Links between aerosol radiative forcing and rain characteristics: Stratiform and convective precipitation.

The radiative forcing before and after rain events was studied between 12 February 2016 and 14 March 2017 in León, Spain. For this purpose, the radiative forcing fluxes were calculated using the Radiative Transfer Model Global Atmospheric ModEl (RTM GAME). After the application of a set of selection criteria (based on the availability of AERONET data, rain characteristics and lightning maps), 16 stratiform rain events were identified, concentrated in spring and winter, and 15 convective rain events were found concentrated in spring and summer. Rainfall events were grouped according to the atmospheric forcing (ΔFATM) before rain: "low" or "high" (lower or higher than 30 W m-2). The threshold has been set at this value because it is the mean ΔFATM of all the selected events before rain. There were significant statistical differences between stratiform and convective events in rain duration, mean raindrop diameter and parameters a and b of radar reflectivity Z and rainfall intensity R relationship (Z = a Rb). When comparing "low" and "high" groups, raindrop diameter was similar in stratiform (0.51 ± 0.08 vs 0.48 ± 0.12 mm) and convective events (0.96 ± 0.98 vs 0.83 ± 0.63 mm), registering higher values for the latter. In stratiform events, the rain scavenging effect on aerosol particles is clearly observed in the "high" group with a decrease of radiative forcing of -27.0 ± 25.3%, and to a lesser extent, in the "low" group, probably because of a lower aerosol load in the atmosphere. In stratiform events, the mode of the raindrop size gamma distribution presented statistical differences between "low" (0.25 ± 0.13 mm) and "high" (0.35 ± 0.05 mm) groups. We claim that this points towards a relationship between radiative forcing before rain and the specific characteristics of rainfall measured at ground level. This study increases our knowledge on the important role of rainwater as a clean agent of the atmosphere and its impact on climate (through radiative forcing).

Unusual winter Saharan dust intrusions at Northwest Spain: Air quality, radiative and health impacts.

Saharan air masses can transport high amounts of mineral dust particles and biological material to the Iberian Peninsula. During winter, this kind of events is not very frequent and usually does not reach the northwest of the Peninsula. However, between 21 and 22 February 2016 and between 22 and 23 February 2017, two exceptional events were registered in León (Spain), which severely affected air quality. An integrative approach including: i) typical synoptic conditions; ii) aerosol chemical composition; iii) particle size distributions; iv) pollen concentration; v) aerosol optical depth (AOD); vi) radiative forcing and vii) estimation of the impact of aerosols in the respiratory tract, was carried out. In the global characterization of these events, the exceedance of the PM10 daily limit value, an increase in the coarse mode and a rise in the iron concentration were observed. On the 2016 event, an AOD and extinction-related Ångström exponent clearly characteristic of desert aerosol (1.1 and 0.05, respectively) were registered. Furthermore, pollen grains not typical of flowering plants in this period were identified. The chemical analysis of the aerosol from the 2017 event allowed us to confirm the presence of the main elements associated with mineral sources (aluminum, calcium, and silica concentrations). An increase in the SO42-, NO3- and Cl- concentrations during the Saharan dust intrusion was also noted. However, in this event, there was no presence of atypical pollen types. The estimated dust radiative forcing traduced a cooling effect for surface and atmosphere during both events, corroborated by trends of radiative flux measurements. The estimated impact on the respiratory tract regions of the high levels of particulate matter during both Saharan dust intrusions showed high levels for the respirable fraction.

Skin involvement in chronic myelomonocytic leukaemia as a predictor of transformation into acute myeloid leukaemia.

We report on the case of a patient with myelodysplastic syndrome (MDS) who presented with leukaemia cutis preceding development of acute myeloid leukaemia. Leukaemic infiltration of the skin should be considered an early manifestation of leukaemic transformation and an indicator of poor prognosis in MDS.

Pseudoporfiria por naproxeno / Naproxene-induced pseudoporphyria

No disponible

Follicular mycosis fungoides: presentation of a case and review of the literature.

Follicular mycosis fungoides is a rare variant of mycosis fungoides (MF). Structural-wise there are several acneiform lesions made up of comedones, cysts and hyperkeratosis. The main histological finding is atypical lymphocytic infiltration around follicular structures, without epidermotropism. The association with follicular mucinosis is widely discussed in the literature. We report a case of follicular (MF) and review the cases published to date.

Methanethiol: a morphogenetic factor produced from L-methionine by Phomopsis viticola Sacc.

Phomopsis viticola produces methanethiol on a synthetic medium enriched with L-methionine (MMGS). The growth rate is comparable, during 12 days of culture, to that on the same medium without L-methionine (MGS). Only sterile bodies are formed on MMGS and no pycnidia appeared. The morphogenetic effect of MMGS medium is attached to the volatile methanethiol produced from L-methionine introduced into the medium. This volatile product is identified using several different methods of analysis. The roles of the reactive sulfhydryl groups and of the metabolism of elemental sulfur of P. viticola in the differentiation processes are discussed.

[The role of cysteine in the detoxification of an herbicide]. / Le rôle de la cystéine dans la détoxification d'un herbicide.

The methyl 2-chloro-3 (4-chlorophenyl) propionate is quickly hydrolysed through coleoptiles of wheat (coleoptile test). Then, depending on the concentration of the compounds, one observes mainly a further degradation (at 0,01 mM) of the acid or conjugation (at 0,1 mM) of it with cystein in vivo. This second type of physiological neutralisation appears to be more efficient than the catabolism which give derivatives of benzoic acid.

Elemental sulfur: accumulation in different species of fungi.

Sulfur, in elemental form, is present in several fungi especially in self-inhibited and resting structures such as dormant spores and sclerotia. The possible importance of sulfur in fungal spore dormancy is discussed.