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Moonmilk-type deposits exemplify carbonated Martian analogues existing in the subsurface of Earth, an endokarstic speleothem with a possible biochemical origin composed principally by carbonates, mainly huntite and dolomite. In this work, samples of moonmilk located in Nerja Cave (southern Spain) have been studied by LIBS with the aim of identifying carbon of biogenic origin by establishing a relationship between a molecular emission indicator, CN signal, and the organic carbon content. The characterization of this kind of carbonate deposit with a multiple mineralogical composition has been completed using scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction techniques for qualitative and semi-quantitative analysis. The information attained from LIBS regarding energy thresholds and time-resolved kinetics of CN emissions provides useful insight into the identification of different molecular emitters, namely organic and inorganic CN, depending on the laser irradiance and time settings conditions. These promising results are of application in the search and identification of biosignatures in upcoming planetary missions with astrobiological purposes. [Display omitted] • Analysis of natural moonmilk speleothems by LIBS. • Ability of LIBS to detect molecular emission in karstic environments. • Correlation between optical CN emission and organic carbon content in carbonate rocks. • Differentiation of organic carbon and inorganic carbon by time-resolved LIBS. • Application in the identification of biosignatures in upcoming astrobiological missions. [ABSTRACT FROM AUTHOR]

This study shows the utilization of the air CO 2 exhaled by a very high number of visitors in the Nerja Cave as both a tracer and an additional tool to precisely evaluate the air circulation through the entire karst system, which includes non-touristic passages, originally free of anthropogenic CO 2 . The analysis of the temporal - spatial evolution of the CO 2 content and other monitoring data measured from January 2015 to December 2016 in the Nerja-Pintada system, including air microbiological controls, has allowed us to define a new general ventilation model, of great interest for the conservation of the subterranean environment. During the annual cycle four different ventilation regimes and two ventilation modes ( UAF-mode and DAF-mode ) exist which determine the significance of the anthropogenic impact within the caves. During the winter regime, the strong ventilation regime and the airflow directions from the lowest to the highest entrance ( UAF-mode ) contribute to the rapid elimination of anthropogenic CO 2 , and this affects the whole karstic system. During the summer regime the DAF-mode ventilation (with airflows from the highest to the lowest entrances) is activated. Although the number of visitors is maximum and the natural ventilation of the karstic system is the lowest of the annual cycle, the anthropogenic impact only affects the Tourist Galleries . The transitional ventilation regimes - spring and autumn - are the most complex of the annual cycle, with changing air-flow directions (from UAF-mode to DAF-mode and vice versa ) at diurnal and poly diurnal scale, which conditions the range of the anthropogenic impact in each sector of the karst system. The activation of the DAF-mode has been observed when the temperature difference between the external and air cave is higher than 5 °C. [ABSTRACT FROM AUTHOR]

Following the declaration of the COVID-19 pandemic, the Spanish Government restricted non-essential movements of all citizens and closed all public spaces, such as the Nerja Cave, until May 31, 2020. This particular condition of the closure of the cave provided a unique opportunity to study the micro-climate conditions and carbonate precipitation in this tourist cave without the presence of visitors. Our results show the significant effect of visitors on the air isotopic signature of the cave and on the genesis of the extensive dissolution features affecting the carbonate crystals formed in the tourist sector of the cave, alerting us to the possible corrosion of the speleothems located there. The movement of visitors within the cave also favours the mobilisation of aerial fungi and bacterial spores and their subsequent sedimentation simultaneously with the abiotic precipitation of carbonates from the drip water. The traces of these biotic elements could be the origin of the micro-perforations previously described in the carbonate crystals formed in the tourist galleries of the cave, but they are subsequently enlarged due to abiotic dissolution of the carbonates through these weaker zones., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The integrated use of multi-isotopic ( 87 Sr/ 86 Sr, δ 13 C-DIC, δ 2 H-H 2 O, δ 18 O-H 2 O) and hydrochemical data was applied in the highly anthropized Guadalhorce river basin, southern Spain, to improve the knowledge about water contamination sources and processes and to achieve improved water resource management. The results obtained highlight the importance of the use of isotopes as tracers of pollutants. DIC, δ 2 H-H 2 O, δ 18 O-H 2 O and δ 13 C-DIC allowed differentiating two water recharge end members: direct rainwater, infiltrated into the upper and lower detritic aquifers of the sub-basins, and the Guadalhorce dam system, which act as a source in some groundwater and surface waters of the lower sub-basin. 87 Sr/ 86 Sr data supported the existing conclusions in relation to pollution sources in the study area. The Triassic basement (evaporites) of the carbonate and detritic aquifers of the basin generally controls the natural 87 Sr/ 86 Sr composition in waters of the upper sub-basin. Only one groundwater sample reflects the influence of a human organic source (sewage) in its composition. On the other hand, mixing of human inorganic (fertilizers and detergents) strontium sources is required to explain the 87 Sr/ 86 Sr contents of the lower sub-basin waters. Discriminating the use of domestic detergents as another anthropogenic source of strontium and sulphate in waters is a novel finding in this research. The conclusions reached can be extrapolated to other anthropized basins., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

An evaluation is made of the clinical and histological parameters of 650 cases of spinocellular epithelioma. The statistical analysis shows tumor relapse to be related to tumor size, evolution time, relapse following previous treatments, earlier cutaneous lesions, Broders' grading, acantholysis, inflammatory infiltrate and type of treatment applied.

We present a new case of porokeratosis plantaris palmaris et disseminata (PPPD), observe in it a histological picture of cornoid lamella in palms, soles, arms, legs and trunk. In this dermatosis, mediant lectins and involucrin to establish keratinocytes alteration. The immunohistochemical studies have reveals not normal formation in the envelope cornea, and fundamentally D-galactose show a marked diminution in the cell membrane.