The cash crop revolution, colonialism and economic reorganization in Africa

In the 19th and 20th centuries, African economies experienced a significant structural transformation from the slave trades to commercial agriculture. We analyze the long-run impact of this economic transition focusing on the dynamic effects of: shifting geographic fundamentals to favor agroclimatic suitability for cash crops; infrastructural investments to reduce trade costs; and external forward production linkages. Using agro-climatic suitability scores and historical data on the source location of more than 95 percent of all exports across 38 African states, we assess the consequences of these changes on economic reorganization across the continent. We find that colonial cash crop production had positive long-run effects on urbanization, road infrastructure, nighttime luminosity, and household wealth. These effects rival or surpass other geographic and historical forces. Exploring causal mechanisms, we show that path dependence due to colonial infrastructure investments is the more important channel than continued advantages in agricultural productivity. However, these agglomerating effects were highly localized; we find limited evidence that commercial agriculture spurred broader regional growth, in contrast to other cash crop regions around the world. If anything, we observe in Africa the economic gains accruing to cash crop zones came at the expense of nearby areas, which are worse off today than expected based on underlying characteristics. Overall, our analysis has important implications for the debate on the long-run effects of colonialism on development in the region. Rather than offsetting negative institutional effects, subnational extractive processes may have reinforced them by sowing economic and social inequalities

Comparison of established and emerging biodosimetry assays

Rapid biodosimetry tools are required to assist with triage in the case of a large-scale radiation incident. Here, we aimed to determine the dose-assessment accuracy of the well-established dicentric chromosome assay (DCA) and cytokinesis-block micronucleus assay (CBMN) in comparison to the emerging γ-H2AX foci and gene expression assays for triage mode biodosimetry and radiation injury assessment. Coded blood samples exposed to 10 X-ray doses (240 kVp, 1 Gy/min) of up to 6.4 Gy were sent to participants for dose estimation. Report times were documented for each laboratory and assay. The mean absolute difference (MAD) of estimated doses relative to the true doses was calculated. We also merged doses into binary dose categories of clinical relevance and examined accuracy, sensitivity and specificity of the assays. Dose estimates were reported by the first laboratories within 0.3-0.4 days of receipt of samples for the γ-H2AX and gene expression assays compared to 2.4 and 4 days for the DCA and CBMN assays, respectively. Irrespective of the assay we found a 2.5-4-fold variation of interlaboratory accuracy per assay and lowest MAD values for the DCA assay (0.16 Gy) followed by CBMN (0.34 Gy), gene expression (0.34 Gy) and γ-H2AX (0.45 Gy) foci assay. Binary categories of dose estimates could be discriminated with equal efficiency for all assays, but at doses ≥1.5 Gy a 10% decrease in efficiency was observed for the foci assay, which was still comparable to the CBMN assay. In conclusion, the DCA has been confirmed as the gold standard biodosimetry method, but in situations where speed and throughput are more important than ultimate accuracy, the emerging rapid molecular assays have the potential to become useful triage tools

IMPACTO DA HIPERGLICEMIA E DO POLIMORFISMO GENÉTICO EM PACIENTE DIABETICOS ACOMETIDOS PELA COVID-19.

The world is facing one of the worst pandemics today, where around 4.7 million people lost their lives due to COVID-19. However, people with chronic diseases are more susceptible to worsening their clinical condition when affected by the new coronavirus. Patients with Diabetes mellitus (DM) promote a chronic inflammatory state and when affected by COVID-19, they are more prone to changes in the innate immune system, which can even trigger a storm of cytokines that is harmful to the host. Our objective was to address the impact of genetic polymorphism involving ACE 2 and clinical severity in people with hyperglycemia affected by COVID-19. This is a literature review with a qualitative approach, carried out on the PUBMED portal. The following search string was used: Polymorphism genetic, Diabetes, COVID-19, Hyperglycemia and Critical Care. Regarding polymorphism, it was observed that some variations may play a role in influencing the entry of the virus into the host body and others may be a useful tool to predict disease development and treatment against COVID-19.O mundo enfrenta uma das piores pandemias na atualidade, onde cerca de 4,7 milhões de pessoas perderam suas vidas devido a COVID-19. No entanto as pessoas portadoras de doenças crônicas estão mais suscetíveis ao agravamento de seu quadro clínico quando acometidas pelo novo coronavírus. Os portadores de Diabetes mellitus (DM) promovem um estado crônico inflamatório e quando acometidos pela COVID-19 ficam mais propensos a alterações no sistema imunológico inato, podendo ainda ativar uma tempestade de citocinas deletéria ao hospedeiro. Nosso objetivo foi abordar o impacto do polimorfismo genético envolvendo ACE 2 e a gravidade clínica em pessoas com hiperglicemia acometidas pela COVID-19. Trata-se de uma revisão de literatura de abordagem qualitativa, realizada no portal PUBMED. Utilizou-se a seguinte string de pesquisa: Polymorphism genetic, Diabetes, COVID-19, Hyperglycemia e Critical Care. Em relação ao polimorfismo observou-se que algumas variações podem desempenhar um papel na influência da entrada do vírus no corpo do hospedeiro e outros podem ser uma ferramenta útil para prever o desenvolvimento da doença e tratamento contra o COVID-19

Hyperpycnal flow behavior generated by physical simulations : a comparison between confined and unconfined flows

O estudo de fluxos hiperpicnais é extremamente importante dentro da indústria do petróleo, pois depósitos gerados por tais fluxos podem se tornar potenciais reservatórios de hidrocarbonetos. Uma das maneiras de entender esses processos sedimentares em ambiente marinho é através de experimentos em laboratórios (modelagem física), onde se controla os parâmetros envolvidos de maneira que reproduzam mais precisamente o fenômeno natural. Usando essa técnica de estudo, este trabalho visou comparar o comportamento de um fluxo hiperpicnal em duas situações distintas, ou seja, confinado em um canal subaquoso e fora do mesmo (não confinado). Buscou-se estabelecer as diferenças de hidrodinâmica e suas implicações no transporte e na deposição de sedimentos, durante um curto intervalo de tempo, de um experimento físico tridimensional de longa duração. Através da análise de imagens foi possível estabelecer correlações de velocidade, geometria e acelerações entre as duas situações do fluxo. Os resultados mostram que o fluxo, ao atingir a zona confinada, acelera espacialmente e localmente, modificando suas características geométricas (alongamento da região frontal) em relação ao fluxo que escoa fora da zona confinada. Nos ambientes naturais, esse tipo de fenômeno localizado e curto pode ocorrer por longas distâncias, com uma duração maior. Este confinamento com duração longa poderia proporcionar um aumento na velocidade do fluxo, propiciando a ocorrência maior de processos erosivos em relação a processos deposicionais.The study of hyperpycnal flows (a type of sediment gravity flow) is extremely important in the petroleum industry, since deposits generated by such flows become potential hydrocarbon reservoirs. In order to understand these sedimentary processes in marine environment, laboratory experiments (physical modeling) with controlled input parameters are being performed more accurately to reproduce this natural complex phenomenon. Using this power tool, this work aims to compare the behavior of a hyperpycnal flow in two different situations, i.e., confined and unconfined flow in a subaqueous channel. We sought to establish the hydrodynamic differences and their implications in the transport and deposition of sediments during a short instant of time from a tridimensional physical experiment of long duration. Through the analysis of images was possible to establish correlations of velocity, acceleration and geometry between the two flow situations. The results show that the hyperpycnal flow generated at the beginning of the experiment accelerates both temporally and spatially as well as modifies its geometrical characteristics (elongation of the frontal region). In natural environments, such a locally and short phenomenon can occur through large distance and duration, this can afford an increase in flow velocity through the way, providing a greater occurrence of erosive process compared with depositional processes

Clinical and Genetic Tumor Characteristics of Responding and Non-Responding Patients to PD-1 Inhibition in Hepatocellular Carcinoma.

Immune checkpoint inhibitors (ICIs) belong to the therapeutic armamentarium in advanced hepatocellular carcinoma (HCC). However, only a minority of patients benefit from immunotherapy. Therefore, we aimed to identify indicators of therapy response. This multicenter analysis included 99 HCC patients. Progression-free (PFS) and overall survival (OS) were studied by Kaplan-Meier analyses for clinical parameters using weighted log-rank testing. Next-generation sequencing (NGS) was performed in a subset of 15 patients. The objective response (OR) rate was 19% median OS (mOS)16.7 months. Forty-one percent reached a PFS > 6 months; these patients had a significantly longer mOS (32.0 vs. 8.5 months). Child-Pugh (CP) A and B patients showed a mOS of 22.1 and 12.1 months, respectively. Ten of thirty CP-B patients reached PFS > 6 months, including 3 patients with an OR. Tumor mutational burden (TMB) could not predict responders. Of note, antibiotic treatment within 30 days around ICI initiation was associated with significantly shorter mOS (8.5 vs. 17.4 months). Taken together, this study shows favorable outcomes for OS with low AFP, OR, and PFS > 6 months. No specific genetic pattern, including TMB, could identify responders. Antibiotics around treatment initiation were associated with worse outcome, suggesting an influence of the host microbiome on therapy success

Dose-dependent long-term effects of a single radiation event on behaviour and glial cells

Purpose The increasing use of low-dose ionizing radiation in medicine requires a systematic study of its long-term effects on the brain, behaviour and its possible association with neurodegenerative disease vulnerability. Therefore, we analysed the long-term effects of a single low-dose irradiation exposure at 10 weeks of age compared to medium and higher doses on locomotor, emotion-related and sensorimotor behaviour in mice as well as on hippocampal glial cell populations. Materials and methods We determined the influence of radiation dose (0, 0.063, 0.125 or 0.5 Gy), time post-irradiation (4, 12 and 18 months p.i.), sex and genotype (wild type versus mice with Ercc2 DNA repair gene point mutation) on behaviour. Results The high dose (0.5 Gy) had early-onset adverse effects at 4 months p.i. on sensorimotor recruitment and late-onset negative locomotor effects at 12 and 18 months p.i. Notably, the low dose (0.063 Gy) produced no early effects but subtle late-onset (18 months) protective effects on sensorimotor recruitment and exploratory behaviour. Quantification and morphological characterization of the microglial and the astrocytic cells of the dentate gyrus 24 months p.i. indicated heightened immune activity after high dose irradiation (0.125 and 0.5 Gy) while conversely, low dose (0.063 Gy) induced more neuroprotective features. Conclusion This is one of the first studies demonstrating such long-term and late-onset effects on brain and behaviour after a single radiation event in adulthood