Bifid Throats for Axion Monodromy Inflation

We construct a simple explicit local geometry providing a `bifid throat' for 5-brane axion monodromy. A bifid throat is a throat that splits into two daughter throats in the IR, containing a homologous 2-cycle family reaching down into each daughter throat. Our example consists of a deformed $\mathbb{Z}_3\times\mathbb{Z}_2$ orbifold of the conifold, which provides us with an explicit holographic dual of the bifid throat including D3-branes and fractional 5-branes at the toric singularities of our setup. Having the holographic description in terms of the dual gauge theory allows us to address the effect of 5-brane-antibrane pair backreaction including the warping effects. This leads to the size of the backreaction being small and controllable after imposing proper normalization of the inflaton potential and hence the warping scales.Comment: 35 pages, 22 figures. JHEP accepted version with typos corrected and references adde

Mars surface science requirements and plan

The requirements for obtaining geological, geochemical, geophysical, and meteorological data on the surface of Mars associated with manned landings were analyzed. Specific instruments were identified and their mass and power requirements estimated. A total of 1 to 5 metric tons, not including masses of drill rigs and surface vehicles, will need to be landed. Power associated only with the scientific instruments is estimated to be 1 to 2 kWe. Requirements for surface rover vehicles were defined and typical exploration traverses during which instruments will be positioned and rock and subsurface core samples obtained were suggested

Gun Carrying Among Adolescents

Outdoor education is a promising educational field that can support indoor education and provide benefits beyond the evidentknowledge. Outdoor and indoor education together can formulate the ground for an integrated learning. In Greece, like manycountries, outdoor education and its potential contribution to the learning process have not been clearly and intentionally testedyet, even though the country tends to follow a progressive educational philosophy. This research focuses on the subject ofmathematics and explores the connections between the existing philosophy and practices of mathematics education in Greece andoutdoor education theory and practice. Following the method of content analysis, the connections were identified through theexistence of basic outdoor education concepts in the mathematics textbooks of the last three grades of primary school. Althoughthe expectations, because of the lack of personal experiences, could not be high, the application of outdoor education seems to befar from impossible in Greece. It could rather flourish even without any changes in the books, when its potentialities are realizedby the teachers

Atypical miRNA expression in temporal cortex associated with dysregulation of immune, cell cycle, and other pathways in autism spectrum disorders.

BackgroundAutism spectrum disorders (ASDs) likely involve dysregulation of multiple genes related to brain function and development. Abnormalities in individual regulatory small non-coding RNA (sncRNA), including microRNA (miRNA), could have profound effects upon multiple functional pathways. We assessed whether a brain region associated with core social impairments in ASD, the superior temporal sulcus (STS), would evidence greater transcriptional dysregulation of sncRNA than adjacent, yet functionally distinct, primary auditory cortex (PAC).MethodsWe measured sncRNA expression levels in 34 samples of postmortem brain from STS and PAC to find differentially expressed sncRNA in ASD compared with control cases. For differentially expressed miRNA, we further analyzed their predicted mRNA targets and carried out functional over-representation analysis of KEGG pathways to examine their functional significance and to compare our findings to reported alterations in ASD gene expression.ResultsTwo mature miRNAs (miR-4753-5p and miR-1) were differentially expressed in ASD relative to control in STS and four (miR-664-3p, miR-4709-3p, miR-4742-3p, and miR-297) in PAC. In both regions, miRNA were functionally related to various nervous system, cell cycle, and canonical signaling pathways, including PI3K-Akt signaling, previously implicated in ASD. Immune pathways were only disrupted in STS. snoRNA and pre-miRNA were also differentially expressed in ASD brain.ConclusionsAlterations in sncRNA may underlie dysregulation of molecular pathways implicated in autism. sncRNA transcriptional abnormalities in ASD were apparent in STS and in PAC, a brain region not directly associated with core behavioral impairments. Disruption of miRNA in immune pathways, frequently implicated in ASD, was unique to STS

Form finding nodal connections in grid structure

Nodes for grid structures are often manufactured in a rather material intensive and inefficient way, increasing the weight of the structure and thus the load. Recent development of additive manufacturing techniques, have resulted in a rising interest in large-scale metal 3D printing. Topology optimization has become the obvious companion in the design of structural parts for 3D printing, and rightfully so. The technique is demonstrably able to provide material efficient solutions and is well suited for a manufacturing technique with few formal restrictions. However, from a designer’s perspective one could argue that topology optimization have some limitations. Like other “automated processes”, it tends to take over and does not leave much room for other form drivers. This paper presents an alternative method for designing material efficient nodes in grid structures that builds on the conventional form-finding techniques, usually applied to create minimal surface tensile structures or gravity shell like structures. The technique works by modelling the node as a hollow shell with a mesh, applying a set of tensile forces derived from the structural action from elements adjacent to the node (where compression is converted to tension) and running a form finding simulation. After the simulation, the shell is then thickened and analysed for the real load case (which consider both tension and compression) using FE-analysis. The benefit of such technique is that the designer has control over the topology of the design which enables more creative control and free exploration of a range of design variations. The form finding is done using dynamic relaxation and introduces spline elements with bending capability to control deviation from the pure spring network solution