Black ribbons (Autumn mix)

7' vinyl single and digital download

Influence of kaolinite/carbon black hybridization on combustion and thermal decomposition behaviors of NR composites

A series of NR composites filled with modified kaolinite (MK), carbon black (CB) and the hybrid fillercontained MK and CB, were prepared by melt blending. The microstructure, combustion and thermaldecomposition behaviors of NR composites were characterized by TEM, XRD, infrared spectroscopy, conecalorimeter test (CCT) and thermal-gravimetric analysis (TG). The results show that the filler hybridizationcan improve the dispensability and shape of the kaolinite sheets in the rubber matrix and change theinterface bond between kaolinite particles and rubber molecules. NR-3 filled by 10 phr MK and 40 phr CBhas the lowest heat release rate (HRR), mass loss rate (MLR), total heat release (THR), smoke productionrate (SPR) and the highest char residue among all the NR composites. Therefore, the hybridization ofthe carbon black particles with the kaolinite particles can effectively improve the thermal stability andcombustion properties of NR composites.

Second harmonic generation and multiphoton microscopic detection of collagen without the need for species specific antibodies

High-resolution, high-contrast, three-dimensional images of live cell and tissue architecture can be obtained using second harmonic generation (SHG), which comprises non-absorptive frequency changes in an excitation laser line. SHG does not require any exogenous antibody or fluorophore labeling, and can generate images from unstained sections of several key endogenous biomolecules, in a wide variety of species and from different types of processed tissue. Here, we examined normal control human skin sections and human burn scar tissues using SHG on a multi-photon microscope (MPM). Examination and comparison of normal human skin and burn scar tissue demonstrated a clear arrangement of fibers in the dermis, similar to dermal collagen fiber signals. Fluorescence-staining confirmed the MPM-SHG collagen colocalization with antibody staining for dermal collagen type-I but not fibronectin or elastin. Furthermore, we were able to detect collagen MPM-SHG signal in human frozen sections as well as in unstained paraffin embedded tissue sections that were then compared with hematoxylin and eosin staining in the identical sections. This same approach was also successful in localizing collagen in porcine and ovine skin samples, and may be particularly important when species-specific antibodies may not be available. Collectively, our results demonstrate that MPM SHG-detection is a useful tool for high resolution examination of collagen architecture in both normal and wounded human, porcine and ovine dermal tissue.

Scanning electron microscopic study of microstructure of Gala apples during hot air drying

Microscopic changes occur in plant food materials during drying significantly influence the macroscopic properties and quality factors of the dried food materials. It is very critical to study microstructure to understand the underlying cellular mechanisms to improve performance of the food drying techniques. However, there is very limited research conducted on such microstructural changes of plant food material during drying. In this work, Gala apple parenchyma tissue samples were studied using a scanning electron microscope for gradual microstructural changes as affected by temperature, time and moisture content during hot air drying at two drying temperatures: 57 ℃ and 70 ℃. For fresh samples, the average cellular parameter values were; cell area: 20000 μm2, ferret diameter: 160 μm, perimeter: 600 μm, roundness: 0.76, elongation: 1.45 and compactness: 0.84. During drying, a higher degree of cell shrinkage was observed with cell wall warping and increase in intercellular space. However, no significant cell wall breakage was observed. The overall reduction of cell area, ferret diameter and perimeter were about 60%, 40% and 30%. The cell roundness and elongation showed overall increments of about 5% and the compactness remained unchanged. Throughout the drying cycle, cellular deformations were mainly influenced by the moisture content. During the initial and intermediate stages of drying, cellular deformations were also positively influenced by the drying temperature and the effect was reversed at the final stages of drying which provides clues for case hardening of the material.

Voltammetric, spectroscopic, and microscopic investigations of electrocrystallized forms of semiconducting AgTCNQ (TCNQ=7,7,8,8-tetracyanoquinodimethane) exhibiting different morphologies and colors

Chemically synthesized AgTCNQ exists in two forms that differ in their morphologies (needles and microcrystals) and colors (red and blue). It is now shown that both forms exhibit essentially indistinguishable X-ray diffraction, spectroscopic, and thermochemical data, implying that they are not separate phases, as implied in some literature. Electrochemical reduction of TCNQ((MeCN)) in the presence of Ag+((MeCN)) generates both red and blue AgTCNQ. On glassy carbon, platinum, or indium tin oxide electrodes and at relatively positive deposition potentials, slow growth of high aspect ratio, red needle AgTCNQ crystals occurs. After longer times and at more negative deposition potentials, blue microcrystalline AgTCNQ thin films are favored. Blue AgTCNQ is postulated to be generated via reduction of a Ag+\[(TCNQ(center dot-))(TCNQ)]((MeCN)) intermediate. At even more negative potentials, Ag-(metal) formation inhibits further growth of AgTCNQ. On a gold electrode, Ag-(metal)) deposition occurs at more positive potentials than on the other electrode materials examined. However, surface plasmon resonance data indicate (hat a small potential region is available between the stripping of Ag-(metal)) and the oxidation of TCNQ(center dot-)(MeCN) back to TCNQ(MeCN) where AgTCNQ may form. AgTCNQ in both the red and blue forms also can be prepared electrochemically on a TCNQ((s)) modified electrode in -0.1 M AgNO3(aq) where deposition of Ag(m,,,I) onto the TCNQ((s)) crystals allows a charge transfer process to occur. However, the morphology formed in this solid-solid phase transformation is more difficult to control.

Treating the whole not the hole : necessary coupling of technologies for diabetic foot ulcer treatment

Highlights • Diabetic foot ulcers (DFUs) are a major complication of diabetes. • We describe the development of next-generation technologies for DFU repair. • We highlight the modest success of growth factor-, scaffold-, and cell-based DFU therapies. • We rationalize that combination therapies will be necessary to enable effective and reliable DFU repair.

The Black-tailed Antechinus, Antechinus arktos sp. nov.: a new species of carnivorous marsupial from montane regions of the Tweed Volcano caldera, eastern Australia

We describe a new species of dasyurid marsupial within the genus Antechinus that was previously known as a northern outlier of Dusky Antechinus (A. swainsonii). The Black-tailed Antechinus, Antechinus arktos sp. nov., is known only from areas of high altitude and high rainfall on the Tweed Volcano caldera of far south-east Queensland and north-east New South Wales, Australia. Antechinus arktos formerly sheltered under the taxonomic umbrella of A. swainsonii mimetes, the widespread mainland form of Dusky Antechinus. With the benefit of genetic hindsight, some striking morphological differences are herein resolved: A. s. mimetes is more uniformly deep brown-black to grizzled grey-brown from head to rump, with brownish (clove brown—raw umber) hair on the upper surface of the hindfoot and tail, whereas A. arktos is more vibrantly coloured, with a marked change from greyish-brown head to orange-brown rump, fuscous black on the upper surface of the hindfoot and dense, short fur on the evenly black tail. Further, A. arktos has marked orange-brown fur on the upper and lower eyelid, cheek and in front of the ear and very long guard hairs all over the body; these characters are more subtle in A. s. mimetes. There are striking genetic differences between the two species: at mtDNA, A. s. mimetes from north-east New South Wales is 10% divergent to A. arktos from its type locality at Springbrook NP, Queensland. In contrast, the Ebor A. s. mimetes clades closely with conspecifics from ACT and Victoria. A. arktos skulls are strikingly different to all subspecies of A. swainsonii. A. arktos are markedly larger than A. s. mimetes and A. s. swainsonii (Tasmania) for a range of craniodental measures. Antechinus arktos were historically found at a few proximate mountainous sites in south-east Queensland, and have only recently been recorded from or near the type locality. Even there, the species is likely in low abundance. The Black-tailed Antechinus has plausibly been detrimentally affected by climate change in recent decades, and will be at further risk with increasing warming trends.

Active security in multiparty computation over black-box groups

Most previous work on unconditionally secure multiparty computation has focused on computing over a finite field (or ring). Multiparty computation over other algebraic structures has not received much attention, but is an interesting topic whose study may provide new and improved tools for certain applications. At CRYPTO 2007, Desmedt et al introduced a construction for a passive-secure multiparty multiplication protocol for black-box groups, reducing it to a certain graph coloring problem, leaving as an open problem to achieve security against active attacks. We present the first n-party protocol for unconditionally secure multiparty computation over a black-box group which is secure under an active attack model, tolerating any adversary structure Δ satisfying the Q 3 property (in which no union of three subsets from Δ covers the whole player set), which is known to be necessary for achieving security in the active setting. Our protocol uses Maurer’s Verifiable Secret Sharing (VSS) but preserves the essential simplicity of the graph-based approach of Desmedt et al, which avoids each shareholder having to rerun the full VSS protocol after each local computation. A corollary of our result is a new active-secure protocol for general multiparty computation of an arbitrary Boolean circuit.

Book Review: "Language, literacy, and pedagogy in postindustrial societies : the case of black academic underachievement"

Mocombe and Tomlin’s Language, Literacy, and Pedagogy in Postindustrial Societies: The Case of Black Academic Underachievement is part of the Routledge Research in Education series. The purpose of the work is to set out a theoretical framework for understanding the black/white academic achievement gap in the age of globalisation and post-industrialism. The authors use each chapter to develop an explanation for the persistent black/white academic achievement gap, by theorising that the gap is an epiphenomenon of global capitalist, post-industrial structures, reinforced by education as an apparatus of the system...

A light and electron microscopic study of NADPH-diaphorase-,calretinin- and parvalbumin-containing neurons in the rat nucleus accumbens

The rat nucleus accumbens contains medium-sized, spiny projection neurons and intrinsic, local circuit neurons, or interneurons. Sub-classes of interneurons, revealed by calretinin (CR) or parvalbumin (PV) immunoreactivity or reduced nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase histochemistry, were compared in the nucleus accumbens core, shell and rostral pole. CR, PV and NADPH-diaphorase-containing neurons are shown to form three non-co-localising populations in these three areas. No significant differences in neuronal population densities were found between the subterritories. NADPH-diaphorase-containing neurons could be further separated morphologically into three sub-groups, but CR- and PV-immunoreactive neurons form homogeneous populations. Ultrastructurally, NADPH-diaphorase-, CR- and PV-containing neurons in the nucleus accumbens all possess nuclear indentations. These are deeper and fewer in neurons immunoreactive for PV than in CR- and NADPH-diaphorase-containing neurons. CR-immunoreactive boutons form asymmetrical and symmetrical synaptic specialisations on spines, dendrites and somata, while PV-immunoreactive boutons make only symmetrical synaptic specialisations. Both CR- and PV-immunoreactive boutons form symmetrical synaptic specialisations with medium-sized spiny neurons and contact other CR- and PV-immunoreactive somata, respectively. A novel non-carcinogenic substrate for the peroxidase reaction (Vector Slate Grey, SG) was found to be characteristically electron-dense and may be distinguishable from the diaminobenzidine reaction product. We conclude that the three markers used in this study are localised in distinct populations of nucleus accumbens interneurons. Our studies of their synaptic connections contribute to an increased understanding of the intrinsic circuitry of this area.

Differences in physical activity between black and white girls living in rural and urban areas

This study examined the relationship of race and rural/urban setting to physical, behavioral, psychosocial, and environmental factors associated with physical activity. Subjects included 1,668 eighth-grade girls from 31 middle schools: 933 from urban settings, and 735 from rural settings. Forty-six percent of urban girls and 59% of rural girls were Black. One-way and two-way ANOVAs with school as a covariate were used to analyze the data. Results indicated that most differences were associated with race rather than setting. Black girls were less active than White girls, reporting significantly fewer 30-minute blocks of both vigorous and moderate-to-vigorous physical activity. Black girls also spent more time watching television, and had higher BMIs and greater prevalence of overweight than White girls. However, enjoyment of physical education and family involvement in physical activity were greater among Black girls titan White girls. Rural White girls and urban Black girls had more favorable attitudes toward physical activity. Access to sports equipment, perceived safety of neighborhood, and physical activity self-efficacy were higher in White girls than Black girls.

The effect of microscopic texture on the direct plasma surface passivation of Si solar cells

Textured silicon surfaces are widely used in manufacturing of solar cells due to increasing the light absorption probability and also the antireflection properties. However, these Si surfaces have a high density of surface defects that need to be passivated. In this study, the effect of the microscopic surface texture on the plasma surface passivation of solar cells is investigated. The movement of 105 H+ ions in the texture-modified plasma sheath is studied by Monte Carlo numerical simulation. The hydrogen ions are driven by the combined electric field of the plasma sheath and the textured surface. The ion dynamics is simulated, and the relative ion distribution over the textured substrate is presented. This distribution can be used to interpret the quality of the Si dangling bonds saturation and consequently, the direct plasma surface passivation.

Microscopic ion fluxes in plasma-aided nanofabrication of ordered carbon nanotip structures

Three-dimensional topography of microscopic ion fluxes in the reactive hydrocarbon-based plasma-aided nanofabrication of ordered arrays of vertically aligned single-crystalline carbon nanotip microemitter structures is simulated by using a Monte Carlo technique. The individual ion trajectories are computed by integrating the ion equations of motion in the electrostatic field created by a biased nanostructured substrate. It is shown that the ion flux focusing onto carbon nanotips is more efficient under the conditions of low potential drop Us across the near-substrate plasma sheath. Under low- Us conditions, the ion current density onto the surface of individual nanotips is higher for higher-aspect-ratio nanotips and can exceed the mean ion current density onto the entire nanopattern in up to approximately five times. This effect becomes less pronounced with increasing the substrate bias, with the mean relative enhancement of the ion current density ξi not exceeding ∼1.7. The value of ξi is higher in denser plasmas and behaves differently with the electron temperature Te depending on the substrate bias. When the substrate bias is low, ξi decreases with Te, with the opposite tendency under higher- Us conditions. The results are relevant to the plasma-enhanced chemical-vapor deposition of ordered large-area nanopatterns of vertically aligned carbon nanotips, nanofibers, and nanopyramidal microemitter structures for flat-panel display applications. © 2005 American Institute of Physics.

On secure multi-party computation in black-box groups

We study the natural problem of secure n-party computation (in the passive, computationally unbounded attack model) of the n-product function f G (x 1,...,x n ) = x 1 ·x 2 ⋯ x n in an arbitrary finite group (G,·), where the input of party P i is x i  ∈ G for i = 1,...,n. For flexibility, we are interested in protocols for f G which require only black-box access to the group G (i.e. the only computations performed by players in the protocol are a group operation, a group inverse, or sampling a uniformly random group element). Our results are as follows. First, on the negative side, we show that if (G,·) is non-abelian and n ≥ 4, then no ⌈n/2⌉-private protocol for computing f G exists. Second, on the positive side, we initiate an approach for construction of black-box protocols for f G based on k-of-k threshold secret sharing schemes, which are efficiently implementable over any black-box group G. We reduce the problem of constructing such protocols to a combinatorial colouring problem in planar graphs. We then give two constructions for such graph colourings. Our first colouring construction gives a protocol with optimal collusion resistance t < n/2, but has exponential communication complexity O(n*2t+1^2/t) group elements (this construction easily extends to general adversary structures). Our second probabilistic colouring construction gives a protocol with (close to optimal) collusion resistance t < n/μ for a graph-related constant μ ≤ 2.948, and has efficient communication complexity O(n*t^2) group elements. Furthermore, we believe that our results can be improved by further study of the associated combinatorial problems.

A large proportion of asymptomatic Plasmodium infections with low and sub-microscopic parasite densities in the low transmission setting of Temotu Province, Solomon Islands : challenges for malaria diagnostics in an elimination setting

Background Many countries are scaling up malaria interventions towards elimination. This transition changes demands on malaria diagnostics from diagnosing ill patients to detecting parasites in all carriers including asymptomatic infections and infections with low parasite densities. Detection methods suitable to local malaria epidemiology must be selected prior to transitioning a malaria control programme to elimination. A baseline malaria survey conducted in Temotu Province, Solomon Islands in late 2008, as the first step in a provincial malaria elimination programme, provided malaria epidemiology data and an opportunity to assess how well different diagnostic methods performed in this setting. Methods During the survey, 9,491 blood samples were collected and examined by microscopy for Plasmodium species and density, with a subset also examined by polymerase chain reaction (PCR) and rapid diagnostic tests (RDTs). The performances of these diagnostic methods were compared. Results A total of 256 samples were positive by microscopy, giving a point prevalence of 2.7%. The species distribution was 17.5% Plasmodium falciparum and 82.4% Plasmodium vivax. In this low transmission setting, only 17.8% of the P. falciparum and 2.9% of P. vivax infected subjects were febrile (≥38°C) at the time of the survey. A significant proportion of infections detected by microscopy, 40% and 65.6% for P. falciparum and P. vivax respectively, had parasite density below 100/μL. There was an age correlation for the proportion of parasite density below 100/μL for P. vivax infections, but not for P. falciparum infections. PCR detected substantially more infections than microscopy (point prevalence of 8.71%), indicating a large number of subjects had sub-microscopic parasitemia. The concordance between PCR and microscopy in detecting single species was greater for P. vivax (135/162) compared to P. falciparum (36/118). The malaria RDT detected the 12 microscopy and PCR positive P. falciparum, but failed to detect 12/13 microscopy and PCR positive P. vivax infections. Conclusion Asymptomatic malaria infections and infections with low and sub-microscopic parasite densities are highly prevalent in Temotu province where malaria transmission is low. This presents a challenge for elimination since the large proportion of the parasite reservoir will not be detected by standard active and passive case detection. Therefore effective mass screening and treatment campaigns will most likely need more sensitive assays such as a field deployable molecular based assay.