215,790 research outputs found
Modeling Building Block Interdependency
No full textThe Building-Block Hypothesis appeals to the notion of problem decomposition and the assembly of solutions from sub-solutions. Accordingly, there have been many varieties of GA test problems with a structure based on building-blocks. Many of these problems use deceptive fitness functions to model interdependency between the bits within a block. However, very few have any model of interdependency between building-blocks; those that do are not consistent in the type of interaction used intra-block and inter-block. This paper discusses the inadequacies of the various test problems in the literature and clarifies the concept of building-block interdependency. We formulate a principled model of hierarchical interdependency that can be applied through many levels in a consistent manner and introduce Hierarchical If-and-only-if (H-IFF) as a canonical example. We present some empirical results of GAs on H-IFF showing that if population diversity is maintained and linkage is tight then the GA is able to identify and manipulate building-blocks over many levels of assembly, as the Building-Block Hypothesis suggests
G. Vernon Block
No full text"Pte G. Vernon Block VX150404 7th Battalion [11] Platoon "B" Coy 1939 - 1945. Dulcie Block (wife)".Private G. Vernon Block VX150404. 7th Battalion, [11] Platoon, "B" Company 1939 - 1945. Dulcie Block (wife)
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The Synthesis, Self-Assembly and Self-Organisation of Polysilane Block Copolymers
No full textBlock copolymers containing polysilane blocks are unique in that the polysilane components possess electro-active properties and are readily photodegradable. This review will discuss and assess the two major approaches to the synthesis of polysilane block copolymers via pre-formed polymer chain coupling and living polymerisation techniques. The self-organisation of polysilane block copolymers and the morphologies adopted in thin films are reviewed. Amphiphilic polysilane-containing block copolymers self-assemble in solvents selective for one block and a number of examples are highlighted. The versatility of these materials is highlighted by recent significant applications including the preparation of hollow crosslinked micellar aggregates in aqueous solutions and in patterned thin film generation subsequently employed as templates for the growth of cell cultures and CaCO (3.
Solid-supported biomimetic membranes based on amphiphilic block copolymers
No full textPlanar artificial membranes based on amphiphilic block copolymers are of high interest due to their potential applications in catalysis, drug screening, sensing, etc. Such polymeric membranes can successfully mimic biological membranes, providing high robustness and stability, which makes them good candidates to be developed in direction of applications. Even though solid-supported polymer membranes have been already investigated to a certain extent, it is still an emerging area. This thesis presents a new generation of biomimetic solid-supported membranes and hybrid polymer-lipid materials, based on amphiphilic block copolymers: poly(dimethylsiloxane)-block-poly(2-methyl-2-oxazoline) (PDMS-b-PMOXA) and poly(ethylene glycol)-block-poly(γ-methyl-ε-caprolactone)-block-poly[(2-dimethylamino) ethyl methacrylate] (PEG-b-PMCL-b-PDMAEMA). The scope was preparation of stable solid-supported membranes and development of different strategies for insertion/attachment of biomolecules into such membranes. Block copolymers were firstly investigated in respect of behavior at the air-water interface. Deposition of the films on different solid supports (silica wafers, glass and gold slides) was achieved by performing transfers of Langmuir monolayers, which provide formation of defect-free films with good reproducibility. Further, deposited films were functionalized by introduction of membrane proteins and enzymes. To get the insights into morphology and thickness, the obtained systems were analyzed by surface-sensitive techniques, such as atomic force microscopy, ellipsometry, and contact angle measurements. Activity of inserted biomolecules was evaluated by electrical conductance measurements and activity assays. This thesis provides valuable impact in the preparation of membranes in a controllable and reproducible way. Furthermore, it presents different strategies for introduction of biomolecules into such systems, in order to obtain tailored functionality and properties. This work impact fundamental understanding and development of functional membranes. Such artificial membranes and hybrid materials can be further adapted for potential applications
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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The A/B alternating block versus the modified block in the middle school
No full texttextGiven that math achievement of eighth grade students has shown almost
no growth in the United States over a ten year period (National Assessment of
Educational Progress, United States Department of Education, 1995), this study
attempted to examine the effect a particular schedule design (A/B Alternating
Block and Modified Block) has on student math achievement as measured by a
standardized test (Texas Assessment of Academic Standards), student attendance
and drop out rate. The study attempted to determine whether middle school
students benefit academically, especially in the area of mathematics, from
instruction that is delivered in a Modified Block schedule format as compared to
instruction that is delivered in the A/B Alternating Block schedule design. Four
middle schools were selected according to comparable characteristics such as
campus demographics (ethnicity break down, socio-economic level, etc) and
schedule design in place. Data was collected on student math scores, attendance
and drop out rates.
Findings of the study indicate that overall and over time student
mathematics achievement was higher in schools where students received
instruction in the A/B Alternating Block scheduling format as compared to the
Modified Blocked schools. A closer observation revealed this was true especially
for White and Hispanic students. In reference to student attendance, the study
showed that overall student attendance was higher for those students enrolled in
schools with an A/B Alternating Block scheduling format as opposed to those
enrolled in Modified Blocked Schools. Thus, recommendations for practice would
include the continued implementation of the A/B Alternating Block schedule
design and the continued monitoring over time of math achievement by whole
group and by ethnic background. Finally, recommendations for further research
were made to conduct additional studies to further identify middle school
practices that will facilitate and provide for increased student achievement.Educational Administratio
A review of congenital heart block
No full textCongenital heart block is a rare disorder. It has an incidence of about 1 in 22,000 live
births. It may be associated with high mortality and morbidity. This should generate a
high index of suspicion for early diagnosis and aggressive therapy when appropriate.
The congenital heart block associated with neonatal lupus is considered a form of
passively acquired autoimmune disease in which maternal autoantibodies to the
intracellular ribonucleoproteins Ro (SS-A) and La (SS-B), cross the placenta and
injure the previously normal fetal heart. Women with serum titers of anti-Ro antibody
carry a 3% risk of having a child with neonatal lupus syndrome. Recurrence rates are
about 18%. We believe that serial echocardiograms should be acquired so that early
diagnosis is made and aggressive therapy administered, if signs of conduction
system disease such as PR interval prolongation by Doppler are found, so as to
optimize the outcome. Establishment of guidelines for therapy have been set
empirically, should signs of congenital heart block develop. Those patients whose
congenital heart block is associated with structural heart disease have a higher
morbidity and mortality, which is determined more by the underlying structural
congenital heart disease than it is by the need for a pacemaker per se.peer-reviewe
Adaptive nested trellis decoding for block codes.
No full textA new adaptive trellis decoding technique for block codes is proposed. The technique is based on an encoding technique which allows the design of almost all known linear codes together with their minimal trellises. The proposed adaptive trellis decoding technique allows the implementation of a single soft maximum likelihood trellis decoder for decoding of different codes. It has been shown that both the encoding and decoding techniques can be implemented with a low complexity and cost
Teachers' perceptions of the block schedule
No full textPlan BThis study was developed to investigate Menomonie High School teachers’ perceptions of the block schedule regarding modifications to departmental courses and services, advantages and disadvantages of the block schedule, and suggestions for modifications to the current block schedule. A researcher-developed questionnaire was sent via school mailbox to 66 faculty, with 28 returning the questionnaire and participating in the study. The findings indicate that modifications made to departmental courses and services included: the compacting of curriculum, the addition of terms to some courses, the inclusion of additional grade levels in some courses, and the creation of new courses. The advantages that were indicated included: longer class time allowed for more in-depth discovery type learning, varied teaching practices and activities, integration of content areas such as U.S. history/U.S. literature and speech/composition, fewer teacher preparations, longer preparation time, fewer courses for students to manage, less stress for teachers and students, improved relationships between students and teachers, and the creation of new elective course offerings. The disadvantages indicated included: less developmental time for learning, an increase in class sizes, some curriculum lost due to compacting, some departments could not service all student requests, some departments dropped electives to accommodate more sections of required courses, no safety net for failing students, difficulty of placing transfer students in the schedule, class balances unequally distributed, some students had difficulty maintaining attention for the longer period of time, retention loss during gaps between related courses, curriculum watered down due to necessary review time, difficulties for substitute teachers, no study halls for remediation, and student absences are more detrimental. Suggestions for modifying the current block schedule included: going to a trimester schedule with twelve or thirteen week grading terms and five sixty to sixty-five minute periods, increasing staff, modifying the block with skinnies, implementing an A/B block schedule, adding electives in all areas, keeping students with the same teacher for all terms of a course, building in more one on one time for students who are failing, and having three terms for lower level courses
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