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91.
T. V. Zakharchuk 《Scientific and Technical Information Processing》2012,39(4):208-214
This paper presents the results from a survey of the leading bibliographical scientists of the country on the problems of the formation and development of scientific schools in bibliographical science, the functions performed by them, and signs that are immanent to them. 相似文献
92.
Microfluidic devices have been established as useful platforms for cell culture for a broad range of applications, but challenges associated with controlling gradients of oxygen and other soluble factors and hemodynamic shear forces in small, confined channels have emerged. For instance, simple microfluidic constructs comprising a single cell culture compartment in a dynamic flow condition must handle tradeoffs between sustaining oxygen delivery and limiting hemodynamic shear forces imparted to the cells. These tradeoffs present significant difficulties in the culture of mesenchymal stem cells (MSCs), where shear is known to regulate signaling, proliferation, and expression. Several approaches designed to shield cells in microfluidic devices from excessive shear while maintaining sufficient oxygen concentrations and transport have been reported. Here we present the relationship between oxygen transport and shear in a "membrane bilayer" microfluidic device, in which soluble factors are delivered to a cell population by means of flow through a proximate channel separated from the culture channel by a membrane. We present an analytical model that describes the characteristics of this device and its ability to independently modulate oxygen delivery and hemodynamic shear imparted to the cultured cells. This bilayer configuration provides a more uniform oxygen concentration profile that is possible in a single-channel system, and it enables independent tuning of oxygen transport and shear parameters to meet requirements for MSCs and other cells known to be sensitive to hemodynamic shear stresses. 相似文献
93.
Robert T. Ivey 《Cataloging & classification quarterly》2013,51(5):464-482
Cataloging procedures have evolved in many academic research libraries over the past 10 years. Some predicted trends—outsourcing, original cataloging by paraprofessionals, more digital material—have been borne out. Others, such as a decline in the amount of material to catalog or in the number of professional catalogers, have not. Changes have been mostly procedural and have not affected the catalog itself. Recently, however, the emergence of powerful Internet search engines has allowed researchers to bypass the catalog. This has led some to question the wisdom of continuing it and others to vigorously defend current practice. In 2005–2007 this debate became especially heated, but a consensus appears to be emerging that although the character of the professional cataloger's job will continue to evolve over the next 5 to 10 years there will not be a revolution. The cataloger's basic skills will still be needed and the fundamental nature of cataloging will remain much as we know it. 相似文献
94.
This case study describes the efforts of librarians to integrate mobile devices, collaboration tools, and resources into a School of Medicine third-year pediatric clerkship. Additional class emphasis is on evidence-based searching and journal article evaluation and presentation. The class objectives ensure that students are comfortable with mobile devices and collaboration tools. Over the eight-year history of the course, student acceptance of the mobile devices used diminished as the devices aged, necessitating the evaluation and selection of new technologies. Collaboration tools and mobile applications employed in the course evolved to accommodate curriculum changes. 相似文献
95.
O.T. Kibwana Mitiku Haile Laurens vanVeldhuizen Ann Waters‐Bayer 《The Journal of Agricultural Education and Extension》2013,19(3):133-142
Abstract Promoting rural development in Africa involves learning to clap with two hands, that is to say, creating effective interaction between local knowledge and development initiatives, on the one hand, and the knowledge and initiatives of formal agricultural research and extension, on the other. Farmer innovators ‐men and women farmers who take their own initiative to change local agriculture ‐ are key allies in rural development, as shown by the experience of the ISWC programme in Africa. Focusing on Ethiopia and Tanzania, the authors describe how formal research and extension services are made aware of farmers’ innovative work and are encouraged to document the results, promote their spread, and support further development efforts by farmer innovators. A modified Participatory Technology Development (PTD) approach is thus emerging, which starts not with problem analysis but rather by linking up with local problem‐solving initiatives. While the learning process on this approach continues, dialogue has been initiated with policy‐makers with a view to incorporating the approach into regular government extension, research and training activities. 相似文献
96.
Depending on the kindness of strangers: current national data initiatives and developmental research 总被引:2,自引:0,他引:2
This article provides a brief review of current large-scale, longitudinal data collection initiatives focusing on children. These studies will be available for secondary data analyses in the twenty-first century. In addition to child outcome data, process-oriented information is being collected on child-parent interactions, quality of child care, elementary school teacher reports and classroom observations, accessibility and use of health, educational and social services, parental mental health, family violence, fathering, parental residence patterns, income and income sources, child support, employment patterns, and community characteristics. Several of these studies are randomized trials of the efficacy of early childhood intervention services and housing mobility programs. The usefulness of these efforts for exploring policy-relevant issues (child support enforcement, work requirements for welfare recipients, antipoverty strategies, housing subsidies and relocation, availability of child care, child-care subsidies) are discussed. 相似文献
97.
T. Gary Waller 《Learning & behavior》1974,2(4):298-304
Experiment I compared constant (CI), variable-between (VBI), and variable-within (WVI) irrelevant cues during an extradimensional (ED) shift discrimination. Performance was better for CI than for VBI and better for VBI than for VWI. Experiment II combined CI, VBI, and VWI cues with ED or intradimensional (ID) shifts. Irrelevant-cue conditions did not affect ID performance but did affect ED performance. The typical superiority of ID, as compared to ED, shifts was observed in the VWI condition but not in the CI condition. Implications for mediating-response (i.e., attention or observing-response) theories were indicated. 相似文献
98.
Kathryn L. Combs Sharon K. Gibson Jane Saly John T. Wendt 《Assessment & Evaluation in Higher Education》2008,33(1):87-102
Typical university‐wide course evaluations do not provide instructors with sufficient information on the effectiveness of their courses. This article describes a course assessment and enhancement model where student feedback can be used to improve courses and/or programs. The model employs an assessment tool that measures student perceptions of importance and their current competence in course‐specific learning objectives both pre‐ and post‐course. Information gained from this assessment enables course improvement over time and also allows for modification in delivery and/or content of the current course. This model is intended to augment traditional course evaluation mechanisms based on specific and actionable feedback on learning objectives. 相似文献
99.
Not all young children benefit from book exposure in preschool age. It is claimed that the ability to hold information in
mind (short-term memory), to ignore distraction (inhibition), and to focus attention and stay focused (sustained attention) may have a moderating effect on children’s reactions to the home literacy environment. In a group of 228 junior kindergarten
children with a native Dutch background, with a mean age of 54.29 months (SD = 2.12 months), we explored therefore the relationship
between book exposure, cognitive control and early literacy skills. Parents filled in a HLE questionnaire (book sharing frequency
and an author recognition checklist as indicator of parental leisure reading habits), and children completed several tests
in individual sessions with the researcher (a book-cover recognition test, PPVT, letter knowledge test, the subtests categories
and patterns of the SON, and cognitive control measures namely digit span of the KABC, a peg tapping task and sustained attention
of the ANT). Main findings were: (1) Children’s storybook knowledge mediated the relationship between home literacy environment
and literacy skills. (2) Both vocabulary and letter knowledge were predicted by book exposure. (3) Short-term memory predicted
vocabulary over and above book exposure. (4) None of the cognitive control mechanisms moderated the beneficial effects of
book exposure. 相似文献
100.
The Walsh operational matrix for performing integration and solving state equations is generalized to fractional calculus for investigating distributed systems. A new set of orthogonal functions is derived from Walsh functions. By using the new functions, the generalized Walsh operational matrices corresponding to √s, √(s2+ 1), e-s and e-√s etc. are established. Several distributed parameter problems are solved by the new approach. 相似文献