Estimating Multi-Beta Pricing Models : With or Without an Intercept: Further Results from Simulations

The two-pass method is a common approach for estimating risk premia and examining factor pricing models. It consists of a time-series regression (first-pass) and a cross-sectional regression (second-pass). Two common problems of this approach are the downward bias of the estimates and the large standard error of the estimates. A previous study showed through a simulation approach that the problem of the bias can be mitigated by running at least one of the two regressions without an intercept, whereas the problem of the large standard error can be mitigated by running the second regression without an intercept. The previous study used a single factor pricing model as the underlying model for its simulation. The objective of this thesis was to provide further evidence for this mitigation method (leaving out the intercepts) by analyzing the mitigating effects in the case of the Fama and French three-factor model. For this purpose, the simulation was based on the simulation of the previous study and was extended to suit the properties of the threefactor model. The simulation comprised two main parts: first, the test data was generated artificially, then the two-pass method was applied on each set of this generated data. Similar to the findings of the underlying study, it was found that omitting the intercept in at least one of the two regressions decreases the bias of the estimated market premium. Furthermore, omitting the intercept in the cross-sectional regression decreases the standard deviation of the market premium estimates. However, for the two additionally estimated risk premiums (size and value), the mitigating effect on the biases is hardly observable, as the biases of these estimates are already small without omitting the intercept in either of the two regressions. Moreover, the standard errors of the estimates for the size and value premiums did not decrease when the intercept was omitted in at least one of the regressions. In all of the applied variants, the standard error of the estimates for the three premiums are persistently large. Therefore, even with this partially effective mitigation method, it remains difficult to draw statistical conclusions from the two-pass method

Temporomandibulaarsed häired

Temporomandibulaarsed häired (TMH) on muskuloskeletaalsed häired, mis haaravad temporomandibulaarliigest, mälumislihaseid ja kõiki nendega seotud kudesid. TMHsid klassifitseeritakse järgmiselt: müalgiad, artralgiad, intraaurikulaarsed häired ja TMHga seotud peavalu. Iseloomulik on valu alalõualiigese piirkonnas, mis kiirgub kõrva ette, oimupiirkonda ja kaela, võib esineda liigese liikuvuse piiratus ja krepitatsioon. Sagedamini haigestuvad naised. Valulik TMH võib areneda krooniliseks valuks. Ravi on enamikul juhtudest konservatiivne.Artikli eesmärk on eelkõige tutvustada TMHsid arstidele, kes ei ole spetsialiseerunud suu- ja hambahaigustele.Eesti Arst 2016; 95(7):455–45

Evaluation von Ausdauer-Assessments : Reliabilität, Validität und Praxistauglichkeit von Ausdauer-Assessments in Bewegungsgruppen für Betroffene mit ankylosierender Spondylitis

Darstellung des Themas: Von ankylosierender Spondylitis (AS) betroffene Personen haben krankheitsbedingt ein erhöhtes Risiko für kardiovaskuläre Erkrankungen und profitieren von zusätzlichem kardiovaskulärem Training. Für die Verlaufsdokumentation des Ausdauertrainings eignen sich Assessments. Dabei stellt sich die Frage, welche validierten Ausdauer-Assessments für SVMB-Bewegungsgruppen geeignet sind. Ziel: Diese Arbeit soll aufzeigen, welche Ausdauer-Assessments sich zur Evaluation der Ausdauerkapazität von AS-Betroffenen eignen. Sie müssen reliabel und valide sein, die Kriterien der Assessmentökonomie erfüllen und sich insbesondere für AS-Betroffene eignen. Methode: Zu Beginn wird ein Überblick über die existierenden Ausdauer-Assessments geschaffen. Nach einer ersten Selektion folgt eine Analyse, in welcher die Assessments mittels anerkannten Kriterien für Assessmentökonomie auf ihre Praxistauglichkeit überprüft werden. Für die verbleibenden Assessments wird in den Datenbanken PubMed, Pedro und Cochrane Library nach Reliabilitäts- und Validitätsstudien gesucht. Resultate: Als praxistauglich erweisen sich sechs Ausdauer-Assessments, davon wurde jedoch keines an AS-Betroffenen validiert. Studien, in welchen die Reliabilität und Validität von Ausdauer-Assessments untersucht werden, wurden überwiegend an gesunden Erwachsenen, Sportlern oder Kindern durchgeführt. Schlussfolgerung: Eines der sechs Ausdauer-Assessments ist der Cooper-Test, ebenfalls bekannt als 12min-Lauf. Diesen Test empfiehlt die Autorin für den praktischen Einsatz in SVMB-Bewegungsgruppen. Zudem besteht Bedarf, ein praxistaugliches Ausdauer-Assessment an AS-Betroffenen zu validieren

Kiri Karl Morgensternile, Dorpat

L. 4-5 kirjale lisatud 2 luuletust: An meinen kleinen Garten am 26. May 1826 ; am 6. Juny / Friedr. Akermannhttp://tartu.ester.ee/record=b1844404~S1*es

Savi valdkonna käsiraamat

TäistekstKäsiraamatu tellija: Setomaa Valdade Liit ja Ape vald, Eesti-Läti koostööprojekti "BUY LOCAL" raame

Heat acclimatization blunts copeptin responses to hypertonicity from dehydrating exercise in humans.

Acclimatization favors greater extracellular tonicity from lower sweat sodium, yet hyperosmolality may impair thermoregulation during heat stress. Enhanced secretion or action of vasopressin could mitigate this through increased free water retention. Aims were to determine responses of the vasopressin surrogate copeptin to dehydrating exercise and investigate its relationships with tonicity during short and long-term acclimatization. Twenty-three participants completed a structured exercise programme following arrival from a temperate to a hot climate. A Heat Tolerance Test (HTT) was conducted on Day-2, 6, 9 and 23, consisting of 60-min block-stepping at 50% VO2 peak, with no fluid intake. Resting sweat [Na+ ] was measured by iontophoresis. Changes in body mass (sweat loss), core temperature, heart rate, osmolality (serum and urine) and copeptin and aldosterone (plasma) were measured with each Test. From Day 2 to Day 23, sweat [Na+ ] decreased significantly (adjusted P < 0.05) and core temperature and heart rate fell. Over the same interval, HTT-associated excursions were increased for serum osmolality (5 [-1, 9] vs. 9 [5, 12] mosm·kg-1 ), did not differ for copeptin (9.6 [6.0, 15.0] vs. 7.9 [4.3, 14.7] pmol·L-1 ) and were reduced for aldosterone (602 [415, 946] vs. 347 [263, 537] pmol·L-1 ). Urine osmolality was unchanging and related consistently to copeptin at end-exercise, whereas the association between copeptin and serum osmolality was right-shifted (P = 0.0109) with acclimatization. Unchanging urine:serum osmolality argued against increased renal action of vasopressin. In conclusion, where exercise in the heat is performed without fluid replacement, heat acclimatization does not appear to enhance AVP-mediated free water retention in humans

Cahiers des charges et circuits courts

National audienc