A Novel Mutation in the Upstream Open Reading Frame of the CDKN1B Gene Causes a MEN4 Phenotype

PubMed ID: 23555276This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Contrasting dynamics of electrons and protons in the near-Earth plasma sheet during dipolarization

The fortunate location of Cluster and the THEMIS P3 probe in the near-Earth plasma sheet (PS) (at X similar to -7-9- R-E) allowed for the multipoint analysis of properties and spectra of electron and proton injections. The injections were observed during dipolarization and substorm current wedge formation associated with braking of multiple bursty bulk flows (BBFs). In the course of dipolarization, a gradual growth of the B-Z magnetic field lasted similar to 13 min and it was comprised of several B-Z pulses or dipolarization fronts (DFs) with duration 50 keV) electron fluxes - the injection boundary - was observed in the PS simultaneously with the dipolarization onset and it propagated dawnward along with the onset-related DF. The subsequent dynamics of the energetic electron flux was similar to the dynamics of the magnetic field during the dipolarization. Namely, a gradual linear growth of the electron flux occurred simultaneously with the gradual growth of the B-Z field, and it was comprised of multiple short (similar to few minutes) electron injections associated with the B-Z pulses. This behavior can be explained by the combined action of local betatron acceleration at the B-Z pulses and subsequent gradient drifts of electrons in the flux pile up region through the numerous braking and diverting DFs. The nonadiabatic features occasionally observed in the electron spectra during the injections can be due to the electron interactions with high-frequency electromagnetic or electrostatic fluctuations transiently observed in the course of dipolarization. On the contrary, proton injections were detected only in the vicinity of the strongest B-Z pulses. The front thickness of these pulses was less than a gyroradius of thermal protons that ensured the nonadiabatic acceleration of protons. Indeed, during the injections in the energy spectra of protons the pronounced bulge was clearly observed in a finite energy range similar to 70-90 keV. This feature can be explained by the nonadiabatic resonant acceleration of protons by the bursts of the dawn-dusk electric field associated with the B-Z pulses

Survey of Legionella

Members of the Gram-negative genus Legionella are typically found in freshwater environments, with the exception of L. longbeachae, which is present in composts and potting mixes. When contaminated aerosols are inhaled, legionellosis may result, typically as either the more serious pneumonia Legionnaires’ disease or the less severe flu-like illness Pontiac fever. It is presumed that all species of the genus Legionella are capable of causing disease in humans. As a followup to a prior clinical study of legionellosis in rural Thailand, indigenous soil samples were collected proximal to cases’ homes and workplaces and tested for the presence of legionellae by culture. We obtained 115 isolates from 22/39 soil samples and used sequence-based methods to identify 12 known species of Legionella represented by 87 isolates

Environmental and biological factors are joint drivers of mercury biomagnification in subarctic lake food webs along a climate and productivity gradient

Subarctic lakes are getting warmer and more productive due to the joint effects of climate change and intensive land-use practices (e.g. forest clear-cutting and peatland ditching), processes that potentially increase leaching of peat- and soil-stored mercury into lake ecosystems. We sampled biotic communities from primary producers (algae) to top consumers (piscivorous fish), in 19 subarctic lakes situated on a latitudinal (69.0-66.5 degrees N), climatic (+3.2 degrees C temperature and +30% precipitation from north to south) and catchment land-use (pristine to intensive forestry areas) gradient. We first tested how the joint effects of climate and productivity influence mercury biomagnification in food webs focusing on the trophic magnification slope (TMS) and mercury baseline (THg baseline) level, both derived from linear regression between total mercury (log10THg) and organism trophic level (TL). We examined a suite of environmental and biotic variables thought to explain THg baseline and TMS with stepwise generalized multiple regression models. Finally, we assessed how climate and lake productivity affect the THg content of top predators in subarctic lakes. We found biomagnification of mercury in all studied lakes, but with variable TMS and THg baseline values. In stepwise multiple regression models, TMS was best explained by negative relationships with food chain length, climate-productivity gradient, catchment properties, and elemental C:N ratio of the top predator (full model R2 = 0.90, p < 0.001). The model examining variation in THg baseline values included the same variables with positive relationships (R2 = 0.69, p = 0.014). Mass standardized THg content of a common top predator (1 kg northern pike, Esox lucius) increased towards warmer and more productive lakes. Results indicate that increasing eutrophication via forestry-related land-use activities increase the THg levels at the base of the food web and in top predators, suggesting that the sources of nutrients and mercury should be considered in future bioaccumulation and biomagnification studies. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).Peer reviewe

Theoretical Analysis of the Adaptive System for Suppression of the Interference Concentrated on a Spectrum

The object of research is the process of interference suppression in a passive radiometric receiver, centered over the interference spectrum, with a random or varying frequency. Noise immunity can be increased by means of special circuits preventing the receiver from overloading and using differences in the characteristics of useful signals and interference to suppress the latter. As a rule, the frequency of noise oscillation is never accurately known and, in addition, the actual interference is never purely harmonic. Therefore, it became necessary to theoretically consider the degree of interference suppression by the input circuit of the radiometer at an unknown value of the interference frequency and the finite width of the spectrum, and also theoretically substantiate possible ways of constructing adaptive devices for suppressing real narrow-band noise.An expression is obtained for the suppression coefficient of the interference concentrated on a spectrum, which shows that the interference will be suppressed automatically for the optimal choice of the parameters ka, τ, T of the servo system.In the paper, a functional diagram of a radiometric receiver is presented, which uses an adaptive system to suppress the spectrum-centered interference. The adaptive system is based on the inclusion in the radiometric receiver circuit of additional compensating circuit interference. The interference compensating circuit makes it possible to increase the sensitivity of the receiver to 10-20 W with an accuracy of 0.1 ºC and a response rate of 2...4 s. In addition to interference suppression, the compensating link after the intermediate frequency amplifier is provided with interference suppression and an input circuit. In this case, the overall amplification in the noise immunity of the radiometric receiver in comparison with the compensating receiver, as calculations for typical characteristics show, will not be worse than 30 dB

Genomic heterogeneity differentiates clinical and environmental subgroups of Legionella pneumophila sequence type 1.

Legionella spp. are the cause of a severe bacterial pneumonia known as Legionnaires' disease (LD). In some cases, current genetic subtyping methods cannot resolve LD outbreaks caused by common, potentially endemic L. pneumophila (Lp) sequence types (ST), which complicates laboratory investigations and environmental source attribution. In the United States (US), ST1 is the most prevalent clinical and environmental Lp sequence type. In order to characterize the ST1 population, we sequenced 289 outbreak and non-outbreak associated clinical and environmental ST1 and ST1-variant Lp strains from the US and, together with international isolate sequences, explored their genetic and geographic diversity. The ST1 population was highly conserved at the nucleotide level; 98% of core nucleotide positions were invariant and environmental isolates unassociated with human disease (n = 99) contained ~65% more nucleotide diversity compared to clinical-sporadic (n = 139) or outbreak-associated (n = 28) ST1 subgroups. The accessory pangenome of environmental isolates was also ~30-60% larger than other subgroups and was enriched for transposition and conjugative transfer-associated elements. Up to ~10% of US ST1 genetic variation could be explained by geographic origin, but considerable genetic conservation existed among strains isolated from geographically distant states and from different decades. These findings provide new insight into the ST1 population structure and establish a foundation for interpreting genetic relationships among ST1 strains; these data may also inform future analyses for improved outbreak investigations

Environmental and biological factors are joint drivers of mercury biomagnification in subarctic lake food webs along a climate and productivity gradient

Subarctic lakes are getting warmer and more productive due to the joint effects of climate change and intensive land-use practices (e.g. forest clear-cutting and peatland ditching), processes that potentially increase leaching of peat- and soil-stored mercury into lake ecosystems. We sampled biotic communities from primary producers (algae) to top consumers (piscivorous fish), in 19 subarctic lakes situated on a latitudinal (69.0–66.5° N), climatic (+3.2 °C temperature and +30% precipitation from north to south) and catchment land-use (pristine to intensive forestry areas) gradient. We first tested how the joint effects of climate and productivity influence mercury biomagnification in food webs focusing on the trophic magnification slope (TMS) and mercury baseline (THg baseline) level, both derived from linear regression between total mercury (log10THg) and organism trophic level (TL). We examined a suite of environmental and biotic variables thought to explain THg baseline and TMS with stepwise generalized multiple regression models. Finally, we assessed how climate and lake productivity affect the THg content of top predators in subarctic lakes. We found biomagnification of mercury in all studied lakes, but with variable TMS and THg baseline values. In stepwise multiple regression models, TMS was best explained by negative relationships with food chain length, climate-productivity gradient, catchment properties, and elemental C:N ratio of the top predator (full model R2 = 0.90, p < 0.001). The model examining variation in THg baseline values included the same variables with positive relationships (R2 = 0.69, p = 0.014). Mass-standardized THg content of a common top predator (1 kg northern pike, Esox lucius) increased towards warmer and more productive lakes. Results indicate that increasing eutrophication via forestry-related land-use activities increase the THg levels at the base of the food web and in top predators, suggesting that the sources of nutrients and mercury should be considered in future bioaccumulation and biomagnification studies