Freeze-drying modeling and monitoring using a new neuro-evolutive technique

This paper is focused on the design of a black-box model for the process of freeze-drying of pharmaceuticals. A new methodology based on a self-adaptive differential evolution scheme is combined with a back-propagation algorithm, as local search method, for the simultaneous structural and parametric optimization of the model represented by a neural network. Using the model of the freeze-drying process, both the temperature and the residual ice content in the product vs. time can be determine off-line, given the values of the operating conditions (the temperature of the heating shelf and the pressure in the drying chamber). This makes possible to understand if the maximum temperature allowed by the product is trespassed and when the sublimation drying is complete, thus providing a valuable tool for recipe design and optimization. Besides, the black box model can be applied to monitor the freeze-drying process: in this case, the measurement of product temperature is used as input variable of the neural network in order to provide in-line estimation of the state of the product (temperature and residual amount of ice). Various examples are presented and discussed, thus pointing out the strength of the too

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

New approaches in assessment of tsunami deposits in Dalaman (SW Turkey)

Some earthquakes in the Eastern Mediterranean are tsunamigenic, and some of their tsunamis affected the coastal area of the Gulf of Fethiye, SW Turkey. Recent trenching surveys on the low-lying coastal areas of Dalaman delta beach across the Rhodes Pass revealed three probable tsunami impacts as a result of the historical earthquakes of 1303, 1481, and 1741. Yet there have been relatively few studies of the processes associated with tsunami sediment transport, their deposition, and nature in geological record. In addition to the interpretation of sedimentary features, accurate palaeo-environmental assessments might be possible by distinctive biogeochemical researches on marine-sourced organic matters, geochemical properties, quantitative amounts of marine biomarkers, and deterministic ratios. The identification of major lipid biomarkers (fatty acids and sterols) in the samples recovered from the sidewalls of the studied trench, for example, indicated biogenic contributions due to the presence of phytoplankton, zooplankton, bacteria, and dinoflagellates. Quantitative estimation of biomarkers and deterministic ratios also indicated some evidences for marine-sourced organic matters, implying that biomarkers can be used to answer the open questions in tsunami and palaeo-tsunami researches

Black Sea Tsunamis and Paleotsunami Studies on the Thrace Coasts of Turkey

It is identified that 23 moderate tsunamis hit the Black Sea's coasts during the last 2000 years. Some of these tsunamis had been catastrophic at some vulnerable spots of the coast, flooding coastal areas and drowning a few thousand people in towns and villages; such as the ones in 544/545 and 1598. Tsunamis may leave their fingerprints typically in low-energy depositional environments such as coastal wetlands, lagoons and places protected from the sea by sandy barriers. Such places protect tsunami deposits from post-depositional erosion. The topographic conditions of the Black Sea coastline of Turkey are not favourable in preservation of marine flood deposits. A few low lying beaches or marsh-filled depositional sedimentary basins on the Thrace coasts may have geomorphologic potential, even usually intercalated with fluvial effects of nearby creeks, to record and keep the clues of historical tsunami impacts. Yet there have been relatively few studies of the processes associated with tsunami sediment transport, their deposition and nature; the present study attempts to understand if a coarse grained sedimentary unit mixed with marine shell fragments observed in a trench in Kiyikoy could have been related to a historical tsunami. The soil samples were tested for their particle characterization, micro-fossil contents, standard sediment chemistry and biochemical conditions. Even though some effects of a marine intrusion were observed, the results are open to debate. For more meaningful regional explanations and to give way to numerical modelling which make the main tasks for tsunami hunting in the Black Sea, similar studies throughout the basin are needed