62880 research outputs found
Sort by
DNA barcoding of tick species (Archnida: Ixodida) to support species identification and discovery of cryptic genetic diversity with emphasis on the British fauna
Full text linkTicks are of medical and veterinary concern due to their role as vectors of a wide range of pathogens, including viruses, protozoa, and bacteria. Accurate species identification is essential during tick surveillance and disease control programmes, as certain pathogens are associated with particular tick species. In this study, genetic variation of a partial sequence of the cytochrome c oxidase I (COI) gene was used for molecular identification of tick species to corroborate morphological identification. This also enabled investigation of cryptic diversity within tick species. Thirty species belonging to the genera Amblyomma, Argas, Carios, Dermacentor, Haemaphysalis, Hyalomma, Ixodes, Ornithodoros, and Rhipicephalus were assessed. Tree-topology analysis confirmed discrete clustering of specimens according to species for the majority of taxa. Intraspecific genetic divergence ranged from 0 to 6.08%. In taxa where species complexes are known, separation of discrete groups were found. Several species yielded >2% intraspecific genetic divergence when compared to other taxa, suggesting potential cryptic diversity. DNA barcoding was an effective approach for the morphological identification of UK and non-native ticks, and for the detection of cryptic diversity within species
The law of naval warfare and the U.S. capture of neutral merchant vessels: the case of the Marinera
No full textDairy intake and risk of type 2 diabetes and metabolic syndrome: a narrative review
Full text linkDairy products are important components of human health. While some studies claim that dairy increases the risk of type 2 diabetes (T2D) and metabolic syndrome (MetS), several large studies have shown the beneficial impact of dairy consumption. The objective of this review is to highlight the effect of dairy intake on T2D and MetS using recent evidence (published within the last decade) from large epidemiological studies, meta-analyses, randomized controlled trials (RCTs), and Mendelian randomization (MR) and multi-omics studies, and to provide plausible underlying biological mechanisms linking dairy consumption with the risk of T2D and MetS. Given the increasing prevalence of T2D and MetS, it is important to understand the benefits and/or risks of milk and dairy products in the diet. Based on all available evidence from large-scale epidemiological studies, MR analyses, and RCTs, the beneficial impact of dairy products as part of a healthy diet plan appears to be an additional way of mitigating the risk of T2D and MetS. The evidence for a protective effect appears to be undisputed for fermented dairy products like yogurt. For milk, most studies were either protective or neutral, with very few showing a deleterious effect, and with respect to cheese and butter, there were studies showing a deleterious effect, but the grade of evidence was weak. Further mechanistic studies combined with large prospective studies and RCTs in ethnically diverse populations, taking into account sufficient dose and duration, are warranted to get a more complete understanding of dairy consumption and T2D risk
How did it happen? The development and redevelopment of Huntley & Palmers biscuit factory (1800-2000)
No full textThis thesis explores the development and redevelopment of the Huntley & Palmers
(H&P) Biscuit Factory in Reading (England) between the years 1800 and 2000. In
examining how different theoretical ideas conceptualise property development, it
selects an assemblage lens to explore the available empirical material. This evidence
is ‘cut’ in two different ways: firstly (in Chapter 5) through a linear description of the
various phases of factory development and redevelopment and then (in Chapters 6
and 7) by analysing in a more non-linear way the components and processes of the
H&P factory assemblage.
The research uncovers and explores a range of human and non-human components
having affect on the development and redevelopment processes involved, from
members of the Palmer family to decorated biscuit tins and the persistent risk of fire.
Taking an assemblage view also draws attention to how the H&P factory was shaped
by other assemblages (such as the Great Western Railway, Reading Town and
capitalist market assemblages), which the H&P factory assemblage ‘attached’ itself
to. These components were assembled to achieve an evolving set of desires centred
around the mechanisation, modernisation and automation of biscuit making.
Processes of territorialisation, deterritorialisation and reterritorialisation are
identified and evaluated while patterns of coding are linked to the power relations
embedded in, and articulated through, the assemblage.
The thesis concludes by responding the question set in the thesis title and suggests
that the H&P biscuit factory was assembled and re-assembled through a
combination of processes operating in relation to a multiplicity of heterogeneous
components. The research undertaken confirms the potentialities of assemblage
theory for the analysis (and positive shaping) of urban change but raises questions
that could be addressed by future research
Mangosteen (Garcinia mangostana) pericarp and leaf tinctures Inhibit LPS-induced pro-inflammatory responses in macrophages and activate Nrf2
No full textBackground/Objectives: Xanthones from the tropical fruit mangosteen (Garcinia mangostana) have been reported to modulate oxidative stress and inflammatory responses. This work explored the anti-inflammatory potential of mangosteen in the form of tinctures. Methods: Tinctures were prepared from the pericarp and leaves, characterized for their major constituents, and evaluated for their in vitro, anti-inflammatory and antioxidant potential. Results: HPLC analysis revealed eight major isoprenylated xanthones whose concentrations increased with an increasing alcohol percentage. α-Mangostin and γ-mangostin, two major xanthones present in the tinctures, were stable for 12 weeks at room and elevated (40 °C) temperatures, indicating stability of the tincture. In vitro luciferase reporter assays using HepG2-ARE revealed an alcohol concentration-dependent activation of Nrf2 by pericarp and leaf tinctures. The tinctures inhibited lipopolysaccharide (LPS)-induced production of nitric oxide (NO) and reactive oxygen species (ROS) in RAW264.7 cells. Garcinone C (GarC) and garcinone D (GarD) caused significant inhibition of LPS-induced NO production and iNOS expression. GarC and GarD also induced nuclear translocation of Nrf2 and upregulated heme oxygenase 1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1), and glutathione S-transferase Pi 1 (GSTP1) in RAW264.7 cells. Conclusions: Taken together, mangosteen tinctures are a significant source of prenylated xanthones with anti-inflammatory and antioxidant potential
Cultural tightness-looseness and international expansion of emerging market firms: a cultural escapism perspective
Full text linkDrawing on cultural tightness–looseness theory and institutional escapism view, this study develops a cultural escapism perspective to examine the impact of within-country cultural heterogeneity in emerging market context, specifically subnational cultural tightness–looseness, on firms’ outward foreign direct investment. Tight culture is characterized by strict social norms with low tolerance for deviant behaviors within a society. This study examines how emerging market firms navigate the constraints of cultural tightness through internationalization, such that firms located in culturally tight regions are more likely to engage in international expansion. In addition, the strength of the relationship between cultural tightness and a firm’s international expansion is contingent on government R&D subsidies and industry technological dynamism. The hypotheses are tested and supported through an analysis of Chinese listed firms during the period of 2007 to 2019. The cultural escapism perspective contributes to cultural tightness–looseness theory and international business research
Molecular analysis of how iron regime impacts ferritin A levels post-transcriptionally in E. coli
No full textIron-storage proteins are key components of iron homeostasis. In Escherichia coli, iron
is mainly stored by ferritin A (FtnA) to support growth under iron restriction. Although the
process of FtnA iron uptake is well understood, mechanisms of iron release remain unclear.
This study aimed to investigate the possible mechanisms that control FtnA stability and
degradation, the potential role of the FtsH protease in the regulation of FtnA levels and the
possibility that FtsH targets FtnA for degradation through the “N-end rule”. Furthermore, the
impact of ftnA expression from a surrogate promoter on FtnA regulation was considered in
order to divorce transcriptional effects from those imposed post-transcriptionally. In particular,
an aim was to determine whether the increased levels of FtnA caused by an L2A/K mutation
are post-transcriptionally mediated.
Proteins with primary-destabilising second residues, such as FtnA, are less stable and
can be targeted by proteases via the N-end rule; replacement with stabilising residues can
elevate protein levels. A previous study showed that substitution of the conserved Leu2 of FtnA
with Lys or Ala caused a major increase in FtnA levels, and the basis of this effect was explored
here. An inducible promoter was used to drive expression of wildtype and L2A/K ftnA in
mutants lacking iron-storage genes (ftnA, bfr and dps). Plasmid-dependent wildtype FtnA
showed an average 3.9-fold increase in response to iron supplementation in stationary phase,
and FtnA-L2A/K variants resulted in ~1.5-fold increased growth under iron restriction and
much higher FtnA levels compared to the wildtype version (confirming pervious data),
suggesting that the N-terminal sequence strongly influences FtnA stability and that Leu2
mediates rapid turnover. Whole-cell ICP-OES revealed an average 14.6% increase in iron for
L2 variants, consistent with enhanced growth observed as a result of the increased FtnA iron-storage capacity for the L2 variants.
A previous study demonstrated a potential role for FtsH in control of FtnA levels from
chromosomally-encoded FtnA, and this was confirmed here: a ∆ftsH mutant showed a
reproducible 3.9-fold increase in FtnA accumulation during exponential growth in response to
iron. However, when ∆ftsH was introduced into a strain lacking the three iron-storage proteins
and complemented with inducible ftnA (WT, L2A, L2K) from pBADrha, FtnA levels were
indistinguishable with or without FtsH. This indicates that FtsH regulates FtnA mainly via
effects on the native ftnA promoter not direct proteolysis (as was previously considered), and
that L2A/K impacts on FtnA levels are FtsH-independent. Thus, subsequent investigation was
aimed at assessing how the expression context of ftnA impacted its regulation. Therefore, the
role of H-NS was examined. H-NS, known to repress chromosomal ftnA (relieved by Fe²⁺-Fur),
was found instead to activate plasmid-dependent ftnA, likely through control of Prha1, with
effects observed at both protein and transcript levels. RhaSR-regulated rhaT and Prha1
transcripts were also H-NS induced, suggesting that the Rha regulon is H-NS activated.
Moreover, qRT-PCR showed no significant changes in plasmid-dependent ftnA transcript levels
for L2 variants, confirming that elevated FtnA-L2A/K arises post-transcriptionally possibly via
increased FtnA stability (reduced degradation). Such turnover may play an important role in
regulating E. coli iron-storage capacity and mediating release of iron from stores
Energy transitions in Sub-Saharan Africa: policy recommendations for charcoal trade, solar PV adoption, and sustainability in rural Zambia
Full text linkA systematic review of antimicrobial stewardship practices and challenges in sub-Sahara Africa (SSA) regulated retail medicine settings.
No full textAim: This systematic review examined the practices and challenges of implementing antimicrobial stewardship (AMS) in sub-Sahara Africa (SSA) regulated retail medicine settings.
Methods: We searched studies published between January 1, 2010, and July 30, 2024, from PubMed, Web of Science, ProQuest Central, Google Scholar, African Journals Online, and Wiley Online Library. We also reviewed reference lists of studies included in the review. The included studies were quality-assessed using the Mixed Method Appraisal Tool, with data analysed thematically. The protocol was registered in the International Prospective Register for Systematic Reviews (PROSPERO), registration number CRD42023381320.
Results: Of the 2,555 screened studies, 26 met the inclusion criteria; eight qualitative, 16 quantitative and two mixed methods . Community pharmacists, accredited drug dispensers, and patent medicine vendors were reported to be aware of antimicrobial resistance (AMR) and AMS. Across studies with extractable numeric data (n = 10), the median prevalence of non-prescription antibiotic dispensing was 67.5% (IQR: 52.5–84.9%), indicating that the practice is widespread in sub-Saharan Africa. However, few studies documented AMS activities that have taken place. Reported barriers to AMS included non-prescription antibiotic dispensing, weak regulation, and economic pressures despite knowledge of antibiotics, antibiotic resistance and the importance of AMS.
Conclusion: Our study revealed limited data on AMS implementation in SSA-regulated retail medicine settings. Despite self-reported awareness of AMR, AMS efforts are hindered by systemic challenges such as economic constraints, weak regulatory enforcement, and systemic barriers. Strengthening regulations, public awareness, and multi-stakeholder collaboration is critical to improving AMS in SSA retail medicine settings