1,883 research outputs found
A compilation of games, devices, poems, and stories to be used for teaching arithmetic
Thesis (Ed.M.)--Boston University. Missing pages 119-120STATEMENT OF PROBLEM. The purpose of this study is
to compile and classify a variety of games, devices, poems,
stories, and other material, which teachers may use as aids in
the teaching of quantitative situations to children. These
games and devices have been compiled from numerous textbooks,
pamphlets, periodicals, methods books, teachers' manuals and courses of study. From this cumulative fund of information, only those games and devices meeting certain specific needs of children have been used.
SCOPE OF THE STUDY. The study will only be concerned
with games, devices, poems, and stories suitable for use in
Grades I to VI - with most emphasis placed on the primary grades' material - Grades I to III
Produksi Biji Bawang Merah Samosir Aksesi Simanindo Terhadap Konsentrasi GA3 Dan Lama Perendaman Di Dataran Tinggi Samosir
The aim of the research was to identify the effect of GA3 concentration and soaking period on the seed yield of shallot. Research was conducted at Hatoguan Village, Palipi Subdistrict, Samosir from February up to July 2014, carried out by using randomizes block design with two factors, replicated three times. The first factor was GA3 concentrations (50 ppm; 100 ppm; 150 ppm; 200 ppm; and 250 ppm) and the second was soaking period (30; 60; and 90 minutes). Parameters observed were the number of plant producing flowers per plot, the number of umbel per plot, seed weight per umbel, and seed weight per plot. The results showed that among all parameters observed, only the number of plants producing flowers per plot and seed weight per umbel were affected by GA3 concentration. The highest number of plants producing flowers and seed weight per umbel were produced by G4 (200 ppm GA3) i.e 10,780 plants (43,12 %) and 0,202 g respectively. Meanwhile, only seed weight per umbel was significantly affected by soaking period. The correlation between soaking period and seed weight per unbel showed positive linear regression
RdgB2 is required for dim-light input into intrinsically photosensitive retinal ganglion cells.
A subset of retinal ganglion cells is intrinsically photosensitive (ipRGCs) and contributes directly to the pupillary light reflex and circadian photoentrainment under bright-light conditions. ipRGCs are also indirectly activated by light through cellular circuits initiated in rods and cones. A mammalian homologue (RdgB2) of a phosphoinositide transfer/exchange protein that functions in Drosophila phototransduction is expressed in the retinal ganglion cell layer. This raised the possibility that RdgB2 might function in the intrinsic light response in ipRGCs, which depends on a cascade reminiscent of Drosophila phototransduction. Here we found that under high light intensities, RdgB2(-/-) mutant mice showed normal pupillary light responses and circadian photoentrainment. Consistent with this behavioral phenotype, the intrinsic light responses of ipRGCs in RdgB2(-/-) were indistinguishable from wild-type. In contrast, under low-light conditions, RdgB2(-/-) mutants displayed defects in both circadian photoentrainment and the pupillary light response. The RdgB2 protein was not expressed in ipRGCs but was in GABAergic amacrine cells, which provided inhibitory feedback onto bipolar cells. We propose that RdgB2 is required in a cellular circuit that transduces light input from rods to bipolar cells that are coupled to GABAergic amacrine cells and ultimately to ipRGCs, thereby enabling ipRGCs to respond to dim light
Impossibility to describe repulsion with contact interaction
Contact interactions always lead to attractive behaviour. Arguments are
presented to show why a repulsive interacting system, e.g. Bose gases, cannot
be described by contact interactions and corresponding treatments are possibly
obscured by the appearance of bound states. The usually used cut-offs are
identified as finite range parameters.Comment: 2 pages commen
Strongly residual coordinates over A[x]
For a domain A of characteristic zero, a polynomial f over A[x] is called a
strongly residual coordinate if f becomes a coordinate (over A) upon going
modulo x, and f becomes a coordinate upon inverting x. We study the question of
when a strongly residual coordinate is a coordinate, a question closely related
to the Dolgachev-Weisfeiler conjecture. It is known that all strongly residual
coordinates are coordinates for n=2 . We show that a large class of strongly
residual coordinates that are generated by elementaries upon inverting x are in
fact coordinates for arbitrary n, with a stronger result in the n=3 case. As an
application, we show that all Venereau-type polynomials are 1-stable
coordinates.Comment: 15 pages. Some minor clarifications and notational improvements from
the first versio
Functional Amyloid Formation within Mammalian Tissue
Amyloid is a generally insoluble, fibrous cross-β sheet protein aggregate. The process of amyloidogenesis is associated with a variety of neurodegenerative diseases including Alzheimer, Parkinson, and Huntington disease. We report the discovery of an unprecedented functional mammalian amyloid structure generated by the protein Pmel17. This discovery demonstrates that amyloid is a fundamental nonpathological protein fold utilized by organisms from bacteria to humans. We have found that Pmel17 amyloid templates and accelerates the covalent polymerization of reactive small molecules into melanin—a critically important biopolymer that protects against a broad range of cytotoxic insults including UV and oxidative damage. Pmel17 amyloid also appears to play a role in mitigating the toxicity associated with melanin formation by sequestering and minimizing diffusion of highly reactive, toxic melanin precursors out of the melanosome. Intracellular Pmel17 amyloidogenesis is carefully orchestrated by the secretory pathway, utilizing membrane sequestration and proteolytic steps to protect the cell from amyloid and amyloidogenic intermediates that can be toxic. While functional and pathological amyloid share similar structural features, critical differences in packaging and kinetics of assembly enable the usage of Pmel17 amyloid for normal function. The discovery of native Pmel17 amyloid in mammals provides key insight into the molecular basis of both melanin formation and amyloid pathology, and demonstrates that native amyloid (amyloidin) may be an ancient, evolutionarily conserved protein quaternary structure underpinning diverse pathways contributing to normal cell and tissue physiology
Collapse-and-revival dynamics of strongly laser-driven electrons
The relativistic quantum dynamics of an electron in an intense single-mode
quantized electromagnetic field is investigated with special emphasis on the
spin degree of freedom. In addition to fast spin oscillations at the laser
frequency, a second time scale is identified due to the intensity dependent
emissions and absorptions of field quanta. In analogy to the well-known
phenomenon in atoms at moderate laser intensity, we put forward the conditions
of collapses and revivals for the spin evolution in laser-driven electrons
starting at feasible W/cm.Comment: 18 pages, 4 figure
Extended morphometric analysis of neuronal cells with Minkowski valuations
Minkowski valuations provide a systematic framework for quantifying different
aspects of morphology. In this paper we apply vector- and tensor-valued
Minkowski valuations to neuronal cells from the cat's retina in order to
describe their morphological structure in a comprehensive way. We introduce the
framework of Minkowski valuations, discuss their implementation for neuronal
cells and show how they can discriminate between cells of different types.Comment: 14 pages, 18 postscript figure
- …