This paper presents a meteorological analysis of a storm that produced two jets, four gigantic jets (GJ), and a starter, which were observed by two radars as well as the Kennedy Space Center ...4‐Dimensional Lightning Surveillance System on 3 August 2013 in Central Florida. The work is the first application of dual polarization data to a jet‐producing storm and is the fifth case related to a tropical disturbance. The storm environment is consistent with the moist tropical paradigm that characterizes about three quarters of the surface and aircraft observed jet and GJ events. The most unstable (MU) convective available potential energy is not unusual for Florida summer convection and is below the climatological mean for these events. An unusual speed shear layer is located near the storm equilibrium level (EL) and the storm exhibits a tilted structure with CGs displaced upshear. The turbulence, as measured by the eddy dissipation rate, is extreme near the storm top during the event window, consistent with the GJ mixing hypothesis. The individual events are collocated with, and track along, the center axis of the divergent outflow at the EL and occur within the region of the coldest GOES IR temperatures—placing the events within the overshoot. The dual polarization data indicate a deep graupel column, extending above the mixed phase layer, to a 13 km altitude.
Key Points
Upper level shear may enhance mixing at storm top
Mixing and divergence at storm top are significant
Traditional shear metrics may not be applicable to jet storms
We report on the first search for Terrestrial Gamma‐ray Flashes (TGFs) from altitudes where they are thought to be produced. The Airborne Detector for Energetic Lightning Emissions (ADELE), an array ...of gamma‐ray detectors, was flown near the tops of Florida thunderstorms in August/September 2009. The plane passed within 10 km horizontal distance of 1213 lightning discharges and only once detected a TGF. If these discharges had produced TGFs of the same intensity as those seen from space, every one should have been seen by ADELE. Separate and significant nondetections are established for intracloud lightning, negative cloud‐to‐ground lightning, and narrow bipolar events. We conclude that TGFs are not a primary triggering mechanism for lightning. We estimate the TGF‐to‐flash ratio to be on the order of 10−2 to 10−3 and show that TGF intensities cannot follow the well‐known power‐law distribution seen in earthquakes and solar flares, due to our limits on the presence of faint events.
Key Points
TGFs are not associated with most lightning flashes
Therefore TGFs are not an important lightning trigger
There is no large population of “mini” TGFs
The detection rate for identifying the underlying mutation in neurocutaneous syndromes is affected by the sensitivity of the mutation test and the heterogeneity of the disease based on the diagnostic ...criteria. Neurofibromatosis type (NF1) has been defined for 29years by the National Institutes for Health (NIH) criteria which include ≥6 Café au Lait macules (CAL) as a defining criterion. The discovery of SPRED1 as a cause of Legius syndrome which is manifested by CAL, freckling and learning difficulties has introduced substantial heterogeneity to the NIH criteria.
We have defined the sensitivity of comprehensive RNA analysis on blood of presumed NF1 patients meeting NIH criteria with at least one nonpigmentary criterion and determined the proportion of children with ≥6 CAL and no family history that has an NF1 or SPRED1 genetic variant. RNA analysis was carried out from 04/2009–12/2015 on 361 NF1 patients.
A presumed causative NF1 mutation was found in 166/171 (97.08%–95% CI 94.56–99.6%) of familial cases and 182/190 (95.8%–95% CI 92.93–98.65%) sporadic de novo cases. Two of thirteen (15%) mutation negative individuals had dysembryoplastic neuroepithelial tumour (DNET) compared to 2/348 (0.6%) with an NF1 variant (p=0.007). No SPRED1 variants were found in the thirteen individuals with no NF1 variant. Of seventy-one individuals with ≥6 CAL and no non-pigmentary criterion aged 0–20years, 47 (66.2%) had an NF1 variant six (8.5%) a SPRED1 variant and 18 (25.3%) no disease causing variant. Using the 95.8% detection rate the likelihood of a child with ≥6 CAL having constitutional NF1 drops from 2/3 to 1/9 after negative RNA analysis.
RNA analysis in individuals with presumed NF1 has high sensitivity and includes a small subset with DNET without an NF1 variant. Furthermore negative analysis for NF1/SPRED1 provides strong reassurance to children with ≥6 CAL that they are unlikely to have NF1.
•RNA testing for NF1 mutations has very high sensitivity (c.96%) and is significantly more sensitive than DNA testing.•Mosaicism is not a major feature in those with classical NF1.•Around two thirds of children with just 6 or more café au lait spots have NF1, 8% Legius syndrome.•Patients with normal RNA testing who meet NF1 criteria but also have a DNET may have a fault in a yet to be identified gene.
Identifying the underlying genetic mutation is of benefit to patients and their families as it clarifies the diagnosis, can give information on the likely disease course and allow predictive testing in pregnancy and early childhood. The present study has shown that testing of blood RNA has very high sensitivity (96%) and allows substantial reassurance to parents whose children have multiple Café au lait birthmarks that they are unlikely to have the poorer outcomes of NF1 if they test negative. Furthermore the study suggests that a different mechanism may underlie the association of NF1 features and a rare benign brain tumour called DNET.
Rare de novo mutations represent a significant cause of idiopathic developmental delay (DD). The use of next‐generation sequencing (NGS) has boosted the identification of de novo mutations in an ...increasing number of novel genes. Here we present 3 unrelated children with de novo loss‐of‐function (LoF) mutations in QRICH1, diagnosed through trio‐based exome sequencing. QRICH1 encodes the glutamine‐rich protein 1, which contains 1 caspase activation recruitment domain and is likely to be involved in apoptosis and inflammation. All 3 children had speech delay, learning difficulties, a prominent nose and a thin upper lip. In addition, 2 of them had mildly raised creatine kinase (CK) and 1 of them had autism. Despite their small number, the patients had a relatively consistent pattern of clinical features suggesting the presence of a QRICH1‐associated phenotype. LoF mutations in QRICH1 are suggested as a novel cause of DD.
The characteristics of thunderstorms that produce terrestrial gamma‐ray flashes (TGFs) observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) are determined using ...climatological and meteorological data. RHESSI observed TGFs follow diurnal, seasonal, and geographic patterns that are very similar to those of thunderstorms confirming, in part, that these events are directly connected to thunderstorm activity. The TGF producing thunderstorms are shown to be closely associated with tall (ranging from 13.6 km to 17.3 km) tropical thunderstorm systems, a finding that is consistent with theoretical expectations from models of relativistic breakdown that relate the source region to the spectral signatures observed by RHESSI. Unlike sprites, there appears to be no predilection for TGFs to occur with large thunderstorm complexes. Rather, TGF producing thunderstorms are shown to range in areal extent by several orders of magnitude. Analysis of a single TGF event within the Mozambique Channel indicates an elevated mixed phase (both liquid water and ice present) level of approximately 6 km which is consistent with the climatological findings.
As a result of exome-based sequencing work performed by the DDD study, de novo variants in CNOT3 have emerged as a newly recognised cause of a developmental disorder. This paper describes molecular ...and clinical details of 16 probands with developmental disorders and de novo CNOT3 variants. It is the first such description of the developmental phenotype associated with CNOT3 variants. Eight of these cases were discovered as part of the DDD study, while the other eight were found as a result of large-scale sequencing work performed by other groups. A highly specific phenotype was not recognised in these 16 cases. The most consistent phenotypic features seen in subjects with de novo variants in CNOT3 were hypotonia, relatively small stature, developmental delay, behavioural problems and intellectual disability. There is no easily recognisable facial phenotype, but some common dysmorphic features such as anteverted nares, thin upper lip and low set eyebrows were shared among some of the probands. Haploinsufficiency appears to be the most likely mechanism of action, with eight cases found to have protein-truncating variants. Of the other eight cases (all missense variants), three share an amino acid substitution at the same position which may therefore represent an important functional domain.
CHN is genetically heterogeneous and its genetic basis is difficult to determine on features alone. CNTNAP1 encodes CASPR, integral in the paranodal junction high molecular mass complex. Nineteen ...individuals with biallelic variants have been described in association with severe congenital hypomyelinating neuropathy, respiratory compromise, profound intellectual disability and death within the first year. We report 7 additional patients ascertained through exome sequencing. We identified 9 novel CNTNAP1 variants in 6 families: three missense variants, four nonsense variants, one frameshift variant and one splice site variant. Significant polyhydramnios occurred in 6/7 pregnancies. Severe respiratory compromise was seen in 6/7 (tracheostomy in 5). A complex neurological phenotype was seen in all patients who had marked brain hypomyelination/demyelination and profound developmental delay. Additional neurological findings included cranial nerve compromise: orobulbar dysfunction in 5/7, facial nerve weakness in 4/7 and vocal cord paresis in 5/7. Dystonia occurred in 2/7 patients and limb contractures in 5/7. All had severe gastroesophageal reflux, and a gastrostomy was required in 5/7. In contrast to most previous reports, only one patient died in the first year of life. Protein modelling was performed for all detected CNTNAP1 variants. We propose a genotype-phenotype correlation, whereby hypomorphic missense variants partially ameliorate the phenotype, prolonging survival. This study suggests that biallelic variants in CNTNAP1 cause a distinct recognisable syndrome, which is not caused by other genes associated with CHN. Neonates presenting with this phenotype will benefit from early genetic definition to inform clinical management and enable essential genetic counselling for their families.
The terrestrial gamma ray flash (TGF) is an emission of highly energetic radiation produced by or at least in close association with lightning. Previous investigations attempted to isolate the ...production mechanisms and production altitude(s) of TGFs as well as macrophysical characteristics, while thunderstorm microphysical characteristics were largely ignored. This investigation into thunderstorms and their hydrometeor and flash characteristics utilize temporal and spatial coincident satellite passes between the Reuven Ramaty High Energy Solar Spectroscopic Imager and the Tropical Rainfall Measuring Mission to determine the bulk (or footprint) microphysical properties of two types of study events, the thunderstorm complexes which are associated with TGFs (TGF case) and the thunderstorm complexes which did not produce a TGF detected by Reuven Ramaty High Energy Solar Spectroscopic Imager during the pass (non‐TGF case). Results are presented for two different comparison methods. The first case utilizes geographic region weighted by TGF distribution, and the second is based on TGF percentage of occurrence when compared to total flash count of data set. Results show that the associated storms around the TGF location possess differences in the hydrometeor concentrations: cloud liquid water, cloud ice, precipitation water, and precipitation ice. These results take place at different levels of the atmosphere, including the mixed phase region. Additionally, results will show that TGFs are a consistent percentage of observed flashes as the rate of TGFs as a function of Lightning Imaging Sensor flash count is relatively constant.
Key Points
Hydrometeor characteristics of TGF thunderstorms
Hydrometeor characteristics of non‐TGF storms
TGF‐related storms have higher hydrometeor content
On 21 August 2009, the Airborne Detector for Energetic Lightning Emissions (ADELE), an array of six gamma‐ray detectors, detected a brief burst of gamma rays while flying aboard a Gulfstream V jet ...near two active thunderstorm cells. The duration and spectral characteristics of the event are consistent with the terrestrial gamma ray flashes (TGFs) seen by instruments in low Earth orbit. A long‐duration, complex +IC flash was taking place in the nearer cell at the same time, at a distance of ∼10 km from the plane. The sferics that are probably associated with this flash extended over 54 ms and included several ULF pulses corresponding to charge moment changes of up to 30 C km, this value being in the lower half of the range of sferics associated with TGFs seen from space. Monte Carlo simulations of gamma ray propagation in the Earth's atmosphere show that a TGF of normal intensity would, at this distance, have produced a gamma ray signal in ADELE of approximately the size and spectrum that was actually observed. We conclude that this was the first detection of a TGF from an aircraft. We show that because of the distance, ADELE's directional and spectral capabilities could not strongly constrain the source altitude of the TGF but that such constraints would be possible for TGFs detected at closer range.
Key Points
A terrestrial gamma ray flash has been observed from an aircraft for the first time
This terrestrial gamma ray flash (TGF) was associated with an unusual +IC flash
Compton scattering makes it hard to identify TGF source altitude at >5 km distance
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