Epidemiological and Clinical Aspects of Male Infertility in Patients Consulting at the Urology Department of the Yaounde Central Hospital

Introduction: About 10 to 15% of couples in the world and 20 to 30% in Cameroon consult for infertility problems. Infertility is of male origin in 40% of cases. Our objective was to evaluate the epidemiological and clinical aspects of male infertility in our setting. Methods: This was a cross-sectional and descriptive study, with retrospective data collection from the files of patients received for male infertility, over 5 years and 6 months (from January 1st, 2016 to April 30th, 2021) at the Urology Department of the Yaounde Central Hospital. Phone calls were made to patients with incomplete records for completion following a verbal consent. Data reported on data collection forms were entered into a data entry form designed on CSPro software version 7.2. The database was later exported for descriptive statistics using the IBM SPSS software version 23. Qualitative variables were summarized in frequencies and percentages while quantitative variables were summarized in means with their standard deviations for normally distributed data, or medians and interquartile ranges otherwise. Results: Out of 110 patients whose records were analyzed, the median age was 37.0 years, with an interquartile range of 8.3, with 55.5% in the age group 30 to 39 years. Of these 95 (86.4%) were married, 58 (52.7%) were from the West region, 76 (69.1%) were employed. Past history was dominated by mumps 40 (36.4%), varicocele surgery 25 (22.7%), alcoholism 87 (79.1%) and smoking 15 (13.6%). A disorder of spermatogenesis was found in all our patients: 37 (33.6%) azoospermia, 27 (24.6%) asthenospermia and 26 (23.7%) oligospermia patients. Paraclinical evidence of chlamydia and gonococcal infections were found respectively in 38 (34.5%) and 14 (12.7%) patients, varicocele and testicular dystrophy respectively in 95 (86.4%) and 38 (34.5%) patients. Infertility was primary in 67 (60.9%) patients. Conclusion: Most patients with infertility were in their thirties, had risky social habits and comorbidities. An early start of health promotion activities, comorbidities prevention and early detection of spermogram abnormalities would make it possible to reduce the frequency of male infertility.

External Otitis: Epidemiological, Clinical, Etiological, and Therapeutic Aspects at the Oto-Rhino-Laryngology Department of Mamou Regional Hospital

Introduction: External otitis (OE) is an acute or chronic inflammation or infection of the external ear resulting from an imbalance in the external auditory canal secondary to microtrauma, maceration, eczema, or a foreign body in the external auditory canal. Objective: To study cases of external otitis at the Mamou Regional Hospital. Materials and Methods: This was a prospective descriptive study conducted over a period of six (6) months from July 1st to December 31st, 2016. It included all patients admitted to the ENT department of the Mamou Regional Hospital. Results: During the study period, 712 patients were admitted to the department for various pathologies, of which 103 met our selection criteria, representing a frequency of 14.46%. The mean age of the patients was 33.74 years with a range of 1 to 90 years. Males predominated in the sample, accounting for 59.22%. The vast majority of patients resided in urban areas, constituting 61.17% of the sample. In our study, all patients consulted for otalgia (100%), and over half (53.39%) for hypoacusis. We formally identified rhinitis in 66.66% of cases, while diabetes was found in only 4 patients (11.11%). Otomycosis was the most commonly identified condition (53.39%), followed by furuncles (33.98%). Ear drops containing antibiotics were administered to all patients, although 66.60% received antibiotic therapy. Conclusion: External otitis is a relatively common condition, particularly among children and the elderly. Diagnosis can be made based on pain upon traction of the pinna and pressure on the tragus.

Infectious ENT Emergencies: A One-Year Experience at the ENT Department of Mamou Regional Hospital

Introduction: ENT infectious emergencies encompass all infectious pathologies affecting the ear, nose, sinuses, throat, and neck. A good understanding of these emergencies is essential for organizing appropriate care. In Guinea, few studies have described ENT infectious pathologies in rural areas. Objective: To study ENT infectious emergencies in the Otorhinolaryngology department of the Mamou Regional Hospital. Materials and Methods: This is a retrospective and prospective descriptive study, conducted from August 1, 2021, to July 31, 2022. All patients admitted to the ENT department of the Mamou Regional Hospital for an infectious emergency were included. Results: Among the 1854 recorded consultations, 261 cases involved ENT infectious emergencies, representing a prevalence of 14.07%. The most represented age group was 0 to 10 years (31.03%), with a majority of female patients (59%) and a predominantly urban origin (81.61%). Students accounted for 32.18% of the cases. The main reasons for consultation were odynophagia/dysphagia (32.42%) and otalgia (22.94%). The primary etiologies were tonsillitis (28.73%) and otitis (27.20%). Treatments administered included probabilistic antibiotic therapy (38.80%), analgesics (32.03%), and corticosteroid therapy (10.47%). The outcome was favorable in 98.85% of cases, with only 0.38% lost to follow-up. Conclusion: The results of our study confirm the frequency of ENT infectious pathologies. Their management requires joint actions for population awareness, staff training, and services equipment, particularly in rural areas.

Otorhinolaryngological (ORL) and Cervicofacial Injuries Resulting from Road Accidents within the Otorhinolaryngology (ORL) Department of the Regional Hospital of Mamou

Introduction: Otorhinolaryngological (ORL) and cervicofacial traumas encompass injuries affecting the neck, face, and ORL region, resulting from external influence. The objective of this study was to conduct an epidemiological and clinical analysis of ORL and cervicofacial injuries observed in victims of road accidents treated at the Otorhinolaryngology (ORL) department of the Regional Hospital of Mamou. Materials and Methods: This prospective and descriptive study was conducted over a period of 12 months, from January 1st to December 31st, 2021, within the Otorhinolaryngology (ORL) department of the Regional Hospital of Mamou. It included patients hospitalized for ORL and/or cervicofacial traumas resulting from road accidents during the study period. Results: A total of 348 cases were included, representing 36.22% of all traumas related to road accidents (AVP) within the Regional Hospital of Mamou. The average age of the patients was 26.44 years, with a sex ratio of 3.83, favoring males. The dominant socio-professional category was students, encompassing 32.47% of cases. Road accidents were mainly associated with motorcycle use (31.32% motorcycle-to-motorcycle, 24.43% motorcycle skidding, 13.51% motorcycle-pedestrian). Facial region injuries were the most common, accounting for 69.03% of cases, followed by rhinological injuries (17.28%) and otological injuries (13.69%). Associated injuries were predominantly closed head traumas (52.55%) and lower limb fractures (20.41%). Imaging was underutilized. Regarding surgical interventions, reconstructive surgery was the most predominant, accounting for 52.51% of cases, with a management timeframe of 30 minutes to 12 hours for 99.72% of patients. Conclusion: Road traffic accidents remain a serious public health issue, primarily affecting young males. Emphasis should be placed on road safety measures to reduce the frequency of these accidents.

Hand Hygiene by Ward Staff at Dapaong Regional Hospital in Togo

Introduction: Hand hygiene (HH) is an effective way to fight infections in healthcare settings. The general purpose of our study was to explore the knowledge, attitudes and practices of health care providers on HH at Dapaong regional hospital (DRH). Methodology: This was a prospective, descriptive cross-sectional study conducted from March to June 2022 in the DRH wards. Data were collected using a questionnaire and observation grid. Results: 90 care providers were surveyed. Males and non-physician personnel predominated with 57.8%, and 94.4% respectively. The survey on staff’s knowledge reported: 31.1% of practitioners did not wash their hands on arrival and departure in services. 24% did not know the difference between simple hand washing (SHW) and hygienic hand washing (HHW). 23.3% did not know the type of soap to use for HHW. The caregivers did not know the type of hand washing (HW) required after a septic and non-septic procedure in respectively 41.6%, and 37.8%. They did not know that there are two types of hand antiseptics (45.4%), nor the amount of antiseptic for HW (78.9%). The survey on staff’s attitude regarding HW found that: 70% did not remove all jewels prior HW, and 51.1% did not know that wearing gloves cannot replace the HW. For HW Staff Practice: 62.2% did not wash their hands before treatment. 91.1% did not spread the soap on their hands and forearms after wetting them. 65.55% did not rinse hands from nails to elbows. Conclusion: The HH was poorly known, the attitude of the staff was dangerous in relation to the HH and the practice of HH was very inadequate at the RHC-Dapaong. As a result, there is a need to retrain staff to increase their capacity to prevent care-related infections and enhance patient safety in the hospital.

Epidemiological Aspect and Evaluation of the Management of Urologic Emergencies at the Urology Unit of Labe Regional Hospital

Aim: To contribute to improving the management of urological emergencies at Labé Regional Hospital. Patients and Method: This was a dynamic, descriptive study lasting six months from July 1 to December 31, 2017. Results: Urological emergencies represented 45.14% (n = 218) of all admissions to the urology unit. The mean age of our patients was 56.60 years with extremes of fifteen days and 93 years. The 71 - 80 age group was the most represented with 28.03% (n = 61) followed by 61 - 70 years with 24.31% (n = 53). Our patients’ activities were dominated by agriculture, with 35.77% (n = 88), and the city center was most affected by urological emergencies, with 39.44% of cases (n = 86). 70.18% (n = 153) of our patients had bladder retention on admission, and 53.21% (n = 116) underwent urethral catheterization, including 3 women. The etiology of bladder retention in these 3 women was dominated by two cases of bladder lithiasis and one case of neurological bladder. Conclusion: The management of urological emergencies requires specific material and human resources. Their knowledge will enable us to better understand this problem and could serve as a basis for a broad reflection on the organization of the management of urological emergencies in our region.

Fishbone-Type Pharyngeal Foreign Body with Cutaneous Migration in the ENT Department of the Mamou Regional Hospital: A Case Report

We report a case of pharyngeal foreign body with cutaneous migration in the form of a fishbone in a 24-year-old rural resident, presented with odynophagia, dysphagia, pain and left antero-latero-cervical swelling fistulated to the skin following ingestion of a fishbone during a meal that had been evolving for 2 weeks. Vital parameters were normal, with an unremarkable psychological examination. Clinical examination revealed a left antero-latero-cervical swelling that was painful to palpation, fistulous to the skin and draining frank pus, revealing a sharp fishbone. A standard X-ray showed that the foreign body had exited the pharynx and was located in the soft tissues of the lower neck. An exploratory cervicotomy was performed, allowing extraction of a serrated fishbone. The post-operative course was favorable.

Patterns of Mortality Occurrence in a Cardiology Unit of a Low-Income Country: A Critical Analysis at the YaoundéCentral Hospital

Background: In-hospital mortality is high in low-income countries. Currently, little is known in Cameroon concerning the characteristics of patients who die in cardiology units. Our objectives were to determine the in-hospital mortality rate;describe the general characteristics of death patients, and factors associated with mortality. Material and Methods: We conducted a retrospective cross-sectional study by reviewing the medical records of all patients admitted to the cardiology unit of the Yaoundé Central Hospital (CHY) between January 2018 andJanuary 2019. The files of all death patients were studied for socio-demographical, clinical and therapeutical variables. Bivariate analysis was conducted to order to check the association between independents variables and time of death. A p-value < 0.05 was considered statistically significant. Results: A total number of 860 patients were admitted in the cardiology unit of CHY during the study period. Amongst the 860 patients admitted 78 had a fatal outcome, hence, an in-hospital mortality rate of 9.06%. The male gender was predominant amongst the deceased patients (n = 45). The mean age at death was 69 ± 15.19 years. The median time before death was 6 days and they ranged between 1 to 25 days. Hypertension was the most frequent comorbidity (65.4%). Stroke was the principal cause of admission (40.3%), whereas the main presenting complaint was dyspnea (26.9%). Before being admitted to the cardiology department, the majority of the deceased patients were from the emergency department. The major clinical sign of death was respiratory distress (39.74%). Shock on admission was the sole factor found to be associated with the mean time of death (p = 0.012). The patients with deep venous thrombosis compared to other diagnoses were less like to die early (r = 16, p = 0.016). Conclusion: The patient admitted in the cardiology unit of Yaoundé Central Hospital died mainly from stroke and the death is earlier when the patient has signs of shock on admission. These results emphasize the need for a good primary evaluation at the emergency room, to better manage patients with cardiovascular diseases in the cardiology ward.

Injury Patterns and Treatment Outcome of Road Traffic Crash Victims at the Emergency Department of the Regional Hospital Limbe, Cameroon

Background: Traumatic injuries constitute a leading cause of mortality and morbidity worldwide with a global burden that is on the rise. The aim of this study is to analyse preliminary data of the Limbe trauma registry, to describe the injury patterns and determine the outcome of care of the injured who were treated in the emergency department of the regional hospital Limbe in Cameroon. Methodology: This was a descriptive secondary analysis of prospective data collected on injury at Limbe Regional Hospital in two years, between October 2008 and October 2010. All cases of injury presenting to the emergency department of Limbe Regional Hospital were included in a prospective trauma registry. Data was collected with a pre-tested data entry form and included the age, sex, mechanism of injury, delay before arrival to hospital, body part injured, description of lesions and outcome at the emergency. Descriptive analyses were done using STATA 14. Comparisons between groups were evaluated using Chi-squared test or Kruskal-Wallis and p-values <0.05 were considered statistically significant. Results: A total of 2400 cases of injury were recorded during the study period with more males (68%) than females. The ages ranged from 0 to 90 years with a peak between 20 to 39 years. Road traffic crash was the most common cause of injury representing 60.81% of the population (n = 1434);other causes were burns, falls, domestic injuries, assaults, and labour accidents. The accidents mostly involved motor cycle alone (42.03%). Concerning the outcome of care at the emergency department, 88.73% (n = 1260) were discharged. Conclusion: The burden of road traffic injuries in south west Cameroon is high. Motorcycles are mostly involved alone or with pedestrians and/or cars.

Multidrug resistance Acinetobacter species at the intensive care unit,Aseer Central Hospital,Saudi Arabia:A one year analysis

Objective:To identify and to determine the antimicrobial susceptibility of Acinetobacter baumannii(A.baumannii) clinical isolates from ICU at Aseer Central Hospital.Methods:The study was conducted in the Intensive Care Unit,Aseer Central Hospital,Saudi Arabia over 13 months period(2014-2015).Acinetobacter species(n= 105) were isolated from various clinical samples.Isolates were identified using selected phenotypic criteria and confirmed using the Vitek 2 automated system.This system was used to determine the susceptibilities of 21 antimicrobial agents.Patients,isolates and drug data were analyzed using the SPSS statistical software package to determine some epidemiological and microbiological patterns.Results:Of the 105 stains,A.baumannii accounted for 49(46.67%),A.baumannii complex,19(18.09%),A.baumannii/haemolyticus 32(30.47),Acinetobacter haemolyticus 4(3.81%),Acinetobater lwoffii 1(0.95%) and unidentified Acinetobater species 2(1.3%).Of the 105 Acinetobacter strains,103(98.1%) were found multidrug resistant(MDR).A.baumannii strain were 100% sensitive to colistin and 74.5% to trimethoprim + sulfamethoxazole.The remaining 19 antimicrobial agents revealed low or no sensitivities:amikacin 16.3%; ampicillin 7.7%; ceftazidime 7.3%.Distribution of similar sensitivities was shown by other Acinetobacter species.Mean number of isolates from males and females indicates no statistical variation(P=0.867) whereas age groups showed significant differences(P= 0.008) as it is clear from the high percentage of infected individuals more than 60 years followed by those aged 20 to 29 years old(19.05%).Upper respiratory tract(30.48%),lower respiratory tract(47.65%) and subcutaneous tissue(9.5%) were the main sources of Acinetobacter spp.but mean numbers of isolates from these specimens indicate no discrepancy between specimens(P=0.731).Conclusions:Acinetobacterspecies including A.baumannii were found MDR(98.1%) according to the current Acinetobacter spp.antimicrobial categorization.Approximately half of these strains were A.baumannii.All Acinetobacter species were 100% sensitive to colistin and to some extent to trimethoprim + sulfamethoxazole(74.5%).ICU-acquired pneumonia among patients over 60 years of age who spend prolong times at artificial ventilations made up the majority of the cases.

New Political Dynamism in Central Asia:Security Issues and Prospects for Regional Cooperation

The article examines the issues of regional security and prospects of cooperation between the countries of Central Asia in the context of a new world order. As factors of sustainable development and security, the author considers the following issues: preservation of the geopolitical balance in Central Asia; development of a multivariate system of transportation and communication corridors; cardinal increase in the efficiency of counterterrorism and religious extremism; a solution to the Afghan problem; and resolution to the problems of fair water use and ecology in the region.

Study on Regional Image of Henan Province against the Background of Central Plains Rising

Relevant theories of regional image were elaborated, and significance of regional image for the development of Henan Province was analyzed. On the basis of characteristic cultural resources in the local area, the ways of building regional image of Henan were explored from the perspectives of orientation of cultural characteristics, regional image identification system and regional image evaluation.

Characteristics of Severely Anemic Pregnant Women and Perinatal Outcomes in Banfora Regional Hospital, Burkina Faso: An Epidemiological Study

Severe anemia during pregnancy remains an acute maternal health problem in low income countries and its management is a challenge. This study aimed to analyze the characteristics of hospitalized pregnant women with severe anemia and issue of the management in a regional hospital of a low income country. Material and Methods: This was a retrospective descriptive study from January 1, 2007 to December 31, 2008, at a regional hospital maternity. Data of the 283 pregnancy severe anemia cases have been analyzed using usual Pearson’s Chi square test or Fisher’s exact test. Results: Of the 283 women with pregnancy severe anemia, 98% were illiterate, 98% were household women;majority were in the third trimester (64%);41% had no previous delivery;49% did not had antenatal care. There were no statistics association between hemoglobin values stage and gestational age, gravidity and parity. During the hospitalization, from the 283 women with pregnancy severe anemia, deliveries occurred on 22.6%;abortion on 1%. From the 64 deliveries, 45.3% were alive preterm birth, 20.3% preterm stillbirth, 25.0% at term birth and 9.4% at term stillbirth. Between the 45 alive babies, 91% were low birth weight. In global, from the 283 women, mortality rate was 2.8%. Conclusion:?Severe anemia during pregnancy results in maternal mortality, preterm, low birth and stillbirth even between hospitalized women. As most of the pregnancy anemia risk factors are chronic poverty related factors, intervention must be focused on prevention including health pregnant women iron supplementation and adequate nutritional diet promoting at both health facilities and community level.

Maternal Mortality Risk Factors in Regional Hospital of Burkina Faso

Individual causes and community determinants are synergic in maternal death occurrence. This study aimed to identify maternal mortality risk factors in a regional hospital. Material and Methods: This was a retrospective cohort study from data of 1807 hospitalized women. To identify maternal mortality risks factors, mortality hazard ratio (HR CI95%) has been calculated in univariate analysis and Cox proportional hazard model. Results: During hospitalization, 30 maternal deaths occurred. From Cox regression, adjusted mortality HR confirmed that women age older than 35 (HR = 2.5, CI95%: [1.2-5.7] and younger than 19 (HR = 3.02, CI95%: [1.5-6.7]);distance to hospital ≥10 Km (HR = 4.1, CI95%: [1.8-9.4];multiple deliveries (HR = 2.4, CI95%: [1.1-7.3]), less ante natal care (<3 visits) (HR = 3.03, CI95%: [0.97-9.48]);obstetrical maternal mortality directs causes (HR = 2.31, CI95%: [1.7-6.21]) and emergently reference (HR = 3.5, CI95%: [1.8-8.32]) were maternal mortality risk factors. Conclusion: In this regional hospital of low income country, identified maternal mortality factors are related to women socio-economic determinants and quality prenatal or obstetric care access. Interventions to reduce maternal mortality rate should be conducted within both household and women socio-economic status development and in maternal health and obstetric care strengthening.

Diagnostic Analysis on a Regional Rainstorm Weather in North-central Henan Province

[Objective] The research aimed to analyze a regional rainstorm weather process in north-central Henan Province. [Method] Based on the conventional meteorological observation data and the rainfall data of Henan Meteorological Station, the diagnostic analysis of atmospheric thermodynamics and dynamics on a rainstorm weather process in north-central Henan Province on July 19, 2010 was carried out. The characteristics of physical quantity field and the evolution of weather situation in north-central Henan Province when the rainstorm happened were studied. [Result] Western Pacific subtropical high strengthened to extend westward. The dynamic uplifting of low vortex at the middle and low layers, the strong water vapor transportation of southwest low-level jet caused the regional rainstorm weather process in north-central Henan Province. The diagnostic results of physical quantity showed that the deep, thick wet layer and the sustained water vapor convergence provided the abundant water vapor for rainstorm generation. The positive vorticity advection center developed and spread from northwest to southeast, which was favorable for the development of vertical movement. The structure maintenance of positive vorticity at the middle and low layers, negative vorticity at the middle and high levels provided the power condition for the regional rainstorm generation. The pumping effect of convergence at the middle and low layers, divergence at the high layer was favorable for the strengthening of vertical ascending motion at the low layer. The uplifting effect of dew point front at the middle and low layers triggered the release of unstable energy. The confrontation of warm and cold air was one of the important reasons for the regional rainstorm. TBB characteristic analysis showed that TBB was from -60 to -50 ℃ in north-central Henan Province in the whole strong precipitation time, and the moving speed was equivalent to that of southwest vortex. The low-value belt of TBB corresponded with the rainstorm occurrence zone in Henan, and the minimum-value center of TBB was basically consistent with the strongest center of precipitation. [Conclusion] The research provided the scientific basis for the short-term forecast of rainstorm.

The Central Asian Regional Security Complex Revisited:Understanding the Implications of the US Retreat From Afghanistan

On February 29,2020,President Donald Trump announced the United States signed a peace agreement with the Taliban,signifying the United States‟intention of leaving Afghanistan in the near future.Though the global pandemic has altered US withdrawal plans,the question still remains:What will become of the Central Asian regional security complex following America‟s exit?Buffered by the presence of the United States since 2001,the Central Asian republics now once again find themselves at a crossroads to either rely on individual defense services or to develop increased military cooperation with interested states.Recognizing Central Asia‟s history of collaboration among its regional and near-regional countries,I argue that the Central Asian Republics of Afghanistan,Kazakhstan,Kyrgyzstan,Tajikistan,Turkmenistan,and Uzbekistan will seek to develop stronger security ties with neighboring regional security complexes(RSCs),namely the South Asian,Russian,and Chinese RSCs.With decreased American influence,each of the states in these RSCs is rushing to fill the void of influence in order to capitalize on Central Asia‟s geostrategic position in Eurasia as well as secure itself from the threat of non-state actors still prevalent in the region.I further argue that the states in the Central Asian RSC additionally seek these same benefits and security,but receive them to a much lesser extent than their more powerful regional neighbors.Understanding how the American withdrawal from Afghanistan will impact Central Asian RSC relations can provide insight into how great power vacuums are filled both by great powers and regional powers alike.

Development of regional specificity of spinal and medullary dorsal horn neurons

Extensive studies have focused on the development and regionalization of neurons in the central nervous system(CNS). Many genes, which play crucial roles in the development of CNS neurons, have been identified. By using the technique "direct reprogramming", neurons can be produced from multiple cell sources such as fibroblasts. However, understanding the region-specific regulation of neurons in the CNS is still one of the biggest challenges in the research field of neuroscience. Neurons located in the trigeminal subnucleus caudalis(Vc) and in the spinal dorsal horn(SDH) play crucial roles in pain and sensorimotor functions in the orofacial and other somatic body regions, respectively. Anatomically, Vc represents the most caudal component of the trigeminal system, and is contiguous with SDH. This review is focused on recent data dealing with the regional specificity involved in the development of neurons in Vc and SDH.

A stratigraphical-geochemical study on the Chaco Paraná continental rift basin—An approach study based on regional sedimentology and drill-hole core analyses, South América

This paper is focused on a geologic “regional rift basin system pattern” and its stratigraphical-geochemical relationship. This is mainly based on the littoral shallow marine sedimentary succession paleogeography and deposits. These successions characterize the large extensional intracratonic Chaco Paraná Basin rift system. The basin is located in South America west of the Brazilian Shield. The analyzed rift basin system evolved from the Upper Cretaceous (Late Campanian-Senonian-Maastrichtian-Early Paleocene) to Quaternary time. The siliciclastic littoral shallow marine successions were deposited from Early Senonian-Maastrichtian to Late Miocene during three main successive littoral shallow marine transgressions of continental extension.; These transgressions happened over the wide pediplanized terrains of South America. These lands exist west of the more positive areas, between the Brazilian Shield and the foreland massifs that were settled in the more westernwards areas. Later, these regional foreland massifs were coupled and raised to the Andean Orogen Belt during the last 5 million years.; The extensive intracratonic pediplanized low topographic relief areas were the reservoirs of siliciclastic littoral shallow marine succession deposits during the three successive widespread vast continental littoral shallow marine transgressions.; The first transgression began at the Latest Campanian-Senonian and/or Early Maastrichtian time. After this episode, the sedimentary depositional systems continued during the Cenozoic until the Latest Miocene. These successions constitute a major allostratigraphic unit. The limit with underlying units is the regional unconformity between the regional volcanic event (Jurassic-Cretacic and interleaved eolianite sandstones) at the base and the undifferentiated Quaternary sediments (called as the Pampeano and Post-Pampeano Formations sensu lato). Based on many facies analyses there had been checked out different levels in the eustatic sea level variations within the allostratigraphic unit.; Three major stages of extensional climax were recognized and related to the stages of conspicuous eustatical sea-level variations. They happened during the Latest Senonian-Paleocene, Eocene and Miocene.; The first transgression occurred during the Upper Cretaceous-Paleocene although the sedimentary deposits related to this event are scarce, which are only a few meters in thickness. However, the Upper Cretaceous-Paleocene succession is very well recognized in the actual pre-Andean zone in the north-west of Argentina and Bolivia (the Sierras Subandinas and the meridional imbricated fault systems just joint to the actual orogen, i.e., Quebrada de Humahuaca outcrops).; During the Eocene and Middle to Latest Miocene occurred the second and third extensive regional littoral shallow marine transgressions. They are present either in well log registers as in most widespread outcrops on the entire Southamerican continent.; The regional analysis led to the deduction of long periods of tectonic quiescence, at least three of them. They may be inferred and synchronously related with eustatic highstand sea level variations that occurred during the Late Paleocene-Early Eocene, Latest Eocene-Early to Mid Oligocene and Middle-to-Late Oligocene-Early Miocene.; The structural style is related with major extensional N-S strike faultings (regional tilted and faulting blocks). On the other hand, quite a number of strike-slip faults (mainly of regional characteristic) are present crossing the area. They have a clear influence on the accommodation and transfer zones of the rift basin system. The strike is north-west to south-east on the border of the basin, to the west, in the contact with the Pampean Ridges and the narrow-meridionally-extense Sub-Andean folded trend (mainly Paleozoic units belonging to the so-called Sierras Subandinas geological province). Also, at the western edge of thestudied area, there exist many large shear zones and upthrust faults. The strike-slip regional faults dislocated the Pampean and Sub-Andean blocks due to the interaction of crossing regional tilted and fault blocks. For this reason, an en echelon regional block model is characteristic. Incipient contaminated igneous activities were associated with this cortical weak zones.; Domes, needles and necks of volcanic and sub-volcanic origin appear as the landscape of the region. A part of the igneous activity was dated on Latest Pliocene although mainly corresponding to Pleistocene and Holocene. This deduction is obvious because their morphological constitution was never eroded. The volcanic aparatous are morphologically unmodified from their extrusion to present days.; All the studied successions seem to resemble a long persisting erosive, transportation and deposition episode. This phenomenon is linked to a large regional (continental) unconformity dated at Late Cretaceous. The entire analyzed sedimentary succession deposits and their siliciclastic facies associations correspond clearly to a “heterolithic facies succession” which is very common within persisting tide-dominated depositional systems (passive margins). In fact, this is what happened during Cenozoic times (Torra, 1998b, 2001a). The heterolithic Miocene facies deposits constitute one of the best continental exposed examples.; Paleogeographical evidence showed that the Paranense and Amazonic Sea transgressions had been a littoral shallow marine connection during long time from Middle to Late Miocene. During the Late Cretaceous and Eocene periods marine connections were also active in the region. This fact is strongly supported by the tectonic and geomorphological framework of the proto-Southamerican continent, fossil remains and similar sedimentary deposits.; The geochemical results showed an outstanding similarity among the three sandy-muddy successions herein studied. Both major and trace elements always show the same geochemical patterns. Specially mentioned are the elements gallium, cesium, chromium, barium, vanadium, thorium, zirconium, rubidium and strontium because they present very constant values through all successions.; The Paranense and Amazonic epicontinental seas had been connected to the Pacific Ocean during the three marine episodes. The connections were formed by narrow inter-mountain valleys, present in the pre-Andean foreland massifs. These events occurred prior to the main orogenesis elevation of the Andean orogen belt in the last 5 to 1 Ma (Pliocene-Latest Pleistocene).; This paper shows, for the first time, a synthetic stratigraphical-geochemical “regional model” for the Chaco Paraná Basin rift system which should be largely improved in later studies. The Chaco Paraná Basin carries many unexamined-unexplored natural resources which need more regional and local studies for their evaluation. This is in spite of the area that has the problem of a significative vegetation coberture and scarce good outcrops. The development of modern techniques of data acquisition will help to overcome these difficulties.

Petroleum geological characteristics and exploration targets of the oil-rich sags in the Central and West African Rift System

Based on seismic,drilling,and source rock analysis data,the petroleum geological characteristics and future exploration direction of the oil-rich sags in the Central and West African Rift System(CWARS)are discussed.The study shows that the Central African Rift System mainly develops high-quality lacustrine source rocks in the Lower Cretaceous,and the West African Rift System mainly develops high-quality terrigenous organic matter-rich marine source rocks in the Upper Cretaceous,and the two types of source rocks provide a material basis for the enrichment of oil and gas in the CWARS.Multiple sets of reservoir rocks including fractured basement and three sets of regional cap rocks in the Lower Cretaceous,the Upper Cretaceous,and the Paleogene are developed in the CWARS.Since the Late Mesozoic,due to the geodynamic factors including the dextral strike-slip movement of the Central African Shear Zone,the basins in different directions of the CWARS differ in terms of rifting stages,intervals of regional cap rocks,trap types and accumulation models.The NE-SW trending basins have mainly preserved one stage of rifting in the Early Cretaceous,with regional cap rocks developed in the Lower Cretaceous strata,forming traps of reverse anticlines,flower-shaped structures and basement buried hill,and two types of hydrocarbon accumulation models of"source and reservoir in the same formation,and accumulation inside source rocks"and"up-source and down-reservoir,and accumulation below source rocks".The NW–SE basins are characterized by multiple rifting stages superimposition,with the development of regional cap rocks in the Upper Cretaceous and Paleogene,forming traps of draping anticlines,faulted anticlines,antithetic fault blocks and the accumulation model of"down-source and up-reservoir,and accumulation above source rocks".The combination of reservoir and cap rocks inside source rocks of basins with multiple superimposed rifting stages,as well as the lithologic reservoirs and the shale oil inside source rocks of strong inversion basins are important fields for future exploration in basins of the CWARS.

What are the underlying causes and dynamics of land use conflicts in metropolitan junction areas?A case study of the central Chengdu–Chongqing region in China

Land use conflicts(LUCs),as a spatial manifestation of the conflicts in the human-land relationships,have a profound impact on regional sustainable development.For China’s metropolitan junction areas(MJAs),the existence of“administrative district economies”has made the issue of LUCs more prominent.Based on a case study of the central Chengdu–Chongqing region,we conducted an exploratory spatial data analysis of the evolutionary process of regional LUCs.Furthermore,structural equation modeling was utilized to analyze the dynamic mechanism of LUCs in MJAs,with a particular emphasis on exploring the influences of administrative boundary.The results showed that from 2010 to 2020,LUCs in the central Chengdu–Chongqing region continued to worsen,and the spatial process conflict and spatial structure conflict indices increased by more than 30.0%.The intensification of LUCs in the central Chengdu–Chongqing region from 2010 to 2020 was mainly the result of the deterioration of conflicts in evaluation units with low conflict levels.LUCs in China’s metropolitan areas generally presented a circular gradient distribution,weakening from the core to the periphery,but there were some strong isolated conflict zones in the outer regions.LUCs in China’s MJAs were the result of interactions among multiple factors,e.g.,natural environment,socio-economic development,policy and institutional processes,and administrative boundary effects.Administrative boundary affected the flow of socio-economic elements,changing the supply-and-demand competition of stakeholders for land resources,consequently exerting an indirect influence on LUCs.This study advances the theory of the dynamic mechanism of LUCs,and provides theoretical support for the governance of these conflicts in transboundary areas.