400 research outputs found
Greenhouse Evaluation of Air-Assisted Delivery Parameters for Mature Poinsettias
Understanding the performance characteristics of application equipment is important for helping make the most efficacious applications. While handguns making high volume applications are common in greenhouse production, it is difficult to achieve uniform distribution of product in a timely manner. Broadcast applications made using air-assistance can help aid canopy penetration and the volume of carrier required to make applications. The objectives of this research were to determine how air-assist sprayer application parameters influence spray deposits on the undersides of leaves in a mature poinsettia canopy. Bench-top trials were conducted using a motorized boom inside a greenhouse to treat a mature and dense poinsettia canopy. Sprayer treatments applied a tank mix of water and fluorescent tracer. Nylon screen targets were secured to the underside surfaces of leaves in the upper and lower elevation of target plants. A five-port, air-assist nozzle with flat fan nozzle tips was used to make the applications. Three air outlet speeds, two travel speeds, and three nozzle flow rates were evaluated. Each treatment was replicated three times. Spray deposits were highly variable. Upper elevation spray deposits were significantly greater than lower elevation deposits. Individually, higher air outlet speed (36.0 m s(-1)), slower travel speed (3.2 km h(-1)), and higher nozzle flow rate (1.17 L min(-1)) tended to produce higher sprayer deposits on the underside surfaces of leaves. The combination of travel speed and nozzle flow rate that produced the highest application rate (900 L ha(-1)) also produced the highest deposits. There was a 500% increase in underside leaf surface deposits in the lower canopy area for a corresponding 500% increase in application rate. However, the main effects produced no significant differences in spray deposits in the lower canopy area. Further improvements in directing sprays or providing canopy turbulence are necessary to improve deposition and management of insect pests feeding on the underside of poinsettia leaves
FTIR-ATR, FT-RAMAN and GC-FID assessment of discrimination of aged wine spirits under different conditions
info:eu-repo/semantics/publishedVersio
Genetic and Antigenic Analysis of the First A/New Caledonia/20/99-like H1N1 Influenza Isolates Reported in the Americas
From February through May of 1999, 13 cases of Influenza A virus (FLUAV), type H1N1 were reported at a Department of Defense influenza surveillance sentinel site in Lima, Peru. Genetic and antigenic analysis by hemagglutination inhibition and direct nucleotide sequencing of the HA1 region of the hemagglutinin gene were performed on two isolates, A/Peru/1641/99 and A/Peru/1798/99. Both isolates were distinct from the Bayern/7/95-like viruses circulating in the Americas and closely related to a Beijing/262/95-like variant, A/New Caledonia/20/99. With the exception of travel-related cases, the detection of these isolates represents the first appearance of New Caledonia/20/99-like viruses in the Americas. Since the characterization of these Peru isolates, a number of New Caledonia/20/99-like viruses have been reported worldwide. For the 2000/01 and 2001/02 influenza seasons, the World Health Organization (WHO) has recommended the inclusion of A/New Caledonia/20/99 as the H1N1 vaccine component for both the southern and northern hemispheres
Safety of etanercept in the treatment of rheumatic disease patients with Hepatitis C virus infection
info:eu-repo/semantics/publishedVersio
Volatile phenols in aged wine spirits: role, contents and impact of ageing systems
The volatile phenols (eugenol, guaiacol, 4-methylguaiacol, syringol, 4-methylsyringol and 4-allylsyringol) are odorant compounds
that may exist in aged wine spirits resulting from their contact with wooden barrels during the ageing process. These compounds,
which are originated from wood lignin’s, revealed an important sensory impact in aged wine spirits due to their low sensory
thresholds and correlations with sensory attributes such as woody, toasted, smoke, which have a close relationship with the
quality of these beverages. The wine spirits are traditionally aged in wooden barrels but the use of wood fragments, with or
without micro-oxygenation, is a technological alternative that has been recently studied by our team with promising results. This
work presents an overview of volatile phenols’ amounts in wine spirits aged in wooden barrels during different ageing times and
using two kinds of wood (chestnut versus oak). These compounds were quantified by GC-FID, after a previous extraction and
concentration steps, and their identification was assessed by GC-MS. It is also examined the results and the impact of alternative
technologies on the amounts of such compounds. The ANOVA results showed a significant effect of the ageing system and the
wood botanical species on the volatile phenols contentsinfo:eu-repo/semantics/publishedVersio
A functional genomic approach to identify reference genes for human pancreatic beta cell real-time quantitative RT-PCR analysis
Exposure of human pancreatic beta cells to pro-inflammatory cytokines or metabolic stressors is used to model events related to type 1 and type 2 diabetes, respectively. Quantitative real-time PCR is commonly used to quantify changes in gene expression. The selection of the most adequate reference gene(s) for gene expression normalization is an important pre-requisite to obtain accurate and reliable results. There are no universally applicable reference genes, and the human beta cell expression of commonly used reference genes can be altered by different stressors. Here we aimed to identify the most stably expressed genes in human beta cells to normalize quantitative real-time PCR gene expression. We used comprehensive RNA-sequencing data from the human pancreatic beta cell line EndoC-βH1, human islets exposed to cytokines or the free fatty acid palmitate in order to identify the most stably expressed genes. Genes were filtered based on their level of significance (adjusted P-value >0.05), fold-change (|fold-change| <1.5) and a coefficient of variation <10%. Candidate reference genes were validated by quantitative real-time PCR in independent samples. We identified a total of 264 genes stably expressed in EndoC-βH1 cells and human islets following cytokines–or palmitate-induced stress, displaying a low coefficient of variation. Validation by quantitative real-time PCR of the top five genes ARF1, CWC15, RAB7A, SIAH1 and VAPA corroborated their expression stability under most of the tested conditions. Further validation in independent samples indicated that the geometric mean of ACTB and VAPA expression can be used as a reliable normalizing factor in human beta cells
Disentangling post-vaccination symptoms from early COVID-19
Background: Identifying and testing individuals likely to have SARS-CoV-2 is critical for infection control, including post-vaccination. Vaccination is a major public health strategy to reduce SARS-CoV-2 infection globally. Some individuals experience systemic symptoms post-vaccination, which overlap with COVID-19 symptoms. This study compared early post-vaccination symptoms in individuals who subsequently tested positive or negative for SARS-CoV-2, using data from the COVID Symptom Study (CSS) app. Methods: We conducted a prospective observational study in 1,072,313 UK CSS participants who were asymptomatic when vaccinated with Pfizer-BioNTech mRNA vaccine (BNT162b2) or Oxford-AstraZeneca adenovirus-vectored vaccine (ChAdOx1 nCoV-19) between 8 December 2020 and 17 May 2021, who subsequently reported symptoms within seven days (N=362,770) (other than local symptoms at injection site) and were tested for SARS-CoV-2 (N=14,842), aiming to differentiate vaccination side-effects per se from superimposed SARS-CoV-2 infection. The post-vaccination symptoms and SARS-CoV-2 test results were contemporaneously logged by participants. Demographic and clinical information (including comorbidities) were recorded. Symptom profiles in individuals testing positive were compared with a 1:1 matched population testing negative, including using machine learning and multiple models considering UK testing criteria. Findings: Differentiating post-vaccination side-effects alone from early COVID-19 was challenging, with a sensitivity in identification of individuals testing positive of 0.6 at best. Most of these individuals did not have fever, persistent cough, or anosmia/dysosmia, requisite symptoms for accessing UK testing; and many only had systemic symptoms commonly seen post-vaccination in individuals negative for SARS-CoV-2 (headache, myalgia, and fatigue). Interpretation: Post-vaccination symptoms per se cannot be differentiated from COVID-19 with clinical robustness, either using symptom profiles or machine-derived models. Individuals presenting with systemic symptoms post-vaccination should be tested for SARS-CoV-2 or quarantining, to prevent community spread. Funding: UK Government Department of Health and Social Care, Wellcome Trust, UK Engineering and Physical Sciences Research Council, UK National Institute for Health Research, UK Medical Research Council and British Heart Foundation, Chronic Disease Research Foundation, Zoe Limited
Influence of steps on the tilting and adsorption dynamics of ordered Pn films on vicinal Ag(111) surfaces
Here we present a structural study of pentacene (Pn) thin films on vicinal
Ag(111) surfaces by He atom diffraction measurements and density functional
theory (DFT) calculations supplemented with van der Waals (vdW) interactions.
Our He atom diffraction results suggest initial adsorption at the step edges
evidenced by initial slow specular reflection intensity decay rate as a
function of Pn deposition time. In parallel with the experimental findings, our
DFT+vdW calculations predict the step edges as the most stable adsorption site
on the surface. An isolated molecule adsorbs as tilted on the step edge with a
binding energy of 1.4 eV. In addition, a complete monolayer (ML) with
pentacenes flat on the terraces and tilted only at the step edges is found to
be more stable than one with all lying flat or tilted molecules, which in turn
influences multilayers. Hence our results suggest that step edges can trap Pn
molecules and act as nucleation sites for the growth of ordered thin films with
a crystal structure similar to that of bulk Pn.Comment: 4 pages, 4 figures, 1 tabl
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