Spin diffusion of correlated two-spin states in a dielectric crystal

Reciprocal space measurements of spin diffusion in a single crystal of calcium fluoride (CaF$_2$) have been extended to dipolar ordered states. The experimental results for the component of the spin diffusion parallel with the external field are $D_{D}^{||}=29 \pm 3 \times 10^{-12}$ cm$^{2}$/s for the [001] direction and $D_{D}^{||}=33 \pm 4 \times 10^{-12}$ cm$^{2}$/s for the [111] direction. The diffusion rates for dipolar order are significantly faster than those for Zeeman order and are considerably faster than predicted by simple theoretical models. It is suggested that constructive interference in the transport of the two spin state is responsible for this enhancement. As expected the anisotropy in the diffusion rates is observed to be significantly less for dipolar order compared to the Zeeman case.Comment: 4 pages, 2 figures. Resubmitted to PRL - new figure added / discussion expande

Rapid methods of landslide hazard mapping : Fiji case study

A landslide hazard probability map can help planners (1) prepare for, and/or mitigate against, the effects of landsliding on communities and infrastructure, and (2) avoid or minimise the risks associated with new developments. The aims of the project were to establish, by means of studies in a few test areas, a generic method by which remote sensing and data analysis using a geographic information system (GIS) could provide a provisional landslide hazard zonation map. The provision of basic hazard information is an underpinning theme of the UN’s International Decade for Natural Disaster Reduction (IDNDR). It is an essential requirement for disaster preparedness and mitigation planning. This report forms part of BGS project 92/7 (R5554) ‘Rapid assessment of landslip hazards’ Carried out under the ODA/BGS Technology Development and Research Programme as part of the British Government’s provision of aid to developing countries. It provides a detailed technical account of work undertaken in a test area in Viti Levu in collaboration with Fiji Mineral Resources Department. The study represents a demonstration of a methodology that is applicable to many developing countries. The underlying principle is that relationships between past landsliding events, interpreted from remote sensing, and factors such as the geology, relief, soils etc provide the basis for modelling where future landslides are most likely to occur. This is achieved using a GIS by ‘weighting’ each class of each variable (e.g. each lithology ‘class’ of the variable ‘geology’) according to the proportion of landslides occurring within it compared to the regional average. Combinations of variables, produced by summing the weights in individual classes, provide ‘models’ of landslide probability. The approach is empirical but has the advantage of potentially being able to provide regional scale hazard maps over large areas quickly and cheaply; this is unlikely to be achieved using conventional ground-based geotechnical methods. In Fiji, landslides are usually triggered by intense rain storms commonly associated with tropical cyclones. However, the regional distribution of landslides has not been mapped nor is it known how far geology and landscape influence the location and severity of landsliding events. The report discusses the remote sensing and GIS methodology, and describes the results of the pilot study over an area of 713 km2 in south east Viti Levu. The landslide model uses geology, elevation, slope angle, slope aspect, soil type, and forest cover as inputs. The resulting provisional landslide hazard zonation map, divided into high, medium and low zones of landslide hazard probability, suggests that whilst rainfall is the immediate cause, others controls do exert a significant influence. It is recommended that consideration be given in Fiji to implementing the techniques as part of a national strategic plan for landslide hazard zonation mapping

Note and Comment

Judicial Reform in Michigan - The legislature which has been in regular session this year has enacted a measure enlarging the scope of judicial action in a way likely to add very greatly to the iusefulness of the courts. This law authorizes courts of record to make binding declarations of the rights of parties prior to the commission of a wrongful ac

Suspension and Measurement of Graphene and Bi2Se3 Atomic Membranes

Coupling high quality, suspended atomic membranes to specialized electrodes enables investigation of many novel phenomena, such as spin or Cooper pair transport in these two dimensional systems. However, many electrode materials are not stable in acids that are used to dissolve underlying substrates. Here we present a versatile and powerful multi-level lithographical technique to suspend atomic membranes, which can be applied to the vast majority of substrate, membrane and electrode materials. Using this technique, we fabricated suspended graphene devices with Al electrodes and mobility of 5500 cm^2/Vs. We also demonstrate, for the first time, fabrication and measurement of a free-standing thin Bi2Se3 membrane, which has low contact resistance to electrodes and a mobility of >~500 cm^2/Vs

A Screening tool for Identification of Victims of Commercial Sexual Exploitation of Children

Background: Commercial sexual exploitation of children (CSEC) and sex trafficking have only recently been recognized as problems by healthcare providers. Both UNICEF (2014) and the Institute of Medicine (2013) have stressed the need for systematic research to assist healthcare providers in the identification of victims. The aim of this poster is to describe initial findings relating to the development of a screening tool to identify CSEC victims. Methods: Twenty-seven sites nationwide (e.g., emergency departments and specialized clinics) participated in a study to validate a screening tool for identifying CSEC victims in an outpatient setting. The study was conducted under approval from the Institutional Review Board at Children’s Healthcare of Atlanta. Inclusion criteria for the study generally involved being an English-speaking adolescent aged 11-18 years. Results: Study enrollment is ongoing. Preliminary data for 210 youth were analyzed for this abstract. The sample was diverse with respect to age (M=14.59 years, SD=1.490 years) and ethnicity (56.4% Caucasian, 31.8% African American, 3.9% mixed race, and 7.8% Hispanic); the sample was predominantly female (92.8%). Of the 210 youth in the sample, 115(54.8%) have had sex. Of these 115 youth, 13(11.3%) have traded sex for money, drugs, or housing; 7(58.3%) of 12(10.4%) complied when asked by someone to have sex with another person; 8(61.5%) of 13(11.3%) performed sexual acts in public when propositioned; and 19(45.2%) of 42(36.5%) shared provocative photos when prompted. Medical providers flagged 14 youth (6.7% of total 210) as potential CSEC victims. Conclusions: The screening tool shows promise for effective identification of CSEC victims. This poster will present additional data and further quantitative analyses exploring the influences of sexual behavior, drug and alcohol use, and other factors on the risk of becoming a CSEC victim. Implications for researchers and clinicians will also be discussed

Fiabot!: design and evaluation of a mobile storytelling application for schools

This paper contributes to the ongoing debate about how digital technology can be integrated into the formal education system. Within a longitudinal research study, which lasted four years, we conducted an investigation on how mobile technology can support educational activities as defined by a school curriculum. Among the topics included in the school curriculum, we focused on the literary field and developed a Digital StoryTelling (DST) application, Fiabot!, to support this activity. Here, we describe the design of the application and how we evaluated its impact on educational activities. The application was designed and evaluated in two primary schools. The study had the objectives of exploring whether Fiabot! supports children in achieving educational objectives defined by the curriculum, how this effectively supports teachers, and to what extent children like using it for the creation and sharing of their stories. Our findings show that the application has a positive impact on curriculum enactment and effectively supports the related educational activities. Overall, Fiabot! wasdemonstrated to be very effective in stimulating children's discussion of a story's plot and characters. Thus, Fiabot! supported children not only in being creative but also in organizing their work and exploring a digital media opportunity. This resulted in the development of new skills and the better grounding of previously acquired knowledge, while teachers also had the opportunity to expand their teaching skills and get a taste of ICT's potential in education

A newly discovered subglacial lake in East Antarctica likely hosts a valuable sedimentary record of ice and climate change

The Princess Elizabeth Land sector of the East Antarctic Ice Sheet is a significant reservoir of grounded ice and is adjacent to regions that experienced great change during Quaternary glacial cycles and Pliocene warm episodes. The existence of an extensive subglacial water system in Princess Elizabeth Land (to date only inferred from satellite imagery) bears the potential to significantly impact the thermal and kinematic conditions of the overlying ice sheet. We confirm the existence of a major subglacial lake, herein referred to as Lake Snow Eagle (LSE), for the first time using recently acquired aerogeophysical data. We systematically investigated LSE’s geological characteristics and bathymetry from two-dimensional geophysical inversion models. The inversion results suggest that LSE is located along a compressional geologic boundary, which provides reference for future characterization of the geologic and tectonic context of this region. We estimate LSE to be ~42 km in length and 370 km2 in area, making it one of the largest subglacial lakes in Antarctica. Additionally, the airborne ice-penetrating radar observations and geophysical inversions reveal a layer of unconsolidated water-saturated sediment around and at the bottom of LSE, which—given the ultralow rates of sedimentation expected in such environments—may archive valuable records of paleoenvironmental changes and the early history of East Antarctic Ice Sheet evolution in Princess Elizabeth Land

Incidence and prognosis of vascular complications after percutaneous placement of left ventricular assist device

OBJECTIVE: Mechanical assist devices have found an increasingly important role in high-risk interventional cardiac procedures. The Impella (Abiomed Inc, Danvers, Mass) is a percutaneous left ventricular assist device inserted through the femoral artery under fluoroscopic guidance and positioned in the left ventricular cavity. This study was undertaken to assess the incidence of vascular complications and associated morbidity and mortality that can occur with Impella placement. METHODS: We used a prospective database to review patients who underwent placement of an Impella left ventricular assist device in our tertiary referral center from July 2010 to December 2013. Patient demographics, comorbidities, interventional complications, and 30-day mortality were recorded. RESULTS: The study included 90 patients (60% male). Mean age was 66 years (range, 17-97 years). Hypertension was found in 69% of the patients, 37% were diabetic, 57% had a history of tobacco abuse, and 65% had chronic renal insufficiency. The median preprocedure cardiac ejection fraction was 30%. Most (87%) had undergone coronary artery intervention. Cardiogenic shock was documented in 67 patients (74%). The Impella was placed for an average of 1 day (range, 0-5 days). At least one vascular complication occurred in 15 patients (17%). Acute limb ischemia occurred in 12 patients; of whom four required an amputation and six required open or endovascular surgery. Other complications included groin hematomas and one pseudoaneurysm. All-patient 30-day mortality was 50%, which was not significantly associated with vascular complications. Female sex and cardiogenic shock at the time of insertion were associated with vascular complications (P = .043 and P = .018, respectfully). CONCLUSIONS: Vascular complications are common with placement of the Impella percutaneous left ventricular assist device (17%) and are related to emergency procedures. Vascular complications in this high-risk patient population frequently lead to withdrawal of care. These data provide quality improvement targets for left ventricular assist device programs