287 research outputs found
The magnetic connectivity of coronal shocks from behind-the-limb flares to the visible solar surface during -ray events
Context. The observation of >100 MeV {\gamma}-rays in the minutes to hours
following solar flares suggests that high-energy particles interacting in the
solar atmosphere can be stored and/or accelerated for long time periods. The
occasions when {\gamma}-rays are detected even when the solar eruptions
occurred beyond the solar limb as viewed from Earth provide favorable viewing
conditions for studying the role of coronal shocks driven by coronal mass
ejections (CMEs) in the acceleration of these particles.
Aims: In this paper, we investigate the spatial and temporal evolution of the
coronal shocks inferred from stereoscopic observations of behind-the-limb
flares to determine if they could be the source of the particles producing the
{\gamma}-rays.
Methods: We analyzed the CMEs and early formation of coronal shocks
associated with {\gamma}-ray events measured by the Fermi-Large Area Telescope
(LAT) from three eruptions behind the solar limb as viewed from Earth on 2013
Oct. 11, 2014 Jan. 06 and Sep. 01. We used a 3D triangulation technique, based
on remote-sensing observations to model the expansion of the CME shocks from
above the solar surface to the upper corona. Coupling the expansion model to
various models of the coronal magnetic field allowed us to derive the
time-dependent distribution of shock Mach numbers and the magnetic connection
of particles produced by the shock to the solar surface visible from Earth.
Results: The reconstructed shock fronts for the three events became
magnetically connected to the visible solar surface after the start of the
flare and just before the onset of the >100 MeV {\gamma}-ray emission. The
shock surface at these connections also exhibited supercritical Mach numbers
required for significant particle energization.
[...] (Abridged)Comment: 20 pages, 15 figures, version published in A&
Diagnosticul modificărilor morfologice ale parenchimului renal în hidronefroză la copii prin puncţie-biopsie
Summary
The authors present the results of the morphologic study of kidney
parenchyma’s pathologic modifications in 16 children with hydronephrosis through puncture-biopsy (Bard Magnum Biopsy System).
In conclusion the puncture-biopsy method can be used to determine the disease clinical phase, as well as to reveal some pathogenetic mechanisms that allows by the aim of organ preservation the
surgical tactics optimization and postoperative treatment adjustment.
Introducere. Diagnosticul modificărilor morfologice în
parenchimul renal, în cadrul hidronefrozei la copii, se bazează
pe evaluarea leziunilor structurale care în mare măsură depind
de diversitatea factorilor etiologici.
Material şi metode. Studiul morfologic întreprins a avut
ca scop elucidarea modificărilor morfologice ale parenchimului
renal prin puncţie-biopsie efectuate cu Bard Magnum Biopsy
System. Au fost studiate bioptate ale parenchimului renal la 16
copii cu hidronefroză. Bioptatele au fost fixate în sol. Formol
neutru 4 şi 10%, incluse ulterior în parafină. Au fost utilizate
coloraţiile hematoxilină-eozină, van Ghieson, Congo red.
Rezultate şi concluzii. Examenul efectuat la microsocpia optică
a evidenţiat modificări variate în toate componentele nefronului şi
ale structurilor interstiţial-vasculare de intensitate şi de origine diversă: dilatativ-compresive - ectazie generalizată, leziuni
ischemico-sclerotice şi atrofico-deformative; obstructive - de tip
„hidronefroză intrarenală", transformare tubulară pseudochistică,
displazice - imaturitate şi mostruozităţi glomerulare, polimorfism
structural, oligoglomerulonefronie, multiglomerularitate;
inflamatorii - tubulo-interstiţiale, peri- şi intraglomerulare exudativalterative, polimorfocelulare şi infiltrativ sclerotice; stenoze
vasculare, hipertrofice şi sclerozante, depozite calcinoase
postischemice etc. Caracterul, gradul lezional şi complexitatea
morfologică a modificărilor în parenchimul renal pun în evidenţă
două variante histopatologice: varaianta complicată şi pe cea
necomplicată. Referitor la evoluţia modificărilor morfopatologice
în parenchimul renal, acesta suportă 2 faze succesive: faza de
ectazie şi faza de atrofie. De menţionat că prezenţa elementului
inflamator este determinantă în morfogeneza dereglărilor
funcţionale renale în cadrul variantei complicate.
Aşadar, diagnosticul prin puncţie-biopsie în hidronefroză
poate fi utilizat în aprecierea variantelor patologice şi a fazelor
clinico-evolutive, a studiului unor verigi etiopatogenetice ale
maladiei, ceea ce ar permite soluţionarea problemei în vederea
păstrării organului, precum şi determinarea conduitei în perioada
postoperatorie
Recommended from our members
Orthographic facilitation in oral vocabulary acquisition
An experiment investigated whether exposure to orthography facilitates oral vocabulary learning. A total of 58 typically developing children aged 8-9 years were taught 12 nonwords. Children were trained to associate novel phonological forms with pictures of novel objects. Pictures were used as referents to represent novel word meanings. For half of the nonwords children were additionally exposed to orthography, although they were not alerted to its presence, nor were they instructed to use it. After this training phase a nonword-picture matching posttest was used to assess learning of nonword meaning, and a spelling posttest was used to assess learning of nonword orthography. Children showed robust learning for novel spelling patterns after incidental exposure to orthography. Further, we observed stronger learning for nonword-referent pairings trained with orthography. The degree of orthographic facilitation observed in posttests was related to children's reading levels, with more advanced readers showing more benefit from the presence of orthography
Chloride anion transporters inhibit growth of methicillin-resistant: Staphylococcus aureus (MRSA) in vitro
A series of aminopyrrolic receptors were tested as anion transporters using POPC liposome model membranes. Many were found to be effective Cl(−) transporters and to inhibit clinical strains of Staphylococcus aureus growth in vitro. The best transporters proved effective against the methicillin-resistant Staphylococcus aureus (MRSA) strains, Mu50 and HP1173. Tris-thiourea tren-based chloride transporters were also shown to inhibit the growth of S. aureus. in vitro
Chloride anion transporters inhibit growth of methicillin-resistant Staphylococcus aureus (MRSA) in vitro
A series of aminopyrrolic receptors were tested as anion transporters using POPC liposome model membranes. Many were found to be effective Cl– transporters and to inhibit clinical strains of Staphylococcus aureus growth in vitro. The best transporters proved effective against the methicillin-resistant Staphylococcus aureus (MRSA) strains, Mu50 and HP1173. Tris-thiourea tren-based chloride transporters were also shown to inhibit the growth of S. aureus. in vitro.<br/
Supersymmetry and the relationship between a class of singular potentials in arbitrary dimensions
The eigenvalues of the potentials
and
, and of the special cases of these potentials such as the Kratzer and
Goldman-Krivchenkov potentials, are obtained in N-dimensional space. The
explicit dependence of these potentials in higher-dimensional space is
discussed, which have not been previously covered.Comment: 13 pages article in LaTEX (uses standard article.sty). Please check
"http://www1.gantep.edu.tr/~ozer" for other studies of Nuclear Physics Group
at University of Gaziante
Immediate pre-meal water ingestion decreases voluntary food intake in lean young males
Purpose: Consuming 375-500 ml of water 30 min before a meal has been shown to reduce energy intake in older, but not younger adults. This study investigated the effects of ingesting a water preload immediately pre-meal (<1 min before eating) on within-meal ad-libitum energy intake in non-obese young males.
Methods: Fourteen healthy males (mean (SD) age 27 (3) y, Height 1.83 (0.05) m, body weight 80.47 (9.89) kg, body fat 17.5 (4.0) %, body mass index 24.0 (2.5) kg/m2) completed a familiarisation trial and two experimental trials in randomised counterbalanced order. Subjects arrived at the laboratory overnight fasted and consumed an ad-libitum porridge breakfast. Immediately prior to the meal, subjects consumed either a 568 ml (1 pint) water preload (preload trial) or no preload (control trial). Visual analogue scale questionnaires to assess hunger, fullness and satisfaction were completed before and after the meal in both trials, as well as after the water preload.
Results: Ad-libitum energy intake was greater (P<0.001) during control (2551 (562) kJ) than preload (1967 (454) kJ). Ad-libitum water intake was also greater (P<0.001) during control (318 (226-975) ml) than preload (116 (0-581) ml). The water preload increased fullness and satisfaction and decreased hunger compared to pre-trial (P<0.001) and the control trial (P<0.001).
Conclusion: This study demonstrates that consumption of a 568 ml water preload immediately before a meal reduces energy intake in non-obese young males. This might therefore be an effective strategy to suppress energy intake in this population and possibly assist with weight management
Fermi Large Area Telescope Observations of the Cosmic-Ray Induced gamma-ray Emission of the Earth's Atmosphere
We report on measurements of the cosmic-ray induced gamma-ray emission of
Earth's atmosphere by the Large Area Telescope onboard the Fermi Gamma-ray
Space Telescope. The LAT has observed the Earth during its commissioning phase
and with a dedicated Earth-limb following observation in September 2008. These
measurements yielded 6.4 x 10^6 photons with energies >100MeV and ~250hours
total livetime for the highest quality data selection. This allows the study of
the spatial and spectral distributions of these photons with unprecedented
detail. The spectrum of the emission - often referred to as Earth albedo
gamma-ray emission - has a power-law shape up to 500 GeV with spectral index
Gamma = 2.79+-0.06.Comment: Accepted for publication in PR
- …