Occurrence and sources of microplastics on Arctic beaches: Svalbard

Plastic pollution is recognised as a major global environmental concern, especially within marine environments. The small size of microplastics (< 5 mm) make them readily available for ingestion by organisms in all trophic levels. Here, four beach sites in Adventfjorden on the west coast of Svalbard, were sampled with the aim of investigating the occurrence and abundance of microplastics on beaches to assess potential sources of microplastic pollution. High variability in microplastic amount, type and polymers were found at all sites ranging from means of 0.7 n/g (number) at the remotest site and 2.2 n/g (number) at the site closest to Longyearbyen. Statistical analyses suggested that patterns observed were linked to direct proximity to human activities through land uses and effluent discharge. These findings point to an increased importance of localised factors on driving elevated microplastic pollution in beach sediments over oceanic controls in remote but inhabited Arctic locations and have important implications for our understanding and future assessments of microplastic pollution in such settings

Selective redox regulation of cytokine receptor signaling by extracellular thioredoxin-1

The thiol-disulfide oxidoreductase thioredoxin-1 (Trx1) is known to be secreted by leukocytes and to exhibit cytokine-like properties. Extracellular effects of Trx1 require a functional active site, suggesting a redox-based mechanism of action. However, specific cell surface proteins and pathways coupling extracellular Trx1 redox activity to cellular responses have not been identified so far. Using a mechanism-based kinetic trapping technique to identify disulfide exchange interactions on the intact surface of living lymphocytes, we found that Trx1 catalytically interacts with a single principal target protein. This target protein was identified as the tumor necrosis factor receptor superfamily member 8 (TNFRSF8/CD30). We demonstrate that the redox interaction is highly specific for both Trx1 and CD30 and that the redox state of CD30 determines its ability to engage the cognate ligand and transduce signals. Furthermore, we confirm that Trx1 affects CD30-dependent changes in lymphocyte effector function. Thus, we conclude that receptor–ligand signaling interactions can be selectively regulated by an extracellular redox catalyst

Separation of Anti-Proliferation and Anti-Apoptotic Functions of Retinoblastoma Protein through Targeted Mutations of Its A/B Domain

BACKGROUND: The human retinoblastoma susceptibility gene encodes a nuclear phosphoprotein RB, which is a negative regulator of cell proliferation. The growth suppression function of RB requires an evolutionarily conserved A/B domain that contains two distinct peptide-binding pockets. At the A/B interface is a binding site for the C-terminal trans-activation domain of E2F. Within the B-domain is a binding site for proteins containing the LxCxE peptide motif. METHODOLOGY/PRINCIPLE FINDINGS: Based on the crystal structure of the A/B domain, we have constructed an RB-K530A/N757F (KN) mutant to disrupt the E2F- and LxCxE-binding pockets. The RB-K530A (K) mutant is sufficient to inactivate the E2F-binding pocket, whereas the RB-N757F (N) mutant is sufficient to inactivate the LxCxE-binding pocket. Each single mutant inhibits cell proliferation, but the RB-KN double mutant is defective in growth suppression. Nevertheless, the RB-KN mutant is capable of reducing etoposide-induced apoptosis. CONCLUSION/SIGNIFICANCE: Previous studies have established that RB-dependent G1-arrest can confer resistance to DNA damage-induced apoptosis. Results from this study demonstrate that RB can also inhibit apoptosis independent of growth suppression

f(R) theories

Over the past decade, f(R) theories have been extensively studied as one of the simplest modifications to General Relativity. In this article we review various applications of f(R) theories to cosmology and gravity - such as inflation, dark energy, local gravity constraints, cosmological perturbations, and spherically symmetric solutions in weak and strong gravitational backgrounds. We present a number of ways to distinguish those theories from General Relativity observationally and experimentally. We also discuss the extension to other modified gravity theories such as Brans-Dicke theory and Gauss-Bonnet gravity, and address models that can satisfy both cosmological and local gravity constraints.Comment: 156 pages, 14 figures, Invited review article in Living Reviews in Relativity, Published version, Comments are welcom

Improvements in vascular health by a low-fat diet, but not a high-fat diet, are mediated by changes in adipocyte biology

<p>Abstract</p> <p>Background</p> <p>Low-fat (LF) and high-fat (HF) weight loss diets improve brachial artery flow-mediated dilation (FMD) in obese individuals, although results are conflicting. Moreover, the role that adipose tissue plays in mediating these diet-related effects are unknown.</p> <p>Objective</p> <p>This study examined how modulations in FMD by HF and LF diets relate to changes in adipocyte parameters.</p> <p>Design</p> <p>Obese subjects (n = 17) were randomized to a HF diet (60% kcal as fat) or a LF diet (25% kcal as fat) for 6 weeks. Both groups were restricted by 25% of energy needs.</p> <p>Results</p> <p>Body weight decreased (<it>P <</it>0.05) in both groups (HF: -6.6 ± 0.5 kg, LF: -4.7 ± 0.6 kg). Fat mass and waist circumference were reduced (<it>P <</it>0.05) in the LF group only (-4.4 ± 0.3 kg; -3.6 ± 0.8 cm, respectively). FMD improved (<it>P <</it>0.05) in the LF group (7.4 ± 0.8% to 9.8 ± 0.8; 32% increase) and was impaired in the HF group (8.5 ± 0.6% to 6.9 ± 0.7; 19% reduction). Increases in plasma adiponectin (<it>P <</it>0.05, 16 ± 5%), and decreases in resistin (<it>P <</it>0.05, -26 ± 11%), were shown by the LF diet only. Greater decreases in leptin were observed with LF (-48 ± 9%) versus HF (-28 ± 12%) (<it>P <</it>0.05, diet × time). Increased FMD by the LF diet was associated with increased adiponectin, and decreased fat mass, waist circumference, leptin, and resistin.</p> <p>Conclusion</p> <p>Beneficial modulations in vascular health by LF diets may be mediated by improvements in adipocyte parameters.</p

Analysis of single nucleotide polymorphism in the promoter and protein expression of the chemokine Eotaxin-1 in colorectal cancer patients

<p>Abstract</p> <p>Background</p> <p>Previous studies suggest that chemokines (chemotactic cytokines) promote and regulate neoplastic progression including metastasis and angiogenesis. The chemokine eotaxin-1 is a powerful eosinophil attractant but also exerts chemotaxis of other leukocytes. Eotaxin-1 has been implicated in gastrointestinal disorders and may play an important role in colorectal mucosal immunity.</p> <p>Patients and methods</p> <p>The objective of this study was to assess the role of eotaxin-1 in colorectal cancer (CRC). Levels of eotaxin-1 protein in CRC tissues (n = 86) and paired normal mucosa were compared after determination by ELISA. Plasma eotaxin-1 levels from CRC patients (n = 67) were also compared with controls (n = 103) using the same method. Moreover, a TaqMan system was used to evaluate the -384A>G eotaxin-1 gene variant in CRC patients (n = 241) and in a control group (n = 253).</p> <p>Results</p> <p>Eotaxin-1 protein levels in colorectal tumours were significantly (P < 0.0001) higher than in normal tissue. Immunohistochemistry revealed eotaxin-1 expression in stromal cells such as fibroblasts and leukocytes of the CRC tissue. The plasma eotaxin-1 level in CRC patients was lower compared with controls (P < 0.0001). Patients with tumours classified as Dukes' stage B and C had lower levels than patients with tumours in Dukes' stage A. We found no difference in genotype distribution but noted a difference regarding allele distribution (P = 0.036) and a dominance of allele G in rectal cancer patients.</p> <p>Conclusion</p> <p>The up-regulated eotaxin-1 protein expression in cancer tissue may reflect an eotaxin-1 mediated angiogenesis and/or a recruitment of leukocytes with potential antitumourigenic role. We noticed a dominance of the G allele in rectal cancer patients compared with colon cancer patients that was independent of eotaxin-1 expression.</p

Diamonds, gold and crime displacement: Hatton Garden, and the evolution of organised crime in the UK

The 2015 Hatton Garden Heist was described as the ‘largest burglary in English legal history’. However, the global attention that this spectacular crime attracted to ‘The Garden’ tended to concentrate upon the value of the stolen goods and the vintage of the burglars. What has been ignored is how the burglary shone a spotlight into Hatton Garden itself, as an area with a unique ‘upperworld’ commercial profile and skills cluster that we identify as an incubator and facilitator for organised crime. The Garden is the UK’s foremost jewellery production and retail centre and this paper seeks to explore how Hatton Garden’s businesses integrated with a fluid criminal population to transition, through hosting lucrative (and bureaucratically complex) VAT gold frauds from 1980 to the early 1990s, to become a major base for sophisticated acquisitive criminal activities. Based on extensive interviews over a thirty year period, evidence from a personal research archive and public records, this paper details a cultural community with a unique criminal profile due to the particularities of its geographical location, ethnic composition, trading culture, skills base and international connections. The processes and structures that facilitate criminal markets are largely under-researched (Antonopoulos et al. 2015: 11), and this paper considers how elements of Hatton Garden’s ‘upperworld’ businesses integrated with project criminals, displaced by policing strategies, to effect this transition

The Dopamine Transporter Gene, a Spectrum of Most Common Risky Behaviors, and the Legal Status of the Behaviors

This study tests the specific hypothesis that the 9R/9R genotype in the VNTR of the dopamine transporter gene (DAT1) exerts a general protective effect against a spectrum of risky behaviors in comparison to the 10R/9R and 10R/10R genotypes, drawing on three-time repeated measures of risky behaviors in adolescence and young adulthood on about 822 non-Hispanic white males from the Add Health study. Our data have established two empirical findings. The first is a protective main effect in the DAT1 gene against risky behaviors. The second finding is that the protective effect varies over age, with the effect prominent at ages when a behavior is illegal and the effect largely vanished at ages when the behavior becomes legal or more socially tolerated. Both the protective main effect and the gene-lifecourse interaction effect are replicated across a spectrum of most common risky behaviors: delinquency, variety of sexual partners, binge drinking, drinking quantity, smoking quantity, smoking frequency, marijuana use, cocaine use, other illegal drug use, and seatbelt non-wearing. We also compared individuals with the protective genotype and individuals without it in terms of age, physical maturity, verbal IQ, GPA, received popularity, sent popularity, church attendance, two biological parents, and parental education. These comparisons indicate that the protective effect of DAT1*9R/9R cannot be explained away by these background characteristics. Our work demonstrates how legal/social contexts can enhance or reduce a genetic effect on risky behaviors

Pervasive melt percolation reactions in ultra-depleted refractory harzburgites at the Mid-Atlantic Ridge, 15° 20′N : ODP Hole 1274A

Author Posting. © The Authors, 2006. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Contributions to Mineralogy and Petrology 153 (2007): 303-319, doi:10.1007/s00410-006-0148-6.ODP Leg 209 Site 1274 mantle peridotites are highly refractory in terms of lack of residual clinopyroxene, olivine Mg# (up to 0.92) and spinel Cr# (~0.5), suggesting high degree of partial melting (>20%). Detailed studies of their microstructures show that they have extensively reacted with a pervading intergranular melt prior to cooling in the lithosphere, leading to crystallization of olivine, clinopyroxene and spinel at the expense of orthopyroxene. The least reacted harzburgites are too rich in orthopyroxene to be simple residues of low-pressure (spinel field) partial melting. Cu-rich sulfides that precipitated with the clinopyroxenes indicate that the intergranular melt was generated by no more than 12% melting of a MORB mantle or by more extensive melting of a clinopyroxene-rich lithology. Rare olivine-rich lherzolitic domains, characterized by relics of coarse clinopyroxenes intergrown with magmatic sulfides, support the second interpretation. Further, coarse and intergranular clinopyroxenes are highly depleted in REE, Zr and Ti. A two-stage partial melting/melt-rock reaction history is proposed, in which initial mantle underwent depletion and refertilization after an earlier high pressure (garnet field) melting event before upwelling and remelting beneath the present-day ridge. The ultra-depleted compositions were acquired through melt re-equilibration with residual harzburgites.Funding for this research was provided by Centre National de la Recherche Scientifique-Institut National des Sciences de l’Univers (Programme Dynamique et Evolution de la Terre Interne)