2,256 research outputs found
Social Zapping: Examining Predictors of Last-Minute Cancelations Among Community Members
Social zapping refers to the tendency to cancel plans or appointments shortly before they are supposed to take place in order to attend plans deemed “better” than the original (Müller et al., 2020). With the recent global pandemic occurring and forced isolation presenting as a consequence, the population more than ever has turned to technology to keep up with their relationships (Pennington, 2021). Because of this, social zapping has become increasingly prevalent. Although there is clear need to assess social zapping, few empirical studies have been conducted regarding the predictors and implications of social zapping (Müller et al., 2020; 2021). The present study sought to examine potential predictors of social zapping, including behavioral traits such as the four fundamental needs (belongingness, self-esteem, sense of control, and meaningful existence). Furthermore, the present study sought to determine if the four fundamental needs were predictors of social zapping in individuals aged 40-75 years old. Data utilized for the present study was collected in 2021. The present study found that belongingness and self-esteem significantly predicted social zapping tendencies with belongingness being the strongest predictor. The present study also found that older adults have a significant, more positive relationship with self-esteem, sense of control, and meaningful existence than individuals aged 39 and younger. The population of young adults (aged 18-39) were found to have stronger, more positive relationships with belongingness. Social zapping was found to be nonsignificant for both older adults and younger adults. The current study additionally found social desirability to be a significant predictor of self-esteem and meaningful existence. Overall, the present study builds on what is currently a new phenomenon in research and will provide new information on the relationship between age, social zapping, and behavioral traits such as the four fundamental needs
Thermal Infrared Observations of Asteroid (99942) Apophis with Herschel
The near-Earth asteroid (99942) Apophis is a potentially hazardous asteroid.
We obtained far-infrared observations of this asteroid with the Herschel Space
Observatory's PACS instrument at 70, 100, and 160 micron. These were taken at
two epochs in January and March 2013 during a close Earth encounter. These
first thermal measurements of Apophis were taken at similar phase angles before
and after opposition. We performed a detailed thermophysical model analysis by
using the spin and shape model recently derived from applying a 2-period
Fourier series method to a large sample of well-calibrated photometric
observations. We find that the tumbling asteroid Apophis has an elongated shape
with a mean diameter of 375 m (of an equal volume sphere) and a
geometric V-band albedo of 0.30. We find a thermal inertia in
the range 250-800 JmsK (best solution at 600
JmsK), which can be explained by a mixture of low
conductivity fine regolith with larger rocks and boulders of high thermal
inertia on the surface. The thermal inertia, and other similarities with
(25143) Itokawa indicate that Apophis might also have a rubble-pile structure.
If we combine the new size value with the assumption of an Itokawa-like density
and porosity we estimate a mass between 4.4 and 6.2 10 kg which is more
than 2-3 times larger than previous estimates. We expect that the newly derived
properties will influence impact scenario studies and influence the long-term
orbit predictions of Apophis.Comment: Accepted for publication in Astronomy & Astrophysics, 21 pages, 8
figures, 2 table
Development of glycinergic innervation to the murine LSO and SPN in the presence and absence of the MNTB
Neurons in the superior olivary complex (SOC) integrate excitatory and inhibitory inputs to localize sounds in space. The majority of these inhibitory inputs have been thought to arise within the SOC from the medial nucleus of the trapezoid body (MNTB). However, recent work demonstrates that glycinergic innervation of the SOC persists in Egr2; En1CKO mice that lack MNTB neurons, suggesting that there are other sources of this innervation (Jalabi et al., 2013). To study the development of MNTB- and non-MNTB-derived glycinergic SOC innervation, we compared immunostaining patterns of glycine transporter 2 (GlyT2) at several postnatal ages in control and Egr2; En1CKO mice. GlyT2 immunostaining was present at birth (P0) in controls and reached adult levels by P7 in the superior paraolivary nucleus (SPN) and by P12 in the lateral superior olive (LSO). In Egr2; En1CKO mice, glycinergic innervation of the LSO developed at a similar rate but was delayed by one week in the SPN. Conversely, consistent reductions in the number of GlyT2+ boutons located on LSO somata were seen at all ages in Egr2; En1CKO mice, while these numbers reached control levels in the SPN by adulthood. Dendritic localization of GlyT2+ boutons was unaltered in both the LSO and SPN of adult Egr2; En1CKO mice. On the postsynaptic side, adult Egr2; En1CKO mice had reduced glycine receptor α (GlyRα1) expression in the LSO but normal levels in the SPN. GlyRα2 was not expressed by LSO or SPN neurons in either genotype. These findings contribute important information for understanding the development of MNTB- and non-MNTB-derived glycinergic pathways to the mouse SOC
Physical Properties of OSIRIS-REx Target Asteroid (101955) 1999 RQ36 derived from Herschel, ESO-VISIR and Spitzer observations
In September 2011, the Herschel Space Observatory performed an observation
campaign with the PACS photometer observing the asteroid (101955) 1999 RQ36 in
the far infrared. The Herschel observations were analysed, together with ESO
VLT-VISIR and Spitzer-IRS data, by means of a thermophysical model in order to
derive the physical properties of 1999 RQ36. We find the asteroid has an
effective diameter in the range 480 to 511 m, a slightly elongated shape with a
semi-major axis ratio of a/b=1.04, a geometric albedo of 0.045 +0.015/-0.012,
and a retrograde rotation with a spin vector between -70 and -90 deg ecliptic
latitude. The thermal emission at wavelengths below 12 micron -originating in
the hot sub-solar region- shows that there may be large variations in roughness
on the surface along the equatorial zone of 1999 RQ36, but further measurements
are required for final proof. We determine that the asteroid has a
disk-averaged thermal inertia of Gamma = 650 Jm-2s-0.5K-1 with a 3-sigma
confidence range of 350 to 950 Jm-2s-0.5K-1, equivalent to what is observed for
25143 Itokawa and suggestive that 1999 RQ36 has a similar surface texture and
may also be a rubble-pile in nature. The low albedo indicates that 1999 RQ36
very likely contains primitive volatile-rich material, consistent with its
spectral type, and that it is an ideal target for the OSIRIS-REx sample return
mission.Comment: Accepted for publication in Astronomy & Astrophysics, 9 pages, 7
figure
A New Bi-Functional Derivative of Polyethylene Glycol as Molecular Carrier for Eugenol and Ibuprofen
Eugenol (EU) and ibuprofene (IBU) were covalently bound to a bi-functionalized PEG, used as molecular carrier of drugs and the release kinetics of the two bioactive molecules was studied in vitro in buffer solution at pH 7.4, in simulated gastric fluid and in mouse plasma. The hydrolysis studies showed a specific cleavage dependent on the pH of the medium and by the presence of proteolytic enzymes in mouse plasma. Studies in vitro on the release of the parent drug from this double prodrug in various media, indicate that the adduct may be sufficiently stable to pass intact the gastrointestinal tract and release into the circulation EU and IBU. Many advantages may be achieved by the synthesis of the prodrug EU-PEG-IBU related to synergistic analgesic and anti-inflammatory effects, to the reduction of the adverse reactions and the improvement of the chemical-physical properties of the parent drugs
Mycochemical study of polysaccharides from the edible mushroom Cortinarius caperatus (Gypsy mushroom)
Among basidiomycete molecules, cell wall polysaccharides have been recognized as a major class of bioactive constituents. [1] They are safe molecules and they have a wide spectrum of biological activities, such as immunostimulatory and antioxidant, therefore they possess a prominent role in health benefits coming from mushroom consumption. These properties make mushroom polysaccharides potential candidates for nutraceutical applications and bioactive ingredients production. [2]
Fractionation of the hot aqueous extract of Cortinarius caperatus led to isolation of two fractions characterized by spectroscopic analyses (1H-NMR, 13C-NMR, DEPT, 1H-1H COSY, DQCOSY, TOCSY, HSQC, HMBC and HMQC), mass spectrometry (EI-MS, ESI-MS), infrared spectroscopy (FT-IR), chemical reactions of hydrolysis and derivatization followed by GC and HPLC analyses. [3] This mycochemical study revealed a water-soluble fraction characterized as a \u3b2-(1\uf0e06)-D-glucan, whose presence inside C. caperatus has never, to the best of our knowledge, been reported before. Moreover, a water insoluble fraction purified has been characterized as a branched \uf061, (1\u21926) glucan which structure is assumed to be:
[\u21926)-\u3b2-D-Glcp(1\u21926)]4-\u3b1-D-Glcp(1\u21924)-\u3b2-D-Glcp(1\u2192
6
\u2191
1
\u3b1-D-Glcp
The antioxidant activity of the soluble polysaccharide fraction has been evaluated as radical-scavenging activity with the DPPH test, the \u3b2-(1\uf0e06)-D-glucan showed significative antioxidant activity
Magnetic versus crystal field linear dichroism in NiO thin films
We have detected strong dichroism in the Ni x-ray absorption
spectra of monolayer NiO films. The dichroic signal appears to be very similar
to the magnetic linear dichroism observed for thicker antiferromagnetic NiO
films. A detailed experimental and theoretical analysis reveals, however, that
the dichroism is caused by crystal field effects in the monolayer films, which
is a non trivial effect because the high spin Ni ground state is not
split by low symmetry crystal fields. We present a practical experimental
method for identifying the independent magnetic and crystal field contributions
to the linear dichroic signal in spectra of NiO films with arbitrary
thicknesses and lattice strains. Our findings are also directly relevant for
high spin and systems such as LaFeO, FeO,
VO, LaCrO, CrO, and Mn manganate thin films
A Compact Solid State Detector for Small Angle Particle Tracking
MIDAS (MIcrostrip Detector Array System) is a compact silicon tracking
telescope for charged particles emitted at small angles in intermediate energy
photonuclear reactions. It was realized to increase the angular acceptance of
the DAPHNE detector and used in an experimental program to check the
Gerasimov-Drell-Hearn sum rule at the Mainz electron microtron, MAMI. MIDAS
provides a trigger for charged hadrons, p/pi identification and particle
tracking in the region 7 deg < theta < 16 deg. In this paper we present the
main characteristics of MIDAS and its measured performances.Comment: 13 pages (9 figures). Submitted to NIM
Physical Properties of Asteroid (308635) 2005 YU55 derived from multi-instrument infrared observations during a very close Earth-Approach
The near-Earth asteroid (308635) 2005 YU55 is a potentially hazardous
asteroid which was discovered in 2005 and passed Earth on November 8th 2011 at
0.85 lunar distances. This was the closest known approach by an asteroid of
several hundred metre diameter since 1976 when a similar size object passed at
0.5 lunar distances. We observed 2005 YU55 from ground with a recently
developed mid-IR camera (miniTAO/MAX38) in N- and Q-band and with the
Submillimeter Array (SMA) at 1.3 mm. In addition, we obtained space
observations with Herschel/PACS at 70, 100, and 160 micron. Our thermal
measurements cover a wide range of wavelengths from 8.9 micron to 1.3 mm and
were taken after opposition at phase angles between -97 deg and -18 deg. We
performed a radiometric analysis via a thermophysical model and combined our
derived properties with results from radar, adaptive optics, lightcurve
observations, speckle and auxiliary thermal data. We find that (308635) 2005
YU55 has an almost spherical shape with an effective diameter of 300 to 312 m
and a geometric albedo pV of 0.055 to 0.075. Its spin-axis is oriented towards
celestial directions (lam_ecl, beta_ecl) = (60 deg +/- 30deg, -60 deg +/- 15
deg), which means it has a retrograde sense of rotation. The analysis of all
available data combined revealed a discrepancy with the radar-derived size. Our
radiometric analysis of the thermal data together with the problem to find a
unique rotation period might be connected to a non-principal axis rotation. A
low to intermediate level of surface roughness (r.m.s. of surface slopes in the
range 0.1 - 0.3) is required to explain the available thermal measurements. We
found a thermal inertia in the range 350-800 Jm^-2s^-0.5K^-1, very similar to
the rubble-pile asteroid (25143) Itokawa and indicating a mixture of low
conductivity fine regolith with larger rocks and boulders of high thermal
inertia on the surface.Comment: Accepted for publication in Astronomy & Astrophysics, 12 pages, 10
figure
Intergalactic Photon Spectra from the Far IR to the UV Lyman Limit for and the Optical Depth of the Universe to High Energy Gamma-Rays
We calculate the intergalactic photon density as a function of both energy
and redshift for 0 < z < 6 for photon energies from .003 eV to the Lyman limit
cutoff at 13.6 eV in a Lambda-CDM universe with and
. Our galaxy evolution model gives results which are
consistent with Spitzer deep number counts and the spectral energy distribution
of the extragalactic background radiation. We use our photon density results to
extend previous work on the absorption of high energy gamma-rays in
intergalactic space owing to interactions with low energy photons and the 2.7 K
cosmic background radiation. We calculate the optical depth of the universe,
tau, for gamma-rays having energies from 4 GeV to 100 TeV emitted by sources at
redshifts from ~0 to 5. We also give an analytic fit with numerical
coefficients for approximating . As an example of the
application of our results, we calculate the absorbed spectrum of the blazar
PKS 2155-304 at z = 0.117 and compare it with the spectrum observed by the
H.E.S.S. air Cherenkov gamma-ray telescope array.Comment: final version to be published in Ap
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