6,499 research outputs found
Circular 20
Since fanning in Alaska first began and especially
since dairy farming became the primary agricultural
industry, there has existed a need for
hardy legumes which would survive Alaska winters
and produce satisfactory yields of high quality
forage. To meet this need hundreds of legume
species and strains have been introduced during
the past 40 or more years. Almost all have lacked
the necessary hardiness or have not been satisfactory
agronomically. The release of Alaskland
red clover in the spring of 1953 is the first time
a hardy legume has been made available to
growers in Alaska.Cooperating with the United States Department of Agriculture, Agricultural Research Administratio
Effect of Photobiomodulation on Vinblastine-Poisoned Murine HERS Cells
Objective: The aim of this study was to investigate the effect of near-infrared (NIR) photobiomodulation on the proliferation and glutathione levels in murine Hertwig\u27s epithelial root sheath (HERS) cells after poisoning with vinblastine. Background: Photobiomodulation has been shown to improve wound healing in a number of animal models. There have been no studies on the effect of photobiomodulation on cancer-related chemotherapy injury to the cells that initiate tooth root growth. Materials and Methods: Control groups consisted of murine HERS cells without vinblastine (VB−) and cells with vinblastine at 10, 20, and 30 ng/mL (VB10, VB20, and VB30). Experimental groups consisted of these same groups with light therapy (VB-L, VB10L, VB20L, and VB30L). The cells were exposed to vinblastine for 1 h. Photobiomodulation consisted of a 75-cm2 gallium-aluminum-arsenide light-emitting diode (LED) array at an energy density of 12.8 J/cm2, delivered with 50 mW/cm2 power over 256 s. Results: Vinblastine alone significantly decreased HERS cell proliferation and glutathione levels at all concentrations (VB10 [−55%, p \u3c 1.0 × 10−8]; VB20 [−72%, p \u3c 1.0 × 10−9]; VB30 [−80%, p \u3c 1.0 × 10−10]; and VB10 [−36%, p \u3c 0.0001]; VB20 [−49%, p \u3c 1.0 × 10−6]; VB30 [−53%, p \u3c 1.0 × 10−7] respectively). Photobiomodulation significantly increased cell proliferation at all levels of vinblastine exposure (VB10L [+50%, p \u3c 0.0001]; VB20L [+45%, p \u3c 0.05]; VB30 [+39%, p \u3c 0.05]) but not of the control (+22%, p = 0.063). The photobiomodulation significantly increased glutathione production in all concentrations of vinblastine except 20 ng/mL (VB10L [+39%, p = 0.007]; VB20L [+19%, p = 0.087]; VB30 [+14%, p = 0.025]) and the control (+12%, p = 0.13). Conclusions: Photobiomodulation demonstrated an improvement in proliferation and glutathione levels in vinblastine-poisoned murine HERS cells
Intranasal Inhalation of Oxytocin Improves Face Processing in Developmental Prosopagnosia
Developmental prosopagnosia (DP) is characterised by a severe, lifelong impairment in face recognition. Little work has attempted to improve face processing in these individuals, but intriguingly, recent evidence suggests oxytocin can improve face processing in both healthy participants and individuals with autism. This study examined whether oxytocin could also improve face processing in individuals with DP. Ten adults with the condition and 10 matched controls were tested using a randomized placebo-controlled double-blind within-subject experimental design (AB-BA). Each participant took part in two testing sessions where they inhaled 24IU of oxytocin or placebo spray and completed two face processing tests: one assessing face memory and the other face perception. Results showed main effects of both participant group and treatment condition in both face processing tests, but the two did not interact. Specifically, the performance of DP participants was significantly lower than control performance under both oxytocin and placebo conditions, but oxytocin improved processing to a similar extent in both groups
Nuclear symmetry energy and its density slope at normal density extracted from global nucleon optical potentials
Based on the Hugenholtz-Van Hove theorem, it is shown that both the symmetry
energy E and its density slope at normal density
are completely determined by the global nucleon optical potentials
that can be extracted directly from nucleon-nucleus scatterings, (p,n) charge
exchange reactions and single-particle energy levels of bound states. Adopting
a value of for the nucleon effective k-mass in symmetric nuclear
matter at and averaging all phenomenological isovector nucleon
potentials constrained by world data available in the literature since 1969,
the best estimates of MeV and MeV are
simultaneously obtained. Uncertainties involved in the estimates are discussed.Comment: 4 pages including 2 figure
External and internal noise surveys of London primary schools
Internal and external noise surveys have been carried out around schools in London, UK, to provide information on typical levels and sources to which children are exposed while at school. Noise levels were measured outside 142 schools, in areas away from flightpaths into major airports. 86% of the schools surveyed were exposed to noise from road traffic, the average external noise level outside a school being 57 dB LAeq. Detailed internal noise surveys have been carried out in 140 classrooms in 16 schools, together with classroom observations. It was found that noise levels inside classrooms depend upon the activities in which the children are engaged, with a difference of 20 dB LAeq between the 'quietest' and 'noisiest' activities. The average background noise level in classrooms exceeds the level recommended in current standards. The number of children in the classroom was found to affect noise levels. External noise influenced internal noise levels only when children were engaged in the quietest classroom activities. The effects of the age of the school buildings and types of window upon internal noise were examined but results were inconclusive
Learning From Early Attempts to Generalize Darwinian Principles to Social Evolution
Copyright University of Hertfordshire & author.Evolutionary psychology places the human psyche in the context of evolution, and addresses the Darwinian processes involved, particularly at the level of genetic evolution. A logically separate and potentially complementary argument is to consider the application of Darwinian principles not only to genes but also to social entities and processes. This idea of extending Darwinian principles was suggested by Darwin himself. Attempts to do this appeared as early as the 1870s and proliferated until the early twentieth century. But such ideas remained dormant in the social sciences from the 1920s until after the Second World War. Some lessons can be learned from this earlier period, particularly concerning the problem of specifying the social units of selection or replication
Connection between inner jet kinematics and broadband flux variability in the BL Lac object S5 0716+714
We present a high-frequency very long baseline interferometry (VLBI)
kinematical study of the BL Lac object S5 0716+714 over the time period of
September 2008 to October 2010. The aim of the study is to investigate the
relation of the jet kinematics to the observed broadband flux variability. We
find significant non-radial motions in the jet outflow of the source. In the
radial direction, the highest measured apparent speed is \sim37 c, which is
exceptionally high, especially for a BL Lac object. Patterns in the jet flow
reveal a roughly stationary feature \sim0.15 mas downstream of the core. The
long-term fits to the component trajectories reveal acceleration in the sub-mas
region of the jet. The measured brightness temperature, T_{B}, follows a
continuous trend of decline with distance, T_B \propto
r_{jet}^{-(2.36\pm0.41)}, which suggests a gradient in Doppler factor along the
jet axis. Our analysis suggest that a moving disturbance (or a shock wave) from
the base of the jet produces the high-energy (optical to \gamma-ray) variations
upstream of the 7 mm core, and then later causes an outburst in the core.
Repetitive optical/\gamma-ray flares and the curved trajectories of the
associated components suggest that the shock front propagates along a bent
trajectory or helical path. Sharper \gamma-ray flares could be related to the
passage of moving disturbances through the stationary feature. Our analysis
suggests that the \gamma-ray and radio emission regions have different Doppler
factors.Comment: 12 pages, 8 figures, accepted for publication in A&
Nucleon-nucleon cross sections in neutron-rich matter and isospin transport in heavy-ion reactions at intermediate energies
Nucleon-nucleon (NN) cross sections are evaluated in neutron-rich matter
using a scaling model according to nucleon effective masses. It is found that
the in-medium NN cross sections are not only reduced but also have a different
isospin dependence compared with the free-space ones. Because of the
neutron-proton effective mass splitting the difference between nn and pp
scattering cross sections increases with the increasing isospin asymmetry of
the medium. Within the transport model IBUU04, the in-medium NN cross sections
are found to influence significantly the isospin transport in heavy-ion
reactions. With the in-medium NN cross sections, a symmetry energy of
was found most acceptable
compared with both the MSU isospin diffusion data and the presently acceptable
neutron-skin thickness in Pb. The isospin dependent part of isobaric nuclear incompressibility was further narrowed down to
MeV. The possibility of determining simultaneously the in-medium
NN cross sections and the symmetry energy was also studied. The proton
transverse flow, or even better the combined transverse flow of neutrons and
protons, can be used as a probe of the in-medium NN cross sections without much
hindrance from the uncertainties of the symmetry energy.Comment: 32 pages including 14 figures. Submitted to Phys. Rev.
Isospin splitting of the nucleon mean field
The isospin splitting of the nucleon mean field is derived from the Brueckner
theory extended to asymmetric nuclear matter. The Argonne V18 has been adopted
as bare interaction in combination with a microscopic three body force. The
isospin splitting of the effective mass is determined from the
Brueckner-Hartree-Fock self-energy: It is linear acording to the Lane ansatz
and such that for neutron-rich matter. The symmetry potential
is also determined and a comparison is made with the predictions of the
Dirac-Brueckner approach and the phenomenological interactions. The theoretical
predictions are also compared with the empirical parametrizations of neutron
and proton optical-model potentials based on the experimental nucleon-nucleus
scattering and the phenomenological ones adopted in transport-model simulations
of heavy-ion collisions. The direct contribution of the rearrangement term due
to three-body forces to the single particle potential and symmetry potential is
discussed.Comment: 8 pages, 10 figure
A study of the strengthening mechanism in the thermomechanically processed TRIP/TWIP steel
The strengthening mechanism responsible for the unique combination of ultimate tensile strength and elongation in a multiphase Fe-0.2C-1.5Mn-1.2Si-0.3Mo-0.6Al-0.02Nb (wt%) steel was studied. The microstructures with different volume fraction of polygonal fenite, bainite and retained austenite were simulated by controlled thermomechanical processing. The interupted tensile test was used to study the bainitic ferrite, retained austenite and polygonal ferrite behavior as a function of plastic strain. X-ray analysis was used to characterize the volume fraction and carbon content of retained austenite. TEM and heat-tinting were utilized to analyze the effect of bainitic fenite morphology on the strain induced transformation of retained austenite and retained austenite twinning as a function of strain in the bulk material. The study has shown that the austenite twinning mechanism is more preferable than the transformation induced plasticity mechanism during the early stages of deformation for a microstructure containing I5% polygonal ferrite, while the transformation induced plasticity effect is the main mechanism in when there is 50% of polygonal ferrite in the microstructure. The baillitic fenite morphology affects the deformation mode of retained austenite during straining. The polygonal fenite behavior during straining depends on dislocation substructure tonned due to the deformation and the additional mobile dislocations caused by the TRIP effect. TRIP and TWIP effects depend not only on the chemical and mechanical stability of retained austenite, but also on the interaction of the phases during straining.<br /
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