4,382 research outputs found
Estimating the number of injecting drug users in scotland's HCV-diagnosed population using capture-recapture methods
Depletion of atmospheric nitrate and chloride as a consequence of the Toba Volcanic Eruption
Continuous measurements of SO42− and electrical conductivity (ECM) along the GISP2 ice core record the Toba mega‐eruption at a depth 2590.95 to 2091.25 m (71,000±5000 years ago). Major chemical species were analyzed at a resolution of 1 cm per sample for this section. An ∼6‐year long period with extremely high volcanic SO42− coincident with a 94% depletion of nitrate and 63% depletion of chloride is observed at the depth of the Toba horizon. Such a reduction of chloride in a volcanic layer preserved in an ice core has not been observed in any previous studies. The nearly complete depletion of nitrate (to 5 ppb) encountered at the Toba level is the lowest value in the entire ∼250,000 years of the GISP2 ice core record. We propose possible mechanisms to explain the depletion of nitrate and chloride resulting from this mega‐eruption
Educational weight loss interventions in obese and overweight adults with type 2 diabetes : a systematic review and meta‐analysis of randomized controlled trials
Aim
The worldwide prevalence of type 2 diabetes mellitus is increasing, with most individuals with the disease being overweight or obese. Weight loss can reduce disease‐related morbidity and mortality and weight losses of 10–15 kg have been shown to reverse type 2 diabetes. This review aimed to determine the effectiveness of community‐based educational interventions for weight loss in type 2 diabetes.
Methods
This is a systematic review and meta‐analysis of randomized controlled trials (RCT) in obese or overweight adults, aged 18–75 years, with a diagnosis of type 2 diabetes. Primary outcomes were weight and/or BMI. CINAHL, MEDLINE, Embase, Scopus and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched from inception to June 2019. Trials were classified into specified a priori comparisons according to intervention type. A pooled standardized mean difference (SMD) (from baseline to follow‐up) and 95% confidence intervals (95% CI) between trial groups (difference‐in‐difference) were estimated through random‐effects meta‐analyses using the inverse variance method. Heterogeneity was quantified using I2 and publication bias was explored visually using funnel plots.
Results
Some 7383 records were screened; 228 full‐text articles were assessed and 49 RCTs (n = 12 461 participants) were included in this review, with 44 being suitable for inclusion into the meta‐analysis. Pooled estimates of education combined with low‐calorie, low‐carbohydrate meal replacements (SMD = –2.48, 95% CI –3.59, –1.49, I2 = 98%) or diets (SMD = –1.25, 95% CI –2.11, –0.39, I2 = 95%) or low‐fat meal replacements (SMD = –1.15, 95%CI –2.05, –1.09, I2 = 85%) appeared most effective.
Conclusion
Low‐calorie, low‐carbohydrate meal replacements or diets combined with education appear the most promising interventions to achieve the largest weight and BMI reductions in people with type 2 diabetes
Reinforced structural plastics
Reinforced polyimide structures are described. Reinforcing materials are impregnated with a suspension of polyimide prepolymer and bonded together by heat and pressure to form a cured, hard-reinforced, polyimide structure
Potential atmospheric impact of the Toba Mega‐Eruption ∼71,000 years ago
An ∼6‐year long period of volcanic sulfate recorded in the GISP2 ice core about 71,100 ± 5000 years ago may provide detailed information on the atmospheric and climatic impact of the Toba mega‐eruption. Deposition of these aerosols occur at the beginning of an ∼1000‐year long stadial event, but not immediately before the longer glacial period beginning ∼67,500 years ago. Total stratospheric loading estimates over this ∼6‐year period range from 2200 to 4400 Mt of H2SO4 aerosols. The range in values is given to compensate for uncertainties in aerosol transport. Magnitude and longevity of the atmospheric loading may have led directly to enhanced cooling during the initial two centuries of this ∼1000‐year cooling event
Volcanic aerosol records and tephrochronology of the Summit, Greenland, ice cores
The recently collected Greenland Ice Sheet Project 2 (GISP2) and Greenland Ice Core Project ice cores from Summit, Greenland, provide lengthy and highly resolved records of the deposition of both the aerosol (H2SO4) and silicate (tephra) components of past volcanism. Both types of data are very beneficial in developing the hemispheric to global chronology of explosive volcanism and evaluating the entire volcanism‐climate system. The continuous time series of volcanic SO42− for the last 110,000 years show a strong relationship between periods of increased volcanism and periods of climatic change. The greatest number of volcanic SO42− signals, many of very high magnitude, occur during and after the final stages of deglaciation (6000–17,000 years ago), possibly reflecting the increased crustal stresses that occur with changing volumes of continental ice sheets and with the subsequent changes in the volume of water in ocean basins (sea level change). The increase in the number of volcanic SO42− signals at 27,000–36,000 and 79,000–85,000 years ago may be related to initial ice sheet growth prior to the glacial maximum and prior to the beginning of the last period of glaciation, respectively. A comparison of the electrical conductivity of the GISP2 core with that of the volcanic SO42− record for the Holocene indicates that only about half of the larger volcanic signals are coincident in the two records. Other volcanic acids besides H2SO4 and other SO42− sources can complicate the comparisons, although the threshold level picked to make such comparisons is especially critical. Tephra has been found in both cores with a composition similar to that originating from the Vatnaöldur eruption that produced the Settlement Layer in Iceland (mid‐A.D. 870s), from the Icelandic eruption that produced the Saksunarvatn ash (∼10,300 years ago), and from the Icelandic eruption(s) that produced the Z2 ash zone in North Atlantic marine cores (∼52,700 years ago). The presence of these layers provides absolute time lines for correlation between the two cores and for correlation with proxy records from marine sediment cores and terrestrial deposits containing these same tephras. The presence of both rhyolitic and basaltic shards in the Z2 ash in theGISP2 core and the composition of the basaltic grains lend support to multiple Icelandic sources (Torfajökull area and Katla) for the Z2 layer. Deposition of the Z2 layer occurs at the beginning of a stadial event, further reflecting the possibility of a volcanic triggering by the effects of changing climatic conditions
New rapid-curing, stable polyimide polymers with high-temperature strength and thermal stability
Additive-type polymerization reaction forms thermally stable polyimide polymers, thereby eliminating the volatile matter attendant with the condensation reaction. It is based on the utilization of reactive alicyclic rings positioned on the ends of polyimide prepolymers having relatively low molecular weights
Detection of Gravitational Lensing in the Cosmic Microwave Background
Gravitational lensing of the cosmic microwave background (CMB), a
long-standing prediction of the standard cosmolgical model, is ultimately
expected to be an important source of cosmological information, but first
detection has not been achieved to date. We report a 3.4 sigma detection, by
applying quadratic estimator techniques to all sky maps from the Wilkinson
Microwave Anisotropy Probe (WMAP) satellite, and correlating the result with
radio galaxy counts from the NRAO VLA Sky Survey (NVSS). We present our
methodology including a detailed discussion of potential contaminants. Our
error estimates include systematic uncertainties from density gradients in
NVSS, beam effects in WMAP, Galactic microwave foregrounds, resolved and
unresolved CMB point sources, and the thermal Sunyaev-Zeldovich effect.Comment: 27 pages, 20 figure
Cytochemical and histochemical characterization of cotyledonary bodies from Pharbitis nil seedlings
Cytological
and
histochemical
characterization
of
the
structures
from
which
an
obscure
substance
is
secreted
via
open
stomata
to
the
abaxial
surface
of
Japanese
morning
glory
(Pharbitis
nil
Choisy
cv.
Violet)
cotyledons
has
been
carried
out.
Observation
of
intact
cotyledons
using
the
light
microscope
revealed
randomly
distributed
semi-transparent
structures.
These
structures,
which
were
shown
to
be
the
same
as
those
previously
described
as
giant
oil
cells
are
referred
to
here
as
cotyledonary
bodies.
These
bodies
can
be
eas-
ily
isolated
and
purified
after
enzymatic
digestion
of
the
cotyledons.
Using
different
staining
procedures
we
have
confirmed
that
each
cotyledonary
body
originates
from
an
individual
mesophyll
cell
dur-
ing
embryo
development.
Purified
bodies
consist
of
(i)
a
thick
shell-
like
envelope;
(ii)
a
transparent,
hydrophilic
zone;
(iii)
a
hydropho-
bic
core.
Hydrophobic
contents
of
the
bodies
were
readily
extracted
with
methanol
and
shown
to
contain
fatty
acids
and
phenolic
com-
pounds
using
the
gas
chromatography/mass
spectrometry
(GC/MS)
technique.
Methanolic
extracts
of
cotyledonary
bodies
showed
high
fluorescence
with
two
excitation
and
emission
maxima.
Using
a
flu-
orescence
microscope
we
have
shown
that
the
bodies
isolated
from
seedlings
grown
in
continuous
light,
conditions
non-inductive
for
flowering,
and
those
grown
under
conditions
inductive
for
flowering
(a
single
16
h,
long
dark
period)
have
different
fluorescence
emis-
sion
spectra.
Different
levels
of
free
Ca
2+
inside
cotyledonary
bodies
isolated
from
light-grown
and
single
dark-period
treated
P.
nil
seed-
lings
were
found
using
the
fluorescent
calcium
indicator
dye
Fluo-3
under
a
confocal
scanning
laser
microscope.
On
the
basis
of
these
observations
we
speculate
that
cotyledonary
bodies
could
be
in-
volved
in
floral
induction
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