2,6-Dimethyl-4-m-tolyl­cyclo­hex-3-enecarboxylic acid

The title compound, C16H20O2, was synthesized to study the hydrogen-bonding inter­action of the two enanti­omers in the solid state. The racemate is made up of carboxylic acid RS dimers. Inter­molecular O—H⋯O hydrogen bonds produce centrosymmetric R 2 2(8) rings which dimerize the two chiral enanti­omers through their carboxyl groups. The chirality of this compound is generated by the presence of the double bond in the cyclo­hexene ring and a chiral axis due to the meta-methyl substituent on the aromatic ring

A hidden alkaline and carbonatite province of early carboniferous age in northeast Poland: Zircon U-Pb and pyrrhotite Re-Os geochronology

Extensive geophysical investigations in NE Poland in the 1950s and 1960s led to the discovery of an alkaline and carbonatite magmatic province buried under thick (600-800 m) Meso-Cenozoic cover north of the Trans-European Suture Zone, or Tornquist Line. Drilling focused on geophysical anomalies identified three intrusions in the Paleoproterozoic metasedimentary and metavolcanic rocks of the Mazowsze Domain: the Pisz gabbro-syenite massif, the Ełk syenite massif, and the small, differentiated Tajno body consisting of clinopyroxenite cumulates and syenites crosscut by carbonatite veins. Emplacement ages for these intrusions have been obtained by (1) zircon U-Pb geochronology on a gabbro from Pisz, a syenite from Ełk, and an albitite from Tajno and (2) a Re-Os model age for pyrrhotite from a Tajno carbonatite. The ages measured by both methods fall in the narrow range 354-345 Ma (Early Carboniferous: Tournaisian). This is slightly younger than the Late Devonian (380-360 Ma) Kola Peninsula alkaline and carbonatite province (20 intrusions) of NW Russia and Karelia but is of comparable age to the first manifestations of the long-lasting (~100 m.yr.) Carboniferous to Permian magmatic event (360-250 Ma) manifest in northern Europe (from the British Isles to southern Scandinavia, the North Sea, and northern Germany) in the foreland of the Variscan orogeny (in the so-called West European Carboniferous Basin) and the East European Craton

Temporal record of osmium concentrations and 187Os/188Os in organic-rich mudrocks: Implications for the osmium geochemical cycle and the use of osmium as a paleoceanographic tracer

The final publication is available at Elsevier via https://doi.org/10.1016/j.gca.2017.06.046 © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/We present a compilation of 192Os concentrations (representing non-radiogenic Os) and initial 187Os/188Os isotope ratios from organic-rich mudrocks (ORM) to explore the evolution of the Os geochemical cycle during the past three billion years. The initial 187Os/188Os isotope ratio of a Re-Os isochron regression for ORM constrains the local paleo-seawater 187Os/188Os, which is governed by the relative magnitudes of radiogenic Os (old continental crust) and unradiogenic Os (mantle, extraterrestrial, and juvenile/mafic/ultramafic crust) fluxes to seawater. A first-order increase in seawater 187Os/188Os ratios occurs from the Archean to the Phanerozoic, and may reflect a combination of increasing atmosphere-ocean oxygenation and weathering of progressively more radiogenic continental crust due to in-growth of 187Os from radioactive decay of 187Re. Superimposed on this long-term trend are shorter-term fluctuations in seawater 187Os/188Os ratios as a result of climate change, emplacement of large igneous provinces, bolide impacts, tectonic events, changes in seafloor spreading rates, and lithological changes in crustal terranes proximal to sites of ORM deposition. Ediacaran-Phanerozoic ORM have mildly higher 192Os concentrations overall compared with pre-Ediacaran Proterozoic ORM based on the mean and 95% confidence interval of 10,000 median values derived using a bootstrap analysis for each time bin (insufficient Archean data exist for robust statistical comparisons). However, there are two groups with anomalously high 192Os concentrations that are distinguished by their initial 187Os/188Os isotope ratios. Ediacaran-Cambrian ORM from South China have radiogenic initial 187Os/188Os, suggesting their high 192Os concentrations reflect proximal Os-rich crustal source(s), ultraslow sedimentation rates, and/or other unusual depositional conditions. In contrast, the unradiogenic initial 187Os/188Os and high 192Os concentrations of some Mesozoic ORM can be tied to emplacement of large igneous provinces. Excluding these two anomalous groups and repeating the bootstrap analysis, we find that, overall, the 192Os concentrations for the Ediacaran-Phanerozoic and pre-Ediacaran Proterozoic time bins are not significantly different. An improved understanding of Os geochemical behavior in modern environments is required before our compilation can be fully used to constrain the temporal evolution of the seawater Os reservoir.NSERC Discovery Grant || (RGPIN-435930

4-(3-Methoxy­phen­yl)-2,6-dimethyl­cyclo­hex-3-enecarboxylic acid

The racemic title compound, C16H20O3, was synthesized to study the hydrogen-bonding inter­action of the two enanti­o­mers in the solid state. In the crystal structure, R and S pairs of the racemate are linked by pairs of inter­molecular O—H⋯O hydrogen bonds, producing centrosymmetric R 2 2(8) rings

Uruk Colonies and Anatolian Communities: An Interim Report on the 1992-1993 Excavations at Hacinebi, Turkey

The first Mesopotamian city-states in the Uruk period (ca. 3800-3100 B. C.) pursued a strategy of commercial expansion into neighboring areas of the Zagros Mountains, Syria, and southeastern Anatolia. Recent research in these areas has located several Uruk outposts, in what is apparently the world\u27s earliest-known colonial system. Although some Uruk colonies have been excavated, virtually nothing is known about either the operation of this system or its role in the development of local polities in Anatolia. Excavations at the site of Hacinebi, on the Euphrates River trade route, investigate the effects of the Uruk Expansion on the social, economic, and political organization of southeastern Anatolia during the fourth millennium B. C. Hacinebi has two main Late Chalcolithic occupations - a pre-contact phase A and a later contact phase B with high concentrations of Uruk ceramics, administrative artifacts, and other Mesopotamian forms of material culture. The Hacinebi excavations thus provide a rare opportunity to investigate the relationship between the Uruk colonies and the local populations with whom they traded, while clarifying the role of long-distance exchange in the development of complex societies in Anatolia. Several lines of evidence suggest that the period of contact with Mesopotamia began in the Middle Uruk period, earlier than the larger colonies at sites such as Habuba Kabira-South and Jebel Aruda in Syria. The concentrations of Uruk material culture and the patterns of food consumption in the northeastern corner of the Local Late Chalcolithic settlement are consistent with the interpretation that a small group of Mesopotamian colonists lived as a socially distinct enclave among the local inhabitants of Hacinebi. There is no evidence for either Uruk colonial domination or warfare between the colonists and the native inhabitants of Hacinebi. Instead, the presence of both Anatolian and Mesopotamian seal impressions at the site best fits a pattern of peaceful exchange between the two groups. The evidence for an essential parity in long-term social and economic relations between the Mesopotamian merchants and local inhabitants of Hacinebi suggests that the organization of prehistoric Mesopotamian colonies differed markedly from that of the better-known 16th-20th century European colonial systems in Africa, Asia, and the Americas

Re-Os and U-Pb Geochronology of the Doña Amanda and Cerro Kiosko Deposits, Bayaguana District, Dominican Republic: Looking Down for the Porphyry Cu-Mo Roots of the Pueblo Viejo-Type Mineralization in the Island-Arc Tholeiitic Series of the Caribbean

Hosted in the Early Cretaceous bimodal tholeiite volcanic series of the Los Ranchos Formation, the Doña Amanda and Cerro Kiosko deposits in the Bayaguana district represent significant Au, Cu, and Ag resources in the Cordillera Oriental of the Dominican Republic. At Doña Amanda, a dense stockwork of quartz-sulfide veins is hosted by volcanic rocks with intense transitional phyllic-advanced argillic and silicic hydrothermal alteration assemblages, indicating a high-sulfidation environment. Wavy quartz veins with central sutures and rims of pyrite + enargite + molybdenite + fahlore (B veins) are cut by planar quartz-pyrite D veins. Primary fluid inclusions in quartz from B veins (Th: 160°->400°C; salinity: 7.9-16.4 wt % NaCl equiv) are interpreted as porphyry-type fluids. Inclusion fluids in quartz of quartz-pyrite veins (Th: 125°-175°C; salinity: 4.8-12.2 wt % NaCl equiv), quartz from silicic altered wall rocks (Th: 150°-175°C; salinity: 8.3-13.9 wt % NaCl equiv), and late, distal calcite veins (Th: 120°-160°C; salinity: 5.0-13.3 wt % NaCl equiv) indicate limited mixing with more dilute fluids and rule out mixing with fresh meteoric water. In Cerro Kiosko, a swarm of fault-controlled massive chalcopyrite + enargite + bornite + fahlore D veins and lodes are hosted by rocks with pervasive kaolinite alteration after sericite. δ34S values of vein sulfides from both deposits are all close to −2¿ and consistent with a predominance of magmatic sulfur and sulfide deposition from an oxidizing magmatic fluid. These data are consistent with a transitional environment between a deeper porphyry Cu(-Mo) and an overlying high-sulfidation epithermal deposit. An Re-Os age (112.6 ± 0.4 Ma) for molybdenite from the Doña Amanda deposit places the porphyry-epithermal mineralization as Early Cretaceous, coeval with the Los Ranchos Formation host rocks and with the Pueblo Viejo deposit. New sensitive high-resolution ion microprobe U-Pb ages on zircons from plagioclase-phyric rhyolite domes in the Bayaguana district are consistent with porphyry-high-sulfidation epithermal mineralization occurring along the Los Ranchos Formation during tonalite batholith emplacement in the basaltic island-arc basement at ca. 118 to 112 Ma and finalization of felsic volcanism at ca. 110 to 107 Ma

Marine redox conditions during deposition of Late Ordovician and Early Silurian organic-rich mudrocks in the Siljan ring district, central Sweden

The final publication is available at Elsevier via https://doi.org/10.1016/j.chemgeo.2017.03.015 © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 licenseThe Late Ordovician Period witnessed the second largest mass extinction in the Phanerozoic Eon and the Hirnantian glaciation. To infer ocean redox conditions across the Ordovician-Silurian transition, we measured the U (as δ238U relative to standard CRM145 = 0‰) and Mo (as δ98Mo relative to standard NIST SRM 3134 = +0.25‰) isotope compositions of 26 organic-rich mudrock samples from the Late Ordovician (Katian) Fjäcka Shale and the Early Silurian (Aeronian-Telychian) Kallholn Formation (Siljan ring district, Sweden). The magnitude of Re,Mo, and U enrichments, ReEF/MoEF and UEF/MoEF ratios, and sedimentary Fe speciation point to locally euxinic bottom water conditions during deposition of the Fjäcka Shale. The same proxies suggest that black shales of the Kallholn Formation were deposited under transiently euxinic conditions with the chemocline situated near the sediment-water interface, whereas gray shales stratigraphically equivalent to the upper Kallholn Formation were deposited from oxygenated bottom waters. These observations are consistent with higher δ98Mo and δ238U in the Fjäcka Shale compared with the Kallholn Formation. Because the Fjäcka Shalewas deposited from persistently euxinic bottomwaters, theMo and U isotope compositions from these rocks can be used to estimate the extent of global ocean euxinia and ocean anoxia (euxinic plus ferruginous conditions), respectively. Elevated MoEF and Mo/TOC ratios in the euxinic Fjäcka Shale suggest no more than moderate basin restriction from the open ocean as well as non-quantitative removal ofMo from the euxinic bottom waters, thus pointing toMo isotope fractionation between seawater and the euxinic sediments. Hence, we infer that even the highest δ98Mo(+1.28‰) preserved in the Fjäcka Shale is only aminimum estimate for theMoisotope composition of coeval global seawater. Correcting for seawater-sediment Mo isotope fractionation, the δ98Mo of late Katian seawater may have been +1.4–2.1‰, which corresponds to ~10–70% Mo removal into the euxinic sink. The average authigenic δ238U of the Fjäcka Shale is −0.05‰ to +0.02‰ after correcting for a range of possible detrital δ238U values, thus yielding an overall average of ~0‰. Taking into account isotope fractionation during U removal to euxinic sediments, we infer that late Katian seawater δ238U was about−0.85‰to−0.60‰. A steady-state U isotope mass balance model reveals that 46–63% of riverine U input was removed in anoxic settings. Based on the Mo and U isotope data, we infer that euxinic and anoxic waters may have covered b1% and at least 5% (potentially tens of percent) of the total seafloor area during the late Katian, respectively, based on previously publishedmodels that relate themagnitude of Mo and U burial fluxes to the areal extent of euxinic and anoxic seafloor. By comparison, only 0.21–0.35% and b1% of the total seafloor area was covered by anoxic waters today and during the Cenozoic, respectively. The difference between the estimated extent of ocean anoxia (euxinic plus ferruginous) and ocean euxinia points to an appreciable extent of ferruginous water masses during the late Katian. Integration of our data with previous studies thus supports the hypothesis that ocean oxygenation intensified during the subsequent Hirnantian glaciation (when seawater δ98Motemporarily reached values similar to today). Hence, environmental stresses related to glaciation, not an expansion of ocean anoxia,may have triggered the first phase of the Hirnantianmass extinction.NSERC Discovery grant || (RGPIN-435930) Chinese 973 program || (grant No. 2013CB955704) NSFC || (grant No. 41172030

Drug treatment program patients' hepatitis C virus (HCV) education needs and their use of available HCV education services

BACKGROUND: In spite of the disproportionate prevalence of hepatitis C virus (HCV) infection among drug users, many remain uninformed or misinformed about the virus. Drug treatment programs are important sites of opportunity for providing HCV education to their patients, and many programs do, in fact, offer this education in a variety of formats. Little is known, however, about the level of HCV knowledge among drug treatment program patients, and the extent to which they utilize their programs' HCV education services. METHODS: Using data collected from patients (N = 280) in 14 U.S. drug treatment programs, we compared patients who reported that they never injected drugs (NIDUs) with past or current drug injectors (IDUs) concerning their knowledge about HCV, whether they used HCV education opportunities at their programs, and the facilitators and barriers to doing so. All of the programs were participating in a research project that was developing, implementing, and evaluating a staff training to provide HCV support to patients. RESULTS: Although IDUs scored higher on an HCV knowledge assessment than NIDUs, there were many gaps in HCV knowledge among both groups of patients. To address these knowledge gaps, all of the programs offered at least one form of HCV education: all offered 1:1 sessions with staff, 12 of the programs offered HCV education in a group format, and 11 of the programs offered this education through pamphlets/books. Only 60% of all of the participating patients used any of their programs' HCV education services, but those who did avail themselves of these HCV education opportunities generally assessed them positively. In all, many patients were unaware that HCV education was offered at their programs through individual sessions with staff, group meetings, and books/pamphlets, (42%, 49%, and 46% of the patients, respectively), and 22% were unaware that any HCV education opportunities existed. CONCLUSION: Efforts especially need to focus on ensuring that all drug treatment program patients are made aware of and encouraged to use HCV education services at their programs

Reviews and syntheses:Remotely sensed optical time series for monitoring vegetation productivity

International audienceAbstract. Vegetation productivity is a critical indicator of global ecosystem health and is impacted by human activities and climate change. A wide range of optical sensing platforms, from ground-based to airborne and satellite, provide spatially continuous information on terrestrial vegetation status and functioning. As optical Earth observation (EO) data are usually routinely acquired, vegetation can be monitored repeatedly over time; reflecting seasonal vegetation patterns and trends in vegetation productivity metrics. Such metrics include e.g., gross primary productivity, net primary productivity, biomass or yield. To summarize current knowledge, in this paper, we systematically reviewed time series (TS) literature for assessing state-of-the-art vegetation productivity monitoring approaches for different ecosystems based on optical remote sensing (RS) data. As the integration of solar-induced fluorescence (SIF) data in vegetation productivity processing chains has emerged as a promising source, we also include this relatively recent sensor modality. We define three methodological categories to derive productivity metrics from remotely sensed TS of vegetation indices or quantitative traits: (i) trend analysis and anomaly detection, (ii) land surface phenology, and (iii) integration and assimilation of TS-derived metrics into statistical and process-based dynamic vegetation models (DVM). Although the majority of used TS data streams originate from data acquired from satellite platforms, TS data from aircraft and unoccupied aerial vehicles have found their way into productivity monitoring studies. To facilitate processing, we provide a list of common toolboxes for inferring productivity metrics and information from TS data. We further discuss validation strategies of the RS-data derived productivity metrics: (1) using in situ measured data, such as yield, (2) sensor networks of distinct sensors, including spectroradiometers, flux towers, or phenological cameras, and (3) inter-comparison of different productivity products or modelled estimates. Finally, we address current challenges and propose a conceptual framework for productivity metrics derivation, including fully-integrated DVMs and radiative transfer models here labelled as "Digital Twin". This novel framework meets the requirements of multiple ecosystems and enables both an improved understanding of vegetation temporal dynamics in response to climate and environmental drivers and also enhances the accuracy of vegetation productivity monitoring