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This article examines the impact of the COVID-19 pandemic on endoscopic pituitary surgery at a pituitary center of excellence. The study compared patients who underwent surgery before the pandemic (January 2015 to March 2020) with those who had surgery during the pandemic (March 2020 to September 2022). The results showed that patients who presented during the pandemic tended to be more frail and have more comorbidities. They were also more likely to have larger adenomas and require additional surgical approaches. Despite these changes, the length of stay and readmission rate remained stable, indicating the safety of the procedure during the pandemic. [Extracted from the article]

This article discusses the outcomes of the endoscopic endonasal approach (EEA) for nonfunctional pituitary adenomas (NFPAs) in elderly patients. The study involved a retrospective review of NFPAs in patients aged 65 and older who underwent EEA between 2007 and 2022 at a single medical center. The results showed that EEA was a safe and effective option for NFPA resection in elderly patients, with high rates of visual recovery postoperatively and acceptable rates of gross total resection (GTR). The study also identified risk factors for progression and subtotal resection, but found no associations between postoperative complications and age or frailty scores. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, introduces a novel outcome metric called the 30-day hospitalization ratio (HR) for patients with pituitary adenomas. The metric combines the length of stay and readmission rates within a 30-day period to provide a comprehensive measure of the economic burden of treatment. The study analyzed the clinical records of 468 patients who underwent endoscopic endonasal surgery for pituitary adenoma. Factors associated with a high HR included high preoperative ASA scores, postoperative lumbar drain placement, intradural extension, and employment status. Understanding these risk factors can lead to personalized monitoring and care, ultimately reducing burden and improving outcomes. [Extracted from the article]

The present work aims to evaluate expansive soil stabilization using different additives. Twenty soil mixtures consisting of 10%, 20%, 25%, and 30% zeolitic tuff (ZT) with 2%, 4%, and 6% lime in various combinations were used to stabilize the soil for pavement subbase application. A comprehensive test program, including Atterberg's limits, compaction, unconfined compression strength (UCS), California Bearing Ratio (CBR), resilient modulus, and permanent deformation, was performed on natural and stabilized soil specimens. Scanning electron microscopy (SEM) supplied with energy-dispersive X-ray spectroscopy (SEM/EDX) was used to confirm the study findings. Adding ZT increases the availability of the silica and alumina needed for the pozzolanic reaction; test results revealed that adding ZT increases the maximum dry unit weight, CBR, UCS, resilient modulus, decreases plasticity, and permanent deformation. As such, ZT can improve the physical and mechanical properties of lime-stabilized soil as a pavement's subgrade and subbase layers. [ABSTRACT FROM AUTHOR]

Background: The role of preoperative upper gastrointestinal endoscopy before bariatric surgery is still debated, and a consensus among the international scientific community is lacking. The aims of this study, conducted in three different geographic areas, were to analyze data regarding the pathological endoscopic findings and report their impact on the decision-making process and surgical management, in terms of delay in surgical operation, modification of the intended bariatric procedure, or contraindication to surgery. Methods: This is a multicenter cross-sectional study using data obtained from three prospective databases. The preoperative endoscopic reports, patient demographics, Body Mass Index, type of surgery, and Helicobacter pylori status were collected. Endoscopic findings were categorized into four groups: (1) normal endoscopy, (2) abnormal findings not requiring a change in the surgical approach, (3) clinically important lesions that required a change in surgical management or further investigations or therapy prior to surgery, and (4) findings that contraindicated surgery. Results: Between 2006 and 2020, data on 643 patients were analyzed. In all of the enrolled bariatric institutions, preoperative endoscopy was performed routinely. A total of 76.2% patients had normal and/or abnormal findings that did not required a change in surgical management; in 23.8% cases a change or a delay in surgical approach occurred. Helicobacter pylori infection was detected in 15.2% patients. No patient had an endoscopic finding contraindicating surgery. Conclusions: The role of preoperative UGE is to identify a wide range of pathological findings in patients with obesity that could influence the therapeutic approach, including the choice of the proper bariatric procedure. Considering the anatomical modifications, the incidence of asymptomatic pathologies, and the risk of malignancy, we support the decision of performing preoperative endoscopy for all patients eligible for bariatric operation. [ABSTRACT FROM AUTHOR]

Background Stereotactic radiosurgical rhizolysis of the trigeminal nerve is an established modality increasingly employed to alleviate the symptoms of refractory trigeminal neuralgia. This study analyzes the academic impact of the top 100 cited articles on the radiosurgical management of trigeminal neuralgia. Methods The Scopus database was searched for articles containing "radiosurgery" and one or more of "trigeminal neuralgia," "trigeminus neuralgia," and "tic douloureux." The top 100 articles written in English were arranged in descending order by citation count. Documents were evaluated for authors, publication year, journal and impact factor, total citations, nationality, study type, radiosurgical modality, and the affiliated institution. Quantitative and qualitative analyses were performed on the data. Results The most cited articles were published between 1971 and 2019. The average citation per year was 4.3. The most targeted anatomic area was the "root entry zone" or proximal portion of the cisternal segment of the trigeminal nerve. The most utilized modality was Gamma Knife radiosurgery. The country with the highest number of publications was the United States. Thirty-six percent of the articles were published in the Journal of Neurosurgery. Lunsford, Kondziolka, Flickinger, and Régis, respectively, were the most frequently listed co-authors. The most prolific institute was the University of Pittsburgh Medical Center. Conclusion Stereotactic radiosurgery is an important modality in the management of medically or surgically refractory trigeminal neuralgia. This analysis assesses its contributions over the past five decades to identify trends in treatment practices for neurosurgeons and to highlight areas where further study is needed. [ABSTRACT FROM AUTHOR]

Emotion recognition is a significant issue in many sectors that use human emotion reactions as communication for marketing, technological equipment, or human–robot interaction. The realistic facial behavior of social robots and artificial agents is still a challenge, limiting their emotional credibility in dyadic face-to-face situations with humans. One obstacle is the lack of appropriate training data on how humans typically interact in such settings. This article focused on collecting the facial behavior of 60 participants to create a new type of dyadic emotion reaction database. For this purpose, we propose a methodology that automatically captures the facial expressions of participants via webcam while they are engaged with other people (facial videos) in emotionally primed contexts. The data were then analyzed using three different Facial Expression Analysis (FEA) tools: iMotions, the Mini-Xception model, and the Py-Feat FEA toolkit. Although the emotion reactions were reported as genuine, the comparative analysis between the aforementioned models could not agree with a single emotion reaction prediction. Based on this result, a more-robust and -effective model for emotion reaction prediction is needed. The relevance of this work for human–computer interaction studies lies in its novel approach to developing adaptive behaviors for synthetic human-like beings (virtual or robotic), allowing them to simulate human facial interaction behavior in contextually varying dyadic situations with humans. This article should be useful for researchers using human emotion analysis while deciding on a suitable methodology to collect facial expression reactions in a dyadic setting. [ABSTRACT FROM AUTHOR]

Abstract Background Observations Lessons Craniofacial fibrous dysplasia (CFD) typically occurs in the facial bones and anterior cranial vault and can produce both disfigurement and functional limitations for patients disfigurement. Treatment consists of reducing the abnormal bone. Bone contouring can become challenging when the exposure does not extend to the corresponding normal contralateral structures for comparison or when normal landmarks are not available, which may compromise the overall aesthetic outcome. We describe a technique using dynamic mirroring to accurately contour the involved part of the cranium in a case of giant CFD.A 49-year-old male presented with a giant deforming fibrous dysplasia of the right mastoid and parieto-temporo-occiput that was causing functional limitations due to the size of the bony mass. This was managed with multidisciplinary bony reduction. Several neurovascular structures were in proximity to the areas of planned drilling of the expansile lesion, and dynamic mirroring of the uninvolved left skull was utilized to maximize safety and symmetry of reduction. High-speed drilling of the right occipital bone was performed until the navigation system alerted the surgeon that symmetric depth had been achieved. There were no complications from the procedure and this technique maximized the limits of symmetric reduction without significantly increasing surgical complexity or duration.Dynamic mirroring of bony structures in the posterior cranium is not commonly employed in neurosurgical practice. This technique may help improve the aesthetic outcomes of bony reduction in craniofacial dysplasia and a variety of similarly managed bony lesions, contour cranioplasties, and in unilateral craniosynostosis surgery. [ABSTRACT FROM AUTHOR]

Objective  Previous work categorized skull base chordoma (SBC) into three genetic risk groups based on 1p36 and homozygous 9p21(p16) deletions, accounting for a wide variability in prognosis (A = low-risk, B = intermediate-risk, C = high-risk). However, it remains unclear how these groups could guide management. Study Design  By integrating surgical outcome and adjuvant radiation (AdjXRT) information with genetic data on 152 tumors, we sought to develop an evidence-based management algorithm for SBC. Results  Gross total resections (GTRs) were associated with improved progression free survival (PFS) in all genetic groups. For Group C tumors, GTR and AdjXRT independently contributed to PFS (multivariate Cox proportional hazard ratio [HR] = 0.14, p  = 0.002, and HR = 0.40, p  = 0.047, respectively). For Group B tumors, AdjXRT improved outcomes only when GTR was not feasible (log-rank p  = 0.008), but not following GTR (log-rank p  = 0.54). However, 24 of 25 Group A tumors underwent GTR, and AdjXRT for these did not confer any benefit (log-Rank p  = 0.285). The high GTR rates in Group A could be explained by smaller tumor sizes (mean = 0.98cc/4.08cc/4.92cc for Group A/B/C, respectively, p  = 0.031) and lack of invasiveness. Group A tumors were also more frequently diagnosed in young people (p  = 0.002) as asymptomatic lesions (p  = 0.001), suggesting that they could be precursors to tumors in higher risk groups. Conclusion  Genotypic grouping by 1p36 and homozygous 9p21(p16) deletions can predict prognosis in SBC and guide management. GTR remains the cornerstone of SBC treatment and can be sufficient without AdjXRT in low and intermediate risk tumors. Low-risk tumors are associated with a less invasive phenotype, which makes them more amenable to GTR. [ABSTRACT FROM AUTHOR]

The surgeon is positioned on the right side, the camera holder on the surgeon's left side and the assistant between patient's legs. Step 6: Splenectomy The surgeon is between the patient's legs with camera holder to the patient's right and the assistant on the other side. Step 4: Mobilization of the hepatic flexure and caecostomy The assistant exposes the hepatocolic ligament and phrenocolic ligament by pulling the hepatic flexure downwards. [Extracted from the article]

Background: The primary curative treatment for thymic malignancies is surgery. For lung and esophageal cancer, substantive disparities in outcomes by race exist. Many of these disparities are attributed to the decreased use of surgery in non-White patients. Although thymic malignancies are treated by the same specialists as lung and esophageal cancer, it is unknown if there are racial disparities in the treatment of thymic malignancies.Research Question: Do racial disparities exist in the surgical treatment of thymic malignancies?Study Design and Methods: A retrospective cohort analysis was performed using the National Cancer Data Base of patients diagnosed with thymoma and thymic carcinoma between 2004 and 2016. Univariate comparisons of demographics were compared using χ 2 and rank-sum tests. Multivariable analysis was performed to determine if race was an independent variable associated with receiving surgical resection. Preoperative and postoperative care was compared between races.Results: Seven thousand four hundred eighty-nine patients met inclusion criteria. Four thousand nine hundred sixty-two (66%) were White, 1,311 (18%) were Black, 487 (7%) were Hispanic, 580 (8%) were Asian or Pacific Islander, and 143 (2%) were other races. Black patients with thymic malignancies were more likely to have a median income < $38,000 and not received surgery. Black and Hispanic patients had the lowest median age (54.3 and 53.6 years, respectively) and were most likely to be uninsured (8.2% and 12.5%, respectively). White patients received surgical therapy 1 week sooner and had a postoperative length of stay 1.5 days shorter than Black patients. Multivariable analysis controlling for age, sex, tumor size, insurance status, comorbidity score, histology, and facility type showed that race remained independently associated with the receipt of surgical resection. White patients had the greatest likelihood of receiving surgery with Black patients being least likely to receive surgery (OR, 0.60).Interpretation: A racial disparity exists in surgical therapy for thymic malignancies. [ABSTRACT FROM AUTHOR]

Background: strabismus is a condition in which the eyes are not properly aligned with each other. It typically involves a lack of coordination between the extraocular muscles. Strabismus can present as manifest (heterotropia), apparent, latent (heterophoria) varieties. Objective: the present study aimed to compare the minimally invasive strabismus surgery (MISS) as an alternative to limbal approach for horizontal concomitant strabismus. Patients and Methods: the study included 50 patients of different ages and sexes, presented with transverse strabismus, for elective surgical correction. They allocated into two equal groups; the first group included 25 cases who were managed by MISS (patients group); the second group included the other 25 cases who were managed by limbal approach (control group). Results: the results were evaluated at one week, three week and six week as regards to visibility of surgical wound, post-operative conjuntival redness, patient discomfort, surgical opening related complications and post-operative correction at first week, third and six months. Few complications were seen with the MISS technique and they were mostly related to the surgery not to the technique itself. Conclusion: the minimally invasive strabismus surgery has the same effect as limbal approach as obvious by the similar success rate. Its stability is as good as the stability of limbal incision. It has the advantages of sparing perilimbal episcleral vessles which make it a good choice instead of limbal approach whenever there is fear of anterior segment ischemia. [ABSTRACT FROM AUTHOR]

Background: Acromegaly is a disease of growth hormone excess that results in enlargement of extremities, abnormal glucose and lipid metabolism, and gonadal disruption. Manifestations of the disease are insidious and typically lead to a diagnostic delay of 7–10 years. Classically the polycystic ovary syndrome (PCOS) phenotype is described in women with irregular menses, clinical or biochemical evidence of androgen excess, and/or multiple ovarian follicles on pelvic ultrasonography. Women with acromegaly may present with some or all of these symptoms. Our objective was to evaluate the prevalence of PCOS in patients with acromegaly and to determine if diagnosis of PCOS results in a delay in diagnosing acromegaly. Methods: Using patient databases at two academic health centers, we identified 97 premenopausal women aged 18–49 years old presenting with acromegaly. Data were collected regarding pelvic sonography and reproductive history, including the diagnosis of PCOS. Patients carrying the diagnosis of PCOS before their diagnosis of acromegaly were identified and the remaining patients were screened using the Rotterdam criteria to identify additional patients meeting the criteria for PCOS prior to their diagnosis of acromegaly. Results: Mean age of the population (n = 97) at the time of diagnosis of acromegaly was 33.4 ± 7.5 years (SD). Thirty-three percent of patients (n = 32) either carried a diagnosis of PCOS or met diagnostic criteria for PCOS before their diagnosis of acromegaly. In the subset of patients in whom data on symptom onset were available, those who met criteria for PCOS were diagnosed with acromegaly a median of 5 years [4, 9] after the onset of symptoms compared to 2 years [0.92, 3] (p = 0.006) in the patients who did not meet criteria for PCOS. Conclusions: Our data demonstrate a high prevalence of signs and symptoms of PCOS in reproductive-aged women with acromegaly and a longer time to diagnosis in women who meet the clinical criteria for PCOS. As screening for acromegaly is relatively simple and done with measurement of a random, non-fasting IGF-1 level that can be drawn at any time during the menstrual cycle, screening patients with PCOS for acromegaly may lessen the delay in diagnosis for reproductive-aged women with this disease. [ABSTRACT FROM AUTHOR]

This paper will try to focus on two aspects of oil production policy under the General Agreement on Tariffs and Trade (GAIT) and the World Trade Organization.The first is how freely an oil producer can regulate the quantity of oil production and exports without violating GAIT rules and the second is how an oil exporter could benefit from GAIT rules to overstep barriers to market access imposed by oil- importing countries. [ABSTRACT FROM AUTHOR]

Study problem: It was specified in the main question: What’s the role of public relations in managing the crisis situations in the hotel sector in Makkah region Objectives of the study: • Noticing the role of public relations in the hotel sector in Jeddah and avoiding crises before and during it happens. • Knowing the strategies used by public relations in the hotel sector in Jeddah City during dealing with crises. • Knowing the most important obstacles that face the public relations in the hotel sector in Jeddah City. Methodology : This study is related to the research that depends on the evidence survey method for the hotel sector in Makkah region, specifically the Jeddah city. Sample: The study sample is confined to the groups of four and five star hotels in Makkah region (Jeddah city), with ten hotels with public relations department. The most important results: • Using scientific methods and researches in dealing with the crises stages came at the top of the chart with a rate of 87.67%, • The study showed that applying the abilities of departments and workers in the hotel of the plans laid by the public relations department for managing crises came in on top by 83.67%. Recommendations: • Attracting qualified and specialized staff in the field of public relations to work in the department of hotel public relations. • Specifying the duties and responsibilities of each department in order to avoid duplications in the work of the public relations department with other departments. [ABSTRACT FROM AUTHOR]

This article explores the use of radiomic feature analysis to predict overall survival and progression-free survival after surgery in patients with skull base chordomas. The study extracted radiomic features from preoperative MRI scans and used unsupervised analysis to identify distinct groups based on these features. The results showed that the radiomic features were able to model overall survival and progression-free survival, and were also associated with genetic markers commonly used in clinical decision-making. The authors suggest that radiomics-based imaging biomarkers could be a noninvasive and cost-effective way to personalize care for patients with skull base chordomas. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, examines the impact of frailty on surgical outcomes in patients with Cushing's disease (CD). The study analyzed data from the Registry of Adenomas of the Pituitary and Related Disorders (RAPID) and found that mild frailty independently predicted outcomes after transsphenoidal surgery for CD. Mildly frail patients had longer hospital stays and were more likely to be discharged to skilled nursing facilities. The study suggests that assessing frailty could be useful for preoperative risk stratification and prognostication in CD patients. [Extracted from the article]

This article discusses the establishment of a national pituitary surgical research platform called RAPID, which aims to improve patient care and surgical outcomes for pituitary disorders. The initial focus of the collaboration is on Cushing's disease. The study provides an overview of the patient cohort, surgical outcomes, and lays the foundation for future research. The data collected from nine academic pituitary centers shows that 528 patients with Cushing's disease were treated by 26 neurosurgeons from 2003 to 2023. The report highlights insights into surgical outcomes and disease recurrence rates across different surgeons and environments. The collaboration is expected to advance the standard of care for patients with pituitary disorders. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, examines the outcomes of patients with Crooke cell adenomas (CCA) compared to those with corticotroph adenomas (sCTA), both of which are types of pituitary corticotroph adenomas found in patients with Cushing's disease. The study, which included 2,826 patients from 12 international centers, found that CCA patients had poorer endocrinologic outcomes compared to sCTA patients, despite having better local control rates and fewer residual tumors. The authors suggest that further research is needed to better understand CCA and develop more targeted treatment approaches. [Extracted from the article]

This article discusses the issue of unplanned hospital readmissions following trans-sphenoidal surgery for Cushing's disease. The study analyzed data from a multi-institutional database of patients who underwent this surgery between 2003 and 2023. The results showed that 10.3% of patients experienced unplanned readmissions, with the most common reasons being hyponatremia, CSF leak evaluation, headache/nausea, and epistaxis. The study also found that an increased number of chronic medical conditions and the need for a return to surgery were associated with a higher chance of unplanned readmission. The authors suggest strategies to mitigate these readmissions, such as fluid restriction and optimizing chronic medical conditions. [Extracted from the article]

This article, published in the Journal of Neurological Surgery, explores the factors that contribute to the recurrence of Cushing's disease (CD) after transsphenoidal surgery. The study analyzed data from the Registry of Adenomas of the Pituitary and Related Disorders (RAPID) database, which included 383 CD patients. The results showed that patients who experienced recurrence had a longer postoperative hospital stay, larger tumor volumes, and a higher rate of failed prior treatment. Younger age and the absence of cavernous sinus invasion were identified as potential protective factors against recurrence. The findings suggest that early detection and treatment of tumors may improve outcomes for CD patients. [Extracted from the article]

Crooke cell adenomas (CCAs) are a rare, aggressive subset of secretory pituitary corticotroph adenomas (sCTAs) found in 5%–10% of patients with Cushing disease. Multiple studies support worse outcomes in CCAs but are limited by small sample size and single-institution databases. We compared outcomes in CCA and sCTA using a multicenter, international retrospective database of high-volume skull base centers. Patients surgically treated for pituitary adenoma from January 2017 through December 2020 were included. Among 2826 patients from 12 international centers, 20 patients with CCA and 480 patients with sCTA were identified. No difference in baseline demographics, tumor characteristics, or postoperative complications was seen. Microsurgical approaches (60% CCA vs. 62.3% sCTA) were most common. Gross total resection was higher in CCA patients (100% vs. 83%, P = 0.05). Among patients with gross total resection according to intraoperative findings, fewer CCA patients had postoperative hormone normalization of pituitary function (50% vs. 77.8%, P < 0.01) and remission of hypersecretion by 3–6 months (75% vs. 84.3%, P < 0.01). This was the case despite CCA having better local control rates (100% vs. 96%, P < 0.01) and fewer patients with remnant on magnetic resonance imaging (0% vs. 7.2%, P < 0.01). A systematic literature review of 35 studies reporting on various treatment strategies reiterated the high rate of residual tumor, persistent hypercortisolism, and tumor-related mortality in CCA patients. This modern, multicenter series of patients with CCA reflects their poor prognosis and reduced postsurgical hormonal normalization. Further work is necessary to better understand the pathophysiology of CCA to devise more targeted treatment approaches. [ABSTRACT FROM AUTHOR]

Importance: Benchmarks aid in improve outcomes for surgical procedures. However, best achievable results that have been validated internationally for transsphenoidal surgery (TS) are not available. Objective: We aimed to establish standardized outcome benchmarks for TS of pituitary adenomas. Design: A total of 2685 transsphenoidal tumor resections from 9 expert centers in 3 continents were analyzed. Setting: Patients were risk stratified, and the median values of each center's outcomes were established. The benchmark was defined as the 75th percentile of all median values for a particular outcome. The postoperative benchmark outcomes included surgical factors, endocrinologyspecific values, and neurology-specific values. Results: Of 2685 patients, 1149 (42.8%) defined the low-risk benchmark cohort. Within these benchmark cases, 831 (72.3%) patients underwent microscopic TS, and 308 (26.8%) patients underwent endoscopic endonasal resection. Of all tumors, 799 (29.8%) cases invaded the cavernous sinus. The postoperative complication rate was 19.6% with mortality between 0.0% and 0.8%. Benchmark cutoffs were ≤2.9% for reoperation rate, ≤1.9% for cerebrospinal fluid leak requiring intervention, and ≤15.5% for transient diabetes insipidus. At 6 months, benchmark cutoffs were calculated as follows: readmission rate: ≤6.9%, new hypopituitarism ≤6.0%, and tumor remnant ≤19.2%. Conclusions: This analysis defines benchmark values for TS targeting morbidity and mortality and represents the best outcomes in the best patients in expert centers. These cutoffs can be used to assess different centers, patient populations, and novel surgical techniques. It should be noted that the benchmark values may influence each other and must be evaluated in their own context. [ABSTRACT FROM AUTHOR]

The economic potential for unconventional shale oil and gas production in the Silurian of the Berkine – Ghadames and Illizi basins (BGI) in south-eastern Algeria has been recently confirmed through exploration drilling. The aim of the present paper attempts a better understanding of the Intra-Tassilian depression within the entire Silurian of the Tassili n’Ajjer plateau. The continuous deposits of the Silurian are exposed at the southern margin of the prolific BGI basins, in the Tassili n’Ajjer plateau, offering the chance to understand the sedimentology, ichnology, and to present a detailed sequence stratigraphy framework for the region. The 410 m-thick clastic Silurian sedimentary strata are subdivided into three formations in the context of sequence stratigraphy, namely: (i) the Oued Imihrou Fm. (Llandoverian) overlain by (ii) the Atafaïtafa Fm. (late Llandoverian to Wenlockian), and (iii) the Oued Tifernine Fm. (late Wenlockian to Pridolian). These can be also distinguished across the entire investigated area and laterally traceable over kilometers. Clear cyclic stacking patterns are identified within the four studied sections showing progressively a general trend of thickening- and coarsening-upward, over a complete 2nd-order megasequence (SIL-1 MS). This transgressive-regressive succession suggests deltaic progradation, shallowing and basin infilling as evidenced by numerous diagnostic sedimentary features and trace fossils, largely from eastern-to western-Tassili plateau. Indeed, the wealth of outcrop data in the Silurian siliciclastic succession enables us to distinct thirteen facies (facies A-M), ranging from shallow-to marginal-marine facies, and in turn, grouped into six facies associations (FA1-FA6). The lowermost part of the succession, which is the most prolific sources of hydrocarbons in North Africa, consists of thick organic-rich graptolite-yielding black ‘hot’ shales and ‘lean’ shales with sparse bioturbation with small Thalassinoides belonging to the distal Cruziana ichnofacies. In contrast, the uppermost part of the Silurian deposits becomes progressively coarser and fluvial in response to the progradation of the North African Akakus deltaic system, during regional sea level fall and uplifting of the region. These progradational deposits exhibit well-preserved trace fossils with moderate to high degree of bioturbation, such as Skolithos or the so-called “Tigillites” pipe-rock, Cruziana isp., Rusophycus isp., Monocraterion isp., and Syringomorpha . The SIL-1 MS is bounded by a post-glacial latest Hirnantian unconformity on the basal (SB1), as confirmed by the moderately diverse early Silurian graptolite faunas, and by the Caledonian unconformity on the top (SB7). Each of the three formations of SIL-1 MS reveals two major 3rd-order progradational sequences, commonly delineated by discontinuity surfaces (in ascending order, SB1 to SB7), and in turn, these six sequences (i.e. Si-1 to Si-6) are subdivided into at least ten shorter-term cycles. The regional extent of each unconformity is directly linked to significant facies changes and to inflection points on the global sea level curve. [ABSTRACT FROM AUTHOR]