2,033 research outputs found
PLSS: A Projected Linear Systems Solver
We propose iterative projection methods for solving square or rectangular
consistent linear systems . Projection methods use sketching matrices
(possibly randomized) to generate a sequence of small projected subproblems,
but even the smaller systems can be costly. We develop a process that appends
one column each iteration to the sketching matrix and that converges in a
finite number of iterations independent of whether the sketch is random or
deterministic. In general, our process generates orthogonal updates to the
approximate solution . By choosing the sketch to be the set of all
previous residuals, we obtain a simple recursive update and convergence in at
most rank() iterations (in exact arithmetic). By choosing a sequence of
identity columns for the sketch, we develop a generalization of the Kaczmarz
method. In experiments on large sparse systems, our method (PLSS) with residual
sketches is competitive with LSQR, and our method with residual and identity
sketches compares favorably to state-of-the-art randomized methods
Anisotropic Assembly of Colloidal Nanoparticles: Exploiting Substrate Crystallinity
We show that the crystal structure of a substrate can be exploited to drive the anisotropic assembly of colloidal nanoparticles. Pentanethiol-passivated Au particles of approximately 2 nm diameter deposited from toluene onto hydrogen-passivated Si(111) surfaces form linear assemblies (rods) with a narrow width distribution. The rod orientations mirror the substrate symmetry, with a high degree of alignment along principal crystallographic axes of the Si(111) surface. There is a strong preference for
anisotropic growth with rod widths substantially more tightly distributed than lengths. Entropic trapping of nanoparticles provides a plausible explanation for the formation of the anisotropic assemblies we observe
A review of the recent developments of Green Banking in Bangladesh
This paper aims to explore the emergence of ‘Green Banking’ in Bangladesh, with a focus on the role of financial regulation and regulators in greening the financial sector. It also examines the contribution and involvement of banks and non-bank financial institutions in promoting green economic transition. The study is based on the review of secondary data collected from various sources, such as quarterly reports, annual reports, websites of the central bank of Bangladesh, and other commercial banks and non-bank financial institutions as well as various articles, and newspapers reports on green banking in Bangladesh. The collected data is reviewed using descriptive statistics. The research results reveal that the central bank of Bangladesh played a major role in greening the financial system of the country by implementing various green policies and regulatory measures. Although Bangladesh is still far behind the developed countries in terms of environmental performance, the country has made a remarkable progress in initiating and expanding green banking practices, infrastructure development, and accelerating green growth in recent years
Ecology of the Aedes australis (Erichson) 1842 Complex (Diptera: Culicidae) in Australia and New Zealand
ABSTRACT Most populations of Ae. australis developed their first egg batch without a bloodmeal (autogeny), but the proportion of females that were autogenous was altered by environmental conditions. Low rearing temperatures were more favourable than high temperatures for autogenous egg development, when combined with a rich protein larval diet. Neither an adult carbohydrate meal nor mating were necessary for maximum autogenous egg production. Of five Tasmania collections examined, the proponion of autogenous females amongst the different populations ranged from 100% to 0%. In the autogenous Sydney, NSW, population, the addition of a blood-meal did not increase egg production in the first gonotrophic cycle
High-threshold mechanosensitive ion channels blocked by a novel conopeptide mediate pressure-evoked pain
Little is known about the molecular basis of somatosensory mechanotransduction in mammals. We screened a library of peptide toxins for effects on mechanically activated currents in cultured dorsal root ganglion neurons. One conopeptide analogue, termed NMB-1 for noxious mechanosensation blocker 1, selectively inhibits (IC50 1 µM) sustained mechanically activated currents in a subset of sensory neurons. Biotinylated NMB-1 retains activity and binds selectively to peripherin-positive nociceptive sensory neurons. The selectivity of NMB-1 was confirmed by the fact that it has no inhibitory effects on voltage-gated sodium and calcium channels, or ligand-gated channels such as acid-sensing ion channels or TRPA1 channels. Conversely, the tarantula toxin, GsMTx-4, which inhibits stretch-activated ion channels, had no effects on mechanically activated currents in sensory neurons. In behavioral assays, NMB-1 inhibits responses only to high intensity, painful mechanical stimulation and has no effects on low intensity mechanical stimulation or thermosensation. Unexpectedly, NMB-1 was found to also be an inhibitor of rapid FM1-43 loading (a measure of mechanotransduction) in cochlear hair cells. These data demonstrate that pharmacologically distinct channels respond to distinct types of mechanical stimuli and suggest that mechanically activated sustained currents underlie noxious mechanosensation. NMB-1 thus provides a novel diagnostic tool for the molecular definition of channels involved in hearing and pressure-evoked pain
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