Early Neoproterozoic limestones from the Gwna Group, Anglesey

Limestone megaclasts up to hundreds of metres in size are present within the Gwna Group mélange, North Wales, UK. The mélange has been interpreted as part of a Peri-Gondwanan fore-arc accretionary complex although the age of deposition remains contentious, proposals ranging from Neoproterozoic to Early Ordovician. This paper uses strontium isotope chemostratigraphy to establish the age of the limestone blocks and thus provide a maximum age constraint on mélange formation. Results show that, although the carbonates are locally dolomitized, primary 87Sr/86Sr ratios can be identified and indicate deposition sometime between the late Tonian and earliest Cryogenian. This age is older than that suggested by stromatolites within the limestone and indicates that the limestone did not form as cap carbonate deposits

Candida species biofilms' antifungal resistance

Candida infections (candidiasis) are the most prevalent opportunistic fungal infection on humans and, as such, a major public health problem. In recent decades, candidiasis has been associated to Candida species other than Candida albicans. Moreover, biofilms have been considered the most prevalent growth form of Candida cells and a strong causative agent of the intensification of antifungal resistance. As yet, no specific resistance factor has been identified as the sole responsible for the increased recalcitrance to antifungal agents exhibited by biofilms. Instead, biofilm antifungal resistance is a complex multifactorial phenomenon, which still remains to be fully elucidated and understood. The different mechanisms, which may be responsible for the intrinsic resistance of Candida species biofilms, include the high density of cells within the biofilm, the growth and nutrient limitation, the effects of the biofilm matrix, the presence of persister cells, the antifungal resistance gene expression and the increase of sterols on the membrane of biofilm cells. Thus, this review intends to provide information on the recent advances about Candida species biofilm antifungal resistance and its implication on intensification of the candidiasis.The authors acknowledge the Fundação para a Ciência e Tecnologia (FCT), Portugal, for supporting Maria Elisa Rodrigues (SFRH/BPD/95401/2013) and Célia F. Rodrigues (SFRH/BD/93078/2013). This study was also supported by the Programa Operacional, Fatores de competitividade—COMPETE and by national funds through FCT—Fundação para a Ciência e a Tecnologia under the scope of the projects FCT PTDC/EBB-EBI/120495/2010 and RECI/EBB-EBI/0179/2012 (FCOM-01-0124-FEDER-027462)

Temporal Trends of Persistent Organic Pollutants across Africa after a Decade of MONET Passive Air Sampling

The Global Monitoring Plan of the Stockholm Convention on Persistent Organic Pollutants (POPs) was established to generate long-term data necessary for evaluating the effectiveness of regulatory measures at a global scale. After a decade of passive air monitoring (2008-2019), MONET is the first network to produce sufficient data for the analysis of long-term temporal trends of POPs in the African atmosphere. This study reports concentrations of 20 POPs (aldrin, chlordane, chlordecone, DDT, dieldrin, endrin, endosulfan, HBCDD, HCB, HCHs, heptachlor, hexabromobiphenyl, mirex, PBDEs, PCBs, PCDDs, PCDFs, PeCB, PFOA, and PFOS) monitored in 9 countries (Congo, Ghana, Ethiopia, Kenya, Mali, Mauritius, Morocco, Nigeria, and Sudan). As of January 1, 2019, concentrations were in the following ranges (pg/m(3)): 0.5-37.7 (Sigma 6PCB), 0.006-0.724 (Sigma 17PCDD/F), 0.05-5.5 (Sigma 9PBDE), 0.6-11.3 (BDE 209), 0.1-1.8 (Sigma 3HBCDD), 1.8-138 (Sigma 6DDT), 0.1-24.3 (Sigma(3)endosulfan), 0.6-14.6 (Sigma 4HCH), 9.1-26.4 (HCB), 13.8-18.2 (PeCB). Temporal trends indicate that concentrations of many POPs (PCBs, DDT, HCHs, endosulfan) have declined significantly over the past 10 years, though the rate was slow at some sites. Concentrations of other POPs such as PCDD/Fs and PBDEs have not changed significantly over the past decade and are in fact increasing at some sites, attributed to the prevalence of open burning of waste (particularly e-waste) across Africa. Modeled airflow back-trajectories suggest that the elevated concentrations at some sites are primarily due to sustained local emissions, while the low concentrations measured at Mt. Kenya represent the continental background level and are primarily influenced by long-range transport

Imprints, Vol. 2

Imprints is the official publication for Sigma Tau Delta, the honorary English fraternity. The editors welcome creative works submitted by contributors and also publish winners of the annual T. E. Ferguson Writing Contest. Especially welcome are poems, fiction pieces and essays of no more than 5,000 words in length. At this time we would like to express our gratitude to David Whitescarver, Sigma Tau Delta faculty advisor, for his unrelenting optimism and valuable help in the preparation of this journal

Regulating, Measuring, and Modeling the Viscoelasticity of Bacterial Biofilms

Biofilms occur in a broad range of environments under heterogeneous physicochemical conditions, such as in bioremediation plants, on surfaces of biomedical implants, and in the lungs of cystic fibrosis patients. In these scenarios, biofilms are subjected to shear forces, but the mechanical integrity of these aggregates often prevents their disruption or dispersal. Biofilms' physical robustness is the result of the multiple biopolymers secreted by constituent microbial cells which are also responsible for numerous biological functions. A better understanding of the role of these biopolymers and their response to dynamic forces is therefore crucial for understanding the interplay between biofilm structure and function. In this paper, we review experimental techniques in rheology, which help quantify the viscoelasticity of biofilms, and modeling approaches from soft matter physics that can assist our understanding of the rheological properties. We describe how these methods could be combined with synthetic biology approaches to control and investigate the effects of secreted polymers on the physical properties of biofilms. We argue that without an integrated approach of the three disciplines, the links between genetics, composition, and interaction of matrix biopolymers and the viscoelastic properties of biofilms will be much harder to uncover

The importance of vulnerable areas with potential tourism development: a case study of the Bohemian forest and South Bohemia tourism regions

The significance of the vulnerability of nature-rich areas with high development potential for tourism was studied using three types of data: 1) spatial distribution of tourist attractions, 2) the appeal level of these attractions, and 3) the number of visitors. The Bohemian Forest and South Bohemia were chosen as study areas. Nine types of landscape spatial appeal were identified in the study area. Two most important types were defined based on their appeal where there are rare relic features in the natural environment dominated by the presence of peat bogs and natural habitats with scrub undergrowth or virgin forests. These types were also found in the areas with the greatest potential for tourism development. However, these areas are also the most important from the point of view of nature conservation and landscape protection in Central Europe

Induction of stable human FOXP3⁺ Tregs by a parasite-derived TGF-β mimic

Immune homeostasis in the intestine is tightly controlled by FOXP3 + regulatory T cells (Tregs), defects of which are linked to the development of chronic conditions, such as inflammatory bowel disease (IBD). As a mechanism of immune evasion, several species of intestinal parasites boost Treg activity. The parasite Heligmosomoides polygyrus is known to secrete a molecule (Hp-TGM) that mimics the ability of TGF-β to induce FOXP3 expression in CD4 + T cells. The study aimed to investigate whether Hp-TGM could induce human FOXP3 + Tregs as a potential therapeutic approach for inflammatory diseases. CD4 + T cells from healthy volunteers were expanded in the presence of Hp-TGM or TGF-β. Treg induction was measured by flow cytometric detection of FOXP3 and other Treg markers, such as CD25 and CTLA-4. Epigenetic changes were detected using ChIP-Seq and pyrosequencing of FOXP3. Treg phenotype stability was assessed following inflammatory cytokine challenge and Treg function was evaluated by cellular co-culture suppression assays and cytometric bead arrays for secreted cytokines. Hp-TGM efficiently induced FOXP3 expression (&gt; 60%), in addition to CD25 and CTLA-4, and caused epigenetic modification of the FOXP3 locus to a greater extent than TGF-β. Hp-TGM-induced Tregs had superior suppressive function compared with TGF-β-induced Tregs, and retained their phenotype following exposure to inflammatory cytokines. Furthermore, Hp-TGM induced a Treg-like phenotype in in vivo differentiated Th1 and Th17 cells, indicating its potential to re-program memory cells to enhance immune tolerance. These data indicate Hp-TGM has potential to be used to generate stable human FOXP3 + Tregs to treat IBD and other inflammatory diseases. </p