Bubble Simulation Using Level Set-Boundary Element Method

In bubble dynamics, an underwater bubble may evolve from being singly-connected to being toroidal. Furthermore, two or more individual bubbles may merge to form a single large bubble. These dynamics involve significant topological changes such as merging and breaking, which may not be handled well by front-tracking boundary element methods. In the level set method, topological changes are handled naturally through a higher-dimensional level set function. This makes it an attractive method for bubble simulation. In this paper, we present a method that combines the level set method and the boundary element method for the simulation of bubble dynamics. We propose a formulation for the update of a potential function in the level set context. This potential function is non-physical off the bubble surface but consistent with the physics on the bubble surface. We consider only axisymmetric cavitation bubbles in this paper. Included in the paper are some preliminary results and findings.Singapore-MIT Alliance (SMA

Acceleration of Gas Bubble-Free Surface Interaction Computation Using Basis Preconditioners

The computation of gas bubble-free surface interaction entails a time-stepping algorithm whereby a linear system is solved at each time-iteration. In our investigation, the linear systems are derived from a desingularized boundary integral formulation and are poorly conditioned. This leads to poor convergence rates when Krylov subspace methods are used to solve these systems. The convergence rates may however be improved with proper preconditioning. We limit our investigation to gas bubbles initiated at depths sufficiently small such that a spike forms on the free surface during the later stages of evolution. Bubble dynamics dictate that for gas bubbles initiated at such depths, the stages through which the gas bubble and free surface evolve are similar. Based on this fact, we propose to perform one computation run for a gas bubble initiated at one particular depth, obtain a judicious set of a priori basis preconditioners from this run and thereafter, use this set of preconditioners on computation runs for gas bubble initiated at different depths. The computation time taken by the proposed method is, in general, 50% and 20% of the time taken by the present method (without preconditioning) with terminating criteria of 1.0e-5 and 1.0e-7 in the infinity-norm respectively using the Bi-conjugate Gradient Stabilized solver. The present method further enables computation to an infinity-norm terminating criterion of 1.0e-10 in a shorter time compared to the present method with a criterion of 1.0e-5.Singapore-MIT Alliance (SMA

Parenting Styles of The Kadazandusun Community in Rural Areas of Sabah in Ensuring Child’s Success in School

Today, many KadazanDusun children who live in rural areas, whose parents are without educational background and earn a living as farmers, have successfully entered public tertiary level education institutions (IPTA) or private tertiary level education institutions (IPTS). This development has prompted this study to identify the parenting styles involved in ensuring the success of children in school and thus succeeding in furthering to tertiary level. For data collection, this study choses the qualitative approach. Thus, to obtain the required data, interviews were carried out with parents who have more than one child studying at IPTA/IPTS, self-employed in their hometown and had no opportunity to formal education. The respondents were chosen through purposive and snowball selection. The findings show that both authoritarian and authoritative parenting styles are practiced by the KadazanDusun parents in ensuring that children are successful in school. The children who were also interviewed agreed these styles are practiced because of the difficulties in the parents’ lives due to the lack of good education. Therefore, the parents want to ensure their children to succeed in their education for a better future. The parents do not want their economic problems which they are facing now to be inherited by their children

Potential Use of Morphological Characteristics in Evaluating Natural Variation of “Barako” Seedlings

The Philippines is one of only three countries able to produce Coffea liberica and grow two other species of coffee, Coffea canephora, Coffea arabica. Coffea liberica, or “Barako,” is the least cultivated of coffee species. Its unique taste has high potential to grow in the market if production was increased. However, the 2020 Taal Volcano eruption resulted in thousands of damaged Barako trees in 2020 and 2021. As new seedlings are produced, the question of variety among planting material comes up. Farmers need a method to evaluate natural differences of current Barako trees, to answer whether seedlings from farms cultivating Barako are naturally different. This research aims to determine if the morphological characteristics of cultivated seedlings from different farms can be classified through image and statistical analysis. Basic knowledge on how varieties―which producedifferent flavors, aroma, and market value of coffee―differ among farms is needed for a strategy to increase the number of seedlings. This study’s initial data set indicated statistically significant differences in the average seedling height per node and the leaf area per length of 31, 10-month old coffee seedlings from two different farms, grown in a common environment. The process may be developed further for use in evaluating natural variation among C. liberica as seedlings

Nonoperative Korean Medicine Combination Therapy for Lumbar Spinal Stenosis: A Retrospective Case-Series Study

This is a retrospective case series exploring the therapeutic benefits and harm of nonoperative Korean medicine combination therapy for lumbar spinal stenosis (LSS). The medical records of a total of 33 LSS patients, who were treated as inpatients at Mokhuri Neck and Back Hospital, Republic of Korea, from November 2010 to January 2012, were reviewed first and telephone survey on these patients was conducted after one year. Body acupuncture, pharmacoacupuncture, Chuna, and oral administration of herbal medicines were offered to all patients. A Visual analogue scale (VAS) of pain and the walking duration without pain were used to assess the patients during the approximately 1-month treatment period. The average VAS score of pain and the walking duration improved significantly; the VAS score decreased from 9 (SD, 1.15) to 2.75 (2.22) (p<0.01), and the walking duration increased from 5.5 (6.66) to 16.75 (13.00) minutes (p<0.01). No adverse event was reported during the treatment. In addition, the decreased pain level and improved function continued for over one year. Although we did not find definitive evidence, the study results suggest that KM combination therapy may be beneficial for decreasing pain and improving function in LSS patients and may produce comparatively few adverse events

Phantom Acupuncture Induces Placebo Credibility and Vicarious Sensations: A Parallel fMRI Study of Low Back Pain Patients

Although acupuncture is an effective therapeutic intervention for pain reduction, the exact difference between real and sham acupuncture has not been clearly understood because a somatosensory tactile component is commonly included in the existing sham acupuncture protocols. In an event-related fMRI experiment, we implemented a novel form of sham acupuncture, phantom acupuncture, that reproduces the acupuncture needling procedure without somatosensory tactile stimulation while maintaining the credibility of the acupuncture treatment context. Fifty-six non-specific low back pain patients received either real (REAL) or phantom (PHNT) acupuncture stimulation in a parallel group study. The REAL group exhibited greater activation in the posterior insula and anterior cingulate cortex, reflecting the needling-specific components of acupuncture. We demonstrated that PHNT could be delivered credibly. Interestingly, the PHNT-credible group exhibited bilateral activation in SI/SII and also reported vicarious acupuncture sensations without needling stimulation. The PHNT group showed greater activation in the bilateral dorsolateral/ventrolateral prefrontal cortex (dlPFC/vlPFC). Moreover, the PHNT group exhibited significant pain reduction, with a significant correlation between the subjective fMRI signal in the right dlPFC/vlPFC and a score assessing belief in acupuncture effectiveness. These results support an expectation-related placebo analgesic effect on subjective pain intensity ratings, possibly mediated by right prefrontal cortex activity

Liprin-α4 Is Required for Nickel Induced Receptor Protein Tyrosine Phosphatase-Leukocyte Antigen Related Receptor F (RPTP-LAR) Activity

Liprin-α4 was strongly induced following nickel (II) chloride exposure in a variety of cell types including BEAS-2B, A549, BEP2D and BL41 cells. Liprin-α4, a member of the Liprin alpha family, has seven isoforms but only three of these variants were detected in BEAS-2B cells (004, 201 and 202). The level of Liprin-α4 variants 201 and 004 were highly increased in BEAS-2B cells in response to nickel. We showed that Liprin-α4 bound directly to the cytoplasmic region of RPTP-LAR (receptor protein tyrosine phosphatase-leukocyte antigen-related receptor F). The cytoplasmic region of RPTP-LAR contains two phosphatase domains but only the first domain shows activity. The second domain interacts with other proteins. The phosphatase activity was increased both following nickel treatment and also in the presence of nickel ions in cell extracts. Liprin-α4 knock-down lines with decreased expression of Liprin-α4 variants 004 and 201 exhibited greater nickel toxicity compared to controls. The RPTP-LAR phosphatase activity was only slightly increased in a Liprin-α4 knock-down line. Liprin-α4 appeared necessary for the nickel induced tyrosine phosphatase activity. The presence of Liprin-α4 and nickel increased tyrosine phosphatase activity that reduced the global levels of tyrosine phosphorylation in the cell

Search for the neutral Higgs bosons of the minimal supersymmetric standard model in pp collisions at root s=7 TeV with the ATLAS detector

A search for neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) is reported. The analysis is based on a sample of proton-proton collisions at a centre-of-mass energy of 7TeV recorded with the ATLAS detector at the Large Hadron Collider. The data were recorded in 2011 and correspond to an integrated luminosity of 4.7 fb-1 to 4.8 fb-1. Higgs boson decays into oppositely-charged muon or τ lepton pairs are considered for final states requiring either the presence or absence of b-jets. No statistically significant excess over the expected background is observed and exclusion limits at the 95% confidence level are derived. The exclusion limits are for the production cross-section of a generic neutral Higgs boson, φ, as a function of the Higgs boson mass and for h/A/H production in the MSSM as a function of the parameters mA and tan β in the mhmax scenario for mA in the range of 90GeV to 500 GeV. Copyright CERN

Oxidative stress as mechanism of neurotoxicity of ethanol and halluzinogenic amphetamines

Der Konsum von halluzinogenen Amphetaminen wie MDMA („Ecstasy“), MDA („Love“) und MDE („Eve“) ist unter Jugendlichen, insbesondere in der „Clubscene“ weit verbreitet. Hierbei werden die so genannten „Partydrogen“ vor allem in Verbindung mit Alkohol eingenommen. Die Amphetaminderivate können schwere neurologische Symptome verursachen. Ziel der vorliegenden Arbeit war es, die unmittelbaren Auswirkungen einer Belastung mit den psychotropen Substanzen Ethanol und halluzinogenen Amphetaminen auf Zellen des Zentralnervensystems unter besonderer Berücksichtigung von oxidativem Stress zu untersuchen. Die Experimente wurden in vitro an der neuronalen Zelllinie HT22 durchgeführt. Die Zellen wurden mit Ethanol bzw. den Amphetaminderivaten MDMA, MDA und MDE belastet. Liponsäure, Vitamin C, Vitamin E, Katalase, N-Acetylcystein und Desferal wurden als Antioxidantien zugesetzt. Die Vitalität der HT22 Zellen wurde mittels der Trypanblau-Methode bestimmt. Zum Nachweis von oxidativem Stress wurden Proteincarbonyle und Malondialdehyde gemessen. Bei der Belastung der HT22 Zellen mit Ethanol zeigte sich ein linearer Abfall vitaler Zellen. Es kam zu einem Anstieg der Proteincarbonyle und des Malondialdehyd. Bei Zusatz von antioxidativen Substanzen wurde eine Abschwächung dieser Effekte deutlich. Bei der Belastung der HT22 Zellen mit den Amphetaminderivaten kam es analog zu einem Abfall der vitalen Zellen. Die Proteincarbonyle stiegen dosisabhängig signifikant. Auch der Marker für die Lipidperoxidation stieg, wenngleich nicht signifikant. Durch den Zusatz antioxidativer Substanzen konnten diese Effekte reduziert werden. Bei der Kombinationsbelastung der HT22 Zellen mit Ethanol und MDMA kam es zu einer Verstärkung der zytotoxischen Effekte der Einzelbelastung. Auch hierbei konnte durch Zugabe antioxidativer Substanzen eine Reduktion der Zytotoxizität erreicht werden. Zusammengefasst zeigt die vorliegende Arbeit, dass halluzinogene Amphetamine dosisabhängig toxische Effekte auf neuronale HT22 Zellen haben. Diese Effekte werden zumindest partiell durch oxidativen Stress vermittelt und werden durch kombinierte Belastung mit Ethanol noch verstärkt. Die gleichzeitige Gabe von Antioxidantien kann diesen toxischen Effekten entgegenwirken. Die protektive Wirkung von Antioxidantien auf neuronale Zellen kann sich bei der Entwicklung neuer Therapien von Patienten mit Drogenintoxikationen als wichtig erweisen und sollte in weiteren Studien verifiziert werden.The consumption of hallucinogenic amphetamines such as MDMA (“ecstasy”), MDA (“love”) and MDE (“eve”) is still popular among adolescents, in particular in the “club scene”. These so-called party drugs are often taken in combination with alcohol. The amphetamine derivates can cause serious neurologic symptoms. The intention of this work was to analyze the effects of the psychotropic substances ethanol and hallucinogenic amphetamines on cells of the central nervous system and was focused on the detection of oxidative stress. For the in vitro experiments we used HT22 cells. The cells were incubated with ethanol and the amphetamine derivates MDMA, MDA and MDE respectively. Lipoic acid, vitamin C, vitamin E, catalase, N-acetylcysteine and desferal were added as antioxidants. The vitality of the HT22 cells was evaluated using trypan blue staining. Oxidative stress was verified by protein carbonyl content and malondialdehyde content. Incubation of the HT22 cells with ethanol caused a linear decline of vital cells. The protein carbonyl content and the malondialdehyde increased. By adding antioxidants these effects were attenuated significantly. An analog decline of vital cells was caused by incubation of HT22 cells with the amphetamine derivates. The protein carbonyl content increased significantly in a dose-dependent manner. The marker for lipid peroxidation also rised, but not significantly. By the addition of antioxidative substances these cytotoxic effects could be reduced. Co- incubation of HT22 cells with ethanol and MDMA increased the cytotoxic effects of the isolated substances. These cytotoxic effects could be reduced by the addition of antioxidative substances as well