3,082 research outputs found
Climatological characteristics of high altitude wind shear and lapse rate layers
Indications of the climatological distribution of wind shear and temperature lapse and inversion rates as observed by rawinsonde measurements over the western United States are recorded. Frequencies of the strongest shear, lapse rates, and inversion layer strengths were observed for a 1 year period of record and were tabulated for the lower troposphere, the upper troposphere, and five altitude intervals in the lower stratosphere. Selected bivariate frequencies were also tabulated. Strong wind shears, lapse rates, and inversion are observed less frequently as altitude increases from 175 millibars to 20 millibars. On a seasonal basis the frequencies were higher in winter than in summer except for minor influences due to increased tropopause altitude in summer and the stratospheric wind reversal in the spring and fall
Revised prediction (estimation) of Cape Kennedy, Florida, wind speed profile
The prediction of the wind profile maximum speed at Cape Kennedy, Florida, is made for any selected calendar data. The prediction is based on a normal probability distribution model with 15 years of smoothed input data and is static in the sense that no dynamic principles of persistence or synoptic features are considered. Comparison with similar predictions based on 6 years of data shows the same general pattern, but the variability decreased with the increase of sample size
Probabilities of good, marginal, and poor flying conditions for space shuttle ferry flights
Empirical probabilities are provided for good, marginal, and poor flying weather for ferrying the Space Shuttle Orbiter from Edwards AFB, California, to Kennedy Space Center, Florida, and from Edwards AFB to Marshall Space Flight Center, Alabama. Results are given by month for each overall route plus segments of each route. The criteria for defining a day as good, marginal, or poor and the method of computing the relative frequencies and conditional probabilities for monthly reference periods are described
An empirical analysis of the 10-15 km maximum winds to determine Apollo and AAP launch opportunities, Cape Kennedy, Florida
Empirical analysis of maximum wind speeds in space vehicular dynamic pressure region over Cape Kennedy for Apollo and AAP launche
Impulse control disorders in Parkinson's disease: decreased striatal dopamine transporter levels
Objective Impulse control disorders are commonly associated with dopaminergic therapy in Parkinson's disease (PD). PD patients with impulse control disorders demonstrate enhanced dopamine release to conditioned cues and a gambling task on [11C]raclopride positron emission tomography (PET) imaging and enhanced ventral striatal activity to reward on functional MRI. We compared PD patients with impulse control disorders and age-matched and gender-matched controls without impulse control disorders using [123I]FP-CIT (2β-carbomethoxy-3β-(4-iodophenyl)tropane) single photon emission computed tomography (SPECT), to assess striatal dopamine transporter (DAT) density.
Methods The [123I]FP-CIT binding data in the striatum were compared between 15 PD patients with and 15 without impulse control disorders using independent t tests.
Results Those with impulse control disorders showed significantly lower DAT binding in the right striatum with a trend in the left (right: F(1,24)=5.93, p=0.02; left: F(1,24)=3.75, p=0.07) compared to controls.
Conclusions Our findings suggest that greater dopaminergic striatal activity in PD patients with impulse control disorders may be partly related to decreased uptake and clearance of dopamine from the synaptic cleft. Whether these findings are related to state or trait effects is not known. These findings dovetail with reports of lower DAT levels secondary to the effects of methamphetamine and alcohol. Although any regulation of DAT by antiparkinsonian medication appears to be modest, PD patients with impulse control disorders may be differentially sensitive to regulatory mechanisms of DAT expression by dopaminergic medications
Task-specific transfer of perceptual learning across sensory modalities
It is now widely accepted that primary cortical areas of the brain that were once thought to be sensory-specific undergo significant functional reorganisation following sensory deprivation. For instance, loss of vision or audition leads to the brain areas normally associated with these senses being recruited by the remaining sensory modalities [1]. Despite this, little is known about the rules governing crossmodal plasticity in people who experience typical sensory development, or the potential behavioural consequences. Here, we used a novel perceptual learning paradigm to assess whether the benefits associated with training on a task in one sense transfer to another sense. Participants were randomly assigned to a spatial or temporal task that could be performed visually or aurally, which they practiced for five days; before and after training, we measured discrimination thresholds on all four conditions and calculated the extent of transfer between them. Our results show a clear transfer of learning between sensory modalities; however, generalisation was limited to particular conditions. Specifically, learned improvements on the spatial task transferred from the visual domain to the auditory domain, but not vice versa. Conversely, benefits derived from training on the temporal task transferred from the auditory domain to visual domain, but not vice versa. These results suggest a unidirectional transfer of perceptual learning from dominant to non-dominant sensory modalities and place important constraints on models of multisensory processing and plasticity
Sample Preparation for N-Glycosylation Analysis of Therapeutic Monoclonal Antibodies by Electrophoresis
There are a considerable number of biopharmaceuticals that have been approved for clinical use in the past
decade. Over half of these new generation drugs are glycoproteins, such as monoclonal antibodies or other
recombinant glycoproteins, which are mostly produced in mammalian cell lines. The linked carbohydrate
moieties affect not only their physicochemical properties and thermal stability but also crucial features like
receptor-binding activity, circulating half-life, as well as immunogenicity. The structural diversity of these
attached glycans can be manifested in altered monosaccharide composition and linkages/positions among
the monosaccharide building blocks. In addition, as more and more biosimilar products hit the market,
understanding the effects of their glycosylation modifi
cation has become a recent target in effi
cacy and
safety issues. To ensure consistent quality of these products, glycosylation profi
les have to be monitored
and controlled in all steps of the manufacturing process, i.e., from clone selection to lot release. In this
paper, we describe some of the recently introduced and commonly used sample preparation techniques for
capillary electrophoresis (CE)-based profi
ling and structural elucidation of N-glycans. The presented pro-
tocols include protein A affi
nity partitioning of monoclonal antibodies (mAbs), enzymatic release of the
N-linked glycans, labeling of the liberated carbohydrates, reaction mixture purifi
cation techniques to
remove the excess labeling reagent, and high-resolution and rapid capillary electrophoresis-laser-induced
fl
uorescence (CE-LIF)-based profi
ling of the labeled and purifi
ed N-glycans
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