The nocturnal leopard gecko (Eublepharis macularius) uses UVb radiation for vitamin D3 synthesis.

Vitamin D is an important regulator of calcium and phosphorus homeostasis in animals. It can be acquired from the diet or synthesised de novo when skin is exposed to UVb. Vitamin D deficiency can lead to a complex of diseases collectively called metabolic bone disease (MBD). Diurnal lizards without access to UVb are prone to develop vitamin D deficiency, even when dietary vitamin D3 is provided. A trial was conducted to determine whether juvenile nocturnal lizards require access to UVb to prevent vitamin D deficiency. All leopard geckos (Eublepharis macularius) were supplemented with dietary vitamin D3. One group was exposed to low level UVb radiation (33-51 µW/cm2) from hatching until 6 months of age and a second group remained unexposed. Animals were fed ad libitum and their growth and weight gain compared with non-exposed controls. At the end of the trial, blood samples were analysed for vitamin D3 metabolites. The concentration of the vitamin D3 metabolite, 25(OH)D3, was higher in UVb exposed animals (61 ± 20 vs. 38 ± 8 nmol/L), confirming cutaneous synthesis with UVb exposure. Growth and weight gain were similar in both groups, and this, together with the absence of clinical symptoms, suggests that dietary vitamin D3 alone can meet the vitamin D requirements for growth of this nocturnal gecko, during the first six months of life. It remains to be investigated whether the higher vitamin D metabolite levels holds other health benefits for this species, such as improved bone density or immune response.

A comparison of UVb compact lamps in enabling cutaneous vitamin D synthesis in growing bearded dragons.

The effect of exposure to different UVb compact lamps on the vitamin D status of growing bearded dragons (Pogona vitticeps) was studied. Forty-two newly hatched bearded dragons (<24 h old) were allocated to six treatment groups (n = 7 per group). Five groups were exposed to different UVb compact lamps for two hours per day, with a control group not exposed to UVb radiation. At 120 days of age, blood samples were obtained and concentrations of 25(OH)D3 , Ca, P and uric acid were determined. In addition, plasma 25(OH)D3 concentration was determined in free-living adult bearded dragons to provide a reference level. Only one treatment resulted in elevated levels of 25(OH)D3 compared to the control group (41.0 ± 12.85 vs. 2.0 ± 0.0 nmol/L). All UVb-exposed groups had low 25(OH)D3 plasma levels compared to earlier studies on captive bearded dragons as well as in comparison with the free-living adult bearded dragons (409 ± 56 nmol/L). Spectral analysis indicated that all treatment lamps emitted UVb wavelengths effective for some cutaneous vitamin D synthesis. None of these lamps, under this regime, appeared to have provided a sufficient UVb dose to enable synthesis of plasma 25(OH)D3 levels similar to those of free-living bearded dragons in their native habitat.

Photoreceptor spectral sensitivity of the compound eyes of black soldier fly (Hermetia illucens) informing the design of LED-based illumination to enhance indoor reproduction.

Mating in the black soldier fly (BSF) is a visually mediated behaviour that under natural conditions occurs in full sunlight. Artificial light conditions promoting mating by BSF were designed based on the spectral characteristics of the compound eye retina. Electrophysiological measurements revealed that BSF ommatidia contained UV-, blue- and green-sensitive photoreceptor cells, allowing trichromatic vision. An illumination system for indoor breeding based on UV, blue and green LEDs was designed and its efficiency was compared with illumination by fluorescent tubes which have been successfully used to sustain a BSF colony for five years. Illumination by LEDs and the fluorescent tubes yielded equal numbers of egg clutches, however, the LED illumination resulted in significantly more larvae. The possibilities to optimize the current LED illumination system to better approximate the skylight illuminant and potentially optimize the larval yield are discussed.

The practice of primary care sports medicine in the USA.

OBJECTIVE: To investigate and to characterise the practice patterns, academic rank, and income variables that exist in order to better understand the career of a sports medicine physician in the USA. DESIGN: A cross-sectional survey of family physicians holding a Certificate of Added Qualifications in Sports Medicine through the American Board of Family Medicine as of January 2006. RESULTS: The survey was completed by 325 of 862 physicians (a return rate of 38%). Of all respondents, 212 (65%) reported completing a Primary Care Sports Medicine Fellowship, 276 (85%) were male and 49 (15%) were female, and 300 (92%) reported having a MD, while 25 (8%) had a DO. Clinical duties represented the largest proportion of the physicians' schedules (7.94 half days/week), and the majority of physicians performed routine athletic event coverage. The average salary for all physicians was $166,000 US. Higher-income groups included: men ($172,000 vs $132 000 for women); regions including Central, South East, and South West; full professors; and non-student health or urgent care clinical work. With control for all other variables, four groups demonstrated significantly higher odds of being high income earners (annual gross salary > $200,000 US). These groups included age over 40, male sex, practice owner, and seeing over 10 patients per half day. CONCLUSIONS: Salary can be related to age, gender, number of patients seen, and practice ownership. No statistical difference among salaries was found between MDs and DOs, osteopathic manipulative therapy (OMT) practice, region of the country, or how practices are marketed.

Projections of auditory cortex to the medial geniculate body of the cat.

The corticofugal projection from 12 auditory cortical fields onto the medial geniculate body was investigated in adult cats by using wheat germ agglutinin conjugated to horseradish peroxidase or biotinylated dextran amines. The chief goals were to determine the degree of divergence from single cortical fields, the pattern of convergence from several fields onto a single nucleus, the extent of reciprocal relations between corticothalamic and thalamocortical connections, and to contrast and compare the patterns of auditory corticogeniculate projections with corticofugal input to the inferior colliculus. The main findings were that (1) single areas showed a wide range of divergence, projecting to as few as 5, and to as many as 15, thalamic nuclei; (2) most nuclei received projections from approximately five cortical areas, whereas others were the target of as few as three areas; (3) there was global corticothalamic-thalamocortical reciprocity in every experiment, and there were also significant instances of nonreciprocal projections, with the corticothalamic input often more extensive; (4) the corticothalamic projection was far stronger and more divergent than the corticocollicular projection from the same areas, suggesting that the thalamus and the inferior colliculus receive differential degrees of corticofugal control; (5) cochleotopically organized areas had fewer corticothalamic projections than fields in which tonotopy was not a primary feature; and (6) all corticothalamic projections were topographic, focal, and clustered, indicating that areas with limited cochleotopic organization still have some internal spatial arrangement. The areas with the most divergent corticothalamic projections were polysensory regions in the posterior ectosylvian gyrus. The projection patterns were indistinguishable for the two tracers. These findings suggest that every auditory thalamic nucleus is under some degree of descending control. Many of the projections preserve the relations between cochleotopically organized thalamic and auditory areas, and suggest topographic relations between nontonotopic areas and nuclei. The collective size of the corticothalamic system suggests that both lemniscal and extralemniscal auditory thalamic nuclei receive significant corticofugal input.

Auditory cortical projections to the cat inferior colliculus.

The projection from 11 auditory cortical areas onto the subdivisions of the inferior colliculus was studied in adult cats by using two different anterograde tracers to label cortico-collicular (CC) axon terminals. The main results were that: 1) a significant CC projection arose from every field; 2) the principal inferior collicular targets were the dorsal cortex, lateral nucleus, caudal cortex, and intercollicular tegmentum, with only a sparse projection to the central nucleus; 3) the input was usually bilateral, with the ipsilateral side by far the most heavily labeled, and the contralateral projection was a symmetrical subset of the ipsilateral input; 4) the CC system is both divergent and convergent, with single cortical areas projecting to six or more collicular subdivisions, and each auditory midbrain subdivision receiving a convergent projection from two to ten cortical areas; 5) cortical areas devoid of tonotopic organization have topographic projections to collicular target nuclei; 6) the heaviest CC projection terminated in the caudal half of the inferior colliculus; and finally, 7) the relative strength of the cortico-collicular labeling was far less than that of the corresponding corticothalamic projection in the same experiments. The CC system is strategically placed to influence both descending and ascending pathways arising in the inferior colliculus. Nuclei that participate in the premotor system, like the inferior collicular subdivisions that project to the pons, receive substantial corticofugal input. Both the dorsal (pericentral) and the lateral (external) nuclei of the inferior colliculus project to parts of the medial geniculate body whose closest auditory affiliations are with non-tonotopic cortical regions involved in higher order auditory perception. The cortico-collicular system may link brainstem and colliculo-thalamic circuits to coordinate premotor and perceptual aspects of hearing.