2,886 research outputs found
Investigation of multilayer magnetic domain lattice file
A theoretical and experimental investigation determined that current accessed self structured bubble memory devices have the potential of meeting projected data density and speed requirements. Device concepts analyzed include multilayer ferrimagnetic devices where the top layer contains a domain structure which defines the data location and the second contains the data. Current aperture and permalloy assisted current propagation devices were evaluated. Based on the result of this work more detailed device research was initiated. Detailed theoretical and experimental studies indicate that the difference in strip and threshold between a single bubble in the control layer and a double bubble which would exist in both the control layer and data layer is adequate to allow for detection of data. Detailed detector designs were investigated
Investigation of multilayer magnetic domain lattice file
The feasibility of the self structured multilayered bubble domain memory as a mass memory medium for satellite applications is examined. Theoretical considerations of multilayer bubble supporting materials are presented, in addition to the experimental evaluation of current accessed circuitry for various memory functions. The design, fabrication, and test of four device designs is described, and a recommended memory storage area configuration is presented. Memory functions which were demonstrated include the current accessed propagation of bubble domains and stripe domains, pinning of stripe domain ends, generation of single and double bubbles, generation of arrays of coexisting strip and bubble domains in a single garnet layer, and demonstration of different values of the strip out field for single and double bubbles indicating adequate margins for data detection. All functions necessary to develop a multilayer self structured bubble memory device were demonstrated in individual experiments
Interannual and spatial variation in the population genetic composition of young-of-the-year Pacific Ocean Perch (Sebastes alutus) in Alaskan waters
Thesis (M.S.) University of Alaska Fairbanks, 2010We know little about the population structure of Gulf of Alaska (GOA) and Bering Sea rockfish, including Pacific ocean perch (POP, Sebastes alutus), and early life history information is sparse for many rockfish species. Young-of-the-year (YOY) POP were collected with surface trawls during surveys of juvenile salmon in the GOA and Bering Sea. These samples presented a unique opportunity to study POP genetics and life history. Fourteen microsatellite loci were used to characterize the genetic variation in POP collected in a total of 45 hauls over five years. The coincidence in timing and location of several collections between years allowed examination of both fine- and broad-scale geographic variation (within cohorts) as well as interannual (between cohorts) genetic variation. The geographic genetic structure of these collections was also compared to geographic structure of adult POP described in a previous study (Palof, 2008). As in the adult study, significant broad-scale geographic divergence was observed in YOY POP in the GOA. Fine-scale geographic divergence was also observed and may be the result of variable current regimes and oceanographic features at several locations. The limited amount of temporal variation observed seems to be the result of variable oceanography and fine-scale population structure rather than the influence of a sweepstakes effect. The relationship between genetic divergence and geographic separation is virtually identical in YOY and adult POP, which confirms that dispersal of POP is limited in all life stages and also demonstrates that most YOY are produced by adults that are located nearby.Introduction -- Materials and methods -- Sample collection -- Species identification -- Microsatellite analysis -- Data analysis -- Results -- Species identification -- Microsatellite data analysis -- Discussion and conclusions -- References -- Appendix
Summary of Toxicological Data for Aquatic Organisms of Illinois
The data presented in this report contain Information on toxicity testing performed on organisms that could be found In aquatic habitats in Illinois. To compile this information a thorough list of all aquatic organisms in Illinois was required. This was constructed through literature searches and personal communication with scientists who collect and identify Illinois aquatic specimens. Each species name was used to search a database which contained toxicity information on aquatic organisms. No toxicological Information was found for many Illinois species. For most organisms, all
available information retrieved from the database is presented. For species on which extensive toxicological research has been performed, data showing 96 hour LC50 or EC50
values and chronic testing values constitute the bulk of the records. In addition to records detailing toxicity values and experimental conditions, a list of tested chemical compounds and organisms is included.
Literature citing observations and identification of aquatic organisms within Illinois was the most valuable resource in compiling a list of Illinois aquatic species.
Staff of the Illinois Natural History Survey were helpful in recommending the most useful publications, making available their own field lists, and helping to update taxonomy and nomenclature from older reports. In particular we would like to acknowledge Don Webb, Larry Page, Warren Brigham, Mark Wetzel, Kevin Cummings, and Allison Brigham from the INHS Faunistics section and Michael Henebry from the section of Aquatic Biology.
To retrieve toxicity data on the aquatic organisms of Illinois, a Chemical Information System, Inc. database, AQUIRE
(Aquatic Information Retrieval System), was employed. AQUIRE contains data extracted from publications dealing with the toxic effects of chemical substances on aquatic organisms. Each Latin species name from the compiled Illinois list was used to search records in the database. If AQUIRE matched a record with the species name, the record was
stored. If there were an excessive number of matching records, the search was narrowed by specifying particular regimens and/or effective endpoint types. Ultimately a printout of the records pertaining to each organism was produced. The data contained In this report are duplications of the
AQUIRE records obtained for Illinois organisms. The taxonomy, habitat, and Illinois distribution is listed immediately preceding the AQUIRE records compiled for
each species. These records have been substantially reduced from their original size and are arranged by chemical compound
in alphabetical and/or numerical order.published or submitted for publicationis peer reviewe
"Learning Anew Is Easier Than Re-Learning". On The Difficulties Of A Group Accustomed To Education To Establish New (Media) Forms Of Participation
Das Internet bietet Lernenden vielfältige Möglichkeiten zur Wissensorganisation und -kommunikation in formalen und informellen Bildungskontexten. Bislang nutzen selbst bildungsaffine erwachsene Lerner diese unterstützenden Potenziale des Internets vielfach nur zurückhaltend. Dieser zögerliche Gebrauch zeigt sich auch dann, wenn die Implementierung virtuell vernetzter Applikationen in der Planung von den Lernenden von den Akteuren prinzipiell gefordert und begrüsst wird. Im Zentrum unseres Beitrags stehen mögliche Gründe und Bedingungen für diese vermeintlichen Widerstände und Problematiken bei der Integration des Partizipationsraums Internet für berufliche Lernprozesse. Grundlage für die Diskussion sind die Praxiserfahrungen und empirischen Ergebnisse einer explorativen Fallstudie mit einem ethisch beratenden Gremium. Die bisherige Bilanz des Projektvorhabens unterstreicht die Notwendigkeit, in diesem Kontext theoretische Konzepte zu Lernwiderständen, generationsspezifischen Aspekten, zur Mediendidaktik und zu Lerngewohnheiten und Transfer zu diskutieren. Die Ergebnisse belegen, dass digitale Lern- und Arbeitsformen unmittelbar an eingeschliffene Lernroutinen gebunden sind. Lernende benötigen Zeit, Raum, Anlässe und Struktur, um Handlungs- und Lernroutinen aufzubrechen und neue zu entwickeln. Nur so können digitale Partizipationsmöglichkeiten erfolgreich in den Arbeitsalltag integriert werden.The internet offers learners a wide range of possibilities for organising and communicating knowledge in formal and informal educational contexts. So far, even adult learners with an affinity for education have often been reluctant to use these supportive potentials of the internet. This hesitant use is also evident when the implementation of virtually networked applications in learner planning is in principle demanded and welcomed by stakeholders. The focus of our contribution is on possible reasons and conditions for these supposed resistances and problematic issues in the integration of the participatory space of the Internet for vocational learning processes. The basis for the discussion are the practical experiences and empirical results of an explorative case study with an ethical advisory board. The results of the project so far underline the need to discuss theoretical concepts on learning resistance, generation-specific aspects, media didactics and learning habits and transfer in this context. The results show that digital forms of learning and working are directly linked to ingrained learning routines. Learners need time, space, occasions and structure to break up action and learning routines and develop new ones. Only in this way can digital participation opportunities be successfully integrated into everyday working life
Integrating project based learning components into woodwork technology education curriculum at colleges of education in Nigeria
The main aim of this paper is to investigate project-based learning components suitable for integration into woodwork technology education curriculum (WTE) at Colleges of education (COE) in Nigeria. The study employed an intrinsic case study design. The population for the study comprised 12 respondents involving woodwork technology education lecturers and curriculum planners in north western Nigeria. Semi structured Interview protocol was the instrument used for collecting data for the study, while NVIVO 12 was used to analyse the qualitative data. Findings from the study revealed that the curriculum structure of WTE at COE does not include PoBL. The findings also revealed 21st century skills, inquiry and innovation, publicly presented product among the PoBL components suitable for integration into WTE curriculum at COE in Nigeria. Findings also revealed relevance of integrating PoBL in WTE curriculum, and equally showed from the responses of the participants that involvement of WTE students in investigation, collaboration grouping, and provision of adequate resource facilities as ways through which PoBL components can enhance student skill when integrated into WTE curriculum. Therefore, integrating components of PoBL into WTE curriculum affords students’ the opportunity to enhance their skills in WTE, and bridge the skill gap existing between WTE graduates and the industries
Steady-state charging of quantum batteries via dissipative ancillas
We investigate the steady-state charging process of a single-cell quantum
battery embedded in an N-cell star network of qubits, each interacting with a
fermion reservoir, collectively and individually in equilibrium and
non-equilibrium scenarios, respectively. We find an optimal steady-state
charging in both scenarios, which grows monotonically with the reservoirs'
chemical potential and chemical potential difference. Where the high base
temperature of the reservoirs has a destructive role in all parameter regimes.
We indicate that regardless of the strength of the non-equilibrium condition,
the high base chemical potential of the battery's corresponding reservoir can
significantly enhance the charging process. On the other hand, a weak coupling
strength can strongly suppress the charging. Consequently, our results could
counteract the detrimental effects of self-discharging and provide valuable
guidelines for enhancing the stable charging of open quantum batteries in the
absence of an external charging field.Comment: 5 pqages, 6 figure
MAD2L2 promotes open chromatin in embryonic stem cells and derepresses the Dppa3 locus.
The chromatin of naive embryonic stem cells (ESCs) has a largely open configuration, as evident by the lack of condensed heterochromatin and the hypomethylation of DNA. Several molecular mechanisms promoting this constellation were previously identified. Here we present evidence for an important epigenetic function of MAD2L2, a protein originally known for its role in DNA damage repair, and for its requirement in germ cell development. We demonstrate using super-resolution microscopy that numerous MAD2L2 microfoci are exclusively associated with euchromatin, similar to other factors of the DNA damage response. In the absence of MAD2L2 the amount of heterochromatin demarcated by H3K9me2 was significantly increased. Among the most strongly suppressed genes was Dppa3, an ESC- and germ-cell-specific gene regulating DNA methylation. In Mad2l2-deficient ESCs 5-methylcytosine levels were globally increased, while several imprinted genes became hypomethylated and transcriptionally activated. Our results emphasize the important function of MAD2L2 for the open chromatin configuration of ESCs
The impact of assessment techniques on the relationship between work-based learning and teamwork skills development
The purpose of this study was to investigate the mediating effect of assessment techniques on the relationship between work-based learning and teamwork skills development at technical colleges in Nigeria. The sample consists of 257 technical teachers. The CFA models were developed to obtain the Chi-square values, modification indices, and standardized estimates using AMOS. Structural Equation Modeling (SEM), employing AMOS version 22 was utilized to test the mediation effect and also the relationship between work-based learning and teamwork skills development among students of technical colleges. The findings of the study revealed that work-based learning has a direct significant negative relationship with teamwork skills development among students of technical colleges, while, it has a direct insignificant positive relationship with assessment techniques. However, when the mediation hypothesis was tested, the result indicates that assessment techniques have a significant positive indirect impact on teamwork skills development, that is, it fully mediates the relationship between work-based learning and teamwork skills development among students of technical colleges. This study implies to educators that there is a need to appropriately enforce the assessment techniques for effective development of teamwork skills among TVET students. It is therefore, confirmed that teamwork skills should be enhanced when work-based learning is used in collaboration with appropriate assessment techniques
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