425 research outputs found

    Does the Settlement Cycle of a Market Predict the Timing of the Turn-of-the-Month Return Reversal? Evidence from Settlement Cycle changes.

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    PURPOSE OF THIS THESIS The purpose of this thesis is to determine if the settlement cycle of a market predicts the timing of the turn-of-the-month return reversal. I use settlement cycle changes in developed countries and study the behaviour of daily average returns around month ends. My main hypotheses are that the turn-of-the-month effect exists in the markets I study, and that the settlement cycle of a market determines the timing of the positive return reversal before month end. DATA AND METHODOLOGY I use benchmark stock index data from developed countries that have had a settlement cycle change during the last three decades. To determine the daily average returns of the turn-of-the-month days during different settlement cycle periods, I run dummy variable regressions. To test the differences in daily average returns during different periods, I run difference-in-means tests. FINDINGS First, I find that more recent the subsample, the weaker the turn-of-the-month effect is in all of the markets I study. In many markets, the turn-of-the-month effect has disappeared completely. I do not find strong evidence to support my hypothesis that the settlement cycle of a market predicts the timing of the turn of the month return reversal. My findings imply that markets are, or have become, more efficient than many studies suggest

    Reactive oxygen species induced structural alterations of substance P

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    Substance P (SP1-11) was exposed to a continuous flux of superoxide ( O 2 - ) or hydroxyl radicals (.OH) in a hypoxanthine (HX)/xanthine oxidase (86 mU) system in the presence of 1 mM deferoxamine and 40 mM D-mannitol or 50 ÎŒM FeCI3. 6H2O and 50 ÎŒM EDTA, respectively. O 2 - caused fragmentation between the Phe7 and Phe8, whereas .OH induced cleavage also between the Phe8 and Gly9. Reactive oxygen species H2O2 and HCIO did not cause fragmentation, but modification of the amino acid side chains and/or aggregation with altered hydrophobicity in reverse phase high performance liquid chromatography compared to native SP1-11. Furthermore, exposure of SP1-11 to phorbol myristate acetate preactivated neutrophils resuited in products similar to those observed upon exposure to superoxide or hydroxyl radicals in a cell-free HX/xanthine oxidase system. This study suggests that, in contrast to rigid proteins, fragmentation is relatively easily induced in a small peptide like SP1-11, perhaps due to strain on the peptide and t-carbon bonds caused by the movable, random coil configuration acquired by SP1-11 in an aqueous solution. Oxidative modification might modulate paracrine actions of SP1-11 at site of inflammation

    A bioactive hybrid three-dimensional tissue-engineering construct for cartilage repair

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    The aim was to develop a hybrid three-dimensional-tissue engineering construct for chondrogenesis. The hypothesis was that they support chondrogenesis. A biodegradable, highly porous polycaprolactone-grate was produced by solid freeform fabrication. The polycaprolactone support was coated with a chitosan/polyethylene oxide nanofibre sheet produced by electrospinning. Transforming growth factor-3-induced chondrogenesis was followed using the following markers: sex determining region Y/-box 9, runt-related transcription factor 2 and collagen II and X in quantitative real-time polymerase chain reaction, histology and immunostaining. A polycaprolactone-grate and an optimized chitosan/polyethylene oxide nanofibre sheet supported cellular aggregation, chondrogenesis and matrix formation. In tissue engineering constructs, the sheets were seeded first with mesenchymal stem cells and then piled up according to the lasagne principle. The advantages of such a construct are (1) the cells do not need to migrate to the tissue engineering construct and therefore pore size and interconnectivity problems are omitted and (2) the cell-tight nanofibre sheet and collagen-fibre network mimic a cell culture platform for mesenchymal stem cells/chondrocytes (preventing escape) and hinders in-growth of fibroblasts and fibrous scarring (preventing capture). This allows time for the slowly progressing, multiphase true cartilage regeneration.Peer reviewe

    Identifying technical, physiological, tactical and psychological characteristics that contribute to career progression in soccer

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    This study sought to examine which technical, physiological, tactical and psychological characteristics at age 15 years contribute to successful soccer performance at age 19 years. Participants were male soccer players (n = 114; mean age 15.4±0.3 years), divided into elite and sub-elite groups based on their performance level at age 19 years. Technical, physiological, tactical and psychological characteristics were recorded when players were 15-year olds. Binary logistic regression analysis showed that performance level at age 19 was clearly associated with technical skills of passing and centering as well as agility and motivation levels recorded at age 15 years. These results extend our understanding of career progression in youth soccer and highlight the multidimensional nature of talent development processes in soccer. Moreover, it seems crucial that coaching support should be devoted to the development of passing and centering skills, agility and motivation in the development of youth players

    Inducible nitric oxide synthase increases secretion from inflamed salivary glands

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    Objective. Salivary gland secretion is dependent on cholinergic stimulation via autonomic nerves and calcium signalling in acinar cells. Secretory dysfunction associated with SS may be partly caused by the damaging effects of increased glandular concentrations of nitric oxide (NO) derived from up-regulation of inducible NO synthase (iNOS) that accompanies glandular inflammation. The present study examines the effects of increased iNOS expression on salivary gland secretory function

    Vertical-external-cavity surface-emitting lasers and quantum dot lasers

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    The use of cavity to manipulate photon emission of quantum dots (QDs) has been opening unprecedented opportunities for realizing quantum functional nanophotonic devices and also quantum information devices. In particular, in the field of semiconductor lasers, QDs were introduced as a superior alternative to quantum wells to suppress the temperature dependence of the threshold current in vertical-external-cavity surface-emitting lasers (VECSELs). In this work, a review of properties and development of semiconductor VECSEL devices and QD laser devices is given. Based on the features of VECSEL devices, the main emphasis is put on the recent development of technological approach on semiconductor QD VECSELs. Then, from the viewpoint of both single QD nanolaser and cavity quantum electrodynamics (QED), a single-QD-cavity system resulting from the strong coupling of QD cavity is presented. A difference of this review from the other existing works on semiconductor VECSEL devices is that we will cover both the fundamental aspects and technological approaches of QD VECSEL devices. And lastly, the presented review here has provided a deep insight into useful guideline for the development of QD VECSEL technology and future quantum functional nanophotonic devices and monolithic photonic integrated circuits (MPhICs).Comment: 21 pages, 4 figures. arXiv admin note: text overlap with arXiv:0904.369
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