Testing and inference for fixed times of discontinuity in semimartingales

Bernoulli ◽  
2020 ◽  
Vol 26 (4) ◽  
pp. 2907-2948
Author(s):  
Viktor Todorov
Keyword(s):  
Author(s):  
Aaron Saiger

The bricks-and-mortar schools contemplated by American education law and regulation are discrete, bureaucratic institutions, where children interact in person with one another, and with adults who supervise them, inside fixed physical borders at fixed times. Their governance is likewise defined geographically. Virtual schooling, by contrast, is untethered from geography, is ubiquitously asynchronous, and involves the interaction of machine representations of people rather than of people themselves. Virtuality privileges the consumer over the bureaucrat, encourages the disaggregation and recombination of educational components on a bespoke basis, and brings different economies of scale and competitive features to the educational marketplace. The education law we have—the law of the traditional, embodied school—fits virtual technology poorly in critical respects. Virtuality demands fundamentally new legal approaches to areas as diverse as curriculum, attendance, student health and safety, privacy, parental responsibility, disability, student rights, discipline, governance, and equity. Responding to these demands provides occasion to see the law afresh, to reassess and redirect, to align principle and practice more closely, and ultimately to transform educational regulation in the service of equity and learning. This is an opportunity of a kind that has not presented itself since the beginning of the Progressive Era.


Author(s):  
Ayman G. EL Nagar ◽  
Manuel Baselga ◽  
Carlos Mínguez ◽  
María A. Santacreu ◽  
Juan Pablo Sánchez
Keyword(s):  

1998 ◽  
Vol 1998 ◽  
pp. 127-127
Author(s):  
B M L McLean ◽  
J J Hyslop ◽  
A C Longland ◽  
D Cuddeford

Cereal grains are often subjected to physical processing before being fed to equids. However, little information is available on how physical processing of cereals affects degradation dynamics in equids. This experiment examines the effect of two physical processing methods (micronisation and extrusion) on in situ degradation of barley in the caecum of poniesThree caecally fistulated mature Welsh-cross pony geldings (approx. LW 270kg) were offered ad libitum grass hay plus minerals. Incubation bags (monofilament polyester 6.5 x 20cm, 41μm pores, 16mg/cm2 sample size) containing either unprocessed barley (UB), micronised barley (MB) or extruded barley (EB) were incubated in the caecum for fixed times according to both a forward (0, 2, 4, 6, 12, 8, 24, 48h) and reverse (48, 24, 8, 4, 12, 6, 2, 0h) incubation sequence. For each feedstuff residues from each time were bulked within pony and across incubation sequence for subsequent analysis of dry matter (DM) and starch (STC). Degradation profiles were fitted to the DM and STC disappearance data according to Ørskov and McDonald (1979).


1968 ◽  
Author(s):  
Αναστάσιος Εμμανουήλ

The kinetics of ammonia between blood and peritoneal fluid on 18 patiens was studied. Ten grams of ammonium citrate were given by mouth; the concentrations of ammonia in the blood and in the peritoneal fluid were comprared after determining the values at fixed times. The cases were divided in two groups: group 1, included eight patients with cirrhosis of the liver, group 2, included patients with ascites of other than liver cirrhosis aetiology, five of whom had carcinoma of the liver and'or of the peritoneal, two patients with lymphosarcoma, one with kidneysarcoma (Bour neville Syndrome) and two cases with congestive heart failure. The following conclusions have drawn : 1. The ammonia concentrations in the ascitic fluid of the cirrhotic group (group 1) before ammonium citrate loading was found to be higher than in the blood. 2. The highest concentration of the ammonia in the ascitic fluid was found two hours after loading and fell to the pre-loading level three hours later. 3. The curve formed by the ammonia values and ascitic fluid is similar to that of the blood. 4. The values of blood —and ascitic fluid—ammonia and the respective ourves in cases of cardiac failure resembled those found in cirrhotics. 5. In cases of neoplasms the fluctuations of ammonia concentrations in the blood and in the peritoneal fluid are minimal and the curves are flat. 6. In lymphosarcoma and kidneysarcoma the pre-loading values of blood ammonia are higher than in the peritoneal fluid.7. High concentration of blood and peritoneal fluid ammonia without appreciable fluctuations might suggest liver cancer on cirrhotic substrate.


1981 ◽  
Vol 59 (10) ◽  
pp. 1380-1390 ◽  
Author(s):  
J. M. Dewey ◽  
D. J. McMillin

High speed photogrammetry has been used to measure the particle trajectories in the flows resulting from the interaction of two identical explosively produced spherical shock waves. It is postulated that the interaction simulated the reflection of a spherical shock from an ideal nonenergy-absorbing surface. The "ideal" reflections were compared with reflections from two types of ground surface. From the observed particle trajectories the particle velocities, gas densities, and hydrostatic, dynamic, and total pressures in the complex air flows behind the shock interactions have been computed. These flows are described as two dimensional fields at fixed times and as time histories at fixed locations. The Mach stem shocks at the ground surfaces were weaker than those at corresponding positions near the interaction planes, but the magnitudes of the flow properties in these waves decreased more slowly and, at later times, became greater than those in the waves at the interaction planes. Computed pressure–time histories were compared to measurements made using electronic transducers and good agreement was found.


1970 ◽  
Vol 21 (5) ◽  
pp. 767 ◽  
Author(s):  
TJ Robinson ◽  
NW Moore ◽  
DR Lindsay ◽  
IC Fletcher ◽  
S Salamon

A number of treatments were used in association with Cronolone (Searl)- impregnated intravaginal spones in ewes which were artificially inseminated. Five factorial tests were conducted, involving 4880 ewes. Supplementary oestrogen (25 � oestradiol benzoate) or androgen (1 mg testosterone) given at the time of withdrawal of sponges after 16 days' insertion was of no benefit. Few extra ewes exhibited oestrus and fertility was lowered. Flushing the vagina with a mild disinfectant at the time of withdrawal of sponges had no advantage. Ewes came into oestrus earlier, but fertility was not improved. Factors in the tests which did affect fertility were: (a) amount of Cronolone absorbed, (b) time of onset in ewes inseminated on detection of oestrus, (c) time of insemination relative to time of withdrawal of the sponge in ewes inseminated on a fixed time basis, and (d) number of spermatozoa used in the inseminate. There also was an interaction between dilution of semen and number of spermatozoa in that high fertility was associated with maximum number and minimum volume (maximum density and number). Insemination once with 600 x l06 spermatozoa in 0.2 ml inseminate at fixed times of 36, 42, or 48 hr after withdrawal of sponges resulted in lambing in 50 % of ewes (60 of 120).


Author(s):  
Stefan C. Reif

Although some of the inspiration for later Jewish prayers undoubtedly came from the ancient Near East and the early books of the Hebrew Bible, there was at that early period of development little connection between the formal liturgy, as represented by the Temple cult, and the spontaneous entreaties of the individual. During the Second Temple period, the two methods of expression began to coalesce, and the literature included among the Dead Sea Scrolls testifies to the recitation of regular prayers at fixed times. The Talmudic rabbis laid down instructions for some statutory prayers, such as the shema‘ and the ‘amidah, and these gradually formed the basis of what became the synagogal liturgy.


2008 ◽  
Vol 100 (3) ◽  
pp. 1320-1331 ◽  
Author(s):  
Hilary W. Heuer ◽  
Stefanie Tokiyama ◽  
Stephen G. Lisberger

Under natural conditions, motor learning is instructed by sensory feedback. We have asked whether sensory signals that indicate motor errors are necessary to instruct learning or if the motor signals related to movements normally driven by sensory error signals would be sufficient. We measured eye movements in trained rhesus monkeys while employing electrical microstimulation of the floccular complex of the cerebellum and the smooth eye movement region of the frontal eye fields to alter ongoing pursuit eye movements. Repeated electrical stimulation at fixed times after the onset of target motion and pursuit failed to cause any learning that was retained beyond the time period used to instruct learning. Learning was not uncovered when the target was stabilized with respect to the moving eye to prevent competition between instructive signals created by electrical stimulation and visual image motion signals evoked when stimulation drove the eye away from the tracking target. We suggest that signals emanating from motor-related structures in the pursuit circuit do not instruct learning. Instead, instructive sensory error signals seem to be necessary.


1989 ◽  
Vol 256 (2) ◽  
pp. R379-R393 ◽  
Author(s):  
J. Bajic ◽  
E. J. Zuperku ◽  
F. A. Hopp

To characterize the dynamics of the control of respiratory I-beta neurons by slowly adapting pulmonary stretch receptors, the neuronal discharge responses to lung inflation and electrically induced vagal input patterns were analyzed. Unitary recordings from single medullary I-beta neurons and whole phrenic nerve activity were recorded in chloralose-urethan-anesthetized paralyzed cats. Neuronal discharge patterns were quantified in terms of cycle-triggered histograms. The net response to a test afferent input pattern generated during neural inspiration was expressed as the difference between the central component of I-beta activity and the total response. The central component was obtained during control respiratory cycles in which lung inflation occurred during neural expiration and no vagal feedback occurred during neural inspiration. For a set of test inflations with different ramp rates, the net responses, measured at fixed times with respect to the onset of neural inspiration, were linearly related to transpulmonary pressure. However, the slopes of these relationships increased as a function of time during neural inspiration. Neuronal responses to electrically induced ramp vagal input patterns were similar to those produced by ramp inflation. The net response due to electrically induced ipsilateral step patterns consisted of a rapid excitatory and a slow inhibitory component, whereas only the slow inhibitory component was observed for contralateral patterns. The implications of these findings with respect to the modes of neural processing and effects on phrenic output patterns are discussed.


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