Bubble Pinch-Off in a Rotating Flow

We create air bubbles at the tip of a “bathtub vortex” which reaches to a finite depth. The bathtub vortex is formed by letting water drain through a small hole at the bottom of a rotating cylindrical container. The tip of the needlelike surface dip is unstable at high rotation rates and releases bubbles which are carried down by the flow. Using high-speed imaging we find that the minimal neck radius of the unstable tip decreases in time as a power law with an exponent close to 1/3. This exponent was found by Gordillo et al. [Phys. Rev. Lett. 95, 194501 (2005)] to govern gas flow driven pinch-off, and indeed we find that the volume oscillations of the tip creates a considerable air flow through the neck. We argue that the Bernoulli pressure reduction caused by this air flow can become sufficient to overcome the centrifugal forces and cause the final pinch-off

Scalarane-Based Sesterterpenoid RCE-Protease Inhibitors Isolated from the Indonesian Marine Sponge Carteriospongia foliascens

part of research collaboration between Mar Fish Faculty of Unhas and EOS UBCTwo new 20,24-bishomo-25-norscalaranes, compounds 1 and 2, and two new and two known 20,24-bishomoscalaranes, compounds 3???6, have been isolated from the Indonesian marine sponge Carteriospongia foliascens. The structures of 1???6 were determined by spectroscopic analysis. Compounds 1 and 3???6 inhibit RCE-protease activity

Estsitalopraami efektiivsus depressiooni ravis võrrelduna konventsionaalsete selektiivsete serotoniini tagasihaarde inhibiitorite ja venlafaksiin XRiga: metaanalüüs

Estsitalopraam on kõige selektiivsem selektiivsete serotoniini tagasihaarde inhibiitorite rühma kuuluv antidepressant. Varasemad uuringud on näidanud, et estsitalopraam on oma toimelt tõhusam kui tsitalopraam. Artiklis on antud ülevaade metaanalüüsi uuringutest, milles estsitalopraami võrreldi teiste antidepressantidega (tsitalopraam, fluoksetiin, paroksetiin, sertraliin ja venlafaksiin XR). Estsitalopraam oli efektiivsem kui kõik teised võrdlusravimid nii üldise raviefekti, ravile reageerimise määra kui ka remissiooni saavutamise määra poolest. Eri ravimirühmade analüüs näitas, et estsitalopraam oli oluliselt tõhusam kui konventsionaalsed SSRId ja võrdväärne venlafaksiiniga, ehkki uuringu üldised tulemused ei näita tingimata, et estsitalopraam oleks oluliselt efektiivsem kui iga SSRI eraldi. Sarnased tulemused leiti ka raske depressiooniga patsientide seas. Eesti Arst 2006; 85 (11): 739–75

Path planning and reactive based control for a quadrotor with a suspended load

This paper presents a solution to quadrotor cargo transportation, more precisely when cargo is suspended as a sling load. The challenge lies in payload position control and swing attenuation, which we approach by dividing the model into subsystems: attitude quadrotor in free flight, and translational and attitude load dynamics. We propose a solution based on reactive control, in the sense that we utilize a reactive force that reacts to the error position and the oscillation in the load. Asymptotic stability of the system's closed-loop equilibrium is proved using Lyapunov theory. Additionally, a three-dimensional path planning algorithm is proposed based on cubic splines, which give us a natural path between initial and final desired points. Moreover, we convert the path planning problem into trajectory tracking with a spline's correct parametrization. Control and path planning performance are demonstrated with numerical simulations in three different scenarios

Latonduines A and B, New Alkaloids Isolated from the Marine Sponge Stylissa carteri:??? Structure Elucidation, Synthesis, and Biogenetic Implications

Part of research collaboration results between Fac Mar Fish UNHAS and EOS UBCLatonduines A (6) and B (7), two new alkaloids with unprecedented heterocyclic skeletons, have been isolated from the Indonesian marine sponge Stylissa carteri. The structures of the latonduines were elucidated by analysis of spectroscopic data and confirmed by the total synthesis of latonduine A (6). It is proposed that ornithine is the biogenetic precursor to the aminopyrimidine fragment of the latonduines

GARDINERIN, A BIOLOGICALLY ACTIVE ACETOGENIN FROM THE SRI LANKAN GONIOTHALAMUS GARDINERI HOOK. F. AND THOMSON

Objective: The study was undertaken to isolate biologically active compounds from Goniothalamus gardineri, a plant endemic to Sri Lanka. Methods: Roots and flowers of Goniothalamus gardineri were extracted into dichloromethane and methanol. A new acetogenin, gardinerin isolated by column chromatography of the dichloromethane extract was structurally characterized using NMR and Mass spectroscopies. It was found to be mosquito larvicidal (against 2nd instar larvae of Aedes aegypti), cytotoxic (in the brine shrimp assay) and antioxidant (DPPH assay). Results: Gardinerin exhibited potent mosquitolarvicidal activity (LC50 = 0.0744±0.37 ppm.), cytotoxicity (LC50 = 1.5±0.37 ppm) and antioxidant activity (IC50 =10.02±0.01 ppm). The same extract furnished (5R)-goniothalamin. The hexane extract of the flowers of G. gardineri yielded poriferesterol and stigmast-4, 22-dien-3-one.Conclusion: The endemic plant G. gardineri has yielded an acetogenin possessing highly potent antioxidant, cytotoxic and mosquitolarvicidal activity. Â

The smallest worthwhile effect of primary care physiotherapy did not differ across musculoskeletal pain sites

Objectives: To determine and compare estimates of the smallest worthwhile effect (SWE) for physiotherapy in neck, shoulder, and low-back pain patients and to investigate the influence of sociodemographic, clinical, and psychological factors on these estimates. Methods: A structured telephone interview was conducted before treatment was commenced in 160 patients referred for primary care physiotherapy. The benefit-harm trade-off method was used to estimate the SWE of physiotherapy for the following outcomes; pain, disability, and time to recovery, compared with the improvement achieved without any treatment (natural course). Regression analyses were used to assess the influence of sociodemographics, clinical variables, and intake scores on pain, disability, and psychological scales. Results: The median SWE for improvements on pain and disability was 20% (interquartile range 10%–30%), and the SWE for time to recovery was 10 days (interquartile range 7–14 days) over a period of 6 weeks. These estimates did not differ with respect to pain location (neck, shoulder, or back) and were generally unaffected by sociodemographic, clinical, and psychological factors. Conclusion: People with neck, shoulder, and low-back pain need to see at least 20% of additional improvement on pain and disability compared with natural recovery to consider that the effect of physiotherapy is worthwhile, given its costs, potential side effects, and inconveniences