77 research outputs found
Calibration and application of a hydraulic model for the operation of an irrigation canal: a study in the Chistian Subdivision, Fordwah/Eastern Sadiqia Area, Punjab, Pakistan
Irrigation canals / Hydraulics / Mathematical models / Calibrations / Simulation / Flow control / Irrigation operation / Pakistan / Punjab / Fordwah Eastern Sadiqia Area / Chishtian Sub-Division
Search for microwave emission from ultrahigh energy cosmic rays
We present a search for microwave emission from air showers induced by
ultrahigh energy cosmic rays with the microwave detection of air showers
experiment. No events were found, ruling out a wide range of power flux and
coherence of the putative emission, including those suggested by recent
laboratory measurements.Comment: 5 pages, 3 figure
The MIDAS telescope for microwave detection of ultra-high energy cosmic rays
We present the design, implementation and data taking performance of the
MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view
imaging telescope designed to detect microwave radiation from extensive air
showers induced by ultra-high energy cosmic rays. This novel technique may
bring a tenfold increase in detector duty cycle when compared to the standard
fluorescence technique based on detection of ultraviolet photons. The MIDAS
telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera,
instrumented with feed horns operating in the commercial extended C-Band (3.4
-- 4.2 GHz). A self-trigger capability is implemented in the digital
electronics. The main objectives of this first prototype of the MIDAS telescope
- to validate the telescope design, and to demonstrate a large detector duty
cycle - were successfully accomplished in a dedicated data taking run at the
University of Chicago campus prior to installation at the Pierre Auger
Observatory.Comment: 13 pages, 18 figure
Dimerization-driven interaction of hepatitis C virus core protein with NS3 helicase
Hepatitis C virus (HCV) infects over 130 million people causing a worldwide epidemic of liver cirrhosis and hepatocellular-carcinoma. Because current HCV treatments are only partially effective, molecular mechanisms involved in HCV propagation are actively being pursued as possible drug targets. Here, we report on a new macromolecular interaction between the HCV capsid core protein and the helicase portion of HCV non-structural protein 3 (NS3h), confirmed by four different biochemical methods. The protease portion of NS3 is not required. Interaction between the two proteins could be disrupted by two types of specific inhibitors of core dimerization, the small molecule SL201 and core106, a C-terminally truncated core protein. Cross-linking experiments suggest that the physical interaction with NS3h is probably driven by core oligomerization. Moreover, SL201 blocks the production of infectious virus, but not the production of a subgenomic HCV replicon by hepatoma cells. Time-of-addition experiments confirm that SL201 has no effect on entry of the virus. These data underline the essential role of core as a key organizer of HCV particle assembly, confirm the importance of oligomerization, reveal the interaction with viral helicase and support a new molecular understanding of the formation of the viral particle at the level of the lipid droplets, before its migration to the site of release and budding
Recovery in Stroke Rehabilitation through the Rotation of Preferred Directions Induced by Bimanual Movements: A Computational Study
Stroke patients recover more effectively when they are rehabilitated with bimanual movement rather than with unimanual movement; however, it remains unclear why bimanual movement is more effective for stroke recovery. Using a computational model of stroke recovery, this study suggests that bimanual movement facilitates the reorganization of a damaged motor cortex because this movement induces rotations in the preferred directions (PDs) of motor cortex neurons. Although the tuning curves of these neurons differ during unimanual and bimanual movement, changes in PD, but not changes in modulation depth, facilitate such reorganization. In addition, this reorganization was facilitated only when encoding PDs are rotated, but decoding PDs are not rotated. Bimanual movement facilitates reorganization because this movement changes neural activities through inter-hemispheric inhibition without changing cortical-spinal-muscle connections. Furthermore, stronger inter-hemispheric inhibition between motor cortices results in more effective reorganization. Thus, this study suggests that bimanual movement is effective for stroke rehabilitation because this movement rotates the encoding PDs of motor cortex neurons
Highlights from the Pierre Auger Observatory
The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray
Conference, Rio de Janeiro 201
Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory
The Pierre Auger Collaboration has reported evidence for anisotropy in the
distribution of arrival directions of the cosmic rays with energies
eV. These show a correlation with the distribution
of nearby extragalactic objects, including an apparent excess around the
direction of Centaurus A. If the particles responsible for these excesses at
are heavy nuclei with charge , the proton component of the
sources should lead to excesses in the same regions at energies . We here
report the lack of anisotropies in these directions at energies above
(for illustrative values of ). If the anisotropies
above are due to nuclei with charge , and under reasonable
assumptions about the acceleration process, these observations imply stringent
constraints on the allowed proton fraction at the lower energies
A Concerted Action of Hepatitis C Virus P7 and Nonstructural Protein 2 Regulates Core Localization at the Endoplasmic Reticulum and Virus Assembly
Hepatitis C virus (HCV) assembly remains a poorly understood process. Lipid droplets (LDs) are thought to act as platforms for the assembly of viral components. The JFH1 HCV strain replicates and assembles in association with LD-associated membranes, around which viral core protein is predominantly detected. In contrast, despite its intrinsic capacity to localize to LDs when expressed individually, we found that the core protein of the high-titer Jc1 recombinant virus was hardly detected on LDs of cell culture-grown HCV (HCVcc)-infected cells, but was mainly localized at endoplasmic reticulum (ER) membranes where it colocalized with the HCV envelope glycoproteins. Furthermore, high-titer cell culture-adapted JFH1 virus, obtained after long-term culture in Huh7.5 cells, exhibited an ER-localized core in contrast to non-adapted JFH1 virus, strengthening the hypothesis that ER localization of core is required for efficient HCV assembly. Our results further indicate that p7 and NS2 are HCV strain-specific factors that govern the recruitment of core protein from LDs to ER assembly sites. Indeed, using expression constructs and HCVcc recombinant genomes, we found that p7 is sufficient to induce core localization at the ER, independently of its ion-channel activity. Importantly, the combined expression of JFH1 or Jc1 p7 and NS2 induced the same differential core subcellular localization detected in JFH1- vs. Jc1-infected cells. Finally, results obtained by expressing p7-NS2 chimeras between either virus type indicated that compatibilities between the p7 and the first NS2 trans-membrane domains is required to induce core-ER localization and assembly of extra- and intra-cellular infectious viral particles. In conclusion, we identified p7 and NS2 as key determinants governing the subcellular localization of HCV core to LDs vs. ER and required for initiation of the early steps of virus assembly
Molecular Determinants and Dynamics of Hepatitis C Virus Secretion
The current model of hepatitis C virus (HCV) production involves the assembly of virions on or near the surface of lipid droplets, envelopment at the ER in association with components of VLDL synthesis, and egress via the secretory pathway. However, the cellular requirements for and a mechanistic understanding of HCV secretion are incomplete at best. We combined an RNA interference (RNAi) analysis of host factors for infectious HCV secretion with the development of live cell imaging of HCV core trafficking to gain a detailed understanding of HCV egress. RNAi studies identified multiple components of the secretory pathway, including ER to Golgi trafficking, lipid and protein kinases that regulate budding from the trans-Golgi network (TGN), VAMP1 vesicles and adaptor proteins, and the recycling endosome. Our results support a model wherein HCV is infectious upon envelopment at the ER and exits the cell via the secretory pathway. We next constructed infectious HCV with a tetracysteine (TC) tag insertion in core (TC-core) to monitor the dynamics of HCV core trafficking in association with its cellular cofactors. In order to isolate core protein movements associated with infectious HCV secretion, only trafficking events that required the essential HCV assembly factor NS2 were quantified. TC-core traffics to the cell periphery along microtubules and this movement can be inhibited by nocodazole. Sub-populations of TC-core localize to the Golgi and co-traffic with components of the recycling endosome. Silencing of the recycling endosome component Rab11a results in the accumulation of HCV core at the Golgi. The majority of dynamic core traffics in association with apolipoprotein E (ApoE) and VAMP1 vesicles. This study identifies many new host cofactors of HCV egress, while presenting dynamic studies of HCV core trafficking in infected cells
Identifying clouds over the Pierre Auger Observatory using infrared satellite data
We describe a new method of identifying night-time clouds over the Pierre Auger Observatory using infrared data from the Imager instruments on the GOES-12 and GOES-13 satellites. We compare cloud. identifications resulting from our method to those obtained by the Central Laser Facility of the Auger Observatory. Using our new method we can now develop cloud probability maps for the 3000 km(2) of the Pierre Auger Observatory twice per hour with a spatial resolution of similar to 2.4 km by similar to 5.5 km. Our method could also be applied to monitor cloud cover for other ground-based observatories and for space-based observatories. (C) 2013 Elsevier B.V. All rights reserved.The successful installation, commissioning, and operation of the
Pierre Auger Observatory would not have been possible without
the strong commitment and effort from the technical and adminis-
trative staff in MalargĂŒe.
We are very grateful to the following agencies and organiza-
tions for financial support: ComisiĂłn Nacional de EnergĂa AtĂłmica,
FundaciĂłn Antorchas, Gobierno De La Provincia de Mendoza,
Municipalidad de MalargĂŒe, NDM Holdings and Valle Las Leñas,
in gratitude for their continuing cooperation over land access,
Argentina; the Australian Research Council; Conselho Nacional de
Desenvolvimento CientĂfico e TecnolĂłgico (CNPq), Financiadora
de Estudos e Projetos (FINEP), Fundação de Amparo à Pesquisa do
Estado de Rio de Janeiro (FAPERJ), Fundação de Amparo à Pesquisa
do Estado de SĂŁo Paulo (FAPESP), MinistĂ©rio de CiĂȘncia e Tecnolo-
gia (MCT), Brazil; AVCR AV0Z10100502 and AV0Z10100522, GAAV
KJB100100904, MSMT-CR LA08016, LG11044, MEB111003,
MSM0021620859, LA08015, TACR TA01010517 and GA UK
119810, Czech Republic; Centre de Calcul IN2P3/CNRS, Centre Na-
tional de la Recherche Scientifique (CNRS), Conseil RĂ©gional Ile-de-
France, Département Physique Nucléaire et Corpusculaire (PNC-
IN2P3/CNRS), DĂ©partement Sciences de lâUnivers (SDU-INSU/
CNRS), France; Bundesministerium fĂŒr Bildung und Forschung
(BMBF), Deutsche Forschungsgemeinschaft (DFG), Finanzministeri-
um Baden-WĂŒrttemberg, Helmholtz-Gemeinschaft Deutscher
Forschungszentren (HGF), Ministerium fĂŒr Wissenschaft und
Forschung, Nordrhein-Westfalen, Ministerium fĂŒr Wissenschaft,
Forschung und Kunst, Baden-WĂŒrttemberg, Germany; Istituto
Nazionale di Fisica Nucleare (INFN), Ministero dellâIstruzione,
dellâUniversitĂ e della Ricerca (MIUR), Italy; Consejo Nacional de Ciencia y TecnologĂa (CONACYT), Mexico; Ministerie van Ond-
erwijs, Cultuur en Wetenschap, Nederlandse Organisatie voor Wet-
enschappelijk Onderzoek (NWO), Stichting voor Fundamenteel
Onderzoek der Materie (FOM), Netherlands; Ministry of Science
and Higher Education, Grant Nos. N N202 200239 and N N202
207238, Poland; Portuguese national funds and FEDER funds with-
in COMPETE - Programa Operacional Factores de Competitividade
through Fundação para a CiĂȘncia e a Tecnologia, Portugal; Roma-
nian Authority for Scientific Research ANCS, CNDI-UEFISCDI part-
nership projects nr.20/2012 and nr.194/2012, project nr.1/
ASPERA2/2012 ERA-NET and PN-II-RU-PD-2011-3-0145-17, Roma-
nia; Ministry for Higher Education, Science, and Technology, Slove-
nian Research Agency, Slovenia; Comunidad de Madrid, FEDER
funds, Ministerio de Ciencia e InnovaciĂłn and Consolider-Ingenio
2010 (CPAN), Xunta de Galicia, Spain; The Leverhulme Foundation,
Science and Technology Facilities Council, United Kingdom;
Department of Energy, Contract Nos. DE-AC02-07CH11359, DE-
FR02-04ER41300, DE-FG02-99ER41107, National Science Founda-
tion, Grant No. 0450696, The Grainger Foundation USA; NAFO-
STED, Vietnam; Marie Curie-IRSES/EPLANET, European Particle
Physics Latin American Network, European Union 7th Framework
Program, Grant No. PIRSES-2009-GA-246806; and UNESCO.
We would like to thank the former Michigan Tech students:
Nathan Kelley-Hoskins, Kyle Luck and Arin Nelson for their impor-
tant contribution to the development of this paper. We would like
to thank NOAA for the GOES satellite data that we freely down-
loaded from their website. Also, we would like to mention in these
acknowledgments Dr. Steve Ackerman and Dr. Tony Schreiner for
very valuable conversationsPeer reviewe
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