A nucleolar protein related to ribosomal protein L7 is required for an early step in large ribosomal subunit biogenesis

The Saccharomyces cerevisiae Rlp7 protein has extensive identity and similarity to the large ribosomal subunit L7 proteins and shares an RNA-binding domain with them. Rlp7p is not a ribosomal protein; however, it is encoded by an essential gene and therefore must perform a function essential for cell growth. In this report, we show that Rlp7p is a nucleolar protein that plays a critical role in processing of precursors to the large ribosomal subunit RNAs. Pulse–chase labeling experiments with Rlp7p-depleted cells reveal that neither 5.8SS, 5.8SL, nor 25S is produced, indicating that both the major and minor processing pathways are affected. Analysis of processing intermediates by primer extension indicates that Rlp7p-depleted cells accumulate the 27SA3 precursor RNA, which is normally the major substrate (85%) used to produce the 5.8S and 25S rRNAs, and the ratio of 27SBL to 27SBS precursors changes from approximately 1:8 to 8:1 (depleted cells). Because 27SA3 is the direct precursor to 27SBS, we conclude that Rlp7p is specifically required for the 5′ to 3′ exonucleolytic trimming of the 27SA3 into the 27SBS precursor. As it is essential for processing in both the major and minor pathways, we propose that Rlp7p may act as a specificity factor that binds precursor rRNAs and tethers the enzymes that carry out the early 5′ to 3′ exonucleolytic reactions that generate the mature rRNAs. Rlp7p may also be required for the endonucleolytic cleavage in internal transcribed spacer 2 that separates the 5.8S rRNA from the 25S rRNA.

Differential Control of Xanthophylls and Light-Induced Stress Proteins, as Opposed to Light-Harvesting Chlorophyll a/b Proteins, during Photosynthetic Acclimation of Barley Leaves to Light Irradiance

Barley (Hordeum vulgare L.) plants were grown at different photon flux densities ranging from 100 to 1800 μmol m−2 s−1 in air and/or in atmospheres with reduced levels of O2 and CO2. Low O2 and CO2 partial pressures allowed plants to grow under high photosystem II (PSII) excitation pressure, estimated in vivo by chlorophyll fluorescence measurements, at moderate photon flux densities. The xanthophyll-cycle pigments, the early light-inducible proteins, and their mRNA accumulated with increasing PSII excitation pressure irrespective of the way high excitation pressure was obtained (high-light irradiance or decreased CO2 and O2 availability). These findings indicate that the reduction state of electron transport chain components could be involved in light sensing for the regulation of nuclear-encoded chloroplast gene expression. In contrast, no correlation was found between the reduction state of PSII and various indicators of the PSII light-harvesting system, such as the chlorophyll a-to-b ratio, the abundance of the major pigment-protein complex of PSII (LHCII), the mRNA level of LHCII, the light-saturation curve of O2 evolution, and the induced chlorophyll-fluorescence rise. We conclude that the chlorophyll antenna size of PSII is not governed by the redox state of PSII in higher plants and, consequently, regulation of early light-inducible protein synthesis is different from that of LHCII.

Sahara Desert, Northwest Africa, 1862 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Itinéraires suivis par les voyages Français et autres qui ont pénétré dans le Sahara, gravé chez Erhard. It was published by Imp-Janson in 1862. Scale 1:20,000,000. Map in French. Covers portions of the Sahara Desert, Northwest Africa. The image inside the map neatline is georeferenced to the surface of the earth and fit to the 'World Polyconic' projection. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, expedition routes, and more. Includes index of exploration routes. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.

Barre, Massachusetts 15 Minute Digital Raster Graphic

This layer is a digital raster graphic of the historic 15-minute USGS topographic quadrangle map of Barre, Massachusetts. The suvery (ground condition) date is 1887, the edition date is March, 1894 and the map was reprinted in 1942. A digital raster graphic (DRG) is a scanned image of a U.S. Geological Survey (USGS) standard series topographic map, including all map collar information. The image inside the map neatline is geo-referenced to the surface of the earth and fit to the Universal Transverse Mercator projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map. The names of quadrangles which border this one appear on the map collar in their respective positions (N,S,E,W) in relation to this map.

Brookfield, Massachusetts 15 Minute Digital Raster Graphic

This layer is a digital raster graphic of the historic 15-minute USGS topographic map of the Brookfield, Massachusetts quadrangle. The survey date (ground condition) of this map is 1886-1887, the edition date is April, 1893 and the map was reprinted in 1942. A digital raster graphic (DRG) is a scanned image of a U.S. Geological Survey (USGS) standard series topographic map, including all map collar information. The image inside the map neatline is geo-referenced to the surface of the earth and fit to the Universal Transverse Mercator projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map. The names of quadrangles which border this one appear on the map collar in their respective positions (N,S,E,W) in relation to this map.

Franklin, Massachusetts 15 Minute Digital Raster Graphic

This layer is a digital raster graphic of the historic 15-minute USGS topographic map of the Franklin, Massachusetts quadrangle. The survey date (ground condition) of the original paper map is 1887, the edition date is August, 1893 and it was reprinted in January 1898. A digital raster graphic (DRG) is a scanned image of a U.S. Geological Survey (USGS) standard series topographic map, including all map collar information. The image inside the map neatline is geo-referenced to the surface of the earth and fit to the Universal Transverse Mercator projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map. The names of quadrangles which border this one appear on the map collar in their respective positions (N,S,E,W) in relation to this map.

Greylock, Massachusetts 15 Minute Digital Raster Graphic

This layer is a digital raster graphic of the historic 15-minute USGS topographic map of the Greylock, Massachusetts quadrangle. The survey date (ground condition) of the original paper map is 1885, the edition date is November, 1898 and it was reprinted in July, 1901. A digital raster graphic (DRG) is a scanned image of a U.S. Geological Survey (USGS) standard series topographic map, including all map collar information. The image inside the map neatline is geo-referenced to the surface of the earth and fit to the Universal Transverse Mercator projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map. The names of quadrangles which border this one appear on the map collar in their respective positions (N,S,E,W) in relation to this map.

Lawrence, Massachusetts 15 Minute Digital Raster Graphic

This layer is a digital raster graphic of the historic 15-minute USGS topographic map of the Lawrence, Massachusetts quadrangle. The survey date (ground condition) of the original paper map is 1886, the edition date is April, 1893 and this map has a reprint date of 1839. A digital raster graphic (DRG) is a scanned image of a U.S. Geological Survey (USGS) standard series topographic map, including all map collar information. The image inside the map neatline is geo-referenced to the surface of the earth and fit to the Universal Transverse Mercator projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map.

Providence, Rhode Island 15 Minute Digital Raster Graphic

This layer is a digital raster graphic of the historic 15-minute USGS topographic map of the Providence, Rhode Island quadrangle which includes areas in the state of Massachusetts. The survey dates (ground condition) of the original paper map are 1885 and 1887, the edition date is February, 1894 and this map has a reprint date of October, 1911. A digital raster graphic (DRG) is a scanned image of a U.S. Geological Survey (USGS) standard series topographic map, including all map collar information. The image inside the map neatline is geo-referenced to the surface of the earth and fit to the Universal Transverse Mercator projection. The horizontal positional accuracy and datum of the DRG matches the accuracy and datum of the source map.

Gold Company Claims, Witwatersrand, South Africa, 1895 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Bacon's new map of the Witwatersrand goldfields in the districts of Pretoria and Heidelberg, Transvaal, S. A. R. : shewing the main and other reefs, with the farms, gold mining company's claims and concessions : from information in the Surveyor-General's Department. It was published by G. W. Bacon & Co. in 1895. Scale [ca. 1:88,992].The image inside the map neatline is georeferenced to the surface of the earth and fit to the Universal Transverse Mercator (UTM Zone 35S, meters, WGS 1984) projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, roads, railroads, cities and other human settlements, administrative boundaries, farms, homesteads, main reefs, other reefs, probable connections, and mills. Includes also notes and inset: "Enlarged map of the farms Lanlaagte, Turffontein, Dornfontein & Elandsfontein, shewing the boundaries of the principal deep level gold mining coys. on the Witwatersrand goldfields" and a geological profile of the area north of Magaliesberg to the south of Witwatersrange.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

North Africa or Barbary

I. Marocco (Scale [ca. 1:2,800,000]) -- II. Algier (Scale [ca. 1:2,000,000]) -- III. Tunis and part of Tripoli (Scale [ca. 1:2,000,000]) -- IV. Tripoli (Scale [ca. 1:2,000,000]) -- V. Parts of Tripoli and Egypt (Scale [ca. 1:2,000,000]).

"Creeping" civil war in the North Caucasus. OSW Commentary No. 50, 2011-03-15

Over the last year, the situation in Russia’s North Caucasus has become further destabilised. Attacks and armed clashes happen daily, and destabilisation is spreading to an increasingly large area. The extent of violence in the region is so great that it can already be stated that a de facto civil war is taking place, the warring parties being the Islamic armed underground movement which operates under the banner of the so-called Emirate of the North Caucasus, and the secular governments of the individual republics, who are supported by local and federal branches of the Russian Federation’s Interior Ministry and Federal Security Service. Moscow has no idea how to successfully tackle the Caucasus rebellion. Force has proved to be costly and unproductive, while the attempts made since early 2010 to integrate the region with the rest of Russia by implementing development programmes have not brought the desired results, because of widespread corruption and faint interest from businessmen who are afraid to invest in such an unsafe region. A growing problem for Moscow, particularly for the prestige of the state, is attacks by militants on areas near Sochi, where the 2014 Winter Olympics is to take place. It must be assumed that over the next 3 years before the Olympics, Moscow’s priority in the region will be to ensure the safety of Olympic preparations, and then the games themselves. It cannot be ruled out that the North Caucasus Federal District with its ‘troubled republics’ will be surrounded by a kind of cordon sanitaire (Sochi is situated in the neighbouring Southern Federal District). This could in turn strengthen these republics’ isolation, maintain the state of permanent instability, and postpone the prospects of solving the region’s acute economic and social problems.

Five things we need to know about the on-demand economy. CEPS Essay No. 21/8 January 2016

The last few years have witnessed the exponential growth of platforms like Uber and Airbnb and the creation of countless other less well-known examples. The expansion of the on-demand economy puts huge pressure on regulators to adapt it to the existing frameworks for labour and taxation. The rapid growth of the sector also divides experts: it is seen by many as threat for working conditions, and by others as an incredible opportunity. The purpose of this essay is to take a balanced perspective on what we know about the on-demand economy and what needs further investigation. More research is needed on the individual cases before one can draw conclusions on how this new sector works. The political economy of the sector is made even more interesting by the fact that the technology is developing faster than the regulation. Yet, our plea to policy-makers is to refrain from legislating too early and to take the time to understand how the supply and the demand of these services behave and their equilibrium.

Benthic oxygen isotope and dust flux record from ODP Site 108-659 in the North Atlantic

High-resolution benthic oxygen isotope and dust flux records from Ocean Drilling Program site 659 have been analyzed to extend the astronomically calibrated isotope timescale for the Atlantic from 2.85 Ma back to 5 Ma. Spectral analysis of the delta18O record indicates that the 41-kyr period of Earth's orbital obliquity dominates the Pliocene record. This is shown to be true regardless of fundamental changes in the Earth's climate during the Pliocene. However, the cycles of Sahelian aridity fluctuations indicate a shift in spectral character near 3 Ma. From the early Pliocene to 3 Ma, the periodicities were dominantly precessional (19 and 23 kyr) and remained strong until 1.5 Ma. Subsequent to 3 Ma, the variance at the obliquity period (41 kyr) increased. The timescale tuned to precession suggests that the Pliocene was longer than previously estimated by more than 0.5 m.y. The tuned ages for the magnetic boundaries Gauss/Gilbert and Top Cochiti are about 6-8% older than the ages of the conventional timescale. A major phase of Pliocene northern hemisphere ice growth occurred between 3.15 Ma and 2.5 Ma. This was marked by a gradual increase in glacial Atlantic delta18O values of 1per mil and an increase in amplitude variations by up to 1.5 per mil, much larger than in the Pacific deepwater record (site 846). The first maxima occured in cold stages G6-96 between 2.7 Ma and 2.45 Ma. Prior to 3 Ma, the isotope record is characterized by predominantly low amplitude fluctuations (< 0.7 per mil). When obliquity forcing was at its minimum between 4.15 and 3.6 Ma and during the Kaena interval, delta18O amplitude fluctuations were minimal. From 4.9 to 4.3 Ma, the delta18O values decreased by about 0.5 per mil, reaching a long-term minimum at 4.15 Ma, suggesting higher deepwater temperatures or a deglaciation. Deepwater cooling and/or an increase in ice volume is indicated by a series of short-term delta18O fluctuations between 3.8 and 3.6 Ma.

Occurrence of planktic foraminifera in Pliocene to Holocene sediments of DSDP Hole 81-552A in the North Atlantic (Appendix 2)

A new planktic foraminifer transfer function (GSF18) related 5 North Atlantic assemblages to winter and summer sea surface temperature. GSF18, based on recombined and simplified core top census data, preserves most environmental information and reproduces modern North Atlantic conditions with approximately the same accuracy as previous transfer functions, but can be more readily applied to faunal samples ranging in age from Pliocene to Holocene. Transfer function GSF18 has been applied to faunal data from Deep Sea Drilling Project Hole 552A to produce a 2.5 m.y. sea-surface temperature (SST) time series. Estimates show several periods between 2.3 and 4.6 Ma during which mean SST's were both several degrees warmer and several degrees cooler than modern conditions. Between 2.9 and 4.0 Ma SST was generally warmer than modern except for a 250 k.y. interval centered at 3.3 Ma. Maximum SST, with respect to modern conditions, occurred after the cool interval near 3.1 Ma when SST was approximately 3.6° C warmer than present conditions. Comparison of SST estimates with stable isotope data suggest that after peak warming at 3.1 Ma, there was an overall surface water cooling with concomitant build up of global ice volume, culminating in Northern Hemisphere glaciation. This event is also indicated by the presence of ice rafted detritus in 552A sediments at about 2.45 Ma.