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In this study, we revise the index that quantifies the North African Dipole Intensity (NAFDI), and explain its relationship with the Saharan Heat Low (SHL) and mid-latitude Rossby waves. We find outstanding similarities of meteorological patterns associated with the positive NAFDI and the SHL West-phase on the one hand, and with the negative NAFDI and the SHL East-Phase, on the other hand. We introduce the daily NAFDI index and the daily SHL West-East Displacement Index (SHLWEDI). The Pearson correlation coefficient between the daily SHLWEDI 1-day lagged and the daily NAFDI for the period 1980–2013 20 June–17 September is fairly high (r = 0.77). The correlation reduces to 0.69 if the SHLWEDI is not lagged. We observe that the SHL West-phase is significantly more frequent than the SHL East-phase, and that the SHL is more intense during its East-phase. We find positive aerosol optical depth (AOD) anomalies in the Western Sahara during positive NAFDI/SHL West-phase, and negative AOD anomalies in the central and eastern Sahara during negative NAFDI/SHL East-phase. A significant positive (negative) NE-SW axis AOD anomaly over the Subtropical North Atlantic for positive (negative) NAFDI is found. Remarkable patterns of positive (negative) AOD anomalies over the tropical Atlantic and the Central-Western Mediterranean during negative (positive) NAFDI are observed. The impact of mid-latitude Rossby waves on NAFDI variations depends on both the amplitude and phase of the Rossby wave at 200–300 hPa, which is quantified in this study by the daily Zonal Wind Anomaly at 300 hPa over South Morocco (ZWA300), and the penetration of the Rossby wave into the lower troposphere, quantified by the daily Omega at 500 hPa over Northwest Algeria (O500). The correlation of both ZWA300 and O500 with NAFDI is significant: 0.48 and 0.53, respectively, when we apply 5-day running means to the time series before calculating the correlation coefficients, and increases to 0.66 when a multi-linear regression is performed. The results suggest that ZWA300 drives almost one day in advance the NAFDI, whereas O500 might be ahead respect to NAFDI less than 12 hours. The power spectra of the NAFDI, SHL, ZWA300 and O500 times series in the intermediate time scale range (between 10 and 30 days) show 10 especially intense NAFDI spectral peaks, most of them also present in the SHLWEDI spectrum, finding that for many of the NAFDI/SHLWEDI peaks there is associated an O500 and/or ZWA300 peak. Our results indicate that the modes of oscillation of both the NAFDI and the SHL are driven by those mid-latitudes Rossby waves that go deep enough into the lower troposphere imposing their perturbation to the background meteorological fields. A comprehensive top-down conceptual model is introduced to explain the relationships between the NAFDI, the SHL and the mid-latitude Rossby waves and their impact in dust mobilization and transport in Northern Africa. [ABSTRACT FROM AUTHOR]

In the framework of the World Meteorological Organisation's Sand and Dust Storm Warning Advisory and Assessment System, we evaluated the predictions of five state-of-the-art dust forecast models during an intense Saharan dust outbreak affecting Western and Northern Europe in April 2011. We assessed the capacity of the models to predict the evolution of the dust cloud with lead-times of up to 72 h using observations of aerosol optical depth (AOD) from the Aerosol Robotic Network (AERONET) and the Moderate Resolution Imaging Spectroradiometer (MODIS), and dust surface concentrations from a ground-based measurement network. In addition, the predicted vertical dust distribution was evaluated with vertical extinction profiles from the Cloud and Aerosol Lidar with Orthogonal Polarization (CALIOP). To assess the diversity in forecast capability among the models, the analysis was extended to wind field (both surface and profile), synoptic conditions, emissions and deposition fluxes. Models predict the onset and evolution of the AOD for all analysed lead-times. On average, differences among the models are larger than differences among lead-times for each individual model. In spite of large differences in emission and deposition, the models present comparable skill for AOD. In general, models are better in predicting AOD than near-surface dust concentration over the Iberian Peninsula. Models tend to underestimate the long-range transport towards Northern Europe. Our analysis suggests that this is partly due to difficulties in simulating the vertical distribution dust and horizontal wind. Differences in the size distribution and wet scavenging efficiency may also account for model diversity in long-range transport. [ABSTRACT FROM AUTHOR]

In the present work, atmospheric mineral dust from a MACC-II short reanalysis run for two years (2007-2008), has been evaluated over Northern Africa and Middle East using satellite aerosol products (from MISR, MODIS and OMI satellite sensors), ground-based AERONET data, in-situ PM10 concentrations from AMMA, and extinction vertical profiles from two ground-based lidars and CALIOP. The MACC-II aerosol optical depth (AOD) spatial and temporal (seasonal and interannual) variability shows good agreement with those provided by satellite sensors. The capability of the model to reproduce AOD, Ångström exponent (AE) and dust optical depth (DOD) from daily to seasonal time-scale is quantified over twenty-six AERONET stations located in eight geographically distinct regions by using statistical parameters. Overall DOD seasonal variation is fairly well simulated by MACC-II in all regions, although the correlation is significantly higher in dust transport regions than in dust source regions. The ability of MACC-II in reproducing dust vertical profiles has been assessed by comparing seasonal averaged extinction vertical profiles simulated by MACC-II under dust conditions with corresponding extinction profiles obtained with lidar instruments at M'Bour and Santa Cruz de Tenerife, and with CALIOP. We find a good agreement in dust layers structures and averaged extinction vertical profiles between MACC-II, the lidars and CALIOP above the marine boundary layer from 1 to 6 km. Surface dust daily mean concentrations from MACC-II reanalysis has been evaluated with daily averaged PM10 at three monitoring stations of the Sahelian Dust Transect. MACC-II correctly reproduces daily to interannual surface dust concentration variability, although it underestimates daily and monthly means all year long, especially in winter and early spring (dry season). MACC-II reproduces well the dust variability recorded along the station-transect which reflects the variability in dust emission by different Saharan sources, but fails in reproducing the sporadic and very strong dust events associated to mesoscale convective systems during the wet season. [ABSTRACT FROM AUTHOR]

In late March 2018, a large part of the Eastern Mediterranean experienced an extraordinary episode of African dust, one of the most intense in recent years, here referred to as the "Minoan Red" event. The episode mainly affected the Greek island of Crete, where the highest aerosol concentrations over the past 15 yeas were recorded, although impacts were also felt well beyond this core area. Our study fills a gap in dust research by assessing the multi-sectoral impacts of sand and dust storms and their socioeconomic implications. Specifically, we provide a multi-sectoral impact assessment of Crete during the occurrence of this exceptional African dust event. During the day of the occurrence of the maximum dust concentration in Crete, i.e. March 22nd, 2018, we identified impacts on meteorological conditions, agriculture, transport, energy, society (including closing of schools and cancellation of social events), and emergency response systems. As a result, the event led to a 3-fold increase in daily emergency responses compare to previous days associated with urban emergencies and wildfires, a 3.5-fold increase in hospital visits and admissions for Chronic Obstructive Pulmonary Disease (COPD) exacerbations and dyspnoea, a reduction of visibility causing aircraft traffic disruptions (eleven cancellations and seven delays), and a reduction of solar energy production. We estimate the cost of direct and indirect effects of the dust episode, considering the most affected socio-economic sectors (e.g. civil protection, aviation, health and solar energy production), to be between 3.4 and 3.8 million EUR for Crete. Since such desert dust transport episodes are natural, meteorology-driven and thus to a large extent unavoidable, we argue that the efficiency of actions to mitigate dust impacts depends on the accuracy of operational dust forecasting and the implementation of relevant early warning systems for social awareness., 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 The Authors. Published by Elsevier B.V. All rights reserved.)

Recent studies have found increases in the cardiovascular mortality rates during poor air quality events due to outbreaks of desert dust. In Tenerife, we collected (2014-2017) data in 829 patients admitted with a heart failure diagnosis in the Emergency Department of the University Hospital of the Canaries. In this region, concentrations of PM 10 and PM 2.5 are usually low (~20 and 10 µg/m 3 ), but they increase to 360 and 115 μg/m 3 , respectively, during Saharan dust events. By using statistical tools (including multivariable logistic regressions), we compared in-hospital mortality of patients with heart failure and exposure to PM 10 and PM 2.5 during dust and no-dust events. We found that 86% of in-hospital heart failure mortality cases occurred during Saharan dust episodes that resulted in PM 10 > 50 µg/m 3 (interquartile range: 71-96 µg/m 3 ). A multivariate analysis showed that, after adjusting for other covariates, exposure to Saharan dust events associated with PM 10 > 50 µg/m 3 was an independent predictor of heart failure in-hospital mortality (OR = 2.79, 95% CI (1.066-7.332), p = 0.03). In conclusion, this study demonstrates that exposure to high Saharan dust concentrations is independently associated with in-hospital mortality in patients with heart failure.

The ribosomal protein S6 kinase 1 (S6K1) is emerging as a common downstream target of signalling by hormones and nutrients such as insulin and amino acids. Here, we have investigated how amino acids signal through the S6K1 pathway. First, we found that a commercial anti-phospho-Thr389-S6K1 antibody detects an 80-90 kDa protein that is rapidly phosphorylated in response to amino acids. Unexpectedly, this phosphorylation was insensitive to both mTOR and PI-3 kinase inhibitors, and knockdown experiments showed that this protein was not S6K1. Looking for candidate targets of this phosphorylation, we found that amino acids stimulated phosphorylation of RSK and MSK kinases at residues that are homologous to Thr389 in S6K1. In turn, these phosphorylations required the activity of either p38 or ERK MAP kinases, which could compensate for each other. Moreover, we show that these MAP kinases are also needed for the amino acid-induced phosphorylation of S6K1 at Thr421/Ser424, as well as for that of S6K1 substrate, the S6 ribosomal protein. Consistent with these results, concomitant inhibition of p38 and ERK pathways also antagonised the well-known effects of amino acids on the process of autophagy. Altogether, these findings demonstrate a previously unknown role for MAP kinases in amino acid signalling.

The Regulator of Chromosome Condensation 1 (RCC1) was identified over 20 years ago as a critical cell cycle regulator. By analyzing its amino acid sequence, RCC1 was found to consist of seven homologous repeats of 51-68 amino acid residues, which were later shown to adopt a seven-bladed beta-propeller fold. Since the initial identification of RCC1, a number of proteins have been discovered that contain one or more RCC1-like domains (RLDs). As we show here, these RCC1 superfamily proteins can be subdivided in five subgroups based on structural criteria. In recent years, a number of studies have been published regarding the functions of RCC1 superfamily proteins. From these studies, the emerging picture is that the RLD is a versatile domain which may perform many different functions, including guanine nucleotide exchange on small GTP-binding proteins, enzyme inhibition or interaction with proteins and lipids. Here, we review the available structural and functional data on RCC1 superfamily members, paying special attention to the human proteins and their involvement in disease.

To be able to separate and analyze giant proteins and small proteins in the same electrophoretic gel, we have used a continuous SDS-PAGE gel formed by the combination of a low-percentage acrylamide gel and a gradient SDS-PAGE gel that we have named LAG gel. To get a good resolution for proteins of more than 200 kDa, we used an acrylamide/bisacrylamide ratio of 80:1 in the low-percentage acrylamide gel. To successfully resolve proteins in the 5-200 kDa range, we used a conventional 6-15% SDS-PAGE gradient gel with the standard acrylamide/bisacrylamide ratio of 40:1. We show that the LAG system can be successfully used in general applications of SDS-PAGE electrophoresis such as proteomics and immunobloting techniques. Thus, using this continuous LAG gel, it is possible to simultaneously analyze giant proteins, such as HERC1 and dynein, big proteins like clathrin heavy chain and small proteins like ARF. The LAG system has a good resolution, low cost, and high reproducibility. Moreover, to simultaneously analyze all proteins saves time. All these characteristics, together with the use of a standard apparatus found in any biochemistry laboratory, make the LAG system an easy tool to use.