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1.
Animal ; 18(4): 101120, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38520772

RESUMO

In stabled horses, several behaviours are considered to be important indicators of the state of welfare at the individual level: stereotypies, aggressive behaviours towards humans and the "withdrawn", alert, sternal, lateral and observation postures. Until now, these behaviours have been extensively studied in relation to different horse management practices. However, little is known about their changes or consistency over time. This study aimed to investigate differences in the expression of these behaviours assessed on 44 stabled horses during an initial 3-month period and then again on the same individuals 2 years later. Out of the six behaviours studied, two showed significant differences between the 2 years with medium effect sizes: the levels of aggressiveness towards humans increased (Wilcoxon signed-rank test: V = 65, P = 0.005) and those of recumbent rest during the day decreased (V = 416, P < 0.001) over time. The results also suggested limited evidence of major changes over time in the expression of stereotypies, the "withdrawn", alert and observation postures. However, the principal component analyses carried out on all the behaviours showed that alert and observation postures may slightly decrease over time for some individuals. Regarding stereotypies and the "withdrawn" posture, the results mainly suggested a change at the individual level in the expression of these behaviours over time. This study provided new insights into the dynamic nature of several behaviours when the horses' living conditions are not fundamentally altered and raised hypotheses about the state of welfare of stabled individuals over a 2-year period.


Assuntos
Agressão , Comportamento Animal , Humanos , Cavalos , Animais , Postura
2.
Nat Commun ; 13(1): 2012, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35440629

RESUMO

Transcriptionally active loci are particularly prone to breakage and mounting evidence suggests that DNA Double-Strand Breaks arising in active genes are handled by a dedicated repair pathway, Transcription-Coupled DSB Repair (TC-DSBR), that entails R-loop accumulation and dissolution. Here, we uncover a function for the Bloom RecQ DNA helicase (BLM) in TC-DSBR in human cells. BLM is recruited in a transcription dependent-manner at DSBs where it fosters resection, RAD51 binding and accurate Homologous Recombination repair. However, in an R-loop dissolution-deficient background, we find that BLM promotes cell death. We report that upon excessive RNA:DNA hybrid accumulation, DNA synthesis is enhanced at DSBs, in a manner that depends on BLM and POLD3. Altogether our work unveils a role for BLM at DSBs in active chromatin, and highlights the toxic potential of RNA:DNA hybrids that accumulate at transcription-associated DSBs.


Assuntos
Cromatina , Quebras de DNA de Cadeia Dupla , Cromatina/genética , DNA/genética , DNA/metabolismo , Reparo do DNA , Humanos , RNA/genética , RecQ Helicases/genética , RecQ Helicases/metabolismo , Reparo de DNA por Recombinação
3.
Animal ; 11(2): 335-344, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27476550

RESUMO

Responses to changes in dietary Lys and other essential amino acid (AA) concentrations were evaluated in 480 male and female broilers originating from two lines divergently selected for high (pHu+) or low (pHu-) ultimate pH (pHu) of breast muscle. The two genetic lines were fed with two grower isoenergetic diets differing in both true digestible Lys (control=10.2 g/kg and experimental=7.0 g/kg) and amounts of other essential AA calculated in relation to Lys, which were sufficient for the control diet or in excess for the experimental diet. There were six repetitions per treatment. Birds were weighed individually at days 0, 21, 28 and 43. Feed consumption was recorded per pen and feed conversion was calculated over the growing period. The physical activity and walking ability of broilers were recorded during the whole rearing period. Breast and leg yield, and abdominal fat percentage were measured at 43 days of age, as were pHu, color, drip and cooking loss, Warner-Bratzler shear force, and curing-cooking yield of the breast Pectoralis major and pHu of the thigh Sartorius muscle. Divergent selection greatly affected most breast meat quality traits without significantly changing growth rate or feed efficiency. When subjected to a variation in dietary intake of AA, birds from the two genotypes responded in a similar way in terms of animal's growth, feed efficiency, body composition and meat quality traits. Although line and diet did not affect physical or feeding activities of the broilers, a significant effect of line-by-diet interaction was observed on gait score. Contrary to the pHu- birds, the walking ability of pHu+ birds was impaired when fed the control diet that favored growth and breast muscle development and limited storage of carbohydrate in muscle.


Assuntos
Ração Animal/análise , Dieta/veterinária , Carne/análise , Músculos Peitorais/anatomia & histologia , Aminoácidos/metabolismo , Animais , Composição Corporal , Cruzamento , Galinhas/anatomia & histologia , Galinhas/genética , Feminino , Concentração de Íons de Hidrogênio , Masculino , Músculo Esquelético/metabolismo , Músculos Peitorais/fisiologia , Seleção Genética
4.
J Agric Food Chem ; 63(19): 4799-804, 2015 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-25905677

RESUMO

Chymosin is the major enzyme of natural rennet, traditionally used in cheese making for its high milk-clotting activity. For technical reasons, an accurate characterization of rennet should include its total clotting activity and also its enzymatic composition. Monoclonal antibodies specific to chymosin were obtained from mice immunized with purified bovine chymosin, and an inhibition enzyme-linked immunosorbent assay (ELISA) was developed for the quantification of chymosin in solution. No cross-reactivity was observed with other milk-clotting enzymes commonly used in cheese making. The limit of detection and limit of quantification were 125 and 400 ng/mL, respectively. The values of precision within and among runs were 7.23 and 7.39%, respectively, and satisfying recovery, from 92 to 119%, was found for spiked samples. The inhibition ELISA was successfully applied to commercial rennets, and the results were consistent with those obtained using the standard chromatographic method (IDF 110: A, 1987).


Assuntos
Queijo/análise , Quimosina/análise , Ensaio de Imunoadsorção Enzimática/métodos , Aditivos Alimentares/análise , Leite/química , Animais , Anticorpos Monoclonais/análise , Bovinos , Camundongos
5.
Animal ; 9(2): 331-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25354525

RESUMO

Animals perceiving repeated aversive events can become chronically stressed. Chronic activation of the hypothalamic-pituitary-adrenal (HPA) axis can have deleterious consequences on physiological parameters (e.g. BW, blood chemistry) and behaviour (e.g. emotional reactivity, stereotypies, cognition). Environmental enrichment (EE) can be a mean to reduce animal stress and to improve welfare. The aim of this study was first, to assess the effects of EE in battery cages on the behaviour of young Japanese quail and second, to evaluate the impact of EE on quail exposed to chronic stress. The experiment involved quail housed in EE cages and submitted or not to a chronic stress procedure (CSP) (EE cages, control quail: n=16, CSP quail: n=14) and quail housed in standard cages and exposed or not to the CSP (standard non-EE cages, control quail: n=12, CSP quail: n=16). Our procedure consisted of repeated aversive events (e.g. ventilators, delaying access to food, physical restraint, noise) presented two to five times per 24 h, randomly, for 15 days. During CSP, EE improved quail's welfare as their stereotypic pacing decreased and they rested more. CSP decreased exploration in all quail. After the end of CSP, quail presented increased emotional reactivity in emergence test. However, the effect of EE varied with test. Finally, chronic stress effects on comfort behaviours in the emergence test were alleviated by EE. These results indicate that EE can alleviate some aspects of behavioural alterations induced by CSP.


Assuntos
Criação de Animais Domésticos , Comportamento Animal , Coturnix/fisiologia , Meio Ambiente , Estresse Fisiológico , Ração Animal , Animais , Coturnix/crescimento & desenvolvimento , Medo , Feminino , Abrigo para Animais , Sistema Hipotálamo-Hipofisário/fisiologia , Masculino , Sistema Hipófise-Suprarrenal/fisiologia
6.
Poult Sci ; 92(11): 2811-26, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24135583

RESUMO

The objectives of this study were to 1) identify determinants of poor welfare in commercial broiler chicken flocks by studying the associations between selected resource-based measures (RBM, potential risk factors), such as litter quality and dark period, and animal-based welfare indicators (ABM), such as foot pad dermatitis and lameness, and 2) establish the breadth of effect of a risk factor by determining the range of animal welfare indicators associated with each of the risk factors (i.e., the number of ABM related to a specific RBM). Eighty-nine broiler flocks were inspected in 4 European countries (France, Italy, the United Kingdom, and the Netherlands) in a cross-sectional study. The ABM were contact dermatitis (measured using scores of foot-pad dermatitis and hock burn, respectively), lameness (measured as gait score), fear of humans (measured by the avoidance distance test and the touch test), and negative emotional state (measured using qualitative behavior assessment, QBA). In a first step, risk factors were identified by building a multiple linear regression model for each ABM. Litter quality was identified as a risk factor for contact dermatitis. Length of dark period at 3 wk old (DARK3) was a risk factor for the touch test result. DARK3 and flock age were risk factors for lameness, and the number of different stockmen and DARK3 were risk factors for QBA results. Next, the ABM were grouped according to risk factor and counted. Then, in a second step, associations between the ABM were investigated using common factor analysis. The breadth of a risk factor's effect was judged by combining the number (count) of ABM related to this factor and the strength of association between these ABM. Flock age and DARK3 appeared to affect several weakly correlated ABM, thus indicating a broad range of effects. Our findings suggest that manipulation of the predominant risk factors identified in this study (DARK3, litter quality, and slaughter age) could generate improvements in the related ABM and thereby enhance the birds' overall welfare status.


Assuntos
Bem-Estar do Animal , Galinhas/fisiologia , Emoções , Medo , Doenças das Aves Domésticas/epidemiologia , Criação de Animais Domésticos , Animais , Escuridão , Dermatite/epidemiologia , Dermatite/etiologia , Dermatite/veterinária , Europa (Continente)/epidemiologia , Pé/patologia , Doenças do Pé/epidemiologia , Doenças do Pé/etiologia , Doenças do Pé/veterinária , Abrigo para Animais , Coxeadura Animal/epidemiologia , Coxeadura Animal/etiologia , Doenças das Aves Domésticas/etiologia , Fatores de Risco
7.
Spinal Cord ; 51(10): 745-9, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23896667

RESUMO

STUDY DESIGN: Longitudinal cohort study. OBJECTIVES: Previously, the Van Lieshout hand function test for tetraplegia (short form)(VLT-SF) has been transformed into an interval scale (r_VLT-SF) using the Rasch analysis, thereby fulfilling the requirements of an objective measurement. The present study aims (1) to transform r_VLT-SFlogit scores (r_VLT-SFlogit) into 0-100 scores (r_VLT-SF100) in order to facilitate communication amongst its users and (2) to describe r_VLT-SF100 reference values in order to refine the prediction of upper extremity skilled performance in persons with tetraplegia. SETTING: Eight Dutch rehabilitation centres. METHODS: The VLT-SF data of tetraplegic patients from eight Dutch rehabilitation centres, gathered at the start of the active rehabilitation (t1), 3 months after t1 (t2) and at the time of discharge (t3), have been used. The r_VLT-SF100 total score for t1 and t3 were computed, anchored on the data for t2. Reference values (medians and interquartiles) for different subgroups were calculated at different moments during the rehabilitation. RESULTS: Data at t1 (n=64), t2 (n=73) and t3 (n=69) were used. The r_VLT-SFlogit scores (-4.78-6.32) were transformed into r_VLT-SF100 (0-100) at t2. Reference values were established for persons with motor complete or incomplete lesions with either a high (C1-C6) or a low (C7-T1) lesion level at t1, t2 and t3. Significant differences (P<0.025) in r_VLT-SF100 were found for most subgroups and different time intervals. CONCLUSIONS: The r_VLT-SFlogit scores were converted into r_VLT-SF100 scores, and reference values of the r_VLT-SF100 have been established for different subgroups of tetraplegic patients at different stages during rehabilitation. The r_VLT-SF100 has been proven to be able to detect improvement over time.


Assuntos
Quadriplegia/fisiopatologia , Quadriplegia/reabilitação , Traumatismos da Medula Espinal/fisiopatologia , Extremidade Superior/fisiopatologia , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Quadriplegia/diagnóstico , Quadriplegia/etiologia , Valores de Referência , Traumatismos da Medula Espinal/complicações
8.
Spinal Cord ; 51(10): 739-44, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23774127

RESUMO

STUDY DESIGN: Cross-sectional study. OBJECTIVE: The Van Lieshout hand function test for tetraplegia (VLT) measures the quality of arm-hand functioning in persons with tetraplegia. It is valid, reliable and responsive. However, it does not satisfy all the criteria for interval level measurement. The present study aims to apply the Rasch model to the VLT short form (VLT-SF) to upgrade its scale type towards interval level, and to verify if the requirements of an objective measure are satisfied in the revised version. SETTING: Eight Dutch Rehabilitation centres. METHODS: The VLT-SF data of 73 tetraplegic patients were Rasch-analysed (RUMM2030 software, RUMM Laboratory Pty Ltd, Perth, Australia) to verify the order of response categories, unidimensionality and reliability of the VLT-SF, and to assess its applicability regardless of (motor) lesion completeness. RESULTS: Seven of the ten VLT-SF items showed disordered response categories. The six original response categories were therefore recoded into three or four categories. After recoding, all items satisfied the model requirement of unidimensionality. The items were relatively well-targeted on the subjects' arm-hand skilled performance measures, leading to a good person separation index (R=0.91). The difficulty hierarchy of the VLT-SF items was invariant across patient subgroups of (motor) lesion completeness. CONCLUSIONS: Provided that response categories are recoded, VLT-SF Rasch analysis showed that the requirements of an objective measure were satisfied. This allows to compare the measurements of different patients quantitatively, and to follow their results over time.


Assuntos
Mãos/fisiopatologia , Quadriplegia/fisiopatologia , Quadriplegia/reabilitação , Traumatismos da Medula Espinal/fisiopatologia , Atividades Cotidianas , Adolescente , Adulto , Idoso , Estudos Transversais/métodos , Avaliação da Deficiência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Quadriplegia/etiologia , Traumatismos da Medula Espinal/complicações , Estatística como Assunto/métodos , Adulto Jovem
9.
Behav Brain Res ; 250: 299-303, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23711926

RESUMO

Compared to rodents, the relationship between anxiety and cognitive performances has been less studied in birds. Yet, birds are frequently exposed to stimulations that constitute a potential source of anxiety and can affect their adaptation to their living conditions. The present study was aimed at evaluating, in birds, the relationship between levels of anxiety and object habituation and discrimination with the use of Japanese quail lines divergently selected for a fear response, tonic immobility. Previous studies demonstrated that the selection programme has modified the general anxiety trait of the birds. The task consisted in 4 daily sessions of 8 successive presentations of the same object in the home cage of the quail in order to habituate each bird to the object. The observation that both quail with a high and a low anxiety trait progressively spent more time close to the object indicated that habituation occurred. Dishabituation was assessed during a single session of 8 presentations of a novel object. Only quail with a high anxiety trait exhibited significant discrimination. They spent significantly less time close to the novel object than to the habituated object. It is hypothesised that a high anxiety trait is associated with a more accurate processing of environmental cues or events resulting in better discriminative performances.


Assuntos
Ansiedade/genética , Ansiedade/fisiopatologia , Discriminação Psicológica/fisiologia , Habituação Psicofisiológica/fisiologia , Análise de Variância , Animais , Ansiedade/psicologia , Coturnix , Habituação Psicofisiológica/genética , Masculino
10.
Behav Brain Res ; 237: 124-8, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23000529

RESUMO

This study tested whether lines of Japanese quails divergently selected for a fear response, the tonic immobility, might constitute a reliable bird model for studying anxiety. Previous studies demonstrated that the selection modifies the general underlying emotionality of the birds rather than exerting its effect only on tonic immobility. The behavioural effects of intraperitoneal injections of diazepam, an anxiolytic drug, were assessed in two lines of quail selected either for their short (STI) or long (LTI) duration of tonic immobility. Effects of diazepam were examined in two tests used for measuring emotionality in birds, the open field and the tonic immobility tests. After being placed in the centre of the open field, birds with a high emotionality (LTI quails) stayed longer in the centre of the apparatus than STI quail. Diazepam had anxiolytic effect in LTI birds as it increased the time spent in the outer area. This effect of diazepam appears to be selective because the drug has no effect on other behaviours such as distress calls or escape attempts. The drug has also no effect on the tonic immobility response in any of the two lines. These findings reveal an "anxiogenic" trait of LTI birds in the open field test that can be modulated by the administration of an anxiolytic drug. Therefore quails selected for LTI and STI represent a valuable model to study the mechanisms underlying anxiety in birds.


Assuntos
Ansiolíticos/uso terapêutico , Ansiedade/tratamento farmacológico , Diazepam/uso terapêutico , Medo/efeitos dos fármacos , Análise de Variância , Animais , Ansiolíticos/farmacologia , Ansiedade/genética , Comportamento Animal/efeitos dos fármacos , Coturnix , Diazepam/farmacologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Comportamento Exploratório/efeitos dos fármacos , Feminino , Estatísticas não Paramétricas , Fatores de Tempo
11.
Br Poult Sci ; 53(3): 275-81, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22978583

RESUMO

1. Footpad dermatitis (FPD) is a recognised welfare problem in broiler chickens. Broiler feet (n = 54) were examined macroscopically and microscopically to determine a reliable correspondence between macroscopic and histological features, and to devise a scoring system that was relevant to bird welfare and easy to use at processing plants. 2. Three types of footpad lesion were defined based on their severity. Type I were mild lesions, visually characterised by scale enlargement and erythema, and histologically by hyperplasia and hyperkeratosis of the epidermis, superficial dermal congestion and oedema. Type II were moderate, superficial lesions, visually characterised by hypertrophic and hyperkeratotic scales covered with yellowish to brownish exudate, and histologically by a prominent pustular and crust-forming dermatitis. Type III lesions were the most pronounced, visually characterised by a thick dark adherent crust, and histologically by extensive ulceration. 3. On the basis of the severity and extent of these three types of lesions, a 5-point scale was devised, i.e. no or type I lesion (score 1), type II lesion (<50% or >50% of footpad, scores 2 and 3 respectively) and type III lesion (<50% or >50% of footpad, scores 4 and 5 respectively). 4. The scoring system has the advantage of making sense in terms of welfare compared with previous schemes. Furthermore, it is histologically validated and easy to use for the routine assessment of broiler welfare in processing plants.


Assuntos
Matadouros , Criação de Animais Domésticos , Dermatoses do Pé/veterinária , Doenças das Aves Domésticas/patologia , Coloração e Rotulagem/métodos , Bem-Estar do Animal , Animais , Galinhas , Dermatoses do Pé/epidemiologia , Dermatoses do Pé/patologia , Doenças das Aves Domésticas/epidemiologia , Prevalência , Índice de Gravidade de Doença , Coloração e Rotulagem/veterinária
12.
J Colloid Interface Sci ; 371(1): 150-8, 2012 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-22284449

RESUMO

Nowadays, titanium is a very commonly used biomaterial for the preparation of orthopedic and dental implants. Its excellent mechanical and biochemical bulk properties are nevertheless counterbalanced by its propensity to long term degradation in physiological conditions and its weak osseointegrative capacities. In this context, surface modifications can significantly hinder titanium weaknesses. The approach considered in this work relies on the preparation of thin composite coatings based on tantalum oxide and carbon nanotubes by sol-gel process. Tantalum is particularly interesting for its high biocompatibility and bioactivity, as well as its strong resistance to bio-corrosion. Carbon nanotubes are exploited to reinforce the compactness and homogeneity of the coatings, and can act as a favorable factor to strengthen the interaction with bone components by biomimicry. The composite layers are further modified with specific organophosphonic acid molecular films, able to chemically bind the tantalum oxide surface and improve the hydroxyapatite formation process. The characteristics and the qualities of these hybrid inorganic/organic coatings are evaluated by XPS, SEM, TEM, peeling tests, contact angle measurements, and electrochemical characterizations (free potential, polarization curves).


Assuntos
Materiais Biocompatíveis/química , Durapatita/química , Nanotubos de Carbono/química , Organofosfonatos/metabolismo , Compostos Organofosforados/química , Óxidos/química , Tantálio/química , Titânio/química , Materiais Biocompatíveis/metabolismo , Durapatita/metabolismo , Teste de Materiais , Compostos Organofosforados/metabolismo , Óxidos/metabolismo , Transição de Fase , Propriedades de Superfície , Tantálio/metabolismo , Titânio/metabolismo
13.
J Anim Sci ; 90(6): 2003-13, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22205669

RESUMO

Because of the increasing demand for raw cuts and processed products, there is a trend to producing very heavy broilers. Breeds that are used for such kinds of production have been intensively selected for growth rate and breast meat yield, and birds are reared for a longer period than standard broilers. This study was to evaluate the effects of increasing slaughter age on technical and economic factors, including production efficiency and environmental costs, bird welfare, and breast meat quality in a modern heavy broiler line. Five groups of 300 male Ross 708 chickens were reared until slaughter ages of 35, 42, 49, 56, or 63 d. Increasing age at slaughter from 35 to 63 d resulted in a 7.4-fold increase (P < 0.01) in mortality rate (5.21 vs. 0.70%). It also increased (P < 0.001) the slaughter weight and ADFI of birds 2.5- and 1.4-fold, respectively, without affecting their G:F. Under our experimental conditions, economic profit evaluated through the net gain reached a maximum at 42 d. The moisture and ammonium content of litter increased (P < 0.05 and P < 0.01, respectively) rapidly during rearing concomitantly with increased (P < 0.05) occurrence and severity of contact dermatitis and decreased (P < 0.05) walking ability and activity of birds. Thermal comfort also decreased (P < 0.05) greatly as early as 42 d of age. Changes in carcass quality occurred mainly between 35 and 56 d of age, with a progressive increase (P < 0.001) in breast and leg yield, whereas body fatness was barely affected by age. Major changes in breast meat traits were observed between 35 and 49 d of age, with an increase in muscle pH at 15 min (P < 0.01) and 24 h (P < 0.001) postmortem and reduced (P < 0.001) lightness and drip loss. The protein and lipid content of raw breast meat also increased (P < 0.05 and P < 0.01, respectively) with age. Taking into account the main aspects of sustainability, we could recommend slaughtering chickens of heavy line at 42 d of age.


Assuntos
Envelhecimento , Criação de Animais Domésticos/economia , Criação de Animais Domésticos/métodos , Bem-Estar do Animal/normas , Carne/normas , Animais , Composição Corporal , Galinhas , Masculino
14.
Behav Brain Res ; 225(2): 505-10, 2011 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-21871499

RESUMO

There is considerable variability in the susceptibility of individuals to the adverse effects of chronic stress. In humans and other mammals, individual traits such as high anxiety are proposed as a vulnerability factor for the development of stress-related disorders. In the present study, we tested whether a similar behavioural trait in birds, higher emotional reactivity, also favours the occurrence of chronic stress-related behavioural and physiological dysfunction. For this, lines of Japanese quail divergently selected for a typical fear response in birds, the duration of tonic immobility, were subjected to unpredictable aversive stimulation over 2 weeks. Previous studies demonstrate that the selection program modifies the general underlying emotionality of the birds rather than exerting its effect only on tonic immobility. Interestingly, only birds selected for their higher emotionality exhibited significantly enhanced latency to first step and decreased locomotor activity in the open-field test after exposure to chronic stress compared to non-stressed control birds. This effect of chronic stress was selective for the tested dimension of bird emotional reactivity because there was no observed effect on the tonic immobility response. Moreover, chronically stressed birds selected for their higher emotionality exhibited significantly decreased basal corticosterone levels, a physiological marker of stress. These findings show that chronic stress is associated with changes in emotional reactivity and related physiological markers in birds. They also highlight emotional reactivity as an important predisposing factor for the occurrence of the adverse effects of chronic stress in birds.


Assuntos
Coturnix/genética , Medo/psicologia , Seleção Genética/fisiologia , Estresse Psicológico/psicologia , Animais , Peso Corporal/fisiologia , Corticosterona/sangue , Coturnix/sangue , Coturnix/fisiologia , Medo/fisiologia , Feminino , Resposta de Imobilidade Tônica/fisiologia , Atividade Motora , Estresse Psicológico/sangue , Estresse Psicológico/fisiopatologia
15.
J Colloid Interface Sci ; 344(2): 390-4, 2010 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-20122696

RESUMO

The development of new biomaterials is one of the most challenging tasks in material science. Metals and particularly titanium and its alloys are widely used because of their good corrosion resistance, mechanical properties and biocompatibility. However, the toxicity of alloys, long term degradation in body fluids and risks of loosening are still problematic. To increase the corrosion resistance of the material and reduce ion release, our interest focused on tantalum, another metal well known for its excellent biocompatibility and resistance to bio-corrosion. These very good properties make tantalum a metal of interest for biomaterials but its high cost and high density disqualify it for use as bulk material. In this paper, we propose to combine the good bulk properties of titanium with the excellent surface properties of tantalum by using sol-gel deposition of a tantalum oxide layer on bare titanium. Furthermore, as orthopedics implants are part of our long term goals, we report on the formation of a composite layer of tantalum oxide and multiwalled carbon nanotubes (MWCNTs). MWCNTs have been shown to have promising properties in contact with bone and bone cells and could strengthen the implant. Characterizations are performed using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM).


Assuntos
Materiais Biocompatíveis/química , Membranas Artificiais , Nanotubos de Carbono/química , Óxidos/química , Tantálio/química , Tamanho da Partícula , Espectrofotometria , Propriedades de Superfície , Raios X
16.
Br Poult Sci ; 50(4): 407-17, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19735009

RESUMO

1. This slaughterhouse-based study was to evaluate correlations between cutaneous lesions which are linked to animal welfare. The relationships between these lesions and various rearing factors were investigated. 2. The percentage of lesions in each flock was determined by observation at the slaughterhouse. Fifty-five flocks slaughtered between May 2005 and May 2006 in 8 slaughterhouses were investigated. 3. Data relating to farm management and housing factors during the rearing period were collected retrospectively from 36 of the 55 flocks scored for lesions. 4. A negative correlation was observed between (i) presence of breast blisters and deep hock burns, (ii) presence of breast blisters and deep footpad dermatitis, and (iii) presence of breast burns and scratches. 5. We proposed an assessment of broiler chicken welfare at the slaughterhouse on the basis of several criteria: (i) footpad dermatitis, hock burns and breast burns, (ii) scratches, and (iii) breast blisters. 6. The presence of contact dermatitis was related to litter quality and several management factors. Only scratches and breast blisters were related to high stocking density. The type of lesion was related to genotype. Genotype A (fast-growing) had fewer breast blisters but deeper footpad lesions than B (slower-growing).


Assuntos
Matadouros , Criação de Animais Domésticos/métodos , Doenças das Aves Domésticas/epidemiologia , Dermatopatias/veterinária , Bem-Estar do Animal , Animais , Galinhas/genética , Dermatoses do Pé/epidemiologia , Dermatoses do Pé/etiologia , Dermatoses do Pé/veterinária , França , Genótipo , Abrigo para Animais , Doenças das Aves Domésticas/classificação , Doenças das Aves Domésticas/etiologia , Estudos Retrospectivos , Dermatopatias/epidemiologia , Dermatopatias/etiologia
17.
J Colloid Interface Sci ; 336(2): 497-503, 2009 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-19481760

RESUMO

Titanium and its alloys are widely used in surgical implants due to their appropriate properties like corrosion resistance, biocompatibility, and load bearing. Unfortunately when metals are used for orthopedic and dental implants there is the possibility of loosening over a long period of time. Surface modification is a good way to counter this problem. A thin tantalum oxide layer obtained by layer-by-layer (LBL) sol-gel deposition on top of a titanium surface is expected to improve biocorrosion resistance in the body fluid, biocompatibility, and radio-opacity. This elaboration step is followed by a modification of the tantalum oxide surface with an organodiphosphonic acid self-assembled monolayer, capable of chemically binding to the oxide surface, and also improving hydroxyapatite growth. The different steps of this proposed process are characterized by surfaces techniques like contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM).


Assuntos
Materiais Revestidos Biocompatíveis/química , Organofosfonatos/química , Compostos Organofosforados/química , Óxidos/química , Tantálio/química , Titânio/química , Durapatita , Transição de Fase , Propriedades de Superfície
18.
Dev Psychobiol ; 51(4): 311-21, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19277976

RESUMO

A simultaneous two-choice test was used to investigate discrimination between a familiar (F) and an unfamiliar conspecific (U) in Japanese quail, selected for high (HSR) or low (LSR) social reinstatement behavior (tendency to rejoin and stay close to conspecifics). Animals were 1-week unsexed and 6-week-old male quail. One-week-old LSR quail and 6-week-old male HSR quail displayed discrimination after 24 hr of pair contact (p < 0.05), and a tendency to discriminate (p < 0.10) was found in adult male LSR quail. After 1 week of pair contact, results were similar in LSR quail chicks, but no discrimination was evidenced in adult quail of either line. Therefore, Japanese quail are able to discriminate between a familiar cagemate and an unfamiliar conspecific after only 24 hr of pair contact. Moreover, this study reveals for the first time in this species that social motivation and age both influence the display of individual discrimination.


Assuntos
Coturnix , Aprendizagem por Discriminação , Motivação , Comportamento Social , Fatores Etários , Animais , Masculino , Meio Social
19.
Mol Plant Microbe Interact ; 21(2): 232-43, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18184067

RESUMO

Sulfated laminarin (PS3) has been shown previously to be an elicitor of plant defense reactions in tobacco and Arabidopsis and to induce protection against tobacco mosaic virus. Here, we have demonstrated the efficiency of PS3 in protecting a susceptible grapevine cultivar (Vitis vinifera cv. Marselan) against downy mildew (Plasmopara viticola) under glasshouse conditions. This induced resistance was associated with potentiated H2O2 production at the infection sites, upregulation of defense-related genes, callose and phenol depositions, and hypersensitive response-like cell death. Interestingly, similar responses were observed following P. viticola inoculation in a tolerant grapevine hybrid cultivar (Solaris). A pharmacological approach led us to conclude that both callose synthesis and jasmonic acid pathway contribute to PS3-induced resistance.


Assuntos
Glucanos/farmacologia , Imunidade Inata/efeitos dos fármacos , Imunidade Inata/imunologia , Oomicetos/fisiologia , Doenças das Plantas/imunologia , Vitis/imunologia , Vitis/microbiologia , Morte Celular/efeitos dos fármacos , Ciclopentanos/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Peróxido de Hidrogênio/metabolismo , Oomicetos/citologia , Oomicetos/crescimento & desenvolvimento , Oomicetos/ultraestrutura , Oxilipinas/farmacologia , Doenças das Plantas/microbiologia , Folhas de Planta/citologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/microbiologia , Folhas de Planta/ultraestrutura , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/microbiologia , Estômatos de Plantas/ultraestrutura , Esporos/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Vitis/citologia , Vitis/genética
20.
Behav Processes ; 77(3): 313-9, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17720332

RESUMO

Most tests used to study fear in birds involve transferring them to a novel environment, which constitutes a bias in studies aiming at identifying the neural correlates of a specific fear-inducing situation. In order to investigate fear in birds with minimum interference by humans, behavioural and endocrine responses to the presentation of a novel object in the home cage were investigated in two lines of Japanese quail divergently selected for long or short duration of tonic immobility, a behavioural index of fear. Presentation of the novel object induced typical fear responses (avoidance of the object, increased pacing and increased plasma corticosterone levels) that were similar in the two lines of quail. Presentation of a novel object in the home cage thus appears to be a suitable stimulus to induce fear reactions in quail, with minimum interference from other motivational systems. The fact that quail of both lines reacted similarly in this test, while they are known to differ greatly in their behavioural responses to other fear-inducing tests, illustrates the multidimensional nature of fear.


Assuntos
Corticosterona/sangue , Comportamento Exploratório/fisiologia , Medo/fisiologia , Resposta de Imobilidade Tônica/fisiologia , Estresse Psicológico/sangue , Adaptação Fisiológica , Animais , Animais Endogâmicos , Coturnix , Reação de Fuga/fisiologia , Abrigo para Animais , Masculino , Seleção Genética , Método Simples-Cego , Especificidade da Espécie , Estatísticas não Paramétricas
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