517 research outputs found
UVB radiation induced effects on cells studied by FTIR spectroscopy
We have made a preliminary analysis of the results about the eVects on
tumoral cell line (lymphoid T cell line Jurkat) induced by UVB radiation (dose
of 310 mJ/cm^2) with and without a vegetable mixture. In the present study, we
have used two techniques: Fourier transform infrared spectroscopy (FTIR) and
flow cytometry. FTIR spectroscopy has the potential to provide the
identiWcation of the vibrational modes of some of the major compounds (lipid,
proteins and nucleic acids) without being invasive in the biomaterials. The
second technique has allowed us to perform measurements of cytotoxicity and to
assess the percentage of apoptosis. We already studied the induction of
apoptotic process in the same cell line by UVB radiation; in particular, we
looked for correspondences and correlations between FTIR spetroscopy and flow
cytometry data finding three highly probable spectroscopic markers of apoptosis
(Pozzi et al. in Radiat Res 168:698-705, 2007). In the present work, the
results have shown significant changes in the absorbance and spectral pattern
in the wavenumber protein and nucleic acids regions after the treatments
The River Gave and the River Hath Taken Away: How the Arkansas River Shaped the Course of Arkansas History
The Arkansas River molded the history of Arkansas. It also shaped human to human interactions and human relationships with the physical environment. Since humans first encountered the river their lives have been influenced by it. The river played a significant role in creating the environmental conditions that contributed to a specific existence within the river valley. It affected what types of flora and fauna existed, the quality of the soil, and the climate. The river was a vital component in the evolution of the cultures and societies that developed in the river valley. Conversely, humans affected the river. The ways humans perceived and used the river impacted the physical characteristics that defined the river. Ever since the first humans interacted with the river there has been a dialectic relationship put into motion, a cycle of constant change where humans and the environment renegotiated their understandings and relationship with one another. Throughout every time period of Arkansas history, prehistoric through the 1970s and on, the river has been a vital factor in the existence of the river valley and state
Обоснование мер обеспечения эффективности деятельности предприятия пищевой промышленности
У даній статті розглядається поняття та сутність виробничо-господарської діяльності підприємства та наведено основні заходи підвищення її ефективності для підприємств харчової промисловості.This article discusses the concept and nature of industrial and business enterprises and are the main measures to increase its efficiency for the food industry.В данной статье рассматривается понятие и сущность производственной деятельности предприятия и приведены основные меры повышения ее эффективности для предприятий пищевой промышленности
Ears of the Armadillo: Global Health Research and Neglected Diseases in Texas
Neglected tropical diseases (NTDs) have\ud
been recently identified as significant public\ud
health problems in Texas and elsewhere in\ud
the American South. A one-day forum on the\ud
landscape of research and development and\ud
the hidden burden of NTDs in Texas\ud
explored the next steps to coordinate advocacy,\ud
public health, and research into a\ud
cogent health policy framework for the\ud
American NTDs. It also highlighted how\ud
U.S.-funded global health research can serve\ud
to combat these health disparities in the\ud
United States, in addition to benefiting\ud
communities abroad
The Q^2-Dependence of Nuclear Transparency for Exclusive Production
Exclusive coherent and incoherent electroproduction of the meson
from H and N targets has been studied at the HERMES experiment as a
function of coherence length (), corresponding to the lifetime of hadronic
fluctuations of the virtual photon, and squared four-momentum of the virtual
photon (). The ratio of N to H cross sections per nucleon,
known as nuclear transparency, was found to increase (decrease) with increasing
coherence length for coherent (incoherent) electroproduction. For
fixed coherence length, a rise of nuclear transparency with is observed
for both coherent and incoherent production, which is in agreement
with theoretical calculations of color transparency.Comment: 5 pages, 4 figure
Nuclear Polarization of Molecular Hydrogen Recombined on a Non-metallic Surface
The nuclear polarization of molecules formed by recombination
of nuclear polarized H atoms on the surface of a storage cell initially coated
with a silicon-based polymer has been measured by using the longitudinal
double-spin asymmetry in deep-inelastic positron-proton scattering. The
molecules are found to have a substantial nuclear polarization, which is
evidence that initially polarized atoms retain their nuclear polarization when
absorbed on this type of surfac
Double hadron leptoproduction in the nuclear medium
First measurement of double-hadron production in deep-inelastic scattering
has been measured with the HERMES spectrometer at HERA using a 27.6 GeV
positron beam with deuterium, nitrogen, krypton and xenon targets. The
influence of the nuclear medium on the ratio of double-hadron to single-hadron
yields has been investigated. Nuclear effects are clearly observed but with
substantially smaller magnitude and reduced -dependence compared to
previously measured single-hadron multiplicity ratios. The data are in fair
agreement with models based on partonic or pre-hadronic energy loss, while they
seem to rule out a pure absorptive treatment of the final state interactions.
Thus, the double-hadron ratio provides an additional tool for studying
modifications of hadronization in nuclear matter
Single-spin asymmetries in semi-inclusive deep-inelastic scattering on a transversely polarized hydrogen target
Single-spin asymmetries for semi-inclusive electroproduction of charged pions
in deep-inelastic scattering of positrons are measured for the first time with
transverse target polarization. The asymmetry depends on the azimuthal angles
of both the pion () and the target spin axis () about the virtual
photon direction and relative to the lepton scattering plane. The extracted
Fourier component \cmpi is a signal of the previously unmeasured quark
transversity distribution, in conjunction with the so-called Collins
fragmentation function, also unknown. The Fourier component \smpi of the
asymmetry arises from a correlation between the transverse polarization of the
target nucleon and the intrinsic transverse momentum of quarks, as represented
by the previously unmeasured Sivers distribution function. Evidence for both
signals is observed, but the Sivers asymmetry may be affected by exclusive
vector meson productio
Subleading-twist effects in single-spin asymmetries in semi-inclusive deep-inelastic scattering on a longitudinally polarized hydrogen target
Single-spin asymmetries in the semi-inclusive production of charged pions in
deep-inelastic scattering from transversely and longitudinally polarized proton
targets are combined to evaluate the subleading-twist contribution to the
longitudinal case. This contribution is significantly positive for (\pi^+)
mesons and dominates the asymmetries on a longitudinally polarized target
previously measured by \hermes. The subleading-twist contribution for (\pi^-)
mesons is found to be small
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