Caves and karst-like features in Proterozoic gneiss and Cambrian granite, southern and central Sri Lanka: An introduction

There has been little study of the geology and geomorphologyof the caves and karst-like features developed in the Proterozoicgneiss and Cambrian granite of Sri Lanka. This lack of studyis surprising given that caves and rockshelters in these rockscontain significant archaeological and cultural sites. Caves andkarren, both mimicking those developed in carbonate rocks,have formed both in gneiss, which is the dominant rock type ofthe Proterozoic crust of the island and in granite. In addition tooverhangs, boulder caves, soil pipes and tectonic caves, tunnelcaves, arch caves and block breakdown caves of significant sizeare developed in siliceous rocks in Sri Lanka. While metamorphoseddolomites are interfoliated within the gneissic suite,simple removal of carbonate by solution from within the surroundingrock cannot account for all or most of the speleogenesisobserved. While spalling and breakdown are responsiblefor cave enlargement cave initiation is probably due to eitherphreatic solution of silicates and/or phantom rock processes.Speleothems and cave minerals including silicates, phosphates,gypsum, carbonates and niter are found in the caves. Activesilicate speleothems are not restricted to joints and fissures andsuggest that solution of silicates is currently occurring withinthe body of the rock in the vadose zone. While guano is thelikely source of the phosphate, sulfate and nitrate, the sourceof the calcium in the carbonates remains unclear. Caves in theintrusive and metamorphic rocks of Sri Lanka are enigmatic.They are unexpectedly similar in appearance to their carbonatekarst counterparts. Continuing research will allow them tohold a mirror to our understanding of speleogenesis, mineralizationand sedimentation in carbonate karst caves

Maternal clinical predictors of preterm birth in twin pregnancies: A systematic review involving 2,930,958 twin pregnancies

Supplementary material related to this article can be found, in the online version, at doi:https://doi.org/10.1016/j. ejogrb.2018.09.025

Listening to patients, for the patients: The COVAD Study-Vision, organizational structure, and challenges

Background: The pandemic presented unique challenges for individuals with autoimmune and rheumatic diseases (AIRDs) due to their underlying condition, the effects of immunosuppressive treatments, and increased vaccine hesitancy. Objectives: The COVID-19 vaccination in autoimmune diseases (COVAD) study, a series of ongoing, patient self-reported surveys were conceived with the vision of being a unique tool to gather patient perspectives on AIRDs. It involved a multinational, multicenter collaborative effort amidst a global lockdown. Methods: Leveraging social media as a research tool, COVAD collected data using validated patient-reported outcomes (PROs). The study, comprising a core team, steering committee, and global collaborators, facilitated data collection and analysis. A pilot-tested, validated survey, featuring questions regarding COVID-19 infection, vaccination and outcomes, patient demographics, and PROs was circulated to patients with AIRDs and healthy controls (HCs). Discussion: We present the challenges encountered during this international collaborative project, including coordination, data management, funding constraints, language barriers, and authorship concerns, while highlighting the measures taken to address them. Conclusion: Collaborative virtual models offer a dynamic new frontier in medical research and are vital to studying rare diseases. The COVAD study demonstrates the potential of online platforms for conducting large-scale, patient-focused research and underscores the importance of integrating patient perspective into clinical care. Care of patients is our central motivation, and it is essential to recognize their voices as equal stakeholders and valued partners in the study of the conditions that affect them