Seeding of supercooled polyethylene with extended chain crystals

Seeding of supercooled polyethylene with extended chain crystal

Coulomb-Volkov approach of ionization by extreme ultraviolet laser pulses in the subfemtosecond regime

In conditions where the interaction betweeen an atom and a short high-frequency extreme ultraviolet laser pulse is a perturbation, we show that a simple theoretical approach, based on Coulomb-Volkov-type states, can make reliable predictions for ionization. To avoid any additional approximation, we consider here a standard case : the ionization of hydrogen atoms initially in their ground state. For any field parameter, we show that the method provides accurate energy spectra of ejected electrons, including many above threshold ionization peaks, as long as the two following conditions are simultaneously fulfilled : (i) the photon energy is greater than or equal to the ionization potential ; (ii) the ionization process is not saturated. Thus, ionization of atoms or molecules by the high order harmonic laser pulses which are generated at present may be addressed through this Coulomb-Volkov treatment.Comment: 19 pages including 5 figures and figure caption

Interference effects in two-photon ATI by multiple orders high harmonics with random or locked phases

We numerically study 2-photon processes using a set of harmonics from a Ti:Sapphire laser and in particular interference effects in the Above Threshold Ionization spectra. We compare the situation where the harmonic phases are assumed locked to the case where they have a random distribution. Suggestions for possible experiments, using realistic parameters are discussed.Comment: 11 pages, 13 figures, LaTe

Health literacy: the knowledge and experiences of senior level baccalaureate nursing students

The purpose of this study was to assess the health literacy knowledge and experiences of senior level baccalaureate nursing students enrolled at state universities in Louisiana. Three hundred and sixty-one students from eight baccalaureate nursing programs agreed to participate in the study. The Health Literacy Knowledge and Experience Survey (HL-KES) was utilized to measure the health literacy knowledge and experiences of participants. Participants were able to identify low socioeconomic groups as high risk for low health literacy skills and were strongly aware of the consequences associated with low health literacy skills. Knowledge gaps were evident in the following areas: identifying the older adult as a high risk group, health literacy screening, and guidelines for written healthcare information. A nine-item likert-type scale was utilized to measure health literacy experiences. Responses suggest that participants\u27 health literacy experiences are somewhat limited particularly with regards to assessing the reading level, appropriate use of illustrations, and cultural relevance of healthcare materials. A factor analysis revealed two factors labeled, Core and Technology that explained 57.15% of the variance in health literacy experiences. A negatively weak statistically significant relationship existed between health literacy experiences and health literacy knowledge. In addition, multiple regression analysis revealed that Technology Health Literacy Experiences, certification in an area of healthcare, grade point average, age, and ethnicity explained 11.6% of the variance in health literacy scores

A Review of the Principles and Benefits of Cue-Based Feeding

Literature reflects that neonatal clinical practices are increasingly infant-driven, and promote, developmentally based care. Particularly, in the area of oral feeding, practitioners are moving away from traditional gestational age criteria for the initiation of oral feeding, or progressing feedings based on volume, instead they are trending toward feeding protocols that are based on developmental maturity. A statement released by the American Academy of Pediatrics (2008), made the attainment of independent oral feeding one of the critical criteria for hospital discharge of preterm infants. This statement not only reflected the increased research attention on oral feeding acquisition and outcomes, it caused neonatal clinicians to seriously reconsider their methods for feeding premature infants, so that premature infants could safely acquire oral feeding prior to going home. This paper reviews and summarizes the principles and benefits of cue-based feeding that have been presented in the literature. Cue-based feeding is an outgrowth of developmentally-based care. Being increasingly used in feeding plans for premature infants, cue-based feeding is a feeding method, where, the infant directs how and when it will eat, by displaying behavioral cues and eating reflexes

Sociolinguistic variation in the nativisation of BSL fingerspelling

British Sign Language (BSL) is a visual-gestural language distinct from spoken languages used in the United Kingdom but in contact with them. One product of this contact is the use of fingerspelling to represent English words via their orthography. Fingerspelled loans can become “nativised”, adapting manual production to conform more closely to the native lexicon’s inventory of phonemic constraints. Much of the previous literature on fingerspelling has focused on one-handed systems but, unlike the majority of sign languages, BSL uses a two-handed manual alphabet. What is the nature of nativisation in BSL, and does it exhibit sociolinguistic variation? We apply a cross-linguistic model of nativisation to BSL Corpus conversation and narrative data (http://bslcorpusproject.org) obtained from 150 signers in 6 UK regions. Mixed effects modelling is employed to determine the influence of social factors. Results show that the participants’ home region is the most significant factor, with London and Birmingham signers significantly favouring use of fully nativised fingerspelled forms. Non-nativised sequences are significantly favoured in signers of increasing age in Glasgow and Belfast. Gender and parental language background are not found to be significant factors in nativisation. The findings also suggest a form of reduction specific to London and Birmingham

Speeding up simulations of relativistic systems using an optimal boosted frame

It can be computationally advantageous to perform computer simulations in a Lorentz boosted frame for a certain class of systems. However, even if the computer model relies on a covariant set of equations, it has been pointed out that algorithmic difficulties related to discretization errors may have to be overcome in order to take full advantage of the potential speedup. We summarize the findings, the difficulties and their solutions, and show that the technique enables simulations important to several areas of accelerator physics that are otherwise problematic, including self-consistent modeling in three-dimensions of laser wakefield accelerator stages at energies of 10 GeV and above.Comment: To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C09072