Consumo, produção, composição do leite e parâmetros ruminais de vacas Holândes x Zebu recebendo dietas baseadas em cana de açúcar ou silagem de milho, suplementadas com concentrados.

O experimento foi realizado na Embrapa Gado de Leite (Coronel Pacheco, MG) com o objetivo de avaliar o consumo, a produção e composição do leite, e os parâmetros ruminais de vacas Holandês x Zebu no terço médio da lactação (175±20 dias), produzindo de 7,4 a 9,0 kg/dia de leite, canuladas no rúmen, recebendo dietas baseadas na combinação de cana-de-açúcar picada (CP) ou silagem de milho (SM), na base de 85% da matéria seca (MS), com os concentrados fubá de milho (FM) ou farelo de trigo (FT) (15% da MS), em delineamento Quadrado Latino com arranjo fatorial 2 x 2 (volumosos x concentrados). As composições químicas das dietas CP+FM; CP+FT; SM+FM; e SM+FT foram, respectivamente, de 12,7; 12,5; 12,8 e 12,2% de proteína bruta; e de 49,0; 51,1; 49,9 e 56,7% de fibra em detergente neutro (FDN). Não houve efeito (P>0,05) do tipo de suplemento concentrado sobre os consumos de MS e de FDN nem sobre a produção e composição do leite. As dietas baseadas em silagem de milho apresentaram produção de leite 17% maior (P0,05) entre as dietas quanto ao pH e às concentrações ruminais de nitrogênio amoniacal, que variaram (P<0,0001) em função do tempo de amostragem, permanecendo em faixas favoráveis para o crescimento e desenvolvimento da microbiota fibrolítica ruminal

Cinética de trânsito das fases líquidas e sólida de dietas baseadas em cana-de-açúcar ou silagem de milho suplementadas com concentrados e fornecidas para vacas Holândes x Zebu em lactação.

O experimento foi realizado na Embrapa Gado de Leite (Coronel Pacheco, MG), com o objetivo de avaliar parâmetros da cinética de trânsito das fases sólida e líquida em vacas Holandês x Zebu no terço médio da lactação (175±20 dias), produzindo de 7,4 a 9,0 kg/dia de leite, canuladas no rúmen, recebendo dietas baseadas em combinações de dois alimentos volumosos (cana-de-açúcar picada ou silagem de milho) com dois suplementos concentrados (fubá de milho ou farelo de trigo), em delineamento em Quadrado Latino com arranjo fatorial 2 x 2 (tipo de volumoso x tipo de concentrado). Para estimativa dos parâmetros das cinéticas de trânsito das fases sólida e líquida, modelos não-lineares foram, respectivamente, ajustados aos dados de excreção fecal de Cromo e de concentrações de Cobalto no líquido ruminal. As composições químicas médias das dietas avaliadas (cana-de-açúcar + fubá de milho; cana-de-açúcar + farelo de trigo; silagem de milho + fubá de milho; e silagem de milho + farelo de trigo) foram, respectivamente, de 12,7; 12,5; 12,8 e 12,2% de proteína bruta; e de 49,0; 51,1; 49,9 e 56,7% de fibra em detergente neutro (FDN). Os respectivos consumos de matéria seca e de FDN (porcentagem do peso vivo, %PV) das quatro dietas foram de 2,02 e 0,98%PV; 2,23 e 1,13%PV; 2,57 e 1,28%PV e 2,22 e 1,25%PV, enquanto que as taxas de passagem ruminais estimadas para as fases sólida e líquida foram de 5,63 e 8,39%/h; 5,97 e 7,07%/h; 5,43 e 7,60%/h; e 5,74 e 7,33%/h

Activity Patterns during Food Provisioning Are Affected by Artificial Light in Free Living Great Tits (Parus major)

Artificial light may have severe ecological consequences but there is limited experimental work to assess these consequences. We carried out an experimental study on a wild population of great tits (Parus major) to assess the impact of light pollution on daily activity patterns during the chick provisioning period. Pairs that were provided with a small light outside their nest box did not alter the onset, cessation or duration of their working day. There was however a clear effect of artificial light on the feeding rate in the second half of the nestling period: when provided with artificial light females increased their feeding rate when the nestlings were between 9 and 16 days old. Artificial light is hypothesised to have affected the perceived photoperiod of either the parents or the offspring which in turn led to increased parental care. This may have negative fitness consequences for the parents, and light pollution may thus create an ecological trap for breeding birds

Neuroinflammation, Mast Cells, and Glia: Dangerous Liaisons

The perspective of neuroinflammation as an epiphenomenon following neuron damage is being replaced by the awareness of glia and their importance in neural functions and disorders. Systemic inflammation generates signals that communicate with the brain and leads to changes in metabolism and behavior, with microglia assuming a pro-inflammatory phenotype. Identification of potential peripheral-to-central cellular links is thus a critical step in designing effective therapeutics. Mast cells may fulfill such a role. These resident immune cells are found close to and within peripheral nerves and in brain parenchyma/meninges, where they exercise a key role in orchestrating the inflammatory process from initiation through chronic activation. Mast cells and glia engage in crosstalk that contributes to accelerate disease progression; such interactions become exaggerated with aging and increased cell sensitivity to stress. Emerging evidence for oligodendrocytes, independent of myelin and support of axonal integrity, points to their having strong immune functions, innate immune receptor expression, and production/response to chemokines and cytokines that modulate immune responses in the central nervous system while engaging in crosstalk with microglia and astrocytes. In this review, we summarize the findings related to our understanding of the biology and cellular signaling mechanisms of neuroinflammation, with emphasis on mast cell-glia interactions

Light pollution: The possible consequences of excessive illumination on retina

Light is the visible part of the electromagnetic radiation within a range of 380-780 nm; (400-700 on primates retina). In vertebrates, the retina is adapted to capturing light photons and transmitting this information to other structures in the central nervous system. In mammals, light acts directly on the retina to fulfill two important roles: (1) the visual function through rod and cone photoreceptor cells and (2) non-image forming tasks, such as the synchronization of circadian rhythms to a 24 h solar cycle, pineal melatonin suppression and pupil light reflexes. However, the excess of illumination may cause retinal degeneration or accelerate genetic retinal diseases. In the last century human society has increased its exposure to artificial illumination, producing changes in the Light/Dark cycle, as well as in light wavelengths and intensities. Although, the consequences of unnatural illumination or light pollution have been underestimated by modern society in its way of life, light pollution may have a strong impact on people's health. The effects of artificial light sources could have direct consequences on retinal health. Constant exposure to different wavelengths and intensities of light promoted by light pollution may produce retinal degeneration as a consequence of photoreceptor or retinal pigment epithelium cells death. In this review we summarize the different mechanisms of retinal damage related to the light exposure, which generates light pollution.Fil: Contin, Maria Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Benedetto, María Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Quinteros Quintana, María Luz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Guido, Mario Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentin

Effects of circadian disruption on physiology and pathology: from bench to clinic (and back)

Nested within the hypothalamus, the suprachiasmatic nuclei (SCN) represent a central biological clock that regulates daily and circadian (i.e., close to 24 h) rhythms in mammals. Besides the SCN, a number of peripheral oscillators throughout the body control local rhythms and are usually kept in pace by the central clock. In order to represent an adaptive value, circadian rhythms must be entrained by environmental signals or zeitgebers, the main one being the daily light?dark (LD) cycle. The SCN adopt a stable phase relationship with the LD cycle that, when challenged, results in abrupt or chronic changes in overt rhythms and, in turn, in physiological, behavioral, and metabolic variables. Changes in entrainment, both acute and chronic, may have severe consequences in human performance and pathological outcome. Indeed, animal models of desynchronization have become a useful tool to understand such changes and to evaluate potential treatments in human subjects. Here we review a number of alterations in circadian entrainment, including jet lag, social jet lag (i.e., desynchronization between body rhythms and normal time schedules), shift work, and exposure to nocturnal light, both in human subjects and in laboratory animals. Finally, we focus on the health consequences related to circadian/entrainment disorders and propose a number of approaches for the management of circadian desynchronization.Fil: Chiesa, Juan José. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Duhart, José Manuel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Casiraghi, Leandro Pablo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Paladino, Natalia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bussi, Ivana Leda. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Golombek, Diego Andrés. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin