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2021 ◽  
Author(s):  
Ying Zhou ◽  
Zhuolu Li ◽  
Yuan Chen ◽  
Wei Wei

Abstract The Chengdu-Chongqing Economic Circle is an important center for promoting economic growth in the western region. Clarifying the driving force and restrictive factors of the urbanization development in Chengdu-Chongqing area is conducive to the further development of the region. First, this study uses piecewise linear regression to determine the characteristics of resource consumption. Then use Moran index to test the spatial agglomeration relationship. Finally, combining the characteristics of resource utilization and spatial agglomeration effects in Chengdu-Chongqing area, 143 cities are classified. The results show that: (1) The Chengdu-Chongqing economic circle as a whole presents the characteristics of high resource utilization pressure and abundant resource content. (2) In areas with obvious agglomeration effects, most cities have less pressure on natural resources, lower resource levels, less investment in environmental protection, and higher levels of urbanization. (3) The pressure on the use of natural resources and the expropriation of environmental protection measures are matched with each other in areas with significant concentration. (4) With the development of cities, the characteristics of resource utilization in various regions will tend to be unified. Researching and exploring the characteristics of resource utilization in the Chengdu-Chongqing Economic Circle will help the government to formulate relevant policies to ensure the coordinated development of regional ecology and the city.


2021 ◽  
Vol 8 ◽  
Author(s):  
Kwabena A. Owusu ◽  
Micaela M. Kulesz ◽  
Agostino Merico

The sustainable use of common pool resources (CPRs) such as fisheries constitutes a major challenge for society. A large body of empirical studies conducted in discrete time indicates that resource users are able to prevent the ‘tragedy of the commons' under institutional arrangements that can promote cooperation. However, the variability exhibited by the human behaviour and the dynamic nature of renewable resources require continuous time experiments to fully explain the mechanisms underpinning the sustainable use of resources. We conducted CPR experiments in continuous time to investigate how the extraction behaviour of resource users changes in real-time in response to changes in resource availability under communication and no communication. We find that when communication is allowed, users adjust their extraction efforts based on knowledge of previous resource availability. In contrast, when communication is not allowed, users do not incorporate resource availability into their utility function. These results suggest that communication does not merely provide a forum for coordination but mediates a causal relationship between resource levels and extraction behaviour. Our findings may help the development of effective resource management policies.


2021 ◽  
Vol 12 ◽  
Author(s):  
Angela Landolfi ◽  
A. E. Friederike Prowe ◽  
Markus Pahlow ◽  
Christopher J. Somes ◽  
Chia-Te Chien ◽  
...  

The ability of marine diazotrophs to fix dinitrogen gas (N2) is one of the most influential yet enigmatic processes in the ocean. With their activity diazotrophs support biological production by fixing about 100–200 Tg N/year and turning otherwise unavailable dinitrogen into bioavailable nitrogen (N), an essential limiting nutrient. Despite their important role, the factors that control the distribution of diazotrophs and their ability to fix N2 are not fully elucidated. We discuss insights that can be gained from the emerging picture of a wide geographical distribution of marine diazotrophs and provide a critical assessment of environmental (bottom-up) versus trophic (top-down) controls. We expand a simplified theoretical framework to understand how top-down control affects competition for resources that determine ecological niches. Selective mortality, mediated by grazing or viral-lysis, on non-fixing phytoplankton is identified as a critical process that can broaden the ability of diazotrophs to compete for resources in top-down controlled systems and explain an expanded ecological niche for diazotrophs. Our simplified analysis predicts a larger importance of top-down control on competition patterns as resource levels increase. As grazing controls the faster growing phytoplankton, coexistence of the slower growing diazotrophs can be established. However, these predictions require corroboration by experimental and field data, together with the identification of specific traits of organisms and associated trade-offs related to selective top-down control. Elucidation of these factors could greatly improve our predictive capability for patterns and rates of marine N2 fixation. The susceptibility of this key biogeochemical process to future changes may not only be determined by changes in environmental conditions but also via changes in the ecological interactions.


Author(s):  
Katariina Koskinen ◽  
Reetta Penttinen ◽  
Anni-Maria Örmälä-Odegrip ◽  
Christian G. Giske ◽  
Tarmo Ketola ◽  
...  

Over the past few decades, extensively drug resistant (XDR) resistant Klebsiella pneumoniae has become a notable burden to healthcare all over the world. Especially carbapenemase-producing strains are problematic due to their capability to withstand even last resort antibiotics. Some sequence types (STs) of K. pneumoniae are significantly more prevalent in hospital settings in comparison to other equally resistant strains. This provokes the question whether or not there are phenotypic characteristics that may render certain K. pneumoniae more suitable for epidemic dispersal between patients, hospitals, and different environments. In this study, we selected seven epidemic and non-epidemic carbapenem resistant K. pneumoniae isolates for extensive systematic characterization for phenotypic and genotypic qualities in order to identify potential factors that precede or emerge from epidemic successfulness. Studied characteristics include growth rates and densities in different conditions (media, temperature, pH, resource levels), tolerance to alcohol and drought, inhibition between strains, ability to compensate pH, as well as various genomic features. Overall, there are clear differences between isolates, yet, only drought tolerance was found to notably associate with non-epidemic K. pneumoniae strains. We further report a preliminary study on the potential to control K. pneumoniae ST11 with an antimicrobial component produced by a non-epidemic K. pneumoniae. This component initially restricts bacterial growth, but stable resistance develops rapidly in vitro.


2020 ◽  
Author(s):  
Alberto Vera ◽  
Siddhartha Banerjee

We develop a new framework for designing online policies given access to an oracle providing statistical information about an off-line benchmark. Having access to such prediction oracles enables simple and natural Bayesian selection policies and raises the question as to how these policies perform in different settings. Our work makes two important contributions toward this question: First, we develop a general technique we call compensated coupling, which can be used to derive bounds on the expected regret (i.e., additive loss with respect to a benchmark) for any online policy and off-line benchmark. Second, using this technique, we show that a natural greedy policy, which we call the Bayes selector, has constant expected regret (i.e., independent of the number of arrivals and resource levels) for a large class of problems we refer to as “online allocation with finite types,” which includes widely studied online packing and online matching problems. Our results generalize and simplify several existing results for online packing and online matching and suggest a promising pathway for obtaining oracle-driven policies for other online decision-making settings. This paper was accepted by George Shanthikumar, big data analytics.


2020 ◽  
pp. 1412-1418
Author(s):  
Miriam Mutebi ◽  
Isaac Adewole ◽  
Jackson Orem ◽  
Kunuz Abdella ◽  
Olujimi Coker ◽  
...  

PURPOSE Standard treatment guidelines improve patient outcomes, including disease-specific survival, in cancer care. The African Cancer Coalition was formed in 2016 to harmonize cancer treatment guidelines for sub-Saharan Africa. METHODS The African Cancer Coalition collaborated with the National Comprehensive Cancer Network (NCCN) and the American Cancer Society to harmonize 46 cancer treatment guidelines for use in sub-Saharan Africa. Harmonization for each guideline was completed by a group of approximately 6-10 African cancer experts from a range of specialties and with representation across resource levels. Each working group was chaired by an African oncologist and included a member of the appropriate NCCN guidelines panel. Treatment recommendations from the parent guidelines were distinguished as options that are generally available and should be considered standard care in most of the region or as highly advanced options for which cost or other resources may limit widespread availability. Additional recommendations specific to sub-Saharan Africa were added. RESULTS The NCCN Harmonized Guidelines for sub-Saharan Africa, available for download on the NCCN website and mobile application, provide flexible recommendations appropriate for the range of resources seen in African cancer programs, from private comprehensive cancer centers to resource-constrained public hospitals. IBM (Armonk, NY) has developed a digital interface—the Cancer Guidelines Navigator—that allows oncologists to access the treatment recommendations for the first five guidelines through an interactive web-based application. CONCLUSION Harmonized guidelines that reflect the diversity of resource levels that characterize the current state of clinical care for cancer in Africa have the potential to fill a crucial gap in efforts to standardize and improve cancer care in Africa.


2020 ◽  
Author(s):  
Bhaskar Kumawat ◽  
Ramray Bhat

AbstractAsexually reproducing populations of single cells evolve through mutation, natural selection, and genetic drift to enhance their reproductive fitness. The environment provides the contexts that allow and regulate their fitness dynamics. In this work, we used Avida - a digital evolution framework - to uncover the effect of mutation rates, maximum size of the population, and the relative abundance of resources, on evolutionary outcomes in asexually reproducing populations of digital organisms. We observed that over extended simulations, the population evolved predominantly to one of several discrete fitness classes, each with distinct sequence motifs and/or phenotypes. For a low mutation rate, the organisms acquired either of four fitness values through an enhancement in the rate of genomic replication. Evolution at a relatively higher mutation rate presented a more complex picture. While the highest fitness values at a high mutation rate were achieved through enhanced genome replication rates, a suboptimal one was achieved through organisms sharing information relevant to metabolic tasks with each other. The information sharing capacity was vital to fitness acquisition and frequency of the genotype associated with it increased with greater resource levels and maximum population size. In addition, populations optimizing their fitness through such means exhibited a greater degree of genotypic heterogeneity and metabolic activity than those that improved replication rates. Our results reveal a minimal set of conditions for the emergence of interdependence within evolving populations with significant implications for biological systems in appropriate environmental contexts.


2020 ◽  
Vol 127 (1) ◽  
pp. 123-133
Author(s):  
Michael Opoku Adomako ◽  
Peter Alpert ◽  
Dao-Lin Du ◽  
Fei-Hai Yu

Abstract Background and Aims Clonal plants dominate many plant communities, especially in aquatic systems, and clonality appears to promote invasiveness and to affect how diversity changes in response to disturbance and resource availability. Understanding how the special physiological and morphological properties of clonal growth lead to these ecological effects depends upon studying the long-term consequences of clonal growth properties across vegetative generations, but this has rarely been done. This study aimed to show how a key clonal property, physiological integration between connected ramets within clones, affects the response of clones to disturbance and resources in an aquatic, invasive, dominant species across multiple generations. Methods Single, parental ramets of the floating stoloniferous plant Pistia stratiotes were grown for 3 weeks, during which they produced two or three generations of offspring; connections between new ramets were cut or left intact. Individual offspring were then used as parents in a second 3-week iteration that crossed fragmentation with previous fragmentation in the first iteration. A third iteration yielded eight treatment combinations, zero to three rounds of fragmentation at different times in the past. The experiment was run once at a high and once at a low level of nutrients. Results In each iteration, fragmentation increased biomass of the parental ramet, decreased biomass of the offspring and increased number of offspring. These effects persisted and compounded from one iteration to another, though more recent fragmentation had stronger effects, and were stronger at the low than at the high nutrient level. Fragmentation did not affect net accumulation of mass by groups after one iteration but increased it after two iterations at low nutrients, and after three iterations at both nutrient levels. Conclusions Both the positive and negative effects of fragmentation on clonal performance can compound and persist over time and can be stronger when resource levels are lower. Even when fragmentation has no short-term net effect on clonal performance, it can have a longer-term effect. In some cases, fragmentation may increase total accumulation of mass by a clone. The results provide the first demonstration of how physiological integration in clonal plants can affect fitness across generations and suggest that increased disturbance may promote invasion of introduced clonal species via effects on integration, perhaps especially at lower nutrient levels.


2020 ◽  
Author(s):  
Elco van Burg ◽  
Wijnanda van Burg-Verhage

Background The COVID-19 pandemic is creating significant challenges for healthcare infrastructure for countries of all development and resource levels. Low-and-middle resource countries face even larger challenges, as their resources are stretched and often insufficient under normal circumstances. A village in the Papuan highlands of Indonesia; small, isolated, accessed only by small plane or trekking has experienced an outbreak typical of COVID-19. Methodology/Principal Findings This description was compiled from patient care records by lay healthcare workers in M20 (a pseudonym) during and after an outbreak and from medical doctors responding to online requests for help. We assume that, for reasons given, the outbreak that has been described was COVID-19. The dense social structure of the village resulted in a rapid infection of 90-95% of the population. Physical distancing and isolation measures were used, but probably implemented suboptimal and too late, and their effect on the illness course was unclear. The relatively young population, with a majority of women, probably influenced the impact of the epidemic, resulting in only two deaths so far. Conclusions/Significance This outbreak pattern of suspected SARS-CoV-2 in a village in the highlands of Papua (Indonesia) presents a unique report of the infection of an entire village population over five weeks. The age distribution, common in Papuan highland villages may have reduced case fatality rate (CFR) in this context and that might be the case in similar remote areas since survival to old age is already very limited and CFR among younger people is lower.


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