Dark Ones Research Articles

The Three Hundred: The existence of massive dark matter-deficient satellite galaxies in cosmological simulations

The observation of a massive galaxy with an extremely low dark matter content (i.e. NGC 1277) has posed questions about how such objects form and evolve in a hierarchical universe. We here report on the finding of several massive, dark matter-deficient galaxies in a set of 324 galaxy clusters theoretically modelled by means of full-physics hydrodynamical simulations. We first focus on two example galaxies selected amongst the most massive and dark matter-deficient ones. By tracing the evolution of these galaxies, we find that their lack of dark matter is a result of multiple pericentre passages. While orbiting their host halo, tidal interactions gradually strip away dark matter while preserving the stellar component. A statistical analysis of all massive satellite galaxies in the simulated clusters shows that the stellar-to-total mass ratio today is strongly influenced by the number of orbits and the distance at pericentres. Galaxies with more orbits and closer pericentres are more dark matter-deficient. Additionally, we find that massive, dark matter-deficient galaxies at the present day are either the remnants of very massive galaxies at infall or former central galaxies of infalling groups. We conclude that such massive yet dark matter-deficient galaxies exist and are natural by-products of typical cluster galaxy evolution, with no specific requirement for an exotic formation scenario.

Physiological characteristics of ornamental caladiums (Caladium x hortulanum Birdsey, Araceae Juss.) through leaf colour diversity

This work aims to analyze the physiological characteristics of caladium ornamental plants with different leaf colors. Ten leaf colors, i.e., dark maroon, maroon, red, pink, white, pinkish young green, yellow, lime green, pinkish dark green, and dark green, were arranged in a completely randomized design and subjected to colorimetric red–green–blue (RGB) and portable photosynthesis measurement. Caladium leaf color, defined by the colorimetric RGB value, significantly impacted leaf physiological properties. Heatmap analysis apparently clustered caladiums into dark-colored group and light-colored ones. Dark-colored caladiums, as indicated by lower RGB values, exhibited higher photosynthesis rate, stomatal conductance, and water use efficiency (WUE). In contrast, light-colored caladium show a higher RGB, leaf temperature and light use efficiency (LUE) than the dark ones. By considering their leaf color-based physiological adaptability, this work recommends moderate sunlight and adequate water conditions for growing light-colored caladiums, while dark caladiums potentially tolerate excess light and water scarcity. Further research, including quantitative pigment analysis, is necessary to verify this hypothesis.

Some novel different solutions for Boussinesq-type models including bright, singular, and dark soliton ones

Some new different kinds of one-soliton solutions for various forms of Boussinesq-type equations are presented in thispaper to describe the nonlinear wave phenomena in coastal and ocean areas such as tsunami waves. These one-solitonsolutions include bright, dark, and singular ones. The property of each solution in coastal and ocean engineering isexplained.

Analyzing optical soliton propagation in perturbed nonlinear Schrödinger equation: A multi-technique study

In this study, the extended hyperbolic function method and unified solver method are applied to examine the propagation of optical solitons in perturbed nonlinear Schrodinger equation. The proposed techniques are characterized as simpler, more concise, and straightforward. They allow for the extension of the class of solutions and the retrieval of a diverse range of optical solitons, including singular, periodic singular, bright, and dark ones. This highlights the significance of the results. The authors emphasize the novelty of these techniques, as they have not been previously applied to recover optical solitons in this model These out comes may be beneficial for further understanding of numerous phenomena that arises in various physical systems and can be castoff for the optical communication resolution. The existence measures for these solutions are also unveiled in the form of constraint parameters. In addition, the pictorial representations of certain solutions depicted in figures undoubtedly play a key role in understanding the behavior and apprehending some of the physical features of the the discovery of a plethora of novel soliton solutions and their accompanying behaviors.

Deficits in Micronutrients and Immunological Response: Editorial Note

When we consider improved nourishment for our bodies, do we remember to priorities our brain? It is the one area of our bodies that has been overused recently. However, we rarely give it special nutritional care. What nutrients does the brain require, and which foods contain them? Eat largely plant-based foods like fruits, vegetables, legumes, and whole grains. Vegetables, particularly green leafy ones like kale and indigenous leaves, dark green ones like broccoli, yellow ones like pumpkin, and purple ones like red cabbage, are high in beneficial vitamins and antioxidants. These are excellent for brain function. Berries, particularly blueberries and other dark red berries prevalent in your local food chain, curcumin found in turmeric, and most nuts, particularly almonds, are beneficial, as is the oil they contain. There is an increased interest in what people eat, and there is just too much information and marketing out there, which can confuse consumers. Foods like chia seeds, pumpkin seeds, and quinoa have recently been labelled as exotic and uniquely beneficial; edible mushrooms are said to be great; and insects, which have always been eaten in Africa, are gaining popularity worldwide.

Anatomical characteristics and resprouting capacity of the underground organs of Bohemian knotweed (Polygonum ×bohemicum)

AbstractThe hybrid Bohemian knotweed [Polygonum ×bohemicum (J. Chrtek & Chrtková) Zika & Jacobson [cuspidatum × sachalinense]; syn.: Reynoutria ×bohemica Chrtek & Chrtková] is part of the worldwide problematic rhizomatous invasive plants that impact (semi-)natural and agricultural systems. In this context, precise knowledge about the morpho-anatomy and resprouting capacity of the underground organs is key information for developing efficient eradication measures. In the present study, we aimed at (1) clarifying existing differences in the morpho-anatomical characteristics of rhizomes and roots, (2) developing an easy-to-apply field identification method for the underground organs, and (3) identifying the main morpho-anatomical features enhancing the rhizomes’ resprouting ability. For this purpose, we collected the underground organs of two wild populations of P. ×bohemicum in Canton Ticino (southern Switzerland) and analyzed the morpho-anatomical differences between rhizomes and roots, using high-resolution microscope images and microtome sections. Collected material was then used for a resprouting capacity test after assessing rhizome characteristics such as weight, total diameter, pith diameter, pith brightness, and pith color. In contrast to roots, rhizomes are characterized by pith tissue in the center and display nodes with peripheral dormant buds that enable them to resprout. Resprouting ability of rhizomes was high (87.1% on average) and depended on the ontogenetic developmental stage of the organs (peak values of 97% for young and clearer-colored organs, 50% for old and dark ones). In conclusion, the smooth pith tissue of rhizomes represents a key discriminating feature between rhizomes and roots, whereas relating existing nodes to the corresponding rhizome pith color allows assessment of the resprouting potential of a knotweed population.

Characterization of Argentine honeys based on odour, colour and flavour attributes by descriprive sensory analysis

Argentina is one of the world’s largest producers of honey. It shows great botanical and geographical diversity that allows producing honey with varied sensory characteristics. Honey samples belonging to Buenos Aires, Catamarca and Misiones provinces (Argentina) were analyzed and typified by their odour, colour and flavour. Sensory attributes depend and phytogeographic origin. No differences were found in sensory analysis beneath years for each province, however significant differences in colour were found between provinces, indicating a distinctive floral composition throughout space. Lighter honeys are produced in Buenos Aires; whereas Misiones and Catamarca produce darker ones. Even though half of Catamarca territory is used for honey production, it yield a wide diversity of honey characteristics related to different ecoregions and several microclimates, making honeys produced indistinguishable from those of the other two provinces studied. A Protected Designation of Origin (PDO) of a broader area for Catamarca province, as Catamarca and Yungas region will solve this problem. Sensory analysis allows making distinctions between phytogeographic regions, fundamentally due to their different flora. A certified PDO will provide honeys with an added value and allow them to access new markets with higher commercial value than standard quality ones.

Investigation of herbal dyes from Symplocos racemosa (Lodh) leaves and optimization of procedure for dyeing using synthetic mordants

The present study deals with the soaked and woven wool fabrics that were dyed with natural dyes extracted from the leaves of Symplocos racemosa (Lodh). The optimization was carried out with different conditions like concentration of dye material, time for extraction of dye, dyeing time and concentration of mordants. Out of the three methods of mordanting, the best shades for lodh leaf dye were obtained using post-mordanting with ferrous sulphate and stannous chloride and simultaneous mordanting with copper sulphate and potassium dichromate. Poor results were observed in the case of pre-mordanting. The colour fastness analysis indicated the light-coloured samples were affected more rapidly as compared to the dark ones. In this study, the lodh leaf dyed samples exhibited fairly good to excellent fastness to light in the case of ferrous sulphate and stannous chloride while good to good in both copper sulphate and potassium dichromate respectively and the results of washing fastness analysis revealed that lodh leaf dyed samples had good to excellent fastness to washing.

Effects of Drought Stress on Seed Germination and Seedling Growth of Alfalfa with Different Seed Coat Colors

Background: Because of the close relationship between seed coat color and forage seed quality, it is of great significance to reveal the effect of seed coat color on seed germination and seedling growth under drought stress. Methods: We explore the effect of different seed coat colors (yellow, dark brown) on the seed germination and seedling growth of alfalfa under simulated drought stress (polyethylene glycol (PEG-6000) with eight osmotic potentials: 0 MPa, -0.1 MPa, -0.2 MPa, -0.3 MPa, -0.4 MPa, -0.6 MPa, -0.8 MPa, -1.0 MPa). Result: Under control conditions, the germination rate and germination energy of yellow seeds (91.6% and 91.2%, respectively) were higher than dark brown seeds (46.2% and 42.0%). The maximum seed germination rate and germination energy were observed in the -0.1MPa treatment for both yellow and dark brown seeds and were higher than control by 1.53% and 0.66% (yellow) and 9.96%, 14.76% (dark brown), respectively. The root length and seedling growth of two kinds of seeds were significantly inhibited when drought intensity increased. In summary, the germination and seedling growth traits of yellow seeds were much better than dark brown ones. Agronomically, selecting seed with high proportions of yellow coat color is more beneficial for seed storage and establishment of new alfalfa grasslands.

Analysis of new soliton type solutions to generalized extended (2 + 1)-dimensional Kadomtsev-Petviashvili equation via two techniques

In this paper, we examine the solitary wave solutions of the generalised (2 + 1) extended Kadomtsev–Petviashvili (eKP) equation, which is used as model for the surface waves and internal waves in straits or channels and describes the dynamics of nonlinear waves in plasma physics and fluid dynamics. We secure distinct soliton solutions by employing two amelioration methodologies, namely the improved F-expansion method and the new Kudryashov method. These methods explore several unique forms of solitary wave solutions, including dark, rational, singular, periodic, and exponential ones. In order to illustrate propagation of some reported wave solutions, the graphs associated with these solutions are presented by choosing appropriate parametric values in 2D, 3D, contour, and density plots with the use of the symbolic software Mathematica 13.0. The presented solutions realize very significant fact for investigation the qualitative interpretations for various phenomena in our nature. The computed solutions revealed that the applied methods are influential, efficious and skilful and can be a best way to handle other higher order nonlinear evolution equations.

Different Trap Types Depict Dissimilar Spatio-Temporal Distribution of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in Cotton Fields

Pheromone-baited traps have been widely used for the monitoring of the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), in order to time any control measures during the growing season. Different monitoring techniques may provide differential results regarding adult captures. However, studies on the comparative evaluation of the performance of different trap types on the captures of H. armigera are limited. To close this gap, in the present study, three different funnel traps (striped, green, and colored) were simultaneously evaluated in Central Greece, one of the main cotton-producing geographical zones in the European Union, in order to compare trap performance on the captures of H. armigera, as well as to depict the distribution of this species per trap in the study area. A differential performance of the different trap types tested, expressed as numbers of adults captured, was recorded. Specifically, the striped trap captured many more adult moths than the other two trap types. Given that the only difference among these traps was the color of the external trap surface, we hypothesize that trap color does matter in the case of H. armigera, and it is likely that brighter colors may be more attractive than darker ones.

Color discrimination threshold of human vision for textiles under different illumination conditions

In this work, the varying color discrimination thresholds of human vision for textiles with a wide range of physical color attributes under different illumination conditions were examined. It was found that, regardless of the illumination condition and the color attributes of the textiles, people cannot generally perceive the color differences of textiles smaller than 4.25 Δ E*ab. Meanwhile, the color discrimination threshold was found to be significantly affected by the illuminance of illuminants and all the physical color attributes of lightness, chroma, and hue of the textiles observed. People were generally better able to distinguish color differences in bright environments with the illuminance of 2000 lux than in darker ones with 100 lux. In addition, color differences between dark and less-saturated textiles were found to be generally easier to be perceived than those between light and saturated textiles under various illuminants. In addition, regardless of the illuminant, color differences between neutral colored textiles were easier to be perceived than those between chromatic colored textiles with the mean color discrimination threshold of 2.85 and 4.42 Δ E*ab, respectively. In particular, among chromatic colored textiles, color differences between yellow textiles were generally the hardest to be perceived with the mean threshold of 5.58 Δ E*ab.

A Computationally Efficient Red-Lesion Extraction Method for Retinal Fundus Images

Retina is an important organ of the body, the diseases of which may lead to serious damages to human vision. Fundus retinal images are the common tools for the analysis of diabetic retinopathy (DR), which is an important retinal disease. Red-lesions are from important manifestations of DR in the fundus images. In this article, a novel method is suggested for the extraction of red-lesions from fundus images. This method can detect red-lesions without the need for prior segmentation of blood vessels or lesions. The new method works based on dividing the fundus image into square patches and finding the dark ones based on the percentage of dark pixels. After finding dark patches, it is necessary to discriminate the patches that belong to the blood vessel and red-lesion. The continuing structure of blood vessels is considered a discriminating factor for the mentioned purpose. To mathematically model the continuing structure, several states are considered for the way of locating dark patches in a neighborhood. The formation of the blood vessel in vertical, horizontal, and diagonal directions is modeled in the different states. Also, the conditions of the formation of red-lesion in each direction are declared. The performance of the proposed method is evaluated on several datasets. The simplicity of computations, high speed, and acceptable accuracy are significant advantages of this method. The proposed method is capable of providing 92% and 88% for sensitivity (SE) and specificity (SP) in the Diaretdb1 dataset. Also, it provides the values of 91% and 89% for SE and SP in the Diaretdb0 dataset. Furthermore, the SE and SP values for the FIRE dataset are equal to 90% and 92%, respectively.

The effect of three body positions on colour preference: An exploration of microgravity and lunar gravity simulations

Understanding the colour preference in microgravity environments will enable better design of future spacecraft and extra-terrestrial environments. In this study, a space station's crew cabin was simulated and evaluated in 33 different colours by 55 participants using a standard body position change methodology in controlled conditions. Three body positions were tested, and included normal sitting position (SP), to reflect terrestrial conditions; −15° head-down (HD) bed rest, to simulate a microgravity state; and 9.6° head-up tilt (HU) bed rest, to simulate a lunar gravity state. VR devices were worn by participants to ensure an immersive environment in which to evaluate the different coloured environments across the three different body positions. The results show that in all colour environments, there was no significant difference in the colour preference between SP and HU, but there was a significant change in the colour preference in HD compared to SP and HU. In the three positions, the participants appeared to prefer lighter colours rather than darker ones, warmer colours in ST and HU, and cool colours in HD. In this short-term simulation study, no evidence of gender differences in colour preference by body position was found, but in each body position, men and women had different preference levels for basic hue and chroma brightness.

How accurate is transcutaneous bilirubin testing in newborns with darker skin tones?

Fairly accurate. Photometric transcutaneous bilirubin (TcB) testing may overestimate total serum bilirubin (TSB) in neonates with darker skin tones by a mean of 0.68 to > 2 mg/dL (strength of recommendation [SOR]: C, diagnostic cohort studies with differing reference standards).Overall, TcB meters retain accept able accuracy in infants of all skin tones across a range of bilirubin levels, despite being more likely to underestimate lighter skin tones and overestimate darker ones (SOR: C, diagnostic cohort studies with differing reference standards). It is unclear if the higher readings prompt an increase in blood draws or otherwise alter care.

Extraction and Dyeing of Environmental friendly Natural dye from Tung leaves on wool fabrics and optimization of procedure for dyeing using Metallic mordants

The current study deals with the soaked wool fabrics dyed with natural dyes extracted from the leaves of Rhus parviflora. The optimization was carried out for the different variables: concentration of dye material, time for extraction of dye, dyeing time, concentration of mordants and methods of mordanting. Out of the three methods of mordanting, the best shades for dye were obtained using pre-mordanting with ferrous sulphate and potassium dichromate and post-mordanting with copper sulphate and stannous chloride. The colour fastness tests indicated that all samples change in colour on exposure to light. The light coloured samples were affected more rapidly as compared to the dark ones. The Tung leaf dyed samples exhibited fairly good to good fastness to light and the results of washing fastness tests showed that dyed samples had good to excellent fastness to washing.

A comprehensive study of complex non-adiabatic exciton dynamics in MoSi2N4

Excitons, which are composite boson quasi-particles composed of bound electrons and holes, have many fascinating properties and great potential in practical applications. Though experimental studies on exciton dynamics are well-developed, the ab initio simulation ones still remain vacant until two years ago. Here, we apply the density functional theory (DFT) and many-body perturbation theory (MBPT) on 2D MoSi2N4 to study its exciton-related physics and non-adiabatic ultrafast exciton dynamics theoretically and numerically for the first time. Due to its wide band gap, large exciton binding energy and similar 2D hexagonal crystal structure to transition-metal dichalcogenides (TMDs), we expect MoSi2N4 to have distinguished excitonic properties. We calculate the photoluminescence (PL) spectra with final states as bright excitons, yet lots of them are contributed by the dark ones, and the results match the experimental ones perfectly. We also study the dark-exciton-involved processes, which were barely studied in the past but dominate in many physical processes, and obtain several main results like: (i) High scattering rates over the whole Brillouin zone (BZ) within the order of magnitude from 10−2 fs−1 to 101 fs−1; (ii) Thorough analysis for the dynamics of the dark excitons at Λ valley, which have negative effective mass and the highest scattering rate among several exciton states; (iii) Simulate the time-resolved evolution of the excitons after photo-excitation with the real-time Boltzmann transport equation (rt-BTE) techniques, in which process excitons at K/K′ valley play an important role; (iv) Exciton dynamics with spin-valley locking at K/K′ valley are also discussed here; (v) A new approach is proposed for modulating the non-adiabatic effects for excitons, accompanied by a chiral phonon absorption/emission, by tuning the chirality of the external circularly polarized light. All the results show that the 2D material MoSi2N4 is an ideal platform to study the exciton-involved physics and has great application value.

Regulation of soliton inside microresonators with multiphoton absorption and free-carrier effects.

The influence of frequency detuning on the field in silicon microresonators with multiphoton absorption and FC effect is investigated. In this study, results show that frequency detuning facilitates soliton generation. With appropriate frequency detuning, not only bright solitons but also dark ones can be excited in silicon microresonators, which compensates for the absence of solitons with multiphoton absorption and FC. In particular, the larger the frequency detuning is, the wider is the combs spectrum with 2PA obtained. In order to excite the soliton efficiently, the regulation of frequency detuning with multiphoton absorption and FC effect is also studied. In regulating the frequency detuning process with 2PA, a progressively enhanced soliton can be formed in the region near zero detuning. In the tuning process, 3PA can generate bright and dark solitons respectively at various detuning intervals, and independent bright solitons can be observed in microresonators with 4PA. The research results are significant for studying the generation of solitons in silicon microresonators with multiphoton absorption and FC effect.

Antibacterial and Biofilm Degradation Effects of Hungarian Honeys Linked With Botanical Origin, Antioxidant Capacity and Mineral Content.

The aim of the study was to assess the impact of four unifloral honeys on the food-borne pathogens Pseudomonas aeruginosa and Staphylococcus aureus, by analyzing the honeys’ antibacterial and biofilm degradation effects, as well as their antioxidant activity and element content. Linden and milkweed honeys represented light colored honeys, while goldenrod and chestnut honeys the darker ones. The botanical origin of the honeys and the relative frequency of their pollen types were established with melissopalynological analysis. The antioxidant capacities were calculated by two single electron transfer based methods (TRC – Total Reducing Capacity and TEAC – Trolox Equivalent Antioxidant Capacity) and a hydrogen atom transfer based assay (ORAC – Oxygen Radical Absorbance). The amount of four main macro- and two microelements was quantified. The antibacterial activity was determined by minimum inhibitory concentration (MIC) and membrane degradation assays. Furthermore, the biofilm degradation power of the samples was studied as well. The light colored linden honey with the lowest TRC and TEAC, but with the highest ORAC antioxidant activity and high element content showed the best antibacterial and biofilm degradation effects. Meanwhile, the dark colored chestnut honey with significantly higher single electron transfer based antioxidant capacities, with high element content, but lower ORAC showed significantly higher MIC and lower membrane degradation activity than linden honey. In case of biofilm degradation, both honey types gave similarly high inhibitory effect. Goldenrod honey was similarly effective regarding its MIC properties like chestnut honey, but had significantly lower antioxidant potential and ability to disrupt bacterial membranes and biofilms. Milkweed honey was the honey type with the lowest bioactivity and element content. The honeys, unequivocally characterized by their antioxidant characters and element content, displayed different antibacterial and biofilm degradation effects. In addition, some honey traits were found to be good predictors of the antimicrobial potential of honeys: ORAC assay showed correlation with the MIC values of both bacteria, and strict correlation was found between the mineral content and the antibiofilm activity of the studied honeys. Our studies indicate that unifloral honeys, such as linden and chestnut honeys, are plant-derived products with great potential as antimicrobial agents in food preservation, exhibiting remarkable antibacterial activity against food-borne pathogens.

Intraspecific Variability of Melasis buprestoides (Linnaeus, 1761) Challenges the Validity of Melasis fermini Sánchez-Ruiz and Rosa, 2003 (Coleoptera: Eucnemidae)

A study of the variation in morphology and color showed that all characters used for defining Melasis fermini Sánchez-Ruiz and Rosa, 2003 fall within the range of variation found in Melasis buprestoides (Linnaeus, 1761). In addition, small specimens of M. buprestoides with red elytra agreed with large dark ones in their DNA barcodes. As both forms could be reared from the same source wood as well, it is clear that they cannot be regarded as two different species. Consequently, we regard M. fermini to be a junior subjective synonym of M. buprestoides.