1,385 research outputs found
Use of ERTS-1 data to assess and monitor change in the Southern California environment
There are no author-identified significant results in this report
Large parallel and perpendicular electric fields on electron spatial scales in the terrestrial bow shock
Large parallel ( 100 mV/m) and perpendicular ( 600 mV/m) electric
fields were measured in the Earth's bow shock by the vector electric field
experiment on the Polar satellite. These are the first reported direct
measurements of parallel electric fields in a collisionless shock. These fields
exist on spatial scales comparable to or less than the electron skin depth (a
few kilometers) and correspond to magnetic field-aligned potentials of tens of
volts and perpendicular potentials up to a kilovolt. The perpendicular fields
are amongst the largest ever measured in space, with energy densities of
of order 10%. The measured parallel electric field
implies that the electrons can be demagnetized, which may result in stochastic
(rather than coherent) electron heating
From ‘greenest government ever’ to ‘get rid of all the green crap’: David Cameron, the Conservatives and the environment
The environment was David Cameron’s signature issue underpinning his modernization agenda. In opposition the ‘Vote Blue, Go Green’ strategy had a positive impact on the party’s image: the environment operated as a valence issue in a period of raised public concern, particularly about climate change, and Cameron’s high-profile support contributed to the cross-party consensus that delivered radical change in climate policy. Although the Coalition government has implemented important environmental measures, the Conservatives have not enhanced their green credentials in government and Cameron has failed to provide strong leadership on the issue. Since 2010, climate change has to some extent been transformed into a positional issue. Conservative MPs, urged on by the right-wing press, have adopted an increasingly partisan approach to climate change, and opinion polls reveal clear partisan divisions on climate change amongst public opinion. As a positional issue climate change has become challenging for the Conservatives, showing them to be internally divided, rebellious and inclined to support producer interests. This article makes a contribution to our understanding of Conservative modernization, while also challenging the dominant assumption in the scholarly literature that the environment, particularly climate change, is a valence issue
More and More Restrictive-But Not Always Populist: Explaining Variation in the British Conservative Party's Stance on Immigration and Asylum
This is the Author's Accepted Manuscript of an article published in the Journal of Contemporary European Studies Vol. 21, Iss. 1, copyright Taylor & Francis 2013, available online at: http://www.tandfonline.com/10.1080/14782804.2013.766474Centre-right parties are commonly inclined towards appeals and policies on immigration that are both restrictive in nature and populist in tone-in part because this is what they believe in, in part because it affords them an electoral advantage over their rivals on the centre-left. One would expect, however, that the extent to which they focus on immigration and asylum will vary according to public opinion, according to who leads them, and according to whether they are in government or in opposition. This would appear to be the case for the British Conservative Party, but the relationship is not an entirely consistent one. Moreover, while the Party has, for half a century, pursued ever more restrictive policies, the extent to which it has couched its approach in populist rhetoric varies considerably over time-and not always in line with the severity of its stance on immigration. The reason for this lies partly in the social and economic liberalism of some of its leaders (and in their related concern to act 'responsibly' on race and immigration) but also in their anxiety not to alienate key sections of the middle classes who must be persuaded to support the Party if it is to win elections. These considerations are likely to weigh heavily with other centre-right parties, too. © 2013 Copyright Taylor and Francis Group, LLC
Spacecraft charging and ion wake formation in the near-Sun environment
A three-dimensional (3-D), self-consistent code is employed to solve for the
static potential structure surrounding a spacecraft in a high photoelectron
environment. The numerical solutions show that, under certain conditions, a
spacecraft can take on a negative potential in spite of strong photoelectron
currents. The negative potential is due to an electrostatic barrier near the
surface of the spacecraft that can reflect a large fraction of the
photoelectron flux back to the spacecraft. This electrostatic barrier forms if
(1) the photoelectron density at the surface of the spacecraft greatly exceeds
the ambient plasma density, (2) the spacecraft size is significantly larger
than local Debye length of the photoelectrons, and (3) the thermal electron
energy is much larger than the characteristic energy of the escaping
photoelectrons. All of these conditions are present near the Sun. The numerical
solutions also show that the spacecraft's negative potential can be amplified
by an ion wake. The negative potential of the ion wake prevents secondary
electrons from escaping the part of spacecraft in contact with the wake. These
findings may be important for future spacecraft missions that go nearer to the
Sun, such as Solar Orbiter and Solar Probe Plus.Comment: 25 pages, 7 figures, accepted for publication in Physics of Plasma
The Association of Early Dietary Supplementation with Vitamin E with the Incidence of Ulcerative Dermatitis in Mice on a C57BL/6 Background
The purpose of this study was to ascertain if prophylactic ingestion of a diet rich in vitamin E would prevent or impede the development of ulcerative dermatitis in mice on a C57BL/6 background. Mice were fed after weaning a standard mouse diet, vitamin E (99 IU/kg), or a mouse diet fortified with vitamin E (3000 IU/ kg). Cases of ulcerative dermatitis were recorded by individuals (i.e. aware of) the diet assignment. The incidence of ulcerative dermatitis in a retrospective cohort of mice on standard diet was compared with the group on the diet fortified with vitamin E. Age was associated with ulcerative dermatitis in standard diet and vitamin E fortified diet groups, r = 0.43, p-value < 0.0001 and r = 0.18, p-value < 0.02, respectively. The average age of incidence for ulcerative dermatitis in the mice fed the standard diet was 89 weeks and for the mice fed the vitamin E diet it was 41 weeks. The unadjusted odds ratio comparing the incidence of ulcerative dermatitis between the two diet groups was 4.6 with a 95% confidence interval of (2.44, 8.58), x2 p-value < 0.0001. Therefore, there was an association between the diets and ulcerative dermatitis, with the mice on the vitamin E fortified diet having almost five times the odds of having ulcerative dermatitis compared with mice on the standard diet. Incidence of ulcerative dermatitis was not influenced by sex or genotype. Our study results show that a diet fortified in vitamin E initiated at weaning does not prevent or impede the development of ulcerative dermatitis in mice on a C57BL/6 background and on the contrary accelerate development when administered to young mice.
A Comprehensive View of the 2006 December 13 CME: From the Sun to Interplanetary Space
The biggest halo coronal mass ejection (CME) since the Halloween storm in
2003, which occurred on 2006 December 13, is studied in terms of its solar
source and heliospheric consequences. The CME is accompanied by an X3.4 flare,
EUV dimmings and coronal waves. It generated significant space weather effects
such as an interplanetary shock, radio bursts, major solar energetic particle
(SEP) events, and a magnetic cloud (MC) detected by a fleet of spacecraft
including STEREO, ACE, Wind and Ulysses. Reconstruction of the MC with the
Grad-Shafranov (GS) method yields an axis orientation oblique to the flare
ribbons. Observations of the SEP intensities and anisotropies show that the
particles can be trapped, deflected and reaccelerated by the large-scale
transient structures. The CME-driven shock is observed at both the Earth and
Ulysses when they are separated by 74 in latitude and 117
in longitude, the largest shock extent ever detected. The ejecta seems missed
at Ulysses. The shock arrival time at Ulysses is well predicted by an MHD model
which can propagate the 1 AU data outward. The CME/shock is tracked remarkably
well from the Sun all the way to Ulysses by coronagraph images, type II
frequency drift, in situ measurements and the MHD model. These results reveal a
technique which combines MHD propagation of the solar wind and type II
emissions to predict the shock arrival time at the Earth, a significant advance
for space weather forecasting especially when in situ data are available from
the Solar Orbiter and Sentinels.Comment: 26 pages, 10 figures. 2008, ApJ, in pres
Purification and Characterization of a Mitogenic Lectin from Cephalosporium, a Pathogenic Fungus Causing Mycotic Keratitis
Ophthalmic mycoses caused by infectious fungi are being recognized as a serious concern since they lead to total blindness. Cephalosporium is one amongst several opportunistic fungal species implicated in ophthalmic infections leading to mycotic keratitis. A mitogenic lectin has been purified from the mycelia of fungus Cephalosporium, isolated from the corneal smears of a keratitis patient. Cephalosporium lectin (CSL) is a tetramer with subunit mass of 14 kDa, agglutinates human A, B, and O erythrocytes, and exhibits high affinity for mucin compared to fetuin and asialofetuin but does not bind to simple sugars indicating its complex sugar specificity. CSL showed strong binding to normal
human peripheral blood mononuclear cells (PBMCs) to elicit mitogenic activity. The sugar specificity of the lectin and its interaction with PBMCs to exhibit mitogenic effect indicate its possible role in adhesion and infection process of Cephalosporium
Observations of Energetic-particle Population Enhancements along Intermittent Structures near the Sun from the Parker Solar Probe
Observations at 1 au have confirmed that enhancements in measured energetic-particle (EP) fluxes are statistically associated with "rough" magnetic fields, i.e., fields with atypically large spatial derivatives or increments, as measured by the Partial Variance of Increments (PVI) method. One way to interpret this observation is as an association of the EPs with trapping or channeling within magnetic flux tubes, possibly near their boundaries. However, it remains unclear whether this association is a transport or local effect; i.e., the particles might have been energized at a distant location, perhaps by shocks or reconnection, or they might experience local energization or re-acceleration. The Parker Solar Probe (PSP), even in its first two orbits, offers a unique opportunity to study this statistical correlation closer to the corona. As a first step, we analyze the separate correlation properties of the EPs measured by the Integrated Science Investigation of the Sun (IS⊙IS) instruments during the first solar encounter. The distribution of time intervals between a specific type of event, i.e., the waiting time, can indicate the nature of the underlying process. We find that the IS⊙IS observations show a power-law distribution of waiting times, indicating a correlated (non-Poisson) distribution. Analysis of low-energy (~15 – 200 keV/nuc) IS⊙IS data suggests that the results are consistent with the 1 au studies, although we find hints of some unexpected behavior. A more complete understanding of these statistical distributions will provide valuable insights into the origin and propagation of solar EPs, a picture that should become clear with future PSP orbits
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