An updated inventory of marine opisthobranch(Mollusca,Gastropoda)from the territorial waters of the Republic of Mauritius

Island ecosystems support diverse aquatic invertebrate communities comprising endemic taxa.Documentation of existing species is important for conservation.In this study,a checklist of marine opisthobranch from the Republic of Mauritius is presented.A combination of benthic surveys(50 m×5 m in triplicates),rover diving techniques and photo documentation were used over two years(2018–2020)within 35 sheltered and unsheltered lagoons.Morphological and molecular analysis were used for identification.Species composition within sheltered and unsheltered areas in Mauritius was estimated using the Bray-Curtis similarity.The checklist featured 117 species belonging to 61 genera and 28families,of which 13 are new records.The findings increased the knowledge of opisthobranch diversity from the Mauritius by 15.4%.Among the listed species,the distribution range of Cyerce nigra,Actinocyclus papillatus,and Phyllidia picta extended from the Western Pacific to the South Western Indian Ocean.Molecular analysis of the undescribed Gymnodoris sp.showed it resembled Gymnodoris sp.from Hawaii and were different by a genetic distance value of 10.6%.The species richness and evenness were higher within the sheltered regions of Mauritius which harboured the food resource of opisthobranch.These areas as compared to unsheltered regions were heavily populated,suggesting the probable influence of wave actions on opisthobranch diversity and abundance.The order Nudibranchia was reported as most speciose,with 86 species.The Sacoglossa and Nudibranchia were observed only on macroalgae and sponges respectively.High abundance was also recorded on shipwrecks which are the most common form of artificial reefs.With the inclusion of observations from previous studies,201species belonging to 94 genera and 36 families are now known from the Mauritius.

Contribution of Genomic Surveillance in the Detection and Monitoring of SARS-CoV-2 Variants during the 6 Pandemic Waves in the Central African Republic from 2020 to 2023

Objective: The COVID-19 pandemic has highlighted the need to strengthen diagnosis and genomic surveillance capacities. In 2021, Central African managed five waves of COVID-19 by integrating genomic surveillance into their health monitoring system. This study sought to report surveillance data from the National Laboratory of Clinical Biology and Public Health and describe the circulation of SARS-CoV-2 variants. Materials and Methods: This retrospective, descriptive observational study spans three years, from April 2020 to November 2023. It was conducted on a population of consenting volunteers from across the Central African Republic, who were tested using RT-PCR on nasopharyngeal samples. Data with sufficient information were obtained from the National Laboratory of Clinical Biology and Public Health (LNBCSP) databases. Sequencing was largely carried out at the National Institute of Biomedical Research (INRB) in Kinshasa until May 2023, and subsequently at the LNBCSP. Results and Discussion: Out of 97,864 RT-PCR tests performed, 9,764 were positive, resulting in a prevalence of 9.98%. The average age of the patients was 39.97 years ± 13.76, and the male-to-female sex ratio was 2.12. RT-PCR test positivity was significantly associated with age (p = 0.001), sex (p = 0.013) and clinical manifestations. Ten variants circulated during the five recorded waves, with Omicron (B.1.1.529), Delta (B.1.617.2) variants being predominant. Notably, the B.1.620 and B.640 variants were prominent during the second wave. Conclusion: This retrospective study provides key insights into the COVID-19 pandemic in the CAR. It identifies risk factors and details the circulation of various SARS-CoV-2 variants. Enhancing national genomic surveillance capacities would enable the country to better respond to future pandemic challenges.

Contribution to the Study of the Incidence of Post-Streptococcal Complications in Republic Central African Republic from 2015 to 2018

Introduction: Acute rheumatic fever (AAR) is a non-suppurative complication of late infection by group A. Infections due to streptococci remain a public health problem in the Central African Republic. The present study aims to determine the incidence rate of AAR cases and its complications. Methodology: This was a retrospective and analytical study over a period of 4 years (from January 2015 to December 2018) at the National Laboratory of Clinical Biology and Public Health (LNBCSP) in Bangui. It focused on samples concerning the diagnosis of AAR and patient files seen in consultation in the capital’s reference health establishments. Laboratory registers and patient consultation files were used to collect data. They were entered into Excel 2010 to be analyzed with Epi Info 7. A univariate analysis by logistic regression, Ficher’s exact test, and chi2 at the 5% threshold (p Results: We analyzed 94 cases meeting Jones’s criteria. The ages of the patients ranged from 18 to 85 years (mean age 52 years and mode 45 years). The incidence rate of AAR for the female sex was higher than that of the male sex during the study period (p > 0.05). It went from 166.6 in 2015 to 200 in 2016 and 2018 cases of AAR per 1000 people per year. The average incidence rate was 296.18 cases of AAR per 1000 people per year. The average incidence rate was 223.5 cases of AAR per 1000 people per year for joint damage. Joint damage represented 80.85% (RR = 0.62;Chi2 = 4.88;95% CI [0.39-0.97];p Conclusion: The study allowed data on the impact rate and complications of the AAR in Bangui. Special attention to data management will help produce a complete result on the problem. Joint complications predominated. Sustaining an effective surveillance system and preventing infection would help reduce the risk of AAR occurrence.

Historical review and reflections on the participation of acupuncture and moxibustion in the treatment of epidemics in the People’s Republic of China (from 1950 until now)

Since the establishment of the People’s Republic of China, both the Communist Party and the government have placed great emphasis on the advancement of traditional Chinese medicine. Acupuncture and moxibustion have been actively involved in combating major epidemics such as malaria, schistosomiasis, and COVID-19. This article conducts a historical review of these three significant cases to elucidate how the acupuncture community has effectively utilized its unique advantages and characteristics through theoretical discussions, clinical practices, experimental research, as well as receiving administrative leadership and political support from the Communist Party of China and government. We provide an objective evaluation of their effectiveness while summarizing historical experiences to serve as a reference for future utilization of acupuncture and moxibustion therapy in epidemic relief efforts. Additionally, propose four suggestions: strengthening Party leadership and enhancing political support;timely summarization of experiences to establish programs and systems;deepening scientific research by integrating experimental findings with clinical practice;focusing on public awareness campaigns and education to solidify grassroots foundations.

Antibiotic Resistance Profile of Salmonella Strains Isolated at the National Clinical Biology and Public Health Laboratory in Bangui, Central African Republic

In Africa, each year, there are estimated to be more than 91 million cases of salmonellosis and 137,000 cases of death. The problem of antibiotic resistance in Salmonella strains is a threat to public health. The objective of this study is to evaluate the antibiotic resistance profile of Salmonella strains isolated in biological products analyzed at the National Laboratory of Clinical Biology and Public Health (NLCBPH) in Bangui. This is, therefore, a cross-sectional study with a descriptive aim, running from January to December 2022. It focused on the strains of Salmonella isolated and identified in stools, urines, and blood samples. For each strain of Salmonella isolated, an antibiogram was carried out following the recommendations of the French Society of Microbiology (CASFM, 2022). A total of 93 strains of Salmonella have been recorded. The age group 0 - 9 years was 29% and that of >50 years was 11%. The median age of patients was 30 years with a minimum of 1 and a maximum of 78 years. The female gender was more represented at 52.69% than the male gender at 47.31%, i.e. a sex ratio of 0.89 (M/F). Salmonella strains were much more isolated in stools at 62% followed by urines at 29% and blood at 6%. Salmonella arizonae strains were more represented with 52%. Salmonella strains have a resistance rate to Tetracycline of 62.37% followed by Penicillins of 50%. The rate of multi-antibiotic resistance of the Salmonella strains isolated represented 48.38%. Salmonella spp. strains were multi-resistant at 58.69% followed by Salmonella arizonae strains at 47.91%. There is a significant association between the different families of antibiotics and Salmonella strains (p < 0.05). According to the results obtained, Penicillins, Phenicoles, and Cyclins had a high rate of resistance on Salmonella strains. No strain-producing Broad Spectrum Beta-lactamase has been isolated. Salmonella strains represent a zoonotic health danger, constitute a public health problem and remain a current subject. This germ is resistant to the antibiotics used. It is, therefore, essential to emphasize monitoring the resistance of these germs in the Central African Republic (CAR) to improve the health of the population.

Fatty Acid Composition of Hazelnut Kernel Oil from Coula edulis Collected in the Republic of Congo

Coula edulis is non-timber forest product (NTFP) used in Africa for its hazelnuts, which contain edible seeds with a demonstrated nutritional potential. However, there have been very few scientific studies of this species in the Republic of Congo. Thus, the aim of the current study was therefore to determine the fatty acid composition of the oil extracted from Coula edulis hazelnut seeds collected at random in the Republic of Congo. The oil was extracted using the Soxhlet method and its fatty acid composition was determined by gas chromatography. The extracted oil from Coula edulis hazelnut kernels is rich in monounsaturated fatty acids (95.28%), particularly oleic acid (94.5%), which classifies it as an oleic oil and gives it interesting nutritional and therapeutic properties. On the other hand, saturated fatty acids (4.15%) and polyunsaturated fatty acids (0.35%) are not well represented. Its low poly-unsaturated fatty acid content makes it more stable when stored at room temperature.

Contribution to the Study of Fungal Strains Contaminating Peanut Pastes in Bangui (Central African Republic)

Introduction: Peanut pastes are food products resulting from artisanal or industrial processing, used in cooking in Africa in general and in Central African Republic in particular. These peanut pastes are often contaminated by molds and filamentous fungi involved in the degradation of hygienic and organoleptic or even toxicological quality. This study aims to determine the epidemiological profile of molds contaminating peanut pastes sold on the Central African market. Methodology: This was a cross-sectional study carried out from June to September 2023. Samples of peanut pastes sold on Central African market were taken and analyzed at the National Laboratory of Clinical Biology and Public Health using the conventional microbiology method according to ISO 7954 standards. The data obtained were collected in the ODK 2023.3.1 application and analyzed with the Epi Info 7 software. A multivariate analysis by logistic regression, Ficher’s exact test, and chi2 at the 5% threshold (p Penicillium sp.;11.25% of Mucor sp.;10.63% of Aspergillus terrei;3.13% of Aspergillus niger;1.25% of Aspergillus medullans;28.13% of Aspergillus flavus;2.50% of Aspergillus fumigatus. Peanut pastes stored beyond three days were more contaminated (94.19%). Conclusion: The results of this study made it possible to highlight strains of mold that impact the hygienic and organoleptic quality of peanut pastes sold at the Central African market. Most of the isolated strains were the Aspergillus flavus species which is recognized by its toxigenic effects. This species is much more incriminated in the contamination of foodstuffs with the production of the toxin which causes underlying pulmonary pathologies in humans.

Investigating Non-Compliance with COVID-19 Vaccination through Hesitancy, Refusal, and Access Limitation: A Community-Based Survey from the Democratic Republic of the Congo

Introduction: Vaccination plays a pivotal role in mitigating the repercussions of the COVID-19 pandemic. However, vaccination campaigns encounter obstacles, especially in developing countries like the Democratic Republic of the Congo (DRC). This study aimed at investigating the roles of vaccine hesitancy, refusal, and access barriers, while identifying individual-level factors associated with non-vaccination in Mbujimayi, DRC. Methods: A community-based cross-sectional survey was conducted in three health districts and included 1496 residents. Attitudes and behaviors related to seeking COVID-19 vaccination were assessed using a standardized questionnaire. Hierarchical logistic regression modeling was used to assess factors potentially affecting non-compliance with vaccination. Results: Among participants (median age = 33, IQR = 23.3, M/F sex ratio = 0.7), 60% displayed misconceptions about COVID-19 or its vaccine, while only 35.2% perceived COVID-19 as a significant health threat. Vaccination coverage was estimated at 49.1% (95% CI: 47.5;52.6), with 71.8% of vaccinated individuals having received one dose. Among the unvaccinated individuals, 50.9% expressed no intention to be vaccinated in the future, citing hesitation (30.4%) or refusal (39.6%) mainly due to side effects or distrust of vaccines. Conversely, 32.7% of the unvaccinated persons expressed access barriers despite willingness to be vaccinated. Misconceptions about COVID-19 and its vaccines were the main drivers of vaccination non-compliance. Conclusion: These findings demonstrate significant vaccine non-compliance driven by hesitancy, refusal, and access barriers. Strategies to enhance vaccination coverage and pandemic preparedness should address misconceptions, sociodemographic barriers, and geographic disparities.

A Biogas Production Model from the Combination of Pig Manure and Cow Dung in N’Zérékoré City, Republic of Guine

This present research work focuses on the valorization of pig droppings for production of biogas in mono digestion and co-digestion with proportions of cow dung from the urban commune of N’Zérékoré. It was carried out in December 2020 in the Physics laboratory of the University of N’Zérékoré. The anaerobic digestion process took 25 days in an almost constant ambient temperature of 25˚C. Five digesters were loaded on 12/06/2020, two of which with 1 kg of pig dung and 1 kg of cow dung both in mono-digestion. The 3 other digesters in co-digestion with different proportions of pig manure and cow dung. The substrate in each digester is diluted in 2 liters of water, with a proportion of (1/2). The main results obtained are: 1) the evolution of the temperature and pH during digestion process, 2) the average biogas productions 0.61 liters for (D1);1.20 liter for (D2);1.65 liter for (D3);1.51 liter for (D4) and 1.31 liter for (D5). The cumulative amounts of biogas are respectively: D1 (7.95 liters), D2 (15.60 liters), D3 (21.50 liters), D4 (19.65 liters) and D5 (17.05 liters). The total cumulative production is 81.75 liters at the end of the process. The originality of this research work is that the proposed model examines the relation between the daily biogas production and the variation of temperature, pH and pressure. The combustibility test showed the biogas produced during the first week was no combustible (contains less than 50% methane). Combustion started from the biogas produced from the 15th day and it is from the 20th day that a significant amount of stable yellow/blue flame was observed. The results of this study show the combination of pig manure and cow dung presents advantages for optimal biogas production.

Coordination of Regulation Devices for Damping Power Oscillations in a Dynamic Disturbance Context: A Fuzzy Logic-Based Approach Applied to the Electrical Grid of the Republic of Congo

This article presents a fuzzy logic-based approach to coordinate the control devices of the power system, such as Power System Stabilizers (PSS) and Static Synchronous Compensators (STATCOM), to damp power oscillations caused by dynamic disturbances. At first, we used the Lyapunov method to study the dynamic stability of the power grid in the Republic of Congo. This method allowed us to analyze the eigenvalues of the state variable matrix and highlight the eigenvalues in the complex plane. Secondly, we proposed a fuzzy logic-based controller to account for uncertainties existing near the thresholds. The inputs to this controller are the generator speed and generator rotor angle. We demonstrated the effectiveness and feasibility of this fuzzy control by applying it to the power grid of the Republic of Congo, with three power stabilizers and two STATCOMs. .

Health Safety of the Fish from the Luapula River in Democratic Republic of Congo

The Luapula River has received mining discharges from Lubumbashi and Kipushi Gecamines for several decades and from the CHEMAF company since 2005. It also received mining waste from SODIMICO. The Luapula River has Lake Banguelo as its source in Zambia and flows into Lake Moero, which is located on the border between Zambia and the Democratic Republic of Congo. The objective of this study is to assess the health safety of the fish from the Luapula River. Fish samples were collected in August 2015 at the site of the locality of Kasenga located downstream of the mining activities (n = 14) and presumed to be polluted. On the other hand, reference fish samples were taken upstream of any mining activity of the Panda, Kasungwe and Congo Rivers at the sections located near their sources and presumed not to be polluted by mining wastes. (n = 11). Ten Metal Trace Elements (MTE) were assayed at the laboratory of the Congolese Control Office (OCC) of Lubumbashi and at the laboratory of the Catholic University of Leuven in Belgium using ICP-OES and ICP-MS. To assess and evaluate the health safety of fish from the Luapula River, the concentrations of fish samples from the Luapula River were compared with the concentrations of the reference fish samples from the Panda Kasungwe and Congo rivers by the Wilcoxon test. The concentrations of fish samples from the Congo River were also compared with the maximum acceptable metal trace element concentrations established by the FAO, WHO, EU (European Union) and other regulatory bodies. as reported by Akoto et al. The results of this study showed that the fish from the Luapula River is contaminated in Cd, Cu, Ni and Pb, and are not fit for human consumption. The results obtained will be brought to attention of the decision-makers of the Province of Haut-Katanga, so that measures can be taken to ban metallurgical factories to drump their mining wastes into waterways.

Leishmaniasis in the Argentine Republic: Temporal and geographical distribution from 2013 to 2017

Objective: To assess the temporal and geographical distribution of confirmed cases of cutaneous, mucocutaneous and visceral leishmaniasis in the Argentine Republic from 2013 to 2017. Methods: A retrospective study was carried out using data collected from the Integrated Surveillance Bulletin database of the National System of Health Surveillance. Confirmed cases of cutaneous, mucocutaneous and visceral leishmaniasis up to the 52 nd epidemiological week of each year was included. Results: In the 5 years period, 1 295 confirmed leishmaniasis cases were reported in the Argentine Republic. One thousand twenty-eight(1 028) cases corresponded to cutaneous leishmaniasis(87.10%), being the most common type of leishmaniasis. Mucocutaneous leishmaniasis was in the second place in the country with 115 cases reported, mostly in the Northwest and Northeast regions. A total of 52 individuals with visceral leishmaniasis were identified and Misiones Province was the most affected. Conclusions: It is important to analyze the temporal and geographical distribution of leishmaniasis in order to provide an adequate management and surveillance.

Mass Distribution Campaign of Long-Lasting Insecticidal Nets in the Democratic Republic of Congo from 2018 to 2021 in the Context of the Emergence of COVID-19: Results and Lessons Learned

Introduction: The DRC had planned 23 mass distribution campaigns distribution of long-lasting insecticidal nets (LLIN) for the years 2018-2020, the implementation of which spanned from 2018 to July 2021. This article reviews the campaign’s planning process, the results, challenges, and lessons learned. Methods: A descriptive method was used to postpone the planning and implementation process according to the National Malaria Control Program (NMCP) standards adapted to the COVID-19 context. The changes and adaptations implemented as well as the challenges encountered are described. Results: Between January 2018 to June 2021, 23 LLIN mass distribution campaigns were organized in the DRC with the financial support of The Global Fund to Fight against Tuberculosis, AIDS and Malaria (GFTAM) and Against Malaria Foundation (AMF) allowing the distribution of 55,273,473 LLINs to 19,048,372 households at risk of malaria transmission with an average of 2.9 LLINs per household. The enumerated population (111,081,191) exceeded 7% of the micro plans projected population (102,790,391) while the number of households enumerated (19,311,629) was 3% lower compared to the micro planning projection households (19,862,417). Compared to a reported household coverage of 96% of households achieved over the expected households, the independent monitoring carried out revealed 91% of households served in the intervention areas. The main reasons for not reaching households mentioned by the respondents were absence at the time of distribution (26%) followed by the loss of vouchers (16%). Several communication channels were used among which, community workers were the most frequently mentioned (63.1%), followed by radios (18.5%) and churches (12.4%). Conclusion: Good planning, effective coordination of stakeholders, and revision of the implementing campaigns methods following the COVID-19 were factors in the success of this campaign. An effort to respect the schedules for renewing LLINs in households, coupled with good continuous distribution, is necessary to maintain the gains and hope for an impact in terms of morbidity and mortality reduction of malaria.

Landscape Design of Parks Based on Red Tourism——With the Memorial Park of Soviet Republic of China in Ruijin,Jiangxi Province as a Study Case

Red tourism is a derivative product of organized patriotic education and revolutionary education activities.Memorial Park of Soviet Republic of China in Ruijin City,Jiangxi Province,as a representative of red tourism destination,is designed with red and patriotic education as the principal line to carry forward revolutionary traditions and spirits of Red Army,as well as create "red" garden landscapes with strong patriotism,time spirits and leisure elements.

Letter of Congratulations from H.E. Faure Essozimna Gnassingbé,Chairman of the Togo Union for the Republic and President of the Republic of Togo

On 12 August,the International Civil Society Solidarity Conference on Global Development Initiative is held in Beijing under the theme of working together to build a global development community and deliver on the UN 2030 Agenda for Sustainable Development.I am very pleased and honoured to congratulate President Xi Jinping and the organisers for the success of this Conference.

Emergency Money in Hungarian Pharmacies from World War l to the Hungarian Soviet Republic

All of the existing emergency notes of pharmacy in Hungary between 1914 and 1919 were collected, presented and studied. The concept of emergency money, the causes and circumstances leading to its development were defined. The historical backgrounds of these reasons were studied and presented in chronology order. The various issued emergency money of pharmacy was classified and demonstrated in pictures. When an economic crisis turns up in the life of mankind, special solutions will occur. World War I breaking out a hundred years ago and the Hungarian Soviet Republic created such a situation in Hungary. The official currency was replaced with a new one, the amount of which could not cover the daily purchase of people. The lack of change led to print numerous emergency notes in different fields of life. In this study, all of the so-far discovered pharmaceutical emergency money was collected and presented systematically. The paper is considered to be unique since in the field of the history of pharmacy similar ones have not been born recently. The released notes provide an instantaneous picture of the industry （art, typography, chemical industry etc.） of the given country as well. These pieces of paper are regarded to be valuable treasure among numismatics.

From Regional to Intercontinental Trade： The Successive European Trade Empires From the 16th to the 18thCentury in Asia

For a very long time, the areas available for continuous long-distance trade were limited to territories of Braudel＇s Mediterrande （1949）. Whatever the commercial organizations （merchants in the Roman or the Fatimid Empires, the Hanseatic League, the Florentine Companies） were, their trade was not able to directly handle branches more than a month＇s sailing from their main base （in the best conditions）. During the three centuries after Vasco de Gama had reached India, European trading areas dramatically expanded to the shores of Asia, and a long period of harsh competition set the East India Companies of the main European powers of the time against one another. What were the elements that allowed these companies to maintain transactions over such vast areas？ And why were some of these companies far more successful than the others？ A large set of secondary sources focusing on one company or on a particular aspect of trade （Chauduri, 1978; Israel, 1989; Subrahmanyan, 1993; Ames, 1996） exist, however, none of them treat their successive successes and failures. The aim of this paper is to briefly review these sources, to extract information from them and to compare the economic adaptations and innovations that allowed these companies to be the greatest of their time.

Testative Discussion on how to be an Eligible Interpreter--Based on the People’s Republic of China of the National People’s Congress and Committee of the People’s Political Consultative Conference from 2012 to 2014

In recent years,with the rapid development of the Chinese economy,the“two sessions”in March of every year which sponsored by the ministry of foreign affairs attract more and more journalists from all over the world.The press conference in the“two sessions”likes an important window to show China’s policies and claims to the world.Meanwhile,the premier who answers questions in the press conference,respectively,shows the world the eloquence and polite manners of China’s premier,such as Premier Wen Jiabao and Premier Li Keqiang.Their astute response,excellent,and emotional expression makes a deep impression on audiences.Moreover,as a bridge between the speaker and the listeners,the interpretation once is incorrect will cause some mistakes even conflicts.Therefore,the interpreter plays a most important role in the press conference.How to improve the interpretation level in the press conference is a significant topic.The thesis mainly introduces the content of press conference interpreting from 2012 to 2014.At present,the practical study of press conference interpretation is far from enough.The last part gives the summary of the study and points out the main findings for the further study.

Epidemiological and Histopathological Profile of Prostate Cancer: A Retrospective Study in the Pathology Department of the University Clinics of Kinshasa

Background: Prostate cancer, the most common male cancer, represents a real public health problem in terms of its frequency and severity in different countries around the world. It disproportionately affects people of African descent wherever they live in the world [1]. To the best of our knowledge, its extent and particularities in the African environment are not well known. Objective: To determine the epidemiological and histopathological profile of prostate cancer in the CUK anatomopathology department. Methodology: This is a retrospective study conducted at the University Clinics of Kinshasa Anapathology Department from January 1, 2015 to December 31, 2022, a period of 8 years. Word processing and tables were entered using the Hp brand computer, with Microsoft Office WORD 2016 software. Data analysis was performed with SPSS version 22.0 software. Results were presented in tables and figures. Results: Prostate was diagnosed in 132 cases, i.e. 1.58% of all CUK laboratory analyses and 8% of cancers diagnosed. The age group most affected was 66-75 years, i.e. 59% of all subjects. Adenocarcinoma was the most frequent histological type, and biopsy dominated in 111 cases (84.1%). Conclusion: Prostate cancer is a real public health problem. Worldwide, and in the Democratic Republic of Congo, it is the most frequently diagnosed cancer in men, and the leading cause of cancer-related death in men. In the DRC, because of the delay in consulting our patients and the weakness of systematic screening, patients are seen at an advanced stage of the disease. Treatment is multidisciplinary, involving surgery, radiotherapy and chemotherapy (including targeted therapies). Patient awareness and screening campaigns will help to considerably reduce the delay in diagnosis and the morbidity and mortality associated with prostate cancer.

Assessing the performance of magnetopause models based on THEMIS data

The magnetopause is the boundary between the Earth’s magnetic field and the interplanetary magnetic field(IMF),located where the supersonic solar wind and magnetospheric pressure are in balance.Although empirical models and global magnetohydrodynamic simulations have been used to define the magnetopause,each of these has limitations.In this work,we use 15 years of magnetopause crossing data from the THEMIS(Time History of Events and Macroscale Interactions during Substorms)spacecraft and their corresponding solar wind parameters to investigate under which solar wind conditions these models predict more accurately.We analyze the pattern of large errors in the extensively used magnetopause model and show the specific solar wind parameters,such as components of the IMF,density,velocity,temperature,and others that produce these errors.It is shown that(1)the model error increases notably with increasing solar wind velocity,decreasing proton density,and increasing temperature;(2)when the cone angle becomes smaller or|Bx|is larger,the Shue98 model errors increase,which might be caused by the magnetic reconnection on the dayside magnetopause;(3)when|By|is large,the error of the model is large,which may be caused by the east-west asymmetry of the magnetopause due to magnetic reconnection;(4)when Bz is southward,the error of the model is larger;and(5)the error is larger for positive dipole tilt than for negative dipole tilt and increases with an increasing dipole tilt angle.However,the global simulation model by Liu ZQ et al.(2015)shows a substantial improvement in prediction accuracy when IMF Bx,By,or the dipole tilt cannot be ignored.This result can help us choose a more accurate model for forecasting the magnetopause under different solar wind conditions.