1,084 research outputs found
The Regulation of Insider Trading in Germany: Who\u27s Afraid of Self-Restraint
From near total destruction forty-one years ago, the Federal Republic of Germany has emerged as the fourth wealthiest industrialized nation. Yet despite this wealth, the German capital markets remain miniscule in comparison to those of other industrialized nations. This development has had a significantly adverse effect on the ability of German companies to raise equity capital. The aversion of individual Germans to invest in equity securities can be explained on a number of levels. First, many investors find that fixed-rate bonds and similar securities provide equal if not better yields than stocks, without the concomitant risk. Another significant reason that many small investors in Germany shy away from stock investments is the widely-held belief that the markets are, to some extent, fixed; in particular, that insiders and speculators retain a significant advantage over the common investor. The purpose of this Article is to explore the German approach to the regulation of insider trading
Hidden variables unseen by Random Forests
Random Forests are widely claimed to capture interactions well. However, some
simple examples suggest that they perform poorly in the presence of certain
pure interactions that the conventional CART criterion struggles to capture
during tree construction. We argue that alternative partitioning schemes can
enhance identification of these interactions. Furthermore, we extend recent
theory of Random Forests based on the notion of impurity decrease by
considering probabilistic impurity decrease conditions. Within this framework,
consistency of a new algorithm coined 'Random Split Random Forest' tailored to
address function classes involving pure interactions is established. In a
simulation study, we validate that the modifications considered enhance the
model's fitting ability in scenarios where pure interactions play a crucial
role
In-hospital safety in field conditions of Nifurtimox Eflornithine Combination Therapy (NECT) for T. B. Gambiense Sleeping Sickness
Trypanosoma brucei (T.b.) gambiense Human African trypanosomiasis (HAT; sleeping sickness) is a fatal disease. Until 2009, available treatments for 2(nd) stage HAT were complicated to use, expensive (eflornithine monotherapy), or toxic, and insufficiently effective in certain areas (melarsoprol). Recently, nifurtimox-eflornithine combination therapy (NECT) demonstrated good safety and efficacy in a randomised controlled trial (RCT) and was added to the World Health Organisation (WHO) essential medicines list (EML). Documentation of its safety profile in field conditions will support its wider use
Water adsorption on vanadium oxide thin films in ambient relative humidity.
In this work, ambient pressure x-ray photoelectron spectroscopy (APXPS) is used to study the initial stages of water adsorption on vanadium oxide surfaces. V 2p, O 1s, C 1s, and valence band XPS spectra were collected as a function of relative humidity in a series of isotherm and isobar experiments. Experiments were carried out on two VO2 thin films on TiO2 (100) substrates, prepared with different surface cleaning procedures. Hydroxyl and molecular water surface species were identified, with up to 0.5 ML hydroxide present at the minimum relative humidity, and a consistent molecular water adsorption onset occurring around 0.01% relative humidity. The work function was found to increase with increasing relative humidity, suggesting that surface water and hydroxyl species are oriented with the hydrogen atoms directed away from the surface. Changes in the valence band were also observed as a function of relative humidity. The results were similar to those observed in APXPS experiments on other transition metal oxide surfaces, suggesting that H2O-OH and H2O-H2O surface complex formation plays an important role in the oxide wetting process and water dissociation. Compared to polycrystalline vanadium metal, these vanadium oxide films generate less hydroxide and appear to be more favorable for molecular water adsorption
A mathematical model for LH release in response to continuous and pulsatile exposure of gonadotrophs to GnRH
In a previous study, a model was developed to investigate the release of luteinizing hormone (LH) from pituitary cells in response to a short pulse of gonadotropin-releasing hormone (GnRH). The model included: binding of GnRH to its receptor (R), dimerization and internalization of the hormone receptor complex, interaction with a G protein, production of inositol 1,4,5-trisphosphate (IP(3)), release of calcium from the endoplasmic reticulum (ER), entrance of calcium into the cytosol via voltage gated membrane channels, pumping of calcium out of the cytosol via membrane and ER pumps, and release of LH. The extended model, presented in this paper, also includes the following physiologically important phenomena: desensitization of calcium channels; internalization of the dimerized receptors and recycling of some of the internalized receptors; an increase in G(q )concentration near the plasma membrane in response to receptor dimerization; and basal rates of synthesis and degradation of the receptors. With suitable choices of the parameters, good agreement with a variety of experimental data of the LH release pattern in response to pulses of various durations, repetition rates, and concentrations of GnRH were obtained. The mathematical model allows us to assess the effects of internalization and desensitization on the shapes and time courses of LH response curves
Multivariate sensor signals collected by aquatic drones involved in water monitoring: A complete dataset
Sensor data generated by intelligent systems, such as autonomous robots, smart buildings and other systems based on artificial intelligence, represent valuable sources of knowledge in today\u2019s data-driven society, since they contain information about the situations these systems face during their operation. These data are usually multivariate time series since modern technologies enable the simultaneous acquisition of multiple signals during long periods of time. In this paper we present a dataset containing sensor traces of six data acquisition campaigns performed by autonomous aquatic drones involved in water monitoring. A total of 5.6 hours of navigation are available, with data coming from both lakes and rivers, and from different locations in Italy and Spain. The monitored variables concern both the internal state of the drone (e.g., battery voltage, GPS position and signals to propellers) and the state of the water (e.g., temperature, dissolved oxygen and electrical conductivity). Data were collected in the context of the EU-funded Horizon 2020 project INTCATCH (http://www.intcatch.eu) which aims to develop a new paradigm for monitoring water quality of catchments. The aquatic drones used for data acquisition are Platypus Lutra boats. Both autonomous and manual drive is used in different parts of the navigation. The dataset is analyzed in the paper \u201cTime series segmentation for state-model generation of autonomous aquatic drones: A systematic framework\u201d [1] by means of recent time series clustering/segmentation techniques to extract data-driven models of the situations faced by the drones in the data acquisition campaigns. These data have strong potential for reuse in other kinds of data analysis and evaluation of machine learning methods on real-world datasets [2]. Moreover, we consider this dataset valuable also for the variety of situations faced by the drone, from which machine learning techniques can learn behavioural patterns or detect anomalous activities. We also provide manual labeling for some known states of the drones, such as, drone inside/outside the water, upstream/downstream navigation, manual/autonomous drive, and drone turning, that represent a ground truth for validation purposes. Finally, the real-world nature of the dataset makes it more challenging for machine learning methods because it contains noisy samples collected while the drone was exposed to atmospheric agents and uncertain water flow conditions
The Relation of Lime and Phosphoric Acid to the Growth and Bone Development of White Rats.
18 p
Theory of Second Order Optical Processes from A Luttinger Liquid
We develop a theory for the total optical secondary emission from a 1D
interacting electron system modelled as a Tomonaga-Luttinger liquid. We
separate the emission into two parts which may originate in {\em hot
luminescence} (HL) and {\em Raman Scattering} (RS) respectively when we neglect
the {\em interference} effect. We find a peak around
in the RS part which does not come from a structure factor peak. In general the
total emission cannot be separated into HL and RS. However at resonance, and
taking into account the dependence of the optical matrix element, a part of
the RS is proportional to the structure factor .Comment: 13 pages (REVTEX 3.0), CCNY-CMT-94-901, (to be published in Solid
State Communication
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