The perception of touch and the ventral somatosensory pathway.

In humans, touching the skin is known to activate, among others, the contralateral primary somatosensory cortex on the postcentral gyrus together with the bilateral parietal operculum (i.e. the anatomical site of the secondary somatosensory cortex). But which brain regions beyond the postcentral gyrus specifically contribute to the perception of touch remains speculative. In this study we collected structural magnetic resonance imaging scans and neurological examination reports of patients with brain injuries or stroke in the left or right hemisphere, but not in the postcentral gyrus as the entry site of cortical somatosensory processing. Using voxel-based lesion-symptom mapping, we compared patients with impaired touch perception (i.e. hypoaesthesia) to patients without such touch impairments. Patients with hypoaesthesia as compared to control patients differed in one single brain cluster comprising the contralateral parietal operculum together with the anterior and posterior insular cortex, the putamen, as well as subcortical white matter connections reaching ventrally towards prefrontal structures. This finding confirms previous speculations on the 'ventral pathway of somatosensory perception' and causally links these brain structures to the perception of touch.

Speculation, risk premia and expectations in the yield curve

An affine asset pricing model in which traders have rational but heterogeneous expectations aboutfuture asset prices is developed. We use the framework to analyze the term structure of interestrates and to perform a novel three-way decomposition of bond yields into (i) average expectationsabout short rates (ii) common risk premia and (iii) a speculative component due to heterogeneousexpectations about the resale value of a bond. The speculative term is orthogonal to public informationin real time and therefore statistically distinct from common risk premia. Empirically wefind that the speculative component is quantitatively important accounting for up to a percentagepoint of yields, even in the low yield environment of the last decade. Furthermore, allowing for aspeculative component in bond yields results in estimates of historical risk premia that are morevolatile than suggested by standard Affine Gaussian term structure models which our frameworknests.

Comprendre les mécanismes des migrations « glo-balles » africaines. Les trajectoires transnationales et la diversification des filières

L'article décrypte certains rouages de l'expatriation des joueurs africains vers l'Europe. La précocité de leur migration et la fragmentation de leur trajectoire sont expliquées par les spéculations dont ils font l'objet. Les réseaux socio-économiques qui portent les filières spéculatives sont mis en lumière, ce qui permet de comprendre en particulier le rôle primordial qu'y jouent les clubs intermédiaires européens, et maintenant asiatiques, intermédiaires dans la chaîne à haute valeur ajoutée, au « taux d'éviction » le plus élevé du monde. This paper decodes various workings at play in the expatriation of African players to Europe. The early nature of their migration and the fragmentation of their trajectories are explained by the speculation that surrounds them. The socio-economic networks that carry speculative channels are brought to light, which helps us to understand in particular the major role played by the European, and now Asian, clubs, which serve as intermediaries in the high value-added chain, with the highest "eviction rate" in the world.

Tracking the invisible hand: Convergence of double auctions to competitive equilibrium

Economics is the science of want and scarcity. We show that want andscarcity, operating within a simple exchange institution (double auction),are sufficient for an economy consisting of multiple inter--related marketsto attain competitive equilibrium (CE). We generalize Gode and Sunder's(1993a, 1993b) single--market finding to multi--market economies, andexplore the role of the scarcity constraint in convergence of economies to CE.When the scarcity constraint is relaxed by allowing arbitrageurs in multiple markets to enter speculative trades, prices still converge to CE,but allocative efficiency of the economy drops. \\Optimization by individual agents, often used to derive competitive equilibria,are unnecessary for an actual economy to approximately attain such equilibria.From the failure of humans to optimize in complex tasks, one need not concludethat the equilibria derived from the competitive model are descriptivelyirrelevant. We show that even in complex economic systems, such equilibriacan be attained under a range of surprisingly weak assumptions about agentbehavior.

On ignoring scientific evidence: The bumpy road to enlightenment

It is well accepted that people resist evidence that contradicts their beliefs.Moreover, despite their training, many scientists reject results that are inconsistent withtheir theories. This phenomenon is discussed in relation to the field of judgment anddecision making by describing four case studies. These concern findings that clinical judgment is less predictive than actuarial models; simple methods have proven superiorto more theoretically correct methods in times series forecasting; equal weighting ofvariables is often more accurate than using differential weights; and decisions cansometimes be improved by discarding relevant information. All findings relate to theapparently difficult-to-accept idea that simple models can predict complex phenomenabetter than complex ones. It is true that there is a scientific market place for ideas.However, like its economic counterpart, it is subject to inefficiencies (e.g., thinness,asymmetric information, and speculative bubbles). Unfortunately, the market is only correct in the long-run. The road to enlightenment is bumpy.

Transformation of a microprolactinoma into a mixed growth hormone and prolactin-secreting pituitary adenoma.

Combined prolactin (PRL) and growth hormone (GH) secretion by a single pituitary tumor can occur in approximately 5% of cases. However, in all previously reported patients, combined secretion of both hormones was present at the time of diagnosis. Here we describe a patient initially diagnosed with a pure prolactin-secreting microadenoma, who experienced the progressive apparition of symptomatic autonomous GH secretion while on intermittent long term dopamine agonist therapy. She was operated on, and immunohistochemical analysis of tumor tissue confirmed the diagnosis of pituitary adenoma with uniform co-staining of all cells for both GH and PRL. This patient represents the first documented occurrence of asynchronous development of combined GH and PRL secretion in a pituitary adenoma. Although pathogenic mechanisms implicated remain largely speculative, it emphasizes the need for long term hormonal follow up of patients harboring prolactinomas.

The Soja and Luzzone-Terri nappes: discovery of a Briançonnais element below the front of the Adula nappe (NE Ticino, Central Alps)

The classical Soja nappe, in NE Ticino, actually consists of two distinct tectonic units with verydifferent stratigraphic contents: (1) The smaller one, in the Val Soi (the type-locality), is by definitionthe Soja unit s.str.. It is pinched between Simano and Adula and consists of various Paleozoic gneissesand a dolomitic Triassic cover analogous to the Triassic of other Lower Penninic nappes. (2) The largerone extends along the Lago di Luzzone and continues eastwards through the Piz Terri mountain. Wename it the Luzzone-Terri nappe. It consists of: (a) a paragneiss series that presents striking similaritieswith the Permian of the Zone Houillère in Valais; (b) a Triassic cover typical of the Briançonnaisdomain where one clearly recognizes the St-Triphon Formation and other characteristic units of theBriançonnais Triassic; (c) a thick series of black calcschists and metapelites of Liassic age, similarto the cover of the neighbouring Gotthard massif. This stratigraphic superposition of a Liassic seriesof Helvetic type on a Briançonnais Triassic is unique in the Alps and has important paleogeographicconsequences. It is difficult to reconcile this observation with speculative reconstructions that proposean original position of the Briançonnais domain far from the Helvetic basins. Morover the Briançonnaischaracter of its Triassic series indicates an ultra-Adula origin of the Luzzone-Terri nappe.

Media, investors and bubbles

We analysed the specific case of how information in the financial press influences economic bubbles. We found considerable flaws in the information market due to several factors: demand, the predominance of what are termed “irrational investors” (herding), and supply, which has the problem that the sources of information are biasedand feeds. A financial bubble is a deviation between real value of a financial asset and its persistent market price in time, which also has a speculative origin fed back by the illusion of the owners of these financial values, who will take benefits because of the future prices, which must be higher than the previous ones. The economical information in the media is submitting three problems. First of all, it is information generated by companies. In second place, the information circuit is fed back. A problem of informative independence becomes created, particularly serious in the case of the banks, which are very were as creditors. And in a third place, some informative biases are manifested for the companies of regulated sectors which are starring the economical information in the media.

Structure of the ovaries of the Nimba otter shrew, Micropotamogale lamottei, and the Madagascar hedgehog tenrec, Echinops telfairi.

The otter shrews are members of the subfamily Potamogalinae within the family Tenrecidae. No description of the ovaries of any member of this subfamily has been published previously. The lesser hedgehog tenrec, Echinops telfairi, is a member of the subfamily Tenrecinae of the same family and, although its ovaries have not been described, other members of this subfamily have been shown to have ovaries with non-antral follicles. Examination of these two species illustrated that non-antral follicles were characteristic of the ovaries of both species, as was clefting and lobulation of the ovaries. Juvenile otter shrews range from those with only small follicles in the cortex to those with 300- to 400-microm follicles similar to those seen in non-pregnant and pregnant adults. As in other species, most of the growth of the oocyte occurred when follicles had one to two layers of granulosa cells. When larger follicles became atretic in the Nimba otter shrew, hypertrophy of the theca interna produced nodules of glandular interstitial tissue. In the tenrec, the hypertrophying theca interna cells in most large follicles appeared to undergo degeneration. Both species had some follicular fluid in the intercellular spaces between the more peripheral granulosa cells. It is suggested that this fluid could aid in separation of the cumulus from the remaining granulosa at ovulation. The protruding follicles in lobules and absence of a tunica albuginea might also facilitate ovulation of non-antral follicles. Ovaries with a thin-absent tunica albuginea and follicles with small-absent antra are widespread within both the Eulipotyphla and in the Afrosoricida, suggesting that such features may represent a primitive condition in ovarian development. Lobulated and deeply crypted ovaries are found in both groups but are not as common in the Eulipotyphla making inclusion of this feature as primitive more speculative.

Laivan ilmastointijärjestelmän perussuunnittelu ja mitoitus

Diplomityön tavoitteena on tarkastella risteilyaluksen ilmastointijärjestelmän suunnittelua ilmamäärien mitoituksen kannalta esisuunnitteluvaiheessa ja lopullisia laskelmia tehtäessä. Teoriaosassa tutustutaan hyvän sisäilmaston tekijöihin ja tarkastellaan ilmankäsittelyä laivoissa yleensä. Tilakohtaisia mitoituksia varten työssä esitellään perusteita, joita suunnittelijan on tunnettava ja huomioitava. Työn tuloksena esitellään laskentaohjelma, joka luo pohjaa tarkempaan ilmamäärälaskentaan standardin ISO 7547 mukaisesti. Ohjelman avulla ilmastoitavaan tilaan saadaan raitisilmamäärään, ilmanvaihtokertoimeen tai lämpökuormiin perustuva ilmamäärä. Esisuunnitteluvaiheessa alustavia ilmamäärälaskelmia tarvitaan tilavarausten riittävyyden tarkasteluun sekä tarjouskeskustelujen aloittamiseen toimittajien kanssa. Ilmamäärän arviointi perustuu vertailulaivoista määritettyihin eri tilatyyppien ja tilojen keskimääräisiin ilmanvaihtokertoimiin. Tilatyyppeihin perustuvilla kertoimilla saadaan tietokoneen avulla nopeasti karkea kuva ilmamäärien suuruusluokasta, tilabudjetin nimityksiin perustuvalla menetelmällä saadaan tarkempia arvioita ilmamääristä.

OKO:n luottoriskiluokitus: tunnuslukumallin kehittäminen suomalaisyritysten arviointiin

Pro gradu -tutkielma keskittyy OKO:n yritysasiakkaiden luottoriskiluokituksessa käyttämään tunnuslukumalliin. Tutkielman tavoitteena on tutkia, miten suomalaisyritysaineistosta johdettu tunnuslukumalli luokittelee yrityksiä eri tavalla OKO:n nykyiseen malliin verrattuna. Tutkielma rakentuu kirjallisuuteen perustuvasta teoreettisesta viitekehyksestä sekä varsinaisesta empiirisestä tutkimuksesta. Tutkimuksessa käytetään kvantitatiivisia tutkimusmetodeja, joissa aineiston tarkastelun avulla pyritään tekemään järkeistettyjä päätöksiä. Tutkimusaineisto koostuu 4889 tilinpäätöksestä vuosilta 1991-2001, jotka on saatu Etlan 500 suurimman suomalaisyrityksen tilinpäätöstietokannasta. Tutkimuksessa tarkastellaan suomalaisyritysten tunnuslukujen jakautumista viidellä toimialalla sekä kahdessa ajanjaksossa. Toimialakohtaisista tunnuslukujakaumista johdetaan uuden mallin tunnuslukukohtaiset luokkarajat. Uusien luokkarajojen voidaan todeta olevan tunnusluvusta riippuen joko korkeammat tai matalammat kuin nykyisen yhdysvaltalaisaineistoon pohjautuvan tunnuslukumallin luokkarajat. Uuden ja nykyisen tunnuslukumallin antamia luokituksia verrataan 51 case-yrityksen avulla. Tutkimus osoittaa, että uusi tunnuslukumalli luokittelee yrityksiä pääasiassa parempiin tai samoihin luottoriskiluokkiin kuin nykyinen malli. Luokitusmuutoksia esiintyy useammin spekulatiivisen tason yrityksillä kuin investointitason yrityksillä

E-Cigarettes: A Review of New Trends in Cannabis Use.

The emergence of electronic cigarettes (e-cigs) has given cannabis smokers a new method of inhaling cannabinoids. E-cigs differ from traditional marijuana cigarettes in several respects. First, it is assumed that vaporizing cannabinoids at lower temperatures is safer because it produces smaller amounts of toxic substances than the hot combustion of a marijuana cigarette. Recreational cannabis users can discretely "vape" deodorized cannabis extracts with minimal annoyance to the people around them and less chance of detection. There are nevertheless several drawbacks worth mentioning: although manufacturing commercial (or homemade) cannabinoid-enriched electronic liquids (e-liquids) requires lengthy, complex processing, some are readily on the Internet despite their lack of quality control, expiry date, and conditions of preservation and, above all, any toxicological and clinical assessment. Besides these safety problems, the regulatory situation surrounding e-liquids is often unclear. More simply ground cannabis flowering heads or concentrated, oily THC extracts (such as butane honey oil or BHO) can be vaped in specially designed, pen-sized marijuana vaporizers. Analysis of a commercial e-liquid rich in cannabidiol showed that it contained a smaller dose of active ingredient than advertised; testing our laboratory-made, purified BHO, however, confirmed that it could be vaped in an e-cig to deliver a psychoactive dose of THC. The health consequences specific to vaping these cannabis preparations remain largely unknown and speculative due to the absence of comprehensive, robust scientific studies. The most significant health concerns involve the vaping of cannabinoids by children and teenagers. E-cigs could provide an alternative gateway to cannabis use for young people. Furthermore, vaping cannabinoids could lead to environmental and passive contamination.

Chlamydiaceae and Chlamydia-like organisms in the koala (Phascolarctos cinereus)--organ distribution and histopathological findings.

Chlamydial infections in koalas can cause life-threatening diseases leading to blindness and sterility. However, little is known about the systemic spread of chlamydiae in the inner organs of the koala, and data concerning related pathological organ lesions are limited. The aim of this study was to perform a thorough investigation of organs from 23 koalas and to correlate their histopathological lesions to molecular chlamydial detection. To reach this goal, 246 formalin-fixed and paraffin embedded organ samples from 23 koalas were investigated by histopathology, Chlamydiaceae real-time PCR and immunohistochemistry, ArrayTube Microarray for Chlamydiaceae species identification as well as Chlamydiales real-time PCR and sequencing. By PCR, two koalas were positive for Chlamydia pecorum whereas immunohistochemical labelling for Chlamydiaceae was detected in 10 tissues out of nine koalas. The majority of these (n=6) had positive labelling in the urogenital tract related to histopathological lesions such as cystitis, endometritis, pyelonephritis and prostatitis. Somehow unexpected was the positive labelling in the gastrointestinal tract including the cloaca as well as in lung and spleen indicating systemic spread of infection. Uncultured Chlamydiales were detected in several organs of seven koalas by PCR, and four of these suffered from plasmacytic enteritis of unknown aetiology. Whether the finding of Chlamydia-like organisms in the gastrointestinal tract is linked to plasmacytic enteritis is unclear and remains speculative. However, as recently shown in a mouse model, the gastrointestinal tract might play a role being the site for persistent chlamydial infections and being a source for reinfection of the genital tract.

Aplicação da química quântica computacional no estudo de processos químicos envolvidos em espectrometria de massas

The field of application of mass spectrometry (MS) has increased considerably due to the development of ionization techniques. Other factors that have stimulated the use of MS are the tandem mass spectrometry (MS/MS) and sequential mass spectrometry (MSn) techniques. However, the interpretation of the MS/MS and MSn data may lead to speculative conclusions. Thus, various quantum chemical methods have been applied for obtaining high quality thermochemical data in gas phase. In this review, we show some applications of computational quantum chemistry to understand the formation and fragmentation of gaseous ions of organic compounds in a MS analysis.

The Hegel's Vorlesungen über die Philosophie der Religion (1821-1831) sources and critical editions from Marheineke to Jaeschke

In this paper I provide a concise plan about Hegel's Lectures on the Philosophy of Religion critical editions, laying stress on the method followed by editors in order to build a coherent text with the sources at their disposal. The Marheineke's edition (1832) is analysed with special attention since it was the edition that caused the division between a Right and a Left, opening the discussion on speculative theism as a consequence of the difficulty to distinguish the systematic part from the historical one in the reasoning carried out by Hegel.