ALBERT

Description: Energy & Fuels DOI: 10.1021/ef300515q

Description: Energy & Fuels DOI: 10.1021/ef201853k

Description: Ice sheet mass balance estimates have improved substantially in recent years using a variety of techniques, over different time periods, and at various levels of spatial detail. Considerable disparity remains between these estimates due to the inherent uncertainties of each method, the lack of detailed comparison between independent estimates, and the effect of temporal modulations in ice sheet surface mass balance. Here, we present a consistent record of mass balance for the Greenland and Antarctic ice sheets over the past two decades, validated by the comparison of two independent techniques over the last 8 years: one differencing perimeter loss from net accumulation, and one using a dense time series of time-variable gravity. We find excellent agreement between the two techniques for absolute mass loss and acceleration of mass loss. In 2006, the Greenland and Antarctic ice sheets experienced a combined mass loss of 475 ± 158 Gt/yr, equivalent to 1.3 ± 0.4 mm/yr sea level rise. Notably, the acceleration in ice sheet loss over the last 18 years was 21.9 ± 1 Gt/yr2 for Greenland and 14.5 ± 2 Gt/yr2 for Antarctica, for a combined total of 36.3 ± 2 Gt/yr2. This acceleration is 3 times larger than for mountain glaciers and ice caps (12 ± 6 Gt/yr2). If this trend continues, ice sheets will be the dominant contributor to sea level rise in the 21st century.

Description: Energy & Fuels DOI: 10.1021/ef402057w

Description: We review the sea-level and energy budgets together from 1961, using recent and updated estimates of all terms. From 1972 to 2008, the observed sea-level rise (1.8 ± 0.2 mm yr−1 from tide gauges alone and 2.1 ± 0.2 mm yr−1 from a combination of tide gauges and altimeter observations) agrees well with the sum of contributions (1.8 ± 0.4 mm yr−1) in magnitude and with both having similar increases in the rate of rise during the period. The largest contributions come from ocean thermal expansion (0.8 mm yr−1) and the melting of glaciers and ice caps (0.7 mm yr−1), with Greenland and Antarctica contributing about 0.4 mm yr−1. The cryospheric contributions increase through the period (particularly in the 1990s) but the thermosteric contribution increases less rapidly. We include an improved estimate of aquifer depletion (0.3 mm yr−1), partially offsetting the retention of water in dams and giving a total terrestrial storage contribution of −0.1 mm yr−1. Ocean warming (90% of the total of the Earth's energy increase) continues through to the end of the record, in agreement with continued greenhouse gas forcing. The aerosol forcing, inferred as a residual in the atmospheric energy balance, is estimated as −0.8 ± 0.4 W m−2 for the 1980s and early 1990s. It increases in the late 1990s, as is required for consistency with little surface warming over the last decade. This increase is likely at least partially related to substantial increases in aerosol emissions from developing nations and moderate volcanic activity.

Description: Energy & Fuels DOI: 10.1021/ef201551m

Description: Foehn events over the McMurdo Dry Valleys (MDVs), the largest ice-free region of Antarctica, promote glacial melt that supports biological activity in the lakes, streams, rocks and soils. Although MDVs foehn events are known to depend upon the synoptic-scale circulation, the physical processes responsible for foehn events are unknown. A polar-optimized version of the Weather Research and Forecasting model (Polar WRF) is used for a case study of a representative summer foehn event from 29 December 2006 to 1 January 2007 in order to identify and explain the MDVs foehn mechanism. Pressure differences across an elevated mountain gap upstream of the MDVs provide forcing for southerly flow into the western, upvalley entrance of the MDVs. Complex terrain over the elevated gap and the MDVs leads to mountain wave effects such as leeside acceleration, hydraulic jumps, wave breaking and critical layers. These mountain wave effects depend on the ambient (geostrophic) wind direction. Pressure-driven channelling then brings the warm, dry foehn air downvalley to eastern MDV sites. Brief easterly intrusions of maritime air into the eastern MDVs during foehn events previously have been attributed to either a sea-breeze effect in summer or local cold-pooling effects in winter. In this particular case, the easterly intrusions result from blocking effects of nearby Ross Island and the adjacent Antarctic coast. Temperature variability during the summer foehn event, which is important for meltwater production and biological activity when it exceeds 0°C, primarily depends on the source airmass rather than differences in foehn dynamics. Copyright © 2012 Royal Meteorological Society

Description: [1]  High spatial resolution urban climate modeling is essential for understanding urban climatology and predicting the human health impacts under climate change. Satellite thermal remote sensing data are potential observational sources for urban climate model validation with comparable spatial scales, temporal consistency, broad coverage, and long-term archives. However, sensor view angle, cloud distribution, and cloud contaminated pixels can confound comparisons between satellite land surface temperature (LST) and modeled surface radiometric temperature. The impacts of sensor view angles on urban LST values are investigated and addressed. Three methods to minimize the confounding factors of clouds are proposed and evaluated using ten years of Moderate Resolution Imaging Spectroradiometer (MODIS) data and simulations from the High-Resolution Land Data Assimilation System (HRLDAS) over Greater Houston, Texas, USA. For the satellite cloud mask (SCM) method, prior to comparison, the cloud mask for each MODIS scene is applied to its concurrent HRLDAS simulation. For the max/min temperature (MMT) method, the 50 warmest days and coolest nights for each dataset are selected and compared to avoid cloud impacts. For the high clear-sky fraction (HCF) method, only those MODIS scenes that have a high percentage of clear-sky pixels are compared. The SCM method is recommended for validation of long-term simulations because it provides the largest sample size as well as temporal consistency with the simulations. The MMT method is best for comparison at the extremes. And the HCF method gives the best absolute temperature comparison due to the spatial and temporal consistency between simulations and observations.

Description: Small (〈200 nucleotide) RNA (sRNA) profiling of human cells using various technologies demonstrates unexpected complexity of sRNAs with hundreds of thousands of sRNA species present. Genetic and in vitro studies show that these RNAs are not merely degradation products of longer transcripts but could indeed have a function. Furthermore, profiling of RNAs, including the sRNAs, can reveal not only novel transcripts, but also make clear predictions about the existence and properties of novel biochemical pathways operating in a cell. For example, sRNA profiling in human cells indicated the existence of an unknown capping mechanism operating on cleaved RNA, a biochemical component of which was later identified. Here we show that human cells contain a novel type of sRNA that has non-genomically encoded 5' poly(U) tails. The presence of these RNAs at the termini of genes, specifically at the very 3' ends of known mRNAs, strongly argues for the presence of a yet uncharacterized endogenous biochemical pathway in cells that can copy RNA. We show that this pathway can operate on multiple genes, with specific enrichment towards transcript-encoding components of the translational machinery. Finally, we show that genes are also flanked by sense, 3' polyadenylated sRNAs that are likely to be capped.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3058539/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3058539/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kapranov, Philipp -- Ozsolak, Fatih -- Kim, Sang Woo -- Foissac, Sylvain -- Lipson, Doron -- Hart, Chris -- Roels, Steve -- Borel, Christelle -- Antonarakis, Stylianos E -- Monaghan, A Paula -- John, Bino -- Milos, Patrice M -- GM079756/GM/NIGMS NIH HHS/ -- MH60774/MH/NIMH NIH HHS/ -- R01 GM079756/GM/NIGMS NIH HHS/ -- R01 GM079756-01A1/GM/NIGMS NIH HHS/ -- R01 GM079756-02/GM/NIGMS NIH HHS/ -- R01 GM079756-03/GM/NIGMS NIH HHS/ -- R01 HG005230/HG/NHGRI NIH HHS/ -- England -- Nature. 2010 Jul 29;466(7306):642-6. doi: 10.1038/nature09190.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Helicos BioSciences Corporation, 1 Kendall Sq. Ste B7301 Cambridge, Massachusetts 02139-1671, USA. philippk08@gmail.com〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20671709" target="_blank"〉PubMed〈/a〉

Description: Legumes (Fabaceae or Leguminosae) are unique among cultivated plants for their ability to carry out endosymbiotic nitrogen fixation with rhizobial bacteria, a process that takes place in a specialized structure known as the nodule. Legumes belong to one of the two main groups of eurosids, the Fabidae, which includes most species capable of endosymbiotic nitrogen fixation. Legumes comprise several evolutionary lineages derived from a common ancestor 60 million years ago (Myr ago). Papilionoids are the largest clade, dating nearly to the origin of legumes and containing most cultivated species. Medicago truncatula is a long-established model for the study of legume biology. Here we describe the draft sequence of the M. truncatula euchromatin based on a recently completed BAC assembly supplemented with Illumina shotgun sequence, together capturing approximately 94% of all M. truncatula genes. A whole-genome duplication (WGD) approximately 58 Myr ago had a major role in shaping the M. truncatula genome and thereby contributed to the evolution of endosymbiotic nitrogen fixation. Subsequent to the WGD, the M. truncatula genome experienced higher levels of rearrangement than two other sequenced legumes, Glycine max and Lotus japonicus. M. truncatula is a close relative of alfalfa (Medicago sativa), a widely cultivated crop with limited genomics tools and complex autotetraploid genetics. As such, the M. truncatula genome sequence provides significant opportunities to expand alfalfa's genomic toolbox.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3272368/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3272368/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Young, Nevin D -- Debelle, Frederic -- Oldroyd, Giles E D -- Geurts, Rene -- Cannon, Steven B -- Udvardi, Michael K -- Benedito, Vagner A -- Mayer, Klaus F X -- Gouzy, Jerome -- Schoof, Heiko -- Van de Peer, Yves -- Proost, Sebastian -- Cook, Douglas R -- Meyers, Blake C -- Spannagl, Manuel -- Cheung, Foo -- De Mita, Stephane -- Krishnakumar, Vivek -- Gundlach, Heidrun -- Zhou, Shiguo -- Mudge, Joann -- Bharti, Arvind K -- Murray, Jeremy D -- Naoumkina, Marina A -- Rosen, Benjamin -- Silverstein, Kevin A T -- Tang, Haibao -- Rombauts, Stephane -- Zhao, Patrick X -- Zhou, Peng -- Barbe, Valerie -- Bardou, Philippe -- Bechner, Michael -- Bellec, Arnaud -- Berger, Anne -- Berges, Helene -- Bidwell, Shelby -- Bisseling, Ton -- Choisne, Nathalie -- Couloux, Arnaud -- Denny, Roxanne -- Deshpande, Shweta -- Dai, Xinbin -- Doyle, Jeff J -- Dudez, Anne-Marie -- Farmer, Andrew D -- Fouteau, Stephanie -- Franken, Carolien -- Gibelin, Chrystel -- Gish, John -- Goldstein, Steven -- Gonzalez, Alvaro J -- Green, Pamela J -- Hallab, Asis -- Hartog, Marijke -- Hua, Axin -- Humphray, Sean J -- Jeong, Dong-Hoon -- Jing, Yi -- Jocker, Anika -- Kenton, Steve M -- Kim, Dong-Jin -- Klee, Kathrin -- Lai, Hongshing -- Lang, Chunting -- Lin, Shaoping -- Macmil, Simone L -- Magdelenat, Ghislaine -- Matthews, Lucy -- McCorrison, Jamison -- Monaghan, Erin L -- Mun, Jeong-Hwan -- Najar, Fares Z -- Nicholson, Christine -- Noirot, Celine -- O'Bleness, Majesta -- Paule, Charles R -- Poulain, Julie -- Prion, Florent -- Qin, Baifang -- Qu, Chunmei -- Retzel, Ernest F -- Riddle, Claire -- Sallet, Erika -- Samain, Sylvie -- Samson, Nicolas -- Sanders, Iryna -- Saurat, Olivier -- Scarpelli, Claude -- Schiex, Thomas -- Segurens, Beatrice -- Severin, Andrew J -- Sherrier, D Janine -- Shi, Ruihua -- Sims, Sarah -- Singer, Susan R -- Sinharoy, Senjuti -- Sterck, Lieven -- Viollet, Agnes -- Wang, Bing-Bing -- Wang, Keqin -- Wang, Mingyi -- Wang, Xiaohong -- Warfsmann, Jens -- Weissenbach, Jean -- White, Doug D -- White, Jim D -- Wiley, Graham B -- Wincker, Patrick -- Xing, Yanbo -- Yang, Limei -- Yao, Ziyun -- Ying, Fu -- Zhai, Jixian -- Zhou, Liping -- Zuber, Antoine -- Denarie, Jean -- Dixon, Richard A -- May, Gregory D -- Schwartz, David C -- Rogers, Jane -- Quetier, Francis -- Town, Christopher D -- Roe, Bruce A -- BB/G023832/1/Biotechnology and Biological Sciences Research Council/United Kingdom -- BBS/B/11524/Biotechnology and Biological Sciences Research Council/United Kingdom -- England -- Nature. 2011 Nov 16;480(7378):520-4. doi: 10.1038/nature10625.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Plant Pathology, University of Minnesota, St Paul, Minnesota 55108, USA. neviny@umn.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22089132" target="_blank"〉PubMed〈/a〉