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•Combination of geostatistical and hierarchical clustering methods was effective.•Hydrothermally mineralized and altered zones with Au enrichment were delineated.•Vein system and ...mineralized zones of an Au-rich epithermal deposit were revealed.•Possible fluid pathways along fractures in deep zones were also detected.•The methods model location, continuity, and formation process of high-grade zones.
Even though epithermal vein-type deposits are the main sources of Au and Ag worldwide, accurate three-dimensional modeling of vein structures and the extraction of high-grade zones are still difficult because of geologic structure heterogeneities and the scarcity of available data, mostly obtained via drilling. Accordingly, by selecting a low-sulfidation epithermal Au–Ag deposit in the Philippine archipelago, we develop an efficient and reliable workflow for determining the spatial distribution of Au-rich veins in detail and the transport of hydrothermal fluids. The studied deposit is mostly hosted in open fractures and breccias with a relatively large tonnage of low Au+Ag grades and/or a small tonnage of high Au+Ag grades. The whole-rock geochemical data (1877 core samples) and lithological data (56 drilling sites) are processed using hierarchical clustering analysis (HCA) and two geostatistical simulations: turning bands simulation for the Au grade distribution and interpretation of mineralization process and truncated Gaussian simulation for the spatial distribution of clusters with similar Au–Ag grade features as classified by HCA. The general correlation between the Au and Ag grades, with a linear correlation coefficient of ≈ 0.69, is based on the HCA application, and the clusters were likely formed by three-stage mineralization processes. A plausible three-dimensional geologic model is then constructed, delineating in detail hydrothermally mineralized and altered zones with Au enrichment and vein system structures in the study area.
Canine leishmaniosis is a potentially life-threatening disease which is spreading geographically in the Old and New Worlds, where different diagnostic procedures, treatments, and control strategies ...are currently in place. This Opinion article outlines the similarities and differences between canine leishmaniosis in the Old and New Worlds, with emphasis on South America and Europe. Finally, it calls the attention of veterinary and public health authorities to standardize and improve practices for diagnosing, treating, and preventing the disease.
In 2023 Amazonia experienced both historical drought and warm conditions. On October 26th 2023 the water levels at the port of Manaus reached its lowest record since 1902 (12.70 m). In this region, ...October monthly maximum and minimum temperature anomalies also surpassed previous record values registered in 2015 (+ 3 °C above the normal considering the 1981-2020 average). Here we show that this historical dry and warm situation in Amazonia is associated with two main atmospheric mechanisms: (i) the November 2022-February 2023 southern anomaly of vertical integrated moisture flux (VIMF), related to VIMF divergence and extreme rainfall deficit over southwestern Amazonia, and (ii) the June-August 2023 downward motion over northern Amazonia related to extreme rainfall deficit and warm conditions over this region. Anomalies of both atmospheric mechanisms reached record values during this event. The first mechanism is significantly correlated to negative sea surface temperature (SST) anomalies in the equatorial Pacific (November-February La Niña events). The second mechanism is significantly correlated to positive SST anomalies in the equatorial Pacific, related to the impacts of June-September El Niño on the Walker Circulation. While previous extreme droughts were linked to El Niño (warmer North Tropical Atlantic SST) during the austral summer (winter and spring), the transition from La Niña 2022-23 to El Niño 2023 appears to be a key climatic driver in this record-breaking dry and warm situation, combined to a widespread anomalous warming over the worldwide ocean.
An incumbent and an other licensed operator may jointly invest to develop fiber network infrastructure while an outsider operator invests to develop cable network infrastructure. Regardless whether ...the investment sharing agreement occurs, market exclusion of the facility-based outsider does not hold. Considering the prevalence of the investment sharing agreement, it is not necessarily true that each insider contributes with an investment share of 50% since there may exist a trade-off between bargaining power and investment participation. Although full integration avoids duplication of investment costs, social welfare may be higher under partial integration. Presuming the increasing run for fiber, the framework proposes the inclusion of a fourth service-based operator that requires access to the fiber network infrastructure held by the consortium. This may define a tight oligopoly with simultaneous presence of investment sharing agreement. The service-based outsider is excluded from the retail market when the wholesale access price is unregulated. Subsequently, market exclusion depends on the competitive nature of the outsider firm. Finally, the framework reveals the conditions that legitimize ex-post regulation of the wholesale access price of fiber. An asymmetric regulatory intervention at the wholesale access price level is justified as a means of improving social welfare if the investment effort is excessively high. The same applies if the investment effort is intermediate, provided that an excessively high gap exists between the vertical spillover that affects the fiber consortium in relation to the vertical spillover that affects the cable operator.
•Exclusion with investment sharing depends on the competitive nature of outsiders.•There exists a trade-off between bargaining power and investment participation.•Full integration may not improve social welfare relative to partial integration.•Ex-post regulation of the wholesale access price may improve social welfare.
In recent decades, significant global attention has been devoted to mitigating the negative consequences of air pollution and vehicular emissions on public health and climate change. One technology ...that has shown promise in reducing particulate engine emissions is supercritical combustion. This study introduces a reduced kinetic model (155 species and 1106 reactions) for oxidation analysis of supercritical ethanol/gasoline blends. A combination of reducing techniques (sensitivity Analysis and the directed relation graph error propagation) and a combination process (reaction packages method) were used to develop a new reduced ethanol/gasoline surrogate mechanism. The validity of the reduced combined mechanism was assessed using 0D constant-volume auto-ignition delay times (IDT) and 1D laminar flame speed simulations against experimental results. A modified cubic Redlich–Kwong equation of state was used to classify the state of each literature mixture tested in this work as supercritical or sub-critical, which can cooperate and endorse the supercritical combustion processes into engines. The proposed gasoline/ethanol mechanism provides consistent IDT results concerning the experimental shock tube data under high pressure for gasoline surrogate/ethanol/air blends at 30–55 atm and for pure ethanol/air at 20, 30, and 75 atm. The gasoline surrogate IDT results agreed well at the temperature range of 720 K up to 1250 K. Although the ethanol IDT results had an excellent agreement for the high-pressure (75 atm) and intermediate and high-temperature conditions (
≥
850 K), it has a slightly lower agreement at 20 and 30 atm and temperatures lower than 800 K.
Endemic in Brazil, visceral leishmaniasis (VL) is a zoonotic infection that is among the most important parasitic diseases transmitted by vectors. Dogs are the main reservoirs of canine leishmaniasis ...(CanL) and their identification is used in some countries as part of disease prevention and control measures in the canine and human population. In this context, serological tests are necessary, composed of antigens capable of correctly identifying infected dogs, minimizing the number of false-negative cases. This study aimed to identify more immunoreactive peptides derived from two previously described whole proteins (rDyn-1 and rKDDR-plus) and compare their performance to the control antigens rK39 and the crude extract for the detection of dogs infected with L. infantum, especially the asymptomatic ones. The three selected peptides and a mixture of them, along with the rDyn-1, rKDDR-plus, rK39, and crude extract antigens were evaluated using indirect ELISA with sera samples from 186 dogs with CanL, being asymptomatic (n = 50), symptomatic (n = 50), co-infected (n = 19), infected with Babesia sp. (n = 7), Ehrlichia sp. (n = 6), T. cruzi (n = 20) and uninfected (n = 34). The results showed that the rDyn-1 protein and the peptide mixture had the highest sensitivity (100% and 98.32%, respectively) and specificity (97.01 and 98.51, respectively). A high degree of kappa agreement was found for rDyn-1 protein (0.977), mixed peptides (0.965), rKDDR-plus protein (0.953), K-plus peptide 1 (0.930) and Dyn-1 peptide (0.893). The mixture of peptides showed the highest likelihood (65.87). The ELISA using the mixture of peptides and the rDyn-1 protein showed high performance for CanL serodiagnosis. More mix combinations of the peptides and additional extended field tests with a larger sample size are recommended.
Three-dimensional modeling of geoscientific data of limited amounts and strongly biased locations is difficult and impractical using almost any method. To obtain a correct spatial model from data ...under such constraints, this study systematically demonstrated the effectiveness of neural kriging (NK), which is based on a deep neural network (DNN) with a semivariogram learning criterion. As a novel case study of resource geology, NK was applied to clarify the three-dimensional deposit structure of an active seafloor hydrothermal vent area, Izena Hole in the middle Okinawa Trough, using Cu, Zn, Pb, Ag, and Ba content data, geological columns, and resistivity data from drill core samples obtained at six drill sites aligned nearly E–W and two drill sites far from these six. Two high-content zones clearly appeared for all five elements, in the sulfide mound and underlying sediment, and about 30 m below the seafloor as a stratiform shape. Advantages of NK were demonstrated as follows. The NK results showed the locations of these high-content zones and their horizontal extent along the pathway of hydrothermal fluids more clearly than the result of typical geostatistical simulation, turning bands simulation (TBS), by enabling content estimations even in areas without data. NK also estimated the uppermost high-content zones more accurately than the ordinal DNN methods or TBS. Next, NK was tested for a region 20 times wider than the first target, and the resultant Cu and Zn content models showed indistinct horizontal linear features and vertical continuity, which may have been caused by the fault structure and small amounts of metal precipitation in the deep part, respectively. Thus, one advantage of NK is that its spatial model can contribute to constructing hypotheses of transport and enrichment mechanisms of target metals.
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•An active hydrothermal system was modeled over 500 by 200 m area to 170 m depth.•Combination of geostatistical and data-characterization methods was effective.•Modeling was ...implemented through sparse drill site data at only six locations.•Configuration and zonation of subseafloor metal deposits were revealed.•New models of hydrothermal flow and metal accumulation were proposed.
Seafloor hydrothermal deposits in the Okinawa Trough have been regarded as a modern analog of kuroko-type volcanogenic massive sulfide (VMS) deposits on land. VMS deposit is one of the primary producers of base metals (e.g. Cu, Pb, Zn) and precious metals (e.g. Au, Ag). However, owing to difficulties in accessing subseafloor samples/data without costly drilling operations, the spatial distribution of metal contents below the seafloor remains poorly constrained. We apply a combination of four spatial modeling methods: (1) principal component analysis; (2) k-means clustering; and (3, 4) conditional geostatistical simulations of turning bands and pluri-Gaussian. These modeling methods are based on the whole-rock geochemical data using inductively coupled plasma-quadruple mass spectrometry, together with lithologic log data obtained from onboard visual core descriptions, and X-ray diffraction analyses from the middle Okinawa Trough, Izena Hole, during the cruise CK16-05 (Expedition 909) in 2016 by D/V Chikyu. The primary goal is to construct plausible 3D models for the contents of base metals and silver as well as lithotypes. The constructed models successfully map the configuration and zonation of subseafloor metal deposits with hydrothermal flow paths, which sheds light on hydrothermal circulation systems and metal accumulation mechanisms. This approach is shown to be effective for geologic and mineralization modeling and exploration of (sub)seafloor hydrothermal deposits.
Certain guidelines recommend a second-generation H1-antihistamine (AH) as first-line treatment for patients with chronic urticaria (CU). However, some patients show insufficient response to a ...standard dose of this therapy and might benefit from adding leukotriene receptor antagonists (LTA). Therefore, we aimed to perform a systematic review and meta-analysis comparing LTA plus antihistamines with antihistamines alone. We performed a systematic review and meta-analysis, searching PubMed, EMBASE, and Cochrane Central for randomized clinical trial (RCT) data comparing LTA plus AH treatment to AH alone in patients with CU. Statistical analysis was performed using R Studio 4.3.2. Heterogeneity was assessed with I
statistics. Three studies comprising 234 patients with urticaria were included. The mean age was 37.23 years in the leukotriene antagonist + antihistamines (LTA + AH) group and 39.14 years in the antihistamines (AH) group. Follow-up ranged from 2 to 18 months between studies. There was no statistically significant difference between groups in terms of TSS level (SMD: -74.82; 95% CI: -222.66 to 73.02; P = 0.32; I
= 98%), neither in terms of pruritus (MD: -0.07; 95% CI: -0.42 to 0.28; P = 0.70; I
= 74%). After sensitivity analysis, with the systematic exclusion of each study from the grouped estimates, the result for TSS level did not change. These findings suggest that leukotriene receptor antagonists with antihistamines do not have better outcomes than antihistamines alone regarding TSS and pruritus in patients with CU.
