Shell sclerochronology and stable isotopes of the bivalve Anomalocardia flexuosa (Linnaeus, 1767) from southern Brazil: : implications for environmental and archaeological studies

We conduct the first stable isotopic and sclerochronological calibration of the bivalve Anomalocardia flexuosa (Linnaeus, 1767) in relation to environmental variables in a subtropical coastal area of southern Brazil. We investigate incremental shell growth patterns and δ18O and δ13C values of modern specimens collected alive from the Laguna Lagoonal System (LLS). As shells of Anomalocardia flexuosa are also the main components of pre-Columbian archaeological shell mounds and middens distributed along the Brazilian coastline, late Holocene archaeological specimens from a local shell mound (Cabeçuda) were selected to compare their stable carbon and oxygen isotopes with those of modern specimens. Shell growth increments, δ18O and δ13C values respond to a complex of environmental conditions, involving, for example, the effects of temperature and salinity. The isotopic information extracted from archaeological specimens from Cabeçuda shell midden in the LLS indirectly indicates that environmental conditions during the late Holocene were different from present day. In particular, intra-shell δ18O and δ13C values of archaeological shells reveal a stronger marine influence at 3 ka cal BP, which is in contrast to the seasonal freshwater/seawater balance that currently prevails at the LLS

Reconstituição paleoambiental da vegetação costeira na foz dos rios Santa Maria da Vitória e Jucu durante o holoceno médio e tardio, Estado do Espírito Santo, Brasil

Climate and sea level changes may have caused significant alterations in coastal morphology and mangrove distribution on the central coast of Espírito Santo State, Brazil. Therefore, this study aims to identify the dynamics of coastal vegetation during the middle and late Holocene, in the Santa Maria da Vitória and Jucu rivers. For this purpose, 14C dates, sedimentary data and pollen data were used, obtained from two sedimentary cores, called RSMV (340 cm) and JUCU (190 cm). During the middle Holocene, around 7245-7368 cal years BP, the relative sea level (SSL) was above the current level, resulting in the development of mangroves in the RSMV core region. However, around 2699-2787 cal years BP, with the regression of the SSL, the mangrove area moved to topographically lower regions. Another determining factor for the reduction of these areas during this period to date was human intervention. In the JUCU core region, mangrove forests were identified between 2188-2332 cal yr BP, initially colonized by Laguncularia. Thus, in this context, the dynamics of vegetation and sediments are associated with fluctuations in relative sea level and climate change throughout the Holocene.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorMudanças climáticas e no nível do mar podem ter provocado alterações significativas na morfologia costeira e na distribuição dos manguezais no litoral central do Estado do Espírito Santo, Brasil. Portanto, este trabalho pretende identificar a dinâmica da vegetação litorânea durante o Holoceno médio e tardio, nos rios Santa Maria da Vitória e Jucu. Para tal, foram utilizadas datações 14C, dados sedimentares e dados polínicos, obtidos a partir de dois testemunhos sedimentares, denominados RSMV (340cm) e JUCU (190cm). Durante o Holoceno médio, por volta de 7245-7368 anos cal AP, o nível relativo do mar (NRM) estava acima do nível atual, resultando no desenvolvimento de manguezal na região do testemunho RSMV. Entretanto, cerca de 2699-2787 anos cal AP, com a regressão do NRM, a área de manguezal se deslocou para regiões topograficamente mais baixas. Outro fator determinante para a redução dessas áreas durante esse período até o momento foi a intervenção humana. Na região do testemunho JUCU, identificou-se a instalação de manguezal em 2188-2332 anos cal AP inicialmente colonizado por Laguncularia. Assim, nesse contexto, a dinâmica da vegetação e dos sedimentos estão associadas com às flutuações do nível relativo do mar e às mudanças climáticas ao longo do Holoceno

Understanding Past and Present Vegetation Dynamics Using the Palynological Approach: An Introductory Discourse

Palynology is a multi-disciplinary field of science that deals with the study and application of extinct, [fossilised] and extant palynomorphs (pollen and spore) and other related microscopic biological entities in the environment. It is divided into palaeo- and actuo-palynology, and provides substantial proxies to understanding past and present vegetation dynamics respectively. With reference to the two geological principles of uniformitarianism and of the evolution of fauna/flora, the distribution of plant indicators across ecological zones, palynomorph morphology and pollen analysis, palynology can be used to identify the change in past and present local and regional vegetation and climate and humans impact on the environment. Other supportive areas of endeavour like radiocarbon dating, sedimentology, taphonomic processes and geomorphology can be used to triangulate inferences drawn from palynological data. Palynomorphs are made of outer cell walls embedded with an inert, complex and resistant biopolymeric signature (called sporopollenin) which helps to facilitate long term preservation in different environmental matrices under favourable conditions, hence its widespread applicability. Palynology have proven to very reliable in reconstructing past vegetation, decrypting essential honeybee plants and understanding the impact of climate on plant population using pollen analysis, for which is the basis for the application of palynology in environmental studies. The application of palynology in climate, vegetation and anthropogenic studies begins with the selection of matrix (sediments from lake, river, ocean, excavation, relatively intact soil profile, bee products), coring or collection of samples, subjection to a series of chemically aided digestion, separation, physical filtration, decanting, accumulating of palynomorphs, microscopic study and ends with the interpretation of recovered information. Literature review on the application of palynology for understanding vegetation and climate interactions is presented in this paper

Landscape analysis and land use evolution in the hydrographic basin of Barra Seca river, ES

Multitemporal analysis for monitoring land cover and use is an important tool for understanding the evolutionary dynamics of a region, assisting the knowledge on the environmental reality. This study aimed at mapping the land cover classes of the Barra Seca River basin, in northern Espírito Santo, obtained using the Bhattacharya algorithm supervised classification in 1985, 1996, 2006 and 2016. The land use and occupation map allowed characterizing quantitatively the areas identified in the basin map in 10 classes as follows water bodies, agriculture and grasses, dense tree cover, sparse tree cover, exposed soil, wetlands, urban areas, rocky outcrops, shade, and clouds. The landscape maps were obtained using the Patch Analyst extension. In the studied time interval, the land use and occupation in the basin changed little, with areas dominated mostly by agriculture and grasslands, followed by forests while the basin vegetation area also remained mostly unchanged. However, the quantitative analysis using landscape metrics indicates an increasing fragmentation and edge effect in the Barra Seca River basin

Malignant melanoma of the urethra: a rare histologic subdivision of vulvar cancer with a poor prognosis

Malignant melanoma of the urethra is a rare tumour that is difficult to diagnose and treat, resulting in a poor prognosis. In this paper, we present the case of a 65-year-old woman who was referred to a gynaecologist because of a urethral mass that mimicked a caruncle. The tumour was removed by local excision, and a pathological analysis revealed a malignant melanoma. Distal urethrectomy was performed after three months with no evidence of residual tumour. There was no evidence of disease at a six-year followup. In this paper, we compare the epidemiology, treatment, staging, and prognosis of vulvar cancer in general to malignant melanoma of the vulva in particular