1,765 research outputs found
Analysis of Super-Kamiokande 5-day Measurements of the Solar Neutrino Flux
Data in 5-day bins, recently released by the Super-Kamiodande Consortium, has
been analyzed by a likelihood procedure that has certain advantages over the
Lomb-Scargle procedure used by the consortium. The two most prominent peaks in
the power spectrum of the 10-day data were at 9.42 y-1 and 26.57 y-1, and it
was clear that one was an alias of the other caused by the regularity of the
binning. There were reasons to believe that the 9.42 y-1 peak was an alias of
the 26.57 y-1 peak, but analysis of the 5-day data makes it clear that the
reverse is the case. In addition to a strong peak near 9.42 y-1, we find peaks
at 43.72 y-1and at 39.28 y-1. After comparing this analysis with a
power-spectrum analysis of magnetic-field data, we suggest that these three
peaks may be attributed to a harmonic of the solar rotation rate and to an
r-mode oscillation with spherical harmonic indices l = 2, m = 2.Comment: Accepted for publication in Astrophysical Journa
Further Evidence Suggestive of a Solar Influence on Nuclear Decay Rates
Recent analyses of nuclear decay data show evidence of variations suggestive
of a solar influence. Analyses of datasets acquired at the Brookhaven National
Laboratory (BNL) and at the Physikalisch-Technische Bundesanstalt (PTB) both
show evidence of an annual periodicity and of periodicities with sidereal
frequencies in the neighborhood of 12.25 year^{-1} (at a significance level
that we have estimated to be 10^{-17}). It is notable that this implied
rotation rate is lower than that attributed to the solar radiative zone,
suggestive of a slowly rotating solar core. This leads us to hypothesize that
there may be an "inner tachocline" separating the core from the radiative zone,
analogous to the "outer tachocline" that separates the radiative zone from the
convection zone. The Rieger periodicity (which has a period of about 154 days,
corresponding to a frequency of 2.37 year^{-1}) may be attributed to an r-mode
oscillation with spherical-harmonic indices l=3, m=1, located in the outer
tachocline. This suggests that we may test the hypothesis of a solar influence
on nuclear decay rates by searching BNL and PTB data for evidence of a
"Rieger-like" r-mode oscillation, with l=3, m=1, in the inner tachocline. The
appropriate search band for such an oscillation is estimated to be 2.00-2.28
year^{-1}. We find, in both datasets, strong evidence of a periodicity at 2.11
year^{-1}. We estimate that the probability of obtaining these results by
chance is 10^{-12}.Comment: 12 pages, 6 figures, v2 has a color corrected Fig 6, a corrected
reference, and a corrected typ
Are the General Medical Council's Tests of Competence fair to long standing doctors? A retrospective cohort study.
The General Medical Council's Fitness to Practise investigations may involve a test of competence for doctors with performance concerns. Concern has been raised about the suitability of the test format for doctors who qualified before the introduction of Single Best Answer and Objective Structured Clinical Examination assessments, both of which form the test of competence. This study explored whether the examination formats used in the tests of competence are fair to long standing doctors who have undergone fitness to practise investigation
Comparative Analysis of Super-Kamiokande and SNO Solar-Neutrino Data and the Photospheric Magnetic Field
We analyze Super-Kamiokande, SNO, and photospheric magnetic-field data for
the common time interval, namely the SNO D2O phase. Concerning rotational
modulation, the magnetic-field power spectrum shows the strongest peaks at the
second and sixth harmonics of the solar synodic rotation frequency [3 nu(rot)
and 7 nu(rot)]. The restricted Super-Kamiokande dataset shows strong modulation
at the second harmonic. The SNO D2O dataset shows weak modulation at that
frequency, but strong modulation in the sixth-harmonic frequency band. We
estimate the significance level of the correspondence of the Super-Kamiokande
second-harmonic peak with the corresponding magnetic-field peak to be 0.0004,
and the significance level of the correspondence of the SNO D2O sixth-harmonic
peak with the corresponding magnetic-field peak to be 0.009. By estimating the
amplitude of the modulation of the solar neutrino flux at the second harmonic
from the restricted Super-Kamiokande dataset, we find that the weak power at
that frequency in the SNO D2O power spectrum is not particularly surprising.
Concerning 9.43 yr-1, we find no peak at this frequency in the power spectrum
formed from the restricted Super-Kamiokande dataset, so it is no surprise that
this peak does not show up in the SNO D2O dataset, either.Comment: 32 pages, 8 tables, 16 figure
Reverse Current in Solar Flares
The theory that impulsive X ray bursts are produced by high energy electrons streaming from the corona to the chromosphere is investigated. Currents associated with these streams are so high that either the streams do not exist or their current is neutralized by a reverse current. Analysis of a simple model indicates that the primary electron stream leads to the development of an electric field in the ambient corona which decelerates the primary beam and produces a neutralizing reverse current. It appears that, in some circumstances, this electric field could prevent the primary beam from reaching the chromosphere. In any case, the electric field acts as an energy exchange mechanism, extracting kinetic energy from the primary beam and using it to heat the ambient plasma. This heating is typically so rapid that it must be expected to have important dynamical consequences
Review of Methods of Power-Spectrum Analysis as Applied to Super-Kamiokande Solar Neutrino Data
To help understand why different published analyses of the Super-Kamiokande
solar neutrino data arrive at different conclusions, we have applied six
different methods to a standardized problem. The key difference between the
various methods rests in the amount of information that each processes. A
Lomb-Scargle analysis that uses the mid times of the time bins and ignores
experimental error estimates uses the least information. A likelihood analysis
that uses the start times, end times, and mean live times, and takes account of
the experimental error estimates, makes the greatest use of the available
information. We carry out power-spectrum analyses of the Super-Kamiokande 5-day
solar neutrino data, using each method in turn, for a standard search band (0
to 50 yr-1). For each method, we also carry out a fixed number (10,000) of
Monte-Carlo simulations for the purpose of estimating the significance of the
leading peak in each power spectrum. We find that, with one exception, the
results of these calculations are compatible with those of previously published
analyses. (We are unable to replicate Koshio's recent results.) We find that
the significance of the peaks at 9.43 yr-1 and at 43.72 yr-1 increases
progressively as one incorporates more information into the analysis procedure.Comment: 21 pages, 25 figure
Insanity during the puerperium
I. That any variety o.f mental disease may have
its starting point in the Puerperium.
II. That the common varieties directly due to
puerperal causes have a common symptom viz.
confusion.
III. That this confusion nay be combined with
excitement in the form of
1. Acute Mania with confusion and
2. Conditions of Acute delirium which latter
are severe forms of the confusional excitement,
and that these two constitute by far the most
cases occurring in the first fortnight.
IV. That symptoms of Katatonia may occur in any of
the varieties, and together with confusion
may give rise to conditions of stupor.
V. That confusion with Melancholia is the mental
state in most of those cases that begin late in
the Puerperium.
VI. That the acute confusional excitements may be
due to sepsis or collapse and that the prolonged
cases of delirium usually known as Acute Delirious
Mania are on the mental side no more acute than
some of the rapidly recovering cases,and that
the gravity of the condition is due to physical
conditions.
VII. That many of the prolonged delirious conditions
are streptococcal in origin and that the infection
is probably in many cases a tubal one.
VIII. That the neurotic diathesis is present in nearly
every case and is probably in inverse ratio to
the amount of the sum of the other predisposing ;&nd
exciting causes.
IX.That mild sepsis may bring about Insanity in
combination with a severe neurotic tendency.
X. That apart from extraneous complications viz.
Consumption: death from suicidal wounds etc:
those cases that die in spite of treatment are
almost all septicaemic in origin.
XI. That the causes of the milder confusional states
and melancholic states are probably exhaustion,
mental or physical, and that intestinal and metabolic
toxaemias may play a contributory part in their
causation.
XII. That examination of the blood points to a toxic
element in excited cases apart from sepsis and
that the cases due to collapse and exhaustion
are probably,as the result of diminished power
of immunity in the blood and diminished nervous
resistance, in part the result of autointoxication.
XIII. That the mental symptoms even in melancholic
cases are suggestive of a toxaemia.
XIV. That the prognosis in Puerperal Insanity is good.
That complete mental recovery takes place in the
majority of cases,and even the patient who is
most unstable mentally may recover most quickly
if treatment is begun at once. That the
prognosis is unfavourable in proportion to the
duration of action of the predisposing causes and
to the severity of the physical exciting causes.
XV. That in the treatment of the cases of excitement
and delirium antistreptococcic serum may be of
value. That it must be given immediately and in
sufficient doses in those cases where the
temperature does net fall under othez1 treatmentand
that even after the temperature has been
elevated for some time, very large doses should
be tried, guided by the leucocytcsis
Environmental effects on magnetic fluorescent powder development of fingermarks on bird of prey feathers
A comparison study of the effects of environmental conditions on the development of latent fingermarks on raptor feathers using green magnetic fluorescent powder was undertaken using both sebaceous loaded and natural fingermark deposits. Sparrowhawk feathers were stored in indoor conditions for 60 days (Study 1), and buzzard feathers were left exposed to two different environmental conditions (hidden and visible) for 21 days (Study 2), with developments made at regular ageing periods. In Study 1, latent fingermarks were successfully developed (Grade 1–4) on the indoor feathers up to 60 days after deposition – 98.6% of the loaded deposits and 85.3% for natural deposits. Under outdoor conditions in Study 2, both loaded and natural deposits were affected by environmental exposure. Latent fingermarks were successfully developed up to 14 days after deposition on the outdoor feathers, with some occasional recovery after 21 days. The visible feathers recorded 34.7% (loaded) and 16.4% (natural) successful developments (Grade 1–4), whereas the hidden feathers recorded 46.7% (loaded) and 22.2% (natural) successful developments, suggesting that protection from the environment helps to preserve latent fingermarks on the surface of a feather. Environmental exposure accelerated the deterioration of ridge detail and the number of successful developments
Pulsar extinction
Radio emission from pulsars, attributed to an instability associated with the creation of electron-positron pairs from gamma rays was investigated. The condition for pair creation therefore lead to an extinction condition. The relevant physical processes were analyzed in the context of a mathematical model, according to which radiation originated at the polar caps and magnetic field lines changed from a closed configuration to an open configuration at the force balance or corotation radius
Doctors who pilot the GMC's Tests of Competence: who volunteers and why?
Background: Doctors who are investigated by the General Medical Council (GMC) for performance concerns may be required to take a Test of Competence (ToC). The tests are piloted on volunteer doctors before they are used in Fitness to Practise (FtP) investigations. Objectives: To find out who volunteers to take a pilot ToC and why. Methods: This was a retrospective cohort study. Between February 2011 and October 2012 we asked doctors who volunteered for a test to complete a questionnaire about their reasons for volunteering and recruitment. We analysed the data using descriptive statistics and Pearson’s chi-square test. Results: 301 doctors completed the questionnaire. Doctors who took a ToC voluntarily were mostly women, of white ethnicity, of junior grades, working in general practice and who held a Primary Medical Qualification from the UK. This was a different population to doctors under investigation and all registered doctors in the UK. Most volunteers heard about the GMC’s pilot events through email from a colleague and used the experience to gain exam practice for forthcoming postgraduate exams. Conclusions: The reference group of volunteers are not representative of doctors under FtP investigation. Our findings will be used to inform future recruitment strategies with the aim to encourage better matching of groups who voluntarily pilot a ToC with those under FtP investigation
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