Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters











Language
Publication year range
1.
Nature ; 623(7989): 938-941, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37783227

ABSTRACT

Large constellations of bright artificial satellites in low Earth orbit pose significant challenges to ground-based astronomy1. Current orbiting constellation satellites have brightnesses between apparent magnitudes 4 and 6, whereas in the near-infrared Ks band, they can reach magnitude 2 (ref. 2). Satellite operators, astronomers and other users of the night sky are working on brightness mitigation strategies3,4. Radio emissions induce further potential risk to ground-based radio telescopes that also need to be evaluated. Here we report the outcome of an international optical observation campaign of a prototype constellation satellite, AST SpaceMobile's BlueWalker 3. BlueWalker 3 features a 64.3 m2 phased-array antenna as well as a launch vehicle adaptor (LVA)5. The peak brightness of the satellite reached an apparent magnitude of 0.4. This made the new satellite one of the brightest objects in the night sky. Additionally, the LVA reached an apparent V-band magnitude of 5.5, four times brighter than the current International Astronomical Union recommendation of magnitude 7 (refs. 3,6); it jettisoned on 10 November 2022 (Universal Time), and its orbital ephemeris was not publicly released until 4 days later. The expected build-out of constellations with hundreds of thousands of new bright objects1 will make active satellite tracking and avoidance strategies a necessity for ground-based telescopes.

2.
Acta sci., Anim. sci ; 41: 44066-44066, 2019. tab
Article in English | VETINDEX | ID: biblio-1459842

ABSTRACT

We evaluated meat quality and color of breast during storage in ducks fed diet supplemented with different forms of Houttuynia cordata (HC) with fermented red koji (FRK). In total, 240 one-day-old Pekin ducks (160 males and 80 females) were allocated to four diet treatments (control, 1% HC powder mixed with FRK, pelleted 1% HC with FRK, and coated pellets of 1% HC with FRK). At days 3 and 7 of storage, pH values were slightly influenced (p < 0.05) by different forms of HC with FRK, but was no influence at day 0 of storage day. Diet treatments with different forms of HC and FRK had an effect (p < 0.05) on TBARS values at 0, 3, and 7 days of storage and DPPH radical-scavenging activity at 0 days of storage, except for cooking loss. Overall, in breast meat of ducks, L* values at day 3 of storage and a* values at day 0 of storage were significantly influenced (p < 0.05) by treatments with different forms of HC and FRK. In conclusion, using either 1% HC and FRK pellets or pellets coated with HC and FRK at 1% resulted in a decrease in TBARS values and an increase in DPPH radical-scavenging activity during storage.


Subject(s)
Animals , Meat , Meat/analysis , Houttuynia , Ducks/metabolism , Infant Nutritional Physiological Phenomena
3.
Acta Sci. Anim. Sci. ; 41: e44066-e44066, jan. 2019. tab
Article in English | VETINDEX | ID: vti-18729

ABSTRACT

We evaluated meat quality and color of breast during storage in ducks fed diet supplemented with different forms of Houttuynia cordata (HC) with fermented red koji (FRK). In total, 240 one-day-old Pekin ducks (160 males and 80 females) were allocated to four diet treatments (control, 1% HC powder mixed with FRK, pelleted 1% HC with FRK, and coated pellets of 1% HC with FRK). At days 3 and 7 of storage, pH values were slightly influenced (p < 0.05) by different forms of HC with FRK, but was no influence at day 0 of storage day. Diet treatments with different forms of HC and FRK had an effect (p < 0.05) on TBARS values at 0, 3, and 7 days of storage and DPPH radical-scavenging activity at 0 days of storage, except for cooking loss. Overall, in breast meat of ducks, L* values at day 3 of storage and a* values at day 0 of storage were significantly influenced (p < 0.05) by treatments with different forms of HC and FRK. In conclusion, using either 1% HC and FRK pellets or pellets coated with HC and FRK at 1% resulted in a decrease in TBARS values and an increase in DPPH radical-scavenging activity during storage.(AU)


Subject(s)
Animals , Meat/analysis , Meat , Ducks/metabolism , Houttuynia , Infant Nutritional Physiological Phenomena
4.
Acta Sci. Anim. Sci. ; 37(3): 289-294, jul.-set. 2015. tab
Article in English | VETINDEX | ID: vti-684105

ABSTRACT

This study was a small pen trial in which we investigated comparative effects of dietary sea urchin shell powder and feed additives on meat quality and fatty acid profiles of broiler breast meat. A total of 108 male broilers were assigned to 3 groups (control, 1% sea urchin shell powder, and 1% feed additives) with 3 replicates of 12 chicks per pen in a completely randomized design for 28 days. The following parameters have been investigated: proximate composition (DM, CP, EE, and ash), physicochemical properties (pH, TBARS, cooking loss and DPPH radical scavenging), meat color and fatty acid profiles. No remarkable effects between treatment and storage day were observed for proximate composition, physicochemical properties, meat color and fatty acid profiles. In conclusion, diets with 1% sea urchin shell powder have the ability to increase DPPH radical scavenging and unsaturated fatty acid, indicating an opportunity for partial diet substitution in comparison with 1% feed additives.(AU)


Nesse ensaio investigaram-se os efeitos comparativos do pó da casca do ouriço-do-mar e suplementos alimentares sobre a qualidade de carne e o perfil de ácidos graxos de carne de peito de frangos de corte. Cento e oito frangos de corte machos foram distribuídos em 3 grupos (controle, 1% pó da casca do ouriço-do-mar, 1% aditivos alimentares), com 3 repetições, com 12 frangos por gaiola, num esquema aleatório, durante 28 dias. Foram investigados os seguintes parâmetros: composição aproximada (MS, PB, EE e cinzas), propriedades físico-químicas (pH, TBARS, perda no cozimento e o radical livre DPPH), cor da carne e ácidos graxos. Não foi observado nenhum efeito significativo entre o tratamento e o dia de armazenagem para a composição aproximada, propriedades físico-químicas, cor da carne e ácidos graxos. Os resultados mostram que rações com pó da casca do ouriço-do-mar são capazes de aumentar o radical livre DPPH e os ácidos graxos não saturados e revelam uma oportunidade para a substituição parcial da ração com 1% de aditivos alimentares.(AU)


Subject(s)
Animals , Dietary Supplements/adverse effects , Dietary Supplements/analysis , Animal Feed/analysis , Animal Feed , Poultry/anatomy & histology , Poultry/metabolism , Sea Urchins , Fatty Acids , Chemical Phenomena
5.
Acta sci., Anim. sci ; 37(3): 289-294, jul.-set. 2015. tab
Article in English | VETINDEX | ID: biblio-1459606

ABSTRACT

This study was a small pen trial in which we investigated comparative effects of dietary sea urchin shell powder and feed additives on meat quality and fatty acid profiles of broiler breast meat. A total of 108 male broilers were assigned to 3 groups (control, 1% sea urchin shell powder, and 1% feed additives) with 3 replicates of 12 chicks per pen in a completely randomized design for 28 days. The following parameters have been investigated: proximate composition (DM, CP, EE, and ash), physicochemical properties (pH, TBARS, cooking loss and DPPH radical scavenging), meat color and fatty acid profiles. No remarkable effects between treatment and storage day were observed for proximate composition, physicochemical properties, meat color and fatty acid profiles. In conclusion, diets with 1% sea urchin shell powder have the ability to increase DPPH radical scavenging and unsaturated fatty acid, indicating an opportunity for partial diet substitution in comparison with 1% feed additives.


Nesse ensaio investigaram-se os efeitos comparativos do pó da casca do ouriço-do-mar e suplementos alimentares sobre a qualidade de carne e o perfil de ácidos graxos de carne de peito de frangos de corte. Cento e oito frangos de corte machos foram distribuídos em 3 grupos (controle, 1% pó da casca do ouriço-do-mar, 1% aditivos alimentares), com 3 repetições, com 12 frangos por gaiola, num esquema aleatório, durante 28 dias. Foram investigados os seguintes parâmetros: composição aproximada (MS, PB, EE e cinzas), propriedades físico-químicas (pH, TBARS, perda no cozimento e o radical livre DPPH), cor da carne e ácidos graxos. Não foi observado nenhum efeito significativo entre o tratamento e o dia de armazenagem para a composição aproximada, propriedades físico-químicas, cor da carne e ácidos graxos. Os resultados mostram que rações com pó da casca do ouriço-do-mar são capazes de aumentar o radical livre DPPH e os ácidos graxos não saturados e revelam uma oportunidade para a substituição parcial da ração com 1% de aditivos alimentares.


Subject(s)
Animals , Poultry/anatomy & histology , Poultry/metabolism , Animal Feed , Animal Feed/analysis , Dietary Supplements/analysis , Dietary Supplements/adverse effects , Chemical Phenomena , Sea Urchins , Fatty Acids
SELECTION OF CITATIONS
SEARCH DETAIL