452 research outputs found
An Alternate Method for Fourier Transform Infrared (FTIR) Spectroscopic Determination of Soil Nitrate Using Derivative Analysis and Sample Treatments
This study aimed at examining effective sample treatments and spectral processing for an alternate method of soil nitrate determination using the attenuated total reflectance (ATR) of Fourier transform infrared (FTIR) spectroscopy. Prior to FTIR measurements, soil samples were prepared as paste to enhance adhesion between the ATR crystal and sample. The similar nitrate peak heights of soil pastes and their supernatants indicated that the nitrate in the liquid portion of the soil paste mainly responded to the FTIR signal. Using a 0.01-M CaSO4 solution for the soil paste, which has no interference bands in the characteristic spectra of the analyte, increased the concentration of the nitrates to be measured. Second-order derivatives were used in the prediction model to minimize the interference effects and enhance the performance. The second-order derivative spectra contained a unique nitrate peak in a range of 1,400-1,200 cm(-1) without interference of carbonate. A partial least square regression model using second-order derivative spectra performed well (R (2) = 0.995, root mean square error (RMSE) = 23.5, ratio of prediction to deviation (RPD) = 13.8) on laboratory samples. Prediction results were also good for a test set of agricultural field soils with a CaCO3 concentration of 6% to 8% (R (2) = 0.97, RMSE = 18.6, RPD = 3.5). Application of the prediction model based on soil paste samples to nitrate stock solution resulted in an increased RMSE (62.3); however, validation measures were still satisfactory (R (2) = 0.99, RPD = 3.0
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Double-Duty Actions: Seizing Program and Policy Opportunities to Address Malnutrition in all its Forms
Actions to address different forms of malnutrition are typically managed by separate communities, policies, programmes, governance structures, and funding streams. In contrast, double duty actions, which aim to simultaneously tackle both undernutrition and problems of overweight, obesity and diet-related non-communicable diseases (DR-NCDs) have been proposed as a way to effectively address malnutrition in all its forms in a more holsitic way. This paper identifies ten double duty actions that have strong potential to reduce the risk of both undernutrition and obesity/DR-NCDs. It does so by : 1) summarizing evidence on common drivers of different forms of malnutrition; 2) documenting examples of unintended harm caused by some undernutrition-focused programmes on obesity/DR-NCDs; and 3) highlighting a few examples of first double duty actions undertaken to tackle multiple forms of malnutrition. We find that undernutrition and obesity/DR-NCDs are intrinsically linked through early life nutrition; dietary quality; food environments; and socioeconomic factors. There is some evidence that undernutrition-focused programs have raised risks of poor quality diets and obesity/DR-NCDs, especially in countries undergoing a rapid nutrition transition. The paper builds on this evidence to develop a framework to guide the design of double duty approaches and strategies, and defines the first steps needed to deliver them. With a clear package of double duty actions now identified, there is an urgent need to move forward with double duty actions to address malnutrition in all its forms
Low-Frequency Noise Phenomena in Switched MOSFETs
In small-area MOSFETs widely used in analog and RF circuit design, low-frequency (LF) noise behavior is increasingly dominated by single-electron effects. In this paper, the authors review the limitations of current compact noise models which do not model such single-electron effects. The authors present measurement results that illustrate typical LF noise behavior in small-area MOSFETs, and a model based on Shockley-Read-Hall statistics to explain the behavior. Finally, the authors treat practical examples that illustrate the relevance of these effects to analog circuit design. To the analog circuit designer, awareness of these single-electron noise phenomena is crucial if optimal circuits are to be designed, especially since the effects can aid in low-noise circuit design if used properly, while they may be detrimental to performance if inadvertently applie
Cross-site collaboration on infection prevention and control researchâroom for improvement? A 7-year comparative study in five European countries
Background: The spread of SARS-CoV-2, multidrug-resistant organisms and other healthcare-associated pathogens represents supra-regional challenges for infection prevention and control (IPC) specialists in every European country. To tackle these problems, cross-site research collaboration of IPC specialists is very important. This study assesses the extent and quality of national research collaborations of IPC departments of university hospitals located in Austria, England, France, Germany, and the Netherlands, identifies network gaps, and provides potential solutions. Methods: Joint publications of IPC heads of all university hospitals of the included countries between 1st of June 2013 until 31st of May 2020 were collected by Pubmed/Medline search. Further, two factors, the journal impact factor and the type/position of authorship, were used to calculate the Scientific Collaboration Impact (SCI) for all included sites; nationwide network analysis was performed. Results: In five European countries, 95 sites and 125 responsible leaders for IPC who had been in charge during the study period were identified. Some countries such as Austria have only limited national research cooperations, while the Netherlands has established a gapless network. Most effective collaborating university site of each country were Lille with an SCI of 1146, Rotterdam (408), Berlin (268), Sussex (204), and Vienna/Innsbruck (18). Discussion: The present study indicates major differences and room for improvement in IPC research collaborations within each country and underlines the potential and importance of collaborating in IPC
Microsatellites for the Amazonian Fish Hypophthalmus marginatus
We isolated 41 and characterized 17 microsatellite loci for evaluating the genetic structure of the Amazonian fish Hypophthalmus marginatus, from the Tocantins and Araguaia River in the Eastern Amazonia. Of the 17 selected microsatellite sequences, 15 were dinucleotide repeats, 9 of which were perfect (5â31 repetitions) and 6 were composite motifs. Among these 17 microsatellites, only two were polymorphic. The average number of alleles (Na) observed in the five examined populations ranged from 3.5 to 4.5, while the average observed heterozygosity (Ho) ranged from 0.3 to 0.6. The allelic frequency was less homogeneous at the locus Hm 5 than that for the Hm 13. Genetic diversity was measured in three upstream and two downstream populations under the influence of the TucuruĂ Hydroelectric Dam. Our findings provide evidence for low levels of genetic diversity in H. marginatus of the Tocantis basin possibility related to the Dam construction. The Fst and Rst analysis fits well with migratory characteristics of H. marginatus, suggesting the existence of a gene flow mainly in the upstream or downstream directions. To test the hypothesis that the Dam was responsible for the detected reduction on this species genetic diversity, a large number of genetic markers are recommended, covering geographic distribution range of the fish species
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Parents' Experiences of Receiving the Initial Positive Newborn Screening (NBS) Result for Cystic Fibrosis and Sickle Cell Disease
The clinical advantages of the newborn screening programme (NBS) in the UK are well described in the literature. However, there has been little exploration of the psychosocial impact on the family. This study followed the principles of grounded theory to explore parents' experiences of receiving the initial positive NBS result for their child with cystic fibrosis (CF) or sickle cell disease (SCD). Semi-structured, qualitative interviews were conducted with 22 parents (12 mothers and 10 fathers) whose children had been diagnosed with CF or SCD via NBS and were under the age of 1Â year at the time of interview. The main themes that arose from the data were; parents previous knowledge of the condition and the NBS programme, the method of delivery and parental reactions to the result, sharing the results with others, the impact on parental relationships and support strategies. Study conclusions indicate that most parents thought initial positive NBS results should be delivered by a health professional with condition specific knowledge, preferably with both parents present. Genetic counselling needs to include a focus on the impact of NBS results on parental relationships. Careful consideration needs to be given to strategies to support parents of babies who have positive NBS results both in terms of the psychological health and to assist them in sharing the diagnosis
Glioblastoma adaptation traced through decline of an IDH1 clonal driver and macro-evolution of a double-minute chromosome
Background: Glioblastoma (GBM) is the most common malignant brain cancer occurring in adults, and is associated with dismal outcome and few therapeutic options. GBM has been shown to predominantly disrupt three core pathways through somatic aberrations, rendering it ideal for precision medicine approaches. Methods: We describe a 35-year-old female patient with recurrent GBM following surgical removal of the primary tumour, adjuvant treatment with temozolomide and a 3-year disease-free period. Rapid whole-genome sequencing (WGS) of three separate tumour regions at recurrence was carried out and interpreted relative to WGS of two regions of the primary tumour. Results: We found extensive mutational and copy-number heterogeneity within the primary tumour. We identified a TP53 mutation and two focal amplifications involving PDGFRA, KIT and CDK4, on chromosomes 4 and 12. A clonal IDH1 R132H mutation in the primary, a known GBM driver event, was detectable at only very low frequency in the recurrent tumour. After sub-clonal diversification, evidence was found for a whole-genome doubling event and a translocation between the amplified regions of PDGFRA, KIT and CDK4, encoded within a double-minute chromosome also incorporating miR26a-2. The WGS analysis uncovered progressive evolution of the double-minute chromosome converging on the KIT/PDGFRA/PI3K/mTOR axis, superseding the IDH1 mutation in dominance in a mutually exclusive manner at recurrence, consequently the patient was treated with imatinib. Despite rapid sequencing and cancer genome-guided therapy against amplified oncogenes, the disease progressed, and the patient died shortly after. Conclusion: This case sheds light on the dynamic evolution of a GBM tumour, defining the origins of the lethal sub-clone, the macro-evolutionary genomic events dominating the disease at recurrence and the loss of a clonal driver. Even in the era of rapid WGS analysis, cases such as this illustrate the significant hurdles for precision medicine success
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