By means of the SAETTA 3D lightning mapping array, the total lightning activity has been detected in a 240 km × 240 km square domain centred on the island of Corsica located in the West Mediterranean ...basin, and characterized by a maritime and mountainous environment, with a complex and relatively high relief. The study period covers the months from April to December of the 6 years from 2014 to 2019. Observations are reported with a horizontal resolution of 1 km and a vertical resolution of 0.1 km in terms of density of VHF sources emitted by lightning, and of number of lightning day, in plane- and vertical- projections. Vertical distributions of VHF sources are also provided monthly for the whole period and over the full domain. These 3D long term observations show that the number of lightning days is more important on the main relief of the island. The density of VHF sources exhibits a sharp maximum over the confluence area of the 3 main valleys in the center of the northern part of the island, characterized by a recurrent and vertically well developed lightning activity. The period from 11:00 UTC to 14:00 UTC in July, and in a lesser extent in June and August, is at the origin of this density maximum. This behavior is thus due to a diurnal convection. The whole lightning activity is characterized by 2 maxima in June and September. The first one is linked with the diurnal convection in phase with the maximum elevation of the Sun. The second one must be due to usual large-scale organized thunderstorm events of the fall season. The vertical distribution of VHF sources exhibits an increase in the number of VHF sources from April to August at all altitudes, as well as an increase in the altitude of the main upper peak (from 5.8 km to 10 km) and of the secondary lower peak (from 4.2 km to 6.7 km) of this distribution. From August to December, the opposite evolution appears, except that October is characterized by a strong anomaly with a single intense lower peak at 5.5 km, apparently due to 2 strong events corresponding to anomalously electrified thunderstorms. Several of these anomalously electrified thunderstorms (negative dipoles) are reported. They are all characterized by the movement of cloud cells spatially small and relatively undeveloped vertically propagating from southwest to northeast and associated with a strong transport of desert dust from the African continent. The analysis of the meteorological environment of some of the studied events allows concluding that in each of the studied cases elevated convection was triggered, above the relatively dry atmospheric boundary layer characterized by a strong convective inhibition. The low cloud liquid water content which is a key parameter of the non-inductive charging process is probably a good candidate to explain the anomalous electrification of these events.
•First 3D lightning climatology in a maritime and mountainous region.•Maximum of lightning activity mainly due to spring diurnal convection between 11:00 and 14:00 UTC.•The most intense lightning activity is located at the crossroads of the 3 main valleys.•Occurrences of anomalously electrified thunderstorms correspond to southern flows with strong transport of African dust•Convection of anomalously electrified thunderstorms triggered above the boundary layer with strong convective inhibition
Objective
Functional magnetic resonance imaging (fMRI) visualizes brain structures at increasingly higher resolution and better signal-to-noise ratio (SNR) as field strength increases. Yet, mapping ...the blood oxygen level dependent (BOLD) response to distinct neuronal processes continues to be challenging. Here, we investigated the characteristics of 7 T-fMRI compared to 3 T-fMRI in the human brain beyond the effect of increased SNR and verified the benefits of 7 T-fMRI in the detection of tiny, highly specific modulations of functional connectivity in the resting state following a motor task.
Methods
18 healthy volunteers underwent two resting state and a stimulus driven measurement using a finger tapping motor task at 3 and 7 T, respectively. The SNR for each field strength was adjusted by targeted voxel size variation to minimize the effect of SNR on the field strength specific outcome. Spatial and temporal characteristics of resting state ICA, network graphs, and motor task related activated areas were compared. Finally, a graph theoretical approach was used to detect resting state modulation subsequent to a simple motor task.
Results
Spatial extensions of resting state ICA and motor task related activated areas were consistent between field strengths, but temporal characteristics varied, indicating that 7 T achieved a higher functional specificity of the BOLD response than 3 T-fMRI. Following the motor task, only 7 T-fMRI enabled the detection of highly specific connectivity modulations representing an “offline replay” of previous motor activation. Modulated connections of the motor cortex were directly linked to brain regions associated with memory consolidation.
Conclusion
These findings reveal how memory processing is initiated even after simple motor tasks, and that it begins earlier than previously shown. Thus, the superior capability of 7 T-fMRI to detect subtle functional dynamics promises to improve diagnostics and therapeutic assessment of neurological diseases.
Resting state (RS) connectivity has been increasingly studied in healthy and diseased brains in humans and animals. This paper presents a new method to analyze RS data from fMRI that combines ...multiple seed correlation analysis with graph-theory (MSRA). We characterize and evaluate this new method in relation to two other graph-theoretical methods and ICA. The graph-theoretical methods calculate cross-correlations of regional average time-courses, one using seed regions of the same size (SRCC) and the other using whole brain structure regions (RCCA). We evaluated the reproducibility, power, and capacity of these methods to characterize short-term RS modulation to unilateral physiological whisker stimulation in rats. Graph-theoretical networks found with the MSRA approach were highly reproducible, and their communities showed large overlaps with ICA components. Additionally, MSRA was the only one of all tested methods that had the power to detect significant RS modulations induced by whisker stimulation that are controlled by family-wise error rate (FWE). Compared to the reduced resting state network connectivity during task performance, these modulations implied decreased connectivity strength in the bilateral sensorimotor and entorhinal cortex. Additionally, the contralateral ventromedial thalamus (part of the barrel field related lemniscal pathway) and the hypothalamus showed reduced connectivity. Enhanced connectivity was observed in the amygdala, especially the contralateral basolateral amygdala (involved in emotional learning processes). In conclusion, MSRA is a powerful analytical approach that can reliably detect tiny modulations of RS connectivity. It shows a great promise as a method for studying RS dynamics in healthy and pathological conditions.
Worldwide, acute, and chronic pain affects 20% of the adult population and represents an enormous financial and emotional burden. Using genome-wide neuronal-specific RNAi knockdown in
Drosophila, we ...report a global screen for an innate behavior and identify hundreds of genes implicated in heat nociception, including the α2δ family calcium channel subunit
straightjacket (
stj). Mice mutant for the
stj ortholog
CACNA2D3 (
α2δ3) also exhibit impaired behavioral heat pain sensitivity. In addition, in humans,
α2δ3 SNP variants associate with reduced sensitivity to acute noxious heat and chronic back pain. Functional imaging in
α2δ3 mutant mice revealed impaired transmission of thermal pain-evoked signals from the thalamus to higher-order pain centers. Intriguingly, in
α2δ3 mutant mice, thermal pain and tactile stimulation triggered strong cross-activation, or synesthesia, of brain regions involved in vision, olfaction, and hearing.
Display omitted
► Whole-genome in vivo RNAi screen for noxious heat avoidance in
Drosophila ► Identification of
α2-δ as a “pain” gene in fly ► Mouse and human homologs of
α2-δ (
α2δ3) are also pain genes ► Loss of
α2δ3 in mice results in sensory cross-activation, or synesthesia
Worldwide, acute, and chronic pain affects 20% of the adult population and represents an enormous financial and emotional burden. Using genome-wide neuronal-specific RNAi knockdown in Drosophila, we ...report a global screen for an innate behavior and identify hundreds of genes implicated in heat nociception, including the alpha 2 delta family calcium channel subunit straightjacket (stj). Mice mutant for the stj ortholog CACNA2D3 ( alpha 2 delta 3) also exhibit impaired behavioral heat pain sensitivity. In addition, in humans, alpha 2 delta 3 SNP variants associate with reduced sensitivity to acute noxious heat and chronic back pain. Functional imaging in alpha 2 delta 3 mutant mice revealed impaired transmission of thermal pain-evoked signals from the thalamus to higher-order pain centers. Intriguingly, in alpha 2 delta 3 mutant mice, thermal pain and tactile stimulation triggered strong cross-activation, or synesthesia, of brain regions involved in vision, olfaction, and hearing.
•Castleman disease is an overgrowth of lymphatic cells, usually in the chest or abdomen.•Multicentric Castleman disease affects lymphatic cells throughout the body.•HHV-8 and HIV have been associated ...with multicentric Castleman disease.•Unicentric Castleman disease affects a single group of lymph nodes.•Centricity is considered the most important indicator of patient outcomes.
Castleman disease (CD) is a rare lymphocytic disorder. Unicentric CD (UCD) has an excellent long-term prognosis after surgical excision; however, multicentric CD (MCD) has a severe clinical course with poor outcomes.
We analyzed the clinical presentation of 28 patients treated at a single institution from 1995 to 2017. Demographics, clinical variables, anatomical site, centricity, histopathology, immunochemistry, and surgical approach were reviewed. We evaluated the 5-year recurrence and survival for patients with UCD and MCD.
Of the 28 patients, 57 % (n = 16) were female, with a mean age of 41.6 ± 15.6 years. CD was asymptomatic in 57 % (n = 16) of patients, 21 % (n = 6) presented with local symptoms such as pain, and 21 % (n = 6) of patients also had systemic symptoms, including weight loss and fever. CD was unicentric in 64 % (n = 18) and multicentric in 36 % (n = 10). The hyaline vascular variant was noted in 57 % (n = 16) of the tumors, plasmacytoid variant in 36 % (n = 10), and mixed variants in 7% (n = 2) of tumors. Anatomical distributions included: head and neck (20 %), thorax and axilla (24 %), retroperitoneal (13 %), abdominopelvic (30 %) regions, and other (13 %). Complete surgical resection was performed in 95 % of patients with UCD. Surgical biopsy and medical therapy were provided to all patients with MCD. The recurrence rate for UCD and MCD was 6 % (n = 1) and 14 % (n = 1), respectively. The five-year disease-free survival rate for UCD was 95 % (n = 19) and MCD was 33 % (n = 2). We found 100 % survival in patients with UCD and histology demonstrating the HV variant.
CD is rare and often misdiagnosed due to the absence of specific clinical symptoms. Surgeons should include CD in their differential diagnoses when evaluating patients with lymph node hyperplasia. Surgery can be curative in nearly all patients with UCD. Patients with MCD require a combination of surgical therapy, chemotherapy, and immunotherapy; however, cytoreductive surgery benefits for patients with MCD have not been established.
It has been described that the replication regulator protein geminin is rapidly degraded at the end of mitosis and newly expressed at the beginning of the next S phase in the metazoan cell cycle. We ...have performed experiments to investigate the synthesis of geminin in cycling human HeLa cells. The levels of geminin-mRNA vary only modestly during the cell cycle with a 2–3-fold higher mRNA level at the G1/S phase transition, whereas newly synthesized geminin can only be detected in post-G1 phases. Surprisingly, geminin, once synthesized, does not remain stable, but is turned over during S phase with a half-life of 3–4
h. We also show that geminin becomes phosphorylated as S phase proceeds and identify by MALDI mass spectrometry two specific major phosphorylation sites.
PDF
