A Low-Noise Electrically Levitated Oscillator for Investigating Fundamental Physics

This thesis describes the creation of a low-noise, electrodynamically levitated nanoparticle oscillator for applications in optomechanics and quantum physics. The harmonic motion of a nanoparticle trapped in a linear Paul trap was measured and characterized. Velocity damping and parametric feedback cooling methods were implemented to cool the centre-of-mass motion of an oscillator. Experiments were conducted on the same particle so that a direct comparison between both methods could be done. Theory and simulations were developed to fully understand these processes. It was shown that velocity damping achieves lower temperatures due to the greater backaction from measurement noise in the parametric feedback scheme. A minimum temperature of $26\pm6$\,mK was reached in these experiments limited only by detection noise. Low-noise electronics, designed to prevent motional heating of the levitated nanoparticle due to fluctuations in the confining electric fields, were studied. At low pressures down to 3×10⁻⁷ mbar, where minimal thermal noise is present from gas collisions, no heating effect from voltage fluctuations was observed in two of the oscillator modes. This work demonstrated the utility of this trap for future low-noise experiments including investigations into wave function collapse with preliminary results presented here. The cooling and dynamics of two co-trapped nanoparticles strongly coupled by their mutual Coulomb repulsion was also studied. The normal modes in both the axial and radial motion of the trapped nanoparticle were measured and characterized. Sympathetic cooling and squeezing of one particle were achieved through interaction with the other trapped nanoparticle. Temperatures down to 200±10 mK and 190±40 mK were reached in the axial normal modes. Additionally, a measurement-based scheme was used to couple the axial normal modes which were shown to display the characteristics of strong coupling. Energy exchange between the two modes was demonstrated alongside sympathetic cooling of one mode through this coupling

How Indonesia’s election puts global biodiversity at stake with an impending war on palm oil

Almost overnight, Jokowi has transformed from an environmental good-guy — someone who’s battled destructive wildfires and noxious haze, tried to slow palm oil expansion and promoted several other eco-smart measures — into a nationalistic mouthpiece for the oil palm industry. Let’s hope this ‘Dr Jekyll and Mr Hyde’ transformation of Jokowi is temporary — a kind of fleeting election madness that overtakes many politicians in the heat of battle. If not, Indonesia’s forests and the endangered species living in them will be at even more risk

From Australia to Africa, fences are stopping Earth’s great animal migrations

Both of these enormous fences were intended to repel rabbits and other “vermin” such emus, kangaroos and dingoes that were considered threats to crops or livestock. Built over a century ago, their environmental impacts were poorly understood or disregarded at the tim

Playing the odds in clinical decision making: lessons from berry aneurysms undetected by magnetic resonance angiography

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Intron length distributions and gene prediction

Accurate gene prediction in eukaryotes is a difficult and subtle problem. Here we point out a useful feature of expected distributions of spliceosomal intron lengths. Since introns are removed from transcripts prior to translation, intron lengths are not expected to respect coding frame, thus the number of genomic introns that are a multiple of three bases (‘3n introns’) should be similar to the number that are a multiple of three plus one bases (or plus two bases). Skewed predicted intron length distributions thus suggest systematic errors in intron prediction. For instance, a genome-wide excess of 3n introns suggests that many internal exonic sequences have been incorrectly called introns, whereas a deficit of 3n introns suggests that many 3n introns that lack stop codons have been mistaken for exonic sequence. A survey of genomic annotations for 29 diverse eukaryotic species showed that skew in intron length distributions is a common problem. We discuss several examples of skews in genome-wide intron length distributions that indicate systematic problems with gene prediction. We suggest that evaluation of length distributions of predicted introns is a fast and simple method for detecting a variety of possible systematic biases in gene prediction or even problems with genome assemblies, and discuss ways in which these insights could be incorporated into genome annotation protocols

DISCOVERY OF CHARGE DENSITY PLASMAS IN WATER AND LIVING SYSTEMS

    This paper presents a rigorous examination of Charge Density Plasmas (CDP) and the molecular mechanisms affected by their formation. Charge Density Plasmas have been discovered in both living and non-living systems, including plants, water, people, animals, and soil, although only plants and water are presented in this paper. The properties of COPs are consistent with micro-plasmas that are self-organizing, internally generated, and very sensitive to local and environmental factors. The formation and dissipation of Charge Density Plasmas are related to the formation of molecular clusters and isomer configurations, and can be described using a mathematical model based on an asymptotic time function, as well as perturbation kinetics and reaction rate theory. In experiments with living plants it has been found that COP pulses give evidence for an internal current moving through the plant stem, and each time a CDP pulse forms, an associated magnetic pulse can be simultaneously induced in a nearby probe coil attached to a separate circuit. When a magnet on a pendulum is moved back and forth laterally across the stem, regular periodic oscillations are induced in the microplasma system within the stem. When moved longitudinally or vertically along the stem, these periodic oscillations disappear; again consistent with the plasma model as described by equation (3) in the text. Experiments with distilled water show that CDP pulses propagate in water, and do so differently in the North-South direction than they do in the East-West direction. These pulses appear to travel through one another without interference and thus exhibit the properties of soliton waves. Adding a small amount of ionic salt (KCI at 10 mM) greatly increases the plasma osciJiations and their complexity, which is attributed to cyclotron resonance between the charge density pulses and background ions. CDP diurnal data taken from distilled water 15-20 times per day for several months show distinct differences between the N-S and E-W curves. There is also a common feature in the form of a regular early morning maximum peak amplitude at approximately 7:00 a.m. This COP peak appeared in over 90% of the diurnal data sets and may be the result of the fact that electron density in the atmosphere is more than 100 times greater in the daytime than at night, increasing rapidly at sunrise

Impact of a Professional Development Experience Focused on Extension Educators as Change Agents

Extension educators should think of themselves as change agents, yet many act as information dispensers. Accordingly, we sought to determine whether we could change perceptions of county Extension educators in Oklahoma regarding their function as change agents. Educators participated in a two-part (two-treatment) professional development experience involving a workshop and a computer simulation. The experience was grounded in Rogers\u27s diffusion of innovations theory and addressed nine established Extension educator change-agent roles. Participants ranked the importance of the roles prior to the experience and again following each treatment. Their perceptions changed regarding only the Alternative Delivery Systems role. We explore the imperative to improve Extension agents\u27 understanding of how to be change agents

Prednisolone therapy for chronic hepatitis in English springer spaniels: a prospective study of 12 cases.

BACKGROUND: English springer spaniels (ESS) show an increased risk of chronic hepatitis (CH). In a previous study of 68 ESS with CH, in which only one dog received corticosteroids, a median survival time of 189 days was noted. Some ESS with CH appear to improve with prednisolone treatment; therefore, we aimed to investigate the response to prednisolone in this breed. PARTICIPANTS: ESS with histologically confirmed idiopathic CH were treated with prednisolone 1-2 mg/kg/day. Nine female and three male ESS were enrolled (median age at diagnosis of five years). Patients were monitored clinically and had biochemistry samples taken to assess markers of hepatocellular damage and function. RESULTS: The mean starting dose of prednisolone was 1.1 mg/kg/day. All symptomatic patients showed an initial clinical improvement. Two cases were euthanased while receiving prednisolone. The median time since diagnosis is 1715 days (range: 672-2105 days) and the remaining patients are clinically well, with seven patients still receiving a mean dose of 0.4 mg/kg prednisolone every other day. Statistical analysis demonstrated significant (P<0.05) reductions in serum alkaline phosphatase, alanine aminotransferase and bilirubin following 2-4 weeks of prednisolone treatment. CONCLUSION: This study demonstrates improved clinical and biochemical parameters when some ESS with CH are managed with prednisolone and standard supportive treatments