The effects of losartan and diazepam on emotional processing

Given the prevalence and substantial economic costs of anxiety disorders, and the shortcomings of current treatments, there is dire need for research that helps inform the development of new treatments and medications. The aim of this thesis was to further our understanding of the effects of two medications relevant to anxiety, losartan and diazepam, to help inform the use of existing treatments and lead to more effective ones. Research has indicated that the angiotensin receptor antagonist losartan may potentially be a promising candidate to enhance the efficacy of exposure-based therapies. It however remains to be fully clarified how losartan affects some of the mechanisms relevant to exposure success. In the first study, a single dose of losartan was shown to increase activation in the paracingulate gyrus, insular cortex, lingual gyrus, and fusiform gyrus in healthy, high trait anxious volunteers, which possibly reflects modulation of higher-order visual processing. There was however no evidence found for an effect of losartan on neural responses in the hippocampus during non-emotional memory encoding. Losartan was also shown to increase positive attentional bias, which was reflected in attention being more firmly held by positive stimuli compared to neutral stimuli. Given that both greater reactivity in higher-order visual regions and positive valence training have been shown to be relevant for therapy success, these results may provide further support that losartan might potentially have synergistic effects with exposure therapy, but this remains to be tested directly. The most common pharmacological treatments for anxiety disorders include selective serotonin reuptake inhibitors and benzodiazepines, but both groups of medications have limitations. A better understanding of how existing medications exert their anxiolytic effects may help guide development of new medications. As benzodiazepines are not effective in treating depression, researching their effects provide a means of teasing apart antidepressant and anxiolytic effects. A comprehensive understanding of the cognitive neuropsychological mechanisms behind their anxiolytic effects is still lacking. In the second study, a 7-day treatment of diazepam was shown to lower connectivity between the amygdala and the pre- and post-central gyrus during cognitive reappraisal, and between limbic regions and the precuneous cortex in response to aversive pictures in healthy volunteers. The treatment also led to a decrease in activation in the right vlPFC during reappraisal, and to an increase in activation in the left vlPFC and right ACC in response to positive stimuli, without any subjective changes in mood and state anxiety. Diazepam may thus potentially be exerting its short-term anxiolytic effects by modulating activity within these brain areas. Taken together, these findings provide valuable insights into potential mechanisms through which diazepam and losartan may exert their therapeutic effects. A better understanding of these mechanisms can hopefully help inform the development of future anxiolytics and combination treatments

Wind-tunnel study of wind loads on Lajet Solar Collector Module

CER85-86STT-JAP-JEC12.CSU Project 2-96350.Includes bibliographical references (pages 23).November 1985.For LaJet Energy Company

Wind-tunnel study of wind frame loads on Broad Financial Center, New York

CER84-85JAP-STT-JEC22.Includes bibliographical references (page 13).December 1984.CSU Project 2-96080.For Fox and Fowle Architects, P. C

Projectile-shape dependence of impact craters in loose granular media

We report on the penetration of cylindrical projectiles dropped from rest into a dry, noncohesive granular medium. The cylinder length, diameter, density, and tip shape are all explicitly varied. For deep penetrations, as compared to the cylinder diameter, the data collapse onto a single scaling law that varies as the 1/3 power of the total drop distance, the 1/2 power of cylinder length, and the 1/6 power of cylinder diameter. For shallow penetrations, the projectile shape plays a crucial role with sharper objects penetrating deeper.Comment: 3 pages, 3 figures; experimen

Antibubbles and fine cylindrical sheets of air

Drops impacting at low velocities onto a pool surface can stretch out thin hemispherical sheets of air between the drop and the pool. These air sheets can remain intact until they reach submicron thicknesses, at which point they rupture to form a myriad of microbubbles. By impacting a higher-viscosity drop onto a lower-viscosity pool, we have explored new geometries of such air films. In this way we are able to maintain stable air layers which can wrap around the entire drop to form repeatable antibubbles, i.e. spherical air layers bounded by inner and outer liquid masses. Furthermore, for the most viscous drops they enter the pool trailing a viscous thread reaching all the way to the pinch-off nozzle. The air sheet can also wrap around this thread and remain stable over an extended period of time to form a cylindrical air sheet. We study the parameter regime where these structures appear and their subsequent breakup. The stability of these thin cylindrical air sheets is inconsistent with inviscid stability theory, suggesting stabilization by lubrication forces within the submicron air layer. We use interferometry to measure the air-layer thickness versus depth along the cylindrical air sheet and around the drop. The air film is thickest above the equator of the drop, but thinner below the drop and up along the air cylinder. Based on microbubble volumes, the thickness of the cylindrical air layer becomes less than 100 nm before it ruptures

Coherent turbulent structures in a rapid contraction

The coherent vortical structures in turbulent flow through a strong 16:1 3-D contraction, are studied using time-resolved volumetric measurements. Visualization using vorticity magnitude criterion shows the emergence of long, stretched cylindrical vortices aligned with the mean flow. This alignment is quantified by PDFs of the direction cosines. We propose two measures to quantify the alignment, the peak height in the probability and a coefficient from the moment of the PDF, both of which reaffirm the strong streamwise alignment. The r.m.s. streamwise vorticty grows within the contraction to becoming 4.5 times larger than the transverse component, at the downstream location where the contraction ratio C=11. The characteristic vortices become as long as the measurement volume, or more than 4 times the integral scale at the entrance to the contraction. We also characterize the vorticity enhancement along individual vortices, measuring 65% strengthening over the distance where C goes from 4 to 11. The prevalence of these coherent structures is estimated from 700,000 measured volumes, showing that near the outlet it is more likely to have 1 or 2 of these structures present than none

Theory of the collapsing axisymmetric cavity

We investigate the collapse of an axisymmetric cavity or bubble inside a fluid of small viscosity, like water. Any effects of the gas inside the cavity as well as of the fluid viscosity are neglected. Using a slender-body description, we show that the minimum radius of the cavity scales like $h_0 \propto t'^{\alpha}$, where $t'$ is the time from collapse. The exponent $\alpha$ very slowly approaches a universal value according to $\alpha=1/2 + 1/(4\sqrt{-\ln(t')})$. Thus, as observed in a number of recent experiments, the scaling can easily be interpreted as evidence of a single non-trivial scaling exponent. Our predictions are confirmed by numerical simulations

Two cases of spontaneous regression of metastasis secondary to renal cell carcinoma

Neðst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenSpontaneous regression of metastatic renal cell carcinoma is a rare but well documented event, most often involving pulmonary metastasis. Two cases involving brain and pleural metastasis are presented. In both cases nephrectomy was the only treatment.Sjálfkrafa hvarf meinvarpa nýrnafrumukrabbameins er sjaldséð fyrirbæri. Hér er lýst tveimur tilfellum sem vitað er með vissu að hafi greinst hér á landi. Annars vegar er um að ræða sjálfkrafa hvarf meinvarpa í heila og hins vegar í fleiðru. Báðir sjúklingarnir eru á lífi í dag við góða heilsu, 17 og 11 árum eftir greiningu meinvarpann

Local properties of extended self-similarity in 3D turbulence

Using a generalization of extended self-similarity we have studied local scaling properties of 3D turbulence in a direct numerical simulation. We have found that these properties are consistent with lognormal-like behavior of energy dissipation fluctuations with moderate amplitudes for space scales $r$ beginning from Kolmogorov length $\eta$ up to the largest scales, and in the whole range of the Reynolds numbers: $50 \leq R_{\lambda} \leq 459$. The locally determined intermittency exponent $\mu(r)$ varies with $r$; it has a maximum at scale $r=14 \eta$, independent of $R_{\lambda}$.Comment: 4 pages, 5 figure