A simple methodology to estimate plant volume in nitrous oxide emission studies

Closed-chamber methodology is widely used for the estimation of greenhouse gas (GHG) emissions in agricultural systems. The volume displaced by plants inside chambers influences GHG flux estimation, although generally it is not discounted from chamber headspace in the calculation. A novel image analysis–based procedure is proposed to estimate plant volume and to assess its impact on nitrous oxide (N2O) flux estimations in a wheat (Triticum aestivum L. ‘Rimbaud’) crop. A maximum of 2.2% of the 13-L chambers was displaced by plants, leading to a systematic 0.9% overestimation in cumulative N2O emissions if plant volume was not considered. Thus, plant canopy volume should be taken into account for improving the accuracy of emissions

Utility of stabilized nitrogen fertilizers to reduce nitrate leaching under optimal management practices

Background: The inadequate application of nitrogen (N) to crops has increased the reactive N in the atmosphere and in the surface and ground waters. Stabilized N-fertilizers with nitrification (NI) and urease (UI) inhibitors have been proposed to reduce these environmental problems without affecting or even increasing crop productivity. Aim: The objective of this study was to evaluate, in a maize–maize–wheat rotation, if the use of the NI 3, 4-dimethylpyrazole phosphate (DMPP) and the UIs N-(n-butyl) thiophosphoric triamide (NBPT) and monocarbamide dihydrogen sulfate (MCDHS) reduces N leaching without compromising yield under optimal management of N and water. Methods: The experiment was conducted in 24 drainage lysimeters with two soil types with contrasting water holding capacity under Mediterranean irrigated conditions. The fertilizer treatments were urea, urea with DMPP, urea with NBPT, and urea with MCDHS. For the maize crop, conventional fertilizer application was split into 6- and 13-leaf stages, whereas stabilized fertilizers were applied as a single application at the 6-leaf stage. All fertilizer treatments were applied at late tillering in the wheat crop. Results: The soil mineral N was measured at the beginning and the end of each crop season, but no differences were found among fertilizer treatments. Differences in the volume of water drained or the cumulative mass of nitrate depending on the fertilizer were not significant (three-year treatment average of 200 L m-2 and 22 kg N ha-1 in the Deep soil, and 334 L m-2 and 40 kg N ha-1 in the Shallow type, respectively). No consistent significant differences were found in agronomic parameters (chlorophyll measurements, yield, and total N uptake) between the fertilizer treatments. Conclusion: Based on the results, the use of stabilized N-fertilizer could be recommended to reduce the number of N applications in maize without compromising grain yield but with no advantages to reduce nitrate-leaching losses if N rates are managed properly under efficient irrigation management practices

Agronomic and environmental implications of substituting pig slurry for synthetic nitrogen in mediterranean wheat systems

Using slurries as fertilizers is a promising strategy for the reuse of nutrients and striving towards a circular economy. This study aims to assess the agronomic productivity and the environmental effects on Mediterranean sprinkler-irrigated wheat during three consecutive years of (1) the use of pig slurry (PS) as a substitute for a synthetic fertilizer (urea, U) and (2) the addition of a urease inhibitor (monocarbamide dihydrogen sulfate, MCDHS) to pig slurry (PSI). A nitrogen (N) target rate of 120 kg NH4+-N ha-1 as U, PS, or PSI (main factor) was applied at tillering, and it was supplemented with N application at stem elongation (secondary factor). Grain yield, nitrogen use efficiency indexes, and nitrous oxide emissions were not significantly affected by the N source, U, or PS; in contrast to grain protein that was affected by the N source (lower protein content in PS). The higher unaccounted N from soil balance in PS compared to U fertilization could be associated with higher ammonia volatilization, although additional studies should confirm this hypothesis. Our study suggests that, under the considered cropping conditions, PS does not affect productivity or N2O losses compared to U. The addition of MCDHS to pig slurry did not display agronomic or environmental benefits under the evaluated agro-environmental conditions

One size fits ball: Macrocyclic hosts for fullerenes with micromolar affinity

Date du colloque : 25/03/2012International audienc

Development and validation of a MEDLINE search filter/hedge for degenerative cervical myelopathy

Abstract Background Degenerative cervical myelopathy (DCM) is a common condition with many unmet clinical needs. Pooled analysis of studies is an important tool for advancing medical understanding. This process starts with a systematic search of the literature. Identification of studies in DCM is challenged by a number of factors, including non-specific terminology and index terms. Search filters or HEDGEs, are search strings developed and validated to optimise medical literature searches. We aimed to develop a search filter for DCM for the MEDLINE database. Methods The diagnostic test assessment framework of a “development dataset” and seperate “validation dataset” was used. The development dataset was formed by hand searching four leading spinal journals (Spine, Journal of Neurosurgery Spine, Spinal Cord and Journal of Spinal Disorders and Techniques) in 2005 and 2010. The search filter was initially developed focusing on sensitivity and subsequently refined using NOT functions to improve specificity. One validation dataset was formed from DCM narrative and systematic review articles and the second, articles published in April of 1989, 1993, 1997, 2001, 2005, 2009, 2013 and 2017 retrieved via the search MeSH term ‘Spine’. Metrics of sensitivity, specificity, precision and accuracy were used to test performance. Results Hand searching identified 77/1094 relevant articles for 2005 and 55/1199 for 2010. We developed a search hedge with 100% sensitivity and a precision of 30 and 29% for the 2005 and 2010 development datasets respectively. For the selected time periods, EXP Spine returned 2113 publications and 30 were considered relevant. The search filter identified all 30 relevant articles, with a specificity of 94% and precision of 20%. Of the 255 references listed in the narrative index reviews, 225 were indexed in MEDLINE and 165 (73%) were relevant articles. All relevant articles were identified and accuracy ranged from 67 to 97% over the three reviews. Of the 42 articles returned from 3 recent systematic reviews, all were identified by the filter. Conclusions We have developed a highly sensitive hedge for the research of DCM. Whilst precision is similarly low as other hedges, this search filter can be used as an adjunct for DCM search strategies

Esofagectomía transhiatal por vía abierta y vía laparoscópica para el cáncer de esófago: análisis de los márgenes de resección y ganglios linfáticos

Surgical treatment of cancer of the oesophagus is associated with a high morbidity and mortality. Minimally invasive surgery has been proposed as an alternative to try to reduce these complications; however, at this time there are not many studies that evaluate the oncological validity of this method. The objective of this work is to give a preliminary audit of the results of our experience in both surgical techniques, with special emphasis on the oncopathological aspects (resection margins and lymph nodes). MATERIAL AND METHOD: Between April 2003 and February 2007, 40 patients diagnosed with distal oesophageal cancer were surgically intervened at Charing Cross Hospital, London, 24 open and 16 by laparoscopy in accordance with the surgeon responsible. Of these, 50% received neoadjuvant chemotherapy. Both groups were homogeneous for age, sex, ASA, tumour stage and tumour location. In all cases, the pathological tumour stage (TNM), the tumour distal margin, tumour proximal margin, tumour circumference and number of resected lymph nodes, were collected in a data base. RESULTS: The number of resected lymph nodes was similar in both groups; (19 for open and 18 for laparoscopy). The mean distal tumour margin for the group treated by open surgery was 4.9 cm compared to 4.3 in the group treated by laparoscopy (p = 0.578). The mean proximal tumour margin for the group treated by open surgery was 8.4 cm compared to 4.6 cm in the laparoscopy group (p = 0.004) and tumour circumference margin was positive in 11 patients (45%) belonging to the open group compared to 5 patients (33%) in the laparoscopy group (p = 0.519). CONCLUSIONS: In our experience, laparoscopic surgery for cancer of the oesophagus appears to show similar initial results to those of open surgery as regards the number of resected lymph nodes and resection margins

Human prostate sphere-forming cells represent a subset of basal epithelial cells capable of glandular regeneration in vivo.

BackgroundProstate stem/progenitor cells function in glandular development and maintenance. They may be targets for tumor initiation, so characterization of these cells may have therapeutic implications. Cells from dissociated tissues that form spheres in vitro often represent stem/progenitor cells. A subset of human prostate cells that form prostaspheres were evaluated for self-renewal and tissue regeneration capability in the present study.MethodsProstaspheres were generated from 59 prostatectomy specimens. Lineage marker expression and TMPRSS-ERG status was determined via immunohistochemistry and fluorescence in situ hybridization (FISH). Subpopulations of prostate epithelial cells were isolated by cell sorting and interrogated for sphere-forming activity. Tissue regeneration potential was assessed by combining sphere-forming cells with rat urogenital sinus mesenchyme (rUGSM) subcutaneously in immunocompromised mice.ResultsProstate tissue specimens were heterogeneous, containing both benign and malignant (Gleason 3-5) glands. TMPRSS-ERG fusion was found in approximately 70% of cancers examined. Prostaspheres developed from single cells at a variable rate (0.5-4%) and could be serially passaged. A basal phenotype (CD44+CD49f+CK5+p63+CK8-AR-PSA-) was observed among sphere-forming cells. Subpopulations of prostate cells expressing tumor-associated calcium signal transducer 2 (Trop2), CD44, and CD49f preferentially formed spheres. In vivo implantation of sphere-forming cells and rUGSM regenerated tubular structures containing discreet basal and luminal layers. The TMPRSS-ERG fusion was absent in prostaspheres derived from fusion-positive tumor tissue, suggesting a survival/growth advantage of benign prostate epithelial cells.ConclusionHuman prostate sphere-forming cells self-renew, have tissue regeneration capability, and represent a subpopulation of basal cells

Cost analysis of the management of brain metastases in patients with advanced ALK+ NSCLC: alectinib versus crizotinib

Aim: To estimate management cost of NSCLC ALK+ patients with and without brain metastasis (BM), and to compare annual costs in patients treated with alectinib or crizotinib. Methods: Management cost/year (euro 2018) in patients with and without BM was estimated with disaggregated resource consumption provided by local oncologists, including medical visits, hospitalizations, diagnostic/laboratory tests, imaging techniques and surgical procedures. The comparison of costs/year with alectinib and crizotinib, considered the cumulative 12-month incidence of BM in ALEX trial (9.4 and 41.4%, respectively). Results: Management cost was euro6173.42/patient-year without BM and euro21,637.50/patient-year with BM. With alectinib, average cost/patient was lower than crizotinib (euro4948.51/patient-year). Conclusion: Prevention of BM with alectinib may result in reductions of cost/year in the management of advanced ALK+ NSCLC