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Mineral dust particles suspended in the atmosphere span more than three orders of magnitude in diameter, from <0.1 µm to more than 100 µm. This wide size range makes dust a unique aerosol species with the ability to interact with many aspects of the Earth system, including radiation, clouds, hydrology, atmospheric chemistry, and biogeochemistry. This review focuses on coarse and super-coarse dust aerosols, which we respectively define as dust particles with a diameter of 2.5–10 µm and 10–62.5 µm. We review several lines of observational evidence indicating that coarse and super-coarse dust particles are transported farther than previously expected and that the abundance of these particles is substantially underestimated in current global models. We synthesize previous studies that used observations, theories, and model simulations to highlight the impacts of coarse and super-coarse dust aerosols on the Earth system, including their effects on dust-radiation interactions, dust-cloud interactions, atmospheric chemistry, and biogeochemistry. Specifically, coarse and super-coarse dust aerosols produce a net positive direct radiative effect (warming) at the top of the atmosphere and can modify temperature and water vapor profiles, influencing the distribution of clouds and precipitation. In addition, coarse and super-coarse dust aerosols contribute a substantial fraction of ice-nucleating particles, especially at temperatures above –23 °C. They also contribute a substantial fraction to the available reactive surfaces for atmospheric processing and the dust deposition flux that impacts land and ocean biogeochemistry by supplying important nutrients such as iron and phosphorus. Furthermore, we examine several limitations in the representation of coarse and super-coarse dust aerosols in current model simulations and remote-sensing retrievals. Because these limitations substantially contribute to the uncertainties in simulating the abundance and impacts of coarse and super-c

Even though desert dust is the most abundant aerosol by mass in Earth s atmosphere, the relative contributions of the world s major source regions to the global dust cycle remain poorly constrained. This problem hinders accounting for the potentially large impact of regional differences in dust properties on clouds, the Earth s energy balance, and terrestrial and marine biogeochemical cycles. Here, we constrain the contribution of each of the world s main dust source regions to the global dust cycle. We use an analytical framework that integrates an ensemble of global aerosol model simulations with observationally informed constraints on the dust size distribution, extinction efficiency, and regional dust aerosol optical depth (DAOD). We obtain a dataset that constrains the relative contribution of nine major source regions to size-resolved dust emission, atmospheric loading, DAOD, concentration, and deposition flux. We find that the 22 29 Tg (1 standard error range) global loading of dust with a geometric diameter up to 20 um is partitioned as follows: North African source regions contribute 50% (11 15 Tg), Asian source regions contribute 40% (8 13 Tg), and North American and Southern Hemisphere regions contribute 10% (1.8 3.2 Tg). These results suggest that current models on average overestimate the contribution of North African sources to atmospheric dust loading at 65 %, while underestimating the contribution of Asian dust at 30 %. Our results further show that each source region s dust loading peaks in local spring and summer, which is partially driven by increased dust lifetime in those seasons. We also quantify the dust deposition flux to the Amazon rainforest to be 10 Tg yr1, which is a factor of 2 3 less than inferred from satellite data by previous work that likely overestimated dust deposition by underestimating the dust mass extinction efficiency. The data obtained in this paper can be used to obtain improved constraints on dust impacts on clouds, climat

Even though desert dust is the most abundant aerosol by mass in Earth s atmosphere, atmospheric models struggle to accurately represent its spatial and temporal distribution. These model errors are partially caused by fundamental difficulties in simulating dust emission in coarseresolution models and in accurately representing dust microphysical properties. Here we mitigate these problems by developing a new methodology that yields an improved representation of the global dust cycle. We present an analytical framework that uses inverse modeling to integrate an ensemble of global model simulations with observational constraints on the dust size distribution, extinction efficiency, and regional dust aerosol optical depth.We then compare the inverse model results against independent measurements of dust surface concentration and deposition flux and find that errors are reduced by approximately a factor of 2 relative to current model simulations of the Northern Hemisphere dust cycle. The inverse model results show smaller improvements in the less dusty Southern Hemisphere, most likely because both the model simulations and the observational constraints used in the inverse model are less accurate. On a global basis, we find that the emission flux of dust with a geometric diameter up to 20 um (PM20) is approximately 5000 Tg yr1, which is greater than most models account for. This larger PM20 dust flux is needed to match observational constraints showing a large atmospheric loading of coarse dust. We obtain gridded datasets of dust emission, vertically integrated loading, dust aerosol optical depth, (surface) concentration, and wet and dry deposition fluxes that are resolved by season and particle size. As our results indicate that this dataset is more accurate than current model simulations and the MERRA-2 dust reanalysis product, it can be used to improve quantifications of dust impacts on the Earth system.

Multi-wavelength in-situ surface scattering and absorption properties of PM2.5 and PM10 Saharan dust particles were measured during a dust emission field campaign performed in L’Bour (M’Hamid, Morocco) in September 2019 (Figure 1) within the FRAGMENT project (FRontiers in dust minerAloGical coMposition and its Effects upoN climaTe). The main goal of FRAGMENT is to understand and constrain the global mineralogical composition of dust along with its effects upon climate. Among other issues, the field campaigns are devoted to understanding the size distribution and mineralogy of emitted dust and its relationship with the parent soil properties. A wide variety of instruments for dust characterization were deployed including a radiometer, a fully equipped meteorological tower, cascade impactors, saltation sensors, OPC aerosol spectrometers, a polar nephelometer and an aethalometer, among others.

Introduction Diagnosis and pathological classification of insulinomas are challenging. Aim To characterize localization of tumors, surgery outcomes, and histopathology in patients with insulinoma. Methods Patients with surgically resected sporadic insulinoma were included. Results Eighty patients were included. Seven had a malignant tumor. A total of 312 diagnostic examinations were performed: endoscopic ultrasonography (EUS; n = 59; sensitivity, 70%), MRI (n = 33; sensitivity, 58%), CT (n = 55; sensitivity, 47%), transabdominal ultrasonography (US; n = 45; sensitivity, 40%), somatostatin receptor imaging (n = 17; sensitivity, 29%), 18F-fluorodeoxyglucose positron emission tomography/CT (n = 1; negative), percutaneous transhepatic venous sampling (n = 10; sensitivity, 90%), arterial stimulation venous sampling (n = 20; sensitivity, 65%), and intraoperative US (n = 72; sensitivity, 89%). Fourteen tumors could not be visualized. Invasive methods were used in 7 of these 14 patients and localized the tumor in all cases. Median tumor size was 15 mm (range, 7 to 80 mm). Tumors with malignant vs benign behavior showed less staining for insulin (3 of 7 vs 66 of 73; P = 0.015) and for proinsulin (3 of 6 vs 58 of 59; P < 0.001). Staining for glucagon was seen in 2 of 6 malignant tumors and in no benign tumors (P < 0.001). Forty-three insulinomas stained negative for somatostatin receptor subtype 2a. Conclusion Localization of insulinomas requires many different diagnostic procedures. Most tumors can be localized by conventional imaging, including EUS. For nonvisible tumors, invasive methods may be a useful diagnostic tool. Malignant tumors showed reduced staining for insulin and proinsulin and increased staining for glucagon.

Motor activity in healthy young humans displays intrinsic fluctuations that are scale-invariant over a wide range of time scales (from minutes to hours). Human postmortem and animal lesion studies showed that the intact function of the suprachiasmatic nucleus (SCN) is required to maintain such scale-invariant patterns. We therefore hypothesized that scale invariance is degraded in patients treated for suprasellar tumors that compress the SCN. To test the hypothesis, we investigated 68 patients with nonfunctioning pituitary macroadenoma and 22 patients with craniopharyngioma, as well as 72 age-matched healthy controls (age range 21.0–70.6 years). Spontaneous wrist locomotor activity was measured for 7 days with actigraphy, and detrended fluctuation analysis was applied to assess correlations over a range of time scales from minutes to 24 h. For all the subjects, complex scale-invariant correlations were only present for time scales smaller than 1.5 h, and became more random at time scales 1.5–10 h. Patients with suprasellar tumors showed a larger decrease in correlations at 1.5–10 h as compared to healthy controls. Within healthy subject, gender and age >33 year were associated with attenuated scale invariance. Conversely, activity patterns at time scales between 10 and 24 h were significantly more regular than all other time scales, and this was mostly associated with age. In conclusion, scale invariance is degraded in healthy subjects at the ages of >33 year as characterized by attenuation of correlations at time scales 1.5–10 h. In addition, scale invariance was more degraded in patients with suprasellar tumors as compared to healthy subjects.

Item does not contain fulltext, Podosomes are actin-rich adhesion structures that depend on Arp2/3-complex-based actin nucleation. We now report the identification of the formins FHOD1 and INF2 as novel components and additional actin-based regulators of podosomes in primary human macrophages. FHOD1 surrounds the podosome core and is also present at podosome-connecting cables, whereas INF2 localizes at the podosome cap structure. Using a variety of microscopy-based methods; including a semiautomated podosome reformation assay, measurement of podosome oscillations, FRAP analysis of single podosomes, and structured illumination microscopy, both formins were found to regulate different aspects of podosome-associated contractility, with FHOD1 mediating actomyosin contractility between podosomes, and INF2 regulating contractile events at individual podosomes. Moreover, INF2 was found to be a crucial regulator of podosome de novo formation and size. Collectively, we identify FHOD1 and INF2 as novel regulators of inter- and intra-structural contractility of podosomes. Podosomes thus present as one of the few currently identified structures which depend on the concerted activity of both Arp2/3 complex and specific formins and might serve as a model system for the analysis of complex actin architectures in cells.