Extensions of rich words

In [X. Droubay et al, Episturmian words and some constructions of de Luca and Rauzy, Theoret. Comput. Sci. 255 (2001)], it was proved that every word w has at most |w|+1 many distinct palindromic factors, including the empty word. The unified study of words which achieve this limit was initiated in [A. Glen et al, Palindromic richness, Eur. Jour. of Comb. 30 (2009)]. They called these words rich (in palindromes). This article contains several results about rich words and especially extending them. We say that a rich word w can be extended richly with a word u if wu is rich. Some notions are also made about the infinite defect of a word, the number of rich words of length n and two-dimensional rich words.Comment: 19 pages, 3 figure

Conditional BVARX Forecasting Model for Small Open Economies : An Application to Finland

In this thesis, a conditional BVARX forecasting model for short and medium term economic forecasting is developed. The model is especially designed for small-open economies and its performance on forecasting several Finnish economic variables is assessed. Particular attention is directed to the hyperparameter choice of the model. A novel algorithm for hyperparameter choice is proposed and it is shown to outperform the marginal likelihood based approach often encountered in the literature. Other prominent features of the model include conditioning on predictive densities and exogeneity of the global economic variables. The model is shown to outperform univariate benchmark models in terms of forecasting accuracy for forecasting horizons up to eight quarters ahead.Tässä tutkielmassa kehitetään BVARX-ennustemalli lyhyen ja keskipitkän aikavälin taloudelliseen ennustamiseen. Malli on erityisesti kehitetty pienten avotalouksien erityispiirteet huomioon ottaen ja tutkielmassa testataan mallin kykyä ennustaa useita suomalaisia taloudellisia muuttujia. Erityistä huomiota tutkielmassa kiinnitetään mallin hyperparametrien valintaan. Tutkielmassa esitellään uusi menetelmä hyperparametrien valitsemiseksi ja uuden menetelmän näytetään tuottavan tarkempia ennusteita kuin kirjallisuudessa usein käytetty marginal likelihood funktioon perustuva lähestymistapa. Muita mallin erityispiirteitä ovat mahdollisuus ehdollistaa ennusteita mallin muuttujien tulevilla arvoilla tai tiheyksillä ja globaalien taloudellisten muuttujien eksogeenisuus. Tutkielmassa kehitetyn ennustemallin näytetään tuottavan tarkempia ennusteita kuin vertailukohtana käytettävät yhden muuttujan menetelmät kaikilla tarkastelluilla ennustehorisonteilla yhdestä kahdeksaan neljännestä tulevaisuuteen

Effects of Obesity and Weight Loss Following Bariatric Surgery on Brain Function, Structural Integrity and Metabolism

Obesity is one of the key challenges to health care system worldwide and its prevalence is estimated to rise to pandemic proportions. Numerous adverse health effects follow with increasing body weight, including increased risk of hypertension, diabetes, hypercholesterolemia, musculoskeletal pain and cancer. Current evidence suggests that obesity is associated with altered cerebral reward circuit functioning and decreased inhibitory control over appetitive food cues. Furthermore, obesity causes adverse shifts in metabolism and loss of structural integrity within the brain. Prior cross-sectional studies do not allow delineating which of these cerebral changes are recoverable after weight loss. We compared morbidly obese subjects with healthy controls to unravel brain changes associated with obesity. Bariatric surgery was used as an intervention to study which cerebral changes are recoverable after weight loss. In Study I we employed functional magnetic resonance imaging (fMRI) to detect the brain basis of volitional appetite control and its alterations in obesity. In Studies II-III we used diffusion tensor imaging (DTI) and voxel-based morphometry (VBM) to quantify the effects of obesity and the effects of weight loss on structural integrity of the brain. In study IV we used positron emission tomography (PET) with [18F]-FDG in fasting state and during euglycemic hyperinsulinemia to quantify effects of obesity and weight loss on brain glucose uptake. The fMRI experiment revealed that a fronto-parietal network is involved in volitional appetite control. Obese subjects had lower medial frontal and dorsal striatal brain activity during cognitive appetite control and increased functional connectivity within the appetite control circuit. Obese subjects had initially lower grey matter and white matter densities than healthy controls in VBM analysis and loss of integrity in white matter tracts as measured by DTI. They also had initially elevated glucose metabolism under insulin stimulation but not in fasting state. After the weight loss following bariatric surgery, obese individuals’ brain volumes recovered and the insulin-induced increase in glucose metabolism was attenuated. In conclusion, obesity is associated with altered brain function, coupled with loss of structural integrity and elevated glucose metabolism, which are likely signs of adverse health effects to the brain. These changes are reversed by weight loss after bariatric surgery, implicating that weight loss has a causal role on these adverse cerebral changes. Altogether these findings suggest that weight loss also promotes brain health.Key words: brain, obesity, bariatric surgery, appetite control, structural magnetic resonanceLihavuus yleistyy nopeasti koko maailmassa ja se on yksi suurimmista terveydenhuollon tulevaisuuden haasteista. Lihavuus lisää riskiä sairastua useisiin sairauksiin mm. verenpainetautiin, diabetekseen, tuki- ja liikuntaelinten sairauksiin ja useisiin syöpiin. Lihavilla on havaittu aivojen palkkiojärjestelmän reagoivan yliaktiivisesti ruokaan liittyviin ärsykkeisiin ja toisaalta ruokahalua hillitsevien alueiden toiminnan on havaittu olevan heikompaa kuin normaalipainoisilla. Lihavuus aiheuttaa myös haitallisia muutoksia aivosolujen rakenteessa ja aineenvaihdunnassa. Näiden muutosten palautumispotentiaalia ei voida arvioida poikkileikkaustutkimuksissa. Tässä työssä tutkimme sairaalloisen lihavia lihavuusleikkaukseen valittuja potilaita, joiden aivokuvantamistuloksia verrattiin normaalipainoisten vastaaviin kuvauksiin. Potilaat tutkittiin myös kuusi kuukautta lihavuusleikkauksen jälkeen painonlaskun aiheuttamien aivomuutosten tutkimiseksi. Ensimmäisessä tutkimuksessa ruokahalun säätelyjärjestelmän toiminnan ja lihavuuden aiheuttamien muutosten selvittämiseksi käytettiin toiminnallista magneettikuvantamista (fMRI). Rakenteellisia muutoksia arvioitiin II ja III osatyössä diffuusiotensorikuvantamisella (DTI) sekä vokseliperustaisen morfometrian avulla (VBM). Neljännessä osatyössä aivojen sokeriaineenvaihduntaa tutkittiin positroniemissiotomografian (PET) avulla käyttämällä [18F]-FDG-merkkiainetta paastotilassa ja insuliini-stimulaation aikana. VBM -ja PET-menetelmiä käytettiin myös lihavuusl eikkauksen vaikutusten arviointiin. fMRI-kokeessa havaittiin, että ruokahalun säätelyyn osallistuu laaja hermoverkko jonka keskeiset osat sijoittuvat otsa- ja päälaenlohkoihin. Lihavilla tutkittavilla havaittiin alentuneet vasteet häntätumakkeessa ja etupihtipoimun alueella. Lisäksi heillä havaittiin voimakkaammat toiminnalliset yhteydet ruokahalun säätelyverkostossa. Lihavuus aiheuttaa aivoissa laajaa aivokudoksen harventumaa ja hermoratojen eheyden alentumaa. PET-tutkimuksessa havaittiin lihavuuden lisäävän aivojen insuliiniherkkyyttä. Puoli vuotta lihavuusleikkauksen jälkeen rakenteelliset ja aineenvaihdunnan muutokset palautuivat osittain.Siirretty Doriast

Effects of 2-chloroethylphosphonic acid formulations as yield stimulants on Hevea brasiliensis

Stimulation of Hevea brasiliensis is a common practice in rubber estates. The chemicals commonly used are formulations of 2-chloroethylphosphonic acid (ethephon). Low frequency of tapping must be accompanied by use of yield stimulants in order to enjoy the economics of low tapping frequency. It is thus necessary to evaluate the effects of the available yield stimulants on Hevea in order to betterformulate exploitation systems. Two formulations of  2-chloroethylphosphonic acid, under the tradename Hevetex 5% PA and Ehtrel® were used to stimulate two clones. Hevetex 5% PA was investigated using agronomic parameters, and latex diagnosis technique to determine its efficiency as a yieldstimulant, its ability to induce tree dryness, activation of tree metabolism and ability to sustain rubber yields. Hevetex 5% PA is a good yield stimulant and has good sustaining properties demonstrated by the level of its physiological properties (such as sugar and thiols) which are comparable to those of Ethrel®. The use of these stimulants led to an increase in rubber yield. The physiological parametersand yield varied with season

On Kaluza’s sign criterion for reciprocal power series

T. Kaluza has given a criterion for the signs of the power series of a function that is the reciprocal of another power series. In this note the sharpness of this condition is explored and various examples in terms of the Gaussian hypergeometric series are given. A criterion for the monotonicity of the quotient of two power series due to M. Biernacki and J. Krzyż is applied

Spaceports: Portals to the Universe

A review of online learning resources for children, parents, and teachers reveal instructions and learning tools for a wide range of topics including rockets, spacecraft, satellites, planetary and lunar land vehicles; propulsion systems; planets, moons, and solar systems; spacesuits, among others. Yet, no resources were found on the topic of spaceports (spaceport infrastructure, operations, management, business of space ) needed to support the safe and efficient integration, launch, and return of vehicles, crew, and payloads Surveys, experiments, and secondary data analysis were then used to identify topic interests for an educational curriculum to be developed on spaceports for a targeted segment of the population. Results gathered help to create materials, lesson plans, and knowledge for a “ready to go” curriculum that can be provided to a summer camp environment. The completion of this investigation will allow children to have a better understanding of the relationship between spaceports and the community, as currently there are little to no resources available to learn more about them. It will also demonstrate that space is a place for everyone, with many work opportunities outside of being an astronaut or engineer