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1.
Water Sci Technol ; 81(10): 2092-2108, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32701489

RESUMO

Mesocellular foam (MCF) silica molecular sieve material was successfully synthesized using a hydrothermal method. X-ray diffraction, infrared spectroscopy, low nitrogen adsorption-desorption, scanning electron microscopy, and transmission electron microscopy (TEM) characterization techniques were used to characterize the material. Low temperature nitrogen adsorption-desorption method showed that pore size of the synthesized MCF was 12 nm. TEM study showed that the synthesized MCFs had honeycomb structure pores, which can be good for the absorbance of dye organic macromolecule substances. This work studied the adsorption of crystal violet by MCF and the results showed that when the adsorptive conditions were pH = 9.0, MCF:crystal violet = 150:1, and when the contact time was 10 min at room temperature of 25 ± 1 °C, the adsorption rate reached 99.71% and adsorption capacity was 6.646 mg/g. This study found that the adsorption is a Freundlich type, it is a multimolecular layer adsorption, and it belongs to the pseudo-second-order kinetic model. According to the ΔG0 obtained from adsorption thermodynamics, when the temperature is 25-40 °C, the adsorption enthalpy change ΔH0 = -25.65 kJ/mol, ΔG0 < 0, the adsorption is an exothermic reaction and can spontaneously occur. The adsorption entropy change ΔS0 = 5.54 J/(mol·K) and the entropy of system increased.


Assuntos
Violeta Genciana , Dióxido de Silício , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Temperatura , Termodinâmica
3.
Environ Monit Assess ; 192(8): 525, 2020 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-32676945

RESUMO

The environmental quality of the learning environment is a critical element for good health and well-being among beneficiaries of tertiary institutions, ultimately influencing staff productivity and learning performance of students. High population densities, inefficient resource use and unique microenvironments within tertiary institutions can result in myriad environmental challenges which require targeted solutions. An environmental gap analysis is a pragmatic and evidence-based approach that can be used to evaluate the environmental quality of institutions through the provision of baseline data and comparison to relevant environmental standards. In this study, an environmental gap analysis was conducted at university campus, where air, noise, water and soil data were collected for 12 weeks at indoor and outdoor sites. The data obtained were averaged, graphed and benchmarked using relevant local and international guidelines to identify gaps. Additionally, the data were tested using two-way analysis of variance (ANOVA). Generally, the levels of parameters monitored were acceptable and within respective local and international guidelines; however, air temperature and relative humidity of the indoor cafeteria as well as turbidity of tap water were not in conformance with guidelines. Improvements in maintenance of ventilation systems and water distribution infrastructure are recommended along with further investigations of drinking water and indoor air quality at the campus. The insight obtained in this study provided important baseline data, in an area where there is a dearth of information, from which deficiencies can be identified and evidence-based recommendations can be made.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Monitoramento Ambiental , Ar Condicionado , Humanos , Temperatura , Universidades
4.
Mem Inst Oswaldo Cruz ; 115: e200218, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32696917

RESUMO

BACKGROUND: Southeast Brazil has recently experienced a Yellow Fever virus (YFV) outbreak where the mosquito Haemagogus leucocelaenus was a primary vector. Climatic factors influence the abundance of mosquito vectors and arbovirus transmission. OBJECTIVES: We aimed at describing the population dynamics of Hg. leucocelaenus in a county touched by the recent YFV outbreak. METHODS: Fortnightly egg collections with ovitraps were performed from November 2012 to February 2017 in a forest in Nova Iguaçu, Rio de Janeiro, Brazil. The effects of mean temperature and rainfall on the Hg. leucocelaenus population dynamics were explored. FINDINGS: Hg. leucocelaenus eggs were continuously collected throughout the study, with a peak in the warmer months (December-March). The climatic variables had a time-lagged effect and four weeks before sampling was the best predictor for the positivity of ovitraps and total number of eggs collected. The probability of finding > 50% positive ovitraps increased when the mean temperature was above 24ºC. The number of Hg. leucocelaenus eggs expressively increase when the mean temperature and accumulated precipitation surpassed 27ºC and 100 mm, respectively, although the effect of rainfall was less pronounced. MAIN CONCLUSIONS: Monitoring population dynamics of Hg. leucocelaenus and climatic factors in YFV risk areas, especially mean temperature, may assist in developing climate-based surveillance procedures to timely strengthening prophylaxis and control.


Assuntos
Culicidae/virologia , Florestas , Insetos Vetores/virologia , Dinâmica Populacional , Febre Amarela , Vírus da Febre Amarela/isolamento & purificação , Animais , Brasil , Culicidae/classificação , Insetos Vetores/classificação , Estações do Ano , Temperatura , Vírus da Febre Amarela/genética
5.
Ying Yong Sheng Tai Xue Bao ; 31(7): 2352-2362, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32715701

RESUMO

It is of great significance for the sustainable development of regional agriculture to understand the changes of agricultural climate resources during the growth period of local main crops. Based on data from 15 meteorological stations in tobacco planting area of Panxi region, Sichuan, from 1961 to 2017, the average temperature, diurnal temperature range, water deficit, and radiation were used to analyze the temporal and spatial distribution of agricultural climate resources such as light, temperature, and water in the whole growth period and each growth stages respectively. From 1961 to 2017, the average temperature of tobacco during the whole growth period gradually decreased from south to north in Panxi, while temperature showed an increasing trend in most areas. The area with significantly increased temperature accounted for 54.5% of the total planting area. The diurnal temperature range in most area of the eastern Panxi and some of the central Panxi showed an upward trend, and these areas accounted for 76.4% of the whole Panxi region. Water deficit gradually decreased from south to north, with an increasing trend in the whole region. The radiation during the growth stage of tobacco was high in the southwest and low in the northeast, and the climatic tendency was positive values in the southwest. During the study period, average temperature was the highest in the period from vigorous growth to the beginning of maturity, with an overall upward trend. The diurnal temperature rage and water deficit were the highest in transplanting squatting seedling stage. Radiation was the highest at the beginning of maturity, which increased slightly at the beginning of seedling growth.


Assuntos
Mudança Climática , Tabaco , Agricultura , China , Produtos Agrícolas , Temperatura
6.
Ying Yong Sheng Tai Xue Bao ; 31(7): 2457-2463, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32715713

RESUMO

Studies on variations in chilling and heat accumulation in apple trees and their effects on first flowering date under climate change are important for guiding apple planting and productions. In this study, we carried out experiments in representative stations of apple planting areas in the northern China, including Fushan of Shandong, Wanrong of Shanxi, Xifeng of Gansu and Akesu of Xinjiang. The first flowering data and hourly temperature data during 1996-2018 were used to calculate the daily chilling and heat accumulation units by applying the dynamic model and growing degree hour model. Partial least squares regression (PLS) correlated daily chilling and heat units with the first flowering dates was used to identify the chilling and heat accumulation periods for apple flowering. We evaluated the impacts of temperatures during these periods on apples' flowering. Our results showed that the chilling accumulation period of apple trees in the examined sites started at October 1, ended in late February or mid-March, with chilling accumulations of 74.1-89.3 CP (chill portion). The heat accumulation periods were from late January to the first flowering dates with the heat accumulation of 4010-5770 GDH (growing degree hour). The chilling accumulation at Xifeng and Akesu was correlated positively with mean temperature during the respective accumulation period, with 3.8 and 5.0 CP enhancement following 1 ℃ increase during the accumulation period. Heat accumulation at all stations correlated positively with mean temperature during the respective accumulation period, with 725-967 GDH enhancement following a 1 ℃ increase during the accumulation period. Compared to the effects of chilling accumulation on tree flowering, the first flowering data of apples in the main planting areas were mainly affected by mean temperature during the heat accumulation period. Climate warming is beneficial for apple blossom and production in the areas with low mean temperature during the chilling accumulation period.


Assuntos
Malus , China , Flores , Temperatura Alta , Estações do Ano , Temperatura
7.
Water Sci Technol ; 81(7): 1479-1493, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32616700

RESUMO

Finding an appropriate adsorbent with high adsorption capacity, quick adsorption kinetics and easy regeneration was crucial to the removal of gallic acid (GA) from water and wastewater. Our aims were to investigate whether a magnetic ion exchange (MIEX) resin had the three merits mentioned above, and investigate the feasibility of GA adsorption on MIEX resin, and the adsorption kinetics, equilibrium, thermodynamics, regeneration and mechanism using batch tests. The uptake of GA increased with increasing GA concentration. The GA concentration influenced the time needed to reach equilibrium, but the adsorption could be completed within 120 min. Elevating temperature facilitated the GA removal. The removal percent remained above 95.0% at pH 5.0-11.0. Carbonate and bicarbonate promoted the GA removal; conversely chloride, sulfate and nitrate restrained the GA removal significantly. The adsorption kinetics could be fitted well with the pseudo second-order model, and the film diffusion governed the whole adsorption rate. The equilibrium data followed the Redlich-Peterson isotherm model. The adsorption was a spontaneous, endothermic and entropy driven process. The ion exchange dominated the removal mechanism. The spent MIEX resin was well regenerated by sodium chloride. Therefore, MIEX resin is a potential adsorbent for removing GA quickly and efficiently from water and wastewater.


Assuntos
Ácido Gálico , Poluentes Químicos da Água/análise , Adsorção , Concentração de Íons de Hidrogênio , Resinas de Troca Iônica , Cinética , Fenômenos Magnéticos , Soluções , Temperatura , Termodinâmica
8.
Water Sci Technol ; 81(8): 1597-1605, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32644953

RESUMO

There is a strongly growing interest for wastewater heat recovery (WWHR) in Sweden and elsewhere, but a lack of adequate tools to determine downstream impacts due to the associated temperature drop. The heat recovery potential and associated temperature drop after heat recovery on a building level is modelled for a case study in Linköping, Sweden. The maximum temperature drop reaches 4.2 °C, with an annual recovered heat of 0.65 kWh · person-1 · day-1. Wastewater temperature out from the heat exchanger was 18.0 °C in winter at the lowest. The drinking water source type can be an important factor when considering wastewater heat recovery.


Assuntos
Temperatura Alta , Águas Residuárias , Estações do Ano , Suécia , Temperatura
9.
Nature ; 583(7815): 242-248, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32641817

RESUMO

Enhanced silicate rock weathering (ERW), deployable with croplands, has potential use for atmospheric carbon dioxide (CO2) removal (CDR), which is now necessary to mitigate anthropogenic climate change1. ERW also has possible co-benefits for improved food and soil security, and reduced ocean acidification2-4. Here we use an integrated performance modelling approach to make an initial techno-economic assessment for 2050, quantifying how CDR potential and costs vary among nations in relation to business-as-usual energy policies and policies consistent with limiting future warming to 2 degrees Celsius5. China, India, the USA and Brazil have great potential to help achieve average global CDR goals of 0.5 to 2 gigatonnes of carbon dioxide (CO2) per year with extraction costs of approximately US$80-180 per tonne of CO2. These goals and costs are robust, regardless of future energy policies. Deployment within existing croplands offers opportunities to align agriculture and climate policy. However, success will depend upon overcoming political and social inertia to develop regulatory and incentive frameworks. We discuss the challenges and opportunities of ERW deployment, including the potential for excess industrial silicate materials (basalt mine overburden, concrete, and iron and steel slag) to obviate the need for new mining, as well as uncertainties in soil weathering rates and land-ocean transfer of weathered products.


Assuntos
Agricultura , Dióxido de Carbono/isolamento & purificação , Produtos Agrícolas , Sedimentos Geológicos/química , Aquecimento Global/prevenção & controle , Objetivos , Silicatos/química , Atmosfera/química , Brasil , China , Política Ambiental/economia , Política Ambiental/legislação & jurisprudência , Aquecimento Global/economia , Índia , Ferro/isolamento & purificação , Mineração , Política , Probabilidade , Silicatos/isolamento & purificação , Aço/isolamento & purificação , Temperatura , Fatores de Tempo , Estados Unidos
10.
Infect Dis Poverty ; 9(1): 87, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32650838

RESUMO

BACKGROUND: The new coronavirus disease COVID-19 began in December 2019 and has spread rapidly by human-to-human transmission. This study evaluated the transmissibility of the infectious disease and analyzed its association with temperature and humidity to study the propagation pattern of COVID-19. METHODS: In this study, we revised the reported data in Wuhan based on several assumptions to estimate the actual number of confirmed cases considering that perhaps not all cases could be detected and reported in the complex situation there. Then we used the equation derived from the Susceptible-Exposed-Infectious-Recovered (SEIR) model to calculate R0 from January 24, 2020 to February 13, 2020 in 11 major cities in China for comparison. With the calculation results, we conducted correlation analysis and regression analysis between R0 and temperature and humidity for four major cities in China to see the association between the transmissibility of COVID-19 and the weather variables. RESULTS: It was estimated that the cumulative number of confirmed cases had exceeded 45 000 by February 13, 2020 in Wuhan. The average R0 in Wuhan was 2.7, significantly higher than those in other cities ranging from 1.8 to 2.4. The inflection points in the cities outside Hubei Province were between January 30, 2020 and February 3, 2020, while there had not been an obvious downward trend of R0 in Wuhan. R0 negatively correlated with both temperature and humidity, which was significant at the 0.01 level. CONCLUSIONS: The transmissibility of COVID-19 was strong and importance should be attached to the intervention of its transmission especially in Wuhan. According to the correlation between R0 and weather, the spread of disease will be suppressed as the weather warms.


Assuntos
Número Básico de Reprodução , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/transmissão , Pneumonia Viral/epidemiologia , Pneumonia Viral/transmissão , Betacoronavirus/patogenicidade , China/epidemiologia , Cidades , Infecções por Coronavirus/prevenção & controle , Transmissão de Doença Infecciosa/prevenção & controle , Transmissão de Doença Infecciosa/estatística & dados numéricos , Humanos , Umidade , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Análise de Regressão , Temperatura
11.
mSphere ; 5(4)2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32611701

RESUMO

Coronavirus disease 2019 (COVID-19) was first identified in China in late 2019 and is caused by newly identified severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Previous studies had reported the stability of SARS-CoV-2 in cell culture media and deposited onto surfaces under a limited set of environmental conditions. Here, we broadly investigated the effects of relative humidity, temperature, and droplet size on the stability of SARS-CoV-2 in a simulated clinically relevant matrix dried on nonporous surfaces. The results show that SARS-CoV-2 decayed more rapidly when either humidity or temperature was increased but that droplet volume (1 to 50 µl) and surface type (stainless steel, plastic, or nitrile glove) did not significantly impact decay rate. At room temperature (24°C), virus half-life ranged from 6.3 to 18.6 h depending on the relative humidity but was reduced to 1.0 to 8.9 h when the temperature was increased to 35°C. These findings suggest that a potential for fomite transmission may persist for hours to days in indoor environments and have implications for assessment of the risk posed by surface contamination in indoor environments.IMPORTANCE Mitigating the transmission of SARS-CoV-2 in clinical settings and public spaces is critically important to reduce the number of COVID-19 cases while effective vaccines and therapeutics are under development. SARS-CoV-2 transmission is thought to primarily occur through direct person-to-person transfer of infectious respiratory droplets or through aerosol-generating medical procedures. However, contact with contaminated surfaces may also play a significant role. In this context, understanding the factors contributing to SARS-CoV-2 persistence on surfaces will enable a more accurate estimation of the risk of contact transmission and inform mitigation strategies. To this end, we have developed a simple mathematical model that can be used to estimate virus decay on nonporous surfaces under a range of conditions and which may be utilized operationally to identify indoor environments in which the virus is most persistent.


Assuntos
Fômites/virologia , Umidade , Modelos Teóricos , Vírus da SARS/fisiologia , Temperatura , Inativação de Vírus , Poluição do Ar em Ambientes Fechados , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Meia-Vida , Humanos , Pandemias/prevenção & controle , Plásticos , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Porosidade , Saliva/química , Saliva/virologia , Aço Inoxidável , Propriedades de Superfície
12.
Mar Pollut Bull ; 157: 111324, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32658689

RESUMO

Dramatic increases in the release of anthropogenic CO2 and global temperatures have resulted in alterations to seawater carbonate chemistry and metabolisms of marine organisms. There has been recent interest in the effects of these stressors on crustose coralline algae (CCA) because photosynthesis and calcification are influenced by all components of carbonate chemistry. To examine this, a mesocosm experiment was conducted to evaluate photosynthesis, calcification and growth in the temperate CCA Chamberlainium sp. under acidification (doubled CO2), warming (+5 °C), and greenhouse (doubled CO2 and +5 °C) conditions compared to present-day conditions. After 47 days of acclimation to these conditions, productivity was lowest under acidification, although photochemical properties were improved, while respiration was highest under warming. Likewise, growth was lowest under acidification, but this negative response was offset by elevated temperature under greenhouse. Together, these results suggest that warming offsets the negative effects of acidification by creating more suitable conditions for photosynthesis and growth.


Assuntos
Aquecimento Global , Rodófitas , Concentração de Íons de Hidrogênio , Oceanos e Mares , Água do Mar , Temperatura
13.
Mar Pollut Bull ; 157: 111341, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32658699

RESUMO

Several abiotic factors influence the ecological responses of aquatic invertebrates to metal toxicity. We examined the effect of salinity (10, 20, and 30 psu) and temperature (25 and 32 °C) on acute and chronic arsenic (As) toxicity to the euryhaline rotifers, Proales similis and Brachionus ibericus. In general, higher salinities and low temperature resulted in lower arsenic toxicity. The population growth studies indicated that P. similis was more sensitive than B. ibericus to As. Arsenic toxicity intensified the vulnerability of P. similis to B. ibericus competition. Life table parameters decreased with increasing As levels in the medium. Chronic toxicity bioassays were more sensitive than acute toxicity tests for determining the adverse effect of As to rotifers. Our findings provide useful insights on the effect of arsenic on rotifer populations exposed to different temperature and salinity scenarios. Proales similis could be an important complement to brachionid rotifers for marine toxicity bioassays.


Assuntos
Arsênico , Rotíferos , Poluentes Químicos da Água , Animais , Salinidade , Temperatura
14.
Ying Yong Sheng Tai Xue Bao ; 31(2): 381-387, 2020 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-32476329

RESUMO

We used tree rings of Pinus tabuliformis sampled in the Muwang National Forest Park to establish a standardized chronology (STD) and calculated the correlation coefficients between the standardized chronology and climatic factors of Zhen'an meteorological station. With linear regression analysis, we reconstructed the March-April mean maximum temperature of Zhen'an over 165 years from 1853 to 2017. The highest correlation coefficient was observed between the standardized chronology and the March-April mean maximum temperature (r=0.596, n=60, P<0.01). The variance interpretation of the March-April mean maximum temperature reconstruction function was 33.2%, and the reconstruction function and results were credible and reliable. Warm years occurred 25 times and cold years occurred 29 times in the reconstruction sequence. The warm years were more accompanied by flood events, while the cold years were accompanied by more drought events. Temperature fluctuated obviously in the reconstruction sequence, with two cold periods (1902-1917 and 1953-2000) and four warm periods (1868-1892, 1917-1937, 1941-1953 and 2001-2012). The obvious periodic variations of 2-7, 8-15, 18-28, 75-96, and 100-125 years were found in the reconstruction sequence, in which the quasi-113, 88 and 22 years were the first, second and third main periods, respectively. These variations might potentially be the fingerprints of some climate change forces such as solar activity, monsoon and EI Niño-Southern Oscillation (ENSO) activity.


Assuntos
Pinus , China , Mudança Climática , Florestas , Temperatura
15.
J Environ Manage ; 268: 110709, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32510443

RESUMO

Model evaluation is a critical component in the development and applications of environmental modeling systems. Conventional metrics such as Pearson product-moment correlation coefficient (r), root-mean-square error (RMSE), and mean absolute error (MAE), albeit process-based and limited to point-to-point statistical comparison, have been widely used in model evaluations. In this study, we propose a network-based toolkit for evaluation of model performance and multi-model comparisons with applications to weather prediction and climate modeling. The model outputs are topologically quantified through a range of network metrics to provide a holistic measure of system dynamics. We first use this toolkit to evaluate the performance of air temperature simulated by the Weather Research and Forecasting model with station measurements over the contiguous United States (CONUS). Results of network analysis suggest a good match between simulation and measurement, as indicated by conventional metrics (r, RMSE, and MAE) as well. The sensitivity of these network metrics is then analyzed based on CONUS station measurements with additive random errors using Monte Carlo simulations. Network metrics show more sensitive and highly nonlinear responses to increasing random errors as compared to conventional ones. Moreover, we use the new toolkit for intercomparison of the downscaled historical air temperature outputs from four global climate models. The similarity in both metrics and spatial structure highlights the capability of network analysis for capturing system dynamics in models alike. The network theory is therefore promising for evaluation and intercomparison of various environmental modeling systems with complex dynamics.


Assuntos
Clima , Tempo (Meteorologia) , Previsões , Temperatura
16.
Sci Total Environ ; 727: 138558, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32498208

RESUMO

Stable isotopes in wood lignin methoxyl groups (δ2HLM and δ13CLM values) have been suggested as valuable complementary paleoclimate proxies. In permafrost forests, tree growth is influenced by multiple factors, however temperature appears to have the strongest impact on tree growth and, therefore, on carbon cycling. To test whether δ2HLM and δ13CLM values of trees from permafrost regions might record climate parameters, two dominant tree species (Larix gmelinii, larch, and Pinus sylvestris var. mongolica, pine) collected from a permafrost forest in China's Greater Hinggan Mountains, were investigated. The two tree species larch and pine covered time spans of 1940 to 2013 and 1870 to 2013, respectively. Results showed significant correlations of pine and larch δ2HLM values and larch δ13CLM values with temperatures and in particular with the mean temperature of the growing season from April to August. However, only weak correlations of δ2HLM and δ13CLM values with moisture conditions, such as precipitation amount and relative humidity were observed. In addition, species specificity in the climate response was most obvious for δ13CLM values. Compared to a temperature reconstruction based on tree ring width, pine δ2HLM-based reconstruction showed strongest spatial correlations with regional temperature. Therefore, δ2HLM values might be a promising proxy to reconstruct growing-season temperatures in permafrost regions.


Assuntos
Pergelissolo , China , Florestas , Lignina , Temperatura , Árvores , Madeira
17.
J Transl Med ; 18(1): 251, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32576227

RESUMO

BACKGROUND: With the aim of providing a dynamic evaluation of the effects of basic environmental parameters on COVID-19-related death rate, we assessed the correlation between average monthly high temperatures and population density, with death/rate (monthly number of deaths/1 M people) for the months of March (start of the analysis and beginning of local epidemic in most of the Western World, except in Italy where it started in February) and April 2020 (continuation of the epidemic). Different geographical areas of the Northern Hemisphere in the United States and in Europe were selected in order to provide a wide range among the different parameters. The death rates were gathered from an available dataset. As a further control, we also included latitude, as a proxy for temperature. METHODS: Utilizing a publicly available dataset, we retrieved data for the months of March and April 2020 for 25 areas in Europe and in the US. We computed the monthly number of deaths/1 M people of confirmed COVID-19 cases and calculated the average monthly high temperatures and population density for all these areas. We determined the correlation between number of deaths/1 M people and the average monthly high temperatures, the latitude and the population density. RESULTS: We divided our analysis in two parts: analysis of the correlation among the different variables in the month of March and subsequent analysis in the month of April. The differences were then evaluated. In the month of March there was no statistical correlation between average monthly high temperatures of the considered geographical areas and number of deaths/1 M people. However, a statistically significant inverse correlation became significant in the month of April between average monthly high temperatures (p = 0.0043) and latitude (p = 0.0253) with number of deaths/1 M people. We also observed a statistically significant correlation between population density and number of deaths/1 M people both in the month of March (p = 0.0297) and in the month of April (p = 0.0116), when three areas extremely populated (NYC, Los Angeles and Washington DC) were included in the calculation. Once these three areas were removed, the correlation was not statistically significant (p = 0.1695 in the month of March, and p = 0.7076 in the month of April). CONCLUSIONS: The number of COVID-19-related deaths/1 M people was essentially the same during the month of March for all the geographical areas considered, indicating essentially that the infection was circulating quite uniformly except for Lombardy, Italy, where it started earlier. Lockdown measures were implemented between the end of March and beginning of April, except for Italy which started March 9th. We observed a strong, statistically significant inverse correlation between average monthly high temperatures with the number of deaths/1 M people. We confirmed the data by analyzing the correlation with the latitude, which can be considered a proxy for high temperature. Previous studies indicated a negative effect of high climate temperatures on Sars-COV-2 spreading. Our data indicate that social distancing measure are more successful in the presence of higher average monthly temperatures in reducing COVID-19-related death rate, and a high level of population density seems to negatively impact the effect of lockdown measures.


Assuntos
Infecções por Coronavirus/mortalidade , Meio Ambiente , Mortalidade , Pneumonia Viral/mortalidade , Temperatura , Betacoronavirus/fisiologia , Infecções por Coronavirus/epidemiologia , District of Columbia/epidemiologia , Monitoramento Ambiental/métodos , Europa (Continente)/epidemiologia , Geografia , Humanos , Itália/epidemiologia , Los Angeles/epidemiologia , Cidade de Nova Iorque/epidemiologia , Pandemias , Pneumonia Viral/epidemiologia , Densidade Demográfica , Comportamento Social
18.
Sci Total Environ ; 735: 139084, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32480143

RESUMO

Elevated CO2 levels have been shown to affect metabolic performance in some coral reef fishes. However, all studies to date have employed stable elevated CO2 levels, whereas reef habitats can experience substantial diel fluctuations in pCO2 ranging from ±50 to 600 µatm around the mean, fluctuations that are predicted to increase in magnitude by the end of the century. Additionally, past studies have often investigated the effect of elevated CO2 in isolation, despite the fact that ocean temperatures will increase in tandem with CO2 levels. Here, we tested the effects of stable (1000 µatm) versus diel-cycling (1000 ± 500 µatm) elevated CO2 conditions and elevated temperature (+2 °C) on metabolic traits of juvenile spiny damselfish, Acanthochromis polyacanthus. Resting oxygen uptake rates (MO2) were higher in fish exposed to stable elevated CO2 conditions when compared to fish from stable control conditions, but were restored to control levels under diel CO2 fluctuations. However, the benefits of diel CO2 fluctuations were diminished at elevated temperature. Factorial aerobic scope showed a similar pattern, but neither maximal MO2 nor absolute aerobic scope was affected by CO2 or temperature. Our results suggest that diel CO2 cycles can ameliorate the increased metabolic cost associated with elevated CO2, but elevated temperature diminishes the benefits of diel CO2 cycles. Thus, previous studies may have misestimated the effect of ocean acidification on the metabolic performance of reef fishes by not accounting for environmental CO2 fluctuations. Our findings provide novel insights into the interacting effects of diel CO2 fluctuations and temperature on the metabolic performance of reef fishes.


Assuntos
Dióxido de Carbono , Água do Mar , Animais , Recifes de Corais , Peixes , Concentração de Íons de Hidrogênio , Temperatura
19.
Sci Total Environ ; 735: 139345, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32480146

RESUMO

Aiming for total nitrogen (TN) pollution control in the urbanized stream, this study proposed and verified a strategy of cultivating and acclimating sulfur-based autotrophic denitrifiers by using river-bottom sediments as seed sludge, and investigated temperature effects on sulfur-based autotrophic denitrification (SAD). With thiosulfate as an electron donor, seven SAD batch reactors were operated and studied at both 15 °C and 30 °C, to compare reactor performance and their microbial community analysis results. In the first batch, three parallel reactors (A1, A2, and A3) were operated at 30 °C for 30 days. The dynamic analysis showed that sequentially decreasing temperature to 20, 15, and 10 °C had significant adverse effects on nitrate-loading rates. In the second batch, two groups of parallel reactors were operated at 30 °C (B1 and B2) and 15 °C (C1 and C2) for 45 days. High TN removal efficiencies (>95%) were achieved in all four reactors, with comparable nitrate loading rates and less nitrite accumulation at 15 °C. High-throughput sequencing revealed that genus Thiobacillus was predominant (66.3-90.0%) in all seven reactors. However, at the operational taxonomic unit level, microbial communities at 15 °C and 30 °C were significantly different, indicating that dissimilar strains were cultivated. Our findings suggested that deliberately cultivating cold-adapted denitrifiers helps SAD to achieve high TN removal at psychrophilic temperatures and thus, is important for future applications in practical TN pollution control in urbanized streams.


Assuntos
Desnitrificação , Esgotos , Reatores Biológicos , Nitratos , Nitrogênio , Rios , Enxofre , Temperatura
20.
Sci Total Environ ; 726: 137948, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32481215

RESUMO

Vegetation phenology such as the start (SOS) and end (EOS) of the growing season, physiology (represented by seasonal maximum capacity of carbon uptake, GPPmax), and gross primary production (GPP) are sensitive indicators for monitoring ecosystem response to environmental change. However, uncertainty and disagreement between models limit the use phenology metrics and GPP derived from remote sensing data. Statistical models for estimating phenology and physiology were constructed based on key predictor variables derived from enhanced vegetation index (EVI) and land surface temperature (LST) data. Then, a statistical model that integrated remote sensing-based phenology and physiology (RS-SMIPP) data was constructed to estimate seasonal and annual GPP. These models were calibrated and validated with GPP observations from 512 site-years of FLUXNET data covering four plant functional types (PFTs) in the northern hemisphere: deciduous broadleaf forest, evergreen needle-leaf forest, mixed forest, and grassland. Our results showed that phenology and physiology were accurately estimated with relative root mean squared error (RMSEr) <20%, and the errors varied among the PFTs. Spring EVI was an important factor in explaining variation of GPPmax. The RS-SMIPP model outperformed the MOD17 algorithm in accurately estimating seasonal and annual GPP and reduced RMSEr from 25.34%-43.44% to 9.53%-26.19% for annual GPP of the different PFTs. These findings demonstrate that remote sensing-based phenological and physiological indicators could be used to explain the variations of seasonal and annual GPP, and provide an efficient way for improving GPP estimations at a global scale.


Assuntos
Ecossistema , Florestas , Plantas , Estações do Ano , Temperatura
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