445 research outputs found
Anti-damping spin transfer torque through epitaxial Nickel oxide
We prepare the high quality epitaxial
MgO(001)[100]/Pt(001)[100]/NiO(001)[100]/FeNi/SiO2 films to investigate the
spin transport in the NiO antiferromagnetic insulator. The ferromagnetic
resonance measurements of the FeNi under a spin current injection from the Pt
by the spin Hall effect revealed the change of the ferromagnetic resonance
linewidth depending on the amount of the spin current injection. The results
can be interpreted that there is an angular momentum transfer through the NiO.
A high efficient angular momentum transfer we observed in the epitaxial NiO can
be attributed to the well-defined orientation of the antiferromagnetic moments
and the spin quantization axis of the injected spin current
Quantification of PERF 15 mRNA in Tissue Sections from Rat Testes
We previously conducted basic research to quantify in situ hybridization (ISH) signals in rat testes. In this experimental model, we selected ribosomal RNA (rRNA) as the hybridizable RNA in paraffin sections, since it allowed us to easily analyze ISH signals expressed with digoxygenin (DIG)-labeled probes quantitatively through “posterization” of the images. We applied this method to analyze the quantification of transcript, PERF 15 mRNA. PERF 15 is expressed specifically in the testes and localized in the rigid cytoskeletal structure of the sperm head, and has been considered to be involved in the apoptotic process of spermatogenic cells. Quantification of the signals may help to clarify the detailed function of PERF 15. We further analyzed the signals concomitant with a confocal laser scanning microscope. The peak of PERF 15 mRNA expression was found in diplotene spermatocytes, and the amount of PERF 15 mRNA was greatest in late pachytene and diplotene spermatocytes and early spermatids, followed by early pachytene spermatocytes, and then late spermatids. PERF 15 may be involved in the events leading to meiotic division, in which apoptosis is also involved. The present study may help to determine the concentration of mRNA in tissue sections
3D imaging by serial block face scanning electron microscopy for materials science using ultramicrotomy
AbstractMechanical serial block face scanning electron microscopy (SBFSEM) has emerged as a means of obtaining three dimensional (3D) electron images over volumes much larger than possible by focused ion beam (FIB) serial sectioning and at higher spatial resolution than achievable with conventional X-ray computed tomography (CT). Such high resolution 3D electron images can be employed for precisely determining the shape, volume fraction, distribution and connectivity of important microstructural features. While soft (fixed or frozen) biological samples are particularly well suited for nanoscale sectioning using an ultramicrotome, the technique can also produce excellent 3D images at electron microscope resolution in a time and resource-efficient manner for engineering materials. Currently, a lack of appreciation of the capabilities of ultramicrotomy and the operational challenges associated with minimising artefacts for different materials is limiting its wider application to engineering materials. Consequently, this paper outlines the current state of the art for SBFSEM examining in detail how damage is introduced during slicing and highlighting strategies for minimising such damage. A particular focus of the study is the acquisition of 3D images for a variety of metallic and coated systems
A noise-driven attractor switching device
Problems with artificial neural networks originate from their deterministic
nature and inevitable prior learnings, resulting in inadequate adaptability
against unpredictable, abrupt environmental change. Here we show that a
stochastically excitable threshold unit can be utilized by these systems to
partially overcome the environmental change. Using an excitable threshold
system, attractors were created that represent quasi-equilibrium states into
which a system settles until disrupted by environmental change. Furthermore,
noise-driven attractor stabilization and switching were embodied by inhibitory
connections. Noise works as a power source to stabilize and switch attractors,
and endows the system with hysteresis behavior that resembles that of
stereopsis and binocular rivalry in the human visual cortex. A canonical model
of the ring network with inhibitory connections composed of class 1 neurons
also shows properties that are similar to the simple threshold system.Comment: 9 pages, 2 tables, and 6 figures. will appear in Phy.Rev.E, vol.79,
issue
Ferro-quadrupolar ordering in PrTiAl
Origin of the non-magnetic phase transition in PrTiAl, reported
earlier in the macroscopic study, has been asserted microscopically using
elastic and inelastic neutron scattering techniques. It has been shown
spectroscopically that the crystalline-electric-field ground state is a
non-magnetic doublet, whereas the excited states are two triplets
( and ) and a singlet (). The diffraction
experiment under external magnetic field shows that the non-magnetic transition
is indeed ferro-quadrupolar ordering, which takes place as a consequence of
cooperative removal of the ground-state-doublet degeneracy. It is therefore
concluded that PrTiAl is another rare example of Pr compounds
exhibiting non-magnetic quadrupolar order.Comment: 7pages, 7 figure, and 1 table, submitted to PR
Social preparations towards community-based approach to stock enhancement in Sagay Marine Reserve, Philippines
Stock enhancement involves a set of management approaches which include the release of hatchery-produced aquatic organisms to enhance or restore fisheries. Stock enhancement of various species has a long history in developed countries and it showed that releases have the potential to yield substantial benefits for various fishery stakeholders. While the biological objectives of stock enhancement were often successfully achieved in most of these enhancement initiatives, some results showed that actual social gains in terms of yields, distribution of benefits and institutional sustainability are often inconclusive. The high cost of stocking accrues to the government which means these are supported by public funds. Meanwhile, benefits are dissipated across various stakeholders, some of them did not at all contribute and participate in the stocking program. In such government-initiated and publicly-funded stock enhancement programs, the lack of sense of stewardship among direct fishery stakeholders was observed to have contributed to a vicious cycle of excessive extraction of fishery resources for individual economic benefits.
Developing countries such as the Philippines would be confronted by budgetary limitations if it has to adopt the stocking strategies applied in developed countries. Thus, with reference to the success of co-management approaches for managing fishery resources in the Philippines, a community-based strategy for enhancement of fishery stocks was explored. SEAFDEC/AQD, with support from the Government of Japan Trust Fund, initiated a community-based approach to stock enhancement in Molocaboc, an island barangay or village within the Sagay Marine Reserve (SMR). The initiative aims to ensure that its goals and strategies are within the social milieu of local stakeholders, i.e. fisherfolks are without financial assets to contribute or pay for the enhancement of the fishery and stock enhancement is often not a priority approach to address fishery resource depletion for most local governments. However, the social assets of fishing communities could be explored to implement stock enhancement. This paper describes the social preparation executed from 2007 to 2011 in order to orient a fishing community such as Molocaboc towards a successful enhancement of overfished species. Initially, the project focused on donkey s ear abalone Haliotis asinina to provide an example for other species. Abalone or kapinan in the vernacular is one of the over-extracted fishery resources in Sagay City. It is one of the high-priced catch among fishers in coastal communities in the Philippines. High buying prices compared with other fish catch motivated small-scale fishers to target abalones and caused its overfishing
Correction to "Influence of Dust and Black Carbon on the Snow Albedo in the NASA Goddard Earth Observing System Version 5 Land Surface Model"
The website information describing the forcing meteorological data used for the land surface model (LSM) simulation, which were observed at an Automated Meteorological Station CAWS) at the Sapporo District Meteorological Observatory maintained by the Japan Meteorological Agency (JMA), was missing from the text. The 1-hourly data were obtained from the website of Kisyoutoukeijouhou (Information for available JMA-observed meteorological data in the past) on the website of JMA (in Japanese) (available at: http://www.jma.go.jpijmaimenulreport.html). The measurement height information of 59.5 m for the anemometer at the Sapporo Observatory was also obtained from the website of JMA (in Japanese) (available at: http://www.jma.go.jp/jma/menu/report.html). In addition, the converted 10-m wind speed, based on the AWS/JMA data, was further converted to a 2-m wind speed prior to its use with the land model as a usual treatment of off-line Catchment simulation. Please ignore the ice absorption data on the website mentioned in paragraph [15] which was not used for our calculations (but the data on the website was mostly the same as the estimated ice absorption coefficients by the following method because they partially used the same data by Warren [1984]). We calculated the ice absorption coefficients with the method mentioned in the same paragraph, for which some of the refractive index data by Warren [1984] were used and then interpolated between wavelengths, and also mentioned in paragraph [20] for the visible (VIS) and near-infrared (NIR) ranges. The optical data we used were interpolated between wavelengths as necessary
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