Recent and Future Warm Extreme Events and High-mountain Slope Stability

The number of large slope failures in some high-mountain regions such as the European Alps has increased during the past two to three decades. There is concern that recent climate change is driving this increase in slope failures, thus possibly further exacerbating the hazard in the future. Although the effects of a gradual temperature rise on glaciers and permafrost have been extensively studied, the impacts of short-term, unusually warm temperature increases on slope stability in high mountains remain largely unexplored. We describe several large slope failures in rock and ice in recent years in Alaska, New Zealand and the European Alps, and analyse weather patterns in the days and weeks before the failures. Although we did not find one general temperature pattern, all the failures were preceded by unusually warm periods; some happened immediately after temperatures suddenly dropped to freezing. We assessed the frequency of warm extremes in the future by analysing eight regional climate models from the recently completed European Union programme ENSEMBLES for the central Swiss Alps. The models show an increase in the higher frequency of high-temperature events for the period 2001–2050 compared with a 1951–2000 reference period. Warm events lasting 5, 10 and 30 days are projected to increase by about 1.5–4 times by 2050 and in some models by up to 10 times. Warm extremes can trigger large landslides in temperature-sensitive high mountains by enhancing the production of water by melt of snow and ice, and by rapid thaw. Although these processes reduce slope strength, they must be considered within the local geological, glaciological and topographic context of a slope

Amino acid transport in schistosomes: Characterization of the permeaseheavy chain SPRM1hc

Schistosomes are human parasitic flatworms that constitute an important public health problem globally. Adult parasites live in the bloodstream where they import nutrients such as amino acids across their body surface (the tegument). One amino acid transporter, Schistosome Permease 1 light chain, SPRM1lc, a member of the glycoprotein-associated family of transporters (gpaAT), has been characterized in schistosomes. Only a single member of the SLC3 family of glycoproteins that associate with gpaATs is found following extensive searching of the genomes of Schistosoma mansoni and S. japonicum. In this report, we characterize this schistosome permease heavy chain (SPRM1hc) gene and protein. The 72-kDa gene product is predicted to possess a single transmembrane domain, a (betaalpha)(8) (TIM barrel) conformation and a catalytic triad. Xenopus oocytes functionally expressing SPRM1hc with SPRM1lc import phenylalanine, arginine, lysine, alanine, glutamine, histidine, tryptophan, and leucine. Biochemical characterization demonstrates that in Xenopus extracts and in schistosome extracts SPRM1hc is associated into a high molecular weight complex with SPRM1lc that is disrupted by reducing agents. Quantitative real-time PCR and Western analysis demonstrate that SPRM1hc is expressed in each schistosome life stage examined (eggs, cercariae, schistosomula, adult males and females). SPRM1hc is widely distributed throughout adult male and female worms as determined by immunolocalization. Consistent with the hypothesis that SPRM1hc functions to facilitate nutrient uptake from host blood, immunogold electron microscopy confirms that the protein is distributed on the host-interactive tegumental membranes. We propose that surface-exposed, host-interactive, nutrient-transporting proteins like the SPRM1 heterodimer are promising vaccine candidates

Climate change-related risks and adaptation potential in Central and South America during the 21st century

Climate-related risks in Central and South America have received increased attention and concern in science and policy, but an up-to-date comprehensive review and synthesis of risks and adaptation potential is currently missing. For this paper we evaluated over 200 peer-reviewed articles and grey literature documents published since 2012. We found that climate change in Central and South America during the 21st century may increase the risk to severe levels for the following topical risk clusters: (a) Food insecurity; (b) Floods and landslides; (c) Water scarcity; (d) Epidemics of vector-borne diseases; (e) Amazon Forest biome shift; (f). Coral bleaching; (g) Coastal risks of sea level rise, storm surges and erosion; (h) Systemic failure due to cascading impacts of hazards and epidemics. Our synthesis also identified feasible adaptation measures for each risk. The impacts of the risks will be heterogeneous throughout the region, with rural communities, Indigenous peoples, Afro-Latin Americans, women, disabled people, and migrants identified as being the most severely affected. We refer to a number of adaptation options for each risk. However, unabated climate change together with low adaptive capacity will strictly limit adaptation options. Immediate strengthening of policies for building adaptive capacity and increase of research on the risk-adaptation nexus in Central and South America are paramount. Our findings might contribute to guide the adjustment and emphasis of adaptation policies and climate risk management strategies from local to national level

Estimating the volume of glaciers in the Himalayan–Karakoram region using different methods

Ice volume estimates are crucial for assessing water reserves stored in glaciers. Due to its large glacier coverage, such estimates are of particular interest for the Himalayan–Karakoram (HK) region. In this study, different existing methodologies are used to estimate the ice reserves: three area–volume relations, one slope-dependent volume estimation method, and two ice-thickness distribution models are applied to a recent, detailed, and complete glacier inventory of the HK region, spanning over the period 2000–2010 and revealing an ice coverage of 40 775 km2. An uncertainty and sensitivity assessment is performed to investigate the influence of the observed glacier area and important model parameters on the resulting total ice volume. Results of the two ice-thickness distribution models are validated with local ice-thickness measurements at six glaciers. The resulting ice volumes for the entire HK region range from 2955 to 4737 km3, depending on the approach. This range is lower than most previous estimates. Results from the ice thickness distribution models and the slope-dependent thickness estimations agree well with measured local ice thicknesses. However, total volume estimates from area-related relations are larger than those from other approaches. The study provides evidence on the significant effect of the selected method on results and underlines the importance of a careful and critical evaluation

The Tegument of the Human Parasitic Worm Schistosoma mansoni as an Excretory Organ: The Surface Aquaporin SmAQP Is a Lactate Transporter

Adult schistosomes are intravascular parasites that metabolize imported glucose largely via glycolysis. How the parasites get rid of the large amounts of lactic acid this generates is unknown at the molecular level. Here, we report that worms whose aquaporin gene (SmAQP) has been suppressed using RNAi fail to rapidly acidify their culture medium and excrete less lactate compared to controls. Functional expression of SmAQP in Xenopus oocytes demonstrates that this protein can transport lactate following Michaelis-Menten kinetics with low apparent affinity (Km = 41±5. 8 mM) and with a low energy of activation (Ea = 7.18±0.7 kcal/mol). Phloretin, a known inhibitor of lactate release from schistosomes, also inhibits lactate movement in SmAQP-expressing oocytes. In keeping with the substrate promiscuity of other aquaporins, SmAQP is shown here to be also capable of transporting water, mannitol, fructose and alanine but not glucose. Using immunofluorescent and immuno-EM, we confirm that SmAQP is localized in the tegument of adult worms. These findings extend the proposed functions of the schistosome tegument beyond its known capacity as an organ of nutrient uptake to include a role in metabolic waste excretion

ERUPTIVE ACTIVITY AND GLACIER CHANGES AT POPOCATEPETL VOLCANO, MEXICO

  The aim of the present work is the study of the eruptive activity-glacier interaction and, the effects on glacier evolution over 1994-2001. The glacial regime, morphological changes and infuence of the eruptive processes were determined in order to establish the eruptive activity-glacier interaction. Mass balances were carried out by means of photogrammetric techniques in order to determine the infuence of eruptive activity on the glacial regime. DEM comparisons allowed establishing spatial and temporal changes of area and volume of the glacier. Morphological changes were determined by photointerpretation, so the data obtained by this procedure and the data derived from DTM comparison were correlated to eruptive activity. The mass balance, and morphological changes at Popocatépetl volcano over 1994-2001 suggest that the eruptive activity accelerated the glacial retreat and cause its fragmentation.   Keywords: Popocatépetl Volcano, volcano-ice interactions, digital photogrammetry, glacial retreat.  El presente trabajo, se centra en el estudio del impacto de la actividad eruptiva del volcán Popocatépetl en el área glaciar durante el período 1994-2001. Para determinar el efecto de la actividad eruptiva en el régimen glaciar, se realizaron balances de masa empleando técnicas fotogramétricas, mediante la generación de modelos digitales de elevación (MDE). La compa­ración de MDEs permitió establecer los cambios glaciares en términos de área y volumen tanto temporales como espaciales. Así mismo, los cambios morfológicos del área glaciar fueron determinados con base en la fotointerpretación, de manera que los datos obtenidos por este procedimiento y los obtenidos mediante la comparación de los MDE se relacionaron con la actividad eruptiva a lo largo del periodo de estudio, estableciendo así la relación entre los fenómenos volcánicos y los cambios glaciares. Los resultados estimados del balance de masa del área glaciar y los cambios morfológicos observados a lo largo de 1994-2001 en el volcán Popocatépetl, permiten establecer que la actividad eruptiva aceleró el proceso de retroceso glaciar que tenía lugar desde principios del siglo XX y que culminó con la fragmentación del área glaciar.   Palabras clave: volcán Popocatépetl, interacción actividad eruptiva-glaciares, fotogrametría digital, retroceso glaciar.     &nbsp

ERUPTIVE ACTIVITY AND GLACIER CHANGES AT POPOCATEPETL VOLCANO, MEXICO

  The aim of the present work is the study of the eruptive activity-glacier interaction and, the effects on glacier evolution over 1994-2001. The glacial regime, morphological changes and infuence of the eruptive processes were determined in order to establish the eruptive activity-glacier interaction. Mass balances were carried out by means of photogrammetric techniques in order to determine the infuence of eruptive activity on the glacial regime. DEM comparisons allowed establishing spatial and temporal changes of area and volume of the glacier. Morphological changes were determined by photointerpretation, so the data obtained by this procedure and the data derived from DTM comparison were correlated to eruptive activity. The mass balance, and morphological changes at Popocatépetl volcano over 1994-2001 suggest that the eruptive activity accelerated the glacial retreat and cause its fragmentation.   Keywords: Popocatépetl Volcano, volcano-ice interactions, digital photogrammetry, glacial retreat.  El presente trabajo, se centra en el estudio del impacto de la actividad eruptiva del volcán Popocatépetl en el área glaciar durante el período 1994-2001. Para determinar el efecto de la actividad eruptiva en el régimen glaciar, se realizaron balances de masa empleando técnicas fotogramétricas, mediante la generación de modelos digitales de elevación (MDE). La compa­ración de MDEs permitió establecer los cambios glaciares en términos de área y volumen tanto temporales como espaciales. Así mismo, los cambios morfológicos del área glaciar fueron determinados con base en la fotointerpretación, de manera que los datos obtenidos por este procedimiento y los obtenidos mediante la comparación de los MDE se relacionaron con la actividad eruptiva a lo largo del periodo de estudio, estableciendo así la relación entre los fenómenos volcánicos y los cambios glaciares. Los resultados estimados del balance de masa del área glaciar y los cambios morfológicos observados a lo largo de 1994-2001 en el volcán Popocatépetl, permiten establecer que la actividad eruptiva aceleró el proceso de retroceso glaciar que tenía lugar desde principios del siglo XX y que culminó con la fragmentación del área glaciar.   Palabras clave: volcán Popocatépetl, interacción actividad eruptiva-glaciares, fotogrametría digital, retroceso glaciar.     &nbsp

Loss and Damage in the mountain cryosphere

The mountain cryosphere, which includes glaciers, permafrost, and snow, is one of the Earth’s systems most strongly affected by climate change. In recent decades, changes in the cryosphere have been well documented in many high-mountain regions. While there are some benefits from snow and ice loss, the negative impacts, including from glacier lake outburst floods and variations in glacier runoff, are generally considered to far outweigh the positive impacts, particularly if cultural impacts are considered. In international climate policy, there has been growing momentum to address the negative impacts of climate change, or ‘Loss and Damage’ (L&D) from climate change. It is not clear exactly what can and should be done to tackle L&D, but researchers and practitioners are beginning to engage with policy discussions and develop potential frameworks and supporting information. Despite the strong impact of climate change on the mountain cryosphere, there has been limited interaction between cryosphere researchers and L&D. Therefore, little work has been done to consider how L&D in the mountain cryosphere might be conceptualized, categorized, and assessed. Here, we make a first attempt to analyze L&D in the mountain cryosphere by conducting a systematic literature review to extract L&D impacts and examples from existing literature. We find that L&D is a global phenomenon in the mountain cryosphere and has been more frequently documented in the developing world, both in relation with slow and sudden onset processes. We develop a categorization of L&D, making distinctions between physical and societal impacts, primary and secondary impacts, and identifying seven types of L&D (including L&D to culture, livelihoods, revenue, natural resources, life, and security). We hope this conceptual approach will support future work to understand and address L&D in the mountain cryosphere

Climate trends and glacier retreat in the Cordillera Blanca, Peru, revisited

The total glacial area of the Cordillera Blanca, Peru, has shrunk by more than 30% in the period of 1930 to the present with a marked glacier retreat also in the recent decades. The aim of this paper is to assess local air temperature and precipitation changes in the Cordillera Blanca and to discuss how these variables could have affected the observed glacier retreat between the 1980s and present. A unique data set from a large number of stations in the region of the Cordillera Blanca shows that after a strong air temperature rise of about 0.31 °C per decade between 1969 and 1998, a slowdown in the warming to about 0.13 °C per decade occurred for the 30 years from 1983 to 2012. Additionally, based on data from a long-term meteorological station, it was found that the freezing line altitude during precipitation days has probably not increased significantly in the last 30 years. We documented a cooling trend for maximum daily air temperatures and an increase in precipitation of about 60 mm/decade since the early 1980s. The strong increase in precipitation in the last 30 years probably did not balance the increase of temperature before the 1980s. It is suggested that recent changes in temperature and precipitation alone may not explain the glacial recession within the thirty years from the early 1980s to 2012. Glaciers in the Cordillera Blanca may be still reacting to the positive air temperature rise before 1980. Especially small and low-lying glaciers are characterised by a serious imbalance and may disappear in the near future