9,314 research outputs found
Flexible blade antenna Patent
Flexible monopole antenna with broad bandwidth and low voltage standing wave rati
The NASA teleconferencing system: An evaluation
The communication requirements of the Apollo project led to the development of a teleconferencing network which linked together, in an audio-fax mode, the several NASA centers and supporting contractors of the Apollo project. The usefulness of this communication linkage for the Apollo project suggested that the system might be extended to include all NASA centers, enabling them to conduct their in-house business more efficiently than by traveling to other centers. A pilot project was run in which seventeen NASA center and subcenters, some with multiple facilities, were connected into the NASA teleconferencing network. During that year, costs were charted and, at the end of the year, an evaluation was made to determine how the system had been used and with what results. The year-end evaluation of the use of NASA teleconferencing system is summarized
Do N3 Fatty Acid Supplements Effect Depressive Symptoms Post Cardiovascular Event in Men and Women Ages 40 and Older?
OBJECTIVE: The objective of this selective EBM review is to determine whether or not n-3 fatty acids have an effect on depressive symptoms post cardiovascular event in men and women ages 40 and older.
STUDY DESIGN: Systematic review of three English language random controlled trials published between 2011-2012.
DATA SOURCES: Two randomized controlled trials published after 2011 comparing the effects of n-3 fatty acid supplementation on depressive symptoms post cardiovascular event and one randomized controlled trial comparing n-3 fatty acid supplementation effects on depressive symptoms in elderly patients with diagnosed depression. The studies were obtained using the PubMed database.
OUTCOMES MEASURED: Depressive symptoms, assessed using the Geriatric Depression Scale, was the primary outcome measured in all three studies. In all studies patients depressive symptoms were measured with the GDS-15 before the trial of supplementation vs. placebo began, and then after the trial was over. Results were then compared before and after supplementation.
RESULTS: The results of these studies show an insignificant decrease in depressive symptoms of patients supplemented with n-3 fatty acids post cardiovascular event vs. a placebo. However, one study showed the potential for n-3 fatty acid supplementation in depressed elderly patients unrelated to cardiovascular events with a decrease in depressive symptoms after supplementation.6 One subgroup in the study by Andreeva and colleagues reported an increase in depressive symptoms in men who were supplemented n-3 fatty acids for the trial.4
CONCLUSIONS: Based on these studies, the use of n-3 fatty acids for decreasing depressive symptoms in post-cardiovascular events can not be justified. Andreeva and colleagues, as well as Giltay and colleagues, both showed no significant difference in depressive symptoms in patients post-cardiovascular event supplemented with n-3 fatty acids assessed by the GDS-15.4,5 However, Tajalizadekhoob et al. showed n-3 fatty acid supplementation in elderly patients with diagnosed depression does in fact improve their depressive symptoms with a NNT of 8. 6 Although the total patient number of this study was small, further investigation should continue as this proves there is lead way for the use of n-3 fatty acids for their effect in depression
How Economic Distribution Impacts Human Rights on an International Level: A Case Study in Africa and the Balkans
Data from Reporters Without Borders and the World Bank was used in this small case study to assess correlations between economic dispersion, freedom of the press, and measures of gender equality in eight countries. These countries were selected from two regions, with four from both Africa and the Balkans to total eight: Angola, Bulgaria, Czech Republic, Romania, Seychelles, Sierra Leone, Slovenia, and Zimbabwe. The regions were selected to account for any regional trends affecting the data. These countries were selected based on their Gini Coefficients with the hopes of identifying correlations between economic distribution and their measures of human rights. By doing research into how Gini Coefficients are correlated with measures of 3 human rights, we can more fully understand how economic conditions impact an individual’s personal freedoms on a macro level. In other words, understanding how a country’s economic distribution directly impacts its citizens’ abilities to exist with freedom and dignity is important, and this research hopes to examine this issue. This research produced statistically significant research showing correlations between economic dispersion within a state and that state’s human rights measures. This shows that the economic distribution within a country has a direct impact on how protected their human rights are, which is a finding relevant to everyone participating in a capitalist state. This could be used as the foundation for further research with a larger sample size to apply this regional analysis to the global scale
A Role for Neuronal Nicotinic Acetylcholine Receptors in Dopamine-Mediated Behaviors and the Hypnotic Response to Anesthetics: A Dissertation
Neuronal nicotinic acetylcholine receptors (nAChRs) are ligand-gated cation channels that most notably influence dopamine (DA) release. In this thesis, I examine the role of nAChRs in mediating DA-related behaviors such as movement and drug dependence. To accomplish this, I utilized a “gain-offunction” knock-in mouse (the Leu9’Ala line) containing agonist-hypersensitive α4* nAChRs (* indicates other nAChR subunits in addition to α4 are within the receptor complex) that renders receptors 50-fold more sensitive to nicotine and acetylcholine than wild-type (WT) receptors. I found that DHβE, a selective antagonist for α4β2* nAChRs, induced reversible and robust motor dysfunction characterized by hypolocomotion, akinesia, catalepsy, tremor, and clasping in Leu9’Ala but not WT mice. Reversal of the phenotype was achieved by targeting dopamine signaling. Blockade of mutant α4* nAChRs elicited activation of brain regions in the basal ganglia including dorsal striatum and substantia nigra pars reticulata indicated by c-Fos immunoreactivity. These data indicate that blocking α4* nAChRs in Leu9’Ala mice activates the indirect motor pathway resulting in a motor deficit. We also determined that α4* nAChRs involved in motor behaviors did not contain the α6 subunit, a nAChR subunit highly expressed in DAergic neurons suggesting that different nAChR subtypes modulating striatal DA release have separate functions in motor output. Conditioned place aversion and hypolocomotion, behaviors elicited during nicotine withdrawal, were also induced by DHβE in nicotine-naïve Leu9’Ala but not WT mice. Together these data suggest that DHβE globally reduces DA release in the CNS. In a separate project, I determined that α4* and α6* nAChRs modulate drug-induced hypnosis. Activation of nAChRs increased sensitivity to ketamine-induced hypnosis; whereas antagonizing nAChRs had the opposite effect. Additionally, α4 knockout (KO) mice were less sensitive to the hypnotic effects of ketamine, but α6 KO were more sensitive. High doses of ethanol induce an anesthesia-like state characterized by immobility, analgesia, and hypnosis. Testing the effects of ethanol hypnosis in α4 KO revealed that α4* nAChR do not play a large role in the acute effects of ethanol-induced hypnosis, but are involved in tolerance to this ethanol-induced behavior. The mechanisms of anesthetic-induced hypnosis are still largely unclear, despite the wide use of anesthesia. Future work on these receptors and their involvement in the anesthetic response will help to define a mechanism for hypnosis and improve the use of anesthetic drugs
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