1,057 research outputs found
Salmonella serology - which samples should be used: comparison of meatjuice and serum samples of the same pigs
Contamination of pork with Salmonella typhimurium is a potential source for fatal food born Salmonella-infections in humans. Screening programs are used in a number of countries to categorize pig farms into 3-4 Salmonella-risk-categories. A similar program will soon be implemented by the German government as well
Recomendações para inoculação e peletizacao de sementes de leguminosas forrageiras tropicais.
Este trabalho teve por objetivo testar um produto adesivo de fácil obtenção e baixo preço, bem como verificar a adequação dos fosfatos de rocha regionais para formação de "pelets" e sua influência na sobrevivência do inoculante, aplicado a semente de diversas leguminosas forrageiras tropicais de interesse regional. Os resultados obtidos permitiram elaborar recomendações praticas (Tabela 2) que se encontram anexas.bitstream/item/138503/1/COT-17.pdfCNPG
Verhaltensbiologische und genetische Untersuchungen zu Paarungsbarrieren zwischen Populationen des Dreistachligen Stichlings (Gasterosteus aculeatus) in Schleswig-Holstein
Zwischen See- und Flusspopulationen von G. aculeatus in Schleswig-Holstein findet kein oder kaum Genfluss statt. Da prinzipielle geografische Barrieren fehlen, müssen ökologische oder ethologische Paarungsbarrieren vorhanden sein. Eine Möglichkeit wäre assortative Partnerwahl anhand olfaktorischer Signale durch die Weibchen. Weibliche Stichlinge wählen Paarungspartner u.a. anhand von Signalen über die Kombination der MHC Klasse IIB-Allele der potentiellen Partner. Da sich See- und Flusspopulationen am MHC Klasse IIB unterscheiden, ist es denkbar, dass die Weibchen anhand dieser Unterschiede assortativ paaren. In dieser Arbeit habe ich das Vorhandensein eines solchen Mechanismus in zwei Experimenten untersucht. In Versuchen zur MHC-abhängigen Partnerwahl zeigten die Weibchen allerdings keine Bevorzugung eines Männchens mit MHC-Genotyp aus dem Ursprungshabitat gegenüber einem Männchen mit MHC-Genotyp aus dem fremden Habitat. Entsprechend zeigten die Weibchen in Versuchen zur habitatabhängigen Partnerwahl keine Präferenz für ein Männchen aus dem Ursprungshabitat gegenüber einem fremden Männchen anhand allgemeiner olfaktorischer Signale. Meine Arbeit lässt daher vermuten, dass die Paarungsbarriere zwischen See- und Flusspopulationen von G. aculeatus nicht auf assortativer Partnerwahl der Weibchen aufgrund olfaktorischer Signale basiert. Allerdings kann ich eine olfaktorische Paarungsbarriere auch nicht sicher ausschließen. Die Habitate See und Fluss unterscheiden sich ökologisch in verschiedenen Punkten. Divergierende Selektion kann daher zu Unterschieden in vielen morphologischen oder ethologischen Merkmalen führen, auf denen die reproduktive Isolation zwischen See- und Flusspopulationen beruhen kann. Ein weiterer Schritt sollte demnach darin bestehen, andere mögliche Faktoren für das Vorhandensein der genetischen Divergenz zwischen See- und Flusspopulationen von G. aculeatus zu betrachten.1 Einleitung......................................................................................................... 5 1.1 Arten und ihre Entstehung ......................................................................... 5 1.2 Evolutionsbiologie des Dreistachligen Stichlings ...................................... 8 1.3 Paarungsverhalten des Dreistachligen Stichlings .................................... 10 1.4 Funktion und Struktur des MHC.............................................................. 11 1.5 Diversität des MHC und Partnerwahl ...................................................... 13 1.6 Zielsetzung dieser Arbeit........................................................................... 16 2 Material und Methoden ............................................................................ 21 2.1 Experiment 1: Versuche zur MHC-abhängigen Partnerwahl................. 21 2.1.1 Herkunft und Hälterung der Fische .................................................. 21 2.1.2 Versuche zur MHC-abhängigen Partnerwahl .................................. 24 2.1.3 Genotypisierung.................................................................................. 30 2.1.4 Statistische Analyse............................................................................. 32 2.2 Experiment 2: Versuche zur habitatabhängigen Partnerwahl................ 32 2.2.1 Herkunft und Hälterung der Fische .................................................. 32 2.2.2 Versuche zur habitatabhängigen Partnerwahl.................................. 33 2.2.3 Statistische Analyse............................................................................. 34 3 Ergebnisse ...................................................................................................... 35 3.1 Experiment 1: Versuche zur MHC-abhängigen Partnerwahl................. 35 3.1.1 Genetische Differenzierung und Diversität der MHC Klasse IIBGene der Versuchsfische ............................................................................. 35 3.1.2 Versuche zur MHC-abhängigen Partnerwahl .................................. 37 3.2 Experiment 2: Versuche zur habitatabhängigen Partnerwahl................ 39 4 Diskussion ...................................................................................................... 41 4.1 Experiment 1: Versuche zur MHC-abhängigen Partnerwahl................. 41 4.2 Experiment 2: Versuche zur habitatabhängigen Partnerwahl................ 45 4.3 Allgemeine Betrachtung............................................................................ 46 5 Zusammenfassung ....................................................................................... 51 6 Literatur.......................................................................................................... 53 7 Danksagung ................................................................................................... 65 8 Stellungnahme.............................................................................................. 6
Reciclagem de nitrogênio em pastagem consorciada de Calopogonium mucunoides com Brachiaria decumbens.
O trabalho estuda a reciclagem de nitrogênio (N) de Calopogonium mucunoides associado com Brachiaria decumbens, sob pastejo continuo, com lotação de 2,5 U.A/ha. As avaliações foram efetuadas através da medida de crescimento da matéria seca (MS) da gramÃnea e da leguminosa e da quantidade de N em Kg/ha, mobilizada pelo crescimento para a biomassa das plantas da pastagem. Efetuaram-se avaliações do N total e N assimilável (amônia + nitrato) no perfil do solo, a profundidade de 0 a 250 cm, bem como do desempenho do Rhizobium associado a leguminosa. Pode-se determinar que, a consorciação, o crescimento da gramÃnea, que mobilizou do solo para a vegetação 105,47 kg de N/ha, foi acrescido de mais 81,37 kg de N/ha por ano, mobilizado pelo crescimento da leguminosa.Na pastagem de gramÃnea pura, o N mobilizado do solo foi de 123,10 kg de N/ha. e uma diferença significativa (P<0,05) de 63,84 kg de N/ha por ano foi adicionada ao sistema da pastagem, sendo atribuÃda em sua maior parte a fixação simbiótica, realizada pelo Calopogonium mucunoides. O N reciclado resultou um aumento significativo (P<0,05) na oferta de N e proteÃna bruta na forragem disponÃvel do pasto consociado, ao longo do ano. A leguminosa foi responsável também por um aumento significativo (P<0,05) da percentagem de N total na camada superficial do solo e aumentou significativamente (P<0,05) o conteúdo de N assimilável no perfil. Os estudos realizados em casa de vegetação, com Rhizobium isolado de plantas da pastagem, indicaram que a estirpe associada...bitstream/item/104558/1/Reciclagem-de-nitrogenio-em-pastagem.pd
Consorciação de pastagem de Brachiaria decumbens Stapf v. Australiana, com leguminosas plantadas em faixas e sob condições de pastejo.
As pastagens de Brachiaria decumbens apos alguns anos de utilização podem apresentar um decréscimo na produção de matéria seca (MS) resultando em menor capacidade de suporte. Visando solucionar esse problema foi estabelecido um experimento com o objetivo de se manter ou elevar a produtividade de pastagens de B. decumbens pela introdução de leguminosas. As leguminosas foram estabelecidas em faixas onde estão sendo feitas avaliações de persistência das mesmas.bitstream/item/137377/1/PESQ-EM-ANDAMENTO-07.pd
Isolation and separation of inositol phosphates from hydrolysates of rat tissues
1. 1.An electrophoretic method for the rapid separation of the phosphate esters of inositol is presented.2. 2.It is used, together with ion-exchange chromatography, to establish the presence of inositol di- and triphosphates in hydrolysates of trichloroacetic acid residues of rat brain, liver, heart, kidney, and lung.3. 3.With the aid of a 32P marker, inositol di- and triphosphates were also found in hydrolysates of rat erythrocyte stroma.4. 4.Glycerol diphosphate was found in hydrolysates of rat liver.5. 5.Inositol tetraphosphate was not found in the hydrolysates of any of the tissues studied.6. 6.Residues remaining after extraction of rat brain by established lipid extraction procedures retained substantial amounts of bound inositol di- and triphosphates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32019/1/0000061.pd
Planck intermediate results. XVII. Emission of dust in the diffuse interstellar medium from the far-infrared to microwave frequencies
The dust-Hi correlation is used to characterize the emission properties of dust in the diffuse interstellar medium (ISM) from far infrared wavelengths to microwave frequencies. The field of this investigation encompasses the part of the southern sky best suited to study the cosmic infrared and microwave backgrounds. We cross-correlate sky maps from Planck, the Wilkinson Microwave Anisotropy Probe (WMAP), and the diffuse infrared background experiment (DIRBE), at 17 frequencies from 23 to 3000 GHz, with the Parkes survey of the 21 cm line emission of neutral atomic hydrogen, over a contiguous area of 7500 deg^2 centred on the southern Galactic pole. We present a general methodology to study the dust-Hi correlation over the sky, including simulations to quantify uncertainties. Our analysis yields four specific results. (1) We map the temperature, submillimetre emissivity, and opacity of the dust per H-atom. The dust temperature is observed to be anti-correlated with the dust emissivity and opacity. We interpret this result as evidence of dust evolution within the diffuse ISM. The mean dust opacity is measured to be (7.1 ± 0.6) × 10^(-27) cm^2 H^(-1) × (ν/ 353 GHz)^(1.53 ± 0.03) for 100 ≤ ν ≤ 353 GHz. This is a reference value to estimate hydrogen column densities from dust emission at submillimetre and millimetre wavelengths. (2) We map the spectral index βmm of dust emission at millimetre wavelengths (defined here as ν ≤ 353 GHz), and find it to be remarkably constant at β_(mm) = 1.51 ± 0.13. We compare it with the far infrared spectral index β_(FIR) derived from greybody fits at higher frequencies, and find a systematic difference, β_(mm) – β_(FIR) = − 0.15, which suggests that the dust spectral energy distribution (SED) flattens at ν ≤ 353 GHz. (3) We present spectral fits of the microwave emission correlated with Hi from 23 to 353 GHz, which separate dust and anomalous microwave emission (AME). We show that the flattening of the dust SED can be accounted for with an additional component with a blackbody spectrum. This additional component, which accounts for (26 ± 6)% of the dust emission at 100 GHz, could represent magnetic dipole emission. Alternatively, it could account for an increasing contribution of carbon dust, or a flattening of the emissivity of amorphous silicates, at millimetre wavelengths. These interpretations make different predictions for the dust polarization SED. (4) We analyse the residuals of the dust-Hi correlation. We identify a Galactic contribution to these residuals, which we model with variations of the dust emissivity on angular scales smaller than that of our correlation analysis. This model of the residuals is used to quantify uncertainties of the CIB power spectrum in a companion Planck paper
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