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The goal of this study was to evaluate the age-differentiated health risks associated with exposure to mercury in drinking water from artisanal small-scale gold mining (ASGM) sites on nearby communities in Yolombo, Colombia. In 2017, nine samples were collected from a local regulatory agency to report mercury concentrations in locations near mining sites. We performed a risk assessment to find 100% of the water samples collected downstream of mining sites exceed Hazard Quotient (HQ) risk thresholds (set by the US-Environmental Protection Agency and Health Canada). HQ model, coupled with global sensitivity and uncertainty analysis (GSUA), was used to conclude infants as the most vulnerable, with 50% of the population exceeding HQ thresholds. Length of exposure was the most significant input that contributed to risk variance, explaining 30-55% of risk across all age groups. Monte-Carlo filtering was used to identify effective strategies to reduce the number of individuals exceeding allowable HQ thresholds. After Monte-Carlo filtering intervention strategies, all individuals are below HQ thresholds. This work shows the importance of combining risk assessment tools with sensor data to inform the need for filters, stakeholder education, and alternative mining approaches to gain a multi-perspective risk approach. This work provides a valuable risk and decision modeling methodology and baseline information to gain a deeper understanding of the probability of experiencing detrimental health effects from water contamination in ASGM communities. [ABSTRACT FROM AUTHOR]

The papaya mealybug, Paracoccus marginatus Williams and Granara de Willing (Coccomorpha: Pseudococcidae), is a polyphagous pest that damages many tropical crops. It is native to Central America and spread to the Caribbean region and South America in the 1900s. Since then, it has accidentally been introduced to several islands in the Pacific region and some countries in Africa and Asia. The first record of this mealybug in Polynesia was in Hawaii, in 2004. This paper presents the first report of this pest in Tahiti (French Polynesia), where it was found in March 2017 on papaya (Carica papaya) and frangipani trees (Plumeria spp.). Its presence, which is mainly in the inhabited part of the island of Tahiti, suggests the recent introduction of the pest in French Polynesia. Several coccinellid predators have been found feeding on the mealybug in Tahiti: Cryptolaemus montrouzieri, Hyperaspis pantherina and Scymnus spp. None of its parasitoids have been found yet. [ABSTRACT FROM AUTHOR]

Dielectric relaxation spectroscopy (10[sup -1]Hz to 10[sup 6] Hz) is employed to study the molecular dynamics of poly(dimethylsiloxane) (PDMS, M[sub w] = 1.7 × 10[sup 5] g mol[sup -1] and M[sub w] = 9.6 × 10[sup 4] g mol[sup -1]) as grafted films with thicknesses d below and above the radius of gyration R[sub g]. For the thinnest films the molecular dynamics becomes faster by up to two orders of magnitude with respect to the bulk resulting in a pronounced decrease of the Vogel temperature TO and hence the calorimetric glass transition temperature T[sub g]. For films with d= 41 nm>R[sub g] the molecular dynamics is comparable to that of the bulk melt. The results are interpreted in terms of a chain confinement effect and compared with findings for low molecular weight glass forming liquids contained in nanoporous materials. Crystallization effects—well known for PDMS—are observed for films of thicknesses above and below R[sub g]. [ABSTRACT FROM AUTHOR]

We give a closed form evaluation of the zeta determinant of the Laplace operator on spheres and projective spaces that clearly describes the arithmetic structure of this number. All the factors in the final formula for the determinant are easily computable. [ABSTRACT FROM AUTHOR]

The Neoproterozoic geotectonic triad of the Brasiliano Orogen is reconstructed in southern Brazil from studies focused on the Porongos fold and thrust belt. We integrate field geology with isotopic studies of zircon U–Pb SHRIMP and Lu–Hf–O laser determinations in seven metasedimentary and three metavolcanic rock samples. The results indicate that the Porongos palaeo-basin was derived from mixed sources (3200–550 Ma), with major contributions from Rhyacian (2170 Ma) and Ediacaran (608 Ma) sources. Minor contributions from Archaean to Tonian sources are also registered. The maximum depositional age of the Porongos palaeo-basin is established by the age range of 650–550 Ma withTDMmodel ages between 2.5 and 1.3 Ga. The reworked signature (εHfvalues = −34 to −4) and the characteristic crustal magma reservoirs (δ18O ≥5.3 ‰) indicate that these sediments are equivalent to Neoproterozoic granites of the Dom Feliciano Belt. The episodic depositional history started in the Cryogenian (650 Ma) and lasted until the Ediacaran (most likely 570 Ma). A magmatic event of Tonian age is recorded in rhyodacite samples interleaved with the metasedimentary rocks and dated at 773, 801, and 809 Ma. The crustal evolution of the Sul-Riograndense Shield included mountain building, folding and thrusting and flexural subsidence in the foreland. An orogenic triad is revealed as the Pelotas Batholith, the Porongos fold and thrust belt and the Camaquã Basin, all part of the Dom Feliciano Belt. [ABSTRACT FROM PUBLISHER]

The Serra Geral Group has high Cu concentrations in southern Brazil, including the Realeza (Paraná) region where Au and Ag also occur. The basalts (46.7-50.8 wt.% SiO2) have breccias at the top of 10 out of 31 studied flows in the Realeza section and at the top of 5 out of 7 analyzed flows in the Capanema section. Sand injectites occur at the top of basalts in 18 out of 23 flows from the Realeza section. The average content of Cu in three samples of mineralized breccias is 3788 ppm. One sample from a silicified sandstone sill intruded at the top of a basalt flow has up to 0.66 ppm Au. K2O was not leached during basalt alteration. The hydrothermal breccias, particularly when sand is present, show enrichment in U which leads to higher values of scintillometry (rate of emission of K, U and Th). In the basalts, breccias and sandstones, Pd (17.5 ± 8.4 ppb) is higher than Pt (12.5 ± 5 ppb), suggesting a hydrothermal remobilization of the metals. The Serra Geral Group is thus shown to have high potential for precious and base metal deposits. [ABSTRACT FROM AUTHOR]

A comparison of accretion and (turbulent) magnetic diffusion time-scales for sheets and filaments demonstrates that dense star-forming clouds generally will – under realistic conditions – become supercritical due to mass accretion on time-scales at least an order of magnitude shorter than ambipolar and/or turbulent diffusion time-scales. Thus, ambipolar or turbulent diffusion – while present – is unlikely to control the formation of cores and stars. [ABSTRACT FROM PUBLISHER]

Abstract: The aim of this study was to investigate biological effects and potential health risks due to two different metal-inert-gas (MIG) welding fumes (MIG welding of aluminium and MIG soldering of zinc coated steel) in healthy humans. In a threefold cross-over design study 12 male subjects were exposed to three different exposure scenarios. Exposures were performed under controlled conditions in the Aachener Workplace Simulation Laboratory (AWSL). On three different days the subjects were either exposed to filtered ambient air, to welding fumes from MIG welding of aluminium, or to fumes from MIG soldering of zinc coated materials. Exposure was performed for 6h and the average fume concentration was 2.5mgm−3. Before, directly after, 1 day after, and 7 days after exposure spirometric and impulse oscillometric measurements were performed, exhaled breath condensate (EBC) was collected and blood samples were taken and analyzed for inflammatory markers. During MIG welding of aluminium high ozone concentrations (up to 250μgm−3) were observed, whereas ozone was negligible for MIG soldering. For MIG soldering, concentrations of high-sensitivity CRP (hsCRP) and factor VIII were significantly increased but remained mostly within the normal range. The concentration of neutrophils increased in tendency. For MIG welding of aluminium, the lung function showed significant decreases in Peak Expiratory Flow (PEF) and Mean Expiratory Flow at 75% vital capacity (MEF 75) 7 days after exposure. The concentration of ristocetin cofactor was increased. The observed increase of hsCRP during MIG-soldering can be understood as an indicator for asymptomatic systemic inflammation probably due to zinc (zinc concentration 1.5mgm−3). The change in lung function observed after MIG welding of aluminium may be attributed to ozone inhalation, although the late response (7 days after exposure) is surprising. [Copyright &y& Elsevier]

The capability of determining the flow-by-flow stratigraphy and the long-distance correlation of lava flows in large continental volcanic provinces leads to a considerable advance in the understanding of processes related to generation and evolution of the lavas. The Paraná volcanic province is exposed along the Serra Geral cuesta of southern Brazil in a steeply inclined, 1,000-m-high section starting 40-m above sea level. Each of the 10-20 pahoehoe flows and rhyodacite flow units has a unique chemical composition. Integrated with field stratigraphy and gamma-spectrometric measurements, this leads to the establishment of the correct stratigraphic sequence in each of three different vertical sections. The number of flows integrating the three serras is 26 ('serra' is a mountain range in Portuguese). Each serra has basaltic andesites at the base, whereas rhyodacites are intercalated with basaltic andesites at the top. Three basaltic andesite flows and one rhyodacite flow unit are correlated between Serra Umbu and Serra Boa Vista (10 km). In the Serra Faxinal, a thick (170 m) sill at the base correlates with flow 13F, whereas a dike-sill in the Graxaim quarry (24 km distance) correlates with flow 3F. One basaltic andesite and two rhyodacite flow units correlate between Serra Faxinal and Serra Umbu (50 km). The results are most significant for the understanding of large tracts of continental volcanic provinces with use of common geochemical and gamma-spectrometric techniques. [ABSTRACT FROM AUTHOR]

Numerical modelling by finite element methods provides two significant insights into the formation of the giant amethyst geodes of the Paraná volcanic province: the conditions needed to open the cavities and the conditions that control their size and shape. Giant amethyst geodes were formed in the Cretaceous (135 Ma) in altered volcanic rocks by water vapour pressure (Δp) at about 0.5 MPa under an altered basalt cover of 5-20 m. Only rocks with Young's modulus values (E) in the range 1-2 GPa can sustain ballooning, which is the growth of a cavity in a ductile medium by the pressure of water and its vapour. The size of the proto-geode is dependent on the water vapour pressure, which is directly related to thickness of the overlying basalt. Varying the yield points causes the formation of either prolate or oblate cavities. A low transition point (smaller than 0.18 MPa) generates a prolate-shaped cavity, whereas a high transition point (larger than 0.18 MPa) generates oblate proto-geodes. Proto-geodes are smaller when Young's modulus is higher (rock is less altered) or when water vapour pressure is lower (because of thinner overburden of basalt). The calculations are an indication that the processes operative in the altered basalts led to the opening of giant cavities by ballooning. [ABSTRACT FROM AUTHOR]

Abstract: We study the analytic torsion of a cone over an orientable odd dimensional compact connected Riemannian manifold . We prove that the logarithm of the analytic torsion of the cone decomposes as the sum of the logarithm of the root of the analytic torsion of the boundary of the cone, plus a topological term, plus a further term that is a rational linear combination of local Riemannian invariants of the boundary. We show that this last term coincides with the anomaly boundary term appearing in the Cheeger Müller theorem for a manifold with boundary, according to Brüning and Ma (2006) . We also prove Poincaré duality for the analytic torsion of a cone. [ABSTRACT FROM AUTHOR]

Abstract: We compute the analytic torsion of a cone over a sphere of dimensions 1, 2, and 3, and we conjecture a general formula for the cone over an odd dimensional sphere. [Copyright &y& Elsevier]

Abstract: The molecular dynamics in thin films of isotactic poly(methylmethacrylate) is investigated by broadband dielectric spectroscopy. No shifts in the mean relaxation time of the dynamic glass transition are detected down to a film thickness of 6.6nm. These results are compared to previous measurements on thin films of isotactic poly(methylmethacrylate) [L. Hartmann et al., Eur. Phys. J. E 8 (2002) 145]. We show that in the latter case, the shifts in the dynamic glass transition are caused by an erroneous analysis of the experimental results. [Copyright &y& Elsevier]

We study the dynamics of entanglement in spin gases. A spin gas consists of a (large) number of interacting particles whose random motion is described classically while their internal degrees of freedom are described quantum-mechanically. We determine the entanglement that occurs naturally in such systems for specific types of quantum interactions. At the same time, these systems provide microscopic models for non–Markovian decoherence: the interaction of a group of particles with other particles belonging to a background gas are treated exactly, and differences between collective and non–collective decoherence processes are studied. We give quantitative results for the Boltzmann gas and also for a lattice gas, which could be realized by neutral atoms hopping in an optical lattice. These models can be simulated efficiently for systems of mesoscopic sizes (N ~ 105). [ABSTRACT FROM AUTHOR]

Quantum mechanical entanglement can exist in noisy open quantum systems at high temperature. A simple mechanism, where system particles are randomly reset to some standard initial state, can counteract the deteriorating effect of decoherence, resulting in an entangled steady state far from thermodynamical equilibrium. We present models for both gas-type systems and for strongly coupled systems. We point out in which way the entanglement resulting from such a reset mechanism is different from the entanglement that one can find in thermal states. We develop master equations to describe the system and its interaction with an environment, study toy models with two particles (qubits), where the master equation can often be solved analytically, and finally examine larger systems with possibly fluctuating particle numbers. We find that in gas-type systems, the reset mechanism can produce an entangled steady state for an arbitrary temperature of the environment, while this is not true in strongly coupled systems. But even then the temperature range where one can find entangled steady states is typically much higher with the reset mechanism. [ABSTRACT FROM AUTHOR]

We estimate the levels of turbulence in the envelopes of class 0 and I protostars using a model based on measurements of the peak separation of double-peaked asymmetric line profiles. We use observations of 20 protostars of both class 0 and I taken in theline that show the classic double-peaked profile. We find that some class 0 sources show high levels of turbulence, whilst others demonstrate much lower levels. In class I protostars, we find predominantly low levels of turbulence. The observations are consistent with a scenario in which class 0 protostars form in a variety of environments and subsequently evolve into class I protostars. The data do not appear to be consistent with a recently proposed scenario in which class 0 protostars can only form in extreme environments. [ABSTRACT FROM AUTHOR]

The biochemical modification of the metals and metalloids mercury, tin, arsenic, antimony, bismuth, selenium, and tellurium via formation of volatile metal hydrides and alkylated species (volatile and involatile) performs a fundamental role in determining the environmental processing of these elements. In most instances, the formation of such species increases the environmental mobility of the element, and can result in bioaccumulation in lipophilic environments. While inorganic forms of most of these compounds are well characterized (e.g., arsenic, mercury) and some of them exhibit low toxicity (e.g., tin, bismuth), the more lipid-soluble organometals can be highly toxic. Methylmercury poisoning (e.g., Minamata disease) and tumor development in rats after exposure to dimethylarsinic acid or tributyltin oxide are just some examples. Data on the genotoxicity (and the neurotoxicity) as well as the mechanisms of cellular action of organometal(loid) compounds are, however, scarce. Many studies have shown that the production of such organometal(loid) species is possible and likely whenever anaerobic conditions (at least on a microscale) are combined with available metal(loid)s and methyl donors in the presence of suitable organisms. Such anaerobic conditions can exist within natural environments (e.g., wetlands, pond sediments) as well as within anthropogenic environmental systems (e.g., waste disposal sites and sewage treatments plants). Some methylation can also take place under aerobic conditions. This article gives an overview about the environmental distribution of organometal(loid) compounds and the potential hazardous effects on animal and human health. Genotoxic effects in vivo and in vitro in particular are discussed. [ABSTRACT FROM AUTHOR]

Broadband Dielectric Spectroscopy is employed to study the molecular dynamics in thin layers of grafted and spin-coated polydimethylsiloxane (PDMS) and of the type-A polymer cis-1,4-polyisoprene (PI). Strong resemblance with low-molecular-weight systems is found but additionally the conformation of the chain and its extension becomes important. For PI a confinement-induced relaxation is found. It is observable if the layer thickness is comparable to the end-to-end vector of the chain and it depends strongly on the separation between interfaces. In contrast, the dynamic (and hence the calorimetric) glass transition is not affected by the geometrical confinement. [ABSTRACT FROM AUTHOR]

The separation of the evaporation from the high-temperature reaction zone is crucial for the reforming process. Unfavorable mixtures of liquid fuels, water and air lead to degradation by local hot spots in the sensitive catalysts and formation of unwanted by-products in the reformer. Furthermore, the evaporator has to work with dynamic changes in the heat transfer, residence times and educt compositions. By using exothermal pre-reactions in the form of cool flames it is possible to realize a complete and residue-free evaporation of liquid hydrocarbon mixtures. The conditions whether cool flames can be stabilised or not is related to the heat release of the pre-reactions in comparison to the heat losses of the system.Examinations were conducted in a flow reactor at atmospheric pressure and changing residence times to investigate the conditions under which stable cool flame operation is possible and auto-ignition or quenching occurs. An energy balance of the evaporator should deliver the values of heat release by cool flames in comparison to the heat losses of the system.The cool flame evaporation is applied in the design of several diesel-reforming processes (thermal and catalytic partial oxidation, autothermal reforming) with different demands in the heat management and operation range (air ratio λ, steam-to-carbon ratio, SCR). The results are discussed at the end of this paper. [Copyright &y& Elsevier]

Describes a novel experimental approach based on the use of solid electrodes to prepare capacitor arrangements with a thickness in the order of 10nm containing layers of grafted polymers. Significance of dielectric spectroscopy in probing the dynamics; Difference between the bulk and the grafted layer; Illustration of the relaxation strength of the side chain fluctuation for the grafted layer.

This review describes various in vivo animal models (humans; conventional animals administered antimicrobial agents and animals species used; gnotobiotic and germ-free animals), in vitro models (luminal and mucosal), and in silico and mathematical models which have been developed to study colonisation and colonisation resistance and effects of gut flora on hosts. Where applicable, the advantages and disadvantages of each model are discussed. [ABSTRACT FROM AUTHOR]

By use of external periodic driving sources, we demonstrate the possibility of controlling the coherent as well as the decoherent dynamics of a two-level atom placed in a lossy cavity. The control of the coherent dynamics is elucidated for the phenomenon of coherent destruction of tunnelling (CDT), i.e. the coherent dynamics of a driven two-level atom in a quantum superposition state can be brought practically to a complete standstill. We study this phenomenon for different initial preparations of the two-level atom. We then proceed to investigate the decoherence originating from the interaction of the two-level atom with a lossy cavity mode. The loss mechanism is described in terms of a microscopic model that couples the cavity mode to a bath of harmonic field modes. A suitably tuned external cw-laser field applied to the two-level atom slows down considerably the decoherence of the atom. We demonstrate the suppression of decoherence for two opposite initial preparations of the atomic state: a quantum superposition state as well as the ground state. These findings can be used to decrease the influence of decoherence in qubit manipulation processes. [ABSTRACT FROM AUTHOR]

Significant improvements, both in understanding the evolution of zircons and in understanding the geotectonic and metallogenetic evolution of the complex terrain of southern Brazil, are obtained from a SHRIMP geochronology study and reviewed in this paper. The use of backscattered electron and cathodoluminescence images, prior to SHRIMP isotopic determinations, proved of enormous fundamental value for this technique. Zircon is a domainal open-system mineral in many geological conditions; very old domains may be preserved, but the same crystal may show ages of younger tectonic events. Zircons may recrystallise inwards from the rims or outwards from the cores, and also along euhedral high-U or metamict thin zones. Zircons also may be recrystallised during gold-related hydrothermalism, phyllic alteration of granitic rocks. The precise dating of amphibolite dykes can be achieved by the identification and dating of magmatic zircons. Precambrian orogenies are identified along with the intervening intracratonic tectonic cycles of supercontinents in southern Brazil from 3300 to 470 Ma. Granulite protoliths were formed during the Jequié Orogeny (ca 2600 Ma), but extensive arc accretion occurred in the Palaeoproterozoic (ca 2250 Ma) Encantadas Orogeny. Late in the Transamazonian Cycle, granites were formed by crustal melting at about 2000 Ma in the Camboriú Orogeny. Both accretionary and collisional orogenies are also identified in the Neoproterozoic Brasiliano Cycle. These are the accretionary Passinho Orogeny (ca 900 Ma) and São Gabriel Orogeny (ca 700 Ma), that were succeeded by the collisional Dom Feliciano Orogeny (ca 600 Ma). Base-metal and gold deposition occurred in juvenile island arcs and in late orogenic porphyry-copper-type magmatic–hydrothermal settings during the Neoproterozoic. [ABSTRACT FROM AUTHOR]

Purpose: The increasing incidence and biological heterogeneity of ductal carcinoma in situ (DCIS) of the breast have made the management of this entity challenging and controversial. This paper reviews data on the natural history of the disease and results obtained with various management approaches.Data Sources: Computerized MEDLINE search of articles related to DCIS published since 1966.Study Selection: Randomized trials were given higher value; however, because these were relatively scarce, retrospective studies and data published in abstract form were also included.Data Extraction: The authors reviewed all sources critically. No formal statistical calculations were made.Data Synthesis: The incidence of DCIS is increasing, and a greater proportion of diagnoses are being made in asymptomatic patients. No data from randomized trials compare mastectomy and breast-conserving therapy for the treatment of DCIS. A large randomized trial comparing lumpectomy with lumpectomy plus radiotherapy showed lumpectomy plus radiotherapy to be effective for management of this disease. The presence of comedo necrosis and surgical margin status are frequently used as predictors of subsequent recurrence, although this practice is controversial. The risk for in-breast recurrence at 5 years after lumpectomy and radiotherapy is approximately 8%. With more refined molecular analysis, the relation of DCIS to invasive breast cancer will be better defined.Conclusions: Treatment strategies for DCIS have evolved, and lumpectomy followed by radiotherapy is an appropriate alternative for most patients. The use of lumpectomy alone in selected patients remains controversial. [ABSTRACT FROM AUTHOR]

We present a homological version of the Inverse Mapping Theorem for open and discrete continuous maps between oriented topological manifolds, with assumptions on the degree of the maps, but without any assumption on differentiability. We prove that this theorem is equivalent to the known homological version of the Implicit Mapping Theorem. Additionally, we study conditions for a map between oriented topological manifolds to be locally like an injection or a projection, via alternative notions of topological immersions and submersions. [ABSTRACT FROM AUTHOR]

Examines new indications of the importance of spatially-resolved observations of stellar winds in elucidating the mechanisms of mass ejection. `Wolf-Rayet' star; Features.

Background: The objective of the study was to evaluate completion rates and toxic effects of an i.p. chemotherapy regimen in a cross-section of nonselected patients with ovarian cancer (OC). Patients and methods: All patients with stage IIIC OC consecutively operated at our institution from January 2006 to December 2007 were prospectively collected and analyzed. Results: Eighty-nine patients with stage IIIC OC optimally debulked were evaluated for this study. An i.p. port was primarily placed in 53 of 89 (60%), and i.p. chemotherapy was recommended in 55 patients. Reasons for not recommending i.p. chemotherapy in patients optimally debulked included postoperative complications (n = 7: 8%), poor nutritional/functional status (n = 5: 6%), and extensive surgery including bowel resection (n = 9: 10%). Thirty-three patients (33/55: 60%) recommended to receive i.p. chemotherapy-initiated i.p. treatment. Fifty-two percent of those beginning i.p. therapy (17/33) received three or more cycles with 36% (12/33) successfully completing six cycles. Reasons for discontinuation included grade 3-4 nephrotoxicity in 3 of 21 (14%), febrile neutropenia/sepsis in 3 of 21 (14%), port infection or malfunction in 8 of 21 (38%). Conclusions: The i.p. chemotherapy regimen used in a consecutive cohort of patients carries could be completed in only a small percentage of patients. Less toxic regimens with higher acceptability should be considered. [ABSTRACT FROM AUTHOR]

The SW--NE-striking Porongos belt, located between juvenile Neoproterozoic rocks in the west and the Dora Feliciano belt, characterized by intense reworking of older crust, in the east. comprises a greenschist to amphibolite-facies metavolcano-metasedimentary succession (Porongos sequence) of unknown age with some exposures of Palaeoproterozoic gneisses (Encantadas gneisses). High-temperature ductile deformation of the basement gneisses comprises at least two magmatic events followed by three deformational phases including folding and shearing (DT1-DT3) and can be attributed to the Palaeoproterozoic Trans-Amazonian orogeny. The deformation of the Porongos sequence occurred during the Neoprnterozoic Brasiliano orogeny and comprises four ductile deformation phases (DB1-DB4), including two phases of isoclinal folding associated with shearing recorded in mylonitic layers, followed by closed NW-vergent folding and thrusting leading to formation of a thrust stack. Uplift of the basement and formation of late tectonic sedimentary basins occurred as a result of semi-ductile to brittle block faulting in a sinistral strike-slip regime. The Porongos sequence can be subdivided into a southeastern and a northwestern part. Trace element analyses as well as Sm--Nd and Rb--Sr geochemical data indicate partial melting and significant contamination by old continental crust for the metavolcanic rocks. The metavolcanic rocks show εNd(t = 780 Ma) values of 20.64 and -21.72 (northwestern units) and -6.87 (southeastern sequence). The metasedimentary rocks were derived from late Palaeoproterozoic to Archaean sources, and the data indicate different sources for the northwestern and southeastern rock units of the Porongos sequence. εNd(t = 780 Ma) are -6.25 and 6.85 in the southeastern units, with TDM model ages between 1734 and 1954 Ma, and vary between -14.72 and -17.96 in the northwestern parts, which have TDM model ages between 2346 and 2710 Ma. High 87Sr/86Sr(t) values between 0.7064 and 0.7286 confirm reworking of older crust. Isotopic signatures of the Porongos sequence do not show indications for a significant contribution from a Neoproterozoic juvenile source. A passive margin or continental rift environment is suggested for the tectonic setting of the Porongos belt, which is compatible with both deposition of shallow marine to deep marine sediments and stretching of continental crust leading to volcanism which is characterized by significant contamination by old continental crust. [ABSTRACT FROM AUTHOR]

Abstract: Bitelechelic polydimethylsiloxanes (PDMS) and 2-hydroxyethylacrylate (HEA)/acrylic acid(AA) were photopolymerized to give nanophase separated amphiphilic 20-μm-thin coatings covalently attached to glass. The coatings quickly take up the antimicrobial surfactant cetyltrimethylammonium chloride (CTAC). After a 30 min loading period the release of CTAC in water was followed by simultaneously measuring both the antimicrobial activity of the coating''s surface against Staphylococcus aureus and the release of the structurally related dye Rhodamine B. Depending on the composition the antimicrobial activity remained up to 3 weeks. The influence of different pH, varying sodium chloride concentrations, and the surfactant Pluronic was investigated. However, even in the cases of 160 mM NaCl and 1 wt.% Pluronic as release medium, the antimicrobial activity remained more than 6 days in case of a coating consisting of 45 wt.% PDMS, 31 wt.% PHEA, and 25 wt.% PAA. Mechanistic investigations revealed that the CTAC-loaded coatings act like contact-active surfaces, i.e., they do not kill microbes in the surrounding solution but only on their surface. This supports our hypothesis that the antimicrobial action is due to a concentration gradient of CTAC on the surface, allowing it to be antimicrobial on contact and to release only very low concentration of the biocide into the surrounding. [Copyright &y& Elsevier]

Aim: The two bacterial species, Eubacterium ramulus and Enterococcus casseliflavus , which had previously been isolated from human faeces using the flavonoid quercetin-3-glucoside as the growth substrate, were tested for their ability to utilize this compound in vivo . Methods and Results: Germ-free rats were associated with Eu. ramulus and subsequently with Ent. casseliflavus and vice versa. Identification and enumeration of the bacterial cell counts in faeces and intestinal contents were performed by whole cell fluorescence in situ hybridization. Eubacterium ramulus and Ent. casseliflavus occurred in caecal and colonic contents at cell counts of up to 1010 g-1 dry weight. In the jejunum, only Ent. casseliflavus was found (109 g-1 dry weight). Upon oral administration of 32 µmol quercetin-3-glucoside, quercetin was detected in the faeces and urine of germ-free rats (2·2 × 10-1 -8·1 × 10-1 µmol 24-h-1 faeces collection and 1·0 × 10-2 -2·8 × 10-1 µmol 24-h-1 urine collection, respectively) and of rats monoassociated with Ent. casseliflavus (7·9 × 10-1 -2·7 µmol 24-h-1 faeces and 1·0 × 10-1 -5·9 × 10-1 µmol 24-h-1 urine, respectively). In contrast, the faeces and urine of rats associated with Eu. ramulus contained 3,4-dihydroxyphenylacetic acid (4·7 × 10-2 -3·6 µmol 24-h-1 faeces and 2·4 × 10-2 -1·0 µmol 24-h-1 urine, respectively) but only low, or undetectable, concentrations of faecal quercetin (up to 9·3 × 10-2 µmol 24-h-1 faeces; detection limit 2·5 × 10-2 µmol). Urinary quercetin concentrations varied markedly from undetectable amounts up to 1·0... [ABSTRACT FROM AUTHOR]

[Display omitted] • Unraveling the multistage formation mechanism for silver-gold alloy nanoparticles. • Successful mechanistic modeling of a highly complex nanoparticle formation process. • Unprecedented process insights via the calibrated multidimensional population balance equation model. • Determination of material and rate constants, hardly measurable experimentally. The large-scale synthesis of nanoparticles (NPs) with defined properties requires detailed understanding of the underlying formation mechanisms and kinetics. The formation mechanisms of bimetallic NPs are still not sufficiently understood due to the complex reaction chemistry, which makes the control of the supersaturation as the thermodynamic driving force challenging. Particle size, chemical composition, and the distribution of the elements within the particles change dynamically during particle formation. In this work, we propose a mechanism for the formation of bimetallic silver-gold alloy NPs via a green liquid-phase co-reduction synthesis and develop a two-dimensional population balance model to quantitatively describe the evolution of particle size distribution, composition, and optical properties. We shed light on the complex multi-stage formation mechanism of a highly relevant bimetallic NP system, lay the foundation for tailoring the process conditions to achieve targeted optical particle properties and unravel predictive property-process relationships. [ABSTRACT FROM AUTHOR]

Human rights and health care under apartheid in South Africa were studied. Human rights violations, such as detention without charge or trial, assault and torture in police custody, and restriction orders, have had devastating effects on the health of persons experiencing them. These violations have occurred in the context of a deliberate policy of discriminatory health care favoring the white minority over the black majority. South Africa's medical societies have had mixed responses to the health problems raised by human rights violations and inequities in the health care system. The amelioration of health care for all and prevention of human rights violations depend on ending apartheid and discrimination and greater government attention to these problems. [ABSTRACT FROM AUTHOR]

Purpose: In the era of biological therapy of ulcerative colitis (UC), surgical treatment frequently consists of colectomy, end ileostomy, and rectal stump closure before patients go on towards restorative proctocolectomy. We aimed to evaluate possible risk factors for the occurrence of postoperative complications and investigate those after initial colectomy in these patients. Methods: Retrospective analysis of 180 patients (76 female, 104 male) undergoing colectomy for UC with formation of a rectal stump and terminal ileostomy between March 2008 and March 2018 at Charité University Hospital Berlin, Campus Benjamin Franklin. A panel of possible postoperative complications was established, patient history was screened, and postoperative complications were analyzed using the Clavien Dindo Classification. Results: Postoperative complication rate was 27.7%. Mortality was 0.5%. Postoperative ileus occurred in 15.3% and rectal stump leakage in 14.8%. Complications were categorized as Clavien Dindo 3 in 80%. Risk factors for surgical complications after multivariate analysis were ASA classification (p = 0.004), preoperative anemia (Hemoglobin < 8 mg/dl) (p = 0.025), use of immunosuppressants (p = 0.003), more than two cardiovascular diseases (p = 0.016), and peritonitis (p = 0.000). Reoperation rate of patients with surgical complications was 27.7%. Conclusion: Colectomy in high-risk UC patients is associated with significant morbidity. However, most of the surgical complications can be treated conservatively. Overall mortality is low. Patient-related risk factors are associated with postoperative complications. Optimizing these risk factors or earlier indication for surgery in the course of UC may help to reduce morbidity of this procedure. [ABSTRACT FROM AUTHOR]

We investigate the deuteration of methanol towards the high-mass star-forming region NGC 7538-IRS1. We carried out a multi-transition study of CH3OH, 13CH3OH, and the deuterated flavors, CH2DOH and CH3OD, between 1.0 and 1.4 mm with the IRAM-30 m antenna. In total, 34 13CH3OH, 13 CH2DOH lines and 20 CH3OD lines spanning a wide range of upper-state energies (Eup) were detected. From the detected transitions, we estimate that the measured D/H does not exceed 1%, with a measured CH2DOH/CH3OH and CH3OD/CH3OH of about (32 ± 8) × 10−4 and (10 ± 4) × 10−4, respectively. This finding is consistent with the hypothesis of a short-timescale formation during the pre-stellar phase. We find a relative abundance CH2DOH/CH3OD ratio of 3.2 ± 1.5. This result is consistent with a statistical deuteration. We cannot exclude H/D exchanges between water and methanol if water deuteration is of the order 0.1%, as suggested by recent Herschel observations. [ABSTRACT FROM AUTHOR]

Deals with a gynecologic oncology study on the impact of second-look laparotomy on epithelial ovarian cancer. Details of the retrospective review conducted of women with epithelial ovarian cancer; Information on the demographic and pathologic data obtained after the review; Best predictors of survival of patients.

The dust sublimation walls of disks around T Tauri stars represent a directly observable cross-section through the disk atmosphere and midplane. Their emission properties can probe the grain size distribution and composition of the innermost regions of the disk, where terrestrial planets form. Here we calculate the inner dust sublimation wall properties for four classical T Tauri stars with a narrow range of spectral types and inclination angles and a wide range of mass accretion rates to determine the extent to which the walls are radially curved. Best fits to the near- and mid-IR excesses are found for curved, two-layer walls in which the lower layer contains larger, hotter, amorphous pyroxene grains with Mg/(Mg+Fe) = 0.6 and the upper layer contains submicron, cooler, mixed amorphous olivine and forsterite grains. As the mass accretion rates decrease from 10–8 to 10–10M☼ yr–1, the maximum grain size in the lower layer decreases from ∼3 to 0.5 μm. We attribute this to a decrease in fragmentation and turbulent support for micron-sized grains with decreasing viscous heating. The atmosphere of these disks is depleted of dust with dust-gas mass ratios 1 × 10–4 of the interstellar medium (ISM) value, while the midplane is enhanced to eight times the ISM value. For all accretion rates, the wall contributes at least half of the flux in the optically thin 10 μm silicate feature. Finally, we find evidence for an iron gradient in the disk, suggestive of that found in our solar system. [ABSTRACT FROM AUTHOR]

Using NASA Infrared Telescope Facility SpeX data from 0.8 to 4.5µm, we determine self-consistently the stellar properties and excess emission above the photosphere for a sample of classical T Tauri stars (CTTS) in the Taurus molecular cloud with varying degrees of accretion. This process uses a combination of techniques from the recent literature as well as observations of weak-line T Tauri stars to account for the differences in surface gravity and chromospheric activity between the T Tauri stars and dwarfs, which are typically used as photospheric templates for CTTS. Our improved veiling and extinction estimates for our targets allow us to extract flux-calibrated spectra of the excess in the near-infrared.We find that we are able to produce an acceptable parametric fit to the near-infrared excesses using a combination of up to three blackbodies. In half of our sample, two blackbodies at temperatures of 8000 K and 1600 K suffice. These temperatures and the corresponding solid angles are consistent with emission from the accretion shock on the stellar surface and the inner dust sublimation rim of the disk, respectively. In contrast, the other half requires three blackbodies at 8000, 1800, and 800 K, to describe the excess. We interpret the combined two cooler blackbodies as the dust sublimation wall with either a contribution from the disk surface beyond the wall or curvature of the wall itself, neither of which should have single-temperature blackbody emission. In these fits, we find no evidence of a contribution from optically thick gas inside the inner dust rim. [ABSTRACT FROM AUTHOR]

Hydrogels based on nanocomposites of statistical poly(hydroxyethyl acrylate- co-ethyl acrylate) and silica, prepared by simultaneous copolymerization and generation of silica nanoparticles by sol-gel process at various copolymer compositions and silica contents, characterized by a fine dispersion of filler, were investigated with respect to glass transition and polymer dynamics by dielectric techniques. These include thermally stimulated depolarization currents and dielectric relaxation spectroscopy, covering together broad ranges of frequency and temperature. In addition, equilibrium water sorption isotherms were recorded at room temperature (25 °C). Special attention was paid to the investigation of effects of silica on glass transition, polymer dynamics (secondary γ and β relaxations and segmental α relaxation), and electrical conductivity in the dry systems (xerogels) and in the hydrogels at various levels of relative humidity/water content. An overall reduction of molecular mobility is observed in the nanocomposite xerogels, in particular at high silica contents. Analysis of the results and comparison with previous work on similar systems enable to discuss this reduction of molecular mobility in terms of constraints to polymeric motion imposed by interfacial polymer-filler interactions and by the formation of a continuous silica network interpenetrated with the polymer network at filler contents higher than about 15 wt%. [ABSTRACT FROM AUTHOR]