Widespread elevated concentrations of gaseous elemental mercury in Guanajuato, Mexico, centuries after historical silver refining by mercury amalgamation.

Silver (Ag) production in Hispanic America between the 16th and 19th centuries is thought to be one of the largest sources of anthropogenic mercury (Hg) emissions in history. Recent reviews of the chemistry behind the patio process, which used Hg amalgamation to extract Ag from ore, reveal that a large amount of the Hg may not have been immediately released to the atmosphere; instead, it may have been captured in the form of calomel (Hg2Cl2, in which Hg exists as monovalent HgI) and remained in the local environment. Here we show that Hg used in the patio process centuries ago in the Guanajuato Mining District of Mexico continues to elevate present-day concentrations of gaseous elemental mercury (GEM) throughout the region. In the ground-level air, GEM ranged from 8 to 454 ng m-3, exceeding the Northern Hemispheric average (~1.4 ng m-3) by up to two orders of magnitude. Much higher concentrations, up to 44,700 ng m-3, were found in the interstitial air of reprocessed mineral wastes, sediment, and soil. These highly elevated present-day GEM values are due, at least in part, to the disproportionation of legacy calomel, as supported by the presence of HgI in the reprocessed wastes and by the GEM release pattern from calomel disproportionation. Our results imply that the contribution of historical Ag refining to atmospheric Hg emissions must be re-evaluated to account for calomel and its subsequent disproportionation and releases of GEM to the present-day.

Effect of Egg Weight and Patio Strategies on Hatching Traits and Subsequent Performance of the Broilers

Objectives of the present study were to assess the hatchery based interventions and their impact on hatching traits and subsequent performance of broilers. In total, 3000 eggs of Hubbard broiler breeders were equally divided into Small (50-55 g), Medium (56-61 g) and Large (62-70 g) eggs. The eggs from each category were distributed into 20 trays each containing 50 eggs. Each tray was considered as a replicate. At the end of the 18th day of incubation, the eggs of each weight category were divided into four different patio strategies i.e. P0, P3, P5 and P7 where feed and water were provided to the chicks for 0, 3, 5 and 7 days in the hatcher followed by conventional rearing. Data were collected for hatch window, hatching traits, growth, physical asymmetry, welfare and blood profile in broilers. Statistical analysis showed that the smaller eggs had significantly (P 0.05) shorter hatch window compared to larger and medium eggs. Hatching traits were significantly (p 0.05) better in medium eggs but the embryonic mortalities did not differ (p>0.05). The post-hatch performance was significantly (p 0.05) better in P3 birds from medium eggs. Physical asymmetry and scores of feather and gait were not affected by both treatments (p>0.05). Blood profile was also significantly (p 0.05) better in P3 birds from medium-size eggs. It was recommended that the eggs of 56-61g should be selected for better hatchability and the chicks should be provided with feed and water within the hatcher for at-least three days for optimum performance on rearing facility.(AU)

Effect of Egg Weight and Patio Strategies on Hatching Traits and Subsequent Performance of the Broilers

Objectives of the present study were to assess the hatchery based interventions and their impact on hatching traits and subsequent performance of broilers. In total, 3000 eggs of Hubbard broiler breeders were equally divided into Small (50-55 g), Medium (56-61 g) and Large (62-70 g) eggs. The eggs from each category were distributed into 20 trays each containing 50 eggs. Each tray was considered as a replicate. At the end of the 18th day of incubation, the eggs of each weight category were divided into four different patio strategies i.e. P0, P3, P5 and P7 where feed and water were provided to the chicks for 0, 3, 5 and 7 days in the hatcher followed by conventional rearing. Data were collected for hatch window, hatching traits, growth, physical asymmetry, welfare and blood profile in broilers. Statistical analysis showed that the smaller eggs had significantly (P 0.05) shorter hatch window compared to larger and medium eggs. Hatching traits were significantly (p 0.05) better in medium eggs but the embryonic mortalities did not differ (p>0.05). The post-hatch performance was significantly (p 0.05) better in P3 birds from medium eggs. Physical asymmetry and scores of feather and gait were not affected by both treatments (p>0.05). Blood profile was also significantly (p 0.05) better in P3 birds from medium-size eggs. It was recommended that the eggs of 56-61g should be selected for better hatchability and the chicks should be provided with feed and water within the hatcher for at-least three days for optimum performance on rearing facility.

Influência do processamento por via úmida e tipos de secagem sobre a composição, físico química e química do café (Coffea arabica L) / Influence of the wet processing and drying types on chemical and physicochemical composition of coffee (Coffea arabica L. )

O café (Coffea arabica L.) é um importante produto de exportação brasileira, por fazer parte do hábito alimentar da população de diversos países. Sua produção vem passando por transformações tecnológicas que têm como objetivo agregar valores qualitativos ao produto destinado tanto para mercado interno como externo. A exportação do café e de produtos alimentícios deve se adequar aos programas de qualidade estabelecidos por acordos políticos internacionais. Assim sendo, objetivou-se, nesse estudo, verificar a influência do método de preparo via úmida com tipos distintos de secagens, na obtenção do café cereja descascado, sobre a composição, físico-química e química do café. Houve influência da forma, preparo e tipo de secagem sobre as principais características estudadas. O café cereja descascado apresentou diferenças nos principais indicadores químicos físico-químicos e com uma superioridade para esse método de preparo com secagem exclusiva no terreiro, em diversos aspectos. Houve redução na condutividade elétrica, lixiviação de potássio e aumento da atividade da polifenoloxidase.

Coffee (Coffea arabica L.) is an important Brazilian export product, being part of the eating habit in several countries. Its production has experienced technological transformations, with the aim at adding quality values to the product destined to internal as well as to external market. The export of coffee and food products must adjust to the quality programs established by international political agreements. In this context, this work was carried out to verify the influence of the wet processing using different drying types on the obtentainment of the husked coffee cherry on the chemical and physicochemical composition of the coffee. There was influence of the preparation and the drying type methods on the main studied characteristics. The peeled red cherry coffee presented differences in the main chemical and physicochemical indicators, with a superiority in the preparation method with exclusive drying on the patio, in several aspects. Reduction in the electric conductivity and potassium leaching was observed as well as increase in the polyphenoloxidase activity.