Letter from H. J. Frederick

Letter concerning a position in veterinary science at Utah Agricultural College

Circular No. 51 - Foot-and-Mouth Disease

The following is printed that the seriousness of the foot-and-mouth disease outbreak might be apparent to the farmers and ranchmen of Utah, that the importance of the quarantine regulations might be emphasized, that precautionary methods might be adopted by each individual concerned, that the disease might be recognized should it occur, and that each stock man of the state might see the importance of immediately reporting to the State Veterinarian or to a veterinarian in his locality or to the Utah Agricultural Experiment Station

Bulletin No. 223 - Feeding Value of Alfalfa Hay Treated with Calcium Arsenate

For a number of years many tons of sprayed or dusted hay have been fed successfully to livestock by stockmen interested in controlling the alfalfa weevil; nevertheless. the supposed cases of poisoning that have been reported naturally have caused concern among feeders. Further confusion on this question has resulted from reports on studies designed to determine the effect of lead arsenate instead of calcium arsenate. Whether the lead in lead arsenate has been a more injurious agent than the arsenic, of course, is difficult to state. Most of the experiments performed in the feeding of sprayed or dusted hay have been conducted with small experiment animals, as guinea pigs, rats, and rabbits. Despite the proven effectiveness of calcium arsenate in alfalfa weevil control, a number of stockmen are still doubtful as to the feeding value of hay from alfalfa thus treated, fearing it might be poisonous to livestock. As a rule, their fears in this respect are traceable to reports of poisoning based upon fallacious reports from different sources. Direct information on this subject is limited and difficult to obtain; especially is this true with calcium arsenate. In order to get direct information on the feeding value of alfalfa hay treated with calcium arsenate the study constituting the basis of this bulletin was undertaken

The effects of the exhaust plume on the lightning triggering conditions for launch vehicles

Apollo 12 and Atlas Centaur 67 are two launch vehicles that have experienced triggered lightning strikes. Serious consequences resulted from the events; in the case of Atlas Centaur 67, the vehicle and the payload were lost. These events indicate that it is necessary to develop launch rules which would prevent such occurrences. In order to develop valid lightning related rules, it is necessary to understand the effects of the plume. Some have assumed that the plume can be treated as a perfect conductor, and have computed electric field enhancement factors on that basis. The authors have looked at the plume, and believe that these models are not correct, because they ignore the fluid motion of the conducting plates. The authors developed a model which includes this flow character. In this model, the external field is excluded from the plume as it would be for any good conductor, but, in addition, the charge must distribute so that the charge density is zero at some location in the exhaust. When this condition is included in the calculation of triggering enhancement factors, they can be two to three times larger than calculated by other methods which include a conductive plume but don't include the correct boundary conditions. Here, the authors review the relevant features of rocket exhausts for the triggered lightning problem, present an approach for including flowing conductive gases, and present preliminary calculations to demonstrate the effect that the plume has on enhancement factors

Absolute Dynamical Limit to Cooling Weakly-Coupled Quantum Systems

Cooling of a quantum system is limited by the size of the control forces that are available (the "speed" of control). We consider the most general cooling process, albeit restricted to the regime in which the thermodynamics of the system is preserved (weak coupling). Within this regime, we further focus on the most useful control regime, in which a large cooling factor, and good ground-state cooling can be achieved. We present a control protocol for cooling, and give clear structural arguments, as well as strong numerical evidence, that this protocol is globally optimal. From this we obtain simple expressions for the limit to cooling that is imposed by the speed of control.Comment: 4 pages, Revetex4-1, 2 png figure

Differential Contributions of Three Parenting Dimensions to Preschool Literacy and Social Skills in a Middle-Income Sample

This study investigated parenting practices among families of preschoolers in a middle-income community, as well as the contributions of these practices to children\u27s literacy and learning-related social skills. A total of 229 families of preschoolers were recruited. Parents completed a survey describing their parenting practices, while children\u27s literacy skills were directly assessed by using standardized measures. Parents also reported on children\u27s social development. Factor analyses supported a three-dimensional structure of parenting including the home learning environment, autonomy support/expectations, and management/discipline. Path models showed that the home learning environment predicted literacy skills; specifically, parents\u27 teaching about letters and sounds was associated with alphabet knowledge, while shared book reading was marginally linked to vocabulary. Management/discipline was uniquely related to self-regulation, while cooperative/compliant skills were associated with the home learning environment, support/expectations, and management/discipline. Findings suggested that parenting could be conceptualized as three relatively independent dimensions, each of which demonstrated domain-specific contributions to early literacy and social skills

The Discovery of an Embedded Cluster of High-Mass Stars Near SGR 1900+14

Deep I-band imaging to approximately I = 26.5 of the soft gamma-ray repeater SGR 1900+14 region has revealed a compact cluster of massive stars located only a few arcseconds from the fading radio source thought to be the location of the SGR (Frail, Kulkarni, & Bloom 1999). This cluster was previously hidden in the glare of the pair of M5 supergiant stars (whose light was removed by PSF subtraction) proposed by Vrba et al. (1996) as likely associated with the SGR 1900+14. The cluster has at least 13 members within a cluster radius of approximately 0.6 pc, based on an estimated distance of 12-15 kpc. It is remarkably similar to a cluster found associated with SGR 1806-20 (Fuchs et al. 1999). That similar clusters have now been found at or near the positions of the two best-studied SGRs suggests that young neutron stars, thought to be responsible for the SGR phenomenon, have their origins in proximate compact clusters of massive stars.Comment: 5 pages, 3 figures, accepted Astrophysical Journal Letter

Convective Downmixing of Plumes in a Coastal Environment

This paper describes the results of an atmospheric tracer study in which sulfur hexafluoride (SF_6) was used to investigate the transport and dispersion of effluent from a power plant located in a coastal environment. The field study demonstrated that material emitted into an elevated stable layer at night can be transported out over the ocean, fumigated to the surface, and then he returned at ground level by the sea breeze on the next day. At night when cool stable air from the land encounters the warmer ocean convective mixing erodes the stable layer forming an internal boundary layer. When the growing boundary layer encounters an elevated plume the pollutant material, entrained at the top of the mixed layer, can be rapidly transported in ∼20 min to the surface. Various expressions for the characteristic downmixing time (λ = Z_i/w_*) are developed utilizing the gradient Richardson number, the Monin-Obukhov length and turbulence intensifies. Calculations using these expressions and the field data are compared with similar studies of convective mixing over the land