Methodological factors affecting gas and methane production during in vitro rumen fermentation evaluated by meta-analysis approach

Effects of some methodological factors on in vitro measures of gas production (GP, mL/g DM), CH4 production (mL/g DM) and proportion (% CH4 on total GP) were investigated by meta-analysis. These factors were considered: pressure in the GP equipment (0 = constant; 1 = increasing), incubation time (0 = 24; 1 = 65 48 h), time of rumen fluid collection (0 = before feeding; 1 = after feeding of donor animals), donor species of rumen fluid (0 = sheep; 1 = bovine), presence of N in the buffer solution (0 = presence; 1 = absence), and ratio between amount of buffered rumen fluid and feed sample (BRF/FS; 0 = 64 130 mL/g DM; 1 = 130\u2013140 mL/g DM; 2 = 65 140 mL/g DM). The NDF content of feed sample incubated (NDF) was considered as a continuous variable. From an initial database of 105 papers, 58 were discarded because one of the above-mentioned factors was not stated. After discarding 17 papers, the final dataset comprised 30 papers (339 observations). A preliminary mixed model analysis was carried out on experimental data considering the study as random factor. Variables adjusted for study effect were analyzed using a backward stepwise analysis including the above-mentioned variables. The analysis showed that the extension of incubation time and reduction of NDF increased GP and CH4 values. Values of GP and CH4 also increased when rumen fluid was collected after feeding compared to before feeding (+26.4 and +9.0 mL/g DM, for GP and CH4), from bovine compared to sheep (+32.8 and +5.2 mL/g DM, for GP and CH4), and when the buffer solution did not contain N (+24.7 and +6.7 mL/g DM for GP and CH4). The increase of BRF/FS ratio enhanced GP and CH4 production (+7.7 and +3.3 mL/g DM per each class of increase, respectively). In vitro techniques for measuring GP and CH4 production are mostly used as screening methods, thus a full standardization of such techniques is not feasible. However, a greater harmonization of analytical procedures (i.e., a reduction in the number of available protocols) would be useful to facilitate comparison between results of different experiments

Changes of particle size distribution and chemical composition of a hay-based ration offered once or twice daily to dairy cows

The objective of this experiment is to evaluate the changes of particle size distribution and chemical composition of the total mixed ration (TMR) based on hay as the main forage component ("dry" TMR) and distributed once (7.00 am) or twice (7.00 am and 1.00 pm) daily to 32 lactating cows. The trial was divided in two periods of 14 days each. Diet (DM=53.7%) was formulated in order to assure the nutritional requirements of cows producing 24 kg/d of milk (crude protein=14.4% DM; NDF=40.9% DM; milk FU=0.88/kg DM) and additional amounts of concentrates were distributed using automatic feeders. Four TMR samples were collected daily (7.00 am, 10.00 am, 1.00 pm, 4.00 pm) for six days during each experiment period for a total number of 48 feed samples. Each feed sample was subjected to the estimation of the particle size distribution using the separator of Pennsylvania State University composed of two sieves (diameters of 19 and 8 mm) and a collector on the bottom, and to the determination of the chemical composition. Changes of all three particle size fractions for TMRs were observed during the day with distributions of the TMR both once and twice daily. With the once daily distribution, the large particles fraction increased linearly (P<0.001) from 19.7 to 23.4, 32.2, and 35.1%, while the finest particle fraction decreased (from 60.1 to 58.3, 50.0, 47.8%). According to particle size changes, the chemical composition varied significantly at the different times of sampling when TMR was distributed once daily. Significant variations of DM were detected for TMR with a linear (P<0.001) increase (from 54.4 to 57.9, 60.7, 61.5%). Considering once TMR distribution, the values of NDF and starch showed an opposite trend with an increase of 6.5 and a decrease of 8.3 points from 7.00 am to 4.00 pm (i.e., 9 hrs after distribution). Correlations were estimated between chemical and physical characteristics of TMRs. NDF content was positively and significantly correlated to the fraction of particles retained by a 19 mm sieve (r=0.42; P<0.001) and negatively correlated with the smaller particles (r=-0.51; P<0.001). In conclusion, when the TMRs are prepared excluding corn/hay silages, twice daily distributions of diet can avoid the selection of large feed by the cows, thereby preserving both a uniform particle size distribution and a steady chemical composition of the diet during the day. However, the cost for the extra time needed for twice daily dis- tribution should be carefully considered

Interactions of the CCAAT-binding trimer NF-Y with nucleosomes

NF-Y is a sequence-specific evolutionary conserved activator binding to CCAAT boxes with high affinity and specificity. It is a trimer formed by NF-YA and two putative histone-like subunits, NF-YB and NF-YC, showing similarity to histones H2B and H2A, respectively. We investigated the relationships between NF-Y and chromatin using an Artemia franciscana chromatin assembly system with plasmids containing the Major HistoCompatibility complex class II Ea promoter. The NF-Y trimer, but not single subunits, protects the Y box in the presence of reconstituted chromatin, and it can bind the target sequence during and after assembly. Using reconstitution assays with purified chicken histones, we show that NF-Y associates with preformed nucleosomes. Translational analysis of various Ea fragments of identical length in which the CCAAT box is at different positions indicated that the lateral fragment was slightly more prone to NF-Y binding. In competition experiments, NF-Y is able to prevent formation of nucleosomes significantly. These data support the idea that NF-Y is a gene-specific activator with a built-in capacity to interface with chromatin structures

CAMOC – Um fórum interdisciplinar que se dedica aos museus de cidade e às cidades

CAMOC é um dos mais jovens comitês internacionais do ICOM – Conselho Internacional de Museus, organismo filiado à UNESCO, com sede em Paris, que mantém um Comitê Brasileiro com ampla atuação no país. É um fórum interdisciplinar para profissionais que trabalham ou se interessam por museus de cidade: planejadores urbanos, historiadores, antropólogos, economistas, arquitetos, geógrafos, museólogos, entre outros. Este comitê possibilita que os profissionais compartilhem conhecimento e experiência..

Museu da cidade de São Paulo: um novo olhar da sociomuseologia para uma megacidade

Orientação: Maria Cristina Oliveira BrunoEste estudo preocupa-se em discutir como a Sociomuseologia poderá se apropriar de um objeto de musealização mais amplo e abrangente, como o território de uma megacidade – no caso, São Paulo, Brasil. O Museu da Cidade de São Paulo, como objeto de estudo e de problematização museológica, busca explicitar uma metodologia interdisciplinar que enuncia a concepção de um novo modelo de museu de cidade, que tem como objeto de análise a grande metrópole, que se articula sobre as premissas de coleta contemporânea de acervo, empreendida por meio de métodos de mobilização social, em interlocução com as lógicas próprias do mundo globalizado, porém canonicamente erigida sobre os preceitos fundadores da Sociomuseologia. No cenário dos museus de território, este modelo busca fomentar um caminho novo e alternativo, que observa e interage em relação a uma realidade inerente à contemporaneidade, às megacidades, na medida em que busca problematizar e compreender as dinâmicas próprias da vida humana nestes imensos e complexos territórios. No século XXI, eleito como o ‘século das cidades’, abre-se, portanto, um novo campo teórico para a Museologia; como exercício fundador para este pretendido diálogo interdisciplinar, considera-se o museu como o palco natural e vocacional de vivência, representação e reflexão coletiva sobre a vida humana em sociedade, na era das macrocidades.The main concern of this study is to discuss how Sociomuseology can cope with a vast and encompassing object such as the territory of a megacity – specifically São Paulo, Brazil. The City Museum of São Paulo, as an object of study and museologic problematization, tries to present in a clear way an interdisciplinary methodology devoted to the conception of a new model of city museums, whose object of analysis is the great city, articulated upon the collection of contemporary items to be pursued by methods of social mobilization, interacting with the logic that characterizes a globalized world, but canonically based on the founding principles of Sociomuseology. Within the scenario of territory museums, this model tries to stimulate a new and alternative path that observes and interacts with the reality intrinsic to contemporary world, to megacities, as it tries to problematize and understand the dynamics connected to human life in those vast and complex territories. Therefore, along the twentieth century, elected as the "century of cities", a new theoretical field is opened to Museology; as a basic exercise for this intended interdisciplinary dialogue, the museum is considered to be the natural and vocational stage for experiencing, representing and collectively reflecting on human existence in society in the era of macrocities

The city museum of São Paulo: a new design for city museums in the era of the megacity

The City Museum of São Paulo as subject of study and museological challenge tries explicitly to present a multidisciplinary methodology - already tested in 2003 and 2004 - that enunciates the conception of a new model of city museum, whose objective is the analysis of the great metropolis São Paulo, articulated upon the collection of contemporary items to be pursued by methods of social mobilization, maintaining a dialogue with the proper logic of a globalised world, but canonically erected over the founding precepts of sociomuseology. Focusing on territory museums, that model tries to stimulate an alternative new path that observes and interacts with the reality that is inherent to contemporaneity, to Latin American megacities, as it endeavors to understand the dynamics, as well as the problems that characterise human life in those vast and complex territories.O Museu da Cidade de São Paulo, como objeto de estudo e de problematização museológica, busca explicitar uma metodologia interdisciplinar - já posta em teste em 2003 e 2004 - que enuncia a concepção de um novo modelo de museu de cidade, que tem como objeto de análise a grande metrópole São Paulo, que se articula sobre as premissas de coleta contemporânea de acervo, empreendida por meio de métodos de mobilização social, em interlocução com as lógicas próprias do mundo globalizado, porém canonicamente erigida sobre os preceitos fundadores da Sociomuseologia. Com foco no cenário dos museus de território, este modelo busca fomentar um caminho novo e alternativo, que observa e interage em relação a uma realidade inerente à contemporaneidade, às megacidades latino-americanas, na medida em que busca problematizar e compreender as dinâmicas próprias da vida humana nestes imensos e complexos territórios