Studies in the use of cloud type statistics in mission simulation

A study to further improve NASA's global cloud statistics for mission simulation is reported. Regional homogeneity in cloud types was examined; most of the original region boundaries defined for cloud cover amount in previous studies were supported by the statistics on cloud types and the number of cloud layers. Conditionality in cloud statistics was also examined with special emphasis on temporal and spatial dependencies, and cloud type interdependence. Temporal conditionality was found up to 12 hours, and spatial conditionality up to 200 miles; the diurnal cycle in convective cloudiness was clearly evident. As expected, the joint occurrence of different cloud types reflected the dynamic processes which form the clouds. Other phases of the study improved the cloud type statistics for several region and proposed a mission simulation scheme combining the 4-dimensional atmospheric model, sponsored by MSFC, with the global cloud model

Determinisitic Writing and Control of the Dark Exciton Spin using Short Single Optical Pulses

We demonstrate that the quantum dot-confined dark exciton forms a long-lived integer spin solid state qubit which can be deterministically on-demand initiated in a pure state by one optical pulse. Moreover, we show that this qubit can be fully controlled using short optical pulses, which are several orders of magnitude shorter than the life and coherence times of the qubit. Our demonstrations do not require an externally applied magnetic field and they establish that the quantum dot-confined dark exciton forms an excellent solid state matter qubit with some advantages over the half-integer spin qubits such as the confined electron and hole, separately. Since quantum dots are semiconductor nanostructures that allow integration of electronic and photonic components, the dark exciton may have important implications on implementations of quantum technologies consisting of semiconductor qubits.Comment: Added two authors, minor edits to figure captions, expanded discussion of dark exciton eigenstate

The Level-0 Muon Trigger for the LHCb Experiment

A very compact architecture has been developed for the first level Muon Trigger of the LHCb experiment that processes 40 millions of proton-proton collisions per second. For each collision, it receives 3.2 kBytes of data and it finds straight tracks within a 1.2 microseconds latency. The trigger implementation is massively parallel, pipelined and fully synchronous with the LHC clock. It relies on 248 high density Field Programable Gate arrays and on the massive use of multigigabit serial link transceivers embedded inside FPGAs.Comment: 33 pages, 16 figures, submitted to NIM

All-solid-state electrochromic reflectance device for emittance modulation in the far-infrared spectral region

All-solid-state electrochromic reflectance devices for thermal emittance modulation were designed for operation in the spectral region from mid- to far-infrared wavelengths (2–40 μm). All device constituent layers were grown by magnetron sputtering. The electrochromic (polycrystalline WO3), ion conductor (Ta2O5), and Li+ ion-storage layer (amorphous WO3), optimized for their infrared (IR) optical thicknesses, are sandwiched between a highly IR reflecting Al mirror, and a 90% IR transmissive Al grid top electrode, thereby meeting the requirements for a reversible Li+ ion insertion electrochromic device to operate within the 300 K blackbody emission range. Multicycle optical switching and emittance modulation is demonstrated. The measured change in emissivity of the device is to 20%

The Psychological Foundations of The Mediating Learning Support Assistant (MeLSA) Training Programme

It is estimated that a quarter of the mainstream school workforce in the UK are learning support staff. This is a substantial number of adults who have the potential to foster learning. This paper provides a brief summary regarding the impact of support staff on children and young people’s learning. It describes how the Mediating Learning Support Assistant (MeLSA) training programme was developed to meet a training gap identified in the literature. This paper also details the psychological theories and research evidence which provide the foundations for MeLSA and describes the format of the training programme, which consists of six days (mediating learning and mindset, thinking about thinking, memory and recall, mathematics, literacy, and implementation) followed by ongoing supervision. The aim of MeLSA is to ensure that learning support staff have the psychological and evidence-informed expertise to enable those with whom they are working to become competent and independent learners

Discovery of Very High-Energy Gamma-Ray Radiation from the BL Lac 1ES 0806+524

The high-frequency-peaked BL-Lacertae object \objectname{1ES 0806+524}, at redshift z=0.138, was observed in the very-high-energy (VHE) gamma-ray regime by VERITAS between November 2006 and April 2008. These data encompass the two-, and three-telescope commissioning phases, as well as observations with the full four-telescope array. \objectname{1ES 0806+524} is detected with a statistical significance of 6.3 standard deviations from 245 excess events. Little or no measurable variability on monthly time scales is found. The photon spectrum for the period November 2007 to April 2008 can be characterized by a power law with photon index $3.6 \pm 1.0_{\mathrm{stat}} \pm 0.3_{\mathrm{sys}}$ between $\sim$300 GeV and $\sim$700 GeV. The integral flux above 300 GeV is $(2.2\pm0.5_{\mathrm{stat}}\pm0.4_{\mathrm{sys}})\times10^{-12}\:\mathrm{cm}^{2}\:\mathrm{s}^{-1}$ which corresponds to 1.8% of the Crab Nebula flux. Non contemporaneous multiwavelength observations are combined with the VHE data to produce a broadband spectral energy distribution that can be reasonably described using a synchrotron-self Compton model.Comment: 14 pages, 4 figures, accepted to APJ

Genetic Analysis of the Interaction Between the Host Perennial Ryegrass and the Crown Rust Pathogen (\u3cem\u3ePuccinia Coronata\u3c/em\u3e F.SP. \u3cem\u3eLolii\u3c/em\u3e)

Crown rust (Puccinia coronata f.sp lolii) is the most important fungal pathogen of perennial ryegrass (L.perenne L.). The physiological effects associated with infection include reduction of water soluble carbohydrate (WSC) reserves, causing decreased dry matter yield, digestibility and palatability for herbivores reared for meat, milk and wool production. Phenotypic variability of rust-infection in perennial ryegrass is likely to be due to environmental effects, as well as the interaction of defence and resistance genes in the grass and virulence genes in the pathogen. Classical and molecular genetic marker-based studies have previously detected both qualitative and quantitative resistance, due respectively to major genes and quantitative trait loci (QTL). In addition, evidence for physiological race variation has been demonstrated for P. coronata f.sp. avenae, the causative organisms of crown rust in oat, and has been inferred for P. coronata f.sp. lolii. Evaluation of genotypic variation in both the host and pathogen is consequently important for the analysis of the interaction

Network development in biological gels: role in lymphatic vessel development

In this paper, we present a model that explains the prepatterning of lymphatic vessel morphology in collagen gels. This model is derived using the theory of two phase rubber material due to Flory and coworkers and it consists of two coupled fourth order partial differential equations describing the evolution of the collagen volume fraction, and the evolution of the proton concentration in a collagen implant; as described in experiments of Boardman and Swartz (Circ. Res. 92, 801–808, 2003). Using linear stability analysis, we find that above a critical level of proton concentration, spatial patterns form due to small perturbations in the initially uniform steady state. Using a long wavelength reduction, we can reduce the two coupled partial differential equations to one fourth order equation that is very similar to the Cahn–Hilliard equation; however, it has more complex nonlinearities and degeneracies. We present the results of numerical simulations and discuss the biological implications of our model