Imaging Carrier Inhomogeneities in Ambipolar Tellurene Field Effect Transistors

Developing van der Waals (vdW) homojunction devices requires materials with narrow bandgaps and simultaneously high hole and electron mobilities for bipolar transport, as well as methods to image and study spatial variations in carrier type and associated conductivity with nanometer spatial resolution. Here we demonstrate the general capability of near-field scanning microwave microscopy (SMM) to image and study the local carrier type and associated conductivity in operando by studying ambiploar field effect transistors (FETs) of the 1D vdW material tellurium in 2D form. To quantitatively understand electronic variations across the device, we produce nanometer resolved maps of the local carrier equivalence backgate voltage. We show that the global device conductivity minimum determined from transport measurements does not arise from uniform carrier neutrality, but rather from the continued coexistence of p-type regions at the device edge and n-type regions in the interior of our micron-scale devices. This work both underscores and addresses the need to image and understand spatial variations in the electronic properties of nanoscale devices.Comment: 15 pages, 4 figure

Community-based perceptions of emergency care in Kenya

Access to quality emergency services is an essential component of the human right to health, but barriers to emergency care are found throughout Africa and the wider world. Data to support the development of emergency care are essential to improve access to care and further infrastructure development. We undertook this study to understand the community\u27s emergency care needs and the barriers they face when trying to access care and to engage community members with developing high impact solutions to expand access to essential emergency services. To accomplish this, we used a qualitative research methodology to conduct 59 focus groups with 528 total Kenyan community member participants. Data were coded, aggregated, and analysed using the content analysis approach. Participants were uniformly selected from all eight of the historical Kenyan provinces (Central. Coast, Eastern, Nairobi, North Eastern, Nyanza, Rift Valley, and Western), with equal rural and urban community representation. We found that socioeconomic and cultural factors play a major role both in seeking and reaching emergency care. Community members in Kenya experience a wide range of medical emergencies and seem to understand their time-critical nature. They rely on one another for assistance in the face of substantial barriers to care: a lack of a structured system, resources, transportation, trained healthcare providers, and initial care on scene. The results of this study indicate the need for specific interventions to reduce barriers to access essential emergency services in Kenya. Access to emergency care can be improved by encouraging recognition and initial treatment of emergent illness in the community, strengthening the pre­-hospital care system, improving emergency care delivery at health facilities, and creating new policies at both county and national levels

Cool to warm white light emission from hybrid inorganic/organic light-emitting diodes

The synthesis and characterisation of two novel organic down-converting molecules is disclosed, together with their performance as functional colour-converters in combination with inorganic blue light-emitting diodes (LEDs). Each molecule contains two fluorene-triphenylamine arms, connected to either a benzothiadiazole or bisbenzothiadiazole core. These molecules have been selected on the basis that they are free from absorption bands in the green region of the visible spectrum to maximise their performance and offer improvements compared with previous BODIPY-containing analogues. The inorganic InGaN/GaN LED emits at 444 nm, overlying the absorption of each of the organic molecules. The combination of the blue (inorganic) and yellow (organic) emission is shown to produce reasonable quality, white light-emitting hybrid devices for both down-converter molecules. Cool to warm white light is achieved for both molecules by increasing the concentration. An optimum colour rendering index (CRI) value of 66 is obtained for the mono-benzothiadiazole molecule. Also a high blue-to-white efficacy (defined as white luminous flux (lm)/blue radiant flux (W)) of 368 lm/W is achieved, superseding the current phosphor converters of 200-300 lm/W. A comparison of these down-converting molecules to the older generation BODIPY-containing molecules is also provided

Analytical Models for Valence Fermions in Isotropic Traps

For isotropic confining Ioffe-Pritchard or TOP potentials, a valence fermion trapped with a closed core of other fermions can be described by an analytical effective one-particle model with a physical eigenspectrum. Related constructions exist for Paul and Penning traps. The analytical models arise from quantum-mechanical supersymmetry.Comment: accepted for publication in Physics Letters

Westgate Shootings: An Emergency Department Approach to a Mass-casualty Incident

At approximately 12:30 pm on Saturday September 21, 2013, armed assailants attacked the upscale Westgate shopping mall in the Westlands area of Nairobi, Kenya. Using the seven key Major Incident Medical Management and Support (MIMMS) principles, command, safety, communication, assessment, triage, treatment, and transport, the Aga Khan University Hospital, Nairobi (AKUH,N) emergency department (ED) successfully coordinated the reception and care of all the casualties brought to the hospital. This report describes the AKUH,N ED response to the first civilian mass-casualty shooting incident in Kenya, with the hope of informing the development and implementation of mass-casualty emergency preparedness plans by other EDs and hospitals in Kenya, appropriate for the local health care system. Wachira BW , Abdalla RO , Wallis LA . Westgate shootings: an emergency department approach to a mass-casualty incident. Prehosp Disaster Med. 2014;29(5):1-4

Multi-modal representation of effector modality in frontal cortex during rule switching.

We report a functional magnetic resonance imaging (fMRI) study which investigated whether brain areas involved in updating task rules within the frontal lobe of the cerebral cortex show activity related to the modality of motor response used in the task. Participants performed a rule switching task using different effector modalities. In some blocks participants responded with left/right button presses, whilst in other blocks left/right saccades were required. The color of a Cue event instructed a left or right response based upon a rule, followed by a Feedback which indicated whether the rule was to stay the same or "Flip" on the next trial. The findings revealed variation in the locus of activity within the ventrolateral frontal cortex dependent upon effector modality. Other frontal areas showed no significant difference in activity between response epochs but changed their pattern of connectivity with posterior cortical areas dependent upon response. Multivariate analysis revealed that the pattern of activity evoked by Flip rule Feedbacks within an apparently supra modal frontal region (dorsolateral frontal cortex) discriminated between response epochs. The results are consistent with the existence of multi-modal representations of stimulus-response (SR) rules within the frontal cerebral cortex

Writing in Britain and Ireland, c. 400 to c. 800

No abstract available

Governing irrigation renewal in rural Australia

Irrigation renewal schemes are taking place globally for water conservation and gains in agricultural productivity, as competition for water resources increases. The publically-funded renewal of irrigation infrastructure is a key platform of water reform in Australia’s Murray-Darling Basin; it is considered by some to be a policy that contradicts market-based approaches. In this Australian study, we examine an irrigation renewal scheme in northern Victoria resulting from a large investment by the State and Federal Governments. The long historical development of infrastructure and institutions for irrigation in the region led to technological lock-in and exposure to international terms of trade and climate change. From interviews with water professionals involved in the region, three key themes were identified through an adapted grounded theory approach: (1) a lack of an appropriate platform for fostering community involvement in what was a large-scale investment of public money; (2) issues in the way that water losses and savings were calculated; and (3) contradictions in policies for water buyback and irrigation renewal that lead to some irrigators being disadvantaged. To better understand the situation, we also applied a theoretical lens based on social learning. We conclude that the framing of a water ‘crisis’ was used to the benefit of some irrigators in attracting large-scale investment of public funds for irrigation renewal. The proposed solution, a technologically-driven irrigation renewal scheme, was implemented at a pace that didn’t match the planning horizons for many, leading many to exit from irrigated agriculture. Systemic insights for the design and implementation of irrigation renewal schemes internationally are highlighted

Review article: a comparison of glucagon-like peptides 1 and 2.

BACKGROUND: Recent advancements in understanding the roles and functions of glucagon-like peptide 1 (GLP-1) and 2 (GLP-2) have provided a basis for targeting these peptides in therapeutic strategies. AIM: To summarise the preclinical and clinical research supporting the discovery of new therapeutic molecules targeting GLP-1 and GLP-2. METHODS: This review is based on a comprehensive PubMed search, representing literature published during the past 30 years related to GLP-1 and GLP-2. RESULTS: Although produced and secreted together primarily from L cells of the intestine in response to ingestion of nutrients, GLP-1 and GLP-2 exhibit distinctive biological functions that are governed by the expression of their respective receptors, GLP-1R and GLP-2R. Through widespread expression in the pancreas, intestine, nervous tissue, et cetera, GLP-1Rs facilitates an incretin effect along with effects on appetite and satiety. GLP-1 analogues resistant to degradation by dipeptidyl peptidase-IV and inhibitors of dipeptidyl peptidase-IV have been developed to aid treatment of diabetes and obesity. The GLP-2R is expressed almost exclusively in the stomach and bowel. The most apparent role for GLP-2 is its promotion of growth and function of intestinal mucosa, which has been targeted for therapies that promote repair and adaptive growth. These are used as treatments for intestinal failure and related conditions. CONCLUSIONS: Our growing understanding of the biology and function of GLP-1, GLP-2 and corresponding receptors has fostered further discovery of fundamental biological function as well as new categories of potent therapeutic medicines

Effets des associations culturales sur la dynamique de population des principaux insectes ravageurs et la production en graines de Jatropha curcas L. au Sud-Bénin

Jatropha curcas est l’une des cultures proposées actuellement pour la production de biocarburant, ce qui pourrait entraver les cultures vivrières. Il a alors été suggéré d’associer jatropha avec les cultures vivrières. L’effet des associations Jatropha+Maïs (JM), Jatropha+Niébé (JN), Jatropha+Manioc (JMc) et Jatropha seul (Js) a été évalué sur les populations des ravageurs de J. curcas en champ à Ouinhi au Sud-Est du Bénin. Les sept espèces d’insectes ravageurs recensées sont : Denticera divisella, Aulocophora africana, Calidea dregei, Lagria vilosa, Apion sp., Stomphastis thraustica et Clavigralla tomentosicollis dont les plus importantes sont : Apion sp., A. africana et D. divisella. Le niveau de population des ravageurs a varié suivant l’association et le stade phénologique de jatropha. Les pourcentages de feuilles attaquées sont de 56,0 ± 3%; 52,0 ± 3%; 47,0 ± 3% et 44,0 ± 3%, respectivement pour JM, JN, JMc et Js. Les rendements en graines de jatropha sont de 9,77 ± 1,57 g ; 9,40 ± 1,71 g ; 4,63 ± 1,34 g ; 2,25 ± 1,10 g par plant, respectivement pour Js, JM, JN et JMc. En général, l’association culturale a affecté négativement la productivité du jatropha notamment dans les associations Jatropha+Manioc et Jatropha+Niébé qu’il importe de déconseiller.Mots clés: Biocarburant, pourghère, associations culturales, insectes ravageurs de jatropha, Denticera divisella, rendement de jatropha