Dark Spots (dark + spot)

Distribution by Scientific Domains


Selected Abstracts


Clinical pathologic correlations for diagnosis and treatment of nail disorders

DERMATOLOGIC THERAPY, Issue 1 2007
Olympia I. Kovich
ABSTRACT:, Clinicopathologic correlation is crucial to the correct diagnosis of disorders of the nail unit. This chapter will explore four common clinical scenarios and how pathology can help differentiate between their various etiologies. These include: dark spot on the nail plate (melanin versus heme), subungual hyperkeratosis (onychomycosis versus psoriasis), longitudinal melanonychia (benign versus malignant), and verrucous papule (verruca versus squamous cell carcinoma). Consideration must be given to both when to perform a biopsy and the location of the biopsy site, which must be based on an understanding of the origin of the changes. An overarching principle is that lesions within the same differential diagnosis may be present concomitantly, such as malignant melanoma of the nail unit associated with hemorrhage. Therefore, even with a biopsy-proven diagnosis, the clinician must always monitor lesions of the nail unit for appropriate response to treatment and consider an additional biopsy for recalcitrant lesions. [source]


On violence as the negativity of the Durkheimian: between anomie, sacrifice and effervescence

INTERNATIONAL SOCIAL SCIENCE JOURNAL, Issue 2006
S. Romi Mukherjee
In this introductory article I contextualise, historically and theoretically, the rapport between Durkheimianism and violence. Telescoping Durkheimian theories of anomie, sacrifice and effervescence, I demonstrate how both Durkheim and Mauss, arguably the most prominent members of the French School of Sociology, found themselves constantly reflecting on violence in all its forms while never outlining an explicit theory of violence. Violence was thus the dark spot of their enterprises, at once omnipresent but disavowed. I weave together the various fragments of their oeuvres that illuminate the ground of the Durkheimian theory of violence and also examine the precise reasons for its lack of clear theorisation. I conclude with some remarks on Durkheim and fascism. Therefore, this article serves to supplement and set the stage for the articles that appear in this volume, pieces that in their own ways grapple with similar problematics while also moving beyond them and charting new directions in Durkheimian studies. [source]


THE REACTION NORM FOR ABDOMINAL PIGMENTATION AND ITS CURVE IN DROSOPHILA MEDIOPUNCTATA DEPEND ON THE MEAN PHENOTYPIC VALUE

EVOLUTION, Issue 1 2009
Felipe Rocha
The idea of a general independence between the phenotypic plasticity and the mean value of a trait is, presently, a consensus. Here, we use the reaction norm of abdominal pigmentation (number of dark spots) of Drosophila mediopunctata in response to temperature, to test this idea. We raised eight strains, bearing two different chromosomal inversions and with varying mean phenotypic values, under 11 temperatures in a thermal gradient to test for predictions concerning mean phenotypic values, chromosomal inversions, and reaction norms. Our results revealed a strong effect of different phenotypic groups and no effect of different karyotypes on reaction norms. Moreover, we found a significant negative correlation between mean phenotypic value and the curvature of the reaction norms, revealing a high dependency of the reaction norm shape on mean phenotypic value. These results clearly reject the idea of genetic independence between mean value and phenotypic plasticity, and may indicate a pattern of correlation, which may include results from other traits and species, with an importance that has not been fully appreciated. [source]


INVOLVEMENT OF PEROXIDASE AND POLYPHENOL OXIDASE IN MANGO SAP-INJURY

JOURNAL OF FOOD BIOCHEMISTRY, Issue 5 2002
K. SABY JOHN
ABSTRACT Sap (latex) that oozes out from mango during harvest, upon contact with the fruit, causes dark spots (sap-injury) on the peel and reduces consumer acceptance and shelf-life of fruit. In this investigation different components responsible for sap-injury were identified. Mango saps from four Indian varieties were collected and separated into aqueous and nonaqueous phases. Whole sap, aqueous phase and nonaqueous phase were tested for their ability to cause sap-injury (browning) on mangoes. The nonaqueous phase caused maximum injury and the extent of injury caused by nonaqueous phases from different varieties was varied. Limonene, ocimene and ,-myrcene, the major terpenoids identified in saps of Indian varieties, caused injury. Similar type of injury on mangoes was also caused by organic solvents. Damage on Totapuri mango fruit was significantly lower compared to other varieties, whereas Totapuri nonaqueous phase caused injury on all other varieties. The peel of Totapuri variety had very low level of polyphenol oxidase, peroxidase and polyphenols compared to other varieties. Thus, a clear relation was found between the peel polyphenol oxidase, peroxidase activities, the polyphenol content in the peel and the extent of injury. Further, nonaqueous phase applied on peels previously heat-treated at 95C for 5 min, neither caused injury nor showed any enzyme activity. Thus, the results indicated that the terpenoid components of sap and polyphenol oxidase, peroxidase, polyphenols of peel are involved in sap-injury. [source]


Post-common-envelope binaries from SDSS , I. 101 white dwarf main-sequence binaries with multiple Sloan Digital Sky Survey spectroscopy

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2007
A. Rebassa-Mansergas
ABSTRACT We present a detailed analysis of 101 white dwarf main-sequence binaries (WDMS) from the Sloan Digital Sky Survey (SDSS) for which multiple SDSS spectra are available. We detect significant radial velocity variations in 18 WDMS, identifying them as post-common-envelope binaries (PCEBs) or strong PCEB candidates. Strict upper limits to the orbital periods are calculated, ranging from 0.43 to 7880 d. Given the sparse temporal sampling and relatively low spectral resolution of the SDSS spectra, our results imply a PCEB fraction of ,15 per cent among the WDMS in the SDSS data base. Using a spectral decomposition/fitting technique we determined the white dwarf effective temperatures and surface gravities, masses and secondary star spectral types for all WDMS in our sample. Two independent distance estimates are obtained from the flux-scaling factors between the WDMS spectra, and the white dwarf models and main-sequence star templates, respectively. Approximately one-third of the systems in our sample show a significant discrepancy between the two distance estimates. In the majority of discrepant cases, the distance estimate based on the secondary star is too large. A possible explanation for this behaviour is that the secondary star spectral types that we determined from the SDSS spectra are systematically too early by one to two spectral classes. This behaviour could be explained by stellar activity, if covering a significant fraction of the star by cool dark spots will raise the temperature of the interspot regions. Finally, we discuss the selection effects of the WDMS sample provided by the SDSS project. [source]


Speckled lentiginous naevus: which of the two disorders do you mean?

CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 2 2009
R. Happle
Summary Speckled lentiginous naevus (synonym: naevus spilus) no longer represents one clinical entity, but rather, two different disorders can be distinguished. Naevus spilus maculosus is consistently found in phacomatosis spilorosea, whereas naevus spilus papulosus represents a hallmark of phacomatosis pigmentokeratotica. The macular type is characterized by dark speckles that are completely flat and rather evenly distributed on a light brown background, resembling a polka-dot pattern. In contrast, naevus spilus papulosus is defined by dark papules that are of different sizes and rather unevenly distributed, reminiscent of a star map. Histopathologically, the dark spots of naevus spilus maculosus show a ,jentigo' pattern and several nests of melanocytes involving the dermoepidermal junction at the tips of the papillae, whereas most of the dark speckles of naevus spilus papulosus are found to be dermal or compound melanocytic naevi. The propensity to develop Spitz naevi appears to be the same in both types of speckled lentiginous naevus, whereas development of malignant melanoma has been reported far more commonly in naevus spilus maculosus. [source]