Discreteness without symmetry breaking: a theorem

This paper concerns sprinklings into Minkowski space (Poisson processes). It proves that there exists no equivariant measurable map from sprinklings to spacetime directions (even locally). Therefore, if a discrete structure is associated to a sprinkling in an intrinsic manner, then the structure will not pick out a preferred frame, locally or globally. This implies that the discreteness of a sprinkled causal set will not give rise to ``Lorentz breaking'' effects like modified dispersion relations. Another consequence is that there is no way to associate a finite-valency graph to a sprinkling consistently with Lorentz invariance.Comment: 7 pages, laTe

Discreteness and the transmission of light from distant sources

We model the classical transmission of a massless scalar field from a source to a detector on a background causal set. The predictions do not differ significantly from those of the continuum. Thus, introducing an intrinsic inexactitude to lengths and durations - or more specifically, replacing the Lorentzian manifold with an underlying discrete structure - need not disrupt the usual dynamics of propagation.Comment: 16 pages, 1 figure. Version 2: reference adde

Long-term polarization observations of Mira variable stars suggest asymmetric structures

Mira and semi-regular variable stars have been studied for centuries but continue to be enigmatic. One unsolved mystery is the presence of polarization from these stars. In particular, we present 40 years of polarization measurements for the prototype o Ceti and V CVn and find very different phenomena for each star. The polarization fraction and position angle for Mira is found to be small and highly variable. On the other hand, the polarization fraction for V CVn is large and variable, from 2 - 7 %, and its position angle is approximately constant, suggesting a long-term asymmetric structure. We suggest a number of potential scenarios to explain these observations.Comment: 2 pages, 1 figure, poster presented at IAU Symposium 301, Precision Asteroseismology, August 2013, Wroclaw, Polan

Gravity and Matter in Causal Set Theory

The goal of this paper is to propose an approach to the formulation of dynamics for causal sets and coupled matter fields. We start from the continuum version of the action for a Klein-Gordon field coupled to gravity, and rewrite it first using quantities that have a direct correspondent in the case of a causal set, namely volumes, causal relations, and timelike lengths, as variables to describe the geometry. In this step, the local Lagrangian density $L(f;x)$ for a set of fields $f$ is recast into a quasilocal expression $L_0(f;p,q)$ that depends on pairs of causally related points $p \prec q$ and is a function of the values of $f$ in the Alexandrov set defined by those points, and whose limit as $p$ and $q$ approach a common point $x$ is $L(f;x)$. We then describe how to discretize $L_0(f;p,q)$, and use it to define a discrete action.Comment: 13 pages, no figures; In version 2, friendlier results than in version 1 are obtained following much shorter derivation

Effect of Adult Attachment on the Resiliency of Youth in Behavior Disordered Classrooms

The purpose of this study was to investigate the effect that adult attachment has on the resiliency of at-risk youth . The Inventory of Parent and Peer Attachment was revised to measure the degree of attachment to a significant adult and was administered along with the Children\u27 s Resiliency Attitudes Scale to students in behavior disordered classrooms (n = 41). The assessments were given during one class period in six behavior disordered classrooms at one school. The results found that those students who feel strong attachments to at least one adult were also more resilient and able to deal with adversity. These findings emphasized the importance of involving adults from various facets of life and the community in the development of community and school based youth programs

Curing and storage of alfalfa hay

The difficulty in determining the stage of the curing process at any given time was largely overcome in these studies by the perfection of a weighing device which enabled the operator to determine the moisture content of the hay as it was being cured in the field. The presence of living cells in the stems and leaves of field-cured hay plants was shown. The evidence and theories on heating of hay indicate that heating is due largely to chemical oxidation processes. These processes may be helped along by the respiration of the living cells in the plant up to 40-45 °C. and by the work of microorganisms from air temperatures to 70° C. in producing unstable, unsaturated compounds. It is believed that beyond this point the heating is due entirely to chemical processes. Alfalfa hay was found to cure more rapidly in the swath than in the windrow and more rapidly in the windrow than when cocked. Hay that was one-fourth, one-half or three-fourths cured in the swath prior to windrowing cured more rapidly than the hay windrowed at once, and the longer the hay was allowed to remain in the swath, the less time was required for curing. Cocking hay, either at once or after partial swath Or windrow-curing, delayed the curing process. Green hay in large cocks heated and lost its color. Good quality hay was made by cocking after partial swath or windrow-curing. Turning average sized windrows with the rake in good curing weather was found to be slightly detrimental as no appreciable time was gained and the quality of the hay was slightly lowered. Turning large windrows or windrows wet by rain caused them to cure more rapidly and gave a better quality of hay. Tedding hay was not found to be advantageous in any way in these experiments and was detrimental to the quality of the hay. The tedder may be valuable in curing extremely heavy swaths of hay. Complete swath-curing resulted in the greatest loss of leaves; three-fourth and one-half swath-curing were next in amount of leaves lost. Windrowing at once and one-fourth swath-curing followed by windrowing resulted in the least loss of leaves. The leaf-loss in swath-curing hay was increased by the use of the tedder. The turning of the windrow with the rake caused an additional leaf-loss in windrow-cured hay. DurIng these experiments hay was placed in the mow with as low as 20 percent and as high as 58.7 percent of moisture. The degree of heating was not found to be directly proportional to the moisture content of the hay. Hay with below 30 percent of moisture ordinarily may be considered safe from heating to a destructive or dangerous degree. Hay with less than 27 percent of moisture may be expected to retain its green color. The hay generally heats immediately on being mowed, then cools; this is followed by a second heating period in which the highest temperature is usually reached in 8 to 10 days after mowing, after which the hay cools gradually. The amount of carbon dioxide present in the mow, is a fair indication of the degree of heating of the hay . . The accumulation of carbon dioxide in the presence of moist, hot material results in a transformation of the chlorophyll, accompanied by a change in color from green to brown. The green color of hay was usually destroyed when the heating exceeded 50°C. Clean, brown hay is formed at temperatures above 55°C. and below 70 °C. In general, moldy, grayish-brown hay results when hay heats to between 40 and 50°C. during the storage period. Clean, brown hay is formed by heating quickly to 55° C., while if the heating is prolonged at 50° C. or less and later heats to above 55°C., the hay is dusty. The value of salting hay in the mow was tested eight times, with a distinctly beneficial effect once, slightly beneficial once and apparently no benefit in six trials. When hay baled from the field with 23 percent of moisture was carefully stored, there was no detrimental heating

Age of second language acquisition affects nonverbal conflict processing in children : an fMRI study

Background: In their daily communication, bilinguals switch between two languages, a process that involves the selection of a target language and minimization of interference from a nontarget language. Previous studies have uncovered the neural structure in bilinguals and the activation patterns associated with performing verbal conflict tasks. One question that remains, however is whether this extra verbal switching affects brain function during nonverbal conflict tasks. Methods: In this study, we have used fMRI to investigate the impact of bilingualism in children performing two nonverbal tasks involving stimulus-stimulus and stimulus-response conflicts. Three groups of 8-11-year-old children - bilinguals from birth (2L1), second language learners (L2L), and a control group of monolinguals (1L1) - were scanned while performing a color Simon and a numerical Stroop task. Reaction times and accuracy were logged. Results: Compared to monolingual controls, bilingual children showed higher behavioral congruency effect of these tasks, which is matched by the recruitment of brain regions that are generally used in general cognitive control, language processing or to solve language conflict situations in bilinguals (caudate nucleus, posterior cingulate gyrus, STG, precuneus). Further, the activation of these areas was found to be higher in 2L1 compared to L2L. Conclusion: The coupling of longer reaction times to the recruitment of extra language-related brain areas supports the hypothesis that when dealing with language conflicts the specialization of bilinguals hampers the way they can process with nonverbal conflicts, at least at early stages in life