Main Provinces Research Articles

Comparison of petrological and geochemical characteristics of three different types of Eocene copper-gold mineralization in eastern Iran

The Maherabad, Qaleh Zari, and Hired deposits in eastern Iran are porphyry (Cu-Au)-, Iron oxide copper–gold (IOCG)-, and reduced intrusion-related gold system (RIRGS)-type mineralization, respectively. They are located within the Lut block magmatic assemblage, which is the main metallogenic province in eastern Iran. The mineral assemblages and paragenesis of the deposits indicate that highest log fO2 and log fS2 contents belong to the Qaleh Zari deposit. In contrast, the lowest values of oxygen and sulphur fugacity are related to the RIRGS system in the Hired deposit. The Maherabad mineralization has moderate log fO2 and log fS2 contents relative to the Qaleh Zari and Hired deposits.Geochemically, these three deposits are related to different types of granitoids, which occurred within the short time interval from 37 to 41 Ma. The Maherabad and Qaleh Zari intrusions are related to oxidized magnetite-series granitoids, whereas the mineralization at Hired deposit is related to the reduced ilmenite-series granitoids. Magnetite-series intrusive rocks at Hired are barren. Intrusive bodies in the three studied sites are metaluminous, high-K calc-alkaline to shoshonitic, and formed in a volcanic arc setting. However, there are distinct differences in the radiogenic isotopic composition, content of some elements and elemental ratios reflecting the effect of different sources in the formation of intrusions. The reduced granite of the Hired deposit has the lowest Eu/Eu* of <0.7, P + Sr < 1000 ppm, and Sr/Y < 20 associated with (La /Yb)N < 12. Crustal contamination played an important role in magma evolution (87Sr/86Sri = 0.70627 and −εNd(t) = -2.60). P + Sr and Sr/Y contents in the productive oxidant magnetite-series intrusive rocks, such as the Maherabad and Qaleh Zari deposits, are more than 1500 ppm and 35, respectively. On this basis, petrological characteristic, geochemical indicator elements and mineral assemblage and paragenesis can be used for discrimination of productive and barren intrusions in the three different deposit types studied in this research. This can be used as an exploration criteria for the hydrothermal deposits associated with different magmatic intrusions in some areas.

EXPLORATION PLAYS IN THE CAUCASUS REGION

Exploration efforts around the Greater Caucasus region started towards the end of the 19th century and established a wide range of petroleum play types in various basin segments around the orogen. All these plays are associated with the flanks of the inverted thrust‐fold belt and the adjacent foreland basin systems, but display significant variation among the basin segments depending on the tectonostratigraphic units involved and the degree of exploration maturity. Whereas the same main source rocks have generated most of the hydrocarbons in all the basins (namely organic‐rich shales in the Oligocene – Lower Miocene Maykop Group and the Eocene Kuma Formation), it is primarily the trapping style, both proven and speculative, which is responsible for the broad spectrum of play types observed. Eleven play type diagrams across six main petroleum provinces of the Greater Caucasus region are presented in this paper and summarize the current exploration understanding of the existing discoveries and potential new play targets. These play cartoons offer a prospect‐scale summary of both mature producing and underexplored basin segments in a coherent visual manner, and are therefore intended to promote future exploration efforts in the Caucasus region. The testing of new play types requires the proper risking of the two most critical elements in the region: hydrocarbon kitchen effectiveness, and post‐charge trap modification. The de‐risking of these factors will require properly designed, fit‐for‐purpose acquisition of modern geological and geophysical data sets.

Progress on inheritance and gene cloning for rice grain quality in Jiangsu province.

In China, rice (Oryza sativa L.) is a major cereal crop of great importance maintaining the food security and sustainable agricultural development. Jiangsu is one of the main provinces for rice production. After more than 40 years of development, the yield and quality of rice grain have made great progress. Rice grain quality is a complex trait involving production, processing, marketing and consumption of the grain. In this review, we summarize the progress on the genetic basis of main grain quality traits in the rice variety breeding in Jiangsu province and point out the achievement of each milestone. With a focus on the genetic regulation of grain appearance, eating and cooking quality and nutritional quality, we describe the classic genetic rules and molecular basis of rice grain quality traits and review the function of major genes that regulate corresponding traits. The genetics and improvement of grain quality achieved in Jiangsu province was highlighted on the domestic and international rice breeding programs. In particular, with the advance of breeding conception in terms of functional genomics and genetic regulatory networks, the specific molecular design for grain quality improvement will be the future direction of rice genetic breeding program of Jiangsu Province.

Life cycle greenhouse gas emissions of aluminum based on regional industrial transfer in China

AbstractAluminum production is a major energy consumer and source of greenhouse gas (GHG) emissions. The regional transfer of the primary aluminum (PA) industry, which mainly consists of the processes of electrolysis and aluminum ingot casting, is currently an important international trend in aluminum industrial development. However, the changes in GHG emissions from aluminum production for such transfers are unclear. This study has established a life cycle assessment model of aluminum industry based on regional transfers in the context of China, determined the GHG emissions of PA and secondary aluminum (SA) production, examined the GHG emission changes of PA production based on regional industry transfer between the years 2007 and 2017, and explored seven driving factors that affect GHG emissions in the aluminum industry. GHG emissions per unit PA and SA production in China decreased by 18.6% and 6.3%, respectively, but the total GHG emissions from aluminum industry still increased by 2.2 times between the years 2007 and 2017. The driving factor analysis showed that the major positive effects of GHG emissions from China's aluminum industry from 2007 to 2017 included the production scale effect of SA and the energy structure effect. Existing regional transfers (between the years 2007 and 2017) did not deliver significant annual GHG emissions reductions. Currently, Xinjiang, Henan, Shandong, and Inner Mongolia are the main PA production provinces in China, although regional transfers have been implemented. This study provides a basis for the improvement and sustainable development of the aluminum industry, suggests policies for regional aluminum development, and proposes a beneficial layout of the aluminum industry.

Complex System Analysis of Blumeria graminis f.sp. tritici Isolates Collected in Central Hebei Province, China

Wheat powdery mildew (WPM), caused by Blumeria graminis f.sp. tritici, is a significant disease of wheat throughout the world and has resulted in substantial yield and economic losses in wheat production. It is particularly important to understand the population distribution and genetic resistance of B. graminis f.sp. tritici. In 2019, the cumulative incidence of wheat powdery mildew in China was nearly 8.7 million hm2, which seriously affected the safe production of wheat in China. However, the proportion of disease-resistant wheat varieties in actual production was relatively low, and effective disease-resistant genes were lacking. As one of the main wheat-producing provinces in China, it is of great significance for normal wheat production to understand powdery mildew resistance in Hebei province. In this study, using wheat seedling culture in vitro, the physiological races of wheat powdery mildew in central Hebei province were identified, and the population toxicity frequency was analyzed. The results were as follows: (1) 36 strains were purified and 20 physiological races were identified. Among them, the dominant race is 015, and the distribution frequency is 16.7%. Race 077 is the second dominant race. (2) The frequency of virulence genes VEra, V8, V1, V3c, and V3f in population toxicity frequency analysis was more than 70%, while the frequency of virulence genes V2, MID, V20, V21, V4b, and V4 was less than 16.7%, and 46% of virulence genes of powdery mildew were higher than 40%. It shows that the virulence gene frequency of powdery mildew in Hebei province is high, and the varieties containing Pm2 + MID, Pm20, Pm21, Pm1b, Pm1, and other disease resistance genes have a certain value inbreeding.

Climatic Risk Assessment of Winter Wheat Aphids in Northern China

Northern China is a main winter wheat production area and plays an important role in ensuring food security. Wheat aphids, as one kind of main agricultural pest, threaten wheat production. Based on wheat aphids disaster and prevention data, planting area and yield loss of wheat, growth period of winter wheat, and daily meteorological data at 561 observation stations from 1958 to 2018 in 8 main wheat production provinces of northern China, relationships between surface meteorological factors and the occurrence area of wheat aphids for every province in North China and Huanghuai area are fully analyzed using methods of correlation analysis, principal component analysis and stepwise regression analysis in various time-periods from last December to 10 June. Eight key meteorological factors which affect the occurrence area of wheat aphids in North China and 6 key meteorological factors for Huanghuai area are determined. The climate disaster indices of wheat aphids are established based on the normalized key meteorological factors and validated in 8 provinces. Furthermore, climatic risk aspects are assessed to explore the occurrence tendency of winter wheat aphids in northern China. The frequencies of different-level decadal climate disasters are taken as hazard index, the ratio of occurrence area of wheat aphids to the wheat-sown area is defined as vulnerability index, and the ratio of controlled area to occurrence area is calculated to measure the disaster prevention and mitigation capability.Comprehensive risk index is built by integrating hazard, vulnerability, disaster prevention and mitigation capability indexes to assess risk development trend in decades. The results show that the climatic hazard for wheat aphids tends to increase gradually and there are significant differences in different decades. The vulnerability for wheat aphids tends to be severe over time.The disaster prevention and mitigation capability for wheat aphids tends to improve gradually especially in the 1990s, and the trend slows down since 2001. The comprehensive climatic risk has been more severe and their scopes of the highest risk have been larger since the 1990s. The climatic risk is highest in Beijing, Tianjin, central-south Hebei, part of north Shandong. And it's the second highest in most of Shandong, north Henan, eastern and southern Shanxi, and north Jiangsu area, where effective measures should be taken to reduce the detriment of wheat aphids.

Discrimination of goat, buffalo, and yak milk from different livestock, regions, and lactation using microelement contents

This study aims at investigating whether the livestock, lactation stage, or geographical origin of specialty milk in China could be classified by the elemental contents. Samples of goat, buffalo, and yak milk were collected from main production provinces in China and the contents of nine elements in milk from different livestock, regions, and lactation stages were determined. Statistical analysis indicated that the contents of Mn, Cu, As, Se, Cs, and Mo in mature milk were significantly different between the three livestock (p<0.05). The trends of Mn and Cs contents of the goat milk and buffalo milk increased first and then decreased gradually during lactation. The contents of Se, Cs, Ba, and Mo in mature milk of three livestock were significantly different between the three regions (p<0.05). The result of linear discriminant analysis (LDA) and partial least squares discrimination analysis (PLS-DA) showed that the total correct classification rates in different livestock for mature milk reached 86.7 and 90%. For goat milk, the total correct classification rates of different lactations and regions reached 88.9 and 77.8% for LDA (100 and 87.5% for PLS-DA), and followed by yak milk of different regions which achieved 88.9% for LDA (88.9% for PLS-DA). In summary, the microelements in milk showed a significant correlation with livestock, region, and lactation of goat, buffalo, and yak milk. The elemental fingerprints combined with the LDA could be potential for classifying the livestock, lactation stage, and geographical origin of milk. PRACTICAL APPLICATION: According to study the contents of miroelements in milk from different livestock, regions, and lactation stages, provide evidence and support for classifying the livestock, lactation stage, and geographical origin of milk.

Dynamic evolution analysis of recreational fisheries development in China

AbstractUnderstanding the dynamic spatial distribution characteristics and evolving trends in recreational fisheries development is of great importance for formulating policy for responsibly managing recreational fisheries. However, regional economic differences among China's recreational fisheries have yet to be examined and quantified. In this study, a methodological approach applies a series of techniques, including Kernel density estimates, Gini coefficients and Theil indexes, to provide a comprehensive analysis of the dynamic distribution and evolution of recreational fisheries in China. Results showed that recreational fisheries in China have been developing rapidly since the early 21st Century. The total economic value of recreational fisheries in China increased from 5.4 billion Yuan in 2003 to 90.2 billion Yuan in 2018. However, there is a serious imbalance of development of recreational fisheries between regions. Specifically, the combined economic value of recreational fisheries in the main provinces of Shandong, Hubei and Guangdong accounted for 53.4% of recreational value for the whole country, whereas the combined contribution for the bottom 20 of the 31 provinces in the country together accounted for only 10.1%. Analysis of temporal variation at four points in time by kernel density estimation revealed that the development of recreational fisheries exhibited a polarised tendency both among the provinces within the eastern, central and western regions and among the 31 provinces of China. Based on the results of the Theil index decomposition, the overall differences in China's recreational fisheries economy mostly came from differences within each region, which accounted for over 90% of the overall difference. This study provided a means to understand and visualise how key dimensions of recreational fisheries development vary within each region and within the 31 provinces of China, and provides a basis for making short‐term and long‐term policies aimed at promoting coordinated and sustainable development of recreational fisheries in China.

Bioavailable Strontium, Human Paleogeography, and Migrations in the Southern Andes: A Machine Learning and GIS Approach

The Andes are a unique geological and biogeographic feature of South America. From the perspective of human geography, this mountain range provides ready access to highly diverse altitudinally arranged ecosystems. The combination of a geologically and ecologically diverse landscape provides an exceptional context to explore the potential of strontium isotopes to track the movements of people and the conveyance of material culture. Here we develop an isotopic landscape of bioavailable strontium (87Sr/86Sr) that is applied to reconstruct human paleogeography across time in the southern Andes of Argentina and Chile (31°–34°S). These results come from a macro-regional sampling of rodents (N = 65) and plants (N = 26) from modern and archeological contexts. This “Southern Andean Strontium Transect” extends over 350 km across the Andes, encompassing the main geological provinces between the Pacific coast (Chile) and the eastern lowlands (Argentina). We follow a recently developed approach to isoscape construction based on Random Forest regression and GIS analysis. Our results suggest that bioavailable strontium is tightly linked with bedrock geology and offers a highly resolved proxy to track human paleogeography involving the levels of territories or daily mobility and anomalous events that disrupt home ranges, such as migration. The southern Andes provide an ideal geological setting to develop this approach, since the geological variation in rock age and composition produces distinctive isotopic signatures for each main biogeographical region. Finally, we apply this framework to a set of results from human remains from the Uspallata Valley in Mendoza (Argentina), to assess the incidence of migration in the key period of the consolidation of agropastoral economies between AD 800 and 1400. The application of the isoscape to the values from human remains confirms the persistence of human groups with relatively restricted territories encompassing Uspallata and the adjacent Precordillera between AD 800 and 1500. We also identify a pulse of human migration between AD 1280 and 1420, shortly preceding the Inka conquest. Looking forward, we expect to converge with ongoing efforts in South America to build a continental research framework to track the movement of people, animals, and artifacts across space and time.

Diversity and Virulence of Streptomyces spp. Causing Potato Common Scab in Prince Edward Island, Canada.

Common scab (CS) is a potato disease that significantly decreases the market value of potato tubers after the development of necrotic lesions on their surface. Streptomyces scabiei is the main causal agent of CS; however, other closely related species, including S. acidiscabies and S. turgidiscabies, have also been shown to cause the disease. In this study, we characterized the genetic and phenotypic diversity of Streptomyces spp. causing CS in Prince Edward Island, the main potato-producing province in Canada. Two hundred and ninety-six pathogenic Streptomyces spp. isolates were retrieved from diseased tubers harvested from six fields located across a longitudinal geographical gradient. Genome fingerprinting analyses using repetitive elements PCR (ERIC- and BOX-PCR) revealed 14 distinct genetic groups. Thirteen groups were taxonomically affiliated with S. scabiei, whereas the fourteenth group was affiliated with S. acidiscabies. Their geographical distribution was characterized and revealed that on average between six and eight different genetic groups were detected per field, with variable abundance. Virulence assays showed strong differences in virulence between the genetic groups, ranging from low to highly virulent. Interestingly, pathogenic Streptomyces spp. populations in each field seem to be dominated by the most virulent genetic groups. The results obtained will contribute to better understanding of the population dynamic of pathogenic Streptomyces spp. causing CS of potato and promoting the development of more efficient detection and intervention tools to manage this important potato disease.

Peninsular Malaysia transitional geodynamic process from Gondwana to Pangaea: New constraints from 500 to 200 Ma magmatic zircon U-Pb ages and Hf isotopic compositions

The geodynamic process from the evolution of supercontinent has distinct isotope characteristics explorable using zircon Hf isotopic composition. Since Peninsular Malaysia associates with Gondwana dispersal and Pangaea formation, analyzing the U-Pb and Hf-isotopic content of its 500–200 Ma magmatic zircon could reveal the signal left by the transitional geodynamic process between the supercontinents. We collected two groups of magmatic rocks from West Malaya: Ordovician meta-volcanics (n = 8), and Triassic Main Range granitoid province (MRGP) (n = 6); and three groups from East Malaya: Carboniferous meta-volcanics (n = 2), Permian-Triassic Eastern granite province (EGP) (n = 6), and Permian-Triassic EGP volcanics (n = 8). Difference in magmatic zircon Hf isotopic crustal model ages uphold the previous rationale which separates Peninsular into two blocks: West Malaya (part of Sibumasu terrane) magmatic zircon Hf isotopic crustal model ages (Average TDM2: 1.3 Ga) are older than East Malaya (part of Chanthaburi-Sukhothai-Lincang arc of Indochina terrane) (Average TDM2: 0.9 Ga). During the final assembly of Gondwana from 500 to 450 Ma, West Malaya and East Malaya were at the outboard of Gondwana Proto-Tethys margin. The shift of East Malaya zircon Hf array towards higher εHf(t) (external orogenic system) after ca.370 Ma may infers Paleo-Tethys ocean broadening and East Malaya separation from Gondwana. The 370–350 Ma juvenile zircon Hf isotopic composition in East Malaya is a significant improvement over radiolarian age to show the broadening and subduction of the Paleo-Tethys ocean between the two terranes. After ca.280 Ma, East Malaya zircon Hf array shifted towards lower εHf(t) (internal orogenic system). Coinciding with the Indosinian collision at ca.230 Ma, crustal reworking signal increases in both blocks, signifying the end in Peninsular Malaysia Gondwana to Pangaea transitional geodynamic process. As the Paleo-Tethys segment was completely subducted after 230 Ma, the peninsular crustal thickening starts from 230 to 218 Ma. The post-collision phase would begin at ca.215 Ma.

Concentrations of Total As and As Speciation in Chinese Rice Wine and Associated Risk Assessment in Main Producing Provinces

Concentrations of Total As and As Speciation in Chinese Rice Wine and Associated Risk Assessment in Main Producing Provinces

Radiogenic heat production of S-type and I-type granite rocks in Bangka Island, Indonesia

Radiogenic heat production (RHP) has been investigated from widely types of rocks based on regional setting and metamorphism grade. In this study, we analyze the abundance of heat producing elements (U, Th, K) and Radiogenic Heat Production (RHP) on I-type and S-type granite rocks in Bangka Island, one of the main provinces in Tin Belt Island. The average U, Th and K concentrations for both S-type and I-types granite are 10.27 ppm, 79.6 ppm, 3.1% and 87.79 ppm, 99.2 ppm and 1.93 % respectively. The highest concentration of U (681.22 ppm) and Th (99.2 ppm) are found in Pangkal Pinang and K (3.79%) in West Bangka. We analyze that RHP average for I-type granite is higher with 27.87 (N=17, range from 12.97 to 550.28) than S-type with 8.43 (N=11, range from 4.93 to 12.64). The Th/U ratio shows an exponential correlation with RHP and classifies S-type granite tectonic discriminant as continental collision and I-type granite as continental arc.

Lipid Compositions and Geographical Discrimination of 94 Geographically Authentic Wheat Samples Based on UPLC-MS with Non-Targeted Lipidomic Approach.

Wheat is the staple food for the world’s major populations. However, chemical characters of geographically authentic wheat samples, especially for the lipids, have not been deeply studied. The present research aimed to investigate lipid compositions of Chinese wheat samples and clarify the major markers that contribute to the geographical differences. A total of 94 wheat samples from eight main wheat-producing provinces in China were evaluated to differentiate their lipid compositions. Based on the data collected from ultra-high-performance-liquid-chromatography tandem time-of-flight mass spectrometry (UPLC-Q/TOF MS), an optimized non-targeted lipidomic method was utilized for analyses. As the results, 62 lipid compounds, including fatty acids, phospholipids, galactolipids, triglycerides, diglycerides, alkylresorcinol, and ceramide were tentatively identified. Partial least squares discriminant analysis (PLS-DA) demonstrated a more satisfying performance in distinguishing wheat samples from different origins compared with principal component analysis (PCA). Further, the abundances of triglycerides and glycerophospholipids with more unsaturated fatty acids were found greater in wheat samples from northern origins of China, while more glycolipids and unsaturated fatty acids arose in southern original wheat samples. These findings describe the lipid profiles of wheat samples in China and could contribute to the quality and safety control for the wheat flour products.

Visitor Profiles of Coastal and Marine Tourism Sites in the Eastern Cape, South Africa

Current research on Coastal and Marine Tourism (CTM) in South Africa focuses on two main coastal tourism provinces (KwaZulu-Natal and Western Cape) as well as specific CMT activities such as whale watching and shark cage diving. This study, therefore, contributes to the body of knowledge on CMT by focusing on the Eastern Cape and undertaking a provincial level analysis. Coastal and Marine Tourism location visitor profiles in terms of socio-economic profile, types of CMT visitors, types of CMT activities participated and future interest in the Eastern Cape, South Africa. CMT encompasses activities and resources in and near coastal and marine areas that attract visitors who participate in a range of active and passive business, adventure, leisure and recreational activities that generate socio-economic and environmental benefits. A quantitative approach is adopted, drawing on 700 visitor surveys that were conducted at purposively selected CMT locations in the Eastern Cape. Visitors were from a range of socio-economic backgrounds. There were high levels of participation in CMT activities, especially coastal leisure and recreational activities. Results indicate increased CMT location visitation demand. From a sustainability and responsible tourism perspective, understanding who visits CMT sites assists in ensuring effective planning to manage demand and protect/ conserve coastal and marine resources.

Petrogenesis of the Main Range and Eastern Province granites in eastern Myanmar: New insights from zircon U–Pb ages and Sr–Nd isotopes

The Main Range and Eastern Provinces are two major granite belts in Southeast Asia. These granite belts extend southward from the southeastern Tibetan Plateau to Myanmar, and through Thailand into Peninsular Malaysia. They are interpreted to represent the magmatic expression of the closure of the Paleo-Tethys from the Permian to the Triassic. Myanmar lies in the heart of these granite belts. The Kyaing Tong and Tachileik granites in the far east of Myanmar are important components of the granite belts of Southeast Asia; however, due to the lack of reliable geochronology within eastern Myanmar, delineation of the Main Range and Eastern Province belts in this region is very poorly constrained. Here we present new zircon U–Pb age, whole-rock composition, and Sr–Nd isotope data from the Kyaing Tong and Tachileik granites from eastern Myanmar to address this geological problem. Measured ages of 207–216 Ma from the Kyaing Tong granites imply that they are a northern extension of the Main Range Province, whereas the Tachileik granites yield ages of 246–250 Ma, which suggests that they are the northern extension of the Eastern Province granite belt. Both belts in eastern Myanmar comprise biotite monzogranites and granodiorites and show similar geochemical features, such as having a high aluminum saturation index and an unfractionated composition. The granites from both provinces show enrichment in light rare earth elements (REE) and negative Eu anomalies. All samples demonstrate characteristic negative Ba, Nb, Ta, Sr and Ti anomalies, and a positive Pb anomaly, when plotted on spidergrams. The Kyaing Tong granites have high and variable initial 87Sr/86Sr ratios (0.717735–0.731271), negative εNd (t = 215 Ma) values (−14.2 to −10.4), and old TDM2 ages. Similarly, the Tachileik granites have high and variable initial 87Sr/86Sr ratios (0.715336–0.722712), negative εNd (t = 250 Ma) values (−12.4 to −11.3), and old TDM2 ages. Sr–Nd isotope values show that these granites may be generated by mixing of two end-member lithologies: amphibolite and schist of the Lancang Group, which represents the lower crust of the Indochina block. We consider that both the Kyaing Tong and Tachileik granites are of I-type affinity. They were derived from partial melting of the amphibolite and underwent assimilation of schist. Our petrogenetic and zircon U–Pb age data support models that relate the Eastern Province granites to continental arc during the Permian and syn-collisional magmatism in the Early Triassic, and the Main Range Province granites to post-collisional magmatism during the Middle to Late Triassic.

Impact of Climate Change on Surface Stirring and Transport in the Mediterranean Sea

AbstractUnderstanding how climate change will affect oceanic fluid transport is crucial for environmental applications and human activities. However, a synoptic characterization of the influence of climate change on mesoscale stirring and transport in the surface ocean is missing. To bridge this gap, we exploit a high‐resolution, fully coupled climate model of the Mediterranean basin using a Network Theory approach. We project significant increases of horizontal stirring and kinetic energies in the next century, likely due to increments of available potential energy. The future evolution of basin‐scale transport patterns hints at a rearrangement of the main hydrodynamic provinces, defined as regions of the surface ocean that are well mixed internally but with minimal cross‐flow across their boundaries. This results in increased heterogeneity of province sizes and stronger mixing in their interiors. Our approach can be readily applied to other oceanic regions, providing information for the present and future marine spatial planning.

Database of epidemic trends and control measures during the first wave of COVID-19 in mainland China

ObjectivesIn this data collation study, we aimed to provide a comprehensive database describing the epidemic trends and responses during the first wave of coronavirus disease 2019 (COVID-19) throughout the main provinces in China. MethodsFrom mid-January to March 2020, we extracted publicly available data regarding the spread and control of COVID-19 from 31 provincial health authorities and major media outlets in mainland China. Based on these data, we conducted descriptive analyses of the epidemic in the six most-affected provinces. ResultsSchool closures, travel restrictions, community-level lockdown, and contact tracing were introduced concurrently around late January but subsequent epidemic trends differed among provinces. Compared with Hubei, the other five most-affected provinces reported a lower crude case fatality ratio and proportion of critical and severe hospitalised cases. From March 2020, as the local transmission of COVID-19 declined, switching the focus of measures to the testing and quarantine of inbound travellers may have helped to sustain the control of the epidemic. ConclusionsAggregated indicators of case notifications and severity distributions are essential for monitoring an epidemic. A publicly available database containing these indicators and information regarding control measures is a useful resource for further research and policy planning in response to the COVID-19 epidemic.

Geographical reconstruction of the SARS‐CoV‐2 outbreak in Lombardy (Italy) during the early phase

The first identification of autochthonous transmission of SARS‐CoV‐2 in Italy was documented by the Laboratory of Clinical Microbiology, Virology and Bioemergencies of L. Sacco Hospital (Milano, Italy) on 20th February 2020 in a 38 years old male patient, who was found positive for pneumonia at the Codogno Hospital. Thereafter Lombardy has reported the highest prevalence of COVID‐19 cases in the country, especially in Milano, Brescia and Bergamo provinces. The aim of this study was to assess the potential presence of different viral clusters belonging to the six main provinces involved in Lombardy COVID‐19 cases in order to highlight peculiar province‐dependent viral characteristics. A phylogenetic analysis was conducted on 20 full length genomes obtained from patients addressing to several Lombard hospitals from February 20th to April 4th, 2020, aligned with 41 Italian viral genome assemblies available on GISAID database as of 30th March, 2020: two main monophyletic clades, containing 8 and 53 isolates, respectively, were identified. Noteworthy, Bergamo isolates mapped inside the small clade harbouring M gene D3G mutation. The molecular clock analysis estimated a cluster divergence approximately one month before the first patient identification, supporting the hypothesis that different SARS‐CoV‐2 strains had spread worldwide at different times, but their presence became evident only in late February along with Italian epidemic emergence. Therefore, this epidemiological reconstruction suggests that virus initial circulation in Lombardy was ascribable to multiple introduction. The phylogenetic reconstruction robustness, however, will be improved when more genomic sequences are available, in order to guarantee a complete epidemiological surveillance.

Meteorological variables associated with the temporal oviposition rate of Aedes aegypti (Diptera: Culicidae) in Resistencia city, Chaco province, Northeastern Argentina

Aedes aegypti is the main vector of dengue virus in South America. In the last fifteen years, Argentina has suffered three large dengue outbreaks: one in 2009, another one in 2016 and the current 2020 outbreak, with 26,000, 66,000 and more than 43,000 confirmed cases, respectively. These outbreaks are associated with the circulation of the virus in neighboring countries due to the constant movement of people across the frontier. In 2009, the main province affected was Chaco province, with 11,037 confirmed cases (50% of total cases). Thus, the aim of this study was to characterize the temporal oviposition rate of Aedes aegypti in Resistencia, the capital city of this province, in relation to meteorological variables. Mosquitoes were sampled weekly, from April 2015 to March 2017, using ovitraps located in houses randomly selected within the urban area. Oviposition rate was evaluated by means of the total number of eggs collected per week and the proportion of positive ovitraps per week. The coefficient of variation for these two indicators was estimated for the whole study period and then compared using the Wilcoxon Pair test. A generalized linear model (GLM) was performed to infer association between meteorological variables and oviposition rate without time lag and with a time lag of 1 to 4 weeks, considering the biology of this mosquito species. Comparisons between the coefficient of variation of egg number versus the proportion of positive ovitraps showed significant differences, being the former more variable than the latter. The most significant time lag was 2 weeks for the minimum temperature. The number of Ae. aegypti eggs increased 4.05 times when the minimum temperature increased 1°C two weeks before, and decreased 0.69 times with an increase of 1 unit in relative humidity. No eggs were collected when the temperature was below 8°C. The oviposition rate was associated with the increase in the critical minimum temperature (over 8°C) and the weekly frequency of precipitation and dissociated with relative humidity. The maximum oviposition rate was recorded between November and January of both years. The GLM could not explain the relation between meteorological variables and the proportion of positive ovitraps. The peaks of Ae. aegypti egg abundance occurred simultaneously with dengue autochthonous cases recorded in Chaco province, resulting in a good indicative of the period of greatest epidemiological risk.