192 research outputs found
A computer-based plant/soil-aeration bibliography
Numerous reviews of the general topic of plant and soil aeration
have appeared in the past generation. Two comprehensive recent
examples are Kozlowski (1984) and Glinaki and Stepniewski (1985).
Each is excellently documented and thoroughly covers its subject
matter, though perhaps from somewhat divergent perspectives. As
might be expected the source of citations contained in each volume's
bibliography largely reflects the geographical orientation and
principal area of expertise of the contributors. In each case,
undoubtedly, the authors compiled large collections of reprints and
second-source citations which were summarized and synthesized
into reviews. In the process, the authors characterized the citations
of which they were aware, eliminated some of these from
final use in the reviews, and probably missed some citations in the
literature.
The nature of review writing, until only recently, has demanded
that these efforts be largely individual, uncoordinated,
tedious, and transitory (the work of collecting and compiling the
information is usually lost with the author's shift of interest,
retirement, or other activity-influencing career changes). Occasionally
such a bibliography may be handed down from major
professor to student. Even in these cases, however, the bibliographies
are not widely available.
The advent of computer-based information storage and retrieval
has created new opportunities. Commercial literature retrieval
services exist that scan organized data bases (e.g. SCI
SEARCH* and DIALOG). Even with the continued expansion of the
data bases of these systems they have certain shortcomings. For
the unfamiliar users of these systems there is usually difficulty in
limiting the searches sufficiently to retrieve only desired citations
without excluding elusive citations that may be unconventionally
titled or that may not contain certain specific keywords needed to
retrieve the desired citations. Commercial literature retrieval can
also prove to be expensive for some users, particularly if a comprehensive
retrospective search is desired.
If a subject matter area were sufficiently limited in scope it
could be possible for a few interested researchers cooperatively to
compile a highly comprehensive listing of the relevant literature. A
familiar example of such effort was the compilation of a bibliography
on the topic of 15N by Hauck and Bystrom (1970). Their
bibliography, published as a book, provided an excellent fixed
resource, but one which lacked the capacity to grow or be manipulated.
The advent of powerful microcomputers and inexpensive
data-base software now enables the compilation of highly specific
manipulable bibliographies. These bibliographies offer the advantage
of being indexed by author, date, keywords, etc., of being
sorted by subcategories, and of being copied and shared in a
compact format (e.g. on floppy disk, tape, EPROM), and easily
updated and expanded
Smoking cigarettes of low nicotine yield does not reduce nicotine intake as expected: a study of nicotine dependency in Japanese males
BACKGROUND: Many Japanese believe that low-yield cigarettes are less hazardous than regular cigarettes, and many smokers consume low-yield cigarettes to reduce their risks from smoking. We evaluate the association between actual nicotine intake and brand nicotine yield, and the influence of nicotine dependence on this association. METHODS: The study subjects included 458 Japanese male smokers, aged 51.2 Β± 9.9 years, who participated in health check-ups in a hospital in 1998 and 2000. Each subject filled out a self-administered smoking questionnaire and the score of each on the FagerstrΓΆm Test for Nicotine Dependence was calculated. Urinary cotinine concentration was measured at the time of participation. RESULTS: The geometric mean of urinary cotinine concentration was 535 ng/mgCr for those who smoked brands with the lowest nicotine (0.1 mg on the package), compared with 1010 ng/mgCr for those who smoked brands with the highest (0.9β2.4 mg, weighted mean of 1.1 mg). Thus, despite the 11-fold ratio of nicotine yield on the packages, the ratio of urinary cotinine level was less than twofold. Both nicotine yield on the package and nicotine dependence significantly increased urinary cotinine concentration, and the negative interaction between them almost attained statistical significance. Cotinine concentration in heavily dependent smokers was consistently high regardless of the nicotine yield of brands. CONCLUSIONS: The nicotine yield of cigarettes measured by machine-smoking does not reliably predict the exposure of smokers. Smokers consuming low-yield nicotine cigarettes did not reduce actual intake of nicotine to the level that might be expected, especially for those heavily dependent on nicotine. Current labeling practices are misleading for the two-third of smokers who are moderately or highly dependent on nicotine
An Automated Method to Quantify Microglia Morphology and Application to Monitor Activation State Longitudinally In Vivo
Microglia are specialized immune cells of the brain. Upon insult, microglia initiate a cascade of cellular responses including a characteristic change in cell morphology. To study the dynamics of microglia immune response in situ, we developed an automated image analysis method that enables the quantitative assessment of microglia activation state within tissue based solely on cell morphology. Per cell morphometric analysis of fluorescently labeled microglia is achieved through local iterative threshold segmentation, which reduces errors caused by signal-to-noise variation across large volumes. We demonstrate, utilizing systemic application of lipopolysaccharide as a model of immune challenge, that several morphological parameters, including cell perimeter length, cell roundness and soma size, quantitatively distinguish resting versus activated populations of microglia within tissue comparable to traditional immunohistochemistry methods. Furthermore, we provide proof-of-concept data that monitoring soma size enables the longitudinal assessment of microglia activation in the mouse neocortex imaged via 2-photon in vivo microscopy. The ability to quantify microglia activation automatically by shape alone allows unbiased and rapid analysis of both fixed and in vivo central nervous system tissue
Transabdominal Preperitoneal Repair for Obturator Hernia
δΏ‘ε·ε€§ε¦ε士οΌε»ε¦οΌγ»ε¦δ½θ«ζγ»εΉ³ζ23εΉ΄3ζ31ζ₯ζδΈοΌη²η¬¬889ε·οΌγ»ζ¨ͺε±±ιη§Background A laparoscopic surgical approach for obturator hernia (OH) repair is uncommon. The aim of the present study was to assess the effectiveness of laparoscopic transabdominal preperitoneal (TAPP) repair for OH. Methods From 2001 to May 2010, 659 patients with inguinal hernia underwent TAPP repair at in our institutes. Among these, the eight patients with OH were the subjects of this study. Results Three of the eight patients were diagnosed as having occult OH, and the other five were diagnosed preoperatively, by ultrasonography and/or computed tomography, as having strangulated OH. Bilateral OH was found in five patients (63%), and combined groin hernias, either unilaterally or bilaterally, were observed in seven patients (88%), all of whom had femoral hernia. Of the five patients with bowel obstruction at presentation, four were determined not to require resection after assessment of the intestinal viability by laparoscopy. There was one case of conversion to a two-stage hernia repair performed to avoid mesh contamination: addition of mini-laparotomy, followed by extraction of the gangrenous intestine for resection and anastomosis with simple peritoneal closure of the hernia defect in the first stage, and a Kugel hernia repair in the second stage. There was no incidence of postoperative morbidity, mortality, or recurrence. Conclusions Because TAPP allows assessment of not only the entire groin area bilaterally but also simultaneous assessment of the viability of the incarcerated intestine with a minimum abdominal wall defect, we believe that it is an adequate approach to the treatment of both occult and acutely incarcerated OH. Two-stage hernia repair is technically feasible in patients requiring resection of the incarcerated intestine.ArticleWORLD JOURNAL OF SURGERY. 35(10):2323-2327 (2011)journal articl
Neurodevelopment of children exposed in utero to treatment of maternal malignancy
Cancer is the second most common cause of death during the reproductive years, complicating approximately 1/1000 pregnancies. The occurrence of cancer during gestation is likely to increase as a result of a woman's tendency to delay childbearing. Improved diagnostic techniques for malignancies increases detection of cancer during pregnancy. Malignant conditions during gestation are believed to be associated with an increase in poor perinatal and fetal outcomes that are often due to maternal treatment. Physicians should weigh the benefits of treatment against the risks of fetal exposure. To date, most reports have focused on morphologic observations made very close to the time of delivery with little data collected on children's long-term neurodevelopment following in utero exposure to malignancy and treatment. Because the brain differentiates throughout pregnancy and in early postnatal life, damage may occur even after first trimester exposure. The possible delayed effects of treatment on a child's neurological, intellectual and behavioural functioning have never been systematically evaluated. The goal of this report was to summarize all related issues into one review to facilitate both practitioners' and patients' access to known data on fetal risks and safety. Β© 2001 Cancer Research Campaign http://www.bjcancer.co
The meaning and measurement of implementation climate
<p>Abstract</p> <p>Background</p> <p>Climate has a long history in organizational studies, but few theoretical models integrate the complex effects of climate during innovation implementation. In 1996, a theoretical model was proposed that organizations could develop a positive climate for implementation by making use of various policies and practices that promote organizational members' means, motives, and opportunities for innovation use. The model proposes that implementation climate--or the extent to which organizational members perceive that innovation use is expected, supported, and rewarded--is positively associated with implementation effectiveness. The implementation climate construct holds significant promise for advancing scientific knowledge about the organizational determinants of innovation implementation. However, the construct has not received sufficient scholarly attention, despite numerous citations in the scientific literature. In this article, we clarify the meaning of implementation climate, discuss several measurement issues, and propose guidelines for empirical study.</p> <p>Discussion</p> <p>Implementation climate differs from constructs such as organizational climate, culture, or context in two important respects: first, it has a strategic focus (implementation), and second, it is innovation-specific. Measuring implementation climate is challenging because the construct operates at the organizational level, but requires the collection of multi-dimensional perceptual data from many expected innovation users within an organization. In order to avoid problems with construct validity, assessments of within-group agreement of implementation climate measures must be carefully considered. Implementation climate implies a high degree of within-group agreement in climate perceptions. However, researchers might find it useful to distinguish implementation climate level (the average of implementation climate perceptions) from implementation climate strength (the variability of implementation climate perceptions). It is important to recognize that the implementation climate construct applies most readily to innovations that require collective, coordinated behavior change by many organizational members both for successful implementation and for realization of anticipated benefits. For innovations that do not possess these attributes, individual-level theories of behavior change could be more useful in explaining implementation effectiveness.</p> <p>Summary</p> <p>This construct has considerable value in implementation science, however, further debate and development is necessary to refine and distinguish the construct for empirical use.</p
Population Genomics of Parallel Adaptation in Threespine Stickleback using Sequenced RAD Tags
Next-generation sequencing technology provides novel opportunities for gathering genome-scale sequence data in natural populations, laying the empirical foundation for the evolving field of population genomics. Here we conducted a genome scan of nucleotide diversity and differentiation in natural populations of threespine stickleback (Gasterosteus aculeatus). We used Illumina-sequenced RAD tags to identify and type over 45,000 single nucleotide polymorphisms (SNPs) in each of 100 individuals from two oceanic and three freshwater populations. Overall estimates of genetic diversity and differentiation among populations confirm the biogeographic hypothesis that large panmictic oceanic populations have repeatedly given rise to phenotypically divergent freshwater populations. Genomic regions exhibiting signatures of both balancing and divergent selection were remarkably consistent across multiple, independently derived populations, indicating that replicate parallel phenotypic evolution in stickleback may be occurring through extensive, parallel genetic evolution at a genome-wide scale. Some of these genomic regions co-localize with previously identified QTL for stickleback phenotypic variation identified using laboratory mapping crosses. In addition, we have identified several novel regions showing parallel differentiation across independent populations. Annotation of these regions revealed numerous genes that are candidates for stickleback phenotypic evolution and will form the basis of future genetic analyses in this and other organisms. This study represents the first high-density SNPβbased genome scan of genetic diversity and differentiation for populations of threespine stickleback in the wild. These data illustrate the complementary nature of laboratory crosses and population genomic scans by confirming the adaptive significance of previously identified genomic regions, elucidating the particular evolutionary and demographic history of such regions in natural populations, and identifying new genomic regions and candidate genes of evolutionary significance
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