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Distribution by Scientific Domains


Selected Abstracts


Evidence-based practice and the professionalization of dental hygiene

INTERNATIONAL JOURNAL OF DENTAL HYGIENE, Issue 4 2004
Sandra J Cobban
Abstract: The application of knowledge is fundamental to human problem solving. In health disciplines, knowledge utilization commonly manifests through evidence-based decision making in practice. The purpose of this paper is to explore the development of the evidence-based practice (EBP) movement in health professions in general, and dental hygiene in particular, and to examine its relationship to the professionalization agenda of dental hygiene in Canada. EBP means integrating practitioner expertise with the best available external evidence from research. Proponents of EBP believe that it holds promise for reducing a research,practice gap by encouraging clinicians to seek current research results. Both the Canadian and American Dental Hygienists Associations support practice based on current research evidence, yet recent studies show variation in practice. Professionalization refers to the developmental stages through which an organized occupation passes as it develops traits that characterize it as a profession. The status conferred by professionalization privileges a group to make and monitor its own decisions relative to practice. Dental hygiene's success in acquiring attributes of a profession suggests that transformation to a profession is occurring. This paper compares the assumptions and challenges of both movements, and argues the need for a principal focus on the development of a culture of evidence-based dental hygiene practice. [source]


Design of novel microstrip low-pass filter using defected ground structure

MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 1 2008
Petr Vágner
Abstract A novel microstrip low-pass filter utilizing defected ground structure (DGS) units is presented in this article. A DGS unit is simulated with different physical dimensions in order to show variation of attenuation pole and cut-off frequency. Next, a low-pass filter using proposed DGS unit is designed. A method for determining dimensions of microstrip structure and DGS units is proposed. Influence of dimensions of the microstrip structure on filter characteristics is investigated and simulated. Filters of various orders are simulated as well. Selected filter is simulated and experimentally verified. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 10,13, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22982 [source]


Assessing reproductive profiles in female brown mouse lemurs (Microcebus rufus) from Ranomafana National Park, southeast Madagascar, using fecal hormone analysis

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 6 2009
Marina B. Blanco
Abstract Studies on reproductive endocrinology in wild primate populations have greatly increased in the last decades owing to the development of noninvasive techniques that can be applied under field conditions. However, small-bodied nocturnal species are not well represented on the long list of primates surveyed in the wild, and reproductive inferences regarding these animals in their natural habitats have not benefited from direct observations of hormonal changes. We collected fecal samples from female brown mouse lemurs (Microcebus rufus) in a southeastern rainforest of Madagascar in order to determine whether or not fecally excreted steroid levels show a consistent pattern of change during the reproductive season and are a useful complement to reproductive observations in wild-trapped individuals. Initial data show variation in reproductive hormone levels before and after estrus and estimated day of parturition. Elevated levels of excreted estradiol (E2) were observed around the time of estrus, whereas high levels of fecal progesterone (P) were seen during later stages of pregnancy and around parturition. A more complete picture of reproductive profiles in female mouse lemurs, and how they may change over the life span, can be obtained if hormone analyses are used to supplement field observations. Am. J. Primatol. 71:439,446, 2009. © 2009 Wiley-Liss, Inc. [source]


THE TYCHOPELAGIC DIATOM, PARALIA SULCATA, AS PALEOINDICATOR SPECIES IN COASTAL MARINE ENVIRONMENTS

JOURNAL OF PHYCOLOGY, Issue 2000
M.R. McQuoid
Paralia sulcata is a diatom commonly found in both the plankton and benthos of coastal environments. This species is heavily silicified and, thus preserves well in sedimentary records making it a potentially useful paleoindicator species. However, its tychopelagic nature and its association with a wide range of environmental conditions have made detailed paleoecological interpretations complicated. High-resolution sediment records from coastal fjords in both Canada and Sweden show variations in the abundance and morphology of P. sulcata that provide evidence of changes in benthic habitat distribution and surface water properties in the fjords on timescales of decades to centuries. These studies suggest that P. sulcata can be an important paleoindicator species when interpretations are made in the context of its complex ecology. [source]


Identification of arid phases during the last 50,cal. ka BP from the Fuentillejo maar-lacustrine record (Campo de Calatrava Volcanic Field, Spain),

JOURNAL OF QUATERNARY SCIENCE, Issue 7 2010
Juana Vegas
Abstract Geochemical (element analysis, molecular analysis of organic compounds), physical, palynological, mineralogical and sedimentary facies analysis were performed to characterise the sedimentary record in Fuentillejo maar-lake in the Central Spanish Volcanic Field of Campo de Calatrava, in order to reconstruct the palaeoenvironmental and palaeoclimatic processes which controlled vegetation patterns and deposition of different sedimentary facies. The upper 20,m of core FUENT-1 show variations in clastic input, water chemistry, vegetation and organic fraction sources in the lake throughout the Late Pleistocene and Holocene. The temporal framework provided by 14C accelerator mass spectrometry dating allows assigning the sequence to the last 50,cal. ka BP. Arid phases identified in the FUENT-1 sequence are correlated to Heinrich events (HE) and to stadials of the Dansgaard/Oeschger (D/O) cycles. Siliciclastic facies with high magnetic susceptibility values, high Juniperus pollen content, a low Paq index (aquatic macrophysics proxy index), a decrease in the relative percentage of the n -C27 and an increase in the n -C31 alkanes are indicative of arid and colder climatic events related to HE 2, HE 1 and the Younger Dryas (YD). Similar short cold and arid phases during the Holocene were identified at 9.2,8.6, 7.5,7 and 5.5,5,cal. ka BP. In dolomite,mud facies, the pollen data show an increase in the herbs component, mainly , Chenopodiaceae, Artemisia and Ephedra , steppe taxa; a low Paq index, a decrease in the relative percentage of the n -C27 alkane and an increase in the n -C31 alkane are also observed. This facies was probably the result of lower lake levels and more saline,alkaline conditions, which can be interpreted as linked to arid,warm periods. These warm and arid phases were more frequent during Marine Isotope Stage (MIS) 3 and the interstadials of MIS 2. HE 4, HE 2, HE 1 and the YD in core FUENT-1 were immediately followed by increases of warm steppe pollen assemblages that document rapid warming similar to the D/O cycles but do not imply increasing humidity in the area. Fuentillejo hydrology is controlled by changes in the atmospheric and oceanic systems that operated on the North Atlantic region at millennial scale during the last 50,cal. ka BP. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Time-series photometric spot modelling , VI.

ASTRONOMISCHE NACHRICHTEN, Issue 3 2003
A new computer code, its application to 23 years of photometry of the active giant IM Pegasi
Abstract We present and apply a new computer program named SpotModeL to analyze single and multiple bandpass photometric data of spotted stars. It is based on the standard analytical formulae from Budding and Dorren. The program determines the position, size, and temperature of up to three spots by minimizing the fit residuals with the help of the Marquardt-Levenberg non-linear least-squares algorithm. We also expand this procedure to full time-series analysis of differential data, just as real observations would deliver. If multi-bandpass data are available, all bandpasses can be treated simultaneously and thus the spot temperature is solved for implicitly. The program may be downloaded and used by anyone. In this paper, we apply our code to an ,23 year long photometric dataset of the spotted RS CVn giant IM Peg. We extracted and modelled 33 individual light curves, additionally, we fitted the entire V dataset in one run. The resulting spot parameters reflect the long term light variability and reveal two active longitudes on the substellar point and on the antipode. The radius and longitude of the dominant spot show variations with 29.8 and 10.4 years period, respectively. Our multicolour data suggests that the spot temperature is increasing with the brightening of the star. The average spot temperature from V, IC is 3550 ± 150 K or approximately 900 K below the effective temperature of the star. [source]