Software Risk Management: a Process Model and a Tool

Abstract. This paper is concerned with the risks associated with the software development process. A model (GRisk-Model) is proposed for the management of such risks and a software tool (GRisk-Tool), developed to support the model, is described. Both the method and the tool were created with the participation of senior managers and software engineers of software factories. The model and the tool serve as effective instruments for achieving the continuous improvement of software processes and products

Vantagens educacionais no uso de jogos em Realidade Aumentada

O crescimento constante da indústria do entretenimento eletrônico é reflexo da grande aceitação dos jogadores, nas suas mais diversas faixas etárias e classes sociais. A integração da Realidade Aumentada neste setor está ganhando notoriedade devido a seu diferencial de interação e as novas formas de representação dos elementos virtuais. Este documento procura explorar as vantagens educacionais que podem ser transmitidas por estes jogos. Para melhor compreensão do assunto, um protótipo foi criado, com o uso da Realidade Aumentada, e sua análise está contida neste artigo

Radiocarbon dating organic residues at the microgram level

Relation between submilligram sample size and {sup 14}C activity for sample blanks (wood from Pliocene sediments) and a contemporary standard (oxalic acid) for catalytically reduced graphitic carbon was examined down to 20 micrograms. Mean age of the 1 mg wood sample blanks is now about 51.3 ka (0.168 pMC) while the mean for 20 microgram sample blanks is about 42.9 ka. So far, the lowest value for a 1-mg wood sample blank is about 60.5 ka (0.056 pMC). We have determined a mean {sup 14}C age of about 9.4 ka from a suite of 7 organic extracts from hair, bone, and matting from a mummified human skeleton from Spirit Cave, Nevada. These data indicate that the Spirit Cave human is the third, oldest directly-dated, human skeleton currently known from North America

Nanocrystalline silicon oxide interlayer in monolithic perovskite silicon heterojunction tandem solar cells with total current density gt;39 mA cm2

Silicon heterojunction solar cells are implemented as bottom cells in monolithic perovskite silicon tandem solar cells. Commonly they are processed with a smooth front side to facilitate wet processing of the lead halide perovskite cell on top. The inherent drawback of this design, namely, enhanced reflection of the cell, can be significantly reduced by replacing the amorphous or nanocrystalline silicon front side n layer of the silicon cell by a nanocrystalline silicon oxide n layer. It is deposited with the same commonly used plasma enhanced chemical vapor deposition and can be tuned to feature opto electrical properties for enhanced light coupling into the Si bottom cell, namely, low parasitic absorption and an intermediate refractive index of 2.6. We demonstrate that a 80 100 nm thick layer results in 0.9 mA cm 2 current gain in the bottom cell yielding tandem cells with a top cell bottom cell total current above 39 mA cm 2 . These first nc SiO x H coupled tandem cells reach an efficiency gt;23.

Inter-model comparison of global hydroxyl radical (OH) distributions and their impact on atmospheric methane over the 2000–2016 period

The modeling study presented here aims to estimate how uncertainties in global hydroxyl radical (OH) distributions, variability, and trends may contribute to resolving discrepancies between simulated and observed methane (CH4) changes since 2000. A multi-model ensemble of 14 OH fields was analyzed and aggregated into 64 scenarios to force the offline atmospheric chemistry transport model LMDz (Laboratoire de Meteorologie Dynamique) with a standard CH4 emission scenario over the period 2000–2016. The multi-model simulated global volume-weighted tropospheric mean OH concentration ([OH]) averaged over 2000–2010 ranges between 8:7*10^5 and 12:8*10^5 molec cm-3. The inter-model differences in tropospheric OH burden and vertical distributions are mainly determined by the differences in the nitrogen oxide (NO) distributions, while the spatial discrepancies between OH fields are mostly due to differences in natural emissions and volatile organic compound (VOC) chemistry. From 2000 to 2010, most simulated OH fields show an increase of 0.1–0:3*10^5 molec cm-3 in the tropospheric mean [OH], with year-to-year variations much smaller than during the historical period 1960–2000. Once ingested into the LMDz model, these OH changes translated into a 5 to 15 ppbv reduction in the CH4 mixing ratio in 2010, which represents 7%–20% of the model-simulated CH4 increase due to surface emissions. Between 2010 and 2016, the ensemble of simulations showed that OH changes could lead to a CH4 mixing ratio uncertainty of > 30 ppbv. Over the full 2000–2016 time period, using a common stateof- the-art but nonoptimized emission scenario, the impact of [OH] changes tested here can explain up to 54% of the gap between model simulations and observations. This result emphasizes the importance of better representing OH abundance and variations in CH4 forward simulations and emission optimizations performed by atmospheric inversions

Changes in work habits of lifeguards in relation to Florida red tide

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Harmful Algae 9 (2010): 419-425, doi:10.1016/j.hal.2010.02.005.The marine dinoflagellate, Karenia brevis, is responsible for Florida red tides. Brevetoxins, the neurotoxins produced by K. brevis blooms, can cause fish kills, contaminate shellfish, and lead to respiratory illness in humans. Although several studies have assessed different economic impacts from Florida red tide blooms, no studies to date have considered the impact on beach lifeguard work performance. Sarasota County experiences frequent Florida red tides and staffs lifeguards at its beaches 365 days a year. This study examined lifeguard attendance records during the time periods of March 1 to September 30 in 2004 (no bloom) and March 1 to September 30 in 2005 (bloom). The lifeguard attendance data demonstrated statistically significant absenteeism during a Florida red tide bloom. The potential economic costs resulting from red tide blooms were comprised of both lifeguard absenteeism and presenteeism. Our estimate of the costs of absenteeism due to the 2005 red tide in Sarasota County is about $3,000. On average, the capitalized costs of lifeguard absenteeism in Sarasota County may be on the order of$100,000 at Sarasota County beaches alone. When surveyed, lifeguards reported not only that they experienced adverse health effects of exposure to Florida red tide but also that their attentiveness and abilities to take preventative actions decrease when they worked during a bloom, implying presenteeism effects. The costs of presenteeism, which imply increased risks to beachgoers, arguably could exceed those of absenteeism by an order of magnitude. Due to the lack of data, however, we are unable to provide credible estimates of the costs of presenteeism or the potential increased risks to bathers.This research was supported by the National Science Foundation under The Research Experience for Undergraduate Program, grant number 0453955; the P01 ES 10594, DHHS NIH of the National Institute of Environmental Health Sciences; the Center for Oceans and Human Health at the Woods Hole Oceanographic Institution [National Science Foundation (NSF) OCE-0430724; National Institute of Environmental Health Sciences (NIEHS) P50 ES012742]; and the Ocean and Human Health Center at the University of Miami Rosenstiel School (NSF 0CE0432368; NIEHS 1 P50 ES12736)

Errors induced by different approximations in handling horizontal atmospheric inhomogeneities in MIPAS/ENVISAT retrievals

MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) is a mid-infrared limb emission sounder that operated on board the polar satellite ENVISAT from 2002 to 2012. The retrieval algorithm used by the European Space Agency to process MIPAS measurements exploits the assumption that the atmosphere is horizontally homogeneous. However, previous studies highlighted how this assumption causes significant errors on the retrieved profiles of some MIPAS target species. In this paper we quantify the errors induced by this assumption and evaluate the performances of three different algorithms that can be used to mitigate the problem. We generate synthetic observations with a high spatial resolution atmospheric model and carry out the retrievals with four alternative methods. The first assumes horizontal homogeneity (1-D retrieval), the second includes a model of the horizontal gradient of atmospheric temperature (1-D plus temperature gradient retrieval), the third accounts for an horizontal gradient of temperature and composition (1-D plus temperature and composition gradient retrieval), while the fourth is the full two-dimensional (2-D) inversion approach. Our results highlight that the 1-D retrieval implies errors that are significant for averages of profiles. Furthermore, for some targets (e.g. Τ , CH$_{4}$ and N$_{2}$O below 10 hPa) the error induced by the 1-D approximation also becomes visible in the individual retrieved profiles. The inclusion of any kind of horizontal variability model improves all the targets with respect to the horizontal homogeneity assumption. For temperature, HNO$_{3}$ and CFC-11, the inclusion of an horizontal temperature gradient leads to a significant reduction of the error. For other targets, such as H$_{2}$O, O$_{3}$, N$_{2}$O, CH$_{4}$, the improvements due to the inclusion of an horizontal temperature gradient are minor. In these cases, the inclusion of a gradient in the target volume mixing ratio leads to significant improvements. Among all the methods tested in this work, the 2-D approach, as expected, implies the smallest errors for almost all the target parameters. This residual error of the 2-D approach is the smoothing caused by the retrieval grid, which is coarser than that of the atmospheric model

The effect of atmospheric nudging on the stratospheric residual circulation in chemistry–climate models

We perform the first multi-model intercomparison of the impact of nudged meteorology on the stratospheric residual circulation using hindcast simulations from the Chemistry–Climate Model Initiative (CCMI). We examine simulations over the period 1980–2009 from seven models in which the meteorological fields are nudged towards a reanalysis dataset and compare these with their equivalent free-running simulations and the reanalyses themselves. We show that for the current implementations, nudging meteorology does not constrain the mean strength of the stratospheric residual circulation and that the inter-model spread is similar, or even larger, than in the free-running simulations. The nudged models generally show slightly stronger upwelling in the tropical lower stratosphere compared to the free-running versions and exhibit marked differences compared to the directly estimated residual circulation from the reanalysis dataset they are nudged towards. Downward control calculations applied to the nudged simulations reveal substantial differences between the climatological lower-stratospheric tropical upward mass flux (TUMF) computed from the modelled wave forcing and that calculated directly from the residual circulation. This explicitly shows that nudging decouples the wave forcing and the residual circulation so that the divergence of the angular momentum flux due to the mean motion is not balanced by eddy motions, as would typically be expected in the time mean. Overall, nudging meteorological fields leads to increased inter-model spread for most of the measures of the mean climatological stratospheric residual circulation assessed in this study. In contrast, the nudged simulations show a high degree of consistency in the inter-annual variability in the TUMF in the lower stratosphere, which is primarily related to the contribution to variability from the resolved wave forcing. The more consistent inter-annual variability in TUMF in the nudged models also compares more closely with the variability found in the reanalyses, particularly in boreal winter. We apply a multiple linear regression (MLR) model to separate the drivers of inter-annual and long-term variations in the simulated TUMF; this explains up to ∼75 % of the variance in TUMF in the nudged simulations. The MLR model reveals a statistically significant positive trend in TUMF for most models over the period 1980–2009. The TUMF trend magnitude is generally larger in the nudged models compared to their free-running counterparts, but the intermodel range of trends doubles from around a factor of 2 to a factor of 4 due to nudging. Furthermore, the nudged models generally do not match the TUMF trends in the reanalysis they are nudged towards for trends over different periods in the interval 1980–2009. Hence, we conclude that nudging does not strongly constrain long-term trends simulated by the chemistry–climate model (CCM) in the residual circulation. Our findings show that while nudged simulations may, by construction, produce accurate temperatures and realistic representations of fast horizontal transport, this is not typically the case for the slower zonal mean vertical transport in the stratosphere. Consequently, caution is required when using nudged simulations to interpret the behaviour of stratospheric tracers that are affected by the residual circulation

Trunk anatomical features and essential oils composition of woody-shrub species of the ecotone and steppe from the Northwestern region of Chubut Province

La Provincia del Chubut tiene una superficie aproximada de 224.686 km2, donde los bosques subantárticos se extienden hacia el oeste y el noroeste. Están compuestos por árboles nativos como la lenga, el coihue, el alerce o lahuán, el ciprés, el maitén, el ñire y el radal, entre otros. En el ecotono bosque-estepa incursionan algunas de estas especies arbóreas, pero existe mayor predominancia de arbustos de muy bajo porte. El objetivo de este trabajo fue analizar, sobre la base de los caracteres anatómicos del leño secundario, aspectos xeromórficos de arbustos patagónicos y determinar la presencia y la composición de los aceites esenciales en sus follajes. Se realizó el estudio anatómico de algunas especies arbustivas, comprendidas en las siguientes familias botánicas: Apiaceae, Asteraceae, Fabaceae, Lamiaceae, Malvaceae, Rhamnaceae, Solanaceae y Verbenaceae. Se realizó el estudio anatómico de: Adesmia boronioides (Fabaceae), Ameghinoa patagonica (Asteraceae), B. obovata, B. salicifolia, (Asteraceae), Clinopodium darwinii (Lamiaceae), Corynabutilon bicolor (Malvaceae), Diostea juncea (Verbenaceae), Discaria chacaye (Rhamnaceae), Fabiana imbricata (Solanaceae), Mulinum spinosum (Apiaceae), Ochetophila trinervis (Rhamnaceae), Schinus johnstonii y S. patagonicus (Anacardiaceae). Los elementos observados, analizados y medidos permitieron obtener resultados y establecer analogías y diferencias entre las especies. La mayoría de los arbustos presenta: porosidad de circular a semicircular en xilema temprano, y porosidad difusa, disposición dendrítica, ulmoide, en racimos, y oblicua en zigzag, en xilema tardío. En sección transversal, los poros se distribuyen solitarios, múltiples radiales cortos, largos y en cadena; en sección tangencial se observaron radios uni a multiseriados, homocelulares y heterocelulares. El sistema de radios es heterogéneo. Los espesamientos helicoidales están presentes en las paredes de los vasos y las traqueidas vasculares de varias especies. En el leño de otras, se hallaron traqueidas vasicéntricas y fibrotraqueidas. Las perforaciones reticuladas solo fueron halladas en algunos vasos de Ochetophila trinervis; y perforaciones radiovasculares, en D. chacaye. Las demás especies tienen vasos con perforaciones simples. Los valores de índice de vulnerabilidad, mesomorfismo, índice de fibras/vasos y frecuencia promedio de poros/mm2 obtenidos, demuestran que los arbustos estudiados habitan en sitios de xerófitos a extremadamente xéricos del ecotono-estepa del Chubut. El 64% de las especies mostró contenidos importantes de aceites esenciales. Este resultado estaría en concordancia con algunas hipótesis que plantean la presencia de estos metabolitos secundarios como adaptación a las condiciones xerófitas.Chubut Province has an area of about 224.686 km², and therein the sub Antarctic forest extends to the West and Northwest. Native trees such as lenga, coihue, alerce or lahuán, cypress, maitén, ñire and radal, among others, are the most frequent species present. Meanwhile in the forest-steppe of the ecotone some of these tree species are also present but with a greater predominance of very low bearing shrubs. The objective of this study was to analyze the xeromorphic aspects of patagonian shrubs based on the anatomical characters of the secondary wood and on the presence and composition of essential oils in their foliage. The anatomical study was conducted on: Adesmia boronioides (Fabaceae), Ameghinoa patagonica (Asteraceae), Baccharis linearis, B. obovata, B. salicifolia, (Asteraceae), Clinopodium darwinii (Lamiaceae), Corynabutilon bicolor (Malvaceae), Diostea juncea (Verbenaceae), Discaria chacaye (Rhamnaceae), Fabiana imbricata (Solanaceae), Mulinum spinosum (Apiaceae), Ochetophila trinervis (Rhamnaceae), Schinus johnstonii y S. patagonicus (Anacardiaceae). The anatomical elements observed, analyzed and measured, allowed establishing analogies and differences between the species. Most of the bushes presented: circular to semicircular porosity in spring wood, and diffuse-porous, dendritic provision, ulmoid, in clusters, and oblique zigzag in autumn-winter wood. In cross section, the pores were solitare, multiple radial short, long and chain; uni multiseriate, homocellular and heterocellular rays were observed in the tangential section. The radio system was heterogeneous. The helical thickening was present in the vessel walls and vascular tracheids, of several species. Fibrotracheids and vasicentric tracheids were found in the others woods. The reticulate perforations were only found in some vessels of Ochetophila trinervis; and radiovasculars drillings in D. chacaye. Other species had vessels with simple perforations. Index values of vulnerability, mesomorphism, index of fibers/vessels and frequency average pores/mm² obtained, demonstrated that the shrubs under study live in xerophytic to extremely xeric conditions in the ecotone-steppe in Chubut. About 64% of the species showed essential oils content. These results would be consistent with some hypotheses posed that the presence of these secondary metabolites constitutes a possible adaptation to xerophytic conditions.Fil: Guerra, Pedro E.. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ingeniería - Sede Esquel; ArgentinaFil: González, Silvia Beatriz. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel; ArgentinaFil: Kirner, Helga J.. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ingeniería - Sede Esquel; ArgentinaFil: Retta, Daiana Sabrina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Di Leo Lira, Paola Maria del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Gómez, Mariano F.. Centro de Investigación y Extensión Forestal Andino Patagónico; Argentin