Tribute to R.G. Boutilier: Skin colour and body temperature changes in basking Bokermannohyla alvarengai (Bokermann 1956)

In amphibians solar basking far from water sources is relatively uncommon since the highly permeable amphibian skin does not represent a significant barrier to the accompanying risk of losing water by evaporation. A South American frog, Bokermannohyla alvarengai (Bokermann 1956), however, spends a significant amount of the day exposed to full sun and relatively high temperatures. The means by which this frog copes with potentially high rates of evaporative water loss and high body temperatures are unknown. Thus, in this study, skin colour changes, body surface temperature, and evaporative water loss rates were examined under a mixture of field and laboratory conditions to ascertain whether changes in skin reflectivity play an important role in this animal's thermal and hydric balance. Field data demonstrated a tight correlation between the lightness of skin colour and frog temperature, with lighter frogs being captured possessing higher body temperatures. Laboratory experiments supported this relationship, revealing that frogs kept in the dark or at lower temperatures (20 degrees C) had darker skin colours, whereas frogs kept in the light or higher temperatures (30 degrees C) had skin colours of a lighter hue. Light exhibited a stronger influence on skin colour than temperature alone, suggesting that colour change is triggered by the increase in incident solar energy and in anticipation of changes in body temperature. This conclusion is corroborated by the observation that cold, darkly coloured frogs placed in the sun rapidly became lighter in colour during the initial warming up period (over the first 5 min), after which they warmed up more slowly and underwent a further, albeit slower, lightening of skin colour. Surprisingly, despite its natural disposition to bask in the sun, this species does not possess a 'waterproof' skin, since its rates of evaporative water loss were not dissimilar from many hylid species that live in arboreal or semi-aquatic environments. The natural history of B. alvarengai is largely unknown and, therefore, it is likely that the herein reported colour change and basking behaviour represent a complex interaction between thermoregulation and water balance with other ecologically relevant functions, such as crypsis.

The night and day of dung beetles (Coleoptera, Scarabaeidae) in the Serra do Japi, Brazil: elytra colour related to daily activity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of nitrate and phosphate availabilities on growth, photosynthesis and pigment and protein contents in colour strains of Hypnea musciformis (Wulfen in Jacqu.) J.V. Lamour. (Gigartinales, Rhodophyta)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A square-wave voltammetric method for analysing the colour marker quinizarine in petrol and diesel fuels

This work presents an electroanalytical method based on square-wave voltammetry (SWV) for the determination of quinizarine (QNZ) in a mixture of Britton-Robinson buffer 0.08 mol L-1 with 30% of acetonitrile. The QNZ was oxidized at glassy carbon electrode in and the well-defined peak at +0.45 V vs. Ag/AgCl can be used for its determination as colour marker in fuel samples. All parameters were optimized and analytical curves can be constructed for QNZ concentrations ranging from 2.0 x 10(-6) mol L-1 to 1.4 x 10(-5) mol L-1, using f = 60 Hz and E-sw = 25 mV. The method offers a limit detection of 4.12 x 10(-7) mol L-1 and a standard deviation of 4.5% when six measurements of 1.25 x 10(-5) mol L-1 are compared. The method was successfully applied for determining QNZ in gasoline and diesel oil and the obtained results showed good agreement with those reported previously. (c) 2006 Elsevier Ltd. All rights reserved.

Changes in coral reef communities and an associated reef fish species, Cephalopholis cruentata (Lacepede), after 30 years on Curacao (Netherlands Antilles)

Using the same methodology and identical sites, we repeat a study dating from 1973 and quantify cover of hard coral species, soft corals, sponges, hard substratum and soft substratum, and density of a commercially important reef fish species, the graysby Cephalopholis cruentata, along a depth-gradient of 3-36 m oil the coral reefs of Curacao. The objective was to determine the multi-decade change in benthic coral reef cover and structural complexity, and their effect oil densities of an associated reef fish species. Total hard coral cover decreased on average from 52% in 1973 to 22% in 2003, representing a relative decline of 58%. During this time span, the cover of hard substratum increased considerably (from 11 to 58%), as did that of soft corals (from 0.1 to 2.2%), whereas the cover of sponges showed no significant change. Relative decline of hard coral cover and of reef complexity was greatest in shallow waters (near the coast), which is indicative of a combination of anthropogenic influences from shore and recent storm damage. Cover of main reef builder coral species (Agaricia spp., Siderastrea siderea, Montastrea annularis) decreased more than that of other species, and resulted in a significant decrease in reef complexity. Although density of C. cruentata was highly correlated to cover of Montastrea and Agaricia in 1973, the loss of coral cover did not show any effect on the total density of C. cruentata in 2003. However, C. cruentata showed a clear shift in density distribution from shallow water in 1973 to deep water in 2003. It call be concluded that the reefs of Curacao have degraded considerably in the last three decades, but that this has had no major effect on the population size of one commercially important coral-associated fish species.

Effects of ambient colour on colour preference and growth of juvenile rainbow trout Oncorhynchus mykiss (Walbaum)

Colour preference of individual juvenile rainbow trout Oncorhynchus mykiss was tested at 1 and 12 degrees C, and also at 12 degrees C after a 42 day growth experiment under white, blue, green, yellow or red ambient colour. All experiments were carried out under controlled laboratory conditions and the preference was assessed by the location of the fish in a preference tank with four chambers. Rainbow trout showed a preference for blue and green at 1 degrees C and for green at 12 degrees C. After the growth experiment the fish reared in blue tanks preferred blue and green but green was the most preferred colour for the fish reared in green, yellow and red tanks. Yellow and especially red chambers were avoided, irrespective of the ambient colour during the growth trial. The final mass of fish reared in the red aquaria was significantly smaller than that of the fish in green tanks. In addition, when the data of the preference tests were correlated with the data of the growth experiment using mean values of the four tested colours, a very good linear relationship was observed between the preference (i.e. visit frequency in coloured compartments) and growth rate as well as food intake. When considering the results both from the preference and growth trials it is suggested that green is the best environmental colour for rearing juvenile rainbow trout while rearing in a red environment cannot be recommended. (c) 2008 The Authors Journal compilation (c) 2008 The Fisheries Society of the British Isles.

The correlation between subordinate fish eye colour and received attacks: a negative social feedback mechanism for the reduction of aggression during the formation of dominance hierarchies

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of environmental colour on growth of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), maintained individually or in groups

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A Música Coral dos Primórdios do Século XX aos Primórdios do Século XXI: a Composição para Coros e a Performance do Repertório Moderno/Contemporâne

This paper is a small part of my Doctoral dissertation which is a large study about the practice and sonority in various choral music styles. Focusing on the choral music from the beginning of the 20th century to the present day, and based upon a bibliographical review, this article describes the characteristics of the choral composition and reflects on the performance aspects of the performance of modern and contemporary choral repertoire such as vocal tone color, intonation and non-traditional vocal techniques.

Study on the mutagenicity and antimutagenicity of a natural food colour (annatto) in mouse bone marrow cells

Most manufactured foods contain chemicals added as a deliberate part of the manufacturing process. The aims of the present study were to evaluate the mutagenicity and antimutagenicity of annatto, a natural pigment extracted from the Bixa orellana L. and widely used as a colorant in foods. The micronucleus test was performed in bone marrow cells from Swiss male mice treated with one of the three concentrations of annatto (1330, 5330 and 10,670 ppm), incorporated into the diet. The animals were fed with the diets for 7 days and sacrificed 24 h after the last treatment. For the evaluation of the antimutagenic potential of annatto, at day 7, the animals received an intraperitoneal injection of cyclophosphamide (50 mg/kg body weight). Under the concentrations tested annatto did not present mutagenic or antimutagenic activities on the mice bone marrow cells. However, an increased frequency of micronucleated cells was observed when the highest concentration (10,670 ppm) was administered simultaneously with cyclophosphamide. In conclusion, the data indicate that annatto colour, for the conditions used, is neither mutagenic nor an inhibitor of induced mutations, although it should be used carefully since high doses may increase the effect of a mutagen. © 2003 Elsevier Science Ltd. All rights reserved.

Evaluation of hardness and colour change of soft liners after accelerated ageing.

INTRODUCTION: Soft liners have been developed to offer comfort to denture wearers. However, this comfort is compromised when there is a change in the properties of the material, causing colour change, solubility, absorption and hardening. These characteristics can compromise the longevity of soft liners. AIM: The aim of this in vitro study was to investigate the effect of ageing on both the hardness and colour change of two soft liners following accelerated ageing. METHODS: Two denture liners, one resin based (Trusoft, Bosworth, Illinois, USA) and one silicone based (Ufi Gel P, Voco GMBH, Cuxhaven, Germany), were tested in this study for both hardness (using the Shore A scale) and colour change (using the CIE L*a*b* colour scale), initially and after 1008 hours (6 weeks) of accelerated ageing. Statistical analysis was performed using the unpaired t-test with the Welch correction. RESULTS: These indicated that both materials increased in hardness and underwent colour change after accelerated ageing. The initial hardness of Trusoft was far lower than that of Ufi Gel P (18.2 Shore A units vs 34.8 Shore A units). However, for Trusoft the changes for both hardness (from 18.2 to 52.1 Shore A units) and colour change (16.85 on the CIE L*a*b* colour scale) were greater than those for Ufi Gel P, for which hardness changed from 34.8 to 36.5 Shore A units and the colour change was 5.19 on the CIE L*a*b* colour scale. CONCLUSIONS: Ufi Gel P underwent less hardness and colour change after accelerated ageing than Trusoft. On the other hand, the use of Trusoft may be preferable in cases where initial softness is a major consideration, such as when relining an immediate denture after implant surgery.

Profilometry of semiconductor components by two-colour holography with Bi12TiO20 crystals

We studied the shape measurement of semiconductor components by holography with photorefractive Bi12TiO20 crystal as holographic medium and two diode lasers emitting in the red region as light sources. By properly tuning and aligning the lasers a synthetic wavelength was generated and the resulting holographic image of the studied object appears modulated by cos2-contour fringes which correspond to the intersection of the object surface with planes of constant elevation. The position of such planes as a function of the illuminating beam angle and the tuning of the lasers was studied, as well as the fringe visibility. The fringe evaluation was performed by the four stepping technique for phase mapping and through the branch-cut method for phase unwrapping. A damage in an integrated circuit was analysed as well as the relief of a coin was measured, and a precision up to 10 μm was estimated. © 2009 SPIE.

Effect of thermal cycling and disinfection on colour stability of denture base acrylic resin

Objectives: The purpose of this study was to investigate the effect of thermal cycling and disinfection on the colour change of denture base acrylic resin. Materials and Methods: Four different brands of acrylic resins were evaluated (Onda Cryl, QC 20, Classico and Lucitone). All brands were divided into four groups (n=7) determined according to the disinfection procedure (microwave, Efferdent, 4% chlorhexidine or 1% hypochlorite). The treatments were conducted three times a week for 60days. All specimens were thermal cycled between 5 and 55°C with 30-s dwell times for 1000 cycles before and after disinfection. The specimens' colour was measured with a spectrophotometer using the CIE L*a*b* system. The evaluations were conducted at baseline (B), after first thermal cycling (T 1), after disinfection (D) and after second thermal cycling (T 2). Colour differences (ΔE) were calculated between T 1 and B (T 1B), D and B (DB), and T 2 and B (T 2B) time-points. Results: The samples submitted to disinfection by microwave and Efferdent exhibited the highest values of colour change. There were significant differences on colour change between the time-points, except for the Lucitone acrylic resin. Conclusions: The thermal cycling and disinfection procedures significantly affected the colour stability of the samples. However, all values obtained for the acrylic resins are within acceptable clinical parameters. © 2012 The Gerodontology Society and John Wiley & Sons A/S.

Influence of natural weathering on colour stability of materials used for facial prosthesis

Colour stability of resin and silicone is an important factor for longevity of facial prostheses. The aim of this study was to evaluate the colour stability of resins and silicone for facial prostheses. Three brands of acrylic resin and one of facial silicone were evaluated considering pigment incorporation for the colourless materials. Ten samples of each material were fabricated and submitted to measurements of chromatic alteration initially and after 90 and 180 days of weathering natural through visual analysis and spectrophotometry. Data were evaluated by ANOVA and Tukey test (p < 0.05). Statistically significant colour alteration was observed among some materials regardless of the period. The materials did not present a statistical difference between 90 and 180 days except for the pigmented heat-polymerized resin. The colour difference between pigmented Silastic MDX4-4210 and colourless Silastic was statistically significant (p < 0.01) in both periods as well as between pigmented and colourless heat-polymerized resin, and between the resins Rapidaflex and Lentaflex. The visual method demonstrated colour alteration in all materials evaluated during the first 90 days of ageing. All materials exhibited colour alteration due to exposure to environment. © 2012 Informa UK, Ltd.