The Type 2 Iodothyronine Deiodinase is Essential for Adaptive Thermogenesis in Brown Adipose Tissue

Type 2 iodothyronine deiodinase (D2) is a selenoenzyme, the product of the recently cloned cAMP-dependent Dio2 gene, which increases 10- to 50-fold during cold stress only in brown adipose tissue (BAT). Here we report that despite a normal plasma 3,5,3′-triiodothyronine (T3) concentration, cold-exposed mice with targeted disruption of the Dio2 gene (Dio2–/–) become hypothermic due to impaired BAT thermogenesis and survive by compensatory shivering with consequent acute weight loss. This occurs despite normal basal mitochondrial uncoupling protein 1 (UCP1) concentration. In Dio2–/– brown adipocytes, the acute norepinephrine-, CL316,243-, or forskolin-induced increases in lipolysis, UCP1 mRNA, and O2 consumption are all reduced due to impaired cAMP generation. These hypothyroid-like abnormalities are completely reversed by a single injection of T3 14 hours earlier. Recent studies suggest that UCP1 is primarily dependent on thyroid hormone receptor β (TRβ) while the normal sympathetic response of brown adipocytes requires TRα. Intracellularly generated T3 may be required to saturate the TRα, which has an approximately fourfold lower T3-binding affinity than does TRβ. Thus, D2 is an essential component in the thyroid-sympathetic synergism required for thermal homeostasis in small mammals

Variability in herbivore-induced defence signalling across different maize genotypes impacts significantly on natural enemy foraging behaviour

‘Smart’ plants that release volatile defence compounds in response to pest damage, and which recruit beneficial natural enemies, offer an opportunity for exploiting biological control in future crop protection strategies. Using six maize genotypes, Zapalote Chico (‘landrace’), Mirt2A, Sintético Spodoptera (SS), L3, and two commercial hybrids BRS 4103 and BRS 1040, the aim of this work was to evaluate maize responses to larval damage from the fall armyworm Spodoptera frugiperda, a major maize pest in Brazil, and the ability of the egg parasitoid Telenomus remus to respond to HIPVs induced by S. frugiperda damage. Y-tube olfactometer bioassays with T. remus showed preferential responses to the S. frugiperda-induced volatiles of SS and BRS 4103 compared to constitutive volatiles of the same genotypes, but to none of the other genotypes tested. Chemical analysis of maize volatile extracts showed that SS produced more volatile compounds in response to S. frugiperda damage, followed by BRS 4103. In addition, higher levels of mono, homo-, or sesquiterpenes, together with green leaf volatiles (GLVs) were the most attractive blend for T. remus; however, there was no attraction when only GLVs were produced in higher levels. In summary, these results show that volatile defence signalling produced by maize plants due to S. frugiperda damage varies significantly depending on maize genotype and this variability influences T. remus foraging behaviour

The first 80 days of the COVID-19 pandemic in the city of Belo Horizonte : from containment to reopening.

Este artigo examina o contexto e as implica??es da pandemia por Covid-19 na cidade de Belo Horizonte (BH) nos primeiros 80 dias da doen?a. Utilizamos um recorte anal?tico descritivo para mensurar a evolu??o dos casos, o excesso de ?bitos, a taxa de transmissibilidade do v?rus e a press?o da doen?a sobre o sistema de sa?de de BH e regi?o, atrav?s da taxa de ocupa??o hospitalar nos leitos p?blicos. Al?m disso, identificamos as principais pol?ticas de conten??o adotadas pelas autoridades locais, bem como as implica??es da redu??o do distanciamento social. Nossos resultados demonstram que o Sistema ?nico de Sa?de (SUS), bem gerido, ? fundamental para o enfrentamento da pandemia e a mitiga??o de suas consequ?ncias para a popula??o. O processo de flexibiliza??o que se inicia tem imposto novos desafios que requerer?o monitoramento atento das autoridades e da sociedade.The paper examines the implications of Co vid-19 pandemic for the city of Belo Horizonte (BH), during the fi rst 80 days of the disease. We use a descriptive-analytical approach to estimate the growth of Covid-19 cases over time, the excess of deaths, the virus? rate of transmissibility, and the consequent burden on the municipal the health system, measured by the rate of occupancy of public hospital beds. Also, we identify the main containment policies adopted by local authorities, and the implications of reopen ing measures and the following reduction of social distancing. Our fi ndings reveal that a well-managed Unifi ed Health System (SUS) is paramount to effectively tackle the pan demic and its consequences for the population. The reopening process has imposed new challenges that will require close monitoring by the authorities and by the Society

Compostos não voláteis em cafés da região sul de minas submetidos a diferentes pontos de torração Non-volatile compounds in coffee from the south of Minas Gerais state region submitted to different roasting degrees

O processo de torração do café induz alterações físicas, químicas e sensoriais na matéria-prima, cuja intensidade e tipo dependem, principalmente, da composição química dos grãos e do tempo e temperatura utilizados na execução do mesmo. Este processo promove a degradação, formação e volatilização de vários compostos. Comercialmente, existem cafés torrados e moídos em diferentes pontos de torração, os quais originam bebidas com diferentes propriedades sensoriais e nutricionais. Os compostos trigonelina, ácidos clorogênicos e cafeína interferem no sabor e aroma do café. A trigonelina e os ácidos clorogênicos vêm sendo estudados também quanto ao aspecto nutricional, uma vez que esses compostos possuem ação benéfica à saúde. Esses compostos são solúveis em água quente, portanto, estarão presentes na bebida em função da sua estabilidade no processo de torração. Conduziu-se este trabalho, com o objetivo de avaliar as concentrações dos compostos trigonelina, ácidos clorogênicos e cafeína em cafés da espécie Coffea arabica L. classificados como bebida mole, dura e rio submetidos a três pontos de torração: claro, médio e escuro. As torrações mais acentuadas promoveram uma maior degradação de trigonelina e ácido 5-cafeoilquínico, enquanto que a torração clara promoveu degradação apenas para o ácido clorogênico, não interferindo nas concentrações de trigonelina. A degradação da cafeína não ocorreu em nenhum ponto de torração.<br>The roasting process of coffee induces sensorial, chemical and physical alterations in the raw material. The type and intensity of the process depend mainly on the chemical composition of the grains and on the time and temperature used. This process promotes the degradation, formation and volatilisation of several compounds. There are roast and ground coffees submitted to different roasting conditions available in the market, which give origin to beverages with different sensorial and nutritional properties. The compounds trigonelline, chlorogenic acids and caffeine interfere with the flavor of the coffee. The trigonelline and the chlorogenic acids were studied considering their nutritional aspect as well, since these compounds and"or their degradation products have a beneficial action to our health. These compounds are soluble in hot water therefore they will be present in the beverage depending on their stability through the roasting process. The aim of this work was to asses the concentrations of trigonelline, chlorogenic acids and caffeine in coffees of the species Coffea arabica, classified as soft, hard, and rio which were submitted to three roasting degrees: light, medium, and dark. The most intense roasting process generated a greater degradation of trigonelline and 5-caffeoilquinic (5-CQA) while the light roasting caused degradation just of the chlorogenic acid, not interfering with the trigonelline concentrations. Caffeine was not degraded at any roasting degree