The COVID-19 pandemic has rapidly modified Earth's social-ecological systems in many ways; here we study its impacts on human-nature interactions. We conducted an online survey focused on peoples' ...relationships with the non-human world during the pandemic and received valid responses from 3,204 adult residents of the state of Vermont (U.S.A.). We analyzed reported changes in outdoor activities and the values associated with human-nature relationships across geographic areas and demographic characteristics. We find that participation increased on average for some activities (foraging, gardening, hiking, jogging, photography and other art, relaxing alone, walking, and watching wildlife), and decreased for others (camping, relaxing with others). The values respondents ranked as more important during the pandemic factored into two groups, which we label as "Nurture and Recreation values" and "Inspiration and Nourishment values." Using multinomial logistic regression, we found that respondents' preferences for changes in activity engagement and value factors are statistically associated with some demographic characteristics, including geography, gender, income, and employment status during the pandemic. Our results suggest that nature may play an important role in coping during times of crisis, but that the specific interactions and associated values that people perceive as most important may vary between populations. Our findings emphasize for both emergency and natural resources planning the importance of understanding variation in how and why people interact with and benefit from nature during crises.
1. Despite widespread focus on interspecific variation in trait-based ecology, there is growing evidence that intraspecific trait variability can play a fundamental role in plant community responses ...to environmental change and community assembly. 2. Here, we quantify the strength and direction of inter- and intraspecific plant community trait responses along a 900 m elevation gradient spanning alpine and subalpine plant communities in southern New Zealand. We measured five commonly used leaf traits (i.e. dry matter content, N and P concentrations, leaf area and specific leaf area) on all 31 dominant and subordinate species recorded along the gradient, and examined their species-specific and community-level responses to elevation using both abundance-weighted and nonweighted averages of trait values. 3. By decomposing the variance of community-level measures of these traits across the gradient, we showed that the contribution of interspecific variation to the response of plant assemblages to elevation was stronger than that of intraspecific variation, for all traits except specific leaf area. Further, the relative contributions of interspecific effects were greater when abundance-weighted rather than nonweighted measures were used. We also observed contrasting intraspecific trait responses to the gradient among species (particularly for leaf N and P concentrations), and found both positive and negative covariation between inter- and intraspecific effects on community-level trait values. 4. The weak community-average trait responses to elevation, as found for specific leaf area (SLA) and leaf N and P concentrations, resulted from strong but opposing responses among vs. within species, which are not typically accounted for in species-based measures of plant community responses. For instance, increasing elevation (and associated factors such as a decrease in soil nutrient availability) favoured the dominance of species with relatively high leaf nutrient concentrations while simultaneously triggering an intraspecific decrease in the leaf nutrient concentrations of these species. 5. The context dependency of positive and negative covariation between inter- and intraspecific trait variability, and the species-specific nature of intraspecific shifts in functional trait values, reveal highly complex plastic responses of plants to environmental changes, and high-lights the need for greater consideration of the role that intraspecific variation plays in community-level processes.
We present a new measurement of the positive muon magnetic anomaly, a_{μ}≡(g_{μ}-2)/2, from the Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. We have analyzed more than 4 times ...the number of positrons from muon decay than in our previous result from 2018 data. The systematic error is reduced by more than a factor of 2 due to better running conditions, a more stable beam, and improved knowledge of the magnetic field weighted by the muon distribution, ωover ˜_{p}^{'}, and of the anomalous precession frequency corrected for beam dynamics effects, ω_{a}. From the ratio ω_{a}/ωover ˜_{p}^{'}, together with precisely determined external parameters, we determine a_{μ}=116 592 057(25)×10^{-11} (0.21 ppm). Combining this result with our previous result from the 2018 data, we obtain a_{μ}(FNAL)=116 592 055(24)×10^{-11} (0.20 ppm). The new experimental world average is a_{μ}(exp)=116 592 059(22)×10^{-11} (0.19 ppm), which represents a factor of 2 improvement in precision.
Acid volatile sulfide (AVS) Rickard, David; Morse, John W.
Marine chemistry,
12/2005, Letnik:
97, Številka:
3
Journal Article
Recenzirano
The sequestration of sulfur within sedimentary pyrite is a major sink in the global biogeochemical sulfur cycle and has consequent impacts on the related cycles of carbon and oxygen. In many ...sedimentary environments, a zone exists which releases H
2S if treated with acid. The materials that produce this sulfide are described as acid volatile sulfides or AVS and the sulfide which is evolved and collected by this treatment is called acid volatile sulfide (AVS-S). In this research review we show that AVS represents part of a complex and dynamic biogeochemical system which is not defined simply by the analysis of AVS-S.
During the 40 years since R.A. Berner first defined the concept of acid volatile sulfide, a number of scientific myths have developed regarding the nature and composition of AVS and its role in the global sulfur cycle. We show that:
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AVS is not equivalent to FeS and solid FeS phases have rarely been identified in marine sediments. AVS is a complex and variable component which does not represent any singular or simple group of sediment components.
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The commonly used extraction methods do not quantitatively extract AVS minerals (mackinawite and greigite) without also significantly releasing sulfide from pyrite.
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AVS varies geographically and AVS is not the same component or set of components wherever it is found.
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The solubilities of FeS and Fe
3S
4 in neutral to alkaline systems are presently poorly constrained and pore water saturation state calculations cannot be used to support the presence of specific AVS minerals.
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The colored zone in sediments does not reflect the distribution of AVS.
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AVS is not always a minor fraction of total reduced sulfide (TRS) which dominantly occurs near the sediment–water interface. AVS minerals are not required precursors for pyrite formation.
A better understanding of the sedimentary sulfur system, including its nature, formation and transformations, is a key component in understanding the evolution of the Earth and its future development. However, some basic parameters, such as the solubility and composition of the metastable iron sulfide solids, are still not constrained. Even the presence of these minerals in most sedimentary systems remains equivocal. Aqueous FeS clusters appear to be ubiquitous and appear to have significant geochemical and biological roles. The roles of organisms, especially in modifying rates and products, remain a key area of research.
Although AVS may have served its purpose in the earlier exploratory days of the study of sedimentary sulfides, the concept is now probably more of a hindrance than a help in advancing this field. It is reasonable to question if it is not time to simply do away with the AVS concept altogether and get on with the business of trying to deal more directly with the behavior of the more important components known to fall within the group of sulfide species that contribute to sulfide that is volatilized when acid is added to a sediment.
Among the most important set of chemical reactions occurring under near Earth surface conditions are those involved in the dissolution of sedimentary carbonate minerals. These minerals comprise about ...20% of Phanerozoic sedimentary rocks. Calcite and, to a significantly lesser extent, dolomite are the major carbonate minerals in sedimentary rocks. In modern sediments, aragonite and high-magnesian calcites dominate in shallow water environments. However, calcite is by far the most abundant carbonate mineral in deep sea sediments. An understanding of the factors that control their dissolution rates is important for modeling of geochemical cycles and the impact of fossil fuel CO
2 on climate, diagenesis of sediments and sedimentary rocks. It also has practical application for areas such as the behavior of carbonates in petroleum and natural gas reservoirs, and the preservation of buildings and monuments constructed from limestone and marble.
In this paper, we summarize important findings from the hundreds of papers constituting the large literature on this topic that has steadily evolved over the last half century. Our primary focus is the chemical kinetics controlling the rates of reaction between sedimentary carbonate minerals and solutions. We will not attempt to address the many applications of these results to such topics as mass transport of carbonate components in the subsurface or the accumulation of calcium carbonate in deep sea sediments. Such complex topics are clearly worthy of review papers on their own merits.
Calcite has been by far the most studied mineral over a wide range of conditions and solution compositions. In recent years, there has been a substantial shift in emphasis from measuring changes in solution composition, to determine “batch” reaction rates, to the direct observation of processes occurring on mineral surfaces using techniques such as atomic force microscopy (AFM). However, there remain major challenges in integrating these two very different approaches. A general theory of surface dissolution mechanisms, currently lacking (although see Lasaga and Luttge Science 291 (2001) 2400), is required to satisfactorily relate observations of mineral surfaces and the concentration of dissolved components.
Studies of aragonite, high-magnesian calcites, magnesite, and dolomite dissolution kinetics are much more limited in number and scope than those for calcite, and provide, at best, a rather rudimentary understanding of how these minerals are likely to behave in natural systems. Although the influences of a limited number of reaction inhibitors have been studied, probably the greatest weakness in application of experimental results to natural systems is understanding the often profound influences of “foreign” ions and organic matter on the near-equilibrium dissolution kinetics of carbonate minerals.
A new highly sensitive method of looking for electric dipole moments of charged particles in storage rings is described. The major systematic errors inherent in the method are addressed and ways to ...minimize them are suggested. It seems possible to measure the muon EDM to levels that test speculative theories beyond the standard model.
Acute myeloid leukemia (AML) is the most common and deadly type of leukemia affecting adults. It is typically managed with rounds of non-targeted chemotherapy followed by hematopoietic stem cell ...transplants, but this is only possible in patients who can tolerate these harsh treatments and many are elderly and frail. With the identification of novel tumor-specific cell surface receptors, there is great conviction that targeted antibody therapies will soon become available for these patients.
In this review, we describe the current landscape of known target receptors for monospecific and bispecific antibody-based therapeutics for AML. Here, we characterize each of the receptors and targeted antibody-based therapeutics in development, illustrating the rational design behind each therapeutic compound. We then discuss the bispecific antibodies in development and how they improve immune surveillance of AML. For each therapeutic, we also summarize the available pre-clinical and clinical data, including data from discontinued trials.
One antibody-based therapeutic has already been approved for AML treatment, the CD33-targeting antibody-drug conjugate, gemtuzumab ozogamicin. Many more are currently in pre-clinical and clinical studies. These antibody-based therapeutics can perform tumor-specific, elaborate cytotoxic functions and there is growing confidence they will soon lead to personalized, safe AML treatment options that induce durable remissions.
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