Permafrost degradation on a warmer Earth: Challenges and perspectives

Permafrost, the permanently frozen ground, is warming due to global temperature rise. Permafrost research has progressed rapidly in the last decade, as large areas in the Polar Regions, in mountain environments and on high-altitude plateaus are experiencing accelerated environmental changes in response to thaw and permafrost degradation. Climate scenarios for the next decades project a reduced the extent of permafrost coverage and increasing ground temperatures, promoting changes in terrestrial and nearshore ecosystem dynamics. Future research in permafrost regions should focus on a better understanding of the biogeochemical cycles associated with abrupt and long-term permafrost degradation. Risk assessment of natural hazards and geoenvironmental engineering solutions are needed to reduce the potential dramatic socio-economic implications that permafrost degradation may entail in these regions

Geomorphological processes and frozen ground conditions in Elephant Point (Livingston Island, South Shetland Islands, Antarctica)

Elephant Point is an ice-free area in the SW corner of Livingston Island (Maritime Antarctica). The retreat of Rotch Dome glacier during the Holocene has exposed a land area of 1.16 km2 . Up to 17.3% of this surface has become ice-free between 1956 and 2010. A detailed geomorphological mapping of this ice-free environment was conducted in late January 2014. A wide range of active periglacial landforms show that periglacial processes are widespread. From the glacier to the coast four different geomorphological areas are identified: proglacial environment, moraine complex, bedrock plateaus and marine terraces. In situ measurements of the thawed soil depth show evidence of the widespread frozen ground conditions in the area. Field observations of permafrost exposures suggest that these frost conditions may be related to a soil permafrost regime, almost down to sea level. The activity of penguin colonies and elephant seals has created minor geomorphological features in the raised marine terraces. Here, several archaeological sites related to early human colonization of Antarctica were also found in natural shelters.info:eu-repo/semantics/publishedVersio

Factores que condicionan los procesos periglaciares de vertiente actuales en Sierra Nevada. El caso de la solifluxión.

Los procesos periglaciares de vertiente presentan una actividad moderada en las más altas cumbres de la Península Ibérica. Centrados en los tramos más elevados de Sierra Nevada se ha analizado la eficacia de los procesos solifluidales actuales. Para ello se discuten los factores que condicionan la solifluxión, en particular el régimen térmico y el cometido de la disponibilidad hídrica en el suelo. La monitorización dinámica llevada a término en sectores instalados en torno a los 3.000 m, en condiciones climáticas de suelo helado estacional, sin permafrost, evidencia una actividad muy limitada. Factors controlling present-day periglacial slope processes in Sierra Nevada (South Spain). The case of solifluction Periglacial slope processes have a moderate activity in the highest mountains of the Iberian Peninsula. Focusing on the summits of Sierra Nevada, the contemporary dynamics of solifluction processes has been studied. With this purpose, we discuss the factors conditioning solifluction processes, with an especial focus on the role played by the ground thermal regime and water availability. Dynamic monitoring of solifluction landforms located at environments of about 3000 m, where seasonal frost exists, without permafrost, shows evidence of a very limited activity

Modelling extreme precipitation in hazardous mountainous areas. Contribution to landscape planning and environmental management

Extreme precipitation episodes are very common in Mediterranean area and can lead to serious and catastrophic environmental hazards. They have special incidence during autumn months, September, October and November (SON) with important impacts on society, leading frequently to significant economic losses and mortality. These events have special impact in mountainous areas where steep slopes enhance the effects of extreme precipitation. In mountainous areas rain gauge stations are sparse and normally in lower amount. Due to these reasons it is very important to map with higher accuracy the distribution of extreme precipitation. Also, in mountainous environments precipitation patterns can change in small distances that make the prediction more difficult, but also more important. A better prediction of areas with higher values of extreme precipitation will contribute to a better land use planning and avoid the effects of flash floods, land‐slides and soil erosion recognized as environmental problems. The aim of this paper is testing several well‐known interpolation methods, Inverse Distance Weight (IDW) with weighs of 1, 2, 3, 4 and 5, Local Polynomial (LP) with order 1 and 2, Radial Basis Methods (RBS), particularly Spline With Tension (SPT) and Thin Plate Spline (TPS), and Kriging techniques, Ordinary Kriging (OK) and Ordinary CoKriging (COK) in order to identify the less‐biased method to interpolate extreme precipitation calculated from the 95th percentile (P95) of SON precipitation in a mountainous area located in Portugal. The results show that extreme precipitation increases with the altitude and there are important differences between stations located at higher and lower altitudes. This relation is observed in the omni‐directional semi‐variograms calculated where we identified two major P95 areas coincident with higher elevations. The first one occurred at 12.19 km and the second at 23.57 km. The higher values of P95 are identified at Southeast and Northeast. In contrast, the lower P95 values are identified at Northwest due to lower altitudes and in the Northeast corner as a consequence of rain shadow effect. Prediction with precision of precipitation patterns in mountainous areas is difficult due to lack of data and the complex effect of topography in rainfall, however, it is of major importance in order to identify vulnerable areas. The findings observed in this study are a fundamental contribution to landscape planning and environmental management in areas with higher occurrence and vulnerability to extreme precipitation. Article in English. Gausių kritulių pasiskirstymo poveikio pavojingose kalnų vietovėse modeliavimas. Pagalba planuojant kraštovaizdį, aplinkos valdymą Santrauka. Gausūs krituliai, ypač būdingi Viduržemio jūros regionui, gali kelti rimtų pavojų aplinkai, lemti katastrofas. Kritulių poveikio zona ypač išsiplečia rudens laikotarpiu, t. y. rugsėjo, spalio ir lapkričio (RSL) mėnesiais, neretai patiriama didelių ekonominių nuostolių, žūsta ar kitaip nukenčia žmonės. Statūs kalnų šlaitai sustiprina gausių kritulių poveikį. Kalnuotose vietovėse kritulių kiekio stebėjimo stočių nedaug, jos toli viena nuo kitos, todėl labai aktualu turėti žemėlapius, tiksliai nusakančius gausių kritulių pasiskirstymą. Kalnuotose vietovėse krituliu pobūdis skirtingų atstumu gali būti skirtingas, kritulių kieki numatyti sunkiau, tačiau tai itin svarbu. Tiksliau numatant vietoves, kur iškrenta daugiau kritulių, galima tikslingiau planuoti žemėtvarką, išvengti staigiu potvynių, nuošliaužų ir dirvožemio erozijos. Tyrimo tikslas buvo patikrinti kelis gerai žinomus interpoliacijos metodus – Inverse Distance Weight (IDW) su 1–5 svertinemis vertėmis, Local Polynomial (LP), Radial Basis (RBS), ypač Spline With Tension (SPT), Thin Plate Spline (TPS), – bei Kriging technikas ir Ordinary Kriging (OK) bei Ordinary CoKriging (COK) metodus, siekiant parinkti tiksliausią, kuris leistų interpoliuoti gausius (95 %) kritulius RSL mėnesiais kalnuotoje Portugalijos teritorijoje. Nustatyta, kad kritulių kiekis didėja didėjant altitudei. Reikšmingi kritulių skirtumai nustatyti stotyse, esančiose skirtinguose aukščiuose virš jūros lygio. Šis santykis pastebėtas visomis kryptimis apskaičiuotose pusinėse variogramose. Jose išsiskiria dvi teritorijos, kurių P95 vertes didžiausios, ir akivaizdi sąsaja su dildelėmis altitudemis. Pirmoji teritorija 12,19 km, o antroji 23,57 km aukštyje. Didžiausios P95 vertes pietryčių ir šiaurės rytų kryptimis, mažiausios – šiaurės vakarų kryptimi, kur altitudės mažos, ir šiaurės rytų teritorijos kampe dėl lietaus “šešėlio” efekto. Tiksliai numatyti kritulių pobūdį kalnuotose teritorijose apsunkina duomenų trūkumas ir sudėtinga topografijos įtaka krituliams. Rezultatai ypač parankūs planuojant ir valdant dažniems ir gausiems krituliams jautrias teritorijas. Reikšminiai žodžiai: gausūs krituliai, pavojus aplinkai, Viduržemio regionas, rugsėjis, spalis, lapkritis (RSL), kalnuotos vietovės, interpoliacijos metodai, kraštovaizdžio planavimas ir aplinkos valdymas. Моделирование влияния распределения обильных осадков в опасных горных местностях. Помощь в планировании ландшафта и управлении окружающей средой Резюме. Обильные осадки, особенно характерные для Средиземноморского региона, могут быть опасными для окружающей среды. Зона влияния осадков особенно увеличивается в осенний период – сентябре, октябре и ноябре. Осадки зачастую вызывают большие экономические убытки, гибнут или страдают люди. Влияние обильных осадков усиливают крутые горные склоны. В горных местностях станций наблюдения за количеством осадков немного и расположены они далеко друг от друга, поэтому необходимы карты, на которых было бы точно указано распределение обильных осадков. Характер осадков в горных местностях в зависимости от удаленности может значительно различаться, предвидеть количество осадков чрезвычайно сложно, однако это жизненно необходимо. Зная местности, на которых ожидается большее количество осадков, можно точнее планировать землеустройство, избежать внезапных наводнений, оползней и эрозии почв. Целью исследования было проверить несколько хорошо известных методов интерполяции – Inverse Distance Weight (IDW) с 1–5 значениями весомостей, Local Polynomial (LP), Radial Basis (RBS), особенно Spline With Tension (SPT), Thin Plate Spline (TPS), а также технику Kriging, методы Ordinary Kriging (OK) и Ordinary CoKriging (COK) с целью выявить наиболее точный, с помощью которого можно было бы интерполировать обильные (95%) осенние осадки в горных местностях Португалии. Установлено, что количество осадков увеличивается с увеличением амплитуды. Значительная разница в количестве осадков выявлена на станциях, находящихся на разной высоте от уровня моря. Это соотношение замечено на всех направлениях рассчитанных полувариограмм. На них выделяются две территории, на которых значения P95 наиболее велики и очевидна связь с большими амплитудами. Первая территория находится на высоте 12,19 км, вторая – 23,57 км. Наибольшие значения P95 отмечены в юго-восточном и северо-восточном, наименьшие – северо-западном направлениях, где амплитуды малы, и в углу северо-восточной территории из-за эффекта «тени» дождя. Точнее предвидеть характер осадков в горных местностях представляется затруднительным из-за недостатка данных и сложного влияния на осадки топографии. Результаты исследования окажутся особенно полезными при планировании и управлении территориями, подвергаемыми частым и обильным осадкам. Ключевые слова: обильные осадки, опасность для окружающей среды, Средиземноморский регион, осенний период, горная местность, методы интерполяции, планирование ландшафта и управление окружающей средой. First Publish Online: 10 Feb 201

Deep Message Passing on Sets

Modern methods for learning over graph input data have shown the fruitfulness of accounting for relationships among elements in a collection. However, most methods that learn over set input data use only rudimentary approaches to exploit intra-collection relationships. In this work we introduce Deep Message Passing on Sets (DMPS), a novel method that incorporates relational learning for sets. DMPS not only connects learning on graphs with learning on sets via deep kernel learning, but it also bridges message passing on sets and traditional diffusion dynamics commonly used in denoising models. Based on these connections, we develop two new blocks for relational learning on sets: the set-denoising block and the set-residual block. The former is motivated by the connection between message passing on general graphs and diffusion-based denoising models, whereas the latter is inspired by the well-known residual network. In addition to demonstrating the interpretability of our model by learning the true underlying relational structure experimentally, we also show the effectiveness of our approach on both synthetic and real-world datasets by achieving results that are competitive with or outperform the state-of-the-art.Comment: 11 pages, 8 figure

Evaluation of frozen ground conditions along a coastal topographic gradient at Byers Peninsula (Livingston Island, Antarctica) by geophysical and geoecological methods

Geophysical surveying and geoelectricalmethods are effective to study permafrost distribution and conditions in polar environments. Geoelectrical methods are particularly suited to study the spatial distribution of permafrost because of its high electrical resistivity in comparison with that of soil or rock above 0 °C. In the South Shetland Islands permafrost is considered to be discontinuous up to elevations of 20–40ma.s.l., changing to continuous at higher altitudes. There are no specific data about the distribution of permafrost in Byers Peninsula, in Livingston Island, which is the largest ice-free area in the South Shetland Islands. With the purpose of better understanding the occurrence of permanent frozen conditions in this area, a geophysical survey using an electrical resistivity tomography (ERT)methodologywas conducted during the January 2015 field season, combined with geomorphological and ecological studies. Three overlapping electrical resistivity tomographies of 78meach were done along the same profile which ran from the coast to the highest raised beaches. The three electrical resistivity tomographies are combined in an electrical resistivitymodel which represents the distribution of the electrical resistivity of the ground to depths of about 13malong 158m. Several patches of high electrical resistivity were found, and interpreted as patches of sporadic permafrost. The lower limits of sporadic to discontinuous permafrost in the area are confirmed by the presence of permafrost-related landforms nearby. There is a close correspondence between moss patches and permafrost patches along the geoelectrical transect

Safety culture maturity in several latin America mining activities

Health and safety is a crucial issue in the mining industry because of the implication of fatalities in this sector. A study of safety culture maturity in several Latin America countries has been done based on the model from Filho et al. [1]. The questionnaire includes 28 items regarding the type of activity, number of employees and safety culture characteristics of the activity: Information of accidents and misses, organizational structure to deal with the information, involvement of the company in health and safety issues, the way it communicates accidents and misses and commitment of the company towards health and safety. The questionnaire was completed by 58 mining company managers from Bolivia, Peru, Colombia and Mexico. Results show different behaviours depending on the type of company, cooperative or private company. When private companies are analysed, it is seen a level of maturity according to the size of the company, whereas cooperatives does not have a clear trend in terms of size apart from very small cooperatives, less than 10 employees. However, there is a remarkable difference between cooperatives that have implemented continuous improvement systems and the others. In particular, cooperatives with a continuous improvement system have been analysed, displaying much higher safety culture levels. Therefore, it can be concluded that private companies improve their level of safety culture as the size of the company increase, because procedures and control systems are implemented. When cooperative or small companies introduce similar systems they also achieve substantial gains, but their approach is different. Managers from cooperatives have to see economic reasons to implement it, such as the Fairmined certificate.Peer ReviewedPostprint (published version

Cetuximab-Containing Combinations in Locally Advanced and Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma

Cetuximab remains to date the only targeted therapy approved for the treatment of head and neck squamous cell carcinoma (HNSCC). The EGFR pathway plays a key role in the tumorigenesis and progression of this disease as well as in the resistance to radiotherapy (RT). While several anti-EGFR agents have been tested in HNSCC, cetuximab, an IgG1 subclass monoclonal antibody against EGFR, is the only drug with proven efficacy for the treatment of both locoregionally-advanced (LA) and recurrent/metastatic (R/M) disease. The addition of cetuximab to radiotherapy is a validated treatment option in LA-HNSCC. However, its use has been limited to patients who are considered unfit for standard of care chemoradiotherapy (CRT) with single agent cisplatin given the lack of direct comparison of these two regimens in randomized phase III trials and the inferiority suggested by metanalysis and phase II studies. The current use of cetuximab in HNSCC is about to change given the recent results from randomized prospective clinical trials in both the LA and R/M setting. Two phase III studies evaluating RT-cetuximab vs. CRT in Human Papillomavirus (HPV)-positive LA oropharyngeal squamous cell carcinoma (De-ESCALaTE and RTOG 1016) showed inferior overall survival and progression-free survival for RT-cetuximab combination, and therefore CRT with cisplatin remains the standard of care in this disease. In the R/M HNSCC, the EXTREME regimen has been the standard of care as first-line treatment for the past 10 years. However, the results from the KEYNOTE-048 study will likely position the anti-PD-1 agent pembrolizumab as the new first line treatment either alone or in combination with chemotherapy in this setting based on PD-L1 status. Interestingly, cetuximab-mediated immunogenicity through antibody dependent cell cytotoxicity (ADCC) has encouraged the evaluation of combined approaches with immune-checkpoint inhibitors in both LA and R/M-HNSCC settings. This article reviews the accumulated evidence on the role of cetuximab in HNSCC in the past decade, offering an overview of its current impact in the treatment of LA and R/M-HNSCC disease and its potential use in the era of immunotherapy

Lóbulos de solifluxión y fluctuaciones paleoclimáticas durante el holoceno en Sierra Nevada

Ponencia presentada en: VI Congreso Internacional de la Asociación Española de Climatología celebrado en Tarragona del 8 al 11 de octubre de 2008.[ES]Sierra Nevada concentra las cumbres más altas de la Península Ibérica (Mulhacén 3.478 m., Veleta 3.398 m.). Las cabeceras de los valles de San Juan y Río Seco presentan numerosos lóbulos de solifluxión, cuyo control dinámico demuestra una actividad muy leve de los procesos solifluidales bajo las actuales condiciones climáticas. La génesis y desarrollo de los lóbulos se concibe durante unas condiciones más propicias, ligadas a temperaturas más bajas y/o mayores índices de humedad. El análisis sedimentológico de los lóbulos de solifluxión permite deducir fases de actividad solifluidal (e.g. Pequeña Edad de Hielo) alternándose con periodos de desarrollo edáfico (e.g. Óptimo Climático Medieval) durante el Holoceno tardío.[EN]Sierra Nevada concentrates the highest peaks in the Iberian Peninsula (Mulhacén, 3.478 m., Veleta 3.398 m.). Headwaters of San Juan and Río Seco valleys have an important number of solifuction lobes, but dynamic control reports a very weak solifluction activity in the massif. These lobes must have formed and developed under different climate conditions, possibly related to lower temperatures and/or higher moisture conditions. Sedimentological studies of different solifluction lobes show phases of enhanced solifluction activity during the Late Holocene (e.g. Little Ice Age) alternated with periods of edaphic development (e.g. Medieval Warm Period).Se agradece el apoyo del Grup de Recerca Consolidat Paisatge i paleoambients a la muntanya mediterrània y de los proyectos 017/2007 de Parques Nacionales (MMA) y Fluvalps-3000 (CGL2006-01111)

La geomorfologia a Catalunya: situació actual i perspectives de futur

S'analitza l'evolució de la geomorfologia a Catalunya durant els darrers anys, fent una diagnosi crítica de la seva situació actual. Es discriminen els principals àmbits temàtics en els quals se centren els especialistes de la disciplina, així com les noves oportunitats que brinden les noves tècniques i metodologies. Finalment, en base a aquestes consideracions, l'article reflexiona sobre les debilitats i fortaleses que presenta la geomorfologia de cara als propers anys.We analyze the evolution of geomorphology in Catalonia during the last years, making a critical assessment of its current state. We examine the main topics studied by researchers, as well as the new opportunities opened by new techniques and methodologies. Finally, based on these considerations, we discuss about the weaknesses and strengths that geomorphology will have to face over the forthcoming years.Se analiza la evolución de la geomorfología en Cataluña durante los últimos años, haciendo una diagnosis crítica de su situación actual. Se discriminan los principales ámbitos temáticos en los que se centran los especialistas de la disciplina, así como las nuevas oportunidades que brindan las nuevas técnicas y metodologías. Finalmente, en base a estas consideraciones, el artículo reflexiona sobre las debilidades y fortalezas que presenta la geomorfología de cara a los próximos años