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1.
J Hum Nutr Diet ; 31(6): 781-784, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29882336

RESUMO

BACKGROUND: Cancer cachexia is a multifactorial syndrome characterised by a progressive loss of skeletal muscle mass. It adversely influences quality of life, treatment response and survival. Early identification and multimodal interventions can potentially treat cancer cachexia. However, healthcare professionals demonstrate a lack of understanding and the ability to identify cancer cachexia early. The present study aimed to evaluate the assessment by physicians of nutritional status in cancer patients admitted to hospice. METHODS: A retrospective medical record review was conducted on all cancer admissions to a specialist in-patient palliative care unit over a 4-month period between October 2016 and January 2017. Charts were reviewed for evidence of documented nutritional assessment by physicians. Data were collected from the referral letter, admission notes, drug kardex and discharge letter. The information extracted included: (i) patient demographics and characteristics; (ii) terms used by physicians to describe nutritional status; (iii) any record of nutritional impact symptoms (NIS) experienced by the patient; and (iv) nutritional interventions prescribed. RESULTS: One hundred and forty admissions were evaluated. Nutritional terminology and NIS were most commonly documented on the admission notes. Only 41% of documents recorded any nutritional term used by physicians to assess nutritional status. Furthermore, 71% of documents recorded at least one NIS experienced by the patient. Fatigue was the most frequent NIS. CONCLUSIONS: We identified an inadequate nutritional assessment of cancer patients admitted to hospice. Implementation of a nutritional symptom checklist and nutrition screening tools, along with enhanced physician education and multidisciplinary nutrition care, could improve the identification and management of cancer cachexia in the palliative care setting.


Assuntos
Caquexia/diagnóstico , Neoplasias/complicações , Avaliação Nutricional , Estado Nutricional , Cuidados Paliativos , Médicos , Qualidade da Assistência à Saúde , Adulto , Idoso , Idoso de 80 Anos ou mais , Caquexia/complicações , Caquexia/terapia , Competência Clínica , Documentação , Fadiga/diagnóstico , Fadiga/etiologia , Feminino , Hospitais para Doentes Terminais , Hospitalização , Humanos , Masculino , Programas de Rastreamento , Prontuários Médicos , Pessoa de Meia-Idade , Terapia Nutricional , Qualidade de Vida , Estudos Retrospectivos
2.
Sci Rep ; 10(1): 9246, 2020 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-32514003

RESUMO

An apparent and common feature of aposematic patterns is that they contain a high level of achromatic (luminance) contrast, for example, many warning signals combine black spots and stripes with a lighter colour such as yellow. However, the potential importance of achromatic contrast, as distinct from colour contrast, in reducing predation has been largely overlooked. Here, using domestic chicks as a model predator, we manipulated the degree of achromatic contrast in warning patterns to test if high luminance contrast in aposematic signals is important for deterring naïve predators. We found that the chicks were less likely to approach and eat prey with high contrast compared to low contrast patterns. These findings suggest that aposematic prey patterns with a high luminance contrast can benefit from increased survival through eliciting unlearned biases in naïve avian predators. Our work also highlights the importance of considering luminance contrast in future work investigating why aposematic patterns take the particular forms that they do.

3.
AJNR Am J Neuroradiol ; 38(1): 2-9, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27561833

RESUMO

Third window abnormalities are defects in the integrity of the bony structure of the inner ear, classically producing sound-/pressure-induced vertigo (Tullio and Hennebert signs) and/or a low-frequency air-bone gap by audiometry. Specific anatomic defects include semicircular canal dehiscence, perilabyrinthine fistula, enlarged vestibular aqueduct, dehiscence of the scala vestibuli side of the cochlea, X-linked stapes gusher, and bone dyscrasias. We discuss these various entities and provide key examples from our institutional teaching file with a discussion of symptomatology, temporal bone CT, audiometry, and vestibular-evoked myogenic potentials.


Assuntos
Orelha Interna/patologia , Doenças do Labirinto/patologia , Humanos
4.
Circulation ; 101(15): 1812-8, 2000 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-10769282

RESUMO

BACKGROUND: Dilated cardiomyopathy (DCM) and sensorineural hearing loss (SNHL) are prevalent disorders that occur alone or as components of complex multisystem syndromes. Multiple genetic loci have been identified that, when mutated, cause DCM or SNHL. However, the isolated coinheritance of these phenotypes has not been previously recognized. METHODS AND RESULTS: Clinical evaluations of 2 kindreds demonstrated autosomal-dominant transmission and age-related penetrance of both SNHL and DCM in the absence of other disorders. Moderate-to-severe hearing loss was evident by late adolescence, whereas ventricular dysfunction produced progressive congestive heart failure after the fourth decade. DNA samples from the larger kindred (29 individuals) were used to perform a genome-wide linkage study. Polymorphic loci on chromosome 6q23 to 24 were coinherited with the disease (maximum logarithm of odds score, 4.88 at locus D6S2411). The disease locus must lie within a 2.8 cM interval between loci D6S975 and D6S292, a location that overlaps an SNHL disease locus (DFNA10). However, DFNA10 does not cause cardiomyopathy. The epicardin gene, which encodes a transcription factor expressed in the myocardium and cochlea, was assessed as a candidate gene by nucleotide sequence analysis; no mutations were identified. CONCLUSIONS: A syndrome of juvenile-onset SNHL and adult-onset DCM is caused by a mutation at 6q23 to 24 (locus designated CMD1J). Recognition of this cardioauditory disorder allows for the identification of young adults at risk for serious heart disease, thereby enabling early intervention. Definition of the molecular cause of this syndrome may provide new information about important cell physiology common to both the ear and heart.


Assuntos
Cardiomiopatia Dilatada/genética , Cromossomos Humanos Par 6/genética , Perda Auditiva Neurossensorial/genética , Mutação , Adulto , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Proteínas de Ligação a DNA/genética , Feminino , Genes Dominantes , Ligação Genética , Humanos , Masculino , Linhagem , Penetrância , Síndrome , Fatores de Transcrição/genética
5.
Scr Med (Brno) ; 78(2): 75-82, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-19018290

RESUMO

The case report presented herein aims at promoting the awareness in medical, notably cardiological, practice of the importance of, first, collecting at least a week-long record of around-the-clock measurements of blood pressure (BP) and heart rate (HR) (and a much longer record if the 7 day record so indicates) and, second, of analysing the data chronobiologically in the light of reference values specified as a function of time, gender and age as a minimum. In addition to diagnosing deviations in a chronome (time structure)-adjusted mean value, a chronobiological approach identifies abnormalities in the variability of BP and/or HR, gauged by the circadian characteristics (double amplitude and acrophase, measures of the extent and timing of predictable change within a cycle) and by the standard deviation. A woman in presumably good health was 60 years of age at the start of intermittent monitoring over a 7 year span. The case report illustrates the extent to which a decision based on single BP readings and even on 24 hour averages may be misleading. Treatment based on an initial week-long monitoring may benefit from continued long-term monitoring.

6.
Gene ; 178(1-2): 205-7, 1996 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-8921917

RESUMO

Three laccase-encoding cDNAs were cloned from a tobacco stem cDNA library. One of them contains a full length sequence coding for a cationic laccase. The predicted polypeptide sequence shows 48% identity with sycamore laccase. Amino acid comparisons with other laccases and ascorbate oxidases have shown that this new plant laccase sequence also contains four potential copper binding regions which are highly conserved among the blue copper oxidases.


Assuntos
Nicotiana/enzimologia , Oxirredutases/genética , Plantas Tóxicas , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , DNA de Plantas , Lacase , Dados de Sequência Molecular , Nicotiana/genética
7.
Pediatr Infect Dis J ; 14(2): 93-6, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7746714

RESUMO

Bacterial meningitis, particularly that resulting from Streptococcus pneumoniae, is a common cause of acquired profound sensorineural deafness in children. The pathogenesis of meningogenic hearing loss has been investigated in an experimental rabbit model. In this study significant deafness was documented within the first 15 hours of infection. Initiation of antibiotic therapy at this time diminished the severity of hearing loss in most animals. The addition of dexamethasone to antibiotic therapy prevented the development of profound deafness. These results suggest this model will be useful in developing antiinflammatory strategies to improve the outcome of bacterial meningitis.


Assuntos
Dexametasona/uso terapêutico , Perda Auditiva Neurossensorial/prevenção & controle , Meningite Pneumocócica/tratamento farmacológico , Animais , Ceftriaxona/administração & dosagem , Ceftriaxona/uso terapêutico , Dexametasona/administração & dosagem , Modelos Animais de Doenças , Quimioterapia Combinada , Potenciais Evocados Auditivos , Feminino , Perda Auditiva Neurossensorial/tratamento farmacológico , Perda Auditiva Neurossensorial/etiologia , Modelos Lineares , Meningite Pneumocócica/complicações , Coelhos
8.
Vet Microbiol ; 8(1): 35-43, 1983 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-6405539

RESUMO

Newborn calves inoculated with rotavirus, enterotoxigenic Escherichia coli (ETEC) serotype 020:K' x 106':K99:HNM, either alone or in combination, became depressed, anorectic, diarrhoeic and dehydrated. ETEC did not adhere to the intestine although there was extensive proliferation in the lumen. Only slight mucosal changes were induced by ETEC and the activity of membrane bound lactase remained normal. More severe mucosal damage and a decrease in lactase activity were found in newborn calves inoculated with either rotavirus or rotavirus and ETEC in combination. The most severe clinical illness was found in calves inoculated with both rotavirus and ETEC. Calves inoculated at 1 week of age with either rotavirus or ETEC remained clinically normal. Rotavirus infection produced slight mucosal changes and a reduction of lactase activity. In contrast, colostrum-fed or suckling calves up to 2 weeks old inoculated with both rotavirus and ETEC became clinically affected, showed severe mucosal damage and decreased lactase activity. There was no bacterial adhesion to the intestinal mucosa as observed by immunofluorescent labelling and light microscopy.


Assuntos
Doenças dos Bovinos/fisiopatologia , Diarreia/veterinária , Infecções por Escherichia coli/veterinária , Intestinos/fisiopatologia , Infecções por Rotavirus/veterinária , Animais , Bovinos , Doenças dos Bovinos/patologia , Diarreia/patologia , Diarreia/fisiopatologia , Enterotoxinas/biossíntese , Infecções por Escherichia coli/fisiopatologia , Imunofluorescência , Intestinos/enzimologia , Intestinos/patologia , Infecções por Rotavirus/fisiopatologia , beta-Galactosidase/metabolismo
9.
Laryngoscope ; 101(12 Pt 1): 1285-92, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1766298

RESUMO

Clinical studies of predisposing factors in the development of hearing loss secondary to bacterial meningitis have produced conflicting results. An animal model of meningogenic labyrinthitis was developed for more precise study of these parameters. Rabbits were inoculated intrathecally with 10(5) pneumococci to induce meningitis. Hearing thresholds were measured using auditory-evoked responses to 1 kHz, 10 kHz, and click stimuli before infection and every 12 hours thereafter. Profound deafness occurred in all subjects at an average of 48 hours following infection. The incidence and severity of hearing loss was strongly correlated with the duration of meningitis. Temporal bone histology revealed acute inflammation of all perilymphatic spaces including the cochlear aqueduct. This model demonstrated that the risk and severity of hearing loss increase with the duration of meningitis and suggested that the cochlear aqueduct is an anatomic pathway for the extension of infection from the cerebrospinal fluid to the cochlea. The implications for therapy in humans is discussed.


Assuntos
Perda Auditiva Neurossensorial/etiologia , Meningite Pneumocócica/complicações , Estimulação Acústica , Animais , Limiar Auditivo/fisiologia , Aqueduto da Cóclea/patologia , Doenças Cocleares/etiologia , Doenças Cocleares/patologia , Ducto Coclear/patologia , Surdez/etiologia , Surdez/fisiopatologia , Modelos Animais de Doenças , Potenciais Evocados Auditivos/fisiologia , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Audição/fisiologia , Perda Auditiva Neurossensorial/patologia , Perda Auditiva Neurossensorial/fisiopatologia , Labirintite/etiologia , Labirintite/patologia , Meningite Pneumocócica/patologia , Neutrófilos/patologia , Coelhos , Rampa do Tímpano/patologia , Osso Temporal/patologia , Fatores de Tempo
10.
Arch Otolaryngol Head Neck Surg ; 116(2): 197-201, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2297414

RESUMO

Bilateral deafness can occur in patients with Menière's disease who have undergone a labyrinthectomy in one ear. To investigate the feasibility of a cochlear implant in the labyrinthectomized ear, promontory electrical testing by transtympanic needle was performed in six patients who had undergone a unilateral transmastoid labyrinthectomy 6 weeks to 5 years previously. All patients had a behavioral response to the stimulus, and each described a different pitch percept with the four frequencies used. Five of the patients demonstrated an electrically evoked middle latency response. These data are comparable with behavioral and electrophysiologic responses from ears deafened by other causes and now successfully implanted. The results suggest that peripheral neural elements and central auditory pathways remain at least partially functional many years after a labyrinthectomy. Thus, a labyrinthectomy should not be withheld as a surgical option if otherwise indicated.


Assuntos
Orelha Interna/cirurgia , Potenciais Evocados Auditivos/fisiologia , Doença de Meniere/fisiopatologia , Adulto , Implantes Cocleares , Estimulação Elétrica , Feminino , Humanos , Masculino , Doença de Meniere/cirurgia , Pessoa de Meia-Idade , Tempo de Reação
11.
Arch Otolaryngol Head Neck Surg ; 127(6): 629-36, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11405860

RESUMO

BACKGROUND: Deafness and handicapping sensorineural hearing impairment occur frequently in neonatal intensive care unit survivors for unknown reasons. PATIENTS AND METHODS: Hearing was tested early and repeatedly in neonatal intensive care unit patients with an auditory brainstem response (ABR) screener. The temporal bones of 15 nonsurvivors (30 ears) were fixed promptly (average, 5 hours) after death for histological evaluation. RESULTS: Among these patients, 12 failed the ABR screen bilaterally, 1 passed unilaterally, and 2 passed bilaterally. Cochlear histopathologic conditions that could contribute to hearing loss included bilateral selective outer hair cell loss in 2 patients, bilateral selective inner hair cell loss in 3 (all premature), and a combination of both outer and inner hair cell loss in 2. Other hair cell abnormalities were noted; the 2 infants who had passed the ABR screen demonstrated normal histological features. Neuronal counts were normal. CONCLUSIONS: Auditory brainstem response failure among these neonatal intensive care unit infants who died was extremely common in part owing to an unexpected histological alteration, selective inner hair cell loss among premature newborns, that should be detectable uniquely by the ABR testing method. Additional histological patterns suggest more than one cause for neonatal intensive care unit hearing loss. Hair cell loss patterns seem frequently compatible with in utero damage.


Assuntos
Cóclea/patologia , Células Ciliadas Auditivas Internas/patologia , Células Ciliadas Auditivas Externas/patologia , Doenças do Prematuro/patologia , Feminino , Perda Auditiva Neurossensorial/patologia , Perda Auditiva Neurossensorial/fisiopatologia , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal , Masculino
12.
Vet Parasitol ; 11(2-3): 121-6, 1982 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-6819679

RESUMO

Twelve gnotobiotic piglets were dosed with a bacteria-free calf faecal homogenate which contained Cryptosporidium oocysts. The infection induced severe enterocolitis in piglets when inoculated at 1 day of age, moderate diarrhoea at 7 days of age and a subclinical infection at 15 days of age. In piglets aged 3 days or less, the entire intestine was extensively infected with Cryptosporidium and the mucosa was severely damaged. In piglets 7 days of age or older, the upper small intestine was sparsely infected with the organisms, but the ileum and the large bowel were heavily infected with associated mucosal damage.


Assuntos
Coccidiose/veterinária , Colite/veterinária , Intestinos/parasitologia , Doenças dos Suínos/parasitologia , Envelhecimento , Animais , Animais Recém-Nascidos , Coccídios/ultraestrutura , Coccidiose/parasitologia , Colite/parasitologia , Suscetibilidade a Doenças , Vida Livre de Germes , Mucosa Intestinal/parasitologia , Mucosa Intestinal/patologia , Suínos , beta-Galactosidase/metabolismo
13.
Res Vet Sci ; 37(2): 249-51, 1984 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6438747

RESUMO

Plasma vitamin B12 concentrations in cattle were analysed by a radioisotope dilution assay using pig intrinsic factor and a microbiological assay using Euglena gracilis. Both assays provided similar results for samples of cattle plasma containing vitamin B12 concentrations ranging from 0.07 to 3.60 micrograms litre-1 (r = 0.95, P less than 0.001). The addition of excess cobinamide in the radioisotope dilution assay to block non-specific binding in the intrinsic factor preparation due to the presence of R-type binders, was used to determine the presence of cobalamin analogues. Cobalamin analogues accounted for up to 50 per cent of the total vitamin B12 concentration in samples of plasma from cows but were virtually undetectable in plasma from sheep.


Assuntos
Bovinos/sangue , Vitamina B 12/sangue , Ração Animal , Animais , Bioensaio , Doenças dos Bovinos/diagnóstico , Cobalto/administração & dosagem , Cobalto/deficiência , Radioisótopos de Cobalto , Cobamidas/farmacologia , Euglena gracilis , Feminino , Técnica de Diluição de Radioisótopos/veterinária , Ovinos/sangue , Vitamina B 12/análogos & derivados
14.
J Am Acad Audiol ; 5(6): 417-25, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7858304

RESUMO

Eight audiology students with little or no visual reinforcement audiometry (VRA) experience each performed a VRA test on an infant. Four of the students received approximately 5 hours of behavioral audiometry simulator (BAS) training, and 1 week later, after the first VRA test, all eight students tested a second infant. Student performance was rated by three audiologists who were experienced in performing VRA with infants. The performance of the group that received BAS training improved significantly while the performance of the control group did not. Among the students who received BAS training, those who improved the most during stimulated testing also showed the greatest improvement in VRA with real infants.


Assuntos
Audiologia/educação , Audiometria , Estimulação Luminosa , Feminino , Transtornos da Audição/diagnóstico , Humanos , Lactente , Masculino , Pediatria
15.
Vet Rec ; 112(6): 116-20, 1983 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-6220509

RESUMO

Twenty-two calves between one and 20 days old were infected orally or by contact with cryptosporidia. Calves were maintained as either specific pathogen free, colostrum fed or sucking and were inoculated with either a bacteria free or a contaminated cryptosporidium preparation. Enteritis was characterised by depression, anorexia and diarrhoea and cryptosporidium oocysts were excreted during the clinical course of the illness. In the initial stages of the disease, cryptosporidium infestation was found throughout the small intestine; in the later stage the large intestine was also affected. Villous atrophy and fusion was present at small intestinal sites infected with cryptosporidia and lactase levels were depressed. No lesions were seen in infected large intestinal mucosa. Although the incubation period was longest (five to seven days) in calves infected by contact, there were few differences in the clinical course of disease or the pathological findings between any of the infected calves.


Assuntos
Doenças dos Bovinos/diagnóstico , Coccidiose/veterinária , Animais , Animais Lactentes , Bovinos , Doenças dos Bovinos/etiologia , Doenças dos Bovinos/patologia , Coccidiose/diagnóstico , Coccidiose/patologia , Colostro , Diarreia/diagnóstico , Diarreia/patologia , Diarreia/veterinária , Enterite/diagnóstico , Enterite/patologia , Enterite/veterinária , Íleo/patologia , Organismos Livres de Patógenos Específicos
16.
Aust Vet J ; 52(10): 438-41, 1976 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-189746

RESUMO

Measurements of villus/crypt length ratio and mucosal beta-galactosidase activity were made on calves less than 3 weeks of age which had diarrhoea associated with reovirus-like agent and E. coli. In calves with diarrhoea, the villus/crypt length ratios at all sites examined along the small intestine were less than in normal calves of similar age. This was attributed to a reduction in length of vili in calves infected with the reovirus-like agent. The activity of mucosal beta-galactosidase in the intestine of calves with diarrhoea was less than in normal calves, at all sites examined. A relationship existed between beta-galactosidase activity in vitro and lactose hydrolysis in vivo. It was concluded that calves with diarrhoea associated with reovirus-like agent, have a reduced ability to utilize dietary lactose.


Assuntos
Animais Recém-Nascidos , Doenças dos Bovinos/patologia , Infecções por Escherichia coli/veterinária , Intestino Delgado/patologia , Infecções por Reoviridae/veterinária , Animais , Bovinos , Doenças dos Bovinos/enzimologia , Infecções por Escherichia coli/enzimologia , Infecções por Escherichia coli/patologia , Galactosidases/metabolismo , Intestino Delgado/enzimologia , Infecções por Reoviridae/enzimologia , Infecções por Reoviridae/patologia
17.
Aust Vet J ; 59(3): 93-5, 1982 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6760849

RESUMO

Three strains of enterotoxigenic Escherichia coli (ETEC) (064:KSNT, K88ac; 020:KSNT, K88ac and 08:K85ab, K99) originally cultured from outbreaks of diarrhoea in piglets a few hours old, were administered orally to gnotobiotic piglets. There was a marked age-related difference in the clinical response to infection between the 3 strains although they all produced heat-stable toxin. All 3 strains produced severe clinical signs of depression, anorexia, vomiting, diarrhoea, followed by dehydration and death in one-day-old piglets. In piglets infected at 3 days of age the two K88+ ETEC caused diarrhoea and death but the K99+ ETEC induced moderate diarrhoea only. In piglets infected at 7 days of age, the 064 strain produced severe diarrhoea and death, and 020 strain caused mild diarrhoea in 3 of 6 piglets with one death while the 08 strain caused no illness. Pathological changes in the intestinal tract associated with these infections were minimal, or absent. Immunofluorescent staining with homologous hyperimmune sera demonstrated adherence of the 3 ETEC strains to the brush border of small intestinal epithelial cells. Fluorescing organisms were observed in all infected piglets irrespective of the severity of clinical signs but the degree and extent of colonisation varied with the age of the piglets and the infecting strain. This may explain the difference in clinical response between the 3 strains.


Assuntos
Enterotoxinas/biossíntese , Infecções por Escherichia coli/veterinária , Escherichia coli/metabolismo , Doenças dos Suínos/microbiologia , Animais , Animais Recém-Nascidos , Diarreia/microbiologia , Diarreia/patologia , Diarreia/veterinária , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/patologia , Vida Livre de Germes , Intestino Delgado/patologia , Especificidade da Espécie , Suínos , Doenças dos Suínos/patologia
18.
Aust Vet J ; 56(4): 160-7, 1980 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7436915

RESUMO

The selenium nutrition of sheep throughout Victoria was assessed by a survey of the blood glutathione peroxidase activity in 708 flocks. It was shown that the blood glutathione peroxidase activity in sheep had a seasonal variation with lowest levels in the spring. The enzyme activity was correlated with the blood selenium concentration. Areas where blood selenium was less than 0.03 micrograms/ml in spring were defined. Sheep with low selenium nutrition were grazing pastures in the high rainfall areas on acid soils, particularly those derived from granite. Selenium concentrations in pasture samples examined were greater than 0.02 mg/kg, and it was found that superphosphate application had no significant effect on the selenium content of pasture. However, management practices such as high stocking rates and rates of application of superphosphate to pasture were associated with low blood glutathione peroxidase activities in sheep. It was concluded that the selenium nutrition of most of the sheep flocks in Victoria is adequate, and that the deficient areas are localised. There seems little requirement for supplementation of adult sheep. As the delayed type of white muscle disease in spring lambs appears to be the main selenium-responsive disorder, direct supplementation of lambs in the low selenium areas would be the most effective method of ensuring adequate selenium nutrition.


Assuntos
Selênio/sangue , Ovinos/sangue , Animais , Austrália , Geografia , Glutationa Peroxidase/sangue , Estações do Ano
19.
Anim Behav ; 86(4): 733-740, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24109148

RESUMO

Aposematic prey warn predators of their toxicity using conspicuous signals. However, predators regularly include aposematic prey in their diets, particularly when they are in a poor energetic state and in need of nutrients. We investigated whether or not an environmental factor, ambient temperature, could change the energetic state of predators and lead to an increased intake of prey that they know to contain toxins. We found that European starlings, Sturnus vulgaris, increased their consumption of mealworm, Tenebrio molitor, prey containing quinine (a mild toxin) when the ambient temperature was reduced below their thermoneutral zone from 20 °C to 6 °C. The birds differed in their sensitivity to changes in ambient temperature, with heavier birds increasing the number of toxic prey they ate more rapidly with decreasing temperature compared to birds with lower body mass. This could have been the result of their requiring more nutrients at lower temperatures or being better able to detoxify quinine. Taken together, our results suggest that conspicuous coloration may be more costly at lower temperatures, and that aposematic prey may need to invest more in chemical defences as temperatures decline. Our study also provides novel insights into what factors affect birds' decisions to eat toxic prey, and demonstrates that selection pressures acting on prey defences can vary with changing temperature across days, seasons, climes, and potentially in response to climate change.

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