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In planning for PDF-3, the International Centre for Diffraction Data's full pattern database of raw diffraction data, it is evident that a standard format for storage and exchange of diffraction data is necessary. An evaluation of the JCAMP-DX protocol by a task group* of the International Centre for Diffraction Data has resulted in a set of format cooes specific to X-ray diffraction. The proposed structure of the data is divided into four parts: the minimal component set required by the JCAMP-DX definition (name, data, owner, sample identification, data type, etc.), a minimum item set required to define the X-ray diffraction data, an open selection of requested but not required information on the sample, its preparation and the instrument, and finally the data itself in one of several specified formats. All information stored in JCAMP-DX format is in ASCII characters. Therefore, these data are printable, easily read by the user and compatible with almost any computer or media storage device. Codes defining the information are primarily in shortened, but readable, English. The task group is completing the work on this project and will be presenting its proposals to JCAMP.
Among powder diffractionists, there is a concern about establishing criteria for testing existing and new computer methods for searching the Powder Diffraction File (PDF) data base. A large number of papers on this subject have been presented at recent Denver Conferences and at other meetings, such as the American Crystallographic Association.
The PDF now exceeds 42,000 patterns, with an average of about thirty lines per pattern. Thus, it contains approximately 2.5 million numerical values. At its current rate of growth, the PDF will double in less than twenty years.
The narrative works extremely hard to convince through evidence: we have a date, an eyewitness, and the events that inspired the song's conception. Since it is written in bronze and mounted on stone, the story seems fixed and immovable. However, cracks have begun to form in the beloved “Jingle Bells” narrative, and as with many such sentimental stories, we find there is always more to uncover. This essay confronts one of the most popular Christmas carols of all time: “Jingle Bells; or, The One Horse Open Sleigh,” whose history has usually been told in relation to a singular event—“Where was it first written?” The answer depends on where you ask, since both Medford, Massachusetts and Savannah, Georgia lay claim to being the song's city of origin. Commemorative plaques can be found in both cities, and this musical North–South discord carries on to this day.
Since its introduction into North America in the late nineteenth century, direct democracy, particularly in the form of direct legislation, has periodically piqued the interest of legal scholars. A handful of studies have examined the history of direct legislation in the United States and in Canada; however, these studies often fail to examine how direct legislation was actually used. Brief references might be given to which initiatives the voters attempted to secure via direct legislation, but the actual mechanics of the vote, and questions such as what the ballot said, for example, are typically overlooked.
The bran and particularly the aleurone fraction of wheat are high in betaine and other physiological methyl donors, which may exert beneficial physiological effects. We conducted two randomised, controlled, cross-over postprandial studies to assess and compare plasma betaine and other methyl donor-related responses following the consumption of minimally processed bran and aleurone fractions (study A) and aleurone bread (study B). For both studies, standard pharmacokinetic parameters were derived for betaine, choline, folate, dimethylglycine (DMG), total homocysteine and methionine from plasma samples taken at 0, 0·5, 1, 2 and 3 h. In study A (n 14), plasma betaine concentrations were significantly and substantially elevated from 0·5 to 3 h following the consumption of both bran and aleurone compared with the control; however, aleurone gave significantly higher responses than bran. Small, but significant, increases were also observed in DMG measures; however, no significant responses were observed in other analytes. In study B (n 13), plasma betaine concentrations were significantly and substantially higher following consumption of the aleurone bread compared with the control bread; small, but significant, increases were also observed in DMG and folate measures in response to consumption of the aleurone bread; however, no significant responses were observed in other analytes. Peak plasma betaine concentrations, which were 1·7–1·8 times the baseline levels, were attained earlier following the consumption of minimally processed aleurone compared with the aleurone bread (time taken to reach peak concentration 1·2 v. 2·1 h). These results showed that the consumption of minimally processed wheat bran, and particularly the aleurone fraction, yielded substantial postprandial increases in plasma betaine concentrations. Furthermore, these effects appear to be maintained when aleurone was incorporated into bread.
Introduction: Smokers unmotivated to quit are neglected by smoking cessation research. Free-text comment analysis is a potentially useful way to gain insight into this group's beliefs.
Aims: To analyse the free-text comments provided by smokers unmotivated to quit as part of a randomized controlled trial of computer-tailored feedback for smoking cessation.
Method: A random sample of 58,660 smokers were sent a smoking behaviour questionnaire (SBQ). The responses and follow-up outcomes of those providing free-text comments were compared to those who did not to assess the representativeness of the former group of smokers. The comments of participants unmotivated to quit (631) were thematically analysed.
Results: Those who provided a comment differed from those who did not on variables including education level and quit attempts at six-month follow-up. Emergent themes included; justification of smoking and restricting smoking instead of quitting.
Conclusions: The findings illustrate the value of free-text comments in identifying issues important to respondents. The identified themes highlight areas for future research in smokers unmotivated to quit including cutting down as a path to quitting and explicit messages regarding the inability of positive health behaviours to balance out the negative impact of smoking on health.
Trial registration: Current Controlled Trials ISRCTN05385712.
Anxiety disorders and insomnia significantly impair daily functioning. Similar underlying mechanisms may account for the high comorbidity of both disorders, and respective treatments share pharmacological and behavioural features. This review suggests the utility of an integrated CBT approach in the treatment of generalized anxiety, post-traumatic stress, and panic disorders, and comorbid insomnia. Other anxiety disorders were not explored because current data are limited or inconsistent. A comprehensive, non-systematic review of the literature was conducted to evaluate the treatment of comorbid anxiety and insomnia disorders, and data reveal shared pharmacological and behavioural features of insomnia and anxiety disorders treatment. However, research demonstrates that CBT maintains successful treatment results longer than drug therapies. Despite similar treatment approaches, there is a paucity of research that explores integrated CBT approaches for comorbid anxiety and insomnia disorders. This review suggests that future research should assess the impact of combined therapeutic approaches on the simultaneous reduction of anxiety disorders, insomnia, and relapse rates.
A concise but rigorous treatment of variational techniques, focussing primarily on Lagrangian and Hamiltonian systems, this book is ideal for physics, engineering and mathematics students. The book begins by applying Lagrange's equations to a number of mechanical systems. It introduces the concepts of generalized coordinates and generalized momentum. Following this the book turns to the calculus of variations to derive the Euler–Lagrange equations. It introduces Hamilton's principle and uses this throughout the book to derive further results. The Hamiltonian, Hamilton's equations, canonical transformations, Poisson brackets and Hamilton–Jacobi theory are considered next. The book concludes by discussing continuous Lagrangians and Hamiltonians and how they are related to field theory. Written in clear, simple language and featuring numerous worked examples and exercises to help students master the material, this book is a valuable supplement to courses in mechanics.
The purpose of this book is to give the student of physics a basic overview of Lagrangians and Hamiltonians. We will focus on what are called variational techniques in mechanics. The material discussed here includes only topics directly related to the Lagrangian and Hamiltonian techniques. It is not a traditional graduate mechanics text and does not include many topics covered in texts such as those by Goldstein, Fetter and Walecka, or Landau and Lifshitz. To help you to understand the material, I have included a large number of easy exercises and a smaller number of difficult problems. Some of the exercises border on the trivial, and are included only to help you to focus on an equation or a concept. If you work through the exercises, you will better prepared to solve the difficult problems. I have also included a number of worked examples. You may find it helpful to go through them carefully, step by step.