scholarly journals Incidence of the thermal transition in the range of 45-5°C in chromatophores present in the wings of Schistocerca americana

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 223
Author(s):  
María Belén Cañizares ◽  
Nathaly Naranjo ◽  
Bence Mátyás

The variation of the color intensity of the chromatophores present in the wings of Schistocerca americana was analyzed by exposing 31 specimens to thermal transitions within the range of 45 - 5 °C.  The adult specimens were collected using a mini-terrarium of dimensions 40x40x30 cm. As a substrate, a layer of soil, stones, and finally a layer of grass were used along with branches of bushes and leaves; hydroponic lettuce, cabbage and the grass were used as food for the specimens. Optical microscopy of the wings of the insects was used for live observation without coverslips or contrasting substances. At 45°C, degradation of color intensity was observed in the chromatophores present in the wings. At 5°C, chromatophores intensify their color to brownish-black. This temperature was the extreme minimum that S. americana could tolerate. We found negative correlation between the temperature and the degree of darkness (R2 = 0.8038). Our results are in accordance with a previously published study in which Phaulacridium vittatum was examined, as the decrease of temperature caused darkening color change in melanin-type chromatophores. The present investigation can be considered as the first initial study of its kind for S. americana, in terms of examining the changes in the color intensity of the chromatophores present in the wings caused by thermal transition under laboratory conditions.

Soft Matter ◽  
2014 ◽  
Vol 10 (34) ◽  
pp. 6467-6476 ◽  
Author(s):  
Choonghyun Sung ◽  
Katelin Hearn ◽  
Jodie Lutkenhaus

Layer-by-layer assemblies exhibit increased conductivity and decreased charge transfer resistance upon heating through the thermal transition.


Author(s):  
I. M. Jurinskaya ◽  
S. M. Rakhimova ◽  
T. E. Kenzhebaeva ◽  
B. ZH. Niyazbekov ◽  
K. A. Iskakov

The article is devoted to the study and assessment of the technological properties of down based on the technology of dyeing down from goat wool from various genotypes of goats of the republic. The dyeing was carried out under laboratory conditions with Italian dyes. The dependence of the color intensity for downy fibers is described by polynomial equations of the second and third degree. It has been shown that goat down fibers have good dyeing ability, dyeing uniformity and show good dyeing performance in standard modes.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Marcos Flores ◽  
Jaime Ortiz-Viedma ◽  
Ayelen Curaqueo ◽  
Alicia Rodriguez ◽  
Gretel Dovale-Rosabal ◽  
...  

In Chile, the most cultivated avocado varieties are Hass and Negra de la Cruz. The increase in the production of fast food preparations, salads, and avocado oil has generated large amounts of seeds and husks as waste, which may constitute a possible new source of bioactive compounds, of great interest to the food and pharmaceutical industry. Therefore, the objective of this study was to determine different nutritional, biochemical, antimicrobial, and physical properties of the SH and SNC seeds grown in Chile. In SH and SNC, their nutritional composition, lipophilic components, and total phenols (PTs) were determined. The antioxidant and antibacterial activity of extracts were measured in different solvent combinations. In addition, the color change of seeds (ΔE) during the browning, the mechanical resistance to the cut, and their thermal transitions by differential calorimetry (DSC) were determined. The results indicated that SH has a higher protein content and lipophilic components. In the ethanol extract, SNC showed greater antiradical activity and is an inhibitor of Gram (+) bacteria. The SNC browning given by ΔE was greater and adjusted well to kinetic and enzymatic models. The physical analyses of the seeds indicated that SNC presented higher cut resistance and lower transition temperature (Tg) with a lower thermal fusion of its lipids, which would be due to its higher unsaturated composition. These properties of SH and SNC can be useful for the agrifood, pharmaceutical, and chemical industries.


Soft Matter ◽  
2014 ◽  
Vol 10 (40) ◽  
pp. 8107-8115 ◽  
Author(s):  
Joseph T. Puhr ◽  
Benjamin E. Swerdlow ◽  
Dariya K. Reid ◽  
Jodie L. Lutkenhaus

When nanoparticles are inserted at different locations within a layer-by-layer (LbL) assembly, a second higher temperature thermal transition appears under select conditions.


2019 ◽  
Vol 25 (1) ◽  
pp. 47-57 ◽  
Author(s):  
Hiroko Kudo ◽  
Kento Maejima ◽  
Yuki Hiruta ◽  
Daniel Citterio

Lactoferrin is an abundant glycoprotein in human body fluids and is known as a biomarker for various diseases. Therefore, point-of-care testing (POCT) for lactoferrin is of interest. Microfluidic paper-based analytical devices (µPADs) have gained a lot of attention as next-generation POCT device candidates, due to their inexpensiveness, operational simplicity, and being safely disposable. This work presents a colorimetric sensing approach for quantitative lactoferrin analysis. The detection mechanism takes advantage of the high affinity of lactoferrin to ferric ions (Fe3+). Lactoferrin is able to displace an indicator from a colorimetric 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP)-Fe3+ complex, resulting in a color change. A 5-Br-PADAP-Fe3+ complex was encapsulated into water-dispersible poly(styrene- block-vinylpyrrolidone) particles, whose physical entrapment in the cellulosic fiber network results in the immobilization of the complex to the paper matrix. The complex-encapsulating particles showed a color change response in accordance with lactoferrin concentration. Both color intensity-based paper well plates and distance readout-based µPADs are demonstrated. Color intensity-based devices allowed quantitative analysis of lactoferrin concentrations with a limit of detection of 110 µg/mL, using a smartphone and a color readout app. On the other hand, distance readout-based µPADs showed changes of the length of colored sections in accordance with lactoferrin concentration. In summary, we successfully developed both colorimetric intensity-based paper wells and distance-based µPADs for lactoferrin detection. This work demonstrates a user-friendly colorimetric analysis platform for lactoferrin without requiring lab equipment and expensive antibodies.


Chemosensors ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 286
Author(s):  
Tatiana G. Choleva ◽  
Christina Matiaki ◽  
Afroditi Sfakianaki ◽  
Athanasios G. Vlessidis ◽  
Dimosthenis L. Giokas

A new method for the determination of chloride anions in sweat is described. The novelty of the method relies on the different photochemical response of silver ions and silver chloride crystals when exposed to UV light. Silver ions undergo an intense colorimetric transition from colorless to dark grey-brown due to the formation of nanosized Ag while AgCl exhibits a less intense color change from white to slightly grey. The analytical signal is obtained as mean grey value of color intensity on the paper surface and is expressed as the absolute difference between the signal of the blank (i.e., in absence of chloride) and the sample (i.e., in the presence of chloride). The method is simple to perform (addition of sample, incubation in the absence of light, irradiation, and offline measurement in a flatbed scanner), does not require any special signal processing steps (the color intensity is directly measured from a constant window on the paper surface without any imager processing) and is performed with minimum sample volume (2 μL). The method operates within a large chloride concentration range (10–140 mM) with good detection limits (2.7 mM chloride), satisfactory recoveries (95.2–108.7%), and reproducibility (<9%). Based on these data the method could serve as a potential tool for the diagnosis of cystic fibrosis through the determination of chloride in human sweat.


1989 ◽  
Vol 67 (4) ◽  
pp. 812-818 ◽  
Author(s):  
Lawrence E. Licht ◽  
James P. Bogart

On Pelee Island, Ontario, mole salamanders, Ambystoma laterale and Ambystoma texanum, coexist with their diploid, triploid, and tetraploid hybrids. In an initial study, A. laterale and hybrid larvae were raised in groups, but from metamorphosis to 5 months postmetamorphosis, individuals were raised in isolation. In a second study, A. texanum and hybrids were raised as isolated individuals under uniform feeding and laboratory conditions from the egg stage to 22 months postmetamorphosis. The total length of larvae at 14 days posthatching was correlated with size of eggs. Tetraploids originated from larger eggs, were larger at 2 weeks posthatching, and maintained their larger size throughout larval development. Tetraploids metamorphosed later and were heavier than all other genotypes. The heavier mass at metamorphosis was maintained and relatively increased so that by 22 months postmetamorphosis, when compared with other groups, tetraploids were heavier in mass, but not larger in snout–vent length. Bodies of tetraploids were more robust and tails, although not longer, were thicker. In contrast to A. texanum and diploid and triploid hybrids, among which 50% of individuals developed fully pigmented, yolk-filled ova by 22 months, no tetraploids showed such signs of sexual maturity. The growth and reproductive patterns of diploids and polyploids are discussed.


2010 ◽  
Vol 1270 ◽  
Author(s):  
David Redinger ◽  
Robert S. Clough ◽  
James C. Novack ◽  
Gregg Caldwell ◽  
Marcia M. Payne ◽  
...  

AbstractModifications to the p-type semiconductor TIPS-Pentacene can result in elimination of the solid-solid thermal transition at 124 °C. This new material has shown mobility higher than 1 cm2/Vs. Elimination of the solid-solid thermal transition leaves the melting point as the lowest temperature transition at 199 °C.


2021 ◽  
Vol 890 (1) ◽  
pp. 012025
Author(s):  
M A Fabanjo ◽  
N Abdullah

Abstract Betta fish is one of the ornamental fish that has high economic value because it has features such as the beauty of the body color, the uniqueness of the shape of the fins so that it is very attractive to ornamental fish lovers. Attractiveness value of ornamental fish can be measured from their brilliant color, shape and physical completeness, behavior, and health conditions. Color is one deciding factor that ornamental fish is in demand by consumers, so that farmers need to maintain the color of ornamental fish by providing food containing color pigments. The aim of this study was to obtain a mixture of effective doses of pro-enzyme Spirulina flour in feeding to increase growth and color intensity of betta fish. The results showed that the highest absolute weight growth was found in treatment B (5 grams) of pro-enzyme Spirulina flour 2.154 followed by treatment C 1.554 (7 grams), treatment A 0.844 (3 grams), and treatment D 0.002 (0 grams). The highest level of color change occurred in treatment A (dose of 3 grams) while the lowest color change rate was found at treatment D (0 grams).


2014 ◽  
Vol 74 (2) ◽  
pp. 438-443 ◽  
Author(s):  
MSCS. Lima ◽  
J. Pederassi ◽  
CAS. Souza

Life tables and survival curves of tadpoles from Rhinella icterica species were studied in the laboratory, under abiotic conditions controlled by a purification filter, a timer and a chiller. The survival curve for larval stage confirms a great mortality trend in the initial stages, which decreases when reaching the mature morphological condition (r = –0.94). Stages 37, 38, 39, 40 and 41 showed gradual values for their age structures, while stages 42, 43 and 44 presented high variations. Based on the results under laboratory conditions, it can be concluded that the maturity of R. icterica tadpoles development between 37 and 44 stages has a negative correlation and their predicted life expectancy is a logarithmic growth curve (y=–761.96Ln(x)+5298.5).


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