oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
PD Trafficking of Potato Leaf Roll Virus Movement Protein in Arabidopsis Depends on Site-specific Protein Phosphorylation  [PDF]
Katrin Link,Uwe Sonnewald
Frontiers in Plant Science , 2011, DOI: 10.3389/fpls.2011.00018
Abstract: Many plant viruses encode for specialized movement proteins (MP) to facilitate passage of viral material to and through plasmodesmata (PD). To analyze intracellular trafficking of potato leaf roll virus (PLRV) movement protein (MP17) we performed GFP fusion experiments with distinct deletion variants of MP17. These studies revealed that the C-terminus of MP17 is essential but not sufficient for PD targeting. Interestingly, fusion of GFP to three C-terminal MP17 deletion variants resulted in the accumulation of GFP in chloroplasts. This indicates that MP17 harbors hidden plastid targeting sequences. Previous studies showed that posttranslational protein phosphorylation influences PD targeting of MP and virus spread. Analysis of MP17-derived phospho-peptides by mass spectrometry revealed four phosphorylated serine residues (S71, S79, S137, and S140). Site-directed mutagenesis of S71/S79 and S137/S140 showed that the C-terminal serine residues S137/S140 are dispensable for PD targeting. However, exchange of S71/S79 to A71/A79 abolished PD targeting of the mutated MP17 protein. To mimic phosphorylation of S71/S79 both amino acids were substituted by aspartic acid. The resulting D71/D79 variant of MP17 was efficiently targeted to PD. Further deletion analysis showed that PD targeting of MP17 is dependent on the C-terminus, phosphorylation of S71 and/or S79 and a N-terminal domain.
Highway Design on the Sections Affected by Aquaplaning Automobili keli ruo projektavimas, vertinant akvaplanavim  [cached]
Aleksandr Reznik,Andrej Beljatynskij
Science – Future of Lithuania , 2009, DOI: 10.3846/mla.2009.6.06
Abstract: Pouring rain, snow melting, water condensing, fog and other natural phenomena cause the collection of water on roadway pavement, leading to the decrease of road-holding capacity of a tyre. When a car or a light truck is moving at a high speed on wet road pavement, the water under its wheels cannot be expelled in time. It results in raising of the front wheels of the vehicle above the road surface under the action of a hydrodynamic force and loss of vehicle control. The methods ensuring traffic safety on road sections, where vehicle’s aquaplaning is possible, should be developed by identifying and improving these sections at the stages of highway design, reconstruction and maintenance and by limiting traffic speed of vehicles. Keywords: vehicle, road, road-holding capacity, aquaplaning, reconstruction, maintenance, traffic safety. DOI: 10.3846/mla.2009.6.06 Lyjant lietui, tirpstant sniegui, esant stipriam rūkui ir pan., kelio dangos pavir iuje susikaupia vandens sluoksnis. Transporto priemonei judant lapia kelio danga dideliu grei iu min tas vanduo ne visada i stumiamas i po transporto priemon s rat padang ir kelio dangos pavir iaus s veikos zonos. Akvaplanavimas – tai rei kinys, kai transporto priemon s ratai praranda sukibim su kelio danga ir skrieja vandens pavir iumi, transporto priemon prakti kai lieka nevaldoma iki tol, kol neprava iuos lapio kelio ruo o. Autoriai analizuoja transporto priemoni saugaus eismo keliais su lapia danga metodus ir aptaria juos automobili keli projektavimo kontekste. Reik miniai od iai: transporto priemon , automobili kelias, kelio danga, vanduo, akvaplanavimas, sukibimas. DOI: 10.3846/mla.2009.6.06 Александр Резник, Андрей Белятынский. Проектирование автодорог на отрезках, подверженных влиянию аквапланирования // MOKSLAS – LIETUVOS ATEITIS. Vilnius: Technika, 2009, t. 1, Nr. 6 , p. 29-32. Аннотация. Во время ливня, таяния снега, конденсации воды, при туманах и некоторых других погодных явлениях на покрытии автодороги соб
Of Winds and Waves  [PDF]
John G. Kirk,Ioanna Arka
Physics , 2011,
Abstract: Recent work on the properties of superluminal waves in pulsar winds is summarized. It is speculated that these waves play an important role in the termination shock that divides the wind from the surrounding nebula.
Modelling the dynamics of turbulent floods  [PDF]
Z. Mei,A. J. Roberts,Zhenquan Li
Physics , 1999,
Abstract: Consider the dynamics of turbulent flow in rivers, estuaries and floods. Based on the widely used k-epsilon model for turbulence, we use the techniques of centre manifold theory to derive dynamical models for the evolution of the water depth and of vertically averaged flow velocity and turbulent parameters. This new model for the shallow water dynamics of turbulent flow: resolves the vertical structure of the flow and the turbulence; includes interaction between turbulence and long waves; and gives a rational alternative to classical models for turbulent environmental flows.
Extreme flash floods in Barcelona County
A. Barrera, M. Barriendos,M. C. Llasat
Advances in Geosciences (ADGEO) , 2005,
Abstract: In this paper the catastrophic and extraordinary floods occurring in Barcelona County (Catalonia, NE Spain) are studied, in order to characterise the temporal evolution of extreme flash floods in that area and their main features. These events usually cause economical losses and major problems for undertaking daily activity in Barcelona city. This kind of floods is a very common feature in the North-east of Spain and they are recorded every year in some point of Catalonia. This contribution also shows the frequency of those events, within the framework of all the floods that have occurred in Barcelona since the 14th century, but also describes the flooded area, urban evolution, impacts and the weather conditions for any of most severe events. The evolution of flood occurrence shows the existence of oscillations in the earlier and later modern age periods that can be attributed to climatic variability, evolution of the perception threshold and changes in vulnerability. A great increase of vulnerability can be assumed for the period 1850-1900. The analysis of the time evolution for the Barcelona rainfall series (1854-2000) shows that no trend exists, although, due to the changes in urban planning, flash-floods impact has changed over this time. The number of catastrophic flash floods has diminished, although the extraordinary ones have increased.
FLASH FLOODS IN THE ILI UA BASIN  [PDF]
G. HOGNOGI,G. NICULA,GABRIELA COCEAN
Aerul ?i Apa : Componente ale Mediului , 2011,
Abstract: Flash Floods in the Ili ua Basin. The Ili ua Valley is a right tributary of the Some u Mare Valley and has its spring in the south-western part of the Tible Mountains. It is a perennial river, and its maximum flow sometimes exceeds the national multi-anual average. One manifestation of this high flow is represented by two types of flash floods: the ones caused by heavy rainfall and the ones caused by the both heavy precipitation and the melting of snow. These two types of flash floods have specific characteristics not only in terms of causes but also in the happening, the impact area and the scale or proportions of damage. These features are further explained in the analysis of two flash floods that have taken place on May 12-17, 1970 and June 20-21, 2006. The occurence of these extreme hydrological phenomena in the basin and their impact upon nature, people and infrastructure makes the need of more hydrological survey a fact.
Improvement on NaOCl Method Used for the Liable_to_roll_up Leaf Epidermis
易卷曲叶表皮制片技术(NaOCl法)的改进

洪亚平,陈之端
植物学报 , 2002,
Abstract: As we prepare the leaf epidermis for examination under light microscopy using the traditional NaOCl method, sometimes difficulties occur in some materials from different families or genera in which the epidermis rolls up easily after dehydration with 100% Ethanol. This paper introduced a method by using a small piece of cover_glass to cover the epidermis before washing it with Xylene, this way the epidermis could maintain open and flat. The improvement made the technique of epidermal preparation based on NaOCl method more perfect.
Floods of Fury in Nigerian Cities  [cached]
Odufuwa Bashir O.,Adedeji Oludare H.,Oladesu Johnson O.,Bongwa Aloysius
Journal of Sustainable Development , 2012, DOI: 10.5539/jsd.v5n7p69
Abstract: Flooding is a phenomenon that sometimes has devastating effects on human livelihoods. Impact of floods is more pronounced in low-lying areas due to rapid growth in population, poor governance, decaying infrastructure and lack of proper environmental planning and management. Flooding is also exacerbated by climate change and inadequate preparedness. However, flooding in most Nigerian cities is a major environmental challenge that has continued to defy solution as more people are rendered vulnerable to hazards involved. The implications of recent flooding in Nigerian cities include among others; loss of life and properties, spread of diseases, deformed livelihoods, assets and infrastructure. This paper therefore provides an overview of how Nigerian cities have been affected by flood incidences. The paper contends that prevailing effects of climate change, particularly flooding affecting almost everything in cities demands urgent attention in form of environmental and infrastructure planning, effective policy, improved and effective management of ecological fund, enhanced environmental disaster insurance, effective professional practice, enhanced public enlightment programmes, integration of environmental planning and education to curriculum of schools at all levels, capacity building towards adaptation and mitigation of climate change impact. It also argued for the need to reinvent Nigerian cities through good governance towards creating sustainable cities in the country.
Fast-Roll Inflation  [PDF]
Andrei Linde
Physics , 2001, DOI: 10.1088/1126-6708/2001/11/052
Abstract: We show that in the simplest theories of spontaneous symmetry breaking one can have a stage of a fast-roll inflation. In this regime the standard slow-roll condition |m^2| << H^2 is violated. Nevertheless, this stage can be rather long if |m| is sufficiently small. Fast-roll inflation can be useful for generating proper initial conditions for the subsequent stage of slow-roll inflation in the very early universe. It may also be responsible for the present stage of accelerated expansion of the universe. We also make two observations of a more general nature. First of all, the universe after a long stage of inflation (either slow-roll or fast-roll) cannot reach anti-de Sitter regime even if the cosmological constant is negative. Secondly, the theories with the potentials with a "stable" minimum at V(\phi)<0 in the cosmological background exhibit the same instability as the theories with potentials unbounded from below. This instability leads to the development of singularity with the properties practically independent of V(\phi). However, the development of the instability in some cases may be so slow that the theories with the potentials unbounded from below can describe the present stage of cosmic acceleration even if this acceleration occurs due to the fast-roll inflation.
On the Historical Floods in the Lower Reaches of the Jialing River  [PDF]
XIA Xiufang,XU Gang,LIN Zhiyi
Journal of Chongqing Normal University , 2012,
Abstract: The paper analyzes the overview of the flood, the time distribution of floods and the overlay combination rule of floods in the lower reaches of the Jialing River since 773 AD, in the method of historical documents and statistical analysis, referring to historical data and measured data of floods in the lower reaches of the Jialing River. Through the analysis, the author finally draws conclusion: 1) there are 11times of floods in the lower reaches of the Jialing River assured since 1870, among which the floods in 1870, 1903 and 1981 lead the list respectively; 2) The floods in this area have obvious(displays definite) time distribution that the floods occur mainly in June, July , August and September;3) affected by Fu River, Jialing River and Qu River, the waters of all these three rivers can seriously influence the shape of floods in the lower reaches of the Jialing River. Because of the flourishing economy and densely populated towns, strengthening the regional floods’ research has important practical significance which will offer scientific basis for the flood control and disaster alleviation in the area.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.