3,992 research outputs found
Virtual screening for high affinity guests for synthetic supramolecular receptors
The protein/ligand docking software GOLD, which was originally developed for drug discovery, has been used in a virtual screen to identify small molecules that bind with extremely high affinities (K ≈ 107 M-1) in the cavity of a cubic coordination cage in water. A scoring function was developed using known guests as a training set and modified by introducing an additional term to take account of loss of guest flexibility on binding. This scoring function was then used in GOLD to successfully identify 15 new guests and accurately predict the binding constants. This approach provides a powerful predictive tool for virtual screening of large compound libraries to identify new guests for synthetic hosts, thereby greatly simplifying and accelerating the process of identifying guests by removing the reliance on experimental trial-and-error
The neural correlates of regulating another person's emotions: an exploratory fMRI study
Studies investigating the neurophysiological basis of intrapersonal emotion regulation (control of one's own emotional experience) report that the frontal cortex exerts a modulatory effect on limbic structures such as the amygdala and insula. However, no imaging study to date has examined the neurophysiological processes involved in interpersonal emotion regulation, where the goal is explicitly to regulate another person's emotion. Twenty healthy participants (10 males) underwent fMRI while regulating their own or another person's emotions. Intrapersonal and interpersonal emotion regulation tasks recruited an overlapping network of brain regions including bilateral lateral frontal cortex, pre-supplementary motor area, and left temporo-parietal junction. Activations unique to the interpersonal condition suggest that both affective (emotional simulation) and cognitive (mentalizing) aspects of empathy may be involved in the process of interpersonal emotion regulation. These findings provide an initial insight into the neural correlates of regulating another person's emotions and may be relevant to understanding mental health issues that involve problems with social interaction
Development of a telescope for medium-energy gamma-ray astronomy
The Advanced Energetic Pair Telescope (AdEPT) is being developed at GSFC as a future NASA MIDEX mission to explore the medium-energy (5–200 MeV) gamma-ray range. The enabling technology for AdEPT is the Three- Dimensional Track Imager (3-DTI), a gaseous time projection chamber. The high spatial resolution 3-D electron tracking of 3-DTI enables AdEPT to achieve high angular resolution gamma-ray imaging via pair production and triplet production (pair production on electrons) in the medium-energy range. The low density and high spatial resolution of 3-DTI allows the electron positron track directions to be measured before they are dominated by Coulomb scattering. Further, the significant reduction of Coulomb scattering allows AdEPT to be the first medium-energy gamma-ray telescope to have high gamma-ray polarization sensitivity. We review the science goals that can be addressed with a medium-energy pair telescope, how these goals drive the telescope design, and the realization of this design with AdEPT. The AdEPT telescope for a future MIDEX mission is envisioned as a 8 m3 active volume filled with argon at 2 atm. The design and performance of the 3-DTI detectors for the AdEPT telescope are described as well as the outstanding instrument challenges that need to be met for the AdEPT mission
The neural correlates of emotion regulation by implementation intentions
Several studies have investigated the neural basis of effortful emotion regulation (ER) but the neural basis of automatic ER has been less comprehensively explored. The present study investigated the neural basis of automatic ER supported by ‘implementation intentions’. 40 healthy participants underwent fMRI while viewing emotion-eliciting images and used either a previously-taught effortful ER strategy, in the form of a goal intention (e.g., try to take a detached perspective), or a more automatic ER strategy, in the form of an implementation intention (e.g., “If I see something disgusting, then I will think these are just pixels on the screen!”), to regulate their emotional response. Whereas goal intention ER strategies were associated with activation of brain areas previously reported to be involved in effortful ER (including dorsolateral prefrontal cortex), ER strategies based on an implementation intention strategy were associated with activation of right inferior frontal gyrus and ventro-parietal cortex, which may reflect the attentional control processes automatically captured by the cue for action contained within the implementation intention. Goal intentions were also associated with less effective modulation of left amygdala, supporting the increased efficacy of ER under implementation intention instructions, which showed coupling of orbitofrontal cortex and amygdala. The findings support previous behavioural studies in suggesting that forming an implementation intention enables people to enact goal-directed responses with less effort and more efficiency
Sympathetic Nerve Fibers in Human Cervical and Thoracic Vagus Nerves
Background
Vagus nerve stimulation therapy (VNS) has been used for chronic heart failure (CHF), and is believed to improve imbalance of autonomic control by increasing parasympathetic activity. Although it is known that there is neural communication between the VN and the cervical sympathetic trunk, there are few data regarding the quantity and/or distribution of the sympathetic components within the VN.
Objective
To examine the sympathetic component within human VN and correlate these with the presence of cardiac and neurologic diseases.
Methods
We performed immunohistochemistry on 31 human cervical and thoracic VNs (total 104 VNs) from autopsies and we reviewed the patients’ records. We correlated the quantity of sympathetic nerve fibers within the VNs with cardiovascular and neurologic disease states.
Results
All 104 VNs contain TH positive (sympathetic) nerve fibers; the mean TH positive areas were 5.47% in right cervical, 3.97% in left cervical, 5.11% in right thoracic, and 4.20% in left thoracic VN. The distribution of TH positive nerve fibers varied from case to case: central, peripheral, or scattered throughout nerve bundles. No statistically significant differences in nerve morphology were seen between diseases in which VNS is considered effective (depression and CHF), and other cardiovascular diseases, or neurodegenerative disease.
Conclusion
Human VNs contain sympathetic nerve fibers. The sympathetic component within the VN could play a role in physiologic effects reported with VNS. The recognition of sympathetic nerve fibers in the VNs may lead to better understanding of the therapeutic mechanisms of VNS
Edible crabs “Go West”: migrations and incubation cycle of Cancer pagurus revealed by electronic tags
Crustaceans are key components of marine ecosystems which, like other exploited marine taxa, show seasonable patterns of distribution and activity, with consequences for their availability to capture by targeted fisheries. Despite concerns over the sustainability of crab fisheries worldwide, difficulties in observing crabs’ behaviour over their annual cycles, and the timings and durations of reproduction, remain poorly understood. From the release of 128 mature female edible crabs tagged with electronic data storage tags (DSTs), we demonstrate predominantly westward migration in the English Channel. Eastern Channel crabs migrated further than western Channel crabs, while crabs released outside the Channel showed little or no migration. Individual migrations were punctuated by a 7-month hiatus, when crabs remained stationary, coincident with the main period of crab spawning and egg incubation. Incubation commenced earlier in the west, from late October onwards, and brooding locations, determined using tidal geolocation, occurred throughout the species range. With an overall return rate of 34%, our results demonstrate that previous reluctance to tag crabs with relatively high-cost DSTs for fear of loss following moulting is unfounded, and that DSTs can generate precise information with regards life-history metrics that would be unachievable using other conventional means
Microsystems, Space Qualified Electronics and Mobile Sensor Platforms for Harsh Environment Applications and Planetary Exploration
NASA Glenn Research Center is presently developing and applying a range of sensor and electronic technologies that can enable future planetary missions. These include space qualified instruments and electronics, high temperature sensors for Venus missions, mobile sensor platforms, and Microsystems for detection of a range of chemical species and particulates. A discussion of each technology area and its level of maturity is given. It is concluded that there is a strong need for low power devices which can be mobile and provide substantial characterization of the planetary environment where and when needed. While a given mission will require tailoring of the technology for the application, basic tools which can enable new planetary missions are being developed
A map of OMC-1 in CO 9-8
The distribution of 12C16O J=9-8 (1.037 THz) emission has been mapped in
OMC-1 at 35 points with 84" resolution. This is the first map of this source in
this transition and only the second velocity-resolved ground-based observation
of a line in the terahertz frequency band. There is emission present at all
points in the map, a region roughly 4' by 6' in size, with peak antenna
temperature dropping only near the edges. Away from the Orion KL outflow, the
velocity structure suggests that most of the emission comes from the OMC-1
photon-dominated region, with a typical linewidthof 3-6 km/s. Large velocity
gradient modeling of the emission in J=9-8 and six lower transitions suggests
that the lines originate in regions with temperatures around 120 K and
densities of at least 10^(3.5) cm^(-3) near theta^(1) C Ori and at the Orion
Bar, and from 70 K gas at around 10^(4) cm^(-3) southeast and west of the bar.
These observations are among the first made with the 0.8 m Smithsonian
Astrophysical Observatory Receiver Lab Telescope, a new instrument designed to
observe at frequencies above 1 THz from an extremely high and dry site in
northern Chile.Comment: Minor changes to references, text to match ApJ versio
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