Visible and near infrared spectroscopy in soil science

This chapter provides a review on the state of soil visible–near infrared (vis–NIR) spectroscopy. Our intention is for the review to serve as a source of up-to date information on the past and current role of vis–NIR spectroscopy in soil science. It should also provide critical discussion on issues surrounding the use of vis–NIR for soil analysis and on future directions. To this end, we describe the fundamentals of visible and infrared diffuse reflectance spectroscopy and spectroscopic multivariate calibrations. A review of the past and current role of vis–NIR spectroscopy in soil analysis is provided, focusing on important soil attributes such as soil organic matter (SOM), minerals, texture, nutrients, water, pH, and heavy metals. We then discuss the performance and generalization capacity of vis–NIR calibrations, with particular attention on sample pre-tratments, co-variations in data sets, and mathematical data preprocessing. Field analyses and strategies for the practical use of vis–NIR are considered. We conclude that the technique is useful to measure soil water and mineral composition and to derive robust calibrations for SOM and clay content. Many studies show that we also can predict properties such as pH and nutrients, although their robustness may be questioned. For future work we recommend that research should focus on: (i) moving forward with more theoretical calibrations, (ii) better understanding of the complexity of soil and the physical basis for soil reflection, and (iii) applications and the use of spectra for soil mapping and monitoring, and for making inferences about soils quality, fertility and function. To do this, research in soil spectroscopy needs to be more collaborative and strategic. The development of the Global Soil Spectral Library might be a step in the right direction

Electric field effect on the luminescence of KI:Tl

Thermoluminescence of KI:Tl, x- or &#946;-irradiated at T<77°K showed 2 main peaks at 105 and 170°K. They are resp. attributed to the recombination of mobile VK centers with Tl0 centers and to the recombination of thermally released electrons from Tl0 centers with Tl2+ centres. Similar experiments performed under static electric fields (E<40 kV cm-1) show that the intensity of the 2nd glow peak is strongly reduced. The relative intensity variation is anticorrelated with the intensity of glow peaks occurring at >230°K. We suggestthat in the temperature range in which Tl0 centres are thermally ionised, the effect of the electric field favour the retrapping of these electrons on other traps (still unknown). Irradiation doses also play an important role and their effects are studied at 77°K and T=200°K

Determinants of new drugs prescription in the Swiss healthcare market.

Drug markets are very complex and, while many new drugs are registered each year, little is known about what drives the prescription of these new drugs. This study attempts to lift the veil from this important subject by analyzing simultaneously the impact of several variables on the prescription of novelty. Data provided by four Swiss sickness funds were analyzed. These data included information about more than 470,000 insured, notably their drug intake. Outcome variable that captured novelty was the age of the drug prescribed. The overall variance in novelty was partitioned across five levels (substitutable drug market, patient, physician, region, and prescription) and the influence of several variables measured at each of these levels was assessed using a non-hierarchical multilevel model estimated by Bayesian Markov Chain Monte Carlo methods. More than 92% of the variation in novelty was explained at the substitutable drug market-level and at the prescription-level. Newer drugs were prescribed in markets that were costlier, less concentrated, included more insured, provided more drugs and included more active substances. Over-the-counter drugs were on average 12.5 years older while generic drugs were more than 15 years older than non-generics. Regional disparities in terms of age of prescribed drugs could reach 2.8 years. Regulation of the demand has low impact, with little variation explained at the patient-level and physician-level. In contrary, the market structure (e.g. end of patent with generic apparition, concurrence among producers) had a strong contribution to the variation of drugs ages

Desarrollo y aplicacion de PCR multiple para la deteccion simultanea de tres virus de ADN en camote (Ipomoea batatas L.)

El virus colusivo del camote (SPCV, genero Cavemovirus), el virus del aclaramiento de venas del camote (SPVC, genero Solendovirus) y el virus del enrollamiento de hojas del camote (SPLCV, genero Begomovirus) son virus con genoma de ADN, presentes en el camote en infecciones virales simples o multliples. La identificacion y deteccion de estos virus es complicada, ya que con frecuencia son asintomaticos y estan en concentraciones bajas en las plantas de camote. Se desarrollo una PCR multiple (mPCR) con el objetivo de lograr la deteccion simultanea de SPVC, SPVCV y SPLCV (y Begomovirus relacionados); para ellos se seleccionaron cebadores especificos para SPCV y SPVCV, y se utilizaron cebadores degenerados para Begomovirus (desarrollados por Li et al. 2004). Para la optimizacion de parametros se usaron plantas de camote con infecciones simples y mixtas. Se optimizo la concentracion de cebadores (0,1-0, 3uM), MgCl2 (2,5-8,0mM), dNTPs (0.2-0.8 mM), Taq-polimerasa (2-4U), parametros en el termociclador (temperatura de hibridacion de 48-62 oC y el numero de ciclos de 29-35), y la cantidad de acidos nucleidos (50-300 ng). Para validar le mPCR se uso plantas de camote de una coleccion de germplasma in vitro que estaban infectados con los virus en estudio y fueron confirmados por clonacion y secuenciamiento de las amplificaciones obtenidas. Los pares de cebadores especificos seleccionados para cada virus pudieron amplificar fragmentos de ADN en tamanos esperados, a una concentracion final de 0.16 uM para cebadores de SPCV y SPVCV, y 0.2uM para SPLCV. Ademas la concentracion de ADN adecuada esta entre 50-100 ng, con 30 ciclos termicos y 53 oC de temperatura de hibridacion. Este ensayo demostro ser simple, sensible y confiable para el diagnostico de rutina de SPCV, SPVCV y SPLCV (y Begomovirus relacionados). El ensayo de mPCR sera util para programas de cuarentena, como un metodos rapido y rentable para un gran numero de muestras

Are you really my clone? Identity verification of the in-trust sweetpotato collection at the International Potato Center.

The global in-trust sweetpotato collection maintained by the International Potato Center (CIP) in Lima, Peru consists of over 5,000 cultivated sweetpotato accessions maintained as clones in vitro as well as over 1,000 accessions from 67 species of Ipomoea maintained as seed populations. The clonal sweetpotato collection at CIP was initiated in the 1980’s and for 60% of the collection, original material still exists as potted plants in the greenhouse. This provides a unique opportunity where genetic integrity of a clonal collection, maintained in vitro for the past thirty years, can be confirmed by a side-by-side comparison of the same accession from the greenhouse. Initial molecular comparison is done using a set of twenty SSR primers followed by side-by-side comparison in the field using 30 morphological descriptors. Confirmation of identity requires both genetic and morphological analysis as a low percentage of the accessions appear to be duplicates based on SSR yet are morphologically distinct. Historical morphological descriptor data is used as a check to confirm identity and is being used as the sole check for accessions where we do not have original material for comparison. SSR results from 70% of the collection has confirmed that 85% of the in vitro accessions are true-to-type. In vitro accessions which are not true-to-type are reisolated and cleaned of viruses from the confirmed true-to-type greenhouse accessions. Accessions which are true-to-type are fingerprinted using DArTseq to provide a sequence-based fingerprint

PIRATE project: point-of-care, informatics-based randomised controlled trial for decreasing overuse of antibiotic therapy in Gram-negative bacteraemia.

Antibiotic overuse drives antibiotic resistance. The optimal duration of antibiotic therapy for Gram-negative bacteraemia (GNB), a common community and hospital-associated infection, remains unknown and unstudied via randomised controlled trials (RCTs). This investigator-initiated, multicentre, non-inferiority, informatics-based point-of-care RCT will randomly assign adult hospitalised patients receiving microbiologically efficacious antibiotic(s) for GNB to (1) 14 days of antibiotic therapy, (2) 7 days of therapy or (3) an individualised duration determined by clinical response and 75% reduction in peak C reactive protein (CRP) values. The randomisation will occur in equal proportions (1:1:1) on day 5 (±1) of efficacious antibiotic therapy as determined by antibiogram; patients, their physicians and study investigators will be blind to treatment duration allocation until the day of antibiotic discontinuation. Immunosuppressed patients and those with GNB due to complicated infections (endocarditis, osteomyelitis, etc) and/or non-fermenting bacilli ( &lt;i&gt;Acinetobacter&lt;/i&gt; spp, &lt;i&gt;Burkholderia&lt;/i&gt; spp, &lt;i&gt;Pseudomonas&lt;/i&gt; spp) &lt;i&gt;Brucella&lt;/i&gt; spp, &lt;i&gt;Fusobacterium&lt;/i&gt; spp or polymicrobial growth with Gram-positive organisms will be ineligible. The primary outcome is incidence of clinical failure at day 30; secondary outcomes include clinical failure, all-cause mortality and incidence of &lt;i&gt;Clostridiumdifficile&lt;/i&gt; infection in the 90-day study period. An interim safety analysis will be performed after the first 150 patients have been followed for ≤30 days. Given a chosen margin of 10%, the required sample size to determine non-inferiority is roughly 500 patients. Analyses will be performed on both intention-to-treat and per-protocol populations. Ethics approval was obtained from the cantonal ethics committees of all three participating sites. Results of the main trial and each of the secondary endpoints will be submitted for publication in a peer-reviewed journal. This trial is registered at www.clinicaltrials.gov (NCT03101072; pre-results)

Individual and Multi Vortex Pinning in Systems with Periodic Pinning Arrays

We examine multi and individual vortex pinning in thin superconductors with periodic pinning arrays. For multi-vortex pinning we observe peaks in the critical current of equal magnitude at every matching field, while for individual vortex pinning we observe a sharp drop in the critical current after the first matching field in agreement with experiments. We examine the scaling of the critical current at commensurate and incommensurate fields for varied pinning strength and show that the depinning force at incommensurate fields decreases faster than at the commensurate fields.Comment: 4 figuure