Interlayer Registry Determines the Sliding Potential of Layered Metal Dichalcogenides: The case of 2H-MoS2

We provide a simple and intuitive explanation for the interlayer sliding energy landscape of metal dichalcogenides. Based on the recently introduced registry index (RI) concept, we define a purely geometrical parameter which quantifies the degree of interlayer commensurability in the layered phase of molybdenum disulphide (2HMoS2). A direct relation between the sliding energy landscape and the corresponding interlayer registry surface of 2H-MoS2 is discovered thus marking the registry index as a computationally efficient means for studying the tribology of complex nanoscale material interfaces in the wearless friction regime.Comment: 13 pages, 7 figure

Money, Power, and Monetary Regimes

Money, in this paper, is defined as a power relationship of a specific kind, a stratified social debt relationship, measured in a unit of account determined by some authority. A brief historical examination reveals its evolving nature in the process of social provisioning. Money not only predates markets and real exchange as understood in mainstream economics but also emerges as a social mechanism of distribution, usually by some authority of power (be it an ancient religious authority, a king, a colonial power, a modern nation state, or a monetary union). Money, it can be said, is a 'creature of the state' that has played a key role in the transfer of real resources between parties and the distribution of economic surplus. In modern capitalist economies, the currency is also a simple public monopoly. As long as money has existed, someone has tried to tamper with its value. A history of counterfeiting, as well as that of independence from colonial and economic rule, is another way of telling the history of 'money as a creature of the state.' This historical understanding of the origins and nature of money illuminates the economic possibilities under different institutional monetary arrangements in the modern world. We consider the so-called modern 'sovereign' and 'nonsovereign' monetary regimes (including freely floating currencies, currency pegs, currency boards, dollarized nations, and monetary unions) to examine the available policy space in each case for pursuing domestic policy objectives

Auxin transport through non-hair cells sustains root-hair development.

The plant hormone auxin controls root epidermal cell development in a concentration-dependent manner. Root hairs are produced on a subset of epidermal cells as they increase in distance from the root tip. Auxin is required for their initiation and continued growth, but little is known about its distribution in this region of the root. Contrary to the expectation that hair cells might require active auxin influx to ensure auxin supply, we did not detect the auxin-influx transporter AUX1 in root-hair cells. A high level of AUX1 expression was detected in adjacent non-hair cell files. Non-hair cells were necessary to achieve wild-type root-hair length, although an auxin response was not required in these cells. Three-dimensional modelling of auxin flow in the root tip suggests that AUX1-dependent transport through non-hair cells maintains an auxin supply to developing hair cells as they increase in distance from the root tip, and sustains root-hair outgrowth. Experimental data support the hypothesis that instead of moving uniformly though the epidermal cell layer, auxin is mainly transported through canals that extend longitudinally into the tissue

Pedestal bifurcation and resonant field penetration at the threshold of edge-localized mode suppression in the DIII-D tokamak

Rapid bifurcations in the plasma response to slowly varying n=2 magnetic fields are observed as the plasma transitions into and out of edge-localized mode (ELM) suppression. The rapid transition to ELM suppression is characterized by an increase in the toroidal rotation and a reduction in the electron pressure gradient at the top of the pedestal that reduces the perpendicular electron flow there to near zero. These events occur simultaneously with an increase in the inner-wall magnetic response. These observations are consistent with strong resonant field penetration of n=2 fields at the onset of ELM suppression, based on extended MHD simulations using measured plasma profiles. Spontaneous transitions into (and out of) ELM suppression with a static applied n=2 field indicate competing mechanisms of screening and penetration of resonant fields near threshold conditions. Magnetic measurements reveal evidence for the unlocking and rotation of tearinglike structures as the plasma transitions out of ELM suppression.This work is supported by the U.S. Department of Energy under Awards No. DE-FC02-04ER54698, No. DE-AC02-09CH11466, No. DE-FG02-07ER54917, No. DE-FG02-89ER53296, No. DE-FG02-08ER54999, No. DE-FG02-08ER54984, No. DE-AC05-00OR22725, No. DE-FG02-86ER53218, and No. DE-FG02- 92ER54139

The effect of Aloe ferox Mill. in the treatment of loperamide-induced constipation in Wistar rats

<p>Abstract</p> <p>Background</p> <p>Constipation is the most common gastrointestinal complaint all over the world and it is a risk factor of colorectal cancer. In this study, the efficacy of aqueous leaf extract of <it>Aloe </it><it>ferox </it>Mill. was studied against loperamide-induced constipation in Wistar rats.</p> <p>Methods</p> <p>Constipation was induced by oral administration of loperamide (3 mg/kg body weight) while the control rats received normal saline. The constipated rats were treated with 50, 100 and 200 mg/kg body weight/day of the extract for 7 days during which the feeding characteristics, body weight, fecal properties and gastrointestinal transit ratio were monitored.</p> <p>Results</p> <p>The extract improved intestinal motility, increased fecal volume and normalized body weight in the constipated rats, which are indications of laxative property of the herb with the 200 mg/kg body weight of the extract showing the best efficacy.</p> <p>Conclusion</p> <p>The effect of the extract compares favourably well with senokot, a standard laxative drug. These findings have therefore, lent scientific credence to the folkloric use of the herb as a laxative agent by the people of the Eastern Cape of South Africa.</p

Requirement of argininosuccinate lyase for systemic nitric oxide production

Nitric oxide (NO) is crucial in diverse physiological and pathological processes. We show that a hypomorphic mouse model of argininosuccinate lyase (encoded by Asl) deficiency has a distinct phenotype of multiorgan dysfunction and NO deficiency. Loss of Asl in both humans and mice leads to reduced NO synthesis, owing to both decreased endogenous arginine synthesis and an impaired ability to use extracellular arginine for NO production. Administration of nitrite, which can be converted into NO in vivo, rescued the manifestations of NO deficiency in hypomorphic Asl mice, and a nitric oxide synthase (NOS)-independent NO donor restored NO-dependent vascular reactivity in humans with ASL deficiency. Mechanistic studies showed that ASL has a structural function in addition to its catalytic activity, by which it contributes to the formation of a multiprotein complex required for NO production. Our data demonstrate a previously unappreciated role for ASL in NOS function and NO homeostasis. Hence, ASL may serve as a target for manipulating NO production in experimental models, as well as for the treatment of NO-related diseases

On the Centrality of Redemption: Linking the State and Credit Theories of Money Through a Financial Approach to Money

The paper presents a financial approach to monetary analysis that links the credit and state theories of money. A premise of the functional approach to money is that "money is what money does." In this approach, monetary and mercantile mechanics are conflated, which leads to the conclusion that unconvertible monetary instruments are worthless. The financial approach to money strictly separates the two mechanics and argues that major monetary disruptions occurred when the two were conflated. Monetary instruments have always been promissory notes. As such, their financial characteristics are central to their value and liquidity. One of the main financial requirements of any monetary instrument is that it be redeemable at any time. As long as this is the case, the fair value of an unconvertible monetary instrument is its face value. While the functional approach does not recognize the centrality of redemption, the paper shows that redemption plays a critical role in the state and credit views of money. Payments due to issuer and/or convertibility on demand are central to the possibility of par circulation. The paper shows that this has major implications for monetary analysis, both in terms of understanding monetary history and in terms of performing monetary analysis

Discovery of Western European R1b1a2 Y Chromosome Variants in 1000 Genomes Project Data: An Online Community Approach

The authors have used an online community approach, and tools that were readily available via the Internet, to discover genealogically and therefore phylogenetically relevant Y-chromosome polymorphisms within core haplogroup R1b1a2-L11/S127 (rs9786076). Presented here is the analysis of 135 unrelated L11 derived samples from the 1000 Genomes Project. We were able to discover new variants and build a much more complex phylogenetic relationship for L11 sub-clades. Many of the variants were further validated using PCR amplification and Sanger sequencing. The identification of these new variants will help further the understanding of population history including patrilineal migrations in Western and Central Europe where R1b1a2 is the most frequent haplogroup. The fine-grained phylogenetic tree we present here will also help to refine historical genetic dating studies. Our findings demonstrate the power of citizen science for analysis of whole genome sequence data