Furosemide-induced vasodilation: Importance of the state of hydration and filtration

Furosemide-induced vasodilation: Importance of the state of hydration and filtration. The circumstances under which furose-mide increases renal blood flow was examined in mongrel dogs as it may relate to a tubuloglomerular feedback mechanism. Two maneuvers, desoxycorticosterone (DOCA) plus salt treatment and inhibition of tubular fluid flow, were used in the dogs to evaluate the renal vascular effects of furosemide because these maneuvers have been reported to blunt the tubuloglomerular feedback in micropuncture studies. In addition, we also used two structurally different nonsteroidal antiinflammatory drugs to assess the importance of prostaglandins to achieve furosemide's renal vasodilation. Furosemide (5 mg/kg, i.v.) increased renal blood flow in volume-depleted animals from a baseline flow of 141 ± 28ml/min to a maximum of 176 ± 35ml/min at 6min after furosemide administration. If the animals were pretreated with a high-salt diet and i.m. DOCA for 5 days, furosemide administration produced no renal vascular effects but still caused a large diuresis, and these dogs still had a responsive renal vascular bed to infused prostaglandin E2. In addition, kidneys rendered non-filtering in volume-depleted animals had no renal vascular response to furosemide. Volume-depleted animals, pretreated with either indomethacin or sodium meclofenamate, did not have a renal vascular response to furosemide although they did have a diuretic response and a responsive renal vasculature to prostaglandin E2. From our data, we hypothesize that the renal vascular response to furosemide is secondary to a tubular mechanism mediated by a vasodilatory prostaglandin. Because furosemide has been shown to disrupt the tubuloglomerular feedback mechanism, and the two maneuvers, DOCA plus salt treatment and lack of filtration, blunt the tubuloglomerular feedback response as well as inhibit the renal vascular response to furosemide, we further hypothesize that furosemide-induced renal vasodilation may be secondary to the disruption of an active tubuloglomerular feedback mechanism.Vasodilatation induite par le furosémide: Importance de l'état d'hydratation et de filtration. Les circonstances où le furosémide augmente le débit sanguin rénal ont été étudiées chez des chiens bâtards en fonction d'un mécanisme possible de rétro-contrôle tubulo-glomérulaire. Deux manoeuvres, le traitement par la désoxycorticosterone (DOCA) et le sel et l'inhibition du débit tubulaire, ont été utilisées chez des chiens pour évaluer les effets vasculaires rénaux du furosemide, puisque ces deux manoeuvres sont réputées effacer le rétro-contrôle tubulo-glomérulaire dans les études par microponction. De plus, nous avons employé deux drogues anti-inflammatoires, non stéroïdiennes, de structures différentes pour évaluer l'importance des prostaglandines dans le déterminisme d'une vasodilatation rénale. Le furosemide (5 mg/kg, i.v.) augmente le débit sanguin rénal chez les animaux déshydratés à partir d'une ligne de base de 141 ± 28ml/min jusqu'à un maximum de 176 ± 35ml/min 6 minutes après l'administration de furosémide. Quand les animaux ont été prétraités par une alimentation riche en sel et de la DOCA i.m. pendant 5 jours l'administration de furosémide n'a pas produit d'effets vasculaires rénaux mais a cependant déterminé une diurèse importante et le lit vasculaire rénal de ces chiens pouvait encore répondre à la perfusion de prostaglandines E2. De plus, des reins devenus non filtrants chez des animaux déshydratés n'avaient pas de réponse vasculaire rénale au furosémide. Les animaux déshydratés et pré-traités soit par l'indométhacine, soit par le méclofénamate de sodium, n'avaient pas de réponse vasculaire rénale au furosémide quoiqu'ils avaient une réponse diurétique et une réponse vasculaire rénale à la prostaglandin E2. De ces résultats nous tirons l'hypothèse que la réponse vasculaire rénale au furosémide est secondaire à un mécanisme tubulaire dont la vasodilatation par la prostaglandine est un médiateur. Puisqu'il a été montré que le furosemide supprime le rétro-contrôle tubulo-glomérulaire et que les deux manoeuvres, DOCA et sel, d'une part, absence de filtration, d'autre part, annulent le rétro-contrôle tubulo-glomérulaire de même qu'elles inhibent la réponse vasculaire rénale au furosémide, nous faisons l'hypothèse supplémentaire que la vasodilatation rénale induite par le furosémide peut être secondaire à l'interruption d'un mécanisme actif de rétro-contrôle tubulo-glomérulaire

EQUAL VOTES, EQUAL MONEY:COURT-ORDERED REDISTRICTING AND THE DISTRIBUTION OFPUBLIC EXPENDITURES IN THE AMERICAN STATES

A study of the effects of legislative re-districting in the states during the 1960's. Also contains data fil

The Power Control Rack: A Modular Solution for Building Power Systems

LDRD proposal presentation to ETA ALD at LBNL. Proposing use of SST to create a modular efficient single point of common coupling for buildings

Do Perceptions of Ballot Secrecy Influence Turnout? Results from a Field Experiment

Although the secret ballot has long been secured as a legal matter in the United States, formal secrecy protections are not equivalent to convincing citizens that they may vote privately and without fear of reprisal. We present survey evidence that those who have not previously voted are particularly likely to voice doubts about the secrecy of the voting process. We then report results from a field experiment where we provided registered voters with information about ballot secrecy protections prior to the 2010 general election. We find that these letters increased turnout for registered citizens without records of previous turnout, but did not appear to influence the behavior of citizens who had previously voted. These results suggest that although the secret ballot is a long-standing institution in the United States, providing basic information about ballot secrecy can affect the decision to participate to an important degree.

The Persuasive Effects of Direct Mail: A Regression Discontinuity Approach

During the contest for Kansas attorney general in 2006, an organization sent out 6 pieces of mail criticizing the incumbent's conduct in office. We exploit a discontinuity in the rule used to select which households received the mailings to identify the causal effect of mail on vote choice and voter turnout. We find these mailings had both a statistically and politically significant effect on the challenger's vote share. Our estimates suggest that a ten percentage point increase in the amount of mail sent to a precinct increased the challenger's vote share by approximately three percentage points. Furthermore, our results suggest that the mechanism for this increase was persuasion rather than mobilization.

People vote because they’re worried others will think less of them if they don’t.

For many, the benefits of voting are not immediately obvious. So why do people turn out on Election Day? Some have suggested that people vote because they are worried that others will view them less favorably if they do not. Using experimental evidence from a national survey, David Doherty, Gregory Huber, Alan Gerber and Conor Dowling set out to test this theory. Their results suggest that people’s expectations that others will think less of them if they fail to vote are well-founded

Seasonal Variability of the Polar Stratospheric Vortex in an Idealized AGCM with Varying Tropospheric Wave Forcing

The seasonal variability of the polar stratospheric vortex is studied in a simplified AGCM driven by specified equilibrium temperature distributions. Seasonal variations in equilibrium temperature are imposed in the stratosphere only, enabling the study of stratosphere–troposphere coupling on seasonal time scales, without the complication of an internal tropospheric seasonal cycle. The model is forced with different shapes and amplitudes of simple bottom topography, resulting in a range of stratospheric climates. The effect of these different kinds of topography on the seasonal variability of the strength of the polar vortex, the average timing and variability in timing of the final breakup of the vortex (final warming events), the conditions of occurrence and frequency of midwinter warming events, and the impact of the stratospheric seasonal cycle on the troposphere are explored. The inclusion of wavenumber-1 and wavenumber-2 topographies results in very different stratospheric seasonal variability. Hemispheric differences in stratospheric seasonal variability are recovered in the model with appropriate choices of wave-2 topography. In the model experiment with a realistic Northern Hemisphere–like frequency of midwinter warming events, the distribution of the intervals between these events suggests that the model has no year-to-year memory. When forced with wave-1 topography, the gross features of seasonal variability are similar to those forced with wave-2 topography, but the dependence on forcing magnitude is weaker. Further, the frequency of major warming events has a nonmonotonic dependence on forcing magnitude and never reaches the frequency observed in the Northern Hemisphere.United States. National Aeronautics and Space Administration (Grant NNX13AF80G

Does Church Attendance Cause People to Vote? Using Blue Laws' Repeal to Estimate the Effect of Religiosity on Voter Turnout

Regular church attendance is strongly associated with a higher probability of voting. It is an open question as to whether this association, which has been confirmed in numerous surveys, is causal. We use the repeal of the laws restricting Sunday retail activity ("Blue laws") to measure the effects of church-going on political participation. The repeal of Blue Laws caused a 5 percent decrease in church attendance. We measure the effect of Blue Laws' repeal on political participation and find that following the repeal turnout falls by approximately 1 percentage point. This turnout decline, which is statistically significant and fairly robust across model specifications, is consistent with the large effect of church attendance on turnout reported in the literature, and suggests that church attendance may have significant causal influence on voter turnout.

Real-Time Detection for Scattering Scanning Near-Field Optical Microscopy

Scattering scanning near-field optical microscopy (s-SNOM) is a powerful technique for measuring spectroscopic properties of materials with spatial resolution previously unobtainable due to the diffraction limit. s-SNOM combines scanning probe microscopy (SPM) with spectroscopy to provide sub-diffraction limited spatial resolution information about optical and related properties of matter. Discriminating the weak elastic s-SNOM signal from various undesirable background signals is critical to the success of s-SNOM as a measurement technique. Traditionally this discrimination is achieved through lock-in detection, in which the s-SNOM signal is restricted to, and measured at harmonics of an atomic force microscope tip oscillation frequency Ω. However, this detection technique neglects information at all undetected harmonics. To overcome this loss of information, for my honors thesis, I developed a new s-SNOM detection scheme based upon the real-time acquisition of the s-SNOM signal to ensure no information is lost. With this new detection scheme I have been able to simulate gated detection elastic s-SNOM –a measurement which has not yet been realized experimentally– and determine that it provides no more than background-ridden information readily obtainable with lock-in detection. I have also been able to generate, for the first time, an experimental reconstruction of the distance dependence of the tip-sample interaction for elastic s-SNOM measurements and compare it to theoretical models