analysis through the use of the knowledge body of rigid-body mechanisms coupling with springs. This article addresses the PRBMs of spatial multi-beam modules for planar motion, which are composed of three or more symmetrical wire/slender beams parallel to each other where the planar twisting DOF (degree of freedom) is assumed to be very small for specific applications/loading conditions. Simplified PRBMs are firstly proposed through replacing each beam in spatial multi-beam module with a rigid-body link plus two identical spherical joints at its two ends. The characteristics factor, bending stiffness and twisting stiffness for the spherical joint are determined. Load-displacement equations are then derived for a class of spatial multi-beam modules and general spatial multi-beam modules using the virtual work principle and kinematic relationships. Finally, nonlinear FEA (finite element analysis) is employed with comparisons with the PRBMs. The present PRBMs have shown the ability to predict the primary nonlinear constraint characteristics such as load-stiffening effect, cross-axis coupling in the two primary translational directions and buckling load.
The anomalous low and high temperatures of 2012 over Greece: an explanation from a meteorological and climatological perspective
Authors: Tolika K. , Maheras P. , Pytharoulis I. , Anagnostopoulou C.
Published: September 2013

Abstract. The year of 2012 is characterized, for Greece, as the hottest one in the available record dating back to 1958, presenting also the widest annual temperature range. During the summer and autumn months, numerous regions in the domain of study experienced record-breaking maximum and minimum temperatures. Conversely, the winter period was particularly cold and January was one of the coldest months in the last 55 yr. The analysis of the cold period indicates that the synoptic conditions resemble the positive phase of the Eastern Mediterranean Pattern (EMP). The predominance of these cool conditions seems to be primarily related to an intense NNW or NNE atmospheric circulation, as a consequence of the positive EMP phase. Moreover, the reduction of the floating sea ice emerged as a key driver to the formation of a low pressure pattern and the reinforcement of the trough south of Scandinavia, which in turn strengthened the Siberia High east of the trough. This reinforcement resulted in a blocking pattern and in the favorable conditions for the EMP formation The atmospheric circulation during the prolonged high-temperature period resembles, respectively, the negative phase of North Sea–Caspian Pattern teleconnection. The observed positive pole, in conjunction with the strong southwestern circulation, results in temperature increases and in the development of a smooth pressure field that contributes to the weakening of the Etesian winds and therefore to calm conditions over the continental areas.
Review of some significant claimed irregularities in Scandinavian postglacial uplift in time scales from tens to thousands of years: earthquakes?
Authors: Gregersen S.
Published: September 2013

Abstract. The postglacial uplift/subsidence in Scandinavia is regular. And the phenomenon is similar in time scales of tens, hundreds and thousands of years studied via geodesy, seismology and geology. Searches for irregularities in the form of earthquakes claimed in the scientific literature have disclosed many earthquakes right after the Ice Age and some later cases for further evaluation. In a previous report the present author has mentioned doubts about the validity of some of the most significant claimed irregularities. In the present paper a review is made of these significant claimed irregularities in the southwestern flank of the Scandinavian postglacial uplift/subsidence via literature studies of geodetic and geological claims of earthquakes as well as discussions in the field. Geodetic observations exist for all of Scandinavia. Those describe the phenomenon in 10s–100s of years scale. Earthquake observations in seismology are of relevance in the same time scales. Geological studies of dated shore lines describe the postglacial vertical earth-surface motion in a quite different time scale of 100s–1000s of years. There is a need for integration of these observations geographically. This is happening in the various time scales in the DynaQlim project. The review finds the claims improbable about the following: (1) geodynamical motion in the Copenhagen area, (2) a paleo-earthquake in Læsø and (3) the recently proposed water level discrepancy in the southern part of Denmark. The assessment is less certain, but falls to improbable concerning (4) proposed paleo-earthquakes by Hallandsåsen in southwestern Sweden.
Revegetation of abandoned copper mines: the role of seed banks and soil amendments
Authors: Carvalho A. , Nabais C. , Roiloa S. R. , Rodríguez-Echeverría S.
Published: September 2013

Abstract. Mining is one of the main causes of environmental pollution by heavy metals and (re)vegetation of mine spoils is the most effective method of preventing wind and water erosion and the consequent spread of contaminants to surrounding areas. However, plant establishment and growth are conditioned by some limiting factors of mine soils, such as low pH, low fertility, high heavy metal concentration, and a small seed bank to initiate plant establishment. Improving soil physical and chemical properties is required in many cases for successful (re)vegetation programs. In the copper mine of Touro, Galicia, Spain there is a large-scale project of soil amendment underway using technosols, a mixture of several organic residuals, to improve the conditions of mine soils. We evaluated the seed bank of several types of technosols, mine soil and soil from a control area outside the mine by studying seedling emergence in these soils. In a second experiment we evaluated the impact of increasing pH with liming and the admixing of nutrient-rich soil on the growth of two grasses (Lolium perenne and Dactylis glomerata) and two legumes (Medicago sativa and Trifolium subterrraneum) both sown individually and in mixtures. Seedling emergence and species richness were highest in the technosols. Soil amendments promoted plant growth, with the addition of high-nutrient soil being the best amendment for the four plant species tested. Plant growth was impaired in the mine soil. Lolium perenne was the only plant species that germinated and grew in this soil. We found that soil amendments, either through the addition of technosols, pH buffering or nutrient enrichment, are essential for promoting the revegetation of mine areas.
Contribuciones de Zamorano al Entendimiento de la Biodiversidad de los Artrópodos de Honduras
Authors: Schlein Oliver , Cave Ronald D.
Published: September 2013

La Colección de Artrópodos de Zamorano fue fundada hace más de 30 años y tiene más de 250,000 especímenes, los órdenes más dominantes son Coleoptera, Hymenoptera y Lepidoptera. Más de 90,000 especímenes identificados están digitalizados en su propia base de datos y han sido recolectados en más de 300 sitios, la mayoría en Honduras. Los inventarios de escarabajos de las familias Cerambycidae y Scarabaeidae y de parasitoides himenópteros son de valor científico enorme y único en toda la región. Cuatro proyectos muy influyentes, financiados por fondos externos, fueron realizados durante los primeros 25 años de la colección y están descritos con sus logros centrales: 1) inventario de los parasitoides de la mosca blanca de la batata, Bemisia tabaci (Gennadius); 2) la diversidad y biología de los escarabajos joya, Chrysina spp. (Scarabaeidae); 3) inventario de la subfamilia Dynastinae (Scarabaeidae); y 4) la capacitación de maestros, guardarecursos y guías sobre varios aspectos de la entomología. Catorce estudiantes zamoranos hicieron sus tesis en biodiversidad vinculadas con la misión de la Colección. Zamorano apoya la organización, la logística y las investigaciones entomológicas internacionales en Honduras. Además, en cooperación con fundaciones e instituciones nacionales y estatales, se investiga la biodiversidad de artrópodos en áreas protegidas de Honduras. En la gran mayoría de estas áreas, pocos o ningún dato existe sobre la fauna de artrópodos presente. Próximamente, se unirá la Colección de Artrópodos de Zamorano con otra colección importante regionalmente, el Museo Entomológico de León, Nicaragua, añadiendo otros 250,000 especímenes, en su mayoría recolectados en Nicaragua, para ser incorporados al inventario presente. Así, la colección de Zamorano contará con aproximadamente 500,000 especímenes y se convertirá en la colección más grande y representativa de Honduras y Nicaragua, y será una de las colecciones más grandes e importantes de Centroamérica.DOI: http://dx.doi.org/10.5377/ceiba.v52i1.1036
Setenta Años de contribuciones de la Escuela Agrícola Panamericana a la Protección de los Suelos
Authors: Arévalo Gloria , Gauggel Carlos
Published: September 2013

La unidad de suelos de la Escuela Agrícola Panamericana, Zamorano, Honduras, ha participado desde su fundación en la formación de profesionales con excelencia académica y un conocimiento profundo y práctico de los principios de suelos y aguas, que contribuya substancialmente al incremento de la producción de alimentos, pero conservando y mejorando el medio ambiente. En el transcurso del tiempo, ha evolucionado a ser una unidad que cumple con su principal objetivo de formar profesionales y se proyecta a brindar apoyo técnico al sector agropecuario, desde pequeños productores a empresas multinacionales y entes gubernamentales, como unidad de servicio y proyección de la institución. La unidad de suelos se ha posicionado en uno de los pilares de la agricultura sostenible al usar la tecnología más avanzada, poseer un equipo técnico altamente capacitado y la participación activa de los estudiantes en todas las actividades técnicas y docentes en las que se ocupa. El Laboratorio de Suelos hace parte de la unidad de suelos y en el se realizan análisis químicos de suelos, aguas y tejido vegetal, que se ha proyectado como uno de los más confiables como respaldo de la actividad agropecuaria de los países de la región. Además, implementó una parcela demostrativa para prácticas de conservación de suelos y un club de suelos como actividades académicas y de extensión. DOI: http://dx.doi.org/10.5377/ceiba.v52i1.1129
Contribuciones del Programa de Investigaciones en Frijol en Centro América y El Caribe
Authors: Rosas Juan Carlos
Published: September 2013

El Programa de Investigaciones en Frijol (PIF) es un programa regional enfocado en el mejoramiento genético del frijol común (Phaseolus vulgaris L.) que enfatiza en la generación y diseminación de variedades mejoradas de las clases comerciales de frijol de grano rojo y negro. Su enfoque regional abarca los países de Centro América y el Caribe dónde se cultivan estos dos tipos de granos. Sus clientes principales son los pequeños productores de frijol y las organizaciones públicas y privadas involucradas en el desarrollo y transferencia de tecnologías para este cultivo básico. Los énfasis en mejoramiento genético del PIF son la resistencia a enfermedades, la tolerancia a la sequía, la baja fertilidad de los suelos y las altas temperaturas. El mejoramiento genético es realizado utilizando técnicas y métodos convencionales, mejoramiento participativo, selección asistida con marcadores, y la evaluación y validación regional a través de los programas miembros de la Red de Frijol. El PIF y sus colaboradores han liberado más de 40 variedades mejoradas de frijol ampliamente utilizadas por pequeños agricultores de Centro América y Haití, lo que representan un impacto significativo en la seguridad alimentaria y calidad de vida de las familias beneficiarias. Los colaboradores del PIF incluyen a programas nacionales, organizaciones no gubernamentales, el Centro Internacional de Agricultura Tropical, los programas Bean/Cowpea y Dry Grain Pulses CRSP, y el Programa Colaborativo de Fitomejoramiento Participativo para Mesoamérica.DOI: http://dx.doi.org/10.5377/ceiba.v52i1.967
Contribuciones de Zamorano a la Acuacultura Latinoamericana
Authors: Meyer Daniel E.
Published: September 2013

Activities in aquaculture were begun in Zamorano in 1976 with the stocking of 400 fingerlings of the Java tilapia (Tilapia mossambica, now Oreochromis mossambicus) in a pond recently constructed for this purpose. Since then Zamorano has contributed to promoting aquaculture by training persons interested in farming fish and crustaceans, developing appropriate infrastructure and through varied and frequent research and extension activities. The most significant Zamorano accomplishments in aquaculture have been to train more than 7000 persons on the fundamentals of aquaculture and the distribution of more than 10,000 copies of several technical manuals on the topics of aquaculture and culture of tilapia. Technicians from Zamorano have offered short courses on these topics in ten different countries since 1990. Research efforts in aquaculture have focused on the utilization of the hormone 17-Alpha-Methyl-Testosterone in controlling the sex of tilapia fry, developing the infrastructure and management protocols for tilapia broodstock, efficient use of feeds and feeding fish and shrimp, the adaptability of tilapia to saline and brackish water, and environmental studies.DOI: http://dx.doi.org/10.5377/ceiba.v52i1.969
Remembranzas y Reflexiones del Programa de Manejo Integrado de Plagas en Zamorano de 1980 a 1993
Authors: Andrews Keith L.
Published: September 2013

El programa de Manejo Integrado de Plagas (MIP), llevado a cabo por un equipo interdisciplinario en Zamorano desde 1980 hasta 1993, hizo importantes contribuciones al progreso científico y técnico regional, así como a la evolución institucional y programas educativos de Zamorano. El programa de MIP dejó un legado en las prácticas de manejo de plagas, en materiales didácticos y en prácticas de desarrollo rural. El programa tuvo su gran impacto porque se basó en la búsqueda abierta, la asunción de riesgos, se operó con un mínimo de interferencia del donante y la institución anfitriona, y se centró en la creatividad humana en lugar de resultados predecibles y medibles.DOI: http://dx.doi.org/10.5377/ceiba.v52i1.973
Contribuciones de la Escuela Agrícola Panamericana a la Producción Porcina
Authors: Castillo Rogel
Published: September 2013

La Escuela Agrícola Panamericana (Zamorano) en Honduras ha mejorado la porcicultura regional desde su fundación, importando cerdos puros de razas mejoradas y poniéndolos a la disposición de los productores. Ha aportado a través de sus programas de investigación aplicada en nutrición, reproducción y sistemas de producción porcina, con los Proyectos de Graduación (tesis) de sus estudiantes. En nutrición ha trabajado en cerdos destetados, buscando alternativas para mejorar la dieta en esta etapa del cerdo, que es una de las más críticas, por la transición de la dieta líquida y rica en nutrientes (leche de la cerda), a una dieta sólida y que en muchos casos no reúne las condiciones adecuadas para los lechones. Adicionalmente, se han evaluado alternativas para reducir o eliminar el uso de antibióticos en su dieta. En cerdos de crecimiento y engorde, los estudios se han enfocado en evaluar dietas que permitan la expresión del potencial genético de crecimiento de los animales y que sean económicas. En reproducción se han hecho aportes en la técnica de inseminación artificial, evaluando el uso de infusiones uterinas previo a la inseminación, evaluación de diluyentes para semen porcino, hacer más eficiente el uso de semen congelado y las técnicas de inseminación poscervical. En los sistemas de producción se han evaluado densidades poblaciones en corrales de engorde, edades de destete, la inmunocastración y se generó un sistema de información gerencial para que los pequeños y medianos productores cuenten con un sistema de manejo y análisis de registros para tomar decisiones adecuadas. A partir de 1999, se reforzó el programa de mejoramiento genético con la importación de semen congelado de Estados Unidos de las razas Duroc, Landrace y Yorkshire, generando animales de reemplazo de alto valor genético que están disponibles para los productores de la región.DOI: http://dx.doi.org/10.5377/ceiba.v52i1.975
Influence of Growing Location on the Phytochemical Content of Pecan (Carya illinoinensis) Oil
Authors: Domínguez-Avila Jesús Abraham , Alvarez-Parrilla Emilio , González-Aguilar Gustavo Adolfo , Villa-Rodríguez Jose , Olivas-Orozco Guadalupe Isela , Molina Corral Javier , Gómez-García María del Consuelo , De la Rosa Laura A.
Published: September 2013

Pecan (Carya illinoinensis) is a tree nut native to North America with high oil content. Pecan oil is rich in unsaturated fatty acids and other lipid soluble phytochemicals. Many geographical and environmental factors are responsible for the phytochemical content of the oil, and little current information exists on the properties of pecans grown in northern México. We formulated the hypothesis that pecans grown in multiple locations are exposed to different environmental conditions which alter the concentration of the phytochemicals in the oil. We characterized oil from pecans harvested in 2009 and 2010, in three different regions in northern Mexico. The content of individual fatty acids varied significantly within growing location (mainly oleic and linoleic, which were inversely related) and from year to year (mainly linolenic). Phytosterols and tocopherols also showed significant variation among locations; polyphenols were statistically similar in all samples. Oxidative stability of pecan oil, evaluated by differential scanning calorimetry, was similar to other oils with a similar content of unsaturated fatty acids. It may be concluded that the chemical composition of pecan oil is sensitive to the environment in which it is produced, but on average, the studied pecan oils were good sources of phytochemicals.
Effects of Side Walls on the Motion Induced by an Infinite Plate that Applies Shear Stresses to an Oldroyd-B Fluid
Authors: Rana Mehwish , Shahid Nazish , Zafar Azhar Ali
Published: September 2013

Unsteady motions of Oldroyd-B fluids between two parallel walls perpendicular to a plate that applies two types of shears to the fluid are studied using integral transforms. Exact solutions are obtained both for velocity and non-trivial shear stresses. They are presented in simple forms as sums of steady-state and transient solutions and can easily be particularized to give the similar solutions for Maxwell, second-grade and Newtonian fluids. Known solutions for the motion over an infinite plate, applying the same shears to the fluid, are recovered as limiting cases of general solutions. Finally, the influence of side walls on the fluid motion, the distance between walls for which their presence can be neglected, and the required time to reach the steady-state are graphically determined.
A Fast and High-Resolution Multi-Target Localization Approach in MIMO Radar
Authors: Zhang Yu , Jiang Hong , Wei Ying-Chun , Cui Hai-Jing
Published: September 2013

This paper presents a fast and high-resolution estimation approach using polarization information combined with angle information for multi-target localization in bistatic multiple-input multiple-output (MIMO) radar. The propagator method (PM) is extended to jointly estimate the direction of departure (DOD), the direction of arrival (DOA) and the polarization parameters. The PM avoids the singular value decomposition (SVD) of the covariance matrix of the received signals so that the computational complexity is reduced. In addition, the closely spaced targets can be well distinguished by polarization diversity. The Cramer-Rao bounds (CRBs) of the estimated parameters are derived. The position of a target is calculated based on the estimated angles. The simulation results demonstrate that the proposed approach can achieve better performance compared with conventional methods of target localization.
PID-Controller Tuning Optimization with Genetic Algorithms in Servo Systems
Authors: Jaen-Cuellar Arturo Y. , de J. Romero-Troncoso Rene , Morales-Velazquez Luis , Osornio-Rios Roque A.
Published: September 2013

Performance improvement is the main goal of the study of PID control and much research has been conducted for this purpose. The PID filter is implemented in almost all industrial processes because of its well-known beneficial features. In general, the whole system's performance strongly depends on the controller's efficiency and hence the tuning process plays a key role in the system's behaviour. In this work, the servo systems will be analysed, specifically the positioning control systems. Among the existent tuning methods, the Gain-Phase Margin method based on Frequency Response analysis is the most adequate for controller tuning in positioning control systems. Nevertheless, this method can be improved by integrating an optimization technique. The novelty of this work is the development of a new methodology for PID control tuning by coupling the Gain-Phase Margin method with the Genetic Algorithms in which the micro-population concept and adaptive mutation probability are applied. Simulations using a positioning system model in MATLAB and experimental tests in two CNC machines and an industrial robot are carried out in order to show the effectiveness of the proposal. The obtained results are compared with both the classical Gain-Phase Margin tuning and with a recent PID controller optimization using Genetic Algorithms based on real codification. The three methodologies are implemented using software.
Visual Trajectory-Tracking Model-Based Control for Mobile Robots
Authors: Zdešar Andrej , Škrjanc Igor , Klančar Gregor
Published: September 2013

In this paper we present a visual-control algorithm for driving a mobile robot along the reference trajectory. The configuration of the system consists of a two-wheeled differentially driven mobile robot that is observed by an overhead camera, which can be placed at arbitrary, but reasonable, inclination with respect to the ground plane. The controller must be capable of generating appropriate tangential and angular control velocities for the trajectory-tracking problem, based on the information received about the robot position obtained in the image. To be able to track the position of the robot through a sequence of images in real-time, the robot is marked with an artificial marker that can be distinguishably recognized by the image recognition subsystem.

Using the property of differential flatness, a dynamic feedback compensator can be designed for the system, thereby extending the system into a linear form. The presented control algorithm for reference tracking combines a feedforward and a feedback loop, the structure also known as a two DOF control scheme. The feedforward part should drive the system to the vicinity of the reference trajectory and the feedback part should eliminate any errors that occur due to noise and other disturbances etc. The feedforward control can never achieve accurate reference following, but this deficiency can be eliminated with the introduction of the feedback loop. The design of the model predictive control is based on the linear error model. The model predictive control is given in analytical form, so the computational burden is kept at a reasonable level for real-time implementation. The control algorithm requires that a reference trajectory is at least twice differentiable function. A suitable approach to design such a trajectory is by exploiting some useful properties of the Bernstein-Bézier parametric curves. The simulation experiments as well as real system experiments on a robot normally used in the robot soccer small league prove the applicability of the presented control approach.
ROV-based Underwater Vision System for Intelligent Fish Ethology Research
Authors: Nian Rui , He Bo , Yu Jia , Bao Zhenmin , Wang Yangfan
Published: September 2013

Fish ethology is a prospective discipline for ocean surveys. In this paper, one ROV-based system is established to perform underwater visual tasks with customized optical sensors installed. One image quality enhancement method is first presented in the context of creating underwater imaging models combined with homomorphic filtering and wavelet decomposition. The underwater vision system can further detect and track swimming fish from the resulting images with the strategies developed using curve evolution and particular filtering, in order to obtain a deeper understanding of fish behaviours. The simulation results have shown the excellent performance of the developed scheme, in regard to both robustness and effectiveness.
Evaluating Medication Use in Pregnancy and Lactation: What Every Pharmacist Should Know
Authors: Burkey Betsy Walters , Holmes Amy P.
Published: September 2013

As a pharmacist, being asked to give advice about medication use during pregnancy or lactation can be daunting. This article reviews the principles of drug transfer across the placenta, into breast milk, and reviews the rating scales and different resources available. The Food and Drug Administration classification scale is reviewed and the upcoming changes are explained, along with recent labeling changes for specific medications or drug classes when appropriate. This article provides the pharmacist with a practical set of tools to review the information available and assess the risks of treating or withholding a medication for mother and infant.
The Ghosts of Chroniclers Past: The Transmission and Legacy of the Chroniques of Jean Froissart in the Anchiennes Cronicques d’Engleterre compiled by Jean de Wavrin
Authors: Prud’Homme Caroline
Published: September 2013

Compared to Georges Chastellain or Jean Molinet, Jean de Wavrin is not a very well known figure of burgundian historiography; he is nonetheless the author of the Anchiennes cronicques d’Engleterre, an extensive historical compilation in six volumes that has not yet been edited in full. About 40% of the text is derived from the Chroniques of Jean Froissart.

This article investigates the transmission and the transformation of Froissart’s Chroniques into the Wavrin compilation through a close reading of an episode (the Flemish wars of 1379-85, Froissart, Book II; Wavrin, volume III) in manuscript context. It evaluates the extent to which Wavrin is faithful to Froissart, and explores complex issues of manuscript transmission. This article also examines Wavrin’s compiling method and his interventions on his source text taking into account the impact of these interventions on the reader, and the relationship between the materiality of the manuscript and its content.