239 research outputs found
Relative toxicity of gossypol enantiomers in laying and broiler breeder hens
Gossypol, a natural component of cottonseed
meal, exists in positive (+) or negative (−) enantiomeric
forms, and their levels and ratio could be altered
by developing new genetic strains of cotton. Two experiments
were conducted to determine the relative toxicity of
the individual gossypol enantiomers in laying and broiler
breeder hens. In the first experiment, 25 individually
caged Hy-Line W-36 forty-three-week-old laying hens
were fed a standard corn-soy diet supplemented with
either no gossypol or the individual enantiomers at 200
and 400 mg/kg of diet for 20 d (5 hens/treatment). In
the second experiment, 15 individually caged Cobb 500
fast-feathering 44-wk-old broiler breeder hens were fed
a standard corn-soy-wheat middlings diet supplemented
with either no gossypol or the individual enantiomers at
400 mg/kg of diet for 18 d (5 hens/treatment). In both
experiments, feed intake, egg production, and egg weight
were determined daily. All eggs were individually
opened and scored for yolk discoloration. At the end of
both experiments, several organ and tissue samples were
collected for gossypol analyses. In both experiments, the
addition of (+)-gossypol to the diet reduced egg production.
Only laying and broiler breeder hens fed (+)-gossypol
produced eggs with severe yolk discoloration (score
≥ 4). Total feed intake was lower (P < 0.05) in laying hens
fed the 400 mg/kg level of (+)-gossypol compared with
laying hens fed the other dietary treatments. In contrast,
broiler breeder hens consumed less of the diet supplemented
with (−)-gossypol. In both experiments, tissue
accumulation of (+)-gossypol was higher than (−)-gossypol,
with the exception of bile and excreta. The results
suggest that in hens the ingestion of (+)-gossypol has a
greater effect on egg yolk discoloration than the consumption
of (−)-gossypol
Relative toxicity of gossypol enantiomers in broilers
Use of cottonseed meal in poultry diets has
been avoided in large part because of fear of gossypol
toxicity. Gossypol exists naturally as a mixture of 2 enantiomers
that exhibit different biological activities. Two experiments
were conducted to determine the relative toxicity
of gossypol enantiomers on broilers. In the first experiment,
3-d-old broilers were fed a standard diet containing
0, 100, 200, 300, or 400 mg of gossypol from gossypol
acetic acid per kilogram of diet from 3 to 42 d of age.
This form of gossypol contains both enantiomers in an
equimolar ratio. Each dietary treatment consisted of 6
replicate pens of 4 birds. In the second experiment, 3-dold
broilers were divided into 15 pens of 4 birds each
and fed a standard diet supplemented with either no
gossypol or one of the gossypol enantiomers at 200 or
400 mg/kg of diet from 3 to 21 d of age. In both experiments,
feed intake and BW gain were measured. In addi-
(Key words: cottonseed meal, gossypol, gossypol enantiomer, broiler)
2005 Poultry Science 84:1376–1382
INTRODUCTION
Cottonseed meal (CSM) could be an attractive alternative
protein source for poultry diets, but concern over
the presence of the potentially toxic agent, gossypol, has
limited its use. Gossypol [1,1′,6,6′,7,7′-hexahydroxy-5,5′-
diisopropyl-3, 3′-dimethyl-(2, 2′- binaphthalene)-8, 8′-dicarboxaldehyde]
is a polyphenolic compound located in
pigment glands that are distributed throughout the cotton
plant. Gossypol is composed of 2 naphthalene rings with
restricted rotation around the bond connecting the rings.
As a result of this restricted rotation, gossypol occurs
naturally as a mixture of 2 enantiomers [(+)- and (−)-
2005 Poultry Science Association, Inc.
Received for publication February 7, 2005.
Accepted for publication May 5, 2005.
1This research was supported in part by grant 2631RE683-118 from
the Georgia Cotton Commission, Perry, GA.
2Mention of trade names or commercial products in this article is
solely for the purpose of providing specific information and does not
imply recommendation or endorsement by the US Department of Agriculture.
3To whom correspondence should be addressed: [email protected].
1376
tion, several organ and tissue samples were collected at
21 d (experiments 1 and 2) and 42 d (experiment 1) of
age and analyzed for gossypol. In experiment 1, feed
consumption and BW gain were reduced (P < 0.05) at 21
and 42 d for the birds fed the highest level of gossypol.
The concentration of gossypol in the heart, kidney, and
plasma were equivalent at 21 and 42 d of age. In experiment
2, total feed consumption was reduced only in birds
consuming (−)-gossypol, but BW gains were lower for
birds fed either enantiomer. However, (−)-gossypol was
more detrimental to growth than (+)-gossypol. The liver
had the highest tissue concentration of both enantiomers,
and accumulation of (+)-gossypol was higher than (−)-
gossypol in all tissues examined. No racemization of the
enantiomers was apparent in the tissues analyzed. Our
results indicated that both gossypol enantiomers were
toxic to broilers but that (−)-gossypol was more harmful
to efficient broiler production than (+)-gossypol
ProNodal acts via FGFR3 to govern duration of Shh expression in the prechordal mesoderm
The secreted glycoprotein sonic hedgehog (Shh) is expressed in the prechordal mesoderm, where it plays a crucial role in induction and patterning of the ventral forebrain. Currently little is known about how Shh is regulated in prechordal tissue. Here we show that in the embryonic chick, Shh is expressed transiently in prechordal mesoderm, and is governed by unprocessed Nodal. Exposure of prechordal mesoderm microcultures to Nodal-conditioned medium, the Nodal inhibitor CerS, or to an ALK4/5/7 inhibitor reveals that Nodal is required to maintain both Shh and Gsc expression, but whereas Gsc is largely maintained through canonical signalling, Nodal signals through a non-canonical route to maintain Shh. Further, Shh expression can be maintained by a recombinant Nodal cleavage mutant, proNodal, but not by purified mature Nodal. A number of lines of evidence suggest that proNodal acts via FGFR3. ProNodal and FGFR3 co-immunoprecipitate and proNodal increases FGFR3 tyrosine phosphorylation. In microcultures, soluble FGFR3 abolishes Shh without affecting Gsc expression. Further, prechordal mesoderm cells in which Fgfr3 expression is reduced by Fgfr3 siRNA fail to bind to proNodal. Finally, targeted electroporation of Fgfr3 siRNA to prechordal mesoderm in vivo results in premature Shh downregulation without affecting Gsc. We report an inverse correlation between proNodal-FGFR3 signalling and pSmad1/5/8, and show that proNodal-FGFR3 signalling antagonises BMP-mediated pSmad1/5/8 signalling, which is poised to downregulate Shh. Our studies suggest that proNodal/FGFR3 signalling governs Shh duration by repressing canonical BMP signalling, and that local BMPs rapidly silence Shh once endogenous Nodal-FGFR3 signalling is downregulated
Emotional valence and arousal affect reading in an interactive way: neuroimaging evidence for an approach-withdrawal framework
A growing body of literature shows that the emotional content of verbal material affects reading, wherein emotional words are given processing priority compared to neutral words. Human emotions can be conceptualised within a two-dimensional model comprised of emotional valence and arousal (intensity). These variables are at least in part distinct, but recent studies report interactive effects during implicit emotion processing and relate these to stimulus-evoked approach-withdrawal tendencies. The aim of the present study was to explore how valence and arousal interact at the neural level, during implicit emotion word processing. The emotional attributes of written word stimuli were orthogonally manipulated based on behavioural ratings from a corpus of emotion words. Stimuli were presented during an fMRI experiment while 16 participants performed a lexical decision task, which did not require explicit evaluation of a word's emotional content. Results showed greater neural activation within right insular cortex in response to stimuli evoking conflicting approach-withdrawal tendencies (i.e., positive high-arousal and negative low-arousal words) compared to stimuli evoking congruent approach vs. withdrawal tendencies (i.e., positive low-arousal and negative high-arousal words). Further, a significant cluster of activation in the left extra-striate cortex was found in response to emotional than neutral words, suggesting enhanced perceptual processing of emotionally salient stimuli. These findings support an interactive two-dimensional approach to the study of emotion word recognition and suggest that the integration of valence and arousal dimensions recruits a brain region associated with interoception, emotional awareness and sympathetic functions
Near infrared reflectance spectroscopy for the determination of free gossypol in cottonseed meal
Gossypol is a toxic polyphenolic compound produced by the pigment glands of the cotton
plant. The free gossypol content of cottonseed meal (CSM) is commonly determined by the
American Oil Chemists’ Society (AOCS) wet chemistry method. The AOCS method, however,
laboratory-intensive, time-consuming, and therefore, not practical for quick field analyses.
To determine if the free gossypol content of CSM could be predicted by near infrared reflectance
spectroscopy (NIRS), CSM samples were collected from all over the world. All CSM samples
were ground and a portion of each analyzed for free gossypol by the AOCS procedure (reference
data) and by NIRS (reflectance data). Both reflectance and reference data were combined in
calibration. The coefficient of determination (r2) and standard error of prediction (SEP) were
used to assess the calibration accuracy. The r2 was 0.728, and the SEP was 0.034 for the
initial calibration that included samples from all over the world. However, the r2 and SEP
improved to 0.921 and 0.014, respectively, if the calibration was made using CSM samples
only from the United States. These results indicate that a general prediction equation can be
developed to predict the free gossypol content of CSM by NIRS. From a practical standpoint,
NIRS technology provides a method for quickly assessing whether a particular batch of CSM
has a free gossypol content low enough to be suitable for use in poultry diets.This research was supported in part by grant 05-635GA from the Georgian Cotton Commission, Perry, G
Upgraded photon calorimeter with integrating readout for Hall A Compton Polarimeter at Jefferson Lab
The photon arm of the Compton polarimeter in Hall A of Jefferson Lab has been
upgraded to allow for electron beam polarization measurements with better than
1% accuracy. The data acquisition system (DAQ) now includes an integrating
mode, which eliminates several systematic uncertainties inherent in the
original counting-DAQ setup. The photon calorimeter has been replaced with a
Ce-doped GSO crystal, which has a bright output and fast response, and works
well for measurements using the new integrating method at electron beam
energies from 1 to 6 GeV.Comment: 16 pages, 15 figure
First measurement of direct photoproduction on the proton
We report on the results of the first measurement of exclusive
meson photoproduction on protons for GeV and GeV. Data were collected with the CLAS detector at the Thomas
Jefferson National Accelerator Facility. The resonance was detected via its
decay in the channel by performing a partial wave analysis of the
reaction . Clear evidence of the meson
was found in the interference between and waves at GeV. The -wave differential cross section integrated in the mass range of
the was found to be a factor of 50 smaller than the cross section
for the meson. This is the first time the meson has been
measured in a photoproduction experiment
Human Embryonic Stem Cell Technology: Large Scale Cell Amplification and Differentiation
Embryonic stem cells (ESC) hold the promise of overcoming many diseases as potential sources of, for example, dopaminergic neural cells for Parkinson’s Disease to pancreatic islets to relieve diabetic patients of their daily insulin injections. While an embryo has the innate capacity to develop fully functional differentiated tissues; biologists are finding that it is much more complex to derive singular, pure populations of primary cells from the highly versatile ESC from this embryonic parent. Thus, a substantial investment in developing the technologies to expand and differentiate these cells is required in the next decade to move this promise into reality. In this review we document the current standard assays for characterising human ESC (hESC), the status of ‘defined’ feeder-free culture conditions for undifferentiated hESC growth, examine the quality controls that will be required to be established for monitoring their growth, review current methods for expansion and differentiation, and speculate on the possible routes of scaling up the differentiation of hESC to therapeutic quantities
Sociocultural considerations in aging men's health: implications and recommendations for the clinician
http://dx.doi.org/10.1016/j.jomh.2009.07.00
Desenvolvimento de um roteiro conceitual para a gestão da biodiversidade e dos serviços ecossistêmicos no Caribe mexicano
Coral reefs and mangroves support rich biodiversity and provide ecosystem services that range from food, recreational benefits and coastal protection services, among others. They are one of the most threatened ecosystems by urbanization processes. In this context, we developed a conceptual framework for the management of biodiversity and ecosystem services for these coastal environments. We based our workflow on two sections: “Information base” and “Governance” and use the Puerto Morelos Coastal region as a case study for coastal protection. Puerto Morelos is between two of the most touristic destinations of Mexico (Playa del Carmen and Cancun) that has experienced an increase of population in the past four decades resulting in an intensification of multiple threats to its ecosystems. We characterized the two ecosystems with a “Management Units” strategy. An expert-based ecosystem services matrix was also described in order to connect mangroves and coral reef ecosystems with the multiple beneficiaries. Then an ecosystem model (conceptual model and Global Biodiversity model) was developed. The conceptual model was useful in understanding the interplay processes between systems regarding the ecosystem service of “Coastal Protection”. The Global Biodiversity model evidenced the human-induced shifts in the biodiversity for mangrove and coral reefs ecosystems. Also, a projection for 2035 of “best” and “worst” scenarios was applied using GLOBIO3. A DPSIR conceptual framework was used to analyze environmental problems regarding ecosystem services maintenance. Finally, we evaluated a set of policies associated with these ecosystems that favor coastal protection integrity. This framework facilitates the identification of the most relevant processes and controls about the provision of coastal protection service. It can also be useful to better target management actions and as a tool to identify future management needs to tackle the challenges preventing more effective conservation of coastal environments.Recifes de coral e manguezais possuem rica biodiversidade e fornecem serviços ecossistêmicos, tais como, alimento, recreação, proteção costeira, entre outros. Esses ecossistemas encontram-se entre os mais ameaçados pelos processos de urbanização. Nesse contexto, desenvolvemos um roteiro conceitual para a gestão da biodiversidade e dos serviços ecossistêmicos desses ambientes costeiros. Organizamos nossa sequência de passos de trabalho em duas seções: “Base de informações” e “Governança” e usamos a região costeira da cidade de Puerto Morelos (México) como um estudo de caso para analisar o serviço de proteção de costa. Puerto Morelos encontra-se entre dois dos destinos mais turísticos do México (Playa del Carmen e Cancún), e portanto sua população vem aumentando nas últimas quatro décadas, resultando na intensificação de múltiplas ameaças para os ecossistemas. Primeiramente, caracterizamos os dois ecossistemas identificando-os como “Unidades de Gestão”, detalhando seus principais componentes e processos. Através de uma “Matriz de serviços ecossistêmicos”, construída com base na opinião de especialistas, foram sistematizados os principais serviços ecossistêmicos prestados pelos manguezais e recifes de corais aos múltiplos beneficiários. Em seguida, foi desenvolvida uma modelagem do sistema (e ecossistemas) através de sua representação na forma de um modelo conceitual e um modelo numérico de Biodiversidade Global. O modelo conceitual facilitou a compreensão dos processos de interação entre sistemas em relação ao serviço “Proteção Costeira”. O modelo numérico evidenciou as mudanças induzidas pelo homem na biodiversidade dos ecossistemas de manguezal e recifes de coral. Além disso, uma projeção dos cenários “melhor” e “pior” foi desenvolvida para 2035 usando GLOBIO3. A Estrutura conceitual DPSIR foi aplicada para analisar problemas ambientais relacionados à manutenção dos serviços ecossistêmicos. Finalmente, avaliamos um conjunto de políticas públicas associadas a esses ecossistemas e que favorecem a integridade da proteção costeira. Portanto, o roteiro facilitou a identificação dos principais processos e controles para a provisão de um serviço ecossistêmico. Além disso, pode ser útil para direcionar melhor as ações de gerenciamento, bem como, uma ferramenta para identificar necessidades futuras de planejamento e gestão para enfrentar desafios que permitam uma conservação mais eficaz dos ambientes costeiros.Fil: Sánchez Quinto, Andrés. Universidad Nacional Autónoma de México; MéxicoFil: Costa, Julliet Correa da. Universidade Federal de Santa Catarina; BrasilFil: Zamboni, Nadia Selene. Universidade Federal do Rio Grande do Norte; BrasilFil: Sanches, Fábio H. C.. Universidade Federal de Sao Paulo; BrasilFil: Principe, Silas C.. Universidade de Sao Paulo; BrasilFil: Viotto, Evangelina del Valle. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Casagranda, Maria Elvira. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Lima, Francisco A. da Veiga. Universidade Federal de Santa Catarina; BrasilFil: Possamai, Bianca. Universidade Federal Do Rio Grande.; BrasilFil: Faroni Perez, Larisse. Universidade Federal de Juiz de Fora; Brasi
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