11 research outputs found
Petrogenesis and tectonic of the Urucum granitic suite, Rio Doce Valley (Minas Gerais - Brazil): an example of syn to late collisional peraluminous magmatism associated with high-angle transcurrent shear zone
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
Effect of rapid chilling and pelvic suspension on meat quality of Longissimus dorsi muscle of lamb [Hi{dotless}zli{dotless} so?utma ve pelvik asi{dotless}lmani{dotless}n kuzulara ait longissimus dorsi kasi{dotless}ndaki et kalitesi ĂĽzerine etkisi]
The objective of this study was to examine the effect of rapid (RC) and conventional (CC) chilling with achilles (AS) and pelvic (PS) suspension on the meat quality of M. Longissimus dorsi. Twenty lamb carcasses were randomly allocated immediately prior to slaughter to the two experimental groups which were subjected to four different treatments. In the first group, carcasses were suspended from the Achilles tendon. Right sides (RC/AS; n=10) were rapidly chilled, while the left sides (CC/AS; n=10) were conventionally chilled. In the second group, the carcasses were re-hanged from the pelvic bone. Right sides (RC/PS; n=10) were rapidly chilled whilst the left sides (CC/PS; n=10) were conventionally chilled. Meat quality was evaluated by measuring the water holding capacity (WHC), cooking loss (CL), surface colour and shear force (SF). As a result, CC accelerated the rate of pH decline while RC increased the temperature decline. RC reduced CL and WHC values. PS had no impact on WHC, CL and color of steaks, but decreased the SF values on the 7th days of post-mortem. In conclusion; PS is a useful method for improving tenderness during storage period and the disadvantageous effect of RC on SF could be equalized by using PS
Simultaneous determination of clobutinol hydrochloride and doxylamine succinate from syrups by RP HPLC using a new stationary phase containing embedded urea polar groups
A new, simple, fast, reproducible and sensitive reversed phase HPLC method, using a new stationary phase containing embedded urea polar groups, has been developed and validated for the simultaneous determination of clobutinol hydrochloride (CLO) and doxylamine succinate (DOX) in syrups. The determination was carried out on a C8 urea column (125 mm x 3.9 mm i.d., 5 µm particle size) synthetized at the Liquid Chomatography Laboratory (LabCrom) of the Chemistry Institute of Unicamp. The mobile phase consisted of a mixture of acetonitrile:methanol:phosphate buffer (pH 2.5) in the gradient mode. The diode array detector (DAD) was operated at 230 nm for CLO and 262 nm for DOX. The method showed adequate precision, with relative standard deviations (RSD) less than 1%. The presence of the excipients did not interfere in the results of the analysis. Accuracy was determined by adding standards of the drugs to a placebo and good recovery values were obtained. The analytical curves were linear (r² 0.9999 for CLO and 0.9998 for DOX) over a wide concentration range (2.4-336 µg mL-1 for CLO and 2.3-63 µg mL-1 for DOX). The solutions were stable for at least 72 hours at room temperature. The criteria for validation using the ICH guidelines were fulfilled.<br>Um novo mĂ©todo simples, fácil e reprodutĂvel, de fase reversa para CLAE, usando uma fase estacionária contendo um grupo polar, urĂ©ia, embutido, foi desenvolvido e validado para determinação simultânea de cloridrato de clobutinol (CLO) e succinato de doxilamina (DOX) em xarope. A determinação foi realizada em uma coluna C8 urĂ©ia (125 mm x 3,9 mm d.i., 5 µm tamanho de partĂcula) sintetizada em nosso laboratĂłrio (LabCrom). A fase mĂłvel consistiu de mistura de acetonitrila:metanol:tampĂŁo fosfato pH 2,5, em eluição por gradiente. O detector por arranjos de diodo (DAD) foi utilizado a 230 nm para CLO e a 262 nm para DOX. O mĂ©todo apresentou precisĂŁo adequada, com desvio padrĂŁo relativo menor que 1%. A presença de excipientes nĂŁo interferiu nos resultados obtidos. A exatidĂŁo foi realizada pela adição dos padrões dos fármacos ao placebo e valores de recuperação aceitáveis foram obtidos. As curvas analĂticas mostraram-se lineares (r² 0,9999 para CLO e 0,9998 para DOX) em uma ampla faixa de concentração (2,4-336 µg mL-1 para CLO e 2,3-63 µg mL-1 para DOX). A solução padrĂŁo foi estável por 72 horas a temperatura ambiente. Os parâmetros de validação foram realizados conforme o guia ICH