{"results":[{"id":"ss_73bcf82127fc87dd8db7dafc3de241f7e81aab2f","title":"The Role of Soil pH in Plant Nutrition and Soil Remediation","authors":[{"name":"D. Neina"}],"abstract":"In the natural environment, soil pH has an enormous influence on soil biogeochemical processes. Soil pH is, therefore, described as the “master soil variable” that influences myriads of soil biological, chemical, and physical properties and processes that affect plant growth and biomass yield. This paper discusses how soil pH affects processes that are interlinked with the biological, geological, and chemical aspects of the soil environment as well as how these processes, through anthropogenic interventions, induce changes in soil pH. Unlike traditional discussions on the various causes of soil pH, particularly soil acidification, this paper focuses on relationships and effects as far as soil biogeochemistry is concerned. Firstly, the effects of soil pH on substance availability, mobility, and soil biological processes are discussed followed by the biogenic regulation of soil pH. It is concluded that soil pH can broadly be applied in two broad areas, i.e., nutrient cycling and plant nutrition and soil remediation (bioremediation and physicochemical remediation).","source":"Semantic Scholar","year":2019,"language":"en","subjects":["Environmental Science"],"doi":"10.1155/2019/5794869","url":"https://www.semanticscholar.org/paper/73bcf82127fc87dd8db7dafc3de241f7e81aab2f","pdf_url":"https://downloads.hindawi.com/journals/aess/2019/5794869.pdf","is_open_access":true,"citations":1090,"published_at":"","score":93},{"id":"ss_f9b2d921d795098e1a9171b233b9ff8d01aacbe4","title":"A Critical Review on Soil Chemical Processes that Control How Soil pH Affects Phosphorus Availability to Plants","authors":[{"name":"C. Penn"},{"name":"J. Camberato"}],"abstract":"Occasionally, the classic understanding of the effect of pH on P uptake from soils is questioned through the claim that maximum P uptake occurs at a pH much lower than 6.5–7. The purpose of this paper was to thoroughly examine that claim and provide a critical review on soil processes that control how soil pH affects P solubility and availability. We discuss how individual P retention mechanisms are affected by pH in isolation and when combined in soils, and how both real and apparent exceptions to the classic view can occasionally occur due to dynamics between mechanisms, experimental techniques (equilibration time, method of soluble P extraction, and pH adjustment), and plant species that thrive under acidic conditions. While real exceptions to the rule of thumb of maximum P availability at near neutral pH can occur, we conclude that the classic textbook recommendation is generally sound.","source":"Semantic Scholar","year":2019,"language":"en","subjects":["Chemistry"],"doi":"10.3390/AGRICULTURE9060120","url":"https://www.semanticscholar.org/paper/f9b2d921d795098e1a9171b233b9ff8d01aacbe4","pdf_url":"https://www.mdpi.com/2077-0472/9/6/120/pdf?version=1559979237","is_open_access":true,"citations":753,"published_at":"","score":85.59},{"id":"ss_4555d241f7f7a5b7b73ed100f7cfb70bc7d58105","title":"Preparation and application of pH-responsive drug delivery systems.","authors":[{"name":"Haitao Ding"},{"name":"Ping Tan"},{"name":"Shiqin Fu"},{"name":"Xiaohe Tian"},{"name":"Hu Zhang"},{"name":"Xuelei Ma"},{"name":"Zhongwei Gu"},{"name":"Kui Luo"}],"abstract":"Microenvironment-responsive drug delivery systems (DDSs) can achieve targeted drug delivery, reduce drug side effects and improve drug efficacies. Among them, pH-responsive DDSs have gained popularity since the pH in the diseased tissues such as cancer, bacterial infection and inflammation differs from a physiological pH of 7.4 and this difference could be harnessed for DDSs to release encapsulated drugs specifically to these diseased tissues. A variety of synthetic approaches have been developed to prepare pH-sensitive DDSs, including introduction of a variety of pH-sensitive chemical bonds or protonated/deprotonated chemical groups. A myriad of nano DDSs have been explored to be pH-responsive, including liposomes, micelles, hydrogels, dendritic macromolecules and organic-inorganic hybrid nanoparticles, and micron level microspheres. The prodrugs from drug-loaded pH-sensitive nano DDSs have been applied in research on anticancer therapy and diagnosis of cancer, inflammation, antibacterial infection, and neurological diseases. We have systematically summarized synthesis strategies of pH-stimulating DDSs, illustrated commonly used and recently developed nanocarriers for these DDSs and covered their potential in different biomedical applications, which may spark new ideas for the development and application of pH-sensitive nano DDSs.","source":"Semantic Scholar","year":2022,"language":"en","subjects":["Medicine"],"doi":"10.1016/j.jconrel.2022.05.056","url":"https://www.semanticscholar.org/paper/4555d241f7f7a5b7b73ed100f7cfb70bc7d58105","is_open_access":true,"citations":448,"published_at":"","score":79.44},{"id":"ss_f042b50222e901dec8190d8d90c7619dfd3986ed","title":"The soil pH and heavy metals revealed their impact on soil microbial community.","authors":[{"name":"Misbah Naz"},{"name":"Z. Dai"},{"name":"Sajid T. Hussain"},{"name":"M. Tariq"},{"name":"Subhan Danish"},{"name":"I. Khan"},{"name":"S. Qi"},{"name":"D. Du"}],"abstract":"Soil microbial community is the main indicator having a crucial role in the remediation of polluted soils. These microbes can alter soil pH, organic matter in soils (SOM), soil physic-chemical properties, and potential soil respiration rate via their enzymatic activities. Similarly, heavy metals also have a crucial role in soil enzymatic activities. For this purpose, a number of methods are studied to evaluate the impact of soil pH (a key factor in the formation of biogeographic microbial patterns in bacteria) on bacterial diversity. The effects of pH on microbial activity are glamorous but still unclear. Whereas, some studies also indicate that soil pH alone is not the single key player in the diversity of soil bacteria. Ecological stability is achieved in a pollution-free environment and pH value. The pH factor has a significant impact on the dynamics of microbes' communities. Here, we try to discuss factors that directly or indirectly affect soil pH and the impact of pH on microbial activity. It is also discussed the environmental factors that contribute to establishing a specific bacterial community structure that must be determined. From this, it can be concluded that the environmental impact on soil pH, reducing soil pH and interaction with this factor, and reducing the effect of soil pH on soil microbial community.","source":"Semantic Scholar","year":2022,"language":"en","subjects":["Medicine"],"doi":"10.1016/j.jenvman.2022.115770","url":"https://www.semanticscholar.org/paper/f042b50222e901dec8190d8d90c7619dfd3986ed","is_open_access":true,"citations":375,"published_at":"","score":77.25},{"id":"ss_f91120836a1f3187459d4280d9d62d15f6e7956b","title":"The effects of pH on nutrient availability depend on both soils and plants","authors":[{"name":"N. Barrow"},{"name":"A. Hartemink"}],"abstract":"The effects of pH on nutrient availability are not solely caused by to the effects on reaction with soils but are an interaction between these effects and the effects on rate of uptake by plants. Some effects are specific to particular ions, but an important aspect is that plant roots and soil particles both have variable charge surfaces. This influences availability, but in opposite directions. Sulfate is an example of this interplay. Its sorption by soil decreases markedly with increasing pH and thus “soil availability” increases. However, plant uptake also decreases with increasing pH thus “plant availability” decreases. For phosphate, the plant effect is stronger than the soil effect and uptake decreases with increasing pH. In contrast, effects of increasing pH on molybdate adsorption are so large that they dominate the overall effect. Sorption of cations, such as zinc or copper, increases with increasing pH but uptake rate also increases. The net effect is a small decrease in availability with increasing pH. Boron is an exception; there are small effects of pH on sorption; and it is the uncharged boric acid molecules that are taken up by plant roots. Their uptake is not affected by charge and uptake is proportional to the concentration of uncharged boric acid molecules. We argue that emphasis on the effects of pH on reactions with soil has led to a distorted picture of the effects of pH on nutrient availability.","source":"Semantic Scholar","year":2023,"language":"en","subjects":null,"doi":"10.1007/s11104-023-05960-5","url":"https://www.semanticscholar.org/paper/f91120836a1f3187459d4280d9d62d15f6e7956b","pdf_url":"https://link.springer.com/content/pdf/10.1007/s11104-023-05960-5.pdf","is_open_access":true,"citations":297,"published_at":"","score":75.91},{"id":"ss_2e5a9ab9ebfa7203251a94ccc0de0aa3e476895a","title":"Soil organic matter priming: The pH effects","authors":[{"name":"Chaoqun Wang"},{"name":"Y. Kuzyakov"}],"abstract":"Priming of soil organic matter (SOM) decomposition by microorganisms is a key phenomenon of global carbon (C) cycling. Soil pH is a main factor defining priming effects (PEs) because it (i) controls microbial community composition and activities, including enzyme activities, (ii) defines SOM stabilization and destabilization mechanisms, and (iii) regulates intensities of many biogeochemical processes. In this critical review, we focus on prerequisites and mechanisms of PE depending on pH and assess the global change consequences for PE. The highest PEs were common in soils with pH between 5.5 and 7.5, whereas low molecular weight organic compounds triggered PE mainly in slightly acidic soils. Positive PEs up to 20 times of SOM decomposition before C input were common at pH around 6.5. Negative PEs were common at soil pH below 4.5 or above 7 reflecting a suboptimal environment for microorganisms and specific SOM stabilization mechanisms at low and high pH. Short‐term soil acidification (in rhizosphere, after fertilizer application) affects PE by: mineral‐SOM complexation, SOM oxidation by iron reduction, enzymatic depolymerization, and pH‐dependent changes in nutrient availability. Biological processes of microbial metabolism shift over the short‐term, whereas long‐term microbial community adaptations to slow acidification are common. The nitrogen fertilization induced soil acidification and land use intensification strongly decrease pH and thus boost the PE. Concluding, soil pH is one of the strongest but up to now disregarded factors of PE, defining SOM decomposition through short‐term metabolic adaptation of microbial groups and long‐term shift of microbial communities.","source":"Semantic Scholar","year":2024,"language":"en","subjects":["Medicine"],"doi":"10.1111/gcb.17349","url":"https://www.semanticscholar.org/paper/2e5a9ab9ebfa7203251a94ccc0de0aa3e476895a","is_open_access":true,"citations":232,"published_at":"","score":74.96000000000001},{"id":"ss_3e36cca127d3a6144e5d8692fe4b772abc12314b","title":"Changes in soil pH and mobility of heavy metals in contaminated soils","authors":[{"name":"Alicja Kicińska"},{"name":"R. Pomykała"},{"name":"M. Izquierdo"}],"abstract":"In the present paper, the authors attempt to explain the importance of pH in soil environment studies and show what mistakes to avoid when measuring pH and interpreting the results obtained. The tests conducted (i.e., extraction in aqua regia, buffer capacity determination, and the impact of acidification on the amount of heavy metals extracted from soils) demonstrated how soil pollution and buffer capacity affect the pace of extracting cadmium (Cd), lead (Pb) and zinc (Zn) cations from heavily polluted and unpolluted soils following gradual acidification. It was shown that soil acidification caused a significant increase in metal mobility in the following order Cd \u003e Zn \u003e Pb and that the highest decrease in pH was observed after adding the first portion of acid. Further addition of acid caused a gradually lower decrease in pH. Soils from the polluted area presented a high buffer capacity. The control samples displayed a distinctly poorer resistance to pH changes in the soil environment. Special focus was placed on cadmium due to its high mobility in soils, even with neutral and slightly alkaline pH. The analyses revealed that in areas heavily polluted by long‐term industrial activity (Igeo \u003e 5 for Zn, Pb and Cd), it is very important to conduct extensive geochemical studies related to the presence and circulation of particularly toxic elements. This is because every environmental factor, especially pH, may significantly affect their mobility, causing metal ions to become more or less active or increasing or decreasing environmental risk related to their presence.","source":"Semantic Scholar","year":2021,"language":"en","subjects":null,"doi":"10.1111/ejss.13203","url":"https://www.semanticscholar.org/paper/3e36cca127d3a6144e5d8692fe4b772abc12314b","is_open_access":true,"citations":317,"published_at":"","score":74.50999999999999},{"id":"ss_51a39e2e59c49b8dbf03d02a00f1594f2806770f","title":"pH‐responsive polymers for drug delivery: Trends and opportunities","authors":[{"name":"J. Singh"},{"name":"P. Nayak"}],"abstract":"Polymer science has applications in biomedical engineering, prosthetics, surgical implants, and prospective pharmaceutical excipients for drug delivery. “Intelligent or Smart Polymers” are created for drug targeting either by derivatization of natural polymers or controlled radical polymerization of electrolytes. Their mode of action is governed by the environmental stimuli viz. temperature, pH, ionic concentration, magnetism, and so on. pH‐responsive polymers, because of their self‐assembling behavior, alter their solubility, conformation, surface activity, and hydrophilicity when exposed to a specific pH. The physiological pH varies from acidic nuclei to alkaline cytoplasm and highly acidic gastric juice to slightly alkaline plasma; thus, various polymers are under study for delivering small molecules, genes, peptides, enzymes, growth factors, and antibodies. The non‐invasive drug delivery routes like oral, ocular, nasal, pulmonary, transdermal, and rectal routes can be explored for targeting recombinant proteins, monoclonal antibodies, and small molecules with particular emphasis on the individual's physiological and pathological state. Further, these polymers can be designed into various architectures like dendrimers, liposomes, micelles, and metallic nanoparticles that can serve as drug reservoirs for sustaining drug release. The challenges in this field are the selection of biocompatible polymers with ease of synthesis and scale‐up, ensuring effective drug‐loading, and stability aspects, producing robust pharmacological data, and timely regulatory approvals. This review exclusively explores the physicochemical characteristics of pH‐responsive polymers, their categorization, various architectural entities, recent studies and patents, and their emerging applications concerning specific diseases.","source":"Semantic Scholar","year":2023,"language":"en","subjects":null,"doi":"10.1002/pol.20230403","url":"https://www.semanticscholar.org/paper/51a39e2e59c49b8dbf03d02a00f1594f2806770f","pdf_url":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/pol.20230403","is_open_access":true,"citations":195,"published_at":"","score":72.85},{"id":"ss_5610064871419211125b6621a50f708f69d28edc","title":"pH-Responsive Polymer Nanomaterials for Tumor Therapy","authors":[{"name":"Shunli Chu"},{"name":"Xiaolu Shi"},{"name":"Ye Tian"},{"name":"Fengxiang Gao"}],"abstract":"The complexity of the tumor microenvironment presents significant challenges to cancer therapy, while providing opportunities for targeted drug delivery. Using characteristic signals of the tumor microenvironment, various stimuli-responsive drug delivery systems can be constructed for targeted drug delivery to tumor sites. Among these, the pH is frequently utilized, owing to the pH of the tumor microenvironment being lower than that of blood and healthy tissues. pH-responsive polymer carriers can improve the efficiency of drug delivery in vivo, allow targeted drug delivery, and reduce adverse drug reactions, enabling multifunctional and personalized treatment. pH-responsive polymers have gained increasing interest due to their advantageous properties and potential for applicability in tumor therapy. In this review, recent advances in, and common applications of, pH-responsive polymer nanomaterials for drug delivery in cancer therapy are summarized, with a focus on the different types of pH-responsive polymers. Moreover, the challenges and future applications in this field are prospected.","source":"Semantic Scholar","year":2022,"language":"en","subjects":["Medicine"],"doi":"10.3389/fonc.2022.855019","url":"https://www.semanticscholar.org/paper/5610064871419211125b6621a50f708f69d28edc","pdf_url":"https://www.frontiersin.org/articles/10.3389/fonc.2022.855019/pdf","is_open_access":true,"citations":192,"published_at":"","score":71.75999999999999},{"id":"ss_d8050558e0df54154e34add72854af3443872789","title":"Soil pH - nutrient relationships: the diagram","authors":[{"name":"A. Hartemink"},{"name":"N. Barrow"}],"abstract":"","source":"Semantic Scholar","year":2023,"language":"en","subjects":null,"doi":"10.1007/s11104-022-05861-z","url":"https://www.semanticscholar.org/paper/d8050558e0df54154e34add72854af3443872789","is_open_access":true,"citations":152,"published_at":"","score":71.56},{"id":"ss_89a64d98bd789156bbaeea6bd73bdeaff0eccbd0","title":"pH-Responsive Nanocarriers in Cancer Therapy","authors":[{"name":"Nour Alsawaftah"},{"name":"Nahid S Awad"},{"name":"W. Pitt"},{"name":"G. Husseini"}],"abstract":"A number of promising nano-sized particles (nanoparticles) have been developed to conquer the limitations of conventional chemotherapy. One of the most promising methods is stimuli-responsive nanoparticles because they enable the safe delivery of the drugs while controlling their release at the tumor sites. Different intrinsic and extrinsic stimuli can be used to trigger drug release such as temperature, redox, ultrasound, magnetic field, and pH. The intracellular pH of solid tumors is maintained below the extracellular pH. Thus, pH-sensitive nanoparticles are highly efficient in delivering drugs to tumors compared to conventional nanoparticles. This review provides a survey of the different strategies used to develop pH-sensitive nanoparticles used in cancer therapy.","source":"Semantic Scholar","year":2022,"language":"en","subjects":["Medicine"],"doi":"10.3390/polym14050936","url":"https://www.semanticscholar.org/paper/89a64d98bd789156bbaeea6bd73bdeaff0eccbd0","pdf_url":"https://www.mdpi.com/2073-4360/14/5/936/pdf?version=1646042197","is_open_access":true,"citations":179,"published_at":"","score":71.37},{"id":"ss_dd3f4dc2413197d4917eddb18431875a108af251","title":"Intestinal and fecal pH in human health","authors":[{"name":"R. Yamamura"},{"name":"Kumi Y. Inoue"},{"name":"K. Nishino"},{"name":"S. Yamasaki"}],"abstract":"Gut microbiota has been reported to be closely related to host energy metabolism and immunity, and thus influence the development and progression of various human diseases. To date, the gut microbial metabolites such as short-chain fatty acids, defensins, cathelicidins, and lactoferrin in feces have been investigated as biomarkers associated with various disease conditions. In this review, we introduce intestinal and fecal pH, which is relatively easy and rapid to measure compared to the composition of the gut microbiota and its metabolites. In particular, this review presents the distribution of pH in the human body, its role and clinical significance, and various factors that affect intestinal and fecal pH, including the gut microbiota and its metabolites.","source":"Semantic Scholar","year":2023,"language":"en","subjects":["Medicine"],"doi":"10.3389/frmbi.2023.1192316","url":"https://www.semanticscholar.org/paper/dd3f4dc2413197d4917eddb18431875a108af251","pdf_url":"https://www.frontiersin.org/articles/10.3389/frmbi.2023.1192316/pdf?isPublishedV2=False","is_open_access":true,"citations":126,"published_at":"","score":70.78},{"id":"arxiv_2511.12353","title":"AstroMLab 5: Structured Summaries and Concept Extraction for 400,000 Astrophysics Papers","authors":[{"name":"Yuan-Sen Ting"},{"name":"Alberto Accomazzi"},{"name":"Tirthankar Ghosal"},{"name":"Tuan Dung Nguyen"},{"name":"Rui Pan"},{"name":"Zechang Sun"},{"name":"Tijmen de Haan"}],"abstract":"We present a dataset of 408,590 astrophysics papers from arXiv (astro-ph), spanning 1992 through July 2025. Each paper has been processed through a multi-stage pipeline to produce: (1) structured summaries organized into six semantic sections (Background, Motivation, Methodology, Results, Interpretation, Implication), and (2) concept extraction yielding 9,999 unique concepts with detailed descriptions. The dataset contains 3.8 million paper-concept associations and includes semantic embeddings for all concepts. Comparison with traditional ADS keywords reveals that the concepts provide denser coverage and more uniform distribution, while analysis of embedding space structure demonstrates that concepts are semantically dispersed within papers-enabling discovery through multiple diverse entry points. Concept vocabulary and embeddings are publicly released at https://github.com/tingyuansen/astro-ph_knowledge_graph.","source":"arXiv","year":2025,"language":"en","subjects":["astro-ph.IM","physics.soc-ph"],"url":"https://arxiv.org/abs/2511.12353","pdf_url":"https://arxiv.org/pdf/2511.12353","is_open_access":true,"published_at":"2025-11-15T20:47:03Z","score":69},{"id":"ss_7521fdd5521e8be04054b0e67c288fafe0db05a5","title":"Aerosol pH and its driving factors in Beijing","authors":[{"name":"Jing Ding"},{"name":"P. Zhao"},{"name":"Jie Su"},{"name":"Qun Dong"},{"name":"Xiang Du"},{"name":"Yufen Zhang"}],"abstract":"Abstract. Aerosol acidity plays a key role in secondary aerosol formation. The high-temporal-resolution PM2.5 pH and size-resolved aerosol pH in Beijing were calculated with ISORROPIA II. In 2016–2017, the mean PM2.5 pH (at relative humidity (RH) \u003e 30 %) over four seasons was 4.5±0.7 (winter) \u003e 4.4±1.2 (spring) \u003e 4.3±0.8 (autumn) \u003e 3.8±1.2 (summer), showing moderate acidity. In coarse-mode aerosols, Ca2+ played an important role in aerosol pH. Under heavily polluted conditions, more secondary ions accumulated in the coarse mode, leading to the acidity of the coarse-mode aerosols shifting from neutral to weakly acidic. Sensitivity tests also demonstrated the significant contribution of crustal ions to PM2.5 pH. In the North China Plain (NCP), the common driving factors affecting PM2.5 pH variation in all four seasons were SO42-, TNH3 (total ammonium (gas + aerosol)), and temperature, while unique factors were Ca2+ in spring and RH in summer. The decreasing SO42- and increasing NO3- mass fractions in PM2.5 as well as excessive NH3 in the atmosphere in the NCP in recent years are the reasons why aerosol acidity in China is lower than that in Europe and the United States. The nonlinear relationship between PM2.5 pH and TNH3 indicated that although NH3 in the NCP was abundant, the PM2.5 pH was still acidic because of the thermodynamic equilibrium between NH4+ and NH3. To reduce nitrate by controlling ammonia, the amount of ammonia must be greatly reduced below excessive quantities.","source":"Semantic Scholar","year":2019,"language":"en","subjects":["Chemistry"],"doi":"10.5194/ACP-19-7939-2019","url":"https://www.semanticscholar.org/paper/7521fdd5521e8be04054b0e67c288fafe0db05a5","pdf_url":"https://acp.copernicus.org/articles/19/7939/2019/acp-19-7939-2019.pdf","is_open_access":true,"citations":187,"published_at":"","score":68.61},{"id":"arxiv_2410.09067","title":"Evaluating Cooling Center Coverage Using Persistent Homology of a Filtered Witness Complex","authors":[{"name":"Erin O'Neil"},{"name":"Sarah Tymochko"}],"abstract":"In light of the increase in frequency of extreme heat events, there is a critical need to develop tools to identify geographic locations that are at risk of heat-related mortality. This paper aims to identify locations by assessing holes in cooling-center coverage using persistent homology (PH), a method from topological data analysis (TDA). Persistent homology has shown promising results in identifying holes in coverage of specific resources. We adapt these methods using a witness complex construction to study the coverage of cooling centers. We test our approach on four locations (central Boston, MA; central Austin, TX; Portland, OR; and Miami, FL) and use death times, a measurement of the size and scale of the gap in coverage, to identify most at risk regions. For comparison, we implement a standard technique for studying the risk of heat-related mortality called a heat vulnerability index (HVI). The HVI is a numerical score calculated for a geographic area based on demographic information. PH and the HVI identify different locations as vulnerable, thus indicating a potential value of assessing vulnerability from multiple perspectives. By using the regions identified by both persistent homology and the HVI, we provide a more holistic understanding of coverage.","source":"arXiv","year":2024,"language":"en","subjects":["stat.AP","cs.CG","physics.soc-ph"],"url":"https://arxiv.org/abs/2410.09067","pdf_url":"https://arxiv.org/pdf/2410.09067","is_open_access":true,"published_at":"2024-09-30T18:22:54Z","score":68},{"id":"arxiv_2402.09628","title":"History of Lattice Field Theory from a Statistical Perspective","authors":[{"name":"Wolfgang Bietenholz"}],"abstract":"Researchers working in lattice field theory constitute an established community since the early 1990s, and around the same time the online open-access e-print repository arXiv was created. The fact that this field has a specific arXiv section, hep-lat, which is comprehensively used, provides a unique opportunity for a statistical study of its evolution over the last three decades. We present data for the number of entries, $E$, published papers, $P$, and citations, $C$, in total and separated by nations. We compare them to six other arXiv sections (hep-ph, hep-th, gr-qc, nucl-th, quant-ph, cond-mat) and to two socio-economic indices of the nations involved: the Gross Domestic Product (GDP) and the Education Index (EI). We present rankings, which are based either on the Hirsch Index H, or on the linear combination $Σ= E + P + 0.05 C$. We consider both extensive and intensive national statistics, i.e. absolute and relative to the population or to the GDP.","source":"arXiv","year":2024,"language":"en","subjects":["hep-lat","physics.hist-ph","physics.soc-ph"],"url":"https://arxiv.org/abs/2402.09628","pdf_url":"https://arxiv.org/pdf/2402.09628","is_open_access":true,"published_at":"2024-02-15T00:03:42Z","score":68},{"id":"arxiv_2303.08101","title":"Impact of Covid-19 Pandemic on Water Pollution in Indian Rivers -- A Case Study","authors":[{"name":"Amardeepak Mahadikar"},{"name":"Krishna Anand"},{"name":"Chandra S. Reddy"}],"abstract":"Some of the important critical parameters for assessing the water quality like pH (Hydrogen ion concentration), DO (Dissolved Oxygen), BOD (Biological Oxygen Demand), etc., were monitored at different locations in some major Indian rivers. The results obtained from the study reveals that the critical parameters had increasing values in some monitoring locations, decreasing values, and no variation in values at some other places. It is recommended to have a pH value above 7, higher values of DO, lower values of BOD \u0026 FCC (Faecal Coliform Content) for improved water quality. Overall, the water quality improved in most Indian rivers. There was no discharge of industrial wastes, hotels/restaurants wastes, immersing of idols during religious festivals, etc., to the rivers during the COVID-19 lockdown. Therefore, enforcement of strict regulations by the Government of India for disposal of wastes produced from industrial \u0026 domestic activities can significantly reduce the water pollution levels in the Indian rivers.","source":"arXiv","year":2023,"language":"en","subjects":["physics.soc-ph"],"doi":"10.18280/eesrj.090403","url":"https://arxiv.org/abs/2303.08101","pdf_url":"https://arxiv.org/pdf/2303.08101","is_open_access":true,"published_at":"2023-01-17T06:53:16Z","score":67},{"id":"arxiv_2211.06503","title":"Multi-scale description of pedestrian collective dynamics with port-Hamiltonian systems","authors":[{"name":"Antoine Tordeux"},{"name":"Claudia Totzeck"}],"abstract":"Port-Hamiltonian systems (PHS) theory is a recent but already well-established modelling approach for non-linear physical systems. Some studies have shown lately that PHS frameworks are relevant for modelling and control of swarm and multi-agent systems. We identify in this contribution a general class of microscopic force-based pedestrian models that can be formulated as a port-Hamiltonian system. The pedestrian PHS has linear structure and dissipation components. Non-linear effects come from isotropic pedestrian interactions. Simulation results on a torus with disordered initial states show that the port-Hamiltonian pedestrian model can exhibit different types of dynamics. They range from relaxed speed models with no interaction, dynamical billiards, or crystallization dynamics to realistic pedestrian collective behaviors, including lane and strip formation for counter and crossing flow. The port-Hamiltonian framework is a natural multiscale description of pedestrian dynamics as the Hamiltonian turns out to be a generic order parameter that allows us to identify specific behaviours of the dynamics from a macroscopic viewpoint. Particular cases even enable through energy balance to determine the Hamiltonian behavior without requiring the tedious computation of the microscopic dynamics. Using PHS theory, we systematically identify a critical threshold value for the Hamiltonian, which relies only on exogenous input and can be physically interpreted.","source":"arXiv","year":2022,"language":"en","subjects":["physics.soc-ph"],"url":"https://arxiv.org/abs/2211.06503","pdf_url":"https://arxiv.org/pdf/2211.06503","is_open_access":true,"published_at":"2022-11-11T22:38:07Z","score":66},{"id":"arxiv_2112.03403","title":"A portrait of the collaboration network in quantum information","authors":[{"name":"Samuraí Brito"},{"name":"Rute Oliveira"},{"name":"Raabe Oliveira"},{"name":"Rafael Chaves"}],"abstract":"From its inception at the beginning of the eighties, with milestone results and ideas such as quantum simulation, the no-cloning theorem, and quantum computers, quantum information has established itself over the next decades, being nowadays a fast-developing field at the interface between fundamental science and a variety of promising technologies. In this work we aim to offer a portrait of this dynamic field, analyzing the statistical properties of the network of collaborations among its researchers. Using the quant-ph section from the arXiv as our database, we draw several conclusions on its properties. In particular, we show that the quantum information network of collaborations displays the small-world property, is very aggregated and assortative, being also in line with Newman's findings as for the presence of hubs and the Lotka's law regarding the average number of publications per author.","source":"arXiv","year":2021,"language":"en","subjects":["physics.soc-ph","quant-ph"],"url":"https://arxiv.org/abs/2112.03403","pdf_url":"https://arxiv.org/pdf/2112.03403","is_open_access":true,"published_at":"2021-12-06T22:59:14Z","score":65},{"id":"arxiv_2107.09188","title":"Analysis of Spatial and Spatiotemporal Anomalies Using Persistent Homology: Case Studies with COVID-19 Data","authors":[{"name":"Abigail Hickok"},{"name":"Deanna Needell"},{"name":"Mason A. Porter"}],"abstract":"We develop a method for analyzing spatial and spatiotemporal anomalies in geospatial data using topological data analysis (TDA). To do this, we use persistent homology (PH), which allows one to algorithmically detect geometric voids in a data set and quantify the persistence of such voids. We construct an efficient filtered simplicial complex (FSC) such that the voids in our FSC are in one-to-one correspondence with the anomalies. Our approach goes beyond simply identifying anomalies; it also encodes information about the relationships between anomalies. We use vineyards, which one can interpret as time-varying persistence diagrams (which are an approach for visualizing PH), to track how the locations of the anomalies change with time. We conduct two case studies using spatially heterogeneous COVID-19 data. First, we examine vaccination rates in New York City by zip code at a single point in time. Second, we study a year-long data set of COVID-19 case rates in neighborhoods of the city of Los Angeles.","source":"arXiv","year":2021,"language":"en","subjects":["physics.soc-ph","cs.CG","math.AT","q-bio.PE"],"url":"https://arxiv.org/abs/2107.09188","pdf_url":"https://arxiv.org/pdf/2107.09188","is_open_access":true,"published_at":"2021-07-19T22:59:37Z","score":65}],"total":7226416,"page":1,"page_size":20,"sources":["DOAJ","CrossRef","Semantic Scholar","arXiv"],"query":"physics.soc-ph"}