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At least 19 recordsLinked to original sources
PubMed2000

[Conclusions of the Canary Islands Nutrition Survey (1997-98). Foundations for a nutrition policy in Canary Islands].

The principal findings of the Canary Island Nutrition survey (ENCA). 1997-98 are presented. This survey was realised to obtain the following objectives: to evaluate eating habits and nutritional status utilising dietary, anthropometric and biochemical indicators in the Canary Island population along with determining lifestyle factors and the prevalence of the main cardiovascular risk factors. Additionally, a survey evaluating food-related knowledge and attitudes was also carried out. To attain this end, a cross-sectional study was realised in a representative sample of the Canary Island population aged 6 to 75 years (n = 1,747). This article summarises the key findings related to study objectives as well as study-derived recommendations to be realised within a Canary Island health and nutrition policy framework. For this purpose, the development of food based dietary guidelines addressed to meet target nutrients is needed.

Adolescent↗
PubMed2000

[Incidence of type 1 diabetes mellitus in the Canary Islands (1995-1996). Epidemiologic Group of the Canary Society of Endocrinology and Nutrition].

OBJECTIVE: To prospectively evaluate the incidence of type 1 diabetes mellitus in patients up to 30 years of age in the Canary Islands during 1995 and 1996. PATIENTS AND METHODS: The population under study consisted of 744,444 inhabitants in the 0-29 year old group and 302,293 in the 0-14 year old group. The capture-recapture method was used for estimating the probability of ascertainment. Hospital records and endocrinologists' reports were the primary source, whereas reports from the Canary Diabetes Association reports and sales of blood glucose monitors were the secondary source. RESULTS: A total of 223 new cases of type 1 diabetes mellitus were detected during the study period. The degree of ascertainment was 90.1%. The observed incidence rates were 23.2 per 100,000 per year for the 0-14 year old group and 9.2 per 100,000 per year for the 15-29 year old group. The overall incidence rate was 15 per 100,000 per year for the entire group. The highest incidence was found in the 10-14 year old group. The incidence in males was higher than in females, and particularly significant in the 15-29 year old group. No seasonal onset pattern was detected. CONCLUSIONS: A high rate of incidence of type 1 diabetes mellitus was observed in this study in children aged less than 15 years living in the Canary Islands.

Adolescent↗
PubMed1982

[A genetic disorder of vitamin A metabolism is recessively white canaries].

A discussion of vitamin A and carotene metabolism in recessively white canaries has been going on for years. This colour canary is reputed to be a 'weak' bird. In the present study, the concentrations of vitamin A, total carotenoid and beta carotene in the serum, liver and feed of both coloured and recessively white canaries were determined. The most important conclusions are: - The normal concentration of vitamin A in the livers of health canaries varies from 500 to 1,500 I.U. of vitamin A per gram of liver. - This is achieved by administering an amount of approximately 15,000 U.U. of vitamin per kg of egg feed. The intake through the feed by each canary will then be approximately 800 I.U. of vitamin A/kg. of body weight daily. - Carotenoids are practically not resorbed from the intestine by recessively white canaries. Vitamin A is also absorbed to a less extent by these birds than it is by canaries which are not recessively white. For their supplies of vitamin A, recessively white canaries are completely dependent on the pressure of vitamin A in the feed. - It would appear to be essential to increase the vitamin A content of the egg feed for recessively white canaries to 20,000 I.U./kg. of egg feed.

Animal Feed↗
PubMed1997

Evidence for supporting cell proliferation and hair cell differentiation in the basilar papilla of adult Belgian Waterslager canaries (Serinus canarius).

We used the bromodeoxyuridine technique to study the proliferative activity in the basilar papilla of normal and Belgian Waterslager canaries with and without preceding sound trauma. Without sound trauma, there were, on average, six supporting cell divisions per day in the basilar papilla of Waterslager canaries. This rate of supporting cell proliferation corresponds well with estimates of the rate of hair cell differentiation derived from counts of immature-appearing hair cells obtained by using scanning electron microscopy of the Waterslager basilar papilla. Thus, supporting cell division appeared correlated with hair cell differentiation in Waterslager canaries. Bromodeoxyuridine labeling of cells in undamaged non-Waterslager canaries also indicated a very low rate of supporting cell division. In contrast with Waterslager canaries, this low rate of proliferation was not associated with a measurable rate of hair cell differentiation. In both normal and Waterslager canaries, exposure to traumatizing sound induced a dramatic increase in the rate of cell proliferation. These data show that a very low rate of supporting cell proliferation is normally present in birds, but it is not associated with a corresponding rate differentiation of hair cells. Only an increase above this low ambient rate of supporting cell proliferation, such as that following loss of hair cells, induces the differentiation of new hair cells in birds. The reason why Waterslager canaries do not completely compensate for their inherited hair cell deficit of 30% is not clear, when they can clearly respond to additional cochlear trauma from noise exposure with an increase in proliferation rate.

Animals↗
PubMed2000

Lesions of the anterior forebrain song control pathway in female canaries affect song perception in an operant task.

We tested whether the avian anterior forebrain pathway functions in song perception in female canaries, and whether it is specialized for conspecific song perception or functions more generally in auditory perception. Using operant conditioning methods, we trained female canaries to discriminate among synthetic sound stimuli, canary songs, and song sparrow songs. We also trained each bird to discriminate among visual stimuli to test for general effects of lesions on performance. When canaries had learned the discrimination tasks, bilateral electrolytic lesions of the lateral portion of the magnocellular nucleus of the anterior neostriatum (lMAN) were made. The lesioned birds were then tested on the previously learned discrimination tasks. Lesions that destroyed most or all of lMAN decreased the ability of female canaries to discriminate between previously learned pairs of acoustic stimuli of all types, while visual discrimination was unaffected. These results suggest that the female canary anterior forebrain pathway contributes to the perception of acoustic stimuli, with this contribution including heterospecific song and other acoustic stimuli as well as canary song.

Acoustic Stimulation↗
PubMed1995

Peripheral basis for the auditory deficit in Belgian Waterslager canaries (Serinus canarius).

Recently, behavioural thresholds obtained in canaries of the Belgian Waterslager strain showed that these birds have an inherited auditory deficit. Canaries of this strain have absolute auditory thresholds at frequencies above 2.0 kHz that are as much as 40 dB above the threshold of canaries of other strains. We obtained audiograms from cochlear microphonics and from compound action potentials from the 8th nerve of Waterslager and non-Waterslager canaries and compare these results to previous behavioural data on hearing in this species. We also examined the growth of evoked potential amplitude-intensity functions in Waterslager and non-Waterslager canaries. Together with reflectance measurements of middle-ear function from both Waterslager and non-Waterslager canaries, we conclude that the origin of auditory deficit in Waterslager canaries lies in the cochlea.

Acoustic Stimulation↗
PubMed2000

Neither endocochlear potential nor tegmentum vasculosum are affected in hearing impaired belgian waterslager canaries.

We previously showed that the Belgian Waterslager canary strain is affected by a hereditary hearing loss that is associated with a reduced number of hair cells and hair cell pathologies in the basilar papilla. Since hair cell pathologies were also present in the sacculus, Weisleder et al. (1994) suggested that these birds are afflicted by Scheibe's like dysplasia, a cochleo-saccular defect. In mammals, cochleo-saccular defects are characterized primarily by the lack of an endocochlear potential and abnormalities in the Stria vascularis which only secondarily lead to hair cell loss (Steel and Bock, 1983; Steel, 1994; 1995). Here we report the endocochlear potential of six ears from three non-Belgian Waterslager canaries and three ears of two Belgian Waterslager canaries to decide if Waterslager canaries are affected by a cochleo-saccular or by a neuroepithelial defect. The mean endocochlear potential was 17.6+/-2. 5 mV in the non-Waterslager canaries and 20.3+/-0.6 mV in Waterslager canaries. In addition, and consistent with the presence of a normal endocochlear potential, light microscopy of the tegmentum vasculosum provided no evidence for pathology. These data show that Belgian Waterslager canaries are affected by a neuroepithelial rather than a cochleo-saccular inner ear defect.

Animals↗
PubMed2000

Nutrition and energetics of the canary (Serinus canarius).

Canaries appear to be primarily seed-eaters, although there are no reports of their feeding ecology in the wild. In captivity, they are offered seed-based diets, preferring to consume seeds such as canary, rapeseed and millet. The mean daily dry-matter intake ranges from 3 to 4 g, which corresponds to a mean gross energy intake of approximately 70 kJ per bird per day. The efficiency of dietary metabolism is high (0.85), which equates to individual metabolizable energy intakes of 45-75 kJ per bird per day. For a canary of average body weight (22 g) the data can be fitted to a regression equation to predict a requirement of 62 kJ ME per day. This corresponds to published information on the energy requirements of other passerine species, but deviates from the predictive equation for poultry. The digestibility values for protein, fat and carbohydrate are similar to those obtained for the budgerigar, although it is likely that the digestibility coefficient is dependent upon the seed type and alimentary tract lipase and amylase activities. Nutrient requirements of canary chicks have not yet been determined, although recent studies have provided data on the nutrient intakes of developing chicks. The newly-hatched canary chick has a rapid growth rate, achieving 90% of its asymptotic body mass by 11 days of age. Gross energy intake is approximately 3 kJ per day following hatching and by day 10 is equivalent to that of an adult canary. It appears that the protein intake should lie between 16.5 and 21.9% of the diet (as is), with peak intake occurring between 8 and 10 days of age.

Animals↗
PubMed2001

A quantitative analysis of the nerve fibers in the VIIIth nerve of Belgian Waterslager canaries with a hereditary sensorineural hearing loss.

The number of auditory nerve fibers was determined for non-Belgian Waterslager canaries (non-BWS) and Belgian Waterslager canaries (BWS) that are affected by a sensorineural high frequency hearing loss and a 30% reduction in the number of auditory hair cells. Counts were obtained from semithin cross sections of the Durcupan-embedded auditory nerve at the level of the internal auditory meatus. In addition, the number of lagenar fibers was determined from cross sections near the apical end of the cochlear duct in order to separate them from the total number of auditory nerve fibers. The mean number of auditory nerve fibers was 6076 in non-BWS and 5363 in BWS canaries, representing a 12% reduction in BWS. This small reduction in the number of auditory nerve fibers, as compared to the larger reduction in hair cell number, might be explained by a predominant loss of abneural hair cells in BWS, since it has been shown for other species that a large proportion of abneural hair cells are devoid of afferent innervation. In addition, we observed that despite the prominent hair cell pathologies documented for BWS canaries, the mean diameter of auditory nerve fibers from non-BWS canaries (2.22+/-0.81 microm) did not differ from those of BWS canaries (2.21+/-0.96 microm).

Animals↗
PubMed2003

Photoperiodic response of the hypothalamo-pituitary-gonad axis in male and female canaries, Serinus canaria.

Although the gonadal photoperiodic response and its influence upon the song control system in canaries have been extensively studied, photoperiodic regulation of the GnRH system has not been investigated. To examine the relationship between photoperiod and the reproductive neuroendocrine system in male and female canaries, three groups of canaries were exposed to chronic short days (8L:16D; Phsens), acute long days (18L:6D; Phstim) and chronic long days (also 18L:6D; Phrefr) to induce the reproductive states of photosensitivity, photostimulation, and photorefractoriness, respectively. Brain sections were processed for GnRH immunocytochemistry. The canaries in this study did not demonstrate consistent or uniform responses to different photoperiodic treatments. In males, gonad size varied with photoperiod; Phstim males had larger gonads than either the Phsens or Phrefr males. In contrast, there was no difference between groups in female gonad size as a result of photoperiodic treatment. Brain GnRH cell number, cell size, and fiber density were similar in all groups. The results suggest that canaries are not as obligatory photoperiodic as previously thought (or at least not all varieties of domestic canaries are). This could be a result of many years of domestication, the natural history of the species, phylogenetic constraint, or a combination of these factors.

Animals↗
PubMed1993

Testosterone-induced changes in adult canary brain are reversible.

Brain nuclei that control song are larger in male canaries, which sing, than in females, which sing rarely or not at all. Treatment of adult female canaries with testosterone (T) induces song production and causes song-control nuclei to grow, approaching the volumes observed in males. For example, the higher vocal center (HVC) of adult females approximately doubles in size by 1 month following the onset of T treatment. Male HVC projects to a second telencephalic nucleus, RA (the robust nucleus of the archistriatum), which projects in turn to the vocal motor neurons. Whether HVC makes a similar connection in female canaries is not known, although HVC and RA are not functionally connected in female zebra finches, a species in which testosterone does not induce neural or behavioral changes in the adult song system. This experiment investigated whether HVC makes an efferent projection to RA in normal adult female canaries, or if T is necessary to induce the growth of this connection. In addition, we examined whether T-induced changes in adult female canary brain are reversible. Adult female canaries received systemic T implants that were removed after 4 weeks; these birds were killed 4 weeks after T removal (Testosterone-Removal, T-R). Separate groups of control birds received either (a) T implants for 4 weeks which were not removed (Testosterone-Control, T-C) or (b) empty implants (Untreated-Control, O-C). Crystals of the fluorescent tracer DiI were placed in the song-control nucleus HVC in order to anterogradely label both efferent targets of HVC, RA and Area X. Projections from HVC to RA and Area X were present in all treatment groups including untreated controls, and did not appear to differ either qualitatively or quantitatively. Thus, formation of efferent connections from HVC may be prerequisite to hormone-induced expression of song behavior in adult songbirds. The volumes of RA and Area X were measured using the distribution of anterograde label as well as their appearance in Nissl-stained tissue. RA was larger in T-treated control birds than in untreated controls. Experimental birds in which T was given and then removed (T-R) had RA volumes closer in size to untreated controls (O-C). Because the volume of RA in T-treated controls (T-C) was larger than that of birds that did not receive T (O-C), we conclude that the volume of RA increased in both T-C and T-R birds but regressed upon removal of T in T-R birds.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

Testosterone-sensitive vasotocin-immunoreactive cells and fibers in the canary brain.

A sexual difference in vasotocin (VT) immunoreactivity was observed in the canary brain. The male canary displays denser VT innervation of the lateral septum and more VT-immunoreactive cells are visible in the dorsal diencephalon than in the female canary. This sex difference is the consequence of gonadal influences. Castration of male canaries resulted in a substantial decrease of VT immunoreactivity in these septal and diencephalic cells and fibers. Testosterone administration to castrated males restored the original intensity of fiber and cell staining. Testosterone treatment of female canaries induced strong VT immunostaining in the above regions similar to that in the male canary.

Animals↗
PubMed2001

Canary islands-north African population affinities: measures of divergence based on dental morphology.

This investigation addresses two related questions about the origins and biological affinities of the Canary Islands' aboriginal inhabitants. First: With which North African populations do the pre-conquest inhabitants of the Canary Islands have their greatest affinities? Second: Does inter-island biological variability among the Canary Islanders, as has been suggested by other researchers (Hooton 1925, Schwidetzky 1963), imply that potentially different founding populations remained distinct during the pre-conquest period? This study employs dental morphology data derived from pre-conquest skeletons to answer these questions. Non-metric dental traits appear to be controlled by polygenic systems with a low to moderate environmental contribution to the resulting phenotype (Berry 1978, Harris & Bailit 1980, Nichol 1990) and can thus be assumed to reflect genetic relationships. The dental morphology of a sample of Canary Islanders (n = 397) is compared to that of Northwest African samples of Algerian Shawia Berbers (n = 26), Kabyle Berbers (n = 32), Bedouin Arabs (n = 49) and Punic Carthaginians (n = 28) as well as to six samples from Northeast Africa (n = 307) included for the purpose of understanding Canary Islanders' affinities within a wider context. The analysis employs 28 dental traits, quantifying differences in their expression among the various samples through a summary statistic, CAB Smith's Mean Measure of Divergence (MMD). The MMD analysis indicates that the Canary Island sample is most similar to the four samples from Northwest Africa: the Shawia Berbers, Kabyle Berbers, Bedouin Arabs and Carthaginians, less similar to the three Egyptian samples and least like the three Nubian samples. An intra-island comparison among samples from La Gomera, Gran Canaria and Tenerife reveals low, insignificant MMD values in all cases, implying that inter-island dental morphology differences are not so great as to require hypotheses of separate founding populations.

Adult↗