1,168 research outputs found
Consolidated Markets, Brand Competition, and Orange Juice Prices
This paper examines how consolidation in the marketing system affects prices for orange juice. We isolated the pricing behavior of brand marketers, wholesalers, and retailers by observing the retail prices for specific orange juice products, including leading national brands and private label brands, in 54 U.S. markets over a 1-year period. The data provided little compelling evidence that consolidated markets engaged in non-competitive pricing behavior. Increased brand competition, particularly between private labels and leading national brands, did, however, appear to lower average market prices.consumer demographics, national brands, orange juice, price behavior, private labels, wholesaler concentration, retailer concentration, Demand and Price Analysis, Industrial Organization,
Nasopharyngeal Swabs vs. Nasal Aspirates for Respiratory Virus Detection: A Systematic Review
Nasal pathogen detection sensitivities can be as low as 70% despite advances in molecular diagnostics. This may be linked to the choice of sampling method. A diagnostic test accuracy review for sensitivity was undertaken to compare sensitivity of swabbing to the nasopharynx and extracting nasal aspirates, using the PRISMA protocol, Cochrane rapid review methodology, and QUADAS-2 risk of bias tools, with meta-analysis of included studies. Sensitivities were calculated by a consensus standard of positivity by either method as the ‘gold standard.’ Insufficient sampling methodology, cross sectional study designs, and studies pooling samples across anatomical sites were excluded. Of 13 subsequently eligible studies, 8 had ‘high’ risk of bias, and 5 had ‘high’ applicability concerns. There were no statistical differences in overall sensitivities between collection methods for eight different viruses, and this did not differ with use of PCR, immunofluorescence, or culture. In one study alone, Influenza H1N1(2009) favored nasopharyngeal swabs, with aspirates having 93.3% of the sensitivity of swabs (p > 0.001). Similarly equivocal sensitivities were noted in reports detecting bacteria. The chain of sampling, from anatomical site to laboratory results, features different potential foci along which sensitivity may be lost. A fair body of evidence exists that use of a different sampling method will not yield more respiratory pathogens
Estimation of Effective Lens Position Using a Method Independent of Preoperative Keratometry Readings
Purpose
To evaluate the validity of a keratometry (K)-independent method of estimating effective lens position (ELP) before phacoemulsification cataract surgery. Setting
Institute of Eye Surgery, Whitfield Clinic, Waterford, Ireland. Design
Evaluation of diagnostic test or technology. Methods
The anterior chamber diameter and corneal height in eyes scheduled for cataract surgery were measured with a rotating Scheimpflug camera. Corneal height and anterior chamber diameter were used to estimate the ELP in a K-independent method (using the SRK/T [ELPrs] and Holladay 1 [ELPrh] formulas). Results
The mean ELP was calculated using the traditional (mean ELPs 5.59 mm ± 0.52 mm [SD]; mean ELPh 5.63 ± 0.42 mm) and K-independent (mean ELPrs 5.55 ± 0.42 mm; mean ELPrh ± SD 5.60 ± 0.36 mm) methods. Agreement between ELPs and ELPrs and between ELPh and ELPrh were represented by Bland-Altman plots, with mean differences (± 1.96 SD) of 0.06 ± 0.65 mm (range −0.59 to +0.71 mm; P=.08) in association with ELPrs and −0.04 ± 0.39 mm (range −0.43 to +0.35 mm; P=.08) in association with ELPrh. The mean absolute error for ELPs versus ELPrs estimation and for ELPh versus ELPrh estimation was 0.242 ± 0.222 mm (range 0.001 to 1.272 mm) and 0.152 ± 0.137 mm (range 0.001 to 0.814 mm), respectively. Conclusion
This study confirms that the K-independent ELP estimation method is comparable to traditional K-dependent methods and may be useful in post-refractive surgery patients
The Fate of Foodborne Pathogens in Manure Treated Soil
Publication history: Accepted - 22 November 2021; Published online - 10 December 2021.The aim of this review was to provide an update on the complex relationship between
manure application, altered pathogen levels and antibiotic resistance. This is necessary
to protect health and improve the sustainability of this major farming practice in
agricultural systems based on high levels of manure production. It is important to
consider soil health in relation to environment and land management practices in
the context of the soil microflora and the introduction of pathogens on the health of
the soil microbiome. Viable pathogens in manure spread on agricultural land may be
distributed by leaching, surface run-off, water source contamination and contaminated
crop removal. Thus it is important to understand how multiple pathogens can persist in
manures and on soil at farm-scale and how crops produced under these conditions
could be a potential transfer route for zoonotic pathogens. The management of
pathogen load within livestock manure is a potential mechanism for the reduction
and prevention of outbreaks infection with Escherichia coli, Listeria Salmonella, and
Campylobacter. The ability of Campylobacter, E. coli, Listeria and Salmonella to combat
environmental stress coupled with their survival on food crops and vegetables postharvest emphasizes the need for further study of these pathogens along with the
emerging pathogen Providencia given its link to disease in the immunocompromised
and its’ high levels of antibiotic resistance. The management of pathogen load within
livestock manure has been widely recognized as a potential mechanism for the reduction
and prevention of outbreaks infection but any studies undertaken should be considered
as region specific due to the variable nature of the factors influencing pathogen content
and survival in manures and soil. Mediocre soils that require nutrients could be one
template for research on manure inputs and their influence on soil health and on
pathogen survival on grassland and in food crops.This work was funded by the Department of Agriculture, Environment and Rural Affairs (DAERA); https://www.daera-ni.gov.uk) as part of the DAERA Postgraduate Studentship Programme and by the DAERA Evidence and Innovation project 18/1/21: Evaluating the impact of a range of organic manures applied to arable land on soil, crop and NI agriculture
Autosomal dominant reticuloendothelial iron overload associated with a 3-base pair deletion in the ferroportin 1 gene (SLC11A3)
We describe a family with autosomal dominant inheritance of increased body iron stores characterized by raised serum ferritin concentration and normal transferrin saturation. Liver biopsy showed iron deposition in Kupffer cells without fibrosis. The clinical features of HFE-related hemochromatosis were absent, as were the Cys282Tyr and His63Asp mutations. Venesection therapy was poorly tolerated, suggesting a defect in iron release from reticuloendothelial stores. A 3-base pair deletion in exon 5 of the ferroportin 1 gene (SLC11A3) predicting Val162 deletion was found in affected members, but not in unaffected individuals or in 100 control subjects. Consensus structural predictions of the transmembrane helices showed that the deletion is in the extracellular loop between the third and fourth predicted transmembrane helices and lies within a spatial cluster of other known ferroportin 1 mutations. These results indicate that this extracellular cluster is functionally important for iron transport, and its disruption leads to iron overload
Mammut pacificus sp. nov., a newly recognized species of mastodon from the Pleistocene of western North America
A new species of mastodon from the Pleistocene of western North America, Mammut pacificus sp. nov. is herein recognized, with specimens identified throughout California and from two localities in southern Idaho. This new taxon differs from the contemporaneous M. americanum in having narrower teeth, most prominently in M3/m3, as well as six sacral vertebrae, femur with a proportionally greater mid-shaft diameter, and no mandibular tusks at any growth stage. All known Pleistocene Mammut remains from California are consistent with our diagnosis of M. pacificus, which indicates that M. americanum was not present in California
Biological and synthetic surfactant exposure increases antimicrobial gene occurrence in a freshwater mixed microbial biofilm environment
Publication history: Accepted - 8 March 2023; Published - 17 March 2023.Aquatic habitats are particularly susceptible to chemical pollution, such as antimicrobials, from domestic, agricultural, and industrial sources. This has led to the rapid increase of antimicrobial resistance (AMR) gene prevalence. Alternate approaches to counteract pathogenic bacteria are in development including synthetic and biological surfactants such as sodium dodecyl sulfate (SDS) and rhamnolipids. In the aquatic environment, these surfactants may be present as pollutants with the potential to affect biofilm formation and AMR gene occurrence. We tested the effects of rhamnolipid and SDS on aquatic biofilms in a freshwater stream in Northern Ireland. We grew biofilms on contaminant exposure substrates deployed within the stream over 4 weeks. We then extracted DNA and carried out shotgun sequencing using a MinION portable sequencer to determine microbial community composition, with 16S rRNA analyses (64,678 classifiable reads identified), and AMR gene occurrence (81 instances of AMR genes over 9 AMR gene classes) through a metagenomic analysis. There were no significant changes in community composition within all systems; however, biofilm exposed to rhamnolipid had a greater number of unique taxa as compared to SDS treatments and controls. AMR gene prevalence was higher in surfactant-treated biofilms, although not significant, with biofilm exposed to rhamnolipids having the highest presence of AMR genes and classes compared to the control or SDS treatments. Our results suggest that the presence of rhamnolipid encourages an increase in the prevalence of AMR genes in biofilms produced in mixed-use water bodies.EPSRC, Grant/Award Number: EP/P032427/1; University of Ulste
Proteomics Analysis and Protein Expression during Sporozoite Excystation of Cryptosporidium parvum (Coccidia, Apicomplexa)
Cryptosporidiosis, caused by coccidian parasites of the genus Cryptosporidium, is a major cause of human gastrointestinal infections and poses a significant health risk especially to immunocompromised patients. Despite intensive efforts for more than 20 years, there is currently no effective drug treatment against these protozoa. This study examined the zoonotic species Cryptosporidium parvum at two important stages of its life cycle: the non-excysted (transmissive) and excysted (infective) forms. To increase our understanding of the molecular basis of sporozoite excystation, LC-MS/MS coupling with a stable isotope N-terminal labeling strategy using iTRAQ (TM) reagents was used on soluble fractions of both non-excysted and excysted sporozoites, i.e. sporozoites both inside and outside oocysts were examined. Sporozoites are the infective stage that penetrates small intestinal enterocytes. Also to increase our knowledge of the C. parvum proteome, shotgun sequencing was performed on insoluble fractions from both non-excysted and excysted sporozoites. In total 303 C. parvum proteins were identified, 56 of which, hitherto described as being only hypothetical proteins, are expressed in both excysted and non-excysted sporozoites. Importantly we demonstrated that the expression of 26 proteins increases significantly during excystation. These excystation-induced proteins included ribosomal proteins, metabolic enzymes, and heat shock proteins. Interestingly three Apicomplexa-specific proteins and five Cryptosporidium-specific proteins augmented in excysted invasive sporozoites. These eight proteins represent promising targets for developing vaccines or chemotherapies that could block parasite entry into host cells
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Impaired HA-specific T follicular helper cell and antibody responses to influenza vaccination are linked to inflammation in humans.
Funder: National Institute for Health Research (NIHR)Antibody production following vaccination can provide protective immunity to subsequent infection by pathogens such as influenza viruses. However, circumstances where antibody formation is impaired after vaccination, such as in older people, require us to better understand the cellular and molecular mechanisms that underpin successful vaccination in order to improve vaccine design for at-risk groups. Here, by studying the breadth of anti-haemagglutinin (HA) IgG, serum cytokines, and B and T cell responses by flow cytometry before and after influenza vaccination, we show that formation of circulating T follicular helper (cTfh) cells was associated with high-titre antibody responses. Using Major Histocompatability Complex (MHC) class II tetramers, we demonstrate that HA-specific cTfh cells can derive from pre-existing memory CD4+ T cells and have a diverse T cell receptor (TCR) repertoire. In older people, the differentiation of HA-specific cells into cTfh cells was impaired. This age-dependent defect in cTfh cell formation was not due to a contraction of the TCR repertoire, but rather was linked with an increased inflammatory gene signature in cTfh cells. Together, this suggests that strategies that temporarily dampen inflammation at the time of vaccination may be a viable strategy to boost optimal antibody generation upon immunisation of older people
Monocyte-macrophage ferric reductase activity is inhibited by iron and stimulated by cellular differentiation
The enzyme ferric reductase catalyses the reduction of Fe(III) as a prerequisite to its transportation across the cell membrane. Duodenal mucosal biopsies from iron overloaded patients with genetic haemochromatosis (GH) have increased ferric reductase activity and iron absorption compared with controls, yet the GH mucosa is iron deficient. A similar GH-related iron deficiency is also seen in macrophages. The aim of this study was to investigate whether macrophage ferric reductase activity is altered in GH, and to determine ferric reductase activity in monocytes and differentiated macrophages. The erythroleukaemic K562 cell line was studied as a clonal reference cell line. The basal K562 ferric reductase activity is characteristic of a membrane bound enzyme, being both temperature and protease sensitive. Ferric reductase activity was also demonstrated in human leucocyte, monocyte and macrophage preparations. Assays of K562 and macrophage cell supernatants confirmed that the ferric reductase activity was not due to a secreted factor. Assay of ferric reductase in normalized-iron and iron-enriched (100 microM ferric citrate) conditions showed no significant difference between Cys282Tyr (Cys282-->Tyr) homozygous GH macrophages and Cys282-Tyr negative control activities (P>0.05). However, a 900% increase in ferric reductase activity was observed during monocyte to macrophage differentiation (P<0.05), possibly reflecting the co-ordinate up-regulation of iron metabolism in these cells. The demonstration of approx. 25% activity after macrophage differentiation at high free-iron concentrations compared with 'normalized' iron is consistent with repression of human ferric reductase activity by iron. The identification of the human ferric reductase gene and its protein will ultimately provide insight into its regulation and role in mammalian iron metabolism
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