Combustion metamorphism in southern california

In several places in Southern California bituminous sediments of the Monterey Formation-siliceous shales, phosphatic rocks, dolomites, and arkoses-were affected during the Pleistocene and as late as the l9th century by spontaneous subsurface combustion of organic matter, during which temperatures up to 1600 degrees C were reached. This oxidative heating (combustion metamorphism) affected rock complexes over areas of tens of square kilometers that tend to occur in clusters. As a result of these processes, the rocks recrystallized and partially melted to form pseudomagmas which intruded the country rocks. The chemical compositions of these melts differ from those of igneous magmas. Acid and intermediate siliceous melts as well as phosphatic melts have formed. These two types are generally immiscible. The following high-temperature minerals were determined: alpha- and beta-cristobalite, quartz, calcic plagioclase, diopsidic pyroxene, wollastonite, cordierite, graphite, fluorapatite, and fluorite; at lower temperature pyrite, gypsum, aragonite, calcite, jarosite, and hexahydrite crystallized.     

The pulvinar regulates information transmission between cortical areas based on attention demands

Selective attention mechanisms route behaviorally relevant information through large-scale cortical networks. Although evidence suggests that populations of cortical neurons synchronize their activity to preferentially transmit information about attentional priorities, it is unclear how cortical synchrony across a network is accomplished. Based on its anatomical connectivity with the cortex, we hypothesized that the pulvinar, a thalamic nucleus, regulates cortical synchrony. We mapped pulvino-cortical networks within the visual system, using diffusion tensor imaging, and simultaneously recorded spikes and field potentials from these interconnected network sites in monkeys performing a visuospatial attention task. The pulvinar synchronized activity between interconnected cortical areas according to attentional allocation, suggesting a critical role for the thalamus not only in attentional selection but more generally in regulating information transmission across the visual cortex.     

Advances and challenges in marine conservation in Chile: A regional and global comparison

1. Despite significant progress made in Chile, and globally, in establishing marine protected areas (MPAs), the actual contribution to marine biodiversity conservation needs to be revised, to focus on representativeness and the diversity of tools alongside effective implementation, management, and enforcement.
2. This study makes progress in this direction, describing the most recent advances in marine conservation in Chile and analysing the contribution of the different conservation instruments as well as the distribution of designated areas across ecoregions. Furthermore, it examines the potential contribution of alternative area-based instruments to balance ocean protection. The advances observed in Chile were compared among four South American countries and five leading countries in ocean conservation, analysing protection levels in coastal areas, continental exclusive economic zones, and overseas territories.
3. Data on MPA boundaries and attributes were sourced from the World Database on Protected Areas and complemented the official information on MPAs and territorial user rights for fisheries and for indigenous people in South America.
4. The current level of protection in Chile is among the highest in the world in area coverage and in the proportion of the continental exclusive economic zone assigned to fully protected areas. However, it exhibits the strongest imbalances in the distribution of designated MPAs between coastal and oceanic waters, in comparison with the leading countries and also within South America (Perú, Chile, Argentina, and Uruguay), and among ecoregions.
5. The patterns observed suggest that Chile has advanced, but concentrated, conservation efforts in low-threat, remote ecoregions. There is an urgent need to progress towards high-threat ecoregions, which implies balancing the needs of nature and people. The distribution of ancillary conservation instruments can help double the level of protection in threatened coastal areas, filling gaps in marine conservation and creating an opportunity to progress and diversify conservation strategies.

     

Copper artifacts: correlation with source types of copper ores

Six out of eight minor chemical elements, determined by spectroscopic and neutron-activation techniques, were found to be critical in computing a probability that a given copper artifact was derived from one of three types of copper ore: native metal, oxidized ore, reduced ore. Two elements, gold and tin, were apparently alloyed deliberately in many artifacts from both the Old World and the New World.     

Environmental Factors Controlling Soil Organic Carbon Stocks in Two Contrasting Mediterranean Climatic Areas of Southern Spain

Managing soil carbon requires accurate estimates of soil organic carbon (SOC) stocks and its dynamics, at scales able to capture the influence of local factors on the carbon pool. This paper develops a spatially explicit methodology to quantify SOC stocks in two contrasting regions of Southern Spain: Sierra Norte de Sevilla (SN) and Cabo de Gata (CG). Also, it examines the relationship between SOC stocks and local environmental factors. Results showed that mean SOC stocks were 4·3 kg m⁻² in SN and 3·0 kg m⁻² in CG. Differences in SOC in both sites were not significant, suggesting that factors other than climate have a greater influence on SOC stocks. A correlation matrix revealed that SOC has the highest positive correlation with clay content and soil depth. Based on the land use, the largest SOC stocks were found in grassland soils (4·4 kg m⁻² in CG and 5·0 kg m⁻² in SN) and extensive crops (3·0 kg m⁻² in CG and 5·0 kg m⁻² in SN), and the smallest under shrubs (2·8 kg m⁻² in CG and 3·2 kg m⁻² in SN) and forests soils (4·2 kg m⁻² in SN). This SOC distribution is explained by the greatest soil depth under agricultural land uses, a common situation across the Mediterranean, where the deepest soils have been cultivated and natural vegetation mostly remains along the marginal sites. Accordingly, strategies to manage SOC stocks in southern Spain will have to acknowledge its high pedodiversity and long history of land use, refusing the adoption of standard global strategies. Copyright © 2015 John Wiley & Sons, Ltd.     

Controlled laboratory system to study soil solarization and organic amendment effects on plant pathogens

ABSTRACT A controlled laboratory system for simulating soil solarization, with and without organic amendment, was developed and validated using physical, chemical, and biological parameters. The system consists of soil containers that are exposed to controlled and constant aeration, and to temperature fluctuations that resemble those occurring during solarization at various depths. This system enables a separate analysis of volatiles and other components. We recorded a sharp decrease in oxygen concentration in the soil atmosphere followed by a gradual increase to the original concentration during solarization in the field and heating in the simulation system of soil amended with wild rocket (Diplotaxis tenuifolia) or thyme (Thymus vulgaris). The combined treatment of organic amendment and solarization (or heating in the controlled system) was highly effective at controlling populations of Fusarium oxysporum f. sp. radicis-lycopersici. Changes in soil pH, enzymatic activities, and microbial populations followed, in most cases, trends which were similar under both solarization and the heating system, when exposed to controlled aerobic conditions. The reliability and validity of the system in simulating physical, chemical, and biological processes taking place during solarization is demonstrated.     

Untersuchungen zur Akarizidresistenz an Populationen der Obstbaumspinnmilbe, Panonychus ulmi KOCH (Acari: Tetranychidae) aus dem Bodenseegebiet

One of the major acarine pest species of deciduous fruit trees like apple and plum is the European red mite, Panonychus ulmi KOCH (Acari: Tetranychidae). Feeding damage by P. ulmi results in leaf bronzing followed by an early defoliation and a reduction in yield, which is usually prevented by the application of acaricides. A problem often associated with mite control is the (sometimes rapid) development of resistance due to their high reproductive potential, a short life cycle allowing numerous generations per season and frequent applications of acaricides. Therefore a resistance monitoring is considered to be an essential part within resistance management strategies where only compounds providing full efficacy at recommended rates should be used. Once a new acaricide is considered for market introduction a so-called baseline susceptibility study is requested by the European authorities. Such a baseline study was also conducted for the new acaricidal compound spirodiclofen (Envidor^®), which is known to inhibit lipid biosynthesis and particularly active against juvenile stages of tetranychid mite pests such as P. ulmi. However, a strong reduction of female adult fecundity results in excellent residual efficacy. Here we report on the baseline susceptibility of 15 European red mite populations against spirodiclofen, which were collected in 2005 in apple orchards at Lake Constance, Germany. The baseline data were combined because of a low population-to-population variation in response to spirodiclofen and a composite dose effect calculation revealed a diagnostic concentration (LC₉₅) of 5?mg/liter (ppm) for future monitoring purposes in P. ulmi larvae. Furthermore we checked the susceptibility of the very same field populations against pyridaben, hexythiazox and abamectin. This helps to identify candidates for a balanced resistance management strategy avoiding the implication of cross-resistance issues.     

COMPARISON BETWEEN SURVEY RADIOGRAPHY,B‐MODE ULTRASONOGRAPHY,CONTRAST‐ENHANCED ULTRASONOGRAPHY AND CONTRAST‐ENHANCED MULTI‐DETECTOR COMPUTED TOMOGRAPHY FINDINGS IN DOGS WITH ACUTE ABDOMINAL SIGNS

Contrast‐enhanced multi‐detector computed tomography (CE‐MDCT) is used routinely in evaluating human patients with acute abdominal symptoms. Contrast‐enhanced ultrasound (CEUS) continues to be in its infancy as it relates to evaluation of the acute abdomen. The purpose of this study was to compare survey radiography, B‐mode ultrasound, CEUS, and CE‐MDCT findings in canine patients presenting with acute abdominal signs; with a focus on the ability to differentiate surgical from non‐surgical conditions. Nineteen dogs were prospectively enrolled. Inclusion required a clinical diagnosis of acute abdominal signs and confirmed surgical or non‐surgical causes for the clinical signs. Agreement for the majority of recorded imaging features was at least moderate. There was poor agreement in the identification of pneumoperitoneum and in the comparison of pancreatic lesion dimensions for B‐mode vs. CEUS. The CT feature of fat stranding was detected in cases including, but not limited to, gastric neoplasia with perforation, pancreatitis, and small intestinal foreign body. Ultrasound underestimated the size and number of specific lesions when compared with CE‐MDCT. Contrast‐enhanced ultrasound was successful in detecting bowel and pancreatic perfusion deficits that CE‐MDCT failed to identify. Accuracy for differentiation of surgical vs. non‐surgical conditions was high for all modalities; 100%, 94%, and 94% for CE‐MDCT, ultrasonography and survey radiography respectively. Findings indicated that CE‐MDCT is an accurate screening test for differentiating surgical from non‐surgical acute abdominal conditions in dogs. Focused CEUS following CE‐MDCT or B‐mode ultrasonography may be beneficial for identifying potentially significant hypoperfused lesions.