Command Interneurons in the Crayfish Central Nervous System

The motor effects evoked by stimulation of each of eight command fibres in the circumoesophageal commissures of the crayfish are described. The fibres obtained appeared to have widespread connexions in all or most of the lower ganglia. For certain fibres the response was stronger on the homolateral side of the animal; for others it was symmetrical. The frequency of stimulation of a command fibre generally had a pronounced influence on the speed of the evoked response. In addition, segments of the total response could be elicited selectively by alteration of the frequency and duration of stimulation. Although the responses associated with most of the fibres were not sensitive to the fine temporal pattern of the applied stimulation, for one fibre the motor output depended clearly on the spacing of the stimulating pulses

Bounds on charged higgs boson in the 2HDM type III from Tevatron

We consider the Two Higgs Doublet Model (2HDM) of type III which leads to Flavour Changing Neutral Currents (FCNC) at tree level. In the framework of this model we can use an appropriate form of the Yukawa Lagrangian that makes the type II model limit of the general type III couplings apparent. This way is useful in order to compare with the experimental data which is model dependent. The analytical expressions of the partial width $\Gamma (t \to H^+ b)$ are derived and we compare with the data available at this energy range. We examine the limits on the new parameters $\lambda_{ij}$ from the validness of perturbation theory.Comment: 14 pages, 4 figures, Universidad Nacional de Colombia. typos correcte

A mixed methods study of a psychoeducational attachment-based intervention for families experiencing separation and loss

This mixed methods study examined foster and adoptive parents’ experience of an attachment-based psychoeducational parent education course. A semi-structured qualitative interview explored parent perceptions of the course content and the impact of the course on parental stress levels, parent-child interactions, and child behavior in a sample of parent participants, after parents completed the 8-week Attachment Security Course. Prior to and following completion of the course parents completed quantitative measures of parenting stress, parent-child interaction, and child behavior. Due to the small sample size, the quantitative results were not interpretable in aggregate form. Emphasis was placed on the qualitative data to gather information about participants’ experience. As the research process progressed a secondary product emerged, a special topics in parenting guide for therapists working from an Attachment Security intervention framework. The results of this study, combined with the literature and clinical experience of providing an Attachment Security course for Veteran parents were used to generate the guide

Remote sensing data as a tool to monitor and mitigate natural catastrophes resulting from anthropogenic activities

This thesis demonstrates how remotely sensed satellite acquisitions can be used to addresses some of the natural catastrophes resulting from anthropogenic activities. Examples from both land and water systems are used to illustrate the breath of this toolbox. The effects of global climate change on biological systems and the wellbeing of everyday people are becoming less easy to ignore. In addition, our oceans are facing multiple large-scale stressors, including microplastics as a recently recognized threat, which place at risk the resources which a large percentage of the world’s population depends on for their livelihood. The cause of many of these changes stem from anthropogenic activities, but lacking understanding of complex ecosystems limits our ability to make definite conclusions as to cause and effect. The difficulty to collect on-the-ground data sufficient enough to capture processes working over scales of hundred of kilometers up to the entire globe is often a limitation to research. Remote sensing systems help ameliorate this issue through providing tools to better monitor environmental changes over large areas. The examples provided in this thesis focus on (Section I) tropical peatland fire characteristics and burning in Southeast Asia as a significant contributor to greenhouse gas emissions and (Section II) spread of river-based plastic pollution in coastal ocean systems. Section I specifically focuses on fires within Indonesia, which holds more than half of all known peatlands in the tropical zone and are estimated to represent a carbon pool of 82–92 gigatons. A brief description of recent development activities within Indonesia is presented in Section I of the Introduction, followed by meteorological processes responsible for extended drought periods in the region, and the situation of current fire control within the country. Chapter 1 presents an example of the large improvement in fire detection, as well as measurement of fire front characteristics, provided by a state-of-the-art thermal remote sensing. Chapter 2 goes into detail describing how an active satellite sensor system is able to provide much quicker and more accurate estimates of burned area for the tropics than other existing methods dependent on passive satellite sensor systems. Both these methods provide powerful tools for development of an improved system to monitor fire over Indonesia. The goal of such a monitoring system would be to reduce fire emissions from this large country, which according to global climate models play an important role in global climate change. Section II focuses on aquatic plastic pollution flowing from a freshwater system into the coastal oceans. A background of the issue of plastic pollution along with the current status of plastic debris in both oceans and inland river systems is presented in Section II of the Introduction. Chapter 3 describes development and comparison of two different modelling efforts to display how plastic particles being emitted from a major river are accumulating along the nearby coastline. The goal of this work is to present how remote sensing data could be used to in conjunction with ocean current modelling to create a comprehensive particle tracking monitoring system.Diese Arbeit zeigt, wie aus der Ferne wahrgenommene Satellitenaufnahmen dazu verwendet werden können, sich einigen Naturkatastrophen, die aus anthropogenen Aktivitäten resultieren, zu widmen. Anhand von Beispielen aus Land- und Wassersystemen wird der Umfang dieses technischen Werkzeugkastens dargestellt. Die Auswirkungen des globalen Klimawandels auf biologische Systeme und das Wohlbefinden des Menschen lassen sich nicht mehr ignorieren. Darüber hinaus sind unsere Ozeane mehreren großen Stressfaktoren ausgesetzt, einschließlich Mikroplastik als eine seit kurzem anerkennte Bedrohung, welche die Ressourcen gefährden, von denen der Lebensunterhalt eines großen Teils der Weltbevölkerung abhängt. Die Ursache vieler dieser Veränderungen liegt in anthropogenen Aktivitäten, aber mangelndes Verständnis für komplexe Ökosysteme begrenzt unsere Fähigkeit, eindeutige Rückschlüsse auf Ursache und Wirkung zu treffen. Die Schwierigkeit, Daten vor Ort zu sammeln, die ausreichen, um Prozesse zu erfassen, die über Hunderte von Kilometern bis hin zum gesamten Globus arbeiten, ist oft eine Einschränkung der Forschung. Fernerkundungssysteme tragen dazu bei, dieses Problem zu beheben, indem sie Werkzeuge zur besseren Überwachung von Umweltveränderungen in großen Gebieten bereitstellen. Die Beispiele in dieser Arbeit konzentrieren sich auf („Section I“) Feuermerkmale und Brandflächen der tropischen Torfgebiete in Südostasien als signifikanter Beitrag zu Treibhausgasemissionen und („Section II“) Ausbreitung von Fluss-basiertem Plastikmüll in küstennahen Meeressystemen. Section I konzentriert sich speziell auf die Brände in Indonesien, welches mehr als die Hälfte aller bekannten Torfgebiete in der tropischen Zone besitzt und auf einen Kohlenstoffpool von 82-92 Gigatonnen geschätzt wird. Eine kurze Beschreibung der jüngsten Entwicklungstätigkeiten in Indonesien wird in Section I der Einleitung vorgestellt, gefolgt von meteorologischen Prozessen, die für ausgedehnte Dürreperioden in der Region verantwortlich sind, und der Situation der aktuellen Feuerkontrolle innerhalb des Landes. Chapter 1 zeigt ein Beispiel für die große Verbesserung der Branddetektion sowie die Messung der Brandfronteigenschaften, die durch eine moderne thermische Fernerkundung erreicht werden können. In Chapter 2 wird ausführlich beschrieben, wie ein aktives Satellitensensorsystem in der Lage ist, schnellere und genauere Schätzungen der verbrannten Fläche für die Tropen zu liefern als andere existierende Methoden, die von passiven Satellitensensorsystemen abhängen. Beide Methoden bieten leistungsstarke Werkzeuge für die Entwicklung eines verbesserten Systems zur Brandüberwachung von Indonesien. Ziel eines solchen Überwachungssystems wäre es, Brandemissionen aus diesem großen Land zu reduzieren, das nach globalen Klimamodellen eine wichtige Rolle im globalen Klimawandel spielt. Section II konzentriert sich auf die Verschmutzung von Wasserplastik, die von einem Süßwassersystem in die Küstenmeere fließt. Ein Hintergrund des Problems der Plastikverschmutzung zusammen mit dem gegenwärtigen Status von Plastiktrümmern sowohl in Ozeanen als auch Binnenflusssystemen wird in Section II der Einleitung dargestellt. Chapter 3 beschreibt die Entwicklung und den Vergleich von zwei verschiedenen Modellierungsbemühungen, um zu zeigen, wie sich Kunststoffpartikel, die von einem großen Fluss emittiert werden, entlang der nahen Küstenlinie ansammeln. Das Ziel dieser Arbeit ist zu zeigen, wie Fernerkundungsdaten in Verbindung mit Meeresströmungsmodellierung verwendet werden können, um ein umfassendes Teilchenverfolgungsüberwachungssystem zu schaffen

Implications for B→ηKB \to \eta K and B→Glueball+KB \to Glueball + K Modes from Observed Large B→η′K+XB\to \eta' K+X

The unexpectedly large branching ratios for $B\to \eta' K (\eta' X_s)$ decays could be of gluonic origin. We study the implications for $B\to \eta K (\eta X_s)$ and $P K (PX_s)$, where $P$ is the pseudoscalar glueball. In the mechanism proposed by Fritzsch, large branching ratios are predicted for these modes. The $B\to \eta K$ rate is barely within the experimental limit, and $B\to P K$, $PX_s$ could be at the 0.1% and 1% level, respectively. Smaller but less definite results are found for the mechanism of $g^* \to \eta' g$ via the gluon anomaly.Comment: 11 pages, revtex, no fig

CP Nonconservation in ppˉ→tbˉXp\bar p\to t\bar b X at the Tevatron

The reaction $p\bar p\to t\bar bX$ is found to be rather rich in exhibiting several different types of CP asymmetries. The spin of the top quark plays an important role. Asymmetries are related to form factors arising from radiative corrections of the $tbW$ production vertex due to non-standard physics. As illustrations, effects are studied in two Higgs Doublet Models and in Supersymmetric Models; asymmetries up to a few percent may be possible.Comment: 14 pages, 3 figures. Note: replaced due to minor problems that appeared on some postscript previewers. No change in conten

Navier-Stokes simulations of unsteady transonic flow phenomena

Numerical simulations of two classes of unsteady flows are obtained via the Navier-Stokes equations: a blast-wave/target interaction problem class and a transonic cavity flow problem class. The method developed for the viscous blast-wave/target interaction problem assumes a laminar, perfect gas implemented in a structured finite-volume framework. The approximately factored implicit scheme uses Newton subiterations to obtain the spatially and temporally second-order accurate time history of the blast-waves with stationary targets. The inviscid flux is evaluated using either of two upwind techniques, while the full viscous terms are computed by central differencing. Comparisons of unsteady numerical, analytical, and experimental results are made in two- and three-dimensions for Couette flows, a starting shock-tunnel, and a shock-tube blockage study. The results show accurate wave speed resolution and nonoscillatory discontinuity capturing of the predominantly inviscid flows. Viscous effects were increasingly significant at large post-interaction times. While the blast-wave/target interaction problem benefits from high-resolution methods applied to the Euler terms, the transonic cavity flow problem requires the use of an efficient scheme implemented in a geometrically flexible overset mesh environment. Hence, the Reynolds averaged Navier-Stokes equations implemented in a diagonal form are applied to the cavity flow class of problems. Comparisons between numerical and experimental results are made in two-dimensions for free shear layers and both rectangular and quieted cavities, and in three-dimensions for Stratospheric Observatory For Infrared Astronomy (SOFIA) geometries. The acoustic behavior of the rectangular and three-dimensional cavity flows compare well with experiment in terms of frequency, magnitude, and quieting trends. However, there is a more rapid decrease in computed acoustic energy with frequency than observed experimentally owing to numerical dissipation. In addition, optical phase distortion due to the time-varying density field is modelled using geometrical constructs. The computed optical distortion trends compare with the experimentally inferred result, but underpredicts the fluctuating phase difference magnitude