305 research outputs found
Absoaption and availability of phosphorus for pigs based on dilution of radiophosphorus (32P)
O fósforo tem função metabólica extremamente importante para o crescimento animal. É um dos minerais mais caros na formulação de rações, necessitando, desta forma, que a sua suplementação seja exata, para diminuir os custos. Este experimento visou mensurar a disponibilidade do P de uma dieta basal de milho e soja, com e sem suplementação de P inorgânico. Foram utilizados 16 suínos machos castrados, divididos em dois tratamentos. A técnica usada foi a diluição de isótopos; o P usado foi o fosfato de sódio (Na2H 32PO4). Os tratamentos, com e sem suplementação de P, apresentaram, respectivamente, os seguintes valores: absorção verdadeira, 2,50 e 1,90; disponibilidade verdadeira, 45,86 e 48,22%;ganho médio diário, 0,513 e 0,450 kg; consumo diário de alimento, 1,110 e 1,135 kg; e consumo diário do P, 3,44 e 3,97 g. A disponibilidade do P obtida para o fosfato bicálcico foi de 101,93% e a retenção de P absorvido foi de 96,28% e 96,79% para os respectivos tratamentos. Conclui-se que o P está sendo subestimado em sua taxa de absorção para dietas de milho e soja, e que a disponibilidade do P no fosfato bicálcico foi alta.The phosphorus metabolic function is extremely important for the animal's growth. The participation of P in the cost of rations is very high and this is one of the reasons to determine the exact amount needed in the rations to decrease the cost of formulation. This experiment was carried out aiming to measure the availability of P in a corn and soybean meal basal diet with and without supplementation o inorganic P. The technique used was the dilution of isotopes, and the P used was the sodium phosphate (Na2H 32PO4). The treatments with and without supplementary P presented respectively the following values: true absorption, 2.50 and 1.90 g; true availability, 45.86 and 48.22%; average daily gain, 0.513 and 0.450 kg; daily feed intake, 1.110 and 1.135 kg; and daily P consumption, 5.44 and 3.97 g. The P availability obtained for the bicalcium phosphate was 101.93% and the retention of the absorbed P was of 96.28% and 96.79% for the same treatments respectively. It was concluded that the P has been underestimated lo the formulation of diets based on com soybean meal, and the availability of P in the bicalcium phosphate was high
Co‐infection by classic MYXV and ha‐MYXV in Iberian hare (Lepus granatensis) and European wild rabbit (Oryctolagus cuniculus algirus)
Research Areas: Infectious Diseases ; Veterinary SciencesMyxomatosis is an emergent disease in the Iberian hare (Lepus granatensis). In this species, the disease is caused by a natural recombinant virus (ha-myxoma virus [MYXV]) identified for the first time in 2018 and has since been responsible for a large number of outbreaks in Spain and Portugal. The ha-MYXV, which harbours a 2.8 Kb insert-disrupting gene M009L, can also infect and cause disease in wild and domestic rabbits, despite being less frequently identified in rabbits. During the laboratory investigations of wild leporids found dead in Portugal carried out within the scope of a Nacional Surveillance Plan (Dispatch 4757/17, MAFDR), co-infection events by classic (MYXV) and naturally recombinant (ha-MYXV) strains were detected in both one Iberian hare and one European wild rabbit (Oryctolagus cuniculus algirus). These two cases were initially detected by a multiplex qPCR detection of MYXV and ha-MYXV and subsequently confirmed by conventional PCR and sequencing of the M009L gene, which contains an ha-MYXV-specific insertion. To our knowledge, this is the first documented report of co-infection by classic MYXV and ha-MYXV strains either in Iberian hare or in European wild rabbit. It is also the first report of infection of an Iberian hare by a classic MYXV strain. These findings highlight the continuous evolution of the MYXV and the frequent host range changes that justify the nonstop monitoring of the sanitary condition of wild Leporidae populations in the Iberian Peninsula.info:eu-repo/semantics/acceptedVersio
A quadruplex qPCR for detection and differentiation of classic and natural recombinant Myxoma Virus Strains of leporids
Research Areas: Biochemistry & Molecular Biology ; ChemistryA natural recombinant myxoma virus (referred to as ha-MYXV or MYXV-Tol08/18) emerged in the Iberian hare (Lepus granatensis) and the European rabbit (Oryctolagus cuniculus) in late 2018 and mid-2020, respectively. This new virus is genetically distinct from classic myxoma virus (MYXV) strains that caused myxomatosis in rabbits until then, by acquiring an additional 2.8 Kbp insert within the m009L gene that disrupted it into ORFs m009L-a and m009L-b. To distinguish ha-MYXV from classic MYXV strains, we developed a robust qPCR multiplex technique that combines the amplification of the m000.5L/R duplicated gene, conserved in all myxoma virus strains including ha-MYXV, with the amplification of two other genes targeted by the real-time PCR systems designed during this study, specific either for classic MYXV or ha-MYXV strains. The first system targets the boundaries between ORFs m009L-a and m009L-b, only contiguous in classic strains, while the second amplifies a fragment within gene m060L, only present in recombinant MYXV strains. All amplification reactions were validated and normalized by a fourth PCR system directed to a housekeeping gene (18S rRNA) conserved in eukaryotic organisms, including hares and rabbits. The multiplex PCR (mPCR) technique described here was optimized for Taqman® and Evagreen® systems allowing the detection of as few as nine copies of viral DNA in the sample with an efficiency > 93%. This real-time multiplex is the first fast method available for the differential diagnosis between classic and recombinant MYXV strains, also allowing the detection of co-infections. The system proves to be an essential and effective tool for monitoring the geographical spread of ha-MYXV in the hare and wild rabbit populations, supporting the management of both species in the field.info:eu-repo/semantics/publishedVersio
Predicting spectral features in galaxy spectra from broad-band photometry
We explore the prospects of predicting emission line features present in
galaxy spectra given broad-band photometry alone. There is a general consent
that colours, and spectral features, most notably the 4000 A break, can predict
many properties of galaxies, including star formation rates and hence they
could infer some of the line properties. We argue that these techniques have
great prospects in helping us understand line emission in extragalactic objects
and might speed up future galaxy redshift surveys if they are to target
emission line objects only. We use two independent methods, Artifical Neural
Neworks (based on the ANNz code) and Locally Weighted Regression (LWR), to
retrieve correlations present in the colour N-dimensional space and to predict
the equivalent widths present in the corresponding spectra. We also investigate
how well it is possible to separate galaxies with and without lines from broad
band photometry only. We find, unsurprisingly, that recombination lines can be
well predicted by galaxy colours. However, among collisional lines some can and
some cannot be predicted well from galaxy colours alone, without any further
redshift information. We also use our techniques to estimate how much
information contained in spectral diagnostic diagrams can be recovered from
broad-band photometry alone. We find that it is possible to classify AGN and
star formation objects relatively well using colours only. We suggest that this
technique could be used to considerably improve redshift surveys such as the
upcoming FMOS survey and the planned WFMOS survey.Comment: 10 pages 7 figures summitted to MNRA
Tipos de comedouros para suínos e efeito da forma física de rações sobre suas perdas
This experiment was carried out with the objective of comparing EMBRAPA’s prototype feeders (C1) and conventional feeders (C2), as well as two physical forms of rations, pelleted (R1) and meal (R2). The experimental design was the entirely randomized, with factorial structure 2 x 2 and with the experimental unit represented by the ration losses/pen/day. The utilized animals weighted 77.48 ± 0.48 kg, and the pens were of entirely stripped floor. An interaction statistically significant (P<0.01) was found among feeders and rations. Between C1 and C2 , R2 showed significantly (P<0.01) higher ration losses than R1 although proportionaly smaller for C2. The percentual loss of rations was 1.37 ± 0.58 and 0.99 ±0.22 for feeders C1 and C2, respectively.Este experimento foi conduzido durante o mês de outubro de 1982, tendo como objetivo a comparação de comedouros tipo EMBRAPA (C1) e convencional (C2), bem como a comparação de duas formas físicas de ração, peletizada (R1) e farelada (R2). O delineamento experimental foi o inteiramente casualizado, com estrutura fatorial 2 x 2. A unidade experimental foi representada pela perda de ração na baia, durante o dia. Os animais utilizados pesavam, em média, 77,48 ± 0,48 kg no início do experimento, e foram mantidos em baias de piso totalmente ripado. Foi constatada interação estatisticamente significativa (P<0,01) entre tipos de comedouros e forma física de ração. Dentro de C1 e C2, a R2 apresentou perda de ração significativamente maior (P<0,01) do que R1, embora, proporcionalmente menor em C2. A perda percentual de ração foi de 1,37 ±0,58 e 0,99% ± 0,22, para os comedouros C1 e C2, respectivamente
Interaction of the quantized electromagnetic field with atoms in the presence of dispersing and absorbing dielectric bodies
A general theory of the interaction of the quantized electromagnetic field
with atoms in the presence of dispersing and absorbing dielectric bodies of
given Kramers--Kronig consistent permittivities is developed. It is based on a
source-quantity representation of the electromagnetic field, in which the
electromagnetic-field operators are expressed in terms of a continuous set of
fundamental bosonic fields via the Green tensor of the classical problem.
Introducing scalar and vector potentials, the formalism is extended in order to
include in the theory the interaction of the quantized electromagnetic field
with additional atoms. Both the minimal-coupling scheme and the
multipolar-coupling scheme are considered. The theory replaces the standard
concept of mode decomposition which fails for complex permittivities. It
enables us to treat the effects of dispersion and absorption in a consistent
way and to give a unified approach to the atom-field interaction, without any
restriction to a particular interaction regime in a particular frequency range.
All relevant information about the dielectric bodies such as form and intrinsic
dispersion and absorption is contained in the Green tensor. The application of
the theory to the spontaneous decay of an excited atom in the presence of
dispersing and absorbing bodies is addressed.Comment: Paper presented at the International Conference on Quantum Optics and
VIII Seminar on Quantum Optics, Raubichi, Belarus, May 28-31, 2000, 14 pages,
LaTeX2e, no figure
Spillover events of rabbit haemorrhagic disease virus 2 (recombinant GI.4P-GI.2) from Lagomorpha to Eurasian badger
Áreas de pesquisa: Infectious Diseases ; Veterinary SciencesRabbit haemorrhagic disease (RHD) is a major threat to domestic and wild
European rabbits. Presently, in Europe, the disease is caused mainly by Rabbit
haemorrhagic disease virus 2 (RHDV2/b or Lagovirus europaeus GI.2), the origin
of which is still unclear, as no RHDV2 reservoir hosts were identified. After the
RHDV2 emergence in 2010, viral RNA was detected in a few rodent species.
Furthermore, RHDV2 was found to cause disease in some hare species resembling
the disease in rabbits, evidencing the ability of the virus to cross the species barrier. In this study, through molecular, histopathologic, antigenic and morphological
evidences, we demonstrate the presence and replication of RHDV2 in Eurasian
badgers (Meles meles) found dead in the district of Santarém, Portugal, between
March 2017 and January 2020. In these animals, we further classify the RHDV2
as a Lagovirus europaeus recombinant GI.4P-GI.2. Our results indicate that Meles
meles is susceptible to RHDV2, developing systemic infection, and excreting the
virus in the faeces. Given the high viral loads seen in several organs and matrices,
we believe that transmission to the wild rabbit is likely. Furthermore, transmission
electron microscopy data show the presence of calicivirus compatible virions in
the nucleus of hepatocytes, which constitutes a paradigm shift for caliciviruses’
replication cycleinfo:eu-repo/semantics/publishedVersio
Galaxy clusters identified from the SDSS DR6 and their properties
Clusters of galaxies in most previous catalogs have redshifts z<0.3. Using
the photometric redshifts of galaxies from the Sloan Digital Sky Survey Data
Release 6 (SDSS DR6), we identify 39,668 clusters in the redshift range 0.05< z
<0.6 with more than eight luminous (M_r<-21) member galaxies. Cluster redshifts
are estimated accurately with an uncertainty less than 0.022. The contamination
rate of member galaxies is found to be roughly 20%, and the completeness of
member galaxy detection reaches to ~90%. Monte Carlo simulations show that the
cluster detection rate is more than 90% for massive (M_{200}>2\times10^{14}
M_{\odot}) clusters of z<0.42. The false detection rate is ~5%. We obtain the
richness, the summed luminosity, and the gross galaxy number within the
determined radius for identified clusters. They are tightly related to the
X-ray luminosity and temperature of clusters. Cluster mass is related to the
richness and summed luminosity with M_{200}\propto R^{1.90\pm0.04} and
M_{200}\propto L_r^{1.64\pm0.03}, respectively. In addition, 685 new candidates
of X-ray clusters are found by cross-identification of our clusters with the
source list of the ROSAT X-ray survey.Comment: 18 pages, 27 figures, 2 tables. Further modefication on Table 1 and
Table 2 after formal publication on ApJS. No changes on conclusions except
for the number of clusters we found. The updated tables are available at
"http://159.226.88.6/zmtt/wzl/CV_wen.htm
Antioxidant pathways are up-regulated during biological nitrogen fixation to prevent ROS-induced nitrogenase inhibition in Gluconacetobacter diazotrophicus
Gluconacetobacter diazotrophicus, an endophyte isolated from sugarcane, is a strict aerobe that fixates N2. This process is catalyzed by nitrogenase and requires copious amounts of ATP. Nitrogenase activity is extremely sensitive to inhibition by oxygen and reactive oxygen species (ROS). However, the elevated oxidative metabolic rates required to sustain biological nitrogen fixation (BNF) may favor an increased production of ROS. Here, we explored this paradox and observed that ROS levels are, in fact, decreased in nitrogen-fixing cells due to the up-regulation of transcript levels of six ROS-detoxifying genes. A cluster analyses based on common expression patterns revealed the existence of a stable cluster with 99.8% similarity made up of the genes encoding the α-subunit of nitrogenase Mo–Fe protein (nifD), superoxide dismutase (sodA) and catalase type E (katE). Finally, nitrogenase activity was inhibited in a dose-dependent manner by paraquat, a redox cycler that increases cellular ROS levels. Our data revealed that ROS can strongly inhibit nitrogenase activity, and G. diazotrophicus alters its redox metabolism during BNF by increasing antioxidant transcript levels resulting in a lower ROS generation. We suggest that careful controlled ROS production during this critical phase is an adaptive mechanism to allow nitrogen fixation
- …