Dark Patches Research Articles

Active Boulder Falls in Terra Sirenum, Mars: Constraints on Timing and Causes

AbstractWe use time series images to identify significant active boulder falls in an impact crater on Mars. Evidence for active boulder falls include boulder trails with impact marks from bouncing and rolling, and dark patches from boulder impacts away from the base of the crater walls. We were able to define three time periods with active boulder falls and additional slope streak formation, for which we refined the most significant activity to a time period between January 2012 and March 2013. A search of 236 images within 500 km of the study site identified two further sites with similar, but reduced, activity during the same time period. We discuss plausible mechanisms for the boulder fall activity, and conclude that the local geology and crater age is likely to be of significant importance. Our method of identifying and highlighting such activity will allow further studies of active surface processes on Mars.

Mission to Venus Could Help Solve an Atmospheric Mystery

NASA’s recently announced DAVINCI+ mission to Venus will probe the planet’s atmosphere, hoping to shed light on the unknown dark patches that surround the planet.

A New Cryptic Species of Polymixia (Teleostei, Acanthomorpha, Polymixiiformes, Polymixiidae) Revealed by Molecules and Morphology

A new and previously cryptic fish species, Polymixia hollisterae, new species, proposed common name “Bermuda Beardfish,” is described from two voucher specimens collected in 1997 at a depth of about 280 fm or 512 m on the NW slope of the Bermuda Platform, and a third voucher collected by a midwater trawl in the north-central Gulf of Mexico. The species belongs to the paracanthopterygian acanthomorph genus Polymixia, family Polymixiidae, order Polymixiiformes, and is named after pioneering ichthyologist, ocean explorer, and conservationist Gloria E. Hollister (Anable). It is distinguished from all other species in the genus by its greater dorsal and anal fin heights (19% and 14% of SL, respectively), its extremely long pectoral and pelvic fins (22% and 14% of SL, respectively), its relatively large eye diameter (34% of total head length), and its morphologically distinctive first anal-fin radial. It has a unique pigmentation pattern on the dorsal, anal, and caudal fins consisting of narrow, dark black patches near the tips of the longest few soft dorsal- and anal-fin rays, and a caudal-fin margin with a dark black fringe covering the distal fourth of the fin. Based on an earlier molecular study that revealed it to be a cryptic species, P. hollisterae, new species, is closely related to P. japonica, but it differs by 20–33 nucleotides in a total alignment of 4,983 nuclear and mitochondrial sites. The new species shares a distinctive scale morphology with P. japonica and P. nobilis (the type species); an intermediate number of dorsal-fin rays (V,31–32), like P. japonica (V,31–34); a distinctive preopercle shape with P. japonica, P. lowei, and P. berndti; and a low number of pyloric caeca with P. lowei and P. berndti. Pored lateral-line scales number 35, an intermediate number compared to reported counts of other species (31–39). The three supraneurals are sigmoid-shaped like those of P. nobilis, while dorsal-fin proximal radials interfinger with neural spines in a unique pattern. Body shape, as studied with measurement proportions and multivariate morphometrics, is distinguished by a relatively large head, large eyes, long jaws, and a more streamlined pre-dorsal body profile than its congeners. Further research and additional collecting will be needed to ascertain the geographic distribution and conservation status of the new species.

Taxonomic study of the genus Promalactis Meyrick, 1908 (Lepidoptera: Oecophoridae) XI. The rubra species-group and the fuscimacularis species-group, with descriptions of six new species.

The rubra and the fuscimacularis species-groups of the genus Promalactis Meyrick, 1908 are proposed for the first time based on the forewing patterns. Moths of the rubra species-group are characterized by the ochreous forewing of all shades with a short dorsal spot or a short obliquely inward dorsal streak; moths of the fuscimacularis species-group are characterized by the forewing having a dark basal spot or a dark basal costal patch. Six species are described as new: P. albimarginalis Wang, sp. nov., P. introextensa Wang, sp. nov., P. magnisticta Wang, sp. nov., P. anteromacularis Wang, sp. nov., P. fuscimacularis Wang, sp. nov., P. folivalvaris Wang, sp. nov. Photographs of adults and genitalia of the new species are provided. A list of species belonging to both species-groups is given.

Malar stripe size and prominence in peregrine falcons vary positively with solar radiation: support for the solar glare hypothesis

Many falcons (Falco spp.) exhibit a distinct dark plumage patch below the eye, termed the malar stripe. This stripe is hypothesized to reduce the amount of solar glare reflected into the eyes while foraging, thereby increasing hunting efficiency in bright conditions. Here, we use a novel, global-scale correlative approach to test this 'solar glare hypothesis' in peregrine falcons (Falco peregrinus), the most widespread falcon species, using web-sourced photographs from across the species' global range. We found that the size and prominence of the malar stripe were positively associated with average annual solar radiation, but not with other environmental variables, such as temperature and rainfall. Our results provide the first published evidence for the hypothesis that this plumage feature functions to reduce the amount of solar glare reflected into the falcon's eyes, thereby improving the ability to pinpoint and target agile prey in bright conditions.

The dark-ventral-patch of male red deer, a sexual signal that conveys the degree of involvement in rutting behavior

BackgroundIn polygynous mammals, signalling may play a decisive role in mating behavior, mediating the intensity of male fights and female mate choice. During the rutting season, male red deer may show a visible dark patch in their ventral fur. Recently, this patch has been suggested to act as a flexible sexual signal, due to its relationships with other variables such as age, body size, antler development, volatile compounds, or the competitive environment. The analysis of fur pigmentation at the ventral patch suggests that this might also visually indicate the male intrinsic predisposition to take part in mating competition.ResultsTo assess the possible role of this trait as a communicative signal related to mate competition, we used red deer behavioral observations during the rut in Doñana National Park (Spain) to examine the link between the degree of expression of the dark ventral patch and the rutting activity (assessed from both intra-and-inter-sexual behaviors). Consistent with our predictions, we found in a field study that males with large dark patches showed a higher frequency of rutting behaviors (mainly roaring and flehmen), more interactions with females, and attained larger harem sizes.ConclusionsThe dark ventral patch was a better predictor of male behavior than antler tines or territory holding, thus standing as a short-term indicator of male willingness to invest in mating competition.

A new species of Congrid eel, Ariosoma melanospilos sp. nov., from Indian waters with taxonomic description of A. dolichopterum (Congridae: Bathymyrinae)

A new species of congrid eel, Ariosoma melanospilos sp. nov., is described from two specimens collected as bycatch landings of deep-sea trawlers at Colachel fish landing centre, off Kanyakumari, the southwest coast of India. The new species is distinguishable from all the known congeners in having two spots on both sides of the mid-dorsal temporal region (vs. absent in all congeners) and a wide interbranchial width of 25.0–30.3% head length. The new species resembles Ariosoma meeki (Jordan & Snyder, 1900) in possessing the unique character of two dark patches at the posterior margin of the eye but can be readily distinguished by the presence of a fifth supraorbital pore and three pores as ascending branch of the infraorbital canal behind the eye, three supratemporal pores (vs. absent in A. meeki) and four black spots on the temporal region. Genetic analysis reveals that the new species is closely related to Ariosoma anale (Poey, 1860) and A. meeki forming a clade with a genetic distance of 20.5% and 19.6%, respectively. We also report Ariosoma dolichopterum Karmovskaya, 2015, for the first time from Indian waters with meristic and morphological characters.

COVID'19 - Future of India with Safety and Security Measures

A lot of awareness has been created by the government of India on the spread of the COVID-19 pandemic. Many precautions have been initiated by the Central government and followed by the state government. The entire country of India was unaware of what the consequences would be until it reached the country. Though thedisease broke into the world society during December 2019, there was not much impact on a huge country like India though it had its borders widespread with China. The economy was on the rise, and the country was about to become stable, and many growth activities were planned by both the central and state governments. Normal life was at ease before the outbreak of the pandemic. People across the country had been doing their daily activities without any hindrances. Hence, the paper presents the major economic conditions pre and post lockdown. It also covered people who were worst hit by the pandemic. However, light can be seen after a dark patch in the form of safety and security measures which are discussed in detail. Safety and security measures are the major things thata normal human being can do in such pandemics.

A RARE PRESENTATION OF DLE MASQUERADING AS BOWEN'S DISEASE: A CASE REPORT

Discoid Lupus Erythematosus (DLE) is a benign inammatory disorder of the skin that most frequently involves the face and scalp. It is characterized by asymptomatic, well dened, red, scaly patches of variable size, which heal with atrophy, scarring and pigmentary changes. Bowen's disease is a squamous cell carcinoma in situ of unknown etiology that occurs in both sun exposed and covered areas. It presents as well circumscribed, round to oval, pink or dark red scaly patches which may become hyperkeratotic, crusted or ulcerated.

Colletotrichum gloeosporioides s.l. causes an outbreak of anthracnose of cacao in Ghana

Outbreak of anthracnose of cacao (Theobroma cacao L.), covering an estimated total growing area of 248.47 hectares, occurred in parts of Ghana from July to October 2019. Disease samples were collected from the outbreak areas to isolate and identify the pathogen and establish its pathogenicity. Disease symptoms appeared on leaves as dark brown patches with yellow halo margins. Colletotrichum gloeosporioides s.l. was isolated from infected plant tissues and pathogenicity tests confirmed it as the causative agent. The disease was widespread in the Prestea-Huni Valley district of the Western Region, particularly in the Yareyeya community, where a 14.8-hectare farm was seriously affected. Anthracnose has long been known as a sporadic but minor disease of cacao in Ghana. The current shift in status and rapid spread of the disease from infected farms to new farms, though it may or may not be contiguous, cannot be readily explained. Application of copper fungicides, namely Nordox 75 WG (86% cuprous oxide), Champion (77% cupric hydroxide) and Royal Cop 50 WP (77% copper hydroxide) at 75 g, 100 g and 100 g, respectively, each in 15 litres of water, at 2-week intervals for four months, effectively managed the disease.

Description of a new toad of Megophrys Kuhl amp; Van Hasselt, 1822 (Amphibia: Anura: Megophryidae) from western Yunnan Province, China.

A new species of genus Megophrys from Gaoligong Mountains, Yunnan Province, China is described. Phylogenetic analyses based on mitochondrial DNA and nuclear DNA all clustered the new species as an independent clade nested into the subgenus Panophrys. The smallest genetic distance based on 16S rRNA gene between the new species and its congeners was 3.0%. The new species could be identified from its congeners by a combination of following characters: moderate body size (SVL 31.0-34.8 mm in males); vomerine ridge weak, vomerine teeth absent; dorsal skin relatively smooth; tongue slightly notched behind; tympanum rounded and relatively large, 0.54 times of eye length; a horn-like tubercle on edge of each upper eyelid small; tibio-tarsal articulation reaches middle eye when leg stretched forward; finger tips rounded, not expanded to small pad; toes with narrow fringes and rudimentary webbing; ventral hindlimbs semitransparent purplish with greyish white pigments; ventral body scattered with distinct dark patches in the middle.

Detection of Wakashio oil spill off Mauritius using Sentinel-1 and 2 data: Capability of sensors, image transformation methods and mapping.

Oil spill incidents contaminate water bodies, and damage the coastal and marine environment including coral reefs and mangroves, and therefore, monitoring the oil spills is highly important. This study discriminates the Wakashio oil spill, which occurred off Mauritius, located in the Indian Ocean on August 06, 2020 using the Sentinel-1 and 2 data acquired before, during and after the spill to understand the spreading of the spill and assess its impact on the coastal environment. The interpretation of VV polarization images of Synthetic-Aperture Radar (SAR) C-band (5.404GHz) of Sentinel-1 acquired between July 5 and September 3, 2020 showed the occurrence and distribution of oil spill as dark warped patches. The images of band ratios (5+6)/7, (3+4)/2, (11+12)/8 and 3/2, (3+4)/2, (6+7)/5 of the Sentinel-2 data detected the oil spill. The images of decorrelated spectral bands 4, 3 and 2 distinguished the very thick, thick and thin oil spills in a different tone and showed clearly their distribution over the lagoon and offshore, and the accumulation of spilled oil on the coral reefs and along the coast. The distribution of post-oil spill along the coast was interpreted using the images acquired after 21 August 2020. The accuracy of oil spill mapping was assessed by classifying the SAR-C data and decorrelated images of the MultiSpectral Instrument (MSI) data using the Parallelepiped supervised algorithm and confusion matrix. The results showed that the overall accuracy is on an average 91.72 and 98.77%, and Kappa coefficient 0.84 and 0.96, respectively. The satellite-derived results were validated with field studies. The MSI results showed the occurrence and spread of oil spill having different thicknesses, and supported the results of SAR. This study demonstrated the capability of Sentinel sensors and the potential of image processing methods to detect, monitor and assess oil spill impact on environment.

What Are These Dark Brown Patches on the Sole of a Boy’s Foot?

What Are These Dark Brown Patches on the Sole of a Boy’s Foot?

SAR Image Registration Based on ROEWA-Blocks and Multiscale Circle Descriptor

Given the imaging characteristics of synthetic aperture radar (SAR) images and the inherent speckle noise in them, scale-invariant feature transform based algorithms are unable to perform satisfactorily. To improve registration efficiency between SAR images, we propose a robust and efficient registration method with three main contributions. First, considering sudden dark patches appearing in SAR images, we propose the ratio of exponentially weighted average blocks to suppress the sudden dark patches and better adapt to different test images. This new operator called blocks of the ratio of exponentially weighted averages (ROEWA-B) divides the processing windows of ROEWA into blocks, which can not only reduce speckle noise but also retain more edge details compared to ROEWA when sudden dark patches appear. Second, for outlier removal, we present an approach using the minimum moment map to remove erroneous keypoints. Finally, based on the gradient location orientation histogram descriptor, we propose a novel multiscale circle descriptor, which combines scale change information to give weights to feature points at different scales. Experimental results for various thresholds and evaluations demonstrate the advantage and robustness of our method in registration.

Polycystic Ovary Syndrome - A Case Report

Polycystic ovary syndrome PCOS is a hormonal disorder common among women of reproductive age. It includes a set of symptoms due to elevated androgens male hormones in females Hyperandrogenemia. Signs and symptoms of PCOS include irregular or no menstrual periods excessive bleeding during the periods increased body and facial hair acne abdomen or pelvic pain inability to conceive and appearance of dark patches at the nape of neck thick and velvety skin. Associated conditions include type 2 diabetes obesity obstructive sleep apnea heart disease mood disorders and endometrial cancer. In this case study a 22-year-old female patient presented with the complaints of pimples and increased facial hair since five years. Associated complaints were nasal block cold and headache since three years. Clinical findings were recorded with respect to height weight body mass index and findings related to menstruation. She was treated with Ayurvedic purification therapy Vamana. Remarkable changes were noted after Ayurvedic purification therapy with reduction of pimples and appearance of no new lesions.nbsp

Billolivia lamdongensis (Gesneriaceae), a New Species from Vietnam

Billolivia lamdongensis Hareesh, T.A. Le & D.D. Nguyen sp. nova (Gesneriaceae) is described and illustrated from Central Highlands, Vietnam. It resembles B. vietnamensis but differs from the latter in having short hairs on the adaxial surface of the lamina; ovate-lanceolate bracts; linear calyx lobes 3/4 length of the corolla tube; a white corolla with a yellow throat and a dark purple patch between the upper lips on both surfaces; and fruits with pubescence all over.

The dark ventral patch: A bimodal flexible trait related to male competition in red deer.

Sexual signals play a central role in male-male competition in polygynous species. In red deer (Cervus elaphus), male’s ventral area become dark during the rutting season due to urine spraying behaviour and retains many chemical compounds potentially revealing individual features. Here we investigate the variation in size of this trait, exploring its relationship with age and male competitive features such as antlers or body size, as well as populational level of intrasexual competition for mates. We found that the size of the dark ventral patch followed a clearly bimodal distribution, i.e. males mostly expressed the full-size trait or just developed a very small one. For these two groups of males according to trait expression, the relationships of trait size with age and antler size differed. Populational level of intrasexual competition appeared to affect the relationship between antler size and the probability of a fully developed ventral patch. These results indicate that the trait encodes information on body size, antler size, age and populational level of mate competition, thus suggesting a role in signalling male’s competitive features and willingness to allocate reproductive effort within a particular season.

Ultrastructural morphological features of the hair in a sexual signal: the dark ventral patch of male red deer

AbstractChemical signals play a decisive role in communication in many mammal species. In red deer (Cervus elaphus), the dark ventral patch has recently been described as a male chemical signal involved in intrasexual competition. Morphological specializations of the hair of this area might contribute to retaining the volatile compounds found here. In this study, we examined differences in the ultrastructure between hair associated with the dark ventral patch and hairs from the dorsolateral region of the body as a control. We obtained a gallery of images from a scanning electron microscope to study the possible variation in the detailed anatomy as well as the surface and pattern of cuticular scales of hairs of the two body regions examined. In addition, we used a 2D‐3D microscope to measure hair diameter (thickness) and the shape and size of the cuticular scales. We found that the hairs of the dark ventral patch were narrower than those from the dorsolateral region. We also found a different cuticular scale pattern of the dark ventral patch hairs, suggesting a possible specialization for the retention of compounds associated with this chemical signal. Moreover, some intersexual differences in hair morphology also support this idea. This study shows, for the first time, the differentiation of hairs related to the dark ventral patch, which contributes to our better understanding of this chemical communication in red deer.

Pigmented Fungiform Papillae of the Tongue and Lingual Fimbriae as Single Presentation in Adult: A Case Report and Literature Review.

The normal variant in the oral mucosa is a nonpathological condition. Clinical examination must be carefully performed to avoid misdiagnosis as pathological condition. We reported two rare cases of pigmented fungiform papillae and lingual fimbria. Case 1 presented a 22-year-old Javanese man, with no systemic disease and several dark patches over the tongue for2 years. Case 2 presented a 21-year-old Javanese woman with dark patches over the dorsal and lateral of the tongue which had been known for over 4 to 5 months. Both patients had no systemic issues and there were no complaints about the patches. The dark patches, which appeared in both cases, were found together with linear small bumps on the ventral surface of the tongue and near the lingual frenulum. Further examination and specific treatment were not carried out, in accordance with the condition on the tongue.

Energy harvesting for electrochemical OER and solar photocatalysis via dual functional GO/TiO2-NiO nanocomposite

Highly efficient dual functional electrochemical and photocatalysts by incorporation of GO and TiO2 doped NiO composites have been developed. The prepared catalysts were subjected toward oxygen evolution reaction (OER) in electro catalytic water splitting and photocatalytic degradation of bromophenol blue (BPB). TiO2 doped NiO having monoclinic phase with GO is confirmed by XRD profile. The introduction of TiO2 into NiO matrix and addition of GO has reduced intensity of XRD peaks in composites. The morphological structures confirm fluffy NiO with small spherical dark patches of TiO2 nanoparticles which are dispersed randomly on broken sheets of GO in composite structure. UV–Vis spectra illustrated obvious band gap reduction (∼2.0–2.6 eV) in various GO/Ti-NiO composites with improvement in visible light absorption. The generation of Ti−Ni−C junction in composite samples is examined by FTIR and Raman analysis. In OER (1M KOH) 4.0 wt. % GO/Ti-NiO generated the small Tafel slope of ∼60 mVdec−1, low Rct∼4.1 Ω and high current density ∼70 mAcm−2 as compared to other samples. The composite materials govern OER process by Volmer-Heyrovsky mechanism. GO/Ti-NiO composite with 4.0 wt. % Ti shows the highest degradation (∼95 % )of BPB due to active surface sites generated by Ti−Ni−C linkages and interconnected conductive carbon materials of GO. Defective structure of GO provides favorable kinetics to the electro catalytic OER and supportive in enhancement of the electronic conduction. Ni2+ offers more active sites along with Ti4+ for OH−adsorption. Intermediate species of BPB have been identified by HPLC analysis. This work brings new insight for designing multifunctional materials for energy conversion and environmental remediation applications.